1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 10
6 * The 'set disassembler-options' command now supports specifying options
9 * GDB now supports general memory tagging functionality if the underlying
10 architecture supports the proper primitives and hooks. Currently this is
11 enabled only for AArch64 MTE.
15 - Additional information when the inferior crashes with a SIGSEGV caused by
16 a memory tag violation.
18 - A new modifier 'm' for the "x" command, which displays allocation tags for a
19 particular memory range.
21 - Display of memory tag mismatches by "print", for addresses and
22 pointers, if memory tagging is supported by the architecture.
24 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
29 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
31 The MI -break-insert and -dprintf-insert commands now support a
32 new "--qualified" option that makes GDB interpret a specified
33 function name as a complete fully-qualified name. This is the
34 equivalent of the CLI's "break -qualified" and "dprintf
37 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
39 The MI -break-insert and -dprintf-insert commands now support a
40 '--force-condition' flag to forcibly define a condition even when
41 the condition is invalid at all locations of the breakpoint. This
42 is equivalent to the '-force-condition' flag of the CLI's "break"
45 ** '-break-condition --force'
47 The MI -break-condition command now supports a '--force' flag to
48 forcibly define a condition even when the condition is invalid at
49 all locations of the selected breakpoint. This is equivalent to
50 the '-force' flag of the CLI's "cond" command.
52 ** '-file-list-exec-source-files [--basename | --dirname] [--] [REGEXP]'
54 The existing -file-list-exec-source-files command now takes an
55 optional REGEXP which is used to filter the source files that are
56 included in the results.
58 By default REGEXP is matched against the full filename of the
59 source file. When one of --basename or --dirname is given then
60 REGEXP is only matched against the specified part of the full
63 The results from -file-list-exec-source-files now include a
64 'debug-fully-read' field which takes the value 'true' or 'false'.
65 A 'true' value indicates the source file is from a compilation
66 unit that has had its debug information fully read in by GDB, a
67 value of 'false' indicates GDB has only performed a partial scan
68 of the debug information so far.
70 * GDB now supports core file debugging for x86_64 Cygwin programs.
72 * GDB will now look for the .gdbinit file in a config directory before
73 looking for ~/.gdbinit. The file is searched for in the following
74 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
75 $HOME/.gdbinit. On Apple hosts the search order is instead:
76 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
78 * GDB now supports fixed point types which are described in DWARF
79 as base types with a fixed-point encoding. Additionally, support
80 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
83 For Ada, this allows support for fixed point types without requiring
84 the use of the GNAT encoding (based on information added to the type's
85 name following a GNAT-specific format).
87 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
88 or ~/.gdbearlyinit if these files are present. These files are
89 processed earlier than any of the other initialization files and
90 can affect parts of GDB's startup that previously had already been
91 completed before the initialization files were read, for example
92 styling of the initial GDB greeting.
94 * GDB now has two new options "--early-init-command" and
95 "--early-init-eval-command" with corresponding short options "-eix"
96 and "-eiex" that allow options (that would normally appear in a
97 gdbearlyinit file) to be passed on the command line.
99 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
100 now understood by GDB, and can be used to describe the vector
101 registers of a target. The precise requirements of this register
102 feature are documented in the GDB manual.
107 show debug event-loop
108 Control the display of debug output about GDB's event loop.
110 set print memory-tag-violations
111 show print memory-tag-violations
112 Control whether to display additional information about memory tag violations
113 when printing pointers and addresses. Architecture support for memory
114 tagging is required for this option to have an effect.
116 maintenance flush symbol-cache
117 maintenance flush register-cache
118 These new commands are equivalent to the already existing commands
119 'maintenance flush-symbol-cache' and 'flushregs' respectively.
121 maintenance flush dcache
122 A new command to flush the dcache.
124 maintenance info target-sections
125 Print GDB's internal target sections table.
127 memory-tag show-logical-tag POINTER
128 Print the logical tag for POINTER.
129 memory-tag with-logical-tag POINTER TAG
130 Print POINTER with logical tag TAG.
131 memory-tag show-allocation-tag ADDRESS
132 Print the allocation tag for ADDRESS.
133 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
134 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
135 memory-tag check POINTER
136 Validate that POINTER's logical tag matches the allocation tag.
138 set startup-quietly on|off
140 When 'on', this causes GDB to act as if "-silent" were passed on the
141 command line. This command needs to be added to an early
142 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
145 set print type hex on|off
147 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
148 and offsets of struct members. When 'off', decimal notation is used.
150 set python ignore-environment on|off
151 show python ignore-environment
152 When 'on', this causes GDB's builtin Python to ignore any
153 environment variables that would otherwise affect how Python
154 behaves. This command needs to be added to an early initialization
155 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
157 set python dont-write-bytecode auto|on|off
158 show python dont-write-bytecode
159 When 'on', this causes GDB's builtin Python to not write any
160 byte-code (.pyc files) to disk. This command needs to be added to
161 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
162 order to affect GDB. When 'off' byte-code will always be written.
163 When set to 'auto' (the default) Python will check the
164 PYTHONDONTWRITEBYTECODE environment variable.
168 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
169 [-force-condition] [if CONDITION]
170 This command would previously refuse setting a breakpoint if the
171 CONDITION expression is invalid at a location. It now accepts and
172 defines the breakpoint if there is at least one location at which
173 the CONDITION is valid. The locations for which the CONDITION is
174 invalid, are automatically disabled. If CONDITION is invalid at all
175 of the locations, setting the breakpoint is still rejected. However,
176 the '-force-condition' flag can be used in this case for forcing GDB to
177 define the breakpoint, making all the current locations automatically
178 disabled. This may be useful if the user knows the condition will
179 become meaningful at a future location, e.g. due to a shared library
182 condition [-force] N COND
183 The behavior of this command is changed the same way for the 'break'
184 command as explained above. The '-force' flag can be used to force
185 GDB into defining the condition even when COND is invalid for all the
186 current locations of breakpoint N.
189 maintenance flush-symbol-cache
190 These commands are deprecated in favor of the new commands
191 'maintenance flush register-cache' and 'maintenance flush
192 symbol-cache' respectively.
194 set style version foreground COLOR
195 set style version background COLOR
196 set style version intensity VALUE
197 Control the styling of GDB's version number text.
200 When the ID parameter is omitted, then this command prints information
201 about the current inferior. When the ID parameter is present, the
202 behavior of the command is unchanged and have the inferior ID become
203 the current inferior.
205 maintenance info sections
206 The ALLOBJ keyword has been replaced with an -all-objects command
207 line flag. It is now possible to filter which sections are printed
208 even when -all-objects is passed.
210 ptype[/FLAGS] TYPE | EXPRESSION
211 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
212 notation is used when printing sizes and offsets of struct members.
213 When '/d' is set, decimal notation is used when printing sizes and
214 offsets of struct members. Default behavior is given by 'show print
217 * Removed targets and native configurations
219 ARM Symbian arm*-*-symbianelf*
224 Request the remote to send allocation tags for a particular memory range.
226 Request the remote to store the specified allocation tags to the requested
231 ** Improved support for rvalue reference values:
232 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
233 value-referenced-value procedure now handles rvalue reference
236 ** New procedures for obtaining value variants:
237 value-reference-value, value-rvalue-reference-value and
242 ** Inferior objects now contain a read-only 'connection_num' attribute that
243 gives the connection number as seen in 'info connections' and
246 ** New method gdb.Frame.level() which returns the stack level of the
249 ** New method gdb.PendingFrame.level() which returns the stack level
252 ** When hitting a catchpoint, the Python API will now emit a
253 gdb.BreakpointEvent rather than a gdb.StopEvent. The
254 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
256 *** Changes in GDB 10
258 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
259 and "org.gnu.gdb.arc.aux". The old names are still supported but
260 must be considered obsolete. They will be deprecated after some
263 * Help and apropos commands will now show the documentation of a
264 command only once, even if that command has one or more aliases.
265 These commands now show the command name, then all of its aliases,
266 and finally the description of the command.
268 * 'help aliases' now shows only the user defined aliases. GDB predefined
269 aliases are shown together with their aliased command.
271 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
272 debugging information as well as source code.
274 When built with debuginfod, GDB can automatically query debuginfod
275 servers for the separate debug files and source code of the executable
278 To build GDB with debuginfod, pass --with-debuginfod to configure (this
279 requires libdebuginfod, the debuginfod client library).
281 debuginfod is distributed with elfutils, starting with version 0.178.
283 You can get the latest version from https://sourceware.org/elfutils.
285 * Multi-target debugging support
287 GDB now supports debugging multiple target connections
288 simultaneously. For example, you can now have each inferior
289 connected to different remote servers running in different machines,
290 or have one inferior debugging a local native process, an inferior
291 debugging a core dump, etc.
293 This support is experimental and comes with some limitations -- you
294 can only resume multiple targets simultaneously if all targets
295 support non-stop mode, and all remote stubs or servers must support
296 the same set of remote protocol features exactly. See also "info
297 connections" and "add-inferior -no-connection" below, and "maint set
298 target-non-stop" in the user manual.
300 * New features in the GDB remote stub, GDBserver
302 ** GDBserver is now supported on ARC GNU/Linux.
304 ** GDBserver is now supported on RISC-V GNU/Linux.
306 ** GDBserver no longer supports these host triplets:
317 i[34567]86-*-mingw32ce*
319 * Debugging MS-Windows processes now sets $_exitsignal when the
320 inferior is terminated by a signal, instead of setting $_exitcode.
322 * Multithreaded symbol loading has now been enabled by default on systems
323 that support it (see entry for GDB 9, below), providing faster
324 performance for programs with many symbols.
326 * The $_siginfo convenience variable now also works on Windows targets,
327 and will display the EXCEPTION_RECORD of the last handled exception.
329 * TUI windows can now be arranged horizontally.
331 * The command history filename can now be set to the empty string
332 either using 'set history filename' or by setting 'GDBHISTFILE=' in
333 the environment. The effect of setting this filename to the empty
334 string is that GDB will not try to load any previous command
337 * On Windows targets, it is now possible to debug 32-bit programs with a
342 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
343 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
344 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
345 running process, this new option indicates whether to detect
346 a mismatch between the current executable file loaded by GDB and the
347 executable file used to start the process. If 'ask', the default,
348 display a warning and ask the user whether to load the process
349 executable file; if 'warn', just display a warning; if 'off', don't
350 attempt to detect a mismatch.
352 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
353 Define a new TUI layout, specifying its name and the windows that
356 maintenance print xml-tdesc [FILE]
357 Prints the current target description as an XML document. If the
358 optional FILE is provided (which is an XML target description) then
359 the target description is read from FILE into GDB, and then
362 maintenance print core-file-backed-mappings
363 Prints file-backed mappings loaded from a core file's note section.
364 Output is expected to be similar to that of "info proc mappings".
366 set debug fortran-array-slicing on|off
367 show debug fortran-array-slicing
368 Print debugging when taking slices of Fortran arrays.
370 set fortran repack-array-slices on|off
371 show fortran repack-array-slices
372 When taking slices from Fortran arrays and strings, if the slice is
373 non-contiguous within the original value then, when this option is
374 on, the new value will be repacked into a single contiguous value.
375 When this option is off, then the value returned will consist of a
376 descriptor that describes the slice within the memory of the
377 original parent value.
381 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
382 The alias command can now specify default args for an alias.
383 GDB automatically prepends the alias default args to the argument list
384 provided explicitly by the user.
385 For example, to have a backtrace with full details, you can define
387 'alias bt_ALL = backtrace -entry-values both -frame-arg all
388 -past-main -past-entry -full'.
389 Alias default arguments can also use a set of nested 'with' commands,
390 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
391 defines the alias pp10 that will pretty print a maximum of 10 elements
392 of the given expression (if the expression is an array).
396 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
401 ** gdb.register_window_type can be used to implement new TUI windows
404 ** Dynamic types can now be queried. gdb.Type has a new attribute,
405 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
406 field of a dynamic type may have None for its "bitpos" attribute
409 ** Commands written in Python can be in the "TUI" help class by
410 registering with the new constant gdb.COMMAND_TUI.
412 ** New method gdb.PendingFrame.architecture () to retrieve the
413 architecture of the pending frame.
415 ** New gdb.Architecture.registers method that returns a
416 gdb.RegisterDescriptorIterator object, an iterator that returns
417 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
418 way to query the registers available for an architecture.
420 ** New gdb.Architecture.register_groups method that returns a
421 gdb.RegisterGroupIterator object, an iterator that returns
422 gdb.RegisterGroup objects. The new RegisterGroup is a way to
423 discover the available register groups.
427 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
429 ** Procedures 'memory-port-read-buffer-size',
430 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
431 and 'set-memory-port-write-buffer-size!' are deprecated. When
432 using Guile 2.2 and later, users who need to control the size of
433 a memory port's internal buffer can use the 'setvbuf' procedure.
437 * 'thread-exited' event is now available in the annotations interface.
439 * New built-in convenience variables $_gdb_major and $_gdb_minor
440 provide the GDB version. They are handy for conditionally using
441 features available only in or since specific GDB versions, in
442 scripts that should work error-free with many different versions,
443 such as in system-wide init files.
445 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
446 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
447 of the GDB settings and the GDB maintenance settings. They are handy
448 for changing the logic of user defined commands depending on the
449 current GDB settings.
451 * GDB now supports Thread Local Storage (TLS) variables on several
452 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
453 architectures require kernel changes. TLS is not yet supported for
454 amd64 and i386 process core dumps.
456 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
457 addresses that required unmasking are shown in the backtrace with the
460 * Two new convenience functions $_cimag and $_creal that extract the
461 imaginary and real parts respectively from complex numbers.
463 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
464 provide the exitcode or exit status of the shell commands launched by
465 GDB commands such as "shell", "pipe" and "make".
467 * The command define-prefix can now define user defined prefix commands.
468 User defined commands can now be defined using these user defined prefix
471 * Command names can now use the . character.
473 * The RX port now supports XML target descriptions.
475 * GDB now shows the Ada task names at more places, e.g. in task switching
478 * GDB can now be compiled with Python 3 on Windows.
480 * New convenience variable $_ada_exception holds the address of the
481 Ada exception being thrown. This is set by Ada-related catchpoints.
483 * GDB can now place breakpoints on nested functions and subroutines in
484 Fortran code. The '::' operator can be used between parent and
485 child scopes when placing breakpoints, for example:
487 (gdb) break outer_function::inner_function
489 The 'outer_function::' prefix is only needed if 'inner_function' is
490 not visible in the current scope.
492 * In addition to the system-wide gdbinit file, if configured with
493 --with-system-gdbinit-dir, GDB will now also load files in that directory
494 as system gdbinit files, unless the -nx or -n flag is provided. Files
495 with extensions .gdb, .py and .scm are supported as long as GDB was
496 compiled with support for that language.
498 * GDB now supports multithreaded symbol loading for higher performance.
499 This feature is still in testing, so it is disabled by default. You
500 can turn it on using 'maint set worker-threads unlimited'.
504 ** The gdb.Value type has a new method 'format_string' which returns a
505 string representing the value. The formatting is controlled by the
506 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
507 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
508 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
510 ** gdb.Type has a new property 'objfile' which returns the objfile the
513 ** The frame information printed by the python frame filtering code
514 is now consistent with what the 'backtrace' command prints when
515 there are no filters, or when the 'backtrace' '-no-filters' option
518 ** The new function gdb.lookup_static_symbol can be used to look up
519 symbols with static linkage.
521 ** The new function gdb.lookup_static_symbols can be used to look up
522 all static symbols with static linkage.
524 ** gdb.Objfile has new methods 'lookup_global_symbol' and
525 'lookup_static_symbol' to lookup a symbol from this objfile only.
527 ** gdb.Block now supports the dictionary syntax for accessing symbols in
528 this block (e.g. block['local_variable']).
532 | [COMMAND] | SHELL_COMMAND
533 | -d DELIM COMMAND DELIM SHELL_COMMAND
534 pipe [COMMAND] | SHELL_COMMAND
535 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
536 Executes COMMAND and sends its output to SHELL_COMMAND.
537 With no COMMAND, repeat the last executed command
538 and send its output to SHELL_COMMAND.
540 define-prefix COMMAND
541 Define or mark a command as a user-defined prefix command.
543 with SETTING [VALUE] [-- COMMAND]
544 w SETTING [VALUE] [-- COMMAND]
545 Temporarily set SETTING, run COMMAND, and restore SETTING.
546 Usage: with SETTING -- COMMAND
547 With no COMMAND, repeats the last executed command.
548 SETTING is any GDB setting you can change with the "set"
549 subcommands. For example, 'with language c -- print someobj'
550 temporarily switches to the C language in order to print someobj.
551 Settings can be combined: 'w lang c -- w print elements unlimited --
552 usercmd' switches to the C language and runs usercmd with no limit
553 of array elements to print.
555 maint with SETTING [VALUE] [-- COMMAND]
556 Like "with", but works with "maintenance set" settings.
558 set may-call-functions [on|off]
559 show may-call-functions
560 This controls whether GDB will attempt to call functions in
561 the program, such as with expressions in the print command. It
562 defaults to on. Calling functions in the program being debugged
563 can have undesired side effects. It is now possible to forbid
564 such function calls. If function calls are forbidden, GDB will throw
565 an error when a command (such as print expression) calls a function
568 set print finish [on|off]
570 This controls whether the `finish' command will display the value
571 that is returned by the current function. When `off', the value is
572 still entered into the value history, but it is not printed. The
577 Allows deeply nested structures to be simplified when printing by
578 replacing deeply nested parts (beyond the max-depth) with ellipses.
579 The default max-depth is 20, but this can be set to unlimited to get
580 the old behavior back.
582 set print raw-values [on|off]
583 show print raw-values
584 By default, GDB applies the enabled pretty printers when printing a
585 value. This allows to ignore the enabled pretty printers for a series
586 of commands. The default is 'off'.
588 set logging debugredirect [on|off]
589 By default, GDB debug output will go to both the terminal and the logfile.
590 Set if you want debug output to go only to the log file.
592 set style title foreground COLOR
593 set style title background COLOR
594 set style title intensity VALUE
595 Control the styling of titles.
597 set style highlight foreground COLOR
598 set style highlight background COLOR
599 set style highlight intensity VALUE
600 Control the styling of highlightings.
602 maint set worker-threads
603 maint show worker-threads
604 Control the number of worker threads that can be used by GDB. The
605 default is 0. "unlimited" lets GDB choose a number that is
606 reasonable. Currently worker threads are only used when demangling
607 the names of linker symbols.
609 set style tui-border foreground COLOR
610 set style tui-border background COLOR
611 Control the styling of TUI borders.
613 set style tui-active-border foreground COLOR
614 set style tui-active-border background COLOR
615 Control the styling of the active TUI border.
617 maint set test-settings KIND
618 maint show test-settings KIND
619 A set of commands used by the testsuite for exercising the settings
622 maint set tui-resize-message [on|off]
623 maint show tui-resize-message
624 Control whether GDB prints a message each time the terminal is
625 resized when in TUI mode. This is primarily useful for testing the
628 set print frame-info [short-location|location|location-and-address
629 |source-and-location|source-line|auto]
630 show print frame-info
631 This controls what frame information is printed by the commands printing
632 a frame. This setting will e.g. influence the behaviour of 'backtrace',
633 'frame', 'stepi'. The python frame filtering also respect this setting.
634 The 'backtrace' '-frame-info' option can override this global setting.
636 set tui compact-source
637 show tui compact-source
639 Enable the "compact" display mode for the TUI source window. The
640 compact display uses only as much space as is needed for the line
641 numbers in the current file, and only a single space to separate the
642 line numbers from the source.
644 info modules [-q] [REGEXP]
645 Return a list of Fortran modules matching REGEXP, or all modules if
648 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
649 Return a list of functions within all modules, grouped by module.
650 The list of functions can be restricted with the optional regular
651 expressions. MODULE_REGEXP matches against the module name,
652 TYPE_REGEXP matches against the function type signature, and REGEXP
653 matches against the function name.
655 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
656 Return a list of variables within all modules, grouped by module.
657 The list of variables can be restricted with the optional regular
658 expressions. MODULE_REGEXP matches against the module name,
659 TYPE_REGEXP matches against the variable type, and REGEXP matches
660 against the variable name.
662 set debug remote-packet-max-chars
663 show debug remote-packet-max-chars
664 Controls the number of characters to output in a remote packet when using
666 The default is 512 bytes.
669 Lists the target connections currently in use.
674 The "help" command uses the title style to enhance the
675 readibility of its output by styling the classes and
679 Similarly to "help", the "apropos" command also uses the
680 title style for the command names. "apropos" accepts now
681 a flag "-v" (verbose) to show the full documentation
682 of matching commands and to use the highlight style to mark
683 the documentation parts matching REGEXP.
687 The GDB printf and eval commands can now print C-style and Ada-style
688 string convenience variables without calling functions in the program.
689 This allows to do formatted printing of strings without having
690 a running inferior, or when debugging a core dump.
692 info sources [-dirname | -basename] [--] [REGEXP]
693 This command has now optional arguments to only print the files
694 whose names match REGEXP. The arguments -dirname and -basename
695 allow to restrict matching respectively to the dirname and basename
699 The "show style" and its subcommands are now styling
700 a style name in their output using its own style, to help
701 the user visualize the different styles.
703 set print frame-arguments
704 The new value 'presence' indicates to only indicate the presence of
705 arguments using ..., instead of printing argument names and values.
707 set print raw-frame-arguments
708 show print raw-frame-arguments
710 These commands replace the similarly-named "set/show print raw
711 frame-arguments" commands (now with a dash instead of a space). The
712 old commands are now deprecated and may be removed in a future
715 add-inferior [-no-connection]
716 The add-inferior command now supports a "-no-connection" flag that
717 makes the new inferior start with no target connection associated.
718 By default, the new inferior inherits the target connection of the
719 current inferior. See also "info connections".
722 This command's output now includes a new "Connection" column
723 indicating which target connection an inferior is bound to. See
724 "info connections" above.
726 maint test-options require-delimiter
727 maint test-options unknown-is-error
728 maint test-options unknown-is-operand
729 maint show test-options-completion-result
730 Commands used by the testsuite to validate the command options
733 focus, winheight, +, -, >, <
734 These commands are now case-sensitive.
736 * New command options, command completion
738 GDB now has a standard infrastructure to support dash-style command
739 options ('-OPT'). One benefit is that commands that use it can
740 easily support completion of command line arguments. Try "CMD
741 -[TAB]" or "help CMD" to find options supported by a command. Over
742 time, we intend to migrate most commands to this infrastructure. A
743 number of commands got support for new command options in this
746 ** The "print" and "compile print" commands now support a number of
747 options that allow overriding relevant global print settings as
748 set by "set print" subcommands:
752 -array-indexes [on|off]
753 -elements NUMBER|unlimited
758 -repeats NUMBER|unlimited
759 -static-members [on|off]
764 Note that because the "print"/"compile print" commands accept
765 arbitrary expressions which may look like options (including
766 abbreviations), if you specify any command option, then you must
767 use a double dash ("--") to mark the end of argument processing.
769 ** The "backtrace" command now supports a number of options that
770 allow overriding relevant global print settings as set by "set
771 backtrace" and "set print" subcommands:
773 -entry-values no|only|preferred|if-needed|both|compact|default
774 -frame-arguments all|scalars|none
775 -raw-frame-arguments [on|off]
776 -frame-info auto|source-line|location|source-and-location
777 |location-and-address|short-location
781 In addition, the full/no-filters/hide qualifiers are now also
782 exposed as command options too:
788 ** The "frame apply", "tfaas" and "faas" commands similarly now
789 support the following options:
794 ** The new "info sources" options -dirname and -basename options
795 are using the standard '-OPT' infrastructure.
797 All options above can also be abbreviated. The argument of boolean
798 (on/off) options can be 0/1 too, and also the argument is assumed
799 "on" if omitted. This allows writing compact command invocations,
802 (gdb) p -ra -p -o 0 -- *myptr
804 The above is equivalent to:
806 (gdb) print -raw-values -pretty -object off -- *myptr
808 ** The "info types" command now supports the '-q' flag to disable
809 printing of some header information in a similar fashion to "info
810 variables" and "info functions".
812 ** The "info variables", "info functions", and "whereis" commands
813 now take a '-n' flag that excludes non-debug symbols (symbols
814 from the symbol table, not from the debug info such as DWARF)
817 * Completion improvements
819 ** GDB can now complete the options of the "thread apply all" and
820 "taas" commands, and their "-ascending" option can now be
823 ** GDB can now complete the options of the "info threads", "info
824 functions", "info variables", "info locals", and "info args"
827 ** GDB can now complete the options of the "compile file" and
828 "compile code" commands. The "compile file" command now
829 completes on filenames.
831 ** GDB can now complete the backtrace command's
832 "full/no-filters/hide" qualifiers.
834 * In settings, you can now abbreviate "unlimited".
836 E.g., "set print elements u" is now equivalent to "set print
842 This lists all the possible completions for the rest of the line, if it
843 were to be given as a command itself. This is intended for use by MI
844 frontends in cases when separate CLI and MI channels cannot be used.
846 -catch-throw, -catch-rethrow, and -catch-catch
847 These can be used to catch C++ exceptions in a similar fashion to
848 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
850 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
851 These commands are the MI equivalent of the CLI commands 'info
852 functions', 'info types', and 'info variables' respectively.
854 -symbol-info-modules, this is the MI equivalent of the CLI 'info
857 -symbol-info-module-functions and -symbol-info-module-variables.
858 These commands are the MI equivalent of the CLI commands 'info
859 module functions' and 'info module variables'.
863 ** The default version of the MI interpreter is now 3 (-i=mi3).
865 ** The output of information about multi-location breakpoints (which is
866 syntactically incorrect in MI 2) has changed in MI 3. This affects
867 the following commands and events:
871 - =breakpoint-created
872 - =breakpoint-modified
874 The -fix-multi-location-breakpoint-output command can be used to enable
875 this behavior with previous MI versions.
877 ** Backtraces and frames include a new optional field addr_flags which is
878 given after the addr field. On AArch64 this contains PAC if the address
879 has been masked in the frame. On all other targets the field is not
884 The testsuite now creates the files gdb.cmd (containing the arguments
885 used to launch GDB) and gdb.in (containing all the commands sent to
886 GDB) in the output directory for each test script. Multiple invocations
887 are appended with .1, .2, .3 etc.
889 * Building GDB and GDBserver now requires GNU make >= 3.82.
891 Using another implementation of the make program or an earlier version of
892 GNU make to build GDB or GDBserver is not supported.
894 * Building GDB now requires GNU readline >= 7.0.
896 GDB now bundles GNU readline 8.0, but if you choose to use
897 --with-system-readline, only readline >= 7.0 can be used.
899 * The TUI SingleKey keymap is now named "SingleKey". This can be used
900 from .inputrc to bind keys in this keymap. This feature is only
901 available when gdb is built against GNU readline 8.0 or later.
903 * Removed targets and native configurations
905 GDB no longer supports debugging the Cell Broadband Engine. This includes
906 both debugging standalone Cell/B.E. SPU applications and integrated debugging
907 of Cell/B.E. applications that use both the PPU and SPU architectures.
913 * Removed targets and native configurations
915 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
918 *** Changes in GDB 8.3
920 * GDB and GDBserver now support access to additional registers on
921 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
924 * GDB now has experimental support for the compilation and injection of
925 C++ source code into the inferior. This beta release does not include
926 support for several language features, such as templates, constructors,
929 This feature requires GCC 7.1 or higher built with libcp1.so
932 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
933 can be passed using the '[ADDRESS]:PORT' notation, or the regular
934 'ADDRESS:PORT' method.
936 * DWARF index cache: GDB can now automatically save indices of DWARF
937 symbols on disk to speed up further loading of the same binaries.
939 * Ada task switching is now supported on aarch64-elf targets when
940 debugging a program using the Ravenscar Profile. For more information,
941 see the "Tasking Support when using the Ravenscar Profile" section
942 in the GDB user manual.
944 * GDB in batch mode now exits with status 1 if the last command to be
947 * The RISC-V target now supports target descriptions.
949 * System call catchpoints now support system call aliases on FreeBSD.
950 When the ABI of a system call changes in FreeBSD, this is
951 implemented by leaving a compatibility system call using the old ABI
952 at the existing number and allocating a new system call number for
953 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
954 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
955 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
956 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
957 so that a system call catchpoint for the 'kevent' system call will
958 catch invocations of both the 'kevent' and 'freebsd11_kevent'
959 binaries. This ensures that 'kevent' system calls are caught for
960 binaries using either the old or new ABIs.
962 * Terminal styling is now available for the CLI and the TUI. GNU
963 Source Highlight can additionally be used to provide styling of
964 source code snippets. See the "set style" commands, below, for more
967 * Removed support for old demangling styles arm, edg, gnu, hp and
972 set debug compile-cplus-types
973 show debug compile-cplus-types
974 Control the display of debug output about type conversion in the
975 C++ compile feature. Commands have no effect while compiling
980 Control whether debug output about files/functions skipping is
983 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
984 Apply a command to some frames.
985 FLAG arguments allow to control what output to produce and how to handle
986 errors raised when applying COMMAND to a frame.
989 Apply a command to all threads (ignoring errors and empty output).
990 Shortcut for 'thread apply all -s COMMAND'.
993 Apply a command to all frames (ignoring errors and empty output).
994 Shortcut for 'frame apply all -s COMMAND'.
997 Apply a command to all frames of all threads (ignoring errors and empty
999 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1001 maint set dwarf unwinders (on|off)
1002 maint show dwarf unwinders
1003 Control whether DWARF unwinders can be used.
1006 Display a list of open files for a process.
1010 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1011 These commands all now take a frame specification which
1012 is either a frame level, or one of the keywords 'level', 'address',
1013 'function', or 'view' followed by a parameter. Selecting a frame by
1014 address, or viewing a frame outside the current backtrace now
1015 requires the use of a keyword. Selecting a frame by level is
1016 unchanged. The MI comment "-stack-select-frame" is unchanged.
1018 target remote FILENAME
1019 target extended-remote FILENAME
1020 If FILENAME is a Unix domain socket, GDB will attempt to connect
1021 to this socket instead of opening FILENAME as a character device.
1023 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1024 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1025 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1026 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1027 These commands can now print only the searched entities
1028 matching the provided regexp(s), giving a condition
1029 on the entity names or entity types. The flag -q disables
1030 printing headers or informations messages.
1036 These commands now determine the syntax for the shown entities
1037 according to the language chosen by `set language'. In particular,
1038 `set language auto' means to automatically choose the language of
1041 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1042 The 'thread apply' command accepts new FLAG arguments.
1043 FLAG arguments allow to control what output to produce and how to handle
1044 errors raised when applying COMMAND to a thread.
1046 set tui tab-width NCHARS
1047 show tui tab-width NCHARS
1048 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1050 set style enabled [on|off]
1052 Enable or disable terminal styling. Styling is enabled by default
1053 on most hosts, but disabled by default when in batch mode.
1055 set style sources [on|off]
1057 Enable or disable source code styling. Source code styling is
1058 enabled by default, but only takes effect if styling in general is
1059 enabled, and if GDB was linked with GNU Source Highlight.
1061 set style filename foreground COLOR
1062 set style filename background COLOR
1063 set style filename intensity VALUE
1064 Control the styling of file names.
1066 set style function foreground COLOR
1067 set style function background COLOR
1068 set style function intensity VALUE
1069 Control the styling of function names.
1071 set style variable foreground COLOR
1072 set style variable background COLOR
1073 set style variable intensity VALUE
1074 Control the styling of variable names.
1076 set style address foreground COLOR
1077 set style address background COLOR
1078 set style address intensity VALUE
1079 Control the styling of addresses.
1083 ** The '-data-disassemble' MI command now accepts an '-a' option to
1084 disassemble the whole function surrounding the given program
1085 counter value or function name. Support for this feature can be
1086 verified by using the "-list-features" command, which should
1087 contain "data-disassemble-a-option".
1089 ** Command responses and notifications that include a frame now include
1090 the frame's architecture in a new "arch" attribute.
1092 * New native configurations
1094 GNU/Linux/RISC-V riscv*-*-linux*
1095 FreeBSD/riscv riscv*-*-freebsd*
1099 GNU/Linux/RISC-V riscv*-*-linux*
1100 CSKY ELF csky*-*-elf
1101 CSKY GNU/LINUX csky*-*-linux
1102 FreeBSD/riscv riscv*-*-freebsd*
1104 GNU/Linux/OpenRISC or1k*-*-linux*
1108 GDB no longer supports native debugging on versions of MS-Windows
1113 ** GDB no longer supports Python versions less than 2.6.
1115 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1116 space associated to that inferior.
1118 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1119 of objfiles associated to that program space.
1121 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1122 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1125 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1126 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1127 correct and did not work properly.
1129 ** The gdb.Value type has a new constructor, which is used to construct a
1130 gdb.Value from a Python buffer object and a gdb.Type.
1136 Enable or disable the undefined behavior sanitizer. This is
1137 disabled by default, but passing --enable-ubsan=yes or
1138 --enable-ubsan=auto to configure will enable it. Enabling this can
1139 cause a performance penalty. The undefined behavior sanitizer was
1140 first introduced in GCC 4.9.
1142 *** Changes in GDB 8.2
1144 * The 'set disassembler-options' command now supports specifying options
1145 for the MIPS target.
1147 * The 'symbol-file' command now accepts an '-o' option to add a relative
1148 offset to all sections.
1150 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1151 a relative offset to all sections, but it allows to override the load
1152 address of individual sections using '-s'.
1154 * The 'add-symbol-file' command no longer requires the second argument
1155 (address of the text section).
1157 * The endianness used with the 'set endian auto' mode in the absence of
1158 an executable selected for debugging is now the last endianness chosen
1159 either by one of the 'set endian big' and 'set endian little' commands
1160 or by inferring from the last executable used, rather than the startup
1163 * The pager now allows a "c" response, meaning to disable the pager
1164 for the rest of the current command.
1166 * The commands 'info variables/functions/types' now show the source line
1167 numbers of symbol definitions when available.
1169 * 'info proc' now works on running processes on FreeBSD systems and core
1170 files created on FreeBSD systems.
1172 * C expressions can now use _Alignof, and C++ expressions can now use
1175 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1176 the vector length while the process is running.
1182 Control display of debugging info regarding the FreeBSD native target.
1184 set|show varsize-limit
1185 This new setting allows the user to control the maximum size of Ada
1186 objects being printed when those objects have a variable type,
1187 instead of that maximum size being hardcoded to 65536 bytes.
1189 set|show record btrace cpu
1190 Controls the processor to be used for enabling errata workarounds for
1191 branch trace decode.
1193 maint check libthread-db
1194 Run integrity checks on the current inferior's thread debugging
1197 maint set check-libthread-db (on|off)
1198 maint show check-libthread-db
1199 Control whether to run integrity checks on inferior specific thread
1200 debugging libraries as they are loaded. The default is not to
1201 perform such checks.
1205 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1207 ** The commands attached to a breakpoint can be set by assigning to
1208 the breakpoint's "commands" field.
1210 ** gdb.execute can now execute multi-line gdb commands.
1212 ** The new functions gdb.convenience_variable and
1213 gdb.set_convenience_variable can be used to get and set the value
1214 of convenience variables.
1216 ** A gdb.Parameter will no longer print the "set" help text on an
1217 ordinary "set"; instead by default a "set" will be silent unless
1218 the get_set_string method returns a non-empty string.
1222 RiscV ELF riscv*-*-elf
1224 * Removed targets and native configurations
1226 m88k running OpenBSD m88*-*-openbsd*
1227 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1228 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1229 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1231 * Aarch64/Linux hardware watchpoints improvements
1233 Hardware watchpoints on unaligned addresses are now properly
1234 supported when running Linux kernel 4.10 or higher: read and access
1235 watchpoints are no longer spuriously missed, and all watchpoints
1236 lengths between 1 and 8 bytes are supported. On older kernels,
1237 watchpoints set on unaligned addresses are no longer missed, with
1238 the tradeoff that there is a possibility of false hits being
1243 --enable-codesign=CERT
1244 This can be used to invoke "codesign -s CERT" after building gdb.
1245 This option is useful on macOS, where code signing is required for
1246 gdb to work properly.
1248 --disable-gdbcli has been removed
1249 This is now silently accepted, but does nothing.
1251 *** Changes in GDB 8.1
1253 * GDB now supports dynamically creating arbitrary register groups specified
1254 in XML target descriptions. This allows for finer grain grouping of
1255 registers on systems with a large amount of registers.
1257 * The 'ptype' command now accepts a '/o' flag, which prints the
1258 offsets and sizes of fields in a struct, like the pahole(1) tool.
1260 * New "--readnever" command line option instructs GDB to not read each
1261 symbol file's symbolic debug information. This makes startup faster
1262 but at the expense of not being able to perform symbolic debugging.
1263 This option is intended for use cases where symbolic debugging will
1264 not be used, e.g., when you only need to dump the debuggee's core.
1266 * GDB now uses the GNU MPFR library, if available, to emulate target
1267 floating-point arithmetic during expression evaluation when the target
1268 uses different floating-point formats than the host. At least version
1269 3.1 of GNU MPFR is required.
1271 * GDB now supports access to the guarded-storage-control registers and the
1272 software-based guarded-storage broadcast control registers on IBM z14.
1274 * On Unix systems, GDB now supports transmitting environment variables
1275 that are to be set or unset to GDBserver. These variables will
1276 affect the environment to be passed to the remote inferior.
1278 To inform GDB of environment variables that are to be transmitted to
1279 GDBserver, use the "set environment" command. Only user set
1280 environment variables are sent to GDBserver.
1282 To inform GDB of environment variables that are to be unset before
1283 the remote inferior is started by the GDBserver, use the "unset
1284 environment" command.
1286 * Completion improvements
1288 ** GDB can now complete function parameters in linespecs and
1289 explicit locations without quoting. When setting breakpoints,
1290 quoting around functions names to help with TAB-completion is
1291 generally no longer necessary. For example, this now completes
1294 (gdb) b function(in[TAB]
1295 (gdb) b function(int)
1297 Related, GDB is no longer confused with completing functions in
1298 C++ anonymous namespaces:
1301 (gdb) b (anonymous namespace)::[TAB][TAB]
1302 (anonymous namespace)::a_function()
1303 (anonymous namespace)::b_function()
1305 ** GDB now has much improved linespec and explicit locations TAB
1306 completion support, that better understands what you're
1307 completing and offers better suggestions. For example, GDB no
1308 longer offers data symbols as possible completions when you're
1309 setting a breakpoint.
1311 ** GDB now TAB-completes label symbol names.
1313 ** The "complete" command now mimics TAB completion accurately.
1315 * New command line options (gcore)
1318 Dump all memory mappings.
1320 * Breakpoints on C++ functions are now set on all scopes by default
1322 By default, breakpoints on functions/methods are now interpreted as
1323 specifying all functions with the given name ignoring missing
1324 leading scopes (namespaces and classes).
1326 For example, assuming a C++ program with symbols named:
1331 both commands "break func()" and "break B::func()" set a breakpoint
1334 You can use the new flag "-qualified" to override this. This makes
1335 GDB interpret the specified function name as a complete
1336 fully-qualified name instead. For example, using the same C++
1337 program, the "break -q B::func" command sets a breakpoint on
1338 "B::func", only. A parameter has been added to the Python
1339 gdb.Breakpoint constructor to achieve the same result when creating
1340 a breakpoint from Python.
1342 * Breakpoints on functions marked with C++ ABI tags
1344 GDB can now set breakpoints on functions marked with C++ ABI tags
1345 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1346 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1348 Functions with a C++11 abi tag are demangled/displayed like this:
1350 function[abi:cxx11](int)
1353 You can now set a breakpoint on such functions simply as if they had
1356 (gdb) b function(int)
1358 Or if you need to disambiguate between tags, like:
1360 (gdb) b function[abi:other_tag](int)
1362 Tab completion was adjusted accordingly as well.
1366 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1367 gdb.new_thread are emitted. See the manual for further
1368 description of these.
1370 ** A new function, "gdb.rbreak" has been added to the Python API.
1371 This function allows the setting of a large number of breakpoints
1372 via a regex pattern in Python. See the manual for further details.
1374 ** Python breakpoints can now accept explicit locations. See the
1375 manual for a further description of this feature.
1378 * New features in the GDB remote stub, GDBserver
1380 ** GDBserver is now able to start inferior processes with a
1381 specified initial working directory.
1383 The user can set the desired working directory to be used from
1384 GDB using the new "set cwd" command.
1386 ** New "--selftest" command line option runs some GDBserver self
1387 tests. These self tests are disabled in releases.
1389 ** On Unix systems, GDBserver now does globbing expansion and variable
1390 substitution in inferior command line arguments.
1392 This is done by starting inferiors using a shell, like GDB does.
1393 See "set startup-with-shell" in the user manual for how to disable
1394 this from GDB when using "target extended-remote". When using
1395 "target remote", you can disable the startup with shell by using the
1396 new "--no-startup-with-shell" GDBserver command line option.
1398 ** On Unix systems, GDBserver now supports receiving environment
1399 variables that are to be set or unset from GDB. These variables
1400 will affect the environment to be passed to the inferior.
1402 * When catching an Ada exception raised with a message, GDB now prints
1403 the message in the catchpoint hit notification. In GDB/MI mode, that
1404 information is provided as an extra field named "exception-message"
1405 in the *stopped notification.
1407 * Trait objects can now be inspected When debugging Rust code. This
1408 requires compiler support which will appear in Rust 1.24.
1410 * New remote packets
1412 QEnvironmentHexEncoded
1413 Inform GDBserver of an environment variable that is to be passed to
1414 the inferior when starting it.
1417 Inform GDBserver of an environment variable that is to be unset
1418 before starting the remote inferior.
1421 Inform GDBserver that the environment should be reset (i.e.,
1422 user-set environment variables should be unset).
1425 Indicates whether the inferior must be started with a shell or not.
1428 Tell GDBserver that the inferior to be started should use a specific
1431 * The "maintenance print c-tdesc" command now takes an optional
1432 argument which is the file name of XML target description.
1434 * The "maintenance selftest" command now takes an optional argument to
1435 filter the tests to be run.
1437 * The "enable", and "disable" commands now accept a range of
1438 breakpoint locations, e.g. "enable 1.3-5".
1443 Set and show the current working directory for the inferior.
1445 set|show compile-gcc
1446 Set and show compilation command used for compiling and injecting code
1447 with the 'compile' commands.
1449 set debug separate-debug-file
1450 show debug separate-debug-file
1451 Control the display of debug output about separate debug file search.
1453 set dump-excluded-mappings
1454 show dump-excluded-mappings
1455 Control whether mappings marked with the VM_DONTDUMP flag should be
1456 dumped when generating a core file.
1458 maint info selftests
1459 List the registered selftests.
1462 Start the debugged program stopping at the first instruction.
1465 Control display of debugging messages related to OpenRISC targets.
1467 set|show print type nested-type-limit
1468 Set and show the limit of nesting level for nested types that the
1469 type printer will show.
1471 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1474 * Safer/improved support for debugging with no debug info
1476 GDB no longer assumes functions with no debug information return
1479 This means that GDB now refuses to call such functions unless you
1480 tell it the function's type, by either casting the call to the
1481 declared return type, or by casting the function to a function
1482 pointer of the right type, and calling that:
1484 (gdb) p getenv ("PATH")
1485 'getenv' has unknown return type; cast the call to its declared return type
1486 (gdb) p (char *) getenv ("PATH")
1487 $1 = 0x7fffffffe "/usr/local/bin:/"...
1488 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1489 $2 = 0x7fffffffe "/usr/local/bin:/"...
1491 Similarly, GDB no longer assumes that global variables with no debug
1492 info have type 'int', and refuses to print the variable's value
1493 unless you tell it the variable's type:
1496 'var' has unknown type; cast it to its declared type
1500 * New native configurations
1502 FreeBSD/aarch64 aarch64*-*-freebsd*
1503 FreeBSD/arm arm*-*-freebsd*
1507 FreeBSD/aarch64 aarch64*-*-freebsd*
1508 FreeBSD/arm arm*-*-freebsd*
1509 OpenRISC ELF or1k*-*-elf
1511 * Removed targets and native configurations
1513 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1515 *** Changes in GDB 8.0
1517 * GDB now supports access to the PKU register on GNU/Linux. The register is
1518 added by the Memory Protection Keys for Userspace feature which will be
1519 available in future Intel CPUs.
1521 * GDB now supports C++11 rvalue references.
1525 ** New functions to start, stop and access a running btrace recording.
1526 ** Rvalue references are now supported in gdb.Type.
1528 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1531 * Building GDB and GDBserver now requires a C++11 compiler.
1533 For example, GCC 4.8 or later.
1535 It is no longer possible to build GDB or GDBserver with a C
1536 compiler. The --disable-build-with-cxx configure option has been
1539 * Building GDB and GDBserver now requires GNU make >= 3.81.
1541 It is no longer supported to build GDB or GDBserver with another
1542 implementation of the make program or an earlier version of GNU make.
1544 * Native debugging on MS-Windows supports command-line redirection
1546 Command-line arguments used for starting programs on MS-Windows can
1547 now include redirection symbols supported by native Windows shells,
1548 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1549 as "run", "start", and "set args", as well as the corresponding MI
1552 * Support for thread names on MS-Windows.
1554 GDB now catches and handles the special exception that programs
1555 running on MS-Windows use to assign names to threads in the
1558 * Support for Java programs compiled with gcj has been removed.
1560 * User commands now accept an unlimited number of arguments.
1561 Previously, only up to 10 was accepted.
1563 * The "eval" command now expands user-defined command arguments.
1565 This makes it easier to process a variable number of arguments:
1570 eval "print $arg%d", $i
1575 * Target descriptions can now describe registers for sparc32 and sparc64.
1577 * GDB now supports DWARF version 5 (debug information format).
1578 Its .debug_names index is not yet supported.
1580 * New native configurations
1582 FreeBSD/mips mips*-*-freebsd
1586 Synopsys ARC arc*-*-elf32
1587 FreeBSD/mips mips*-*-freebsd
1589 * Removed targets and native configurations
1591 Alpha running FreeBSD alpha*-*-freebsd*
1592 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1597 Erases all the flash memory regions reported by the target.
1599 maint print arc arc-instruction address
1600 Print internal disassembler information about instruction at a given address.
1604 set disassembler-options
1605 show disassembler-options
1606 Controls the passing of target specific information to the disassembler.
1607 If it is necessary to specify more than one disassembler option then
1608 multiple options can be placed together into a comma separated list.
1609 The default value is the empty string. Currently, the only supported
1610 targets are ARM, PowerPC and S/390.
1615 Erases all the flash memory regions reported by the target. This is
1616 equivalent to the CLI command flash-erase.
1618 -file-list-shared-libraries
1619 List the shared libraries in the program. This is
1620 equivalent to the CLI command "info shared".
1623 Catchpoints stopping the program when Ada exceptions are
1624 handled. This is equivalent to the CLI command "catch handlers".
1626 *** Changes in GDB 7.12
1628 * GDB and GDBserver now build with a C++ compiler by default.
1630 The --enable-build-with-cxx configure option is now enabled by
1631 default. One must now explicitly configure with
1632 --disable-build-with-cxx in order to build with a C compiler. This
1633 option will be removed in a future release.
1635 * GDBserver now supports recording btrace without maintaining an active
1638 * GDB now supports a negative repeat count in the 'x' command to examine
1639 memory backward from the given address. For example:
1642 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1643 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1644 (gdb) x/-5i 0x0000000000400580
1645 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1646 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1647 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1648 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1649 0x40057b <main(int, char**)+25>:
1650 callq 0x400536 <Func1(int, char const*)>
1652 * Fortran: Support structures with fields of dynamic types and
1653 arrays of dynamic types.
1655 * The symbol dumping maintenance commands have new syntax.
1656 maint print symbols [-pc address] [--] [filename]
1657 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1658 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1659 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1660 maint print msymbols [-objfile objfile] [--] [filename]
1662 * GDB now supports multibit bitfields and enums in target register
1665 * New Python-based convenience function $_as_string(val), which returns
1666 the textual representation of a value. This function is especially
1667 useful to obtain the text label of an enum value.
1669 * Intel MPX bound violation handling.
1671 Segmentation faults caused by a Intel MPX boundary violation
1672 now display the kind of violation (upper or lower), the memory
1673 address accessed and the memory bounds, along with the usual
1674 signal received and code location.
1678 Program received signal SIGSEGV, Segmentation fault
1679 Upper bound violation while accessing address 0x7fffffffc3b3
1680 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1681 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1683 * Rust language support.
1684 GDB now supports debugging programs written in the Rust programming
1685 language. See https://www.rust-lang.org/ for more information about
1688 * Support for running interpreters on specified input/output devices
1690 GDB now supports a new mechanism that allows frontends to provide
1691 fully featured GDB console views, as a better alternative to
1692 building such views on top of the "-interpreter-exec console"
1693 command. See the new "new-ui" command below. With that command,
1694 frontends can now start GDB in the traditional command-line mode
1695 running in an embedded terminal emulator widget, and create a
1696 separate MI interpreter running on a specified i/o device. In this
1697 way, GDB handles line editing, history, tab completion, etc. in the
1698 console all by itself, and the GUI uses the separate MI interpreter
1699 for its own control and synchronization, invisible to the command
1702 * The "catch syscall" command catches groups of related syscalls.
1704 The "catch syscall" command now supports catching a group of related
1705 syscalls using the 'group:' or 'g:' prefix.
1710 skip -gfile file-glob-pattern
1711 skip -function function
1712 skip -rfunction regular-expression
1713 A generalized form of the skip command, with new support for
1714 glob-style file names and regular expressions for function names.
1715 Additionally, a file spec and a function spec may now be combined.
1717 maint info line-table REGEXP
1718 Display the contents of GDB's internal line table data structure.
1721 Run any GDB unit tests that were compiled in.
1724 Start a new user interface instance running INTERP as interpreter,
1725 using the TTY file for input/output.
1729 ** gdb.Breakpoint objects have a new attribute "pending", which
1730 indicates whether the breakpoint is pending.
1731 ** Three new breakpoint-related events have been added:
1732 gdb.breakpoint_created, gdb.breakpoint_modified, and
1733 gdb.breakpoint_deleted.
1735 signal-event EVENTID
1736 Signal ("set") the given MS-Windows event object. This is used in
1737 conjunction with the Windows JIT debugging (AeDebug) support, where
1738 the OS suspends a crashing process until a debugger can attach to
1739 it. Resuming the crashing process, in order to debug it, is done by
1740 signalling an event.
1742 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1743 was added in GDBserver, including JIT compiling fast tracepoint's
1744 conditional expression bytecode into native code.
1746 * Support for various remote target protocols and ROM monitors has
1749 target m32rsdi Remote M32R debugging over SDI
1750 target mips MIPS remote debugging protocol
1751 target pmon PMON ROM monitor
1752 target ddb NEC's DDB variant of PMON for Vr4300
1753 target rockhopper NEC RockHopper variant of PMON
1754 target lsi LSI variant of PMO
1756 * Support for tracepoints and fast tracepoints on powerpc-linux,
1757 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1758 including JIT compiling fast tracepoint's conditional expression
1759 bytecode into native code.
1761 * MI async record =record-started now includes the method and format used for
1762 recording. For example:
1764 =record-started,thread-group="i1",method="btrace",format="bts"
1766 * MI async record =thread-selected now includes the frame field. For example:
1768 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1772 Andes NDS32 nds32*-*-elf
1774 *** Changes in GDB 7.11
1776 * GDB now supports debugging kernel-based threads on FreeBSD.
1778 * Per-inferior thread numbers
1780 Thread numbers are now per inferior instead of global. If you're
1781 debugging multiple inferiors, GDB displays thread IDs using a
1782 qualified INF_NUM.THR_NUM form. For example:
1786 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1787 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1788 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1789 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1791 As consequence, thread numbers as visible in the $_thread
1792 convenience variable and in Python's InferiorThread.num attribute
1793 are no longer unique between inferiors.
1795 GDB now maintains a second thread ID per thread, referred to as the
1796 global thread ID, which is the new equivalent of thread numbers in
1797 previous releases. See also $_gthread below.
1799 For backwards compatibility, MI's thread IDs always refer to global
1802 * Commands that accept thread IDs now accept the qualified
1803 INF_NUM.THR_NUM form as well. For example:
1806 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1809 * In commands that accept a list of thread IDs, you can now refer to
1810 all threads of an inferior using a star wildcard. GDB accepts
1811 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1812 refer to all threads of the current inferior. For example, "info
1815 * You can use "info threads -gid" to display the global thread ID of
1818 * The new convenience variable $_gthread holds the global number of
1821 * The new convenience variable $_inferior holds the number of the
1824 * GDB now displays the ID and name of the thread that hit a breakpoint
1825 or received a signal, if your program is multi-threaded. For
1828 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1829 Thread 1 "main" received signal SIGINT, Interrupt.
1831 * Record btrace now supports non-stop mode.
1833 * Support for tracepoints on aarch64-linux was added in GDBserver.
1835 * The 'record instruction-history' command now indicates speculative execution
1836 when using the Intel Processor Trace recording format.
1838 * GDB now allows users to specify explicit locations, bypassing
1839 the linespec parser. This feature is also available to GDB/MI
1842 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1843 GDB now is able to debug both AArch64 applications and ARM applications
1846 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1847 including JIT compiling fast tracepoint's conditional expression bytecode
1850 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1852 * "info threads", "info inferiors", "info display", "info checkpoints"
1853 and "maint info program-spaces" now list the corresponding items in
1854 ascending ID order, for consistency with all other "info" commands.
1856 * In Ada, the overloads selection menu has been enhanced to display the
1857 parameter types and the return types for the matching overloaded subprograms.
1861 maint set target-non-stop (on|off|auto)
1862 maint show target-non-stop
1863 Control whether GDB targets always operate in non-stop mode even if
1864 "set non-stop" is "off". The default is "auto", meaning non-stop
1865 mode is enabled if supported by the target.
1867 maint set bfd-sharing
1868 maint show bfd-sharing
1869 Control the reuse of bfd objects.
1872 show debug bfd-cache
1873 Control display of debugging info regarding bfd caching.
1877 Control display of debugging info regarding FreeBSD threads.
1879 set remote multiprocess-extensions-packet
1880 show remote multiprocess-extensions-packet
1881 Set/show the use of the remote protocol multiprocess extensions.
1883 set remote thread-events
1884 show remote thread-events
1885 Set/show the use of thread create/exit events.
1887 set ada print-signatures on|off
1888 show ada print-signatures"
1889 Control whether parameter types and return types are displayed in overloads
1890 selection menus. It is activated (@code{on}) by default.
1894 Controls the maximum size of memory, in bytes, that GDB will
1895 allocate for value contents. Prevents incorrect programs from
1896 causing GDB to allocate overly large buffers. Default is 64k.
1898 * The "disassemble" command accepts a new modifier: /s.
1899 It prints mixed source+disassembly like /m with two differences:
1900 - disassembled instructions are now printed in program order, and
1901 - and source for all relevant files is now printed.
1902 The "/m" option is now considered deprecated: its "source-centric"
1903 output hasn't proved useful in practice.
1905 * The "record instruction-history" command accepts a new modifier: /s.
1906 It behaves exactly like /m and prints mixed source+disassembly.
1908 * The "set scheduler-locking" command supports a new mode "replay".
1909 It behaves like "off" in record mode and like "on" in replay mode.
1911 * Support for various ROM monitors has been removed:
1913 target dbug dBUG ROM monitor for Motorola ColdFire
1914 target picobug Motorola picobug monitor
1915 target dink32 DINK32 ROM monitor for PowerPC
1916 target m32r Renesas M32R/D ROM monitor
1917 target mon2000 mon2000 ROM monitor
1918 target ppcbug PPCBUG ROM monitor for PowerPC
1920 * Support for reading/writing memory and extracting values on architectures
1921 whose memory is addressable in units of any integral multiple of 8 bits.
1924 Allows to break when an Ada exception is handled.
1926 * New remote packets
1929 Indicates that an exec system call was executed.
1931 exec-events feature in qSupported
1932 The qSupported packet allows GDB to request support for exec
1933 events using the new 'gdbfeature' exec-event, and the qSupported
1934 response can contain the corresponding 'stubfeature'. Set and
1935 show commands can be used to display whether these features are enabled.
1938 Equivalent to interrupting with the ^C character, but works in
1941 thread created stop reason (T05 create:...)
1942 Indicates that the thread was just created and is stopped at entry.
1944 thread exit stop reply (w exitcode;tid)
1945 Indicates that the thread has terminated.
1948 Enables/disables thread create and exit event reporting. For
1949 example, this is used in non-stop mode when GDB stops a set of
1950 threads and synchronously waits for the their corresponding stop
1951 replies. Without exit events, if one of the threads exits, GDB
1952 would hang forever not knowing that it should no longer expect a
1953 stop for that same thread.
1956 Indicates that there are no resumed threads left in the target (all
1957 threads are stopped). The remote stub reports support for this stop
1958 reply to GDB's qSupported query.
1961 Enables/disables catching syscalls from the inferior process.
1962 The remote stub reports support for this packet to GDB's qSupported query.
1964 syscall_entry stop reason
1965 Indicates that a syscall was just called.
1967 syscall_return stop reason
1968 Indicates that a syscall just returned.
1970 * Extended-remote exec events
1972 ** GDB now has support for exec events on extended-remote Linux targets.
1973 For such targets with Linux kernels 2.5.46 and later, this enables
1974 follow-exec-mode and exec catchpoints.
1976 set remote exec-event-feature-packet
1977 show remote exec-event-feature-packet
1978 Set/show the use of the remote exec event feature.
1980 * Thread names in remote protocol
1982 The reply to qXfer:threads:read may now include a name attribute for each
1985 * Target remote mode fork and exec events
1987 ** GDB now has support for fork and exec events on target remote mode
1988 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1989 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1990 fork and exec catchpoints.
1992 * Remote syscall events
1994 ** GDB now has support for catch syscall on remote Linux targets,
1995 currently enabled on x86/x86_64 architectures.
1997 set remote catch-syscall-packet
1998 show remote catch-syscall-packet
1999 Set/show the use of the remote catch syscall feature.
2003 ** The -var-set-format command now accepts the zero-hexadecimal
2004 format. It outputs data in hexadecimal format with zero-padding on the
2009 ** gdb.InferiorThread objects have a new attribute "global_num",
2010 which refers to the thread's global thread ID. The existing
2011 "num" attribute now refers to the thread's per-inferior number.
2012 See "Per-inferior thread numbers" above.
2013 ** gdb.InferiorThread objects have a new attribute "inferior", which
2014 is the Inferior object the thread belongs to.
2016 *** Changes in GDB 7.10
2018 * Support for process record-replay and reverse debugging on aarch64*-linux*
2019 targets has been added. GDB now supports recording of A64 instruction set
2020 including advance SIMD instructions.
2022 * Support for Sun's version of the "stabs" debug file format has been removed.
2024 * GDB now honors the content of the file /proc/PID/coredump_filter
2025 (PID is the process ID) on GNU/Linux systems. This file can be used
2026 to specify the types of memory mappings that will be included in a
2027 corefile. For more information, please refer to the manual page of
2028 "core(5)". GDB also has a new command: "set use-coredump-filter
2029 on|off". It allows to set whether GDB will read the content of the
2030 /proc/PID/coredump_filter file when generating a corefile.
2032 * The "info os" command on GNU/Linux can now display information on
2034 "info os cpus" Listing of all cpus/cores on the system
2036 * GDB has two new commands: "set serial parity odd|even|none" and
2037 "show serial parity". These allows to set or show parity for the
2040 * The "info source" command now displays the producer string if it was
2041 present in the debug info. This typically includes the compiler version
2042 and may include things like its command line arguments.
2044 * The "info dll", an alias of the "info sharedlibrary" command,
2045 is now available on all platforms.
2047 * Directory names supplied to the "set sysroot" commands may be
2048 prefixed with "target:" to tell GDB to access shared libraries from
2049 the target system, be it local or remote. This replaces the prefix
2050 "remote:". The default sysroot has been changed from "" to
2051 "target:". "remote:" is automatically converted to "target:" for
2052 backward compatibility.
2054 * The system root specified by "set sysroot" will be prepended to the
2055 filename of the main executable (if reported to GDB as absolute by
2056 the operating system) when starting processes remotely, and when
2057 attaching to already-running local or remote processes.
2059 * GDB now supports automatic location and retrieval of executable
2060 files from remote targets. Remote debugging can now be initiated
2061 using only a "target remote" or "target extended-remote" command
2062 (no "set sysroot" or "file" commands are required). See "New remote
2065 * The "dump" command now supports verilog hex format.
2067 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2069 * On GNU/Linux, GDB and gdbserver are now able to access executable
2070 and shared library files without a "set sysroot" command when
2071 attaching to processes running in different mount namespaces from
2072 the debugger. This makes it possible to attach to processes in
2073 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2074 See "New remote packets" below.
2076 * The "tui reg" command now provides completion for all of the
2077 available register groups, including target specific groups.
2079 * The HISTSIZE environment variable is no longer read when determining
2080 the size of GDB's command history. GDB now instead reads the dedicated
2081 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2082 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2087 ** Memory ports can now be unbuffered.
2091 ** gdb.Objfile objects have a new attribute "username",
2092 which is the name of the objfile as specified by the user,
2093 without, for example, resolving symlinks.
2094 ** You can now write frame unwinders in Python.
2095 ** gdb.Type objects have a new method "optimized_out",
2096 returning optimized out gdb.Value instance of this type.
2097 ** gdb.Value objects have new methods "reference_value" and
2098 "const_value" which return a reference to the value and a
2099 "const" version of the value respectively.
2103 maint print symbol-cache
2104 Print the contents of the symbol cache.
2106 maint print symbol-cache-statistics
2107 Print statistics of symbol cache usage.
2109 maint flush-symbol-cache
2110 Flush the contents of the symbol cache.
2114 Start branch trace recording using Branch Trace Store (BTS) format.
2117 Evaluate expression by using the compiler and print result.
2121 Explicit commands for enabling and disabling tui mode.
2124 set mpx bound on i386 and amd64
2125 Support for bound table investigation on Intel MPX enabled applications.
2129 Start branch trace recording using Intel Processor Trace format.
2132 Print information about branch tracing internals.
2134 maint btrace packet-history
2135 Print the raw branch tracing data.
2137 maint btrace clear-packet-history
2138 Discard the stored raw branch tracing data.
2141 Discard all branch tracing data. It will be fetched and processed
2142 anew by the next "record" command.
2147 Renamed from "set debug dwarf2-die".
2148 show debug dwarf-die
2149 Renamed from "show debug dwarf2-die".
2151 set debug dwarf-read
2152 Renamed from "set debug dwarf2-read".
2153 show debug dwarf-read
2154 Renamed from "show debug dwarf2-read".
2156 maint set dwarf always-disassemble
2157 Renamed from "maint set dwarf2 always-disassemble".
2158 maint show dwarf always-disassemble
2159 Renamed from "maint show dwarf2 always-disassemble".
2161 maint set dwarf max-cache-age
2162 Renamed from "maint set dwarf2 max-cache-age".
2163 maint show dwarf max-cache-age
2164 Renamed from "maint show dwarf2 max-cache-age".
2166 set debug dwarf-line
2167 show debug dwarf-line
2168 Control display of debugging info regarding DWARF line processing.
2171 show max-completions
2172 Set the maximum number of candidates to be considered during
2173 completion. The default value is 200. This limit allows GDB
2174 to avoid generating large completion lists, the computation of
2175 which can cause the debugger to become temporarily unresponsive.
2177 set history remove-duplicates
2178 show history remove-duplicates
2179 Control the removal of duplicate history entries.
2181 maint set symbol-cache-size
2182 maint show symbol-cache-size
2183 Control the size of the symbol cache.
2185 set|show record btrace bts buffer-size
2186 Set and show the size of the ring buffer used for branch tracing in
2188 The obtained size may differ from the requested size. Use "info
2189 record" to see the obtained buffer size.
2191 set debug linux-namespaces
2192 show debug linux-namespaces
2193 Control display of debugging info regarding Linux namespaces.
2195 set|show record btrace pt buffer-size
2196 Set and show the size of the ring buffer used for branch tracing in
2197 Intel Processor Trace format.
2198 The obtained size may differ from the requested size. Use "info
2199 record" to see the obtained buffer size.
2201 maint set|show btrace pt skip-pad
2202 Set and show whether PAD packets are skipped when computing the
2205 * The command 'thread apply all' can now support new option '-ascending'
2206 to call its specified command for all threads in ascending order.
2208 * Python/Guile scripting
2210 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2211 special section named `.debug_gdb_scripts'.
2213 * New remote packets
2215 qXfer:btrace-conf:read
2216 Return the branch trace configuration for the current thread.
2218 Qbtrace-conf:bts:size
2219 Set the requested ring buffer size for branch tracing in BTS format.
2222 Enable Intel Processor Trace-based branch tracing for the current
2223 process. The remote stub reports support for this packet to GDB's
2226 Qbtrace-conf:pt:size
2227 Set the requested ring buffer size for branch tracing in Intel Processor
2231 Indicates a memory breakpoint instruction was executed, irrespective
2232 of whether it was GDB that planted the breakpoint or the breakpoint
2233 is hardcoded in the program. This is required for correct non-stop
2237 Indicates the target stopped for a hardware breakpoint. This is
2238 required for correct non-stop mode operation.
2241 Return information about files on the remote system.
2243 qXfer:exec-file:read
2244 Return the full absolute name of the file that was executed to
2245 create a process running on the remote system.
2248 Select the filesystem on which vFile: operations with filename
2249 arguments will operate. This is required for GDB to be able to
2250 access files on remote targets where the remote stub does not
2251 share a common filesystem with the inferior(s).
2254 Indicates that a fork system call was executed.
2257 Indicates that a vfork system call was executed.
2259 vforkdone stop reason
2260 Indicates that a vfork child of the specified process has executed
2261 an exec or exit, allowing the vfork parent to resume execution.
2263 fork-events and vfork-events features in qSupported
2264 The qSupported packet allows GDB to request support for fork and
2265 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2266 and the qSupported response can contain the corresponding
2267 'stubfeatures'. Set and show commands can be used to display
2268 whether these features are enabled.
2270 * Extended-remote fork events
2272 ** GDB now has support for fork events on extended-remote Linux
2273 targets. For targets with Linux kernels 2.5.60 and later, this
2274 enables follow-fork-mode and detach-on-fork for both fork and
2275 vfork, as well as fork and vfork catchpoints.
2277 * The info record command now shows the recording format and the
2278 branch tracing configuration for the current thread when using
2279 the btrace record target.
2280 For the BTS format, it shows the ring buffer size.
2282 * GDB now has support for DTrace USDT (Userland Static Defined
2283 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2285 * GDB now supports access to vector registers on S/390 GNU/Linux
2288 * Removed command line options
2290 -xdb HP-UX XDB compatibility mode.
2292 * Removed targets and native configurations
2294 HP/PA running HP-UX hppa*-*-hpux*
2295 Itanium running HP-UX ia64-*-hpux*
2297 * New configure options
2300 This configure option allows the user to build GDB with support for
2301 Intel Processor Trace (default: auto). This requires libipt.
2303 --with-libipt-prefix=PATH
2304 Specify the path to the version of libipt that GDB should use.
2305 $PATH/include should contain the intel-pt.h header and
2306 $PATH/lib should contain the libipt.so library.
2308 *** Changes in GDB 7.9.1
2312 ** Xmethods can now specify a result type.
2314 *** Changes in GDB 7.9
2316 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2320 ** You can now access frame registers from Python scripts.
2321 ** New attribute 'producer' for gdb.Symtab objects.
2322 ** gdb.Objfile objects have a new attribute "progspace",
2323 which is the gdb.Progspace object of the containing program space.
2324 ** gdb.Objfile objects have a new attribute "owner".
2325 ** gdb.Objfile objects have a new attribute "build_id",
2326 which is the build ID generated when the file was built.
2327 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2328 ** A new event "gdb.clear_objfiles" has been added, triggered when
2329 selecting a new file to debug.
2330 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2331 ** New function gdb.lookup_objfile.
2333 New events which are triggered when GDB modifies the state of the
2336 ** gdb.events.inferior_call_pre: Function call is about to be made.
2337 ** gdb.events.inferior_call_post: Function call has just been made.
2338 ** gdb.events.memory_changed: A memory location has been altered.
2339 ** gdb.events.register_changed: A register has been altered.
2341 * New Python-based convenience functions:
2343 ** $_caller_is(name [, number_of_frames])
2344 ** $_caller_matches(regexp [, number_of_frames])
2345 ** $_any_caller_is(name [, number_of_frames])
2346 ** $_any_caller_matches(regexp [, number_of_frames])
2348 * GDB now supports the compilation and injection of source code into
2349 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2350 to compile the source code to object code, and if successful, inject
2351 and execute that code within the current context of the inferior.
2352 Currently the C language is supported. The commands used to
2353 interface with this new feature are:
2355 compile code [-raw|-r] [--] [source code]
2356 compile file [-raw|-r] filename
2360 demangle [-l language] [--] name
2361 Demangle "name" in the specified language, or the current language
2362 if elided. This command is renamed from the "maint demangle" command.
2363 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2364 as "maint demangler-warning".
2366 queue-signal signal-name-or-number
2367 Queue a signal to be delivered to the thread when it is resumed.
2369 add-auto-load-scripts-directory directory
2370 Add entries to the list of directories from which to load auto-loaded
2373 maint print user-registers
2374 List all currently available "user" registers.
2376 compile code [-r|-raw] [--] [source code]
2377 Compile, inject, and execute in the inferior the executable object
2378 code produced by compiling the provided source code.
2380 compile file [-r|-raw] filename
2381 Compile and inject into the inferior the executable object code
2382 produced by compiling the source code stored in the filename
2385 * On resume, GDB now always passes the signal the program had stopped
2386 for to the thread the signal was sent to, even if the user changed
2387 threads before resuming. Previously GDB would often (but not
2388 always) deliver the signal to the thread that happens to be current
2391 * Conversely, the "signal" command now consistently delivers the
2392 requested signal to the current thread. GDB now asks for
2393 confirmation if the program had stopped for a signal and the user
2394 switched threads meanwhile.
2396 * "breakpoint always-inserted" modes "off" and "auto" merged.
2398 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2399 won't remove breakpoints from the target until all threads stop,
2400 even in non-stop mode. The "auto" mode has been removed, and "off"
2401 is now the default mode.
2405 set debug symbol-lookup
2406 show debug symbol-lookup
2407 Control display of debugging info regarding symbol lookup.
2411 ** The -list-thread-groups command outputs an exit-code field for
2412 inferiors that have exited.
2416 MIPS SDE mips*-sde*-elf*
2420 Support for these obsolete configurations has been removed.
2422 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2423 SGI Irix-5.x mips-*-irix5*
2424 SGI Irix-6.x mips-*-irix6*
2425 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2426 VAX running Ultrix vax-*-ultrix*
2428 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2429 and "assf"), have been removed. Use the "sharedlibrary" command, or
2430 its alias "share", instead.
2432 *** Changes in GDB 7.8
2434 * New command line options
2437 This is an alias for the --data-directory option.
2439 * GDB supports printing and modifying of variable length automatic arrays
2440 as specified in ISO C99.
2442 * The ARM simulator now supports instruction level tracing
2443 with or without disassembly.
2447 GDB now has support for scripting using Guile. Whether this is
2448 available is determined at configure time.
2449 Guile version 2.0 or greater is required.
2450 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2452 * New commands (for set/show, see "New options" below)
2456 Invoke CODE by passing it to the Guile interpreter.
2460 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2462 info auto-load guile-scripts [regexp]
2463 Print the list of automatically loaded Guile scripts.
2465 * The source command is now capable of sourcing Guile scripts.
2466 This feature is dependent on the debugger being built with Guile support.
2470 set print symbol-loading (off|brief|full)
2471 show print symbol-loading
2472 Control whether to print informational messages when loading symbol
2473 information for a file. The default is "full", but when debugging
2474 programs with large numbers of shared libraries the amount of output
2475 becomes less useful.
2477 set guile print-stack (none|message|full)
2478 show guile print-stack
2479 Show a stack trace when an error is encountered in a Guile script.
2481 set auto-load guile-scripts (on|off)
2482 show auto-load guile-scripts
2483 Control auto-loading of Guile script files.
2485 maint ada set ignore-descriptive-types (on|off)
2486 maint ada show ignore-descriptive-types
2487 Control whether the debugger should ignore descriptive types in Ada
2488 programs. The default is not to ignore the descriptive types. See
2489 the user manual for more details on descriptive types and the intended
2490 usage of this option.
2492 set auto-connect-native-target
2494 Control whether GDB is allowed to automatically connect to the
2495 native target for the run, attach, etc. commands when not connected
2496 to any target yet. See also "target native" below.
2498 set record btrace replay-memory-access (read-only|read-write)
2499 show record btrace replay-memory-access
2500 Control what memory accesses are allowed during replay.
2502 maint set target-async (on|off)
2503 maint show target-async
2504 This controls whether GDB targets operate in synchronous or
2505 asynchronous mode. Normally the default is asynchronous, if it is
2506 available; but this can be changed to more easily debug problems
2507 occurring only in synchronous mode.
2509 set mi-async (on|off)
2511 Control whether MI asynchronous mode is preferred. This supersedes
2512 "set target-async" of previous GDB versions.
2514 * "set target-async" is deprecated as a CLI option and is now an alias
2515 for "set mi-async" (only puts MI into async mode).
2517 * Background execution commands (e.g., "c&", "s&", etc.) are now
2518 possible ``out of the box'' if the target supports them. Previously
2519 the user would need to explicitly enable the possibility with the
2520 "set target-async on" command.
2522 * New features in the GDB remote stub, GDBserver
2524 ** New option --debug-format=option1[,option2,...] allows one to add
2525 additional text to each output. At present only timestamps
2526 are supported: --debug-format=timestamps.
2527 Timestamps can also be turned on with the
2528 "monitor set debug-format timestamps" command from GDB.
2530 * The 'record instruction-history' command now starts counting instructions
2531 at one. This also affects the instruction ranges reported by the
2532 'record function-call-history' command when given the /i modifier.
2534 * The command 'record function-call-history' supports a new modifier '/c' to
2535 indent the function names based on their call stack depth.
2536 The fields for the '/i' and '/l' modifier have been reordered.
2537 The source line range is now prefixed with 'at'.
2538 The instruction range is now prefixed with 'inst'.
2539 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2540 "record instruction-history" and "list" commands.
2542 * The ranges given as arguments to the 'record function-call-history' and
2543 'record instruction-history' commands are now inclusive.
2545 * The btrace record target now supports the 'record goto' command.
2546 For locations inside the execution trace, the back trace is computed
2547 based on the information stored in the execution trace.
2549 * The btrace record target supports limited reverse execution and replay.
2550 The target does not record data and therefore does not allow reading
2551 memory or registers.
2553 * The "catch syscall" command now works on s390*-linux* targets.
2555 * The "compare-sections" command is no longer specific to target
2556 remote. It now works with all targets.
2558 * All native targets are now consistently called "native".
2559 Consequently, the "target child", "target GNU", "target djgpp",
2560 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2561 commands have been replaced with "target native". The QNX/NTO port
2562 leaves the "procfs" target in place and adds a "native" target for
2563 consistency with other ports. The impact on users should be minimal
2564 as these commands previously either throwed an error, or were
2565 no-ops. The target's name is visible in the output of the following
2566 commands: "help target", "info target", "info files", "maint print
2569 * The "target native" command now connects to the native target. This
2570 can be used to launch native programs even when "set
2571 auto-connect-native-target" is set to off.
2573 * GDB now supports access to Intel MPX registers on GNU/Linux.
2575 * Support for Intel AVX-512 registers on GNU/Linux.
2576 Support displaying and modifying Intel AVX-512 registers
2577 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2579 * New remote packets
2581 qXfer:btrace:read's annex
2582 The qXfer:btrace:read packet supports a new annex 'delta' to read
2583 branch trace incrementally.
2587 ** Valid Python operations on gdb.Value objects representing
2588 structs/classes invoke the corresponding overloaded operators if
2590 ** New `Xmethods' feature in the Python API. Xmethods are
2591 additional methods or replacements for existing methods of a C++
2592 class. This feature is useful for those cases where a method
2593 defined in C++ source code could be inlined or optimized out by
2594 the compiler, making it unavailable to GDB.
2597 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2599 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2600 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2601 its alias "share", instead.
2603 * The commands "set remotebaud" and "show remotebaud" are no longer
2604 supported. Use "set serial baud" and "show serial baud" (respectively)
2609 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2610 target-async". The latter is left as a deprecated alias of the
2611 former for backward compatibility. If the target supports it,
2612 CLI background execution commands are now always possible by
2613 default, independently of whether the frontend stated a
2614 preference for asynchronous execution with "-gdb-set mi-async".
2615 Previously "-gdb-set target-async off" affected both MI execution
2616 commands and CLI execution commands.
2618 *** Changes in GDB 7.7
2620 * Improved support for process record-replay and reverse debugging on
2621 arm*-linux* targets. Support for thumb32 and syscall instruction
2622 recording has been added.
2624 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2626 * GDB now supports Fission DWP file format version 2.
2627 http://gcc.gnu.org/wiki/DebugFission
2629 * New convenience function "$_isvoid", to check whether an expression
2630 is void. A void expression is an expression where the type of the
2631 result is "void". For example, some convenience variables may be
2632 "void" when evaluated (e.g., "$_exitcode" before the execution of
2633 the program being debugged; or an undefined convenience variable).
2634 Another example, when calling a function whose return type is
2637 * The "maintenance print objfiles" command now takes an optional regexp.
2639 * The "catch syscall" command now works on arm*-linux* targets.
2641 * GDB now consistently shows "<not saved>" when printing values of
2642 registers the debug info indicates have not been saved in the frame
2643 and there's nowhere to retrieve them from
2644 (callee-saved/call-clobbered registers):
2649 (gdb) info registers rax
2652 Before, the former would print "<optimized out>", and the latter
2653 "*value not available*".
2655 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2660 ** Frame filters and frame decorators have been added.
2661 ** Temporary breakpoints are now supported.
2662 ** Line tables representation has been added.
2663 ** New attribute 'parent_type' for gdb.Field objects.
2664 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2665 ** New attribute 'name' for gdb.Type objects.
2669 Nios II ELF nios2*-*-elf
2670 Nios II GNU/Linux nios2*-*-linux
2671 Texas Instruments MSP430 msp430*-*-elf
2673 * Removed native configurations
2675 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2676 been removed. ELF variants of these configurations are kept supported.
2678 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2679 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2680 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2681 i[34567]86-*-openbsd3.[0-3]
2682 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2683 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2684 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2688 Like "catch throw", but catches a re-thrown exception.
2689 maint check-psymtabs
2690 Renamed from old "maint check-symtabs".
2692 Perform consistency checks on symtabs.
2693 maint expand-symtabs
2694 Expand symtabs matching an optional regexp.
2697 Display the details of GDB configure-time options.
2699 maint set|show per-command
2700 maint set|show per-command space
2701 maint set|show per-command time
2702 maint set|show per-command symtab
2703 Enable display of per-command gdb resource usage.
2705 remove-symbol-file FILENAME
2706 remove-symbol-file -a ADDRESS
2707 Remove a symbol file added via add-symbol-file. The file to remove
2708 can be identified by its filename or by an address that lies within
2709 the boundaries of this symbol file in memory.
2712 info exceptions REGEXP
2713 Display the list of Ada exceptions defined in the program being
2714 debugged. If provided, only the exceptions whose names match REGEXP
2719 set debug symfile off|on
2721 Control display of debugging info regarding reading symbol files and
2722 symbol tables within those files
2724 set print raw frame-arguments
2725 show print raw frame-arguments
2726 Set/show whether to print frame arguments in raw mode,
2727 disregarding any defined pretty-printers.
2729 set remote trace-status-packet
2730 show remote trace-status-packet
2731 Set/show the use of remote protocol qTStatus packet.
2735 Control display of debugging messages related to Nios II targets.
2739 Control whether target-assisted range stepping is enabled.
2741 set startup-with-shell
2742 show startup-with-shell
2743 Specifies whether Unix child processes are started via a shell or
2748 Use the target memory cache for accesses to the code segment. This
2749 improves performance of remote debugging (particularly disassembly).
2751 * You can now use a literal value 'unlimited' for options that
2752 interpret 0 or -1 as meaning "unlimited". E.g., "set
2753 trace-buffer-size unlimited" is now an alias for "set
2754 trace-buffer-size -1" and "set height unlimited" is now an alias for
2757 * The "set debug symtab-create" debugging option of GDB has been changed to
2758 accept a verbosity level. 0 means "off", 1 provides basic debugging
2759 output, and values of 2 or greater provides more verbose output.
2761 * New command-line options
2763 Display the details of GDB configure-time options.
2765 * The command 'tsave' can now support new option '-ctf' to save trace
2766 buffer in Common Trace Format.
2768 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2771 * GDB now implements the C++ 'typeid' operator.
2773 * The new convenience variable $_exception holds the exception being
2774 thrown or caught at an exception-related catchpoint.
2776 * The exception-related catchpoints, like "catch throw", now accept a
2777 regular expression which can be used to filter exceptions by type.
2779 * The new convenience variable $_exitsignal is automatically set to
2780 the terminating signal number when the program being debugged dies
2781 due to an uncaught signal.
2785 ** All MI commands now accept an optional "--language" option.
2786 Support for this feature can be verified by using the "-list-features"
2787 command, which should contain "language-option".
2789 ** The new command -info-gdb-mi-command allows the user to determine
2790 whether a GDB/MI command is supported or not.
2792 ** The "^error" result record returned when trying to execute an undefined
2793 GDB/MI command now provides a variable named "code" whose content is the
2794 "undefined-command" error code. Support for this feature can be verified
2795 by using the "-list-features" command, which should contain
2796 "undefined-command-error-code".
2798 ** The -trace-save MI command can optionally save trace buffer in Common
2801 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2803 ** The command -data-list-register-values now accepts an optional
2804 "--skip-unavailable" option. When used, only the available registers
2807 ** The new command -trace-frame-collected dumps collected variables,
2808 computed expressions, tvars, memory and registers in a traceframe.
2810 ** The commands -stack-list-locals, -stack-list-arguments and
2811 -stack-list-variables now accept an option "--skip-unavailable".
2812 When used, only the available locals or arguments are displayed.
2814 ** The -exec-run command now accepts an optional "--start" option.
2815 When used, the command follows the same semantics as the "start"
2816 command, stopping the program's execution at the start of its
2817 main subprogram. Support for this feature can be verified using
2818 the "-list-features" command, which should contain
2819 "exec-run-start-option".
2821 ** The new commands -catch-assert and -catch-exceptions insert
2822 catchpoints stopping the program when Ada exceptions are raised.
2824 ** The new command -info-ada-exceptions provides the equivalent of
2825 the new "info exceptions" command.
2827 * New system-wide configuration scripts
2828 A GDB installation now provides scripts suitable for use as system-wide
2829 configuration scripts for the following systems:
2833 * GDB now supports target-assigned range stepping with remote targets.
2834 This improves the performance of stepping source lines by reducing
2835 the number of control packets from/to GDB. See "New remote packets"
2838 * GDB now understands the element 'tvar' in the XML traceframe info.
2839 It has the id of the collected trace state variables.
2841 * On S/390 targets that provide the transactional-execution feature,
2842 the program interruption transaction diagnostic block (TDB) is now
2843 represented as a number of additional "registers" in GDB.
2845 * New remote packets
2849 The vCont packet supports a new 'r' action, that tells the remote
2850 stub to step through an address range itself, without GDB
2851 involvemement at each single-step.
2853 qXfer:libraries-svr4:read's annex
2854 The previously unused annex of the qXfer:libraries-svr4:read packet
2855 is now used to support passing an argument list. The remote stub
2856 reports support for this argument list to GDB's qSupported query.
2857 The defined arguments are "start" and "prev", used to reduce work
2858 necessary for library list updating, resulting in significant
2861 * New features in the GDB remote stub, GDBserver
2863 ** GDBserver now supports target-assisted range stepping. Currently
2864 enabled on x86/x86_64 GNU/Linux targets.
2866 ** GDBserver now adds element 'tvar' in the XML in the reply to
2867 'qXfer:traceframe-info:read'. It has the id of the collected
2868 trace state variables.
2870 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2873 * New 'z' formatter for printing and examining memory, this displays the
2874 value as hexadecimal zero padded on the left to the size of the type.
2876 * GDB can now use Windows x64 unwinding data.
2878 * The "set remotebaud" command has been replaced by "set serial baud".
2879 Similarly, "show remotebaud" has been replaced by "show serial baud".
2880 The "set remotebaud" and "show remotebaud" commands are still available
2881 to provide backward compatibility with older versions of GDB.
2883 *** Changes in GDB 7.6
2885 * Target record has been renamed to record-full.
2886 Record/replay is now enabled with the "record full" command.
2887 This also affects settings that are associated with full record/replay
2888 that have been moved from "set/show record" to "set/show record full":
2890 set|show record full insn-number-max
2891 set|show record full stop-at-limit
2892 set|show record full memory-query
2894 * A new record target "record-btrace" has been added. The new target
2895 uses hardware support to record the control-flow of a process. It
2896 does not support replaying the execution, but it implements the
2897 below new commands for investigating the recorded execution log.
2898 This new recording method can be enabled using:
2902 The "record-btrace" target is only available on Intel Atom processors
2903 and requires a Linux kernel 2.6.32 or later.
2905 * Two new commands have been added for record/replay to give information
2906 about the recorded execution without having to replay the execution.
2907 The commands are only supported by "record btrace".
2909 record instruction-history prints the execution history at
2910 instruction granularity
2912 record function-call-history prints the execution history at
2913 function granularity
2915 * New native configurations
2917 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
2918 FreeBSD/powerpc powerpc*-*-freebsd
2919 x86_64/Cygwin x86_64-*-cygwin*
2920 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
2924 ARM AArch64 aarch64*-*-elf
2925 ARM AArch64 GNU/Linux aarch64*-*-linux
2926 Lynx 178 PowerPC powerpc-*-lynx*178
2927 x86_64/Cygwin x86_64-*-cygwin*
2928 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2930 * If the configured location of system.gdbinit file (as given by the
2931 --with-system-gdbinit option at configure time) is in the
2932 data-directory (as specified by --with-gdb-datadir at configure
2933 time) or in one of its subdirectories, then GDB will look for the
2934 system-wide init file in the directory specified by the
2935 --data-directory command-line option.
2937 * New command line options:
2939 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2940 other initialization files, unlike -nx which disables all of them.
2942 * Removed command line options
2944 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2947 * The 'ptype' and 'whatis' commands now accept an argument to control
2950 * 'info proc' now works on some core files.
2954 ** Vectors can be created with gdb.Type.vector.
2956 ** Python's atexit.register now works in GDB.
2958 ** Types can be pretty-printed via a Python API.
2960 ** Python 3 is now supported (in addition to Python 2.4 or later)
2962 ** New class gdb.Architecture exposes GDB's internal representation
2963 of architecture in the Python API.
2965 ** New method Frame.architecture returns the gdb.Architecture object
2966 corresponding to the frame's architecture.
2968 * New Python-based convenience functions:
2970 ** $_memeq(buf1, buf2, length)
2971 ** $_streq(str1, str2)
2973 ** $_regex(str, regex)
2975 * The 'cd' command now defaults to using '~' (the home directory) if not
2978 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2979 default for GCC since November 2000.
2981 * The command 'forward-search' can now be abbreviated as 'fo'.
2983 * The command 'info tracepoints' can now display 'installed on target'
2984 or 'not installed on target' for each non-pending location of tracepoint.
2986 * New configure options
2988 --enable-libmcheck/--disable-libmcheck
2989 By default, development versions are built with -lmcheck on hosts
2990 that support it, in order to help track memory corruption issues.
2991 Release versions, on the other hand, are built without -lmcheck
2992 by default. The --enable-libmcheck/--disable-libmcheck configure
2993 options allow the user to override that default.
2994 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2995 This configure option allows the user to build GDB with
2996 libbabeltrace using which GDB can read Common Trace Format data.
2998 * New commands (for set/show, see "New options" below)
3001 Catch signals. This is similar to "handle", but allows commands and
3002 conditions to be attached.
3005 List the BFDs known to GDB.
3007 python-interactive [command]
3009 Start a Python interactive prompt, or evaluate the optional command
3010 and print the result of expressions.
3013 "py" is a new alias for "python".
3015 enable type-printer [name]...
3016 disable type-printer [name]...
3017 Enable or disable type printers.
3021 ** For the Renesas Super-H architecture, the "regs" command has been removed
3022 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3027 set print type methods (on|off)
3028 show print type methods
3029 Control whether method declarations are displayed by "ptype".
3030 The default is to show them.
3032 set print type typedefs (on|off)
3033 show print type typedefs
3034 Control whether typedef definitions are displayed by "ptype".
3035 The default is to show them.
3037 set filename-display basename|relative|absolute
3038 show filename-display
3039 Control the way in which filenames is displayed.
3040 The default is "relative", which preserves previous behavior.
3042 set trace-buffer-size
3043 show trace-buffer-size
3044 Request target to change the size of trace buffer.
3046 set remote trace-buffer-size-packet auto|on|off
3047 show remote trace-buffer-size-packet
3048 Control the use of the remote protocol `QTBuffer:size' packet.
3052 Control display of debugging messages related to ARM AArch64.
3055 set debug coff-pe-read
3056 show debug coff-pe-read
3057 Control display of debugging messages related to reading of COFF/PE
3062 Control display of debugging messages related to Mach-O symbols
3065 set debug notification
3066 show debug notification
3067 Control display of debugging info for async remote notification.
3071 ** Command parameter changes are now notified using new async record
3072 "=cmd-param-changed".
3073 ** Trace frame changes caused by command "tfind" are now notified using
3074 new async record "=traceframe-changed".
3075 ** The creation, deletion and modification of trace state variables
3076 are now notified using new async records "=tsv-created",
3077 "=tsv-deleted" and "=tsv-modified".
3078 ** The start and stop of process record are now notified using new
3079 async record "=record-started" and "=record-stopped".
3080 ** Memory changes are now notified using new async record
3082 ** The data-disassemble command response will include a "fullname" field
3083 containing the absolute file name when source has been requested.
3084 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3085 command, to allow pattern filling of memory areas.
3086 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3087 library load/unload events.
3088 ** The response to breakpoint commands and breakpoint async records
3089 includes an "installed" field containing a boolean state about each
3090 non-pending tracepoint location is whether installed on target or not.
3091 ** Output of the "-trace-status" command includes a "trace-file" field
3092 containing the name of the trace file being examined. This field is
3093 optional, and only present when examining a trace file.
3094 ** The "fullname" field is now always present along with the "file" field,
3095 even if the file cannot be found by GDB.
3097 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3098 You must have the LZMA library available when configuring GDB for this
3099 feature to be enabled. For more information, see:
3100 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3102 * New remote packets
3105 Set the size of trace buffer. The remote stub reports support for this
3106 packet to gdb's qSupported query.
3109 Enable Branch Trace Store (BTS)-based branch tracing for the current
3110 thread. The remote stub reports support for this packet to gdb's
3114 Disable branch tracing for the current thread. The remote stub reports
3115 support for this packet to gdb's qSupported query.
3118 Read the traced branches for the current thread. The remote stub
3119 reports support for this packet to gdb's qSupported query.
3121 *** Changes in GDB 7.5
3123 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3124 for more x32 ABI info.
3126 * GDB now supports access to MIPS DSP registers on Linux targets.
3128 * GDB now supports debugging microMIPS binaries.
3130 * The "info os" command on GNU/Linux can now display information on
3131 several new classes of objects managed by the operating system:
3132 "info os procgroups" lists process groups
3133 "info os files" lists file descriptors
3134 "info os sockets" lists internet-domain sockets
3135 "info os shm" lists shared-memory regions
3136 "info os semaphores" lists semaphores
3137 "info os msg" lists message queues
3138 "info os modules" lists loaded kernel modules
3140 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3141 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3142 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3143 options and inspect the probe arguments using the new $_probe_arg family
3144 of convenience variables. You can obtain more information about SystemTap
3145 in <http://sourceware.org/systemtap/>.
3147 * GDB now supports reversible debugging on ARM, it allows you to
3148 debug basic ARM and THUMB instructions, and provides
3149 record/replay support.
3151 * The option "symbol-reloading" has been deleted as it is no longer used.
3155 ** GDB commands implemented in Python can now be put in command class
3158 ** The "maint set python print-stack on|off" is now deleted.
3160 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3161 apply "flag enum"-style pretty-printing to any enum.
3163 ** gdb.lookup_symbol can now work when there is no current frame.
3165 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3166 the source at which the symbol was defined.
3168 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3169 method 'value'. The former indicates whether the symbol needs a
3170 frame in order to compute its value, and the latter computes the
3173 ** A new method 'referenced_value' on gdb.Value objects which can
3174 dereference pointer as well as C++ reference values.
3176 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3177 which return the global and static blocks (as gdb.Block objects),
3178 of the underlying symbol table, respectively.
3180 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3181 object associated with a PC value.
3183 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3184 of the address range occupied by code for the current source line.
3186 * Go language support.
3187 GDB now supports debugging programs written in the Go programming
3190 * GDBserver now supports stdio connections.
3191 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3193 * The binary "gdbtui" can no longer be built or installed.
3194 Use "gdb -tui" instead.
3196 * GDB will now print "flag" enums specially. A flag enum is one where
3197 all the enumerator values have no bits in common when pairwise
3198 "and"ed. When printing a value whose type is a flag enum, GDB will
3199 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3200 (gdb) print (enum E) 3
3203 * The filename part of a linespec will now match trailing components
3204 of a source file name. For example, "break gcc/expr.c:1000" will
3205 now set a breakpoint in build/gcc/expr.c, but not
3206 build/libcpp/expr.c.
3208 * The "info proc" and "generate-core-file" commands will now also
3209 work on remote targets connected to GDBserver on Linux.
3211 * The command "info catch" has been removed. It has been disabled
3212 since December 2007.
3214 * The "catch exception" and "catch assert" commands now accept
3215 a condition at the end of the command, much like the "break"
3216 command does. For instance:
3218 (gdb) catch exception Constraint_Error if Barrier = True
3220 Previously, it was possible to add a condition to such catchpoints,
3221 but it had to be done as a second step, after the catchpoint had been
3222 created, using the "condition" command.
3224 * The "info static-tracepoint-marker" command will now also work on
3225 native Linux targets with in-process agent.
3227 * GDB can now set breakpoints on inlined functions.
3229 * The .gdb_index section has been updated to include symbols for
3230 inlined functions. GDB will ignore older .gdb_index sections by
3231 default, which could cause symbol files to be loaded more slowly
3232 until their .gdb_index sections can be recreated. The new command
3233 "set use-deprecated-index-sections on" will cause GDB to use any older
3234 .gdb_index sections it finds. This will restore performance, but the
3235 ability to set breakpoints on inlined functions will be lost in symbol
3236 files with older .gdb_index sections.
3238 The .gdb_index section has also been updated to record more information
3239 about each symbol. This speeds up the "info variables", "info functions"
3240 and "info types" commands when used with programs having the .gdb_index
3241 section, as well as speeding up debugging with shared libraries using
3242 the .gdb_index section.
3244 * Ada support for GDB/MI Variable Objects has been added.
3246 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3251 ** New command -info-os is the MI equivalent of "info os".
3253 ** Output logs ("set logging" and related) now include MI output.
3257 ** "set use-deprecated-index-sections on|off"
3258 "show use-deprecated-index-sections on|off"
3259 Controls the use of deprecated .gdb_index sections.
3261 ** "catch load" and "catch unload" can be used to stop when a shared
3262 library is loaded or unloaded, respectively.
3264 ** "enable count" can be used to auto-disable a breakpoint after
3267 ** "info vtbl" can be used to show the virtual method tables for
3268 C++ and Java objects.
3270 ** "explore" and its sub commands "explore value" and "explore type"
3271 can be used to recursively explore values and types of
3272 expressions. These commands are available only if GDB is
3273 configured with '--with-python'.
3275 ** "info auto-load" shows status of all kinds of auto-loaded files,
3276 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3277 sequences of commands files, "info auto-load python-scripts"
3278 shows status of auto-loading Python script files,
3279 "info auto-load local-gdbinit" shows status of loading init file
3280 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3281 status of inferior specific thread debugging shared library loading.
3283 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3284 and "show auto-load-scripts" commands have been deprecated, use their
3285 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3286 and "show auto-load python-scripts" counterparts instead.
3288 ** "dprintf location,format,args..." creates a dynamic printf, which
3289 is basically a breakpoint that does a printf and immediately
3290 resumes your program's execution, so it is like a printf that you
3291 can insert dynamically at runtime instead of at compiletime.
3293 ** "set print symbol"
3295 Controls whether GDB attempts to display the symbol, if any,
3296 corresponding to addresses it prints. This defaults to "on", but
3297 you can set it to "off" to restore GDB's previous behavior.
3299 * Deprecated commands
3301 ** For the Renesas Super-H architecture, the "regs" command has been
3302 deprecated, and "info all-registers" should be used instead.
3306 Renesas RL78 rl78-*-elf
3307 HP OpenVMS ia64 ia64-hp-openvms*
3309 * GDBserver supports evaluation of breakpoint conditions. When
3310 support is advertised by GDBserver, GDB may be told to send the
3311 breakpoint conditions in bytecode form to GDBserver. GDBserver
3312 will only report the breakpoint trigger to GDB when its condition
3317 set mips compression
3318 show mips compression
3319 Select the compressed ISA encoding used in functions that have no symbol
3320 information available. The encoding can be set to either of:
3323 and is updated automatically from ELF file flags if available.
3325 set breakpoint condition-evaluation
3326 show breakpoint condition-evaluation
3327 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3328 GDBserver ("target"). Default option "auto" chooses the most efficient
3330 This option can improve debugger efficiency depending on the speed of the
3334 Disable auto-loading globally.
3337 Show auto-loading setting of all kinds of auto-loaded files.
3339 set auto-load gdb-scripts on|off
3340 show auto-load gdb-scripts
3341 Control auto-loading of GDB canned sequences of commands files.
3343 set auto-load python-scripts on|off
3344 show auto-load python-scripts
3345 Control auto-loading of Python script files.
3347 set auto-load local-gdbinit on|off
3348 show auto-load local-gdbinit
3349 Control loading of init file (.gdbinit) from current directory.
3351 set auto-load libthread-db on|off
3352 show auto-load libthread-db
3353 Control auto-loading of inferior specific thread debugging shared library.
3355 set auto-load scripts-directory <dir1>[:<dir2>...]
3356 show auto-load scripts-directory
3357 Set a list of directories from which to load auto-loaded scripts.
3358 Automatically loaded Python scripts and GDB scripts are located in one
3359 of the directories listed by this option.
3360 The delimiter (':' above) may differ according to the host platform.
3362 set auto-load safe-path <dir1>[:<dir2>...]
3363 show auto-load safe-path
3364 Set a list of directories from which it is safe to auto-load files.
3365 The delimiter (':' above) may differ according to the host platform.
3367 set debug auto-load on|off
3368 show debug auto-load
3369 Control display of debugging info for auto-loading the files above.
3371 set dprintf-style gdb|call|agent
3373 Control the way in which a dynamic printf is performed; "gdb"
3374 requests a GDB printf command, while "call" causes dprintf to call a
3375 function in the inferior. "agent" requests that the target agent
3376 (such as GDBserver) do the printing.
3378 set dprintf-function <expr>
3379 show dprintf-function
3380 set dprintf-channel <expr>
3381 show dprintf-channel
3382 Set the function and optional first argument to the call when using
3383 the "call" style of dynamic printf.
3385 set disconnected-dprintf on|off
3386 show disconnected-dprintf
3387 Control whether agent-style dynamic printfs continue to be in effect
3388 after GDB disconnects.
3390 * New configure options
3392 --with-auto-load-dir
3393 Configure default value for the 'set auto-load scripts-directory'
3394 setting above. It defaults to '$debugdir:$datadir/auto-load',
3395 $debugdir representing global debugging info directories (available
3396 via 'show debug-file-directory') and $datadir representing GDB's data
3397 directory (available via 'show data-directory').
3399 --with-auto-load-safe-path
3400 Configure default value for the 'set auto-load safe-path' setting
3401 above. It defaults to the --with-auto-load-dir setting.
3403 --without-auto-load-safe-path
3404 Set 'set auto-load safe-path' to '/', effectively disabling this
3407 * New remote packets
3409 z0/z1 conditional breakpoints extension
3411 The z0/z1 breakpoint insertion packets have been extended to carry
3412 a list of conditional expressions over to the remote stub depending on the
3413 condition evaluation mode. The use of this extension can be controlled
3414 via the "set remote conditional-breakpoints-packet" command.
3418 Specify the signals which the remote stub may pass to the debugged
3419 program without GDB involvement.
3421 * New command line options
3423 --init-command=FILE, -ix Like --command, -x but execute it
3424 before loading inferior.
3425 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3426 execute it before loading inferior.
3428 *** Changes in GDB 7.4
3430 * GDB now handles ambiguous linespecs more consistently; the existing
3431 FILE:LINE support has been expanded to other types of linespecs. A
3432 breakpoint will now be set on all matching locations in all
3433 inferiors, and locations will be added or removed according to
3436 * GDB now allows you to skip uninteresting functions and files when
3437 stepping with the "skip function" and "skip file" commands.
3439 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3440 and "show remote hardware-watchpoint-length-limit". These allows to
3441 set or show the maximum length limit (in bytes) of a remote
3442 target hardware watchpoint.
3444 This allows e.g. to use "unlimited" hardware watchpoints with the
3445 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3446 watchpoints are slower than real hardware watchpoints but are
3447 significantly faster than gdb software watchpoints.
3451 ** The register_pretty_printer function in module gdb.printing now takes
3452 an optional `replace' argument. If True, the new printer replaces any
3455 ** The "maint set python print-stack on|off" command has been
3456 deprecated and will be deleted in GDB 7.5.
3457 A new command: "set python print-stack none|full|message" has
3458 replaced it. Additionally, the default for "print-stack" is
3459 now "message", which just prints the error message without
3462 ** A prompt substitution hook (prompt_hook) is now available to the
3465 ** A new Python module, gdb.prompt has been added to the GDB Python
3466 modules library. This module provides functionality for
3467 escape sequences in prompts (used by set/show
3468 extended-prompt). These escape sequences are replaced by their
3469 corresponding value.
3471 ** Python commands and convenience-functions located in
3472 'data-directory'/python/gdb/command and
3473 'data-directory'/python/gdb/function are now automatically loaded
3476 ** Blocks now provide four new attributes. global_block and
3477 static_block will return the global and static blocks
3478 respectively. is_static and is_global are boolean attributes
3479 that indicate if the block is one of those two types.
3481 ** Symbols now provide the "type" attribute, the type of the symbol.
3483 ** The "gdb.breakpoint" function has been deprecated in favor of
3486 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3487 of a function. This class is based on the "finish" command
3488 available in the CLI.
3490 ** Type objects for struct and union types now allow access to
3491 the fields using standard Python dictionary (mapping) methods.
3492 For example, "some_type['myfield']" now works, as does
3493 "some_type.items()".
3495 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3498 ** A new function, "deep_items" has been added to the gdb.types
3499 module in the GDB Python modules library. This function returns
3500 an iterator over the fields of a struct or union type. Unlike
3501 the standard Python "iteritems" method, it will recursively traverse
3502 any anonymous fields.
3506 ** "*stopped" events can report several new "reason"s, such as
3509 ** Breakpoint changes are now notified using new async records, like
3510 "=breakpoint-modified".
3512 ** New command -ada-task-info.
3514 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3515 $sdir specifies the default system locations of shared libraries.
3516 $pdir specifies the directory where the libpthread used by the application
3519 GDB no longer looks in $sdir and $pdir after it has searched the directories
3520 mentioned in libthread-db-search-path. If you want to search those
3521 directories, they must be specified in libthread-db-search-path.
3522 The default value of libthread-db-search-path on GNU/Linux and Solaris
3523 systems is now "$sdir:$pdir".
3525 $pdir is not supported by gdbserver, it is currently ignored.
3526 $sdir is supported by gdbserver.
3528 * New configure option --with-iconv-bin.
3529 When using the internationalization support like the one in the GNU C
3530 library, GDB will invoke the "iconv" program to get a list of supported
3531 character sets. If this program lives in a non-standard location, one can
3532 use this option to specify where to find it.
3534 * When natively debugging programs on PowerPC BookE processors running
3535 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3536 watchpoints, which specify a mask in addition to an address to watch.
3537 The mask specifies that some bits of an address (the bits which are
3538 reset in the mask) should be ignored when matching the address accessed
3539 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3540 section in the user manual for more details.
3542 * The new option --once causes GDBserver to stop listening for connections once
3543 the first connection is made. The listening port used by GDBserver will
3544 become available after that.
3546 * New commands "info macros" and "alias" have been added.
3548 * New function parameters suffix @entry specifies value of function parameter
3549 at the time the function got called. Entry values are available only since
3555 "!" is now an alias of the "shell" command.
3556 Note that no space is needed between "!" and SHELL COMMAND.
3560 watch EXPRESSION mask MASK_VALUE
3561 The watch command now supports the mask argument which allows creation
3562 of masked watchpoints, if the current architecture supports this feature.
3564 info auto-load-scripts [REGEXP]
3565 This command was formerly named "maintenance print section-scripts".
3566 It is now generally useful and is no longer a maintenance-only command.
3568 info macro [-all] [--] MACRO
3569 The info macro command has new options `-all' and `--'. The first for
3570 printing all definitions of a macro. The second for explicitly specifying
3571 the end of arguments and the beginning of the macro name in case the macro
3572 name starts with a hyphen.
3574 collect[/s] EXPRESSIONS
3575 The tracepoint collect command now takes an optional modifier "/s"
3576 that directs it to dereference pointer-to-character types and
3577 collect the bytes of memory up to a zero byte. The behavior is
3578 similar to what you see when you use the regular print command on a
3579 string. An optional integer following the "/s" sets a bound on the
3580 number of bytes that will be collected.
3583 The trace start command now interprets any supplied arguments as a
3584 note to be recorded with the trace run, with an effect similar to
3585 setting the variable trace-notes.
3588 The trace stop command now interprets any arguments as a note to be
3589 mentioned along with the tstatus report that the trace was stopped
3590 with a command. The effect is similar to setting the variable
3593 * Tracepoints can now be enabled and disabled at any time after a trace
3594 experiment has been started using the standard "enable" and "disable"
3595 commands. It is now possible to start a trace experiment with no enabled
3596 tracepoints; GDB will display a warning, but will allow the experiment to
3597 begin, assuming that tracepoints will be enabled as needed while the trace
3600 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3601 locations with 4-byte instructions, when they were previously
3602 limited to locations with instructions of 5 bytes or longer.
3606 set debug dwarf2-read
3607 show debug dwarf2-read
3608 Turns on or off display of debugging messages related to reading
3609 DWARF debug info. The default is off.
3611 set debug symtab-create
3612 show debug symtab-create
3613 Turns on or off display of debugging messages related to symbol table
3614 creation. The default is off.
3617 show extended-prompt
3618 Set the GDB prompt, and allow escape sequences to be inserted to
3619 display miscellaneous information (see 'help set extended-prompt'
3620 for the list of sequences). This prompt (and any information
3621 accessed through the escape sequences) is updated every time the
3622 prompt is displayed.
3624 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3625 show print entry-values
3626 Set printing of frame argument values at function entry. In some cases
3627 GDB can determine the value of function argument which was passed by the
3628 function caller, even if the value was modified inside the called function.
3630 set debug entry-values
3631 show debug entry-values
3632 Control display of debugging info for determining frame argument values at
3633 function entry and virtual tail call frames.
3635 set basenames-may-differ
3636 show basenames-may-differ
3637 Set whether a source file may have multiple base names.
3638 (A "base name" is the name of a file with the directory part removed.
3639 Example: The base name of "/home/user/hello.c" is "hello.c".)
3640 If set, GDB will canonicalize file names (e.g., expand symlinks)
3641 before comparing them. Canonicalization is an expensive operation,
3642 but it allows the same file be known by more than one base name.
3643 If not set (the default), all source files are assumed to have just
3644 one base name, and gdb will do file name comparisons more efficiently.
3650 Set a user name and notes for the current and any future trace runs.
3651 This is useful for long-running and/or disconnected traces, to
3652 inform others (or yourself) as to who is running the trace, supply
3653 contact information, or otherwise explain what is going on.
3655 set trace-stop-notes
3656 show trace-stop-notes
3657 Set a note attached to the trace run, that is displayed when the
3658 trace has been stopped by a tstop command. This is useful for
3659 instance as an explanation, if you are stopping a trace run that was
3660 started by someone else.
3662 * New remote packets
3666 Dynamically enable a tracepoint in a started trace experiment.
3670 Dynamically disable a tracepoint in a started trace experiment.
3674 Set the user and notes of the trace run.
3678 Query the current status of a tracepoint.
3682 Query the minimum length of instruction at which a fast tracepoint may
3685 * Dcache size (number of lines) and line-size are now runtime-configurable
3686 via "set dcache line" and "set dcache line-size" commands.
3690 Texas Instruments TMS320C6x tic6x-*-*
3694 Renesas RL78 rl78-*-elf
3696 *** Changes in GDB 7.3.1
3698 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3700 *** Changes in GDB 7.3
3702 * GDB has a new command: "thread find [REGEXP]".
3703 It finds the thread id whose name, target id, or thread extra info
3704 matches the given regular expression.
3706 * The "catch syscall" command now works on mips*-linux* targets.
3708 * The -data-disassemble MI command now supports modes 2 and 3 for
3709 dumping the instruction opcodes.
3711 * New command line options
3713 -data-directory DIR Specify DIR as the "data-directory".
3714 This is mostly for testing purposes.
3716 * The "maint set python auto-load on|off" command has been renamed to
3717 "set auto-load-scripts on|off".
3719 * GDB has a new command: "set directories".
3720 It is like the "dir" command except that it replaces the
3721 source path list instead of augmenting it.
3723 * GDB now understands thread names.
3725 On GNU/Linux, "info threads" will display the thread name as set by
3726 prctl or pthread_setname_np.
3728 There is also a new command, "thread name", which can be used to
3729 assign a name internally for GDB to display.
3732 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3733 has been integrated into GDB.
3737 ** The function gdb.Write now accepts an optional keyword 'stream'.
3738 This keyword, when provided, will direct the output to either
3739 stdout, stderr, or GDB's logging output.
3741 ** Parameters can now be be sub-classed in Python, and in particular
3742 you may implement the get_set_doc and get_show_doc functions.
3743 This improves how Parameter set/show documentation is processed
3744 and allows for more dynamic content.
3746 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3747 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3748 have an is_valid method.
3750 ** Breakpoints can now be sub-classed in Python, and in particular
3751 you may implement a 'stop' function that is executed each time
3752 the inferior reaches that breakpoint.
3754 ** New function gdb.lookup_global_symbol looks up a global symbol.
3756 ** GDB values in Python are now callable if the value represents a
3757 function. For example, if 'some_value' represents a function that
3758 takes two integer parameters and returns a value, you can call
3759 that function like so:
3761 result = some_value (10,20)
3763 ** Module gdb.types has been added.
3764 It contains a collection of utilities for working with gdb.Types objects:
3765 get_basic_type, has_field, make_enum_dict.
3767 ** Module gdb.printing has been added.
3768 It contains utilities for writing and registering pretty-printers.
3769 New classes: PrettyPrinter, SubPrettyPrinter,
3770 RegexpCollectionPrettyPrinter.
3771 New function: register_pretty_printer.
3773 ** New commands "info pretty-printers", "enable pretty-printer" and
3774 "disable pretty-printer" have been added.
3776 ** gdb.parameter("directories") is now available.
3778 ** New function gdb.newest_frame returns the newest frame in the
3781 ** The gdb.InferiorThread class has a new "name" attribute. This
3782 holds the thread's name.
3784 ** Python Support for Inferior events.
3785 Python scripts can add observers to be notified of events
3786 occurring in the process being debugged.
3787 The following events are currently supported:
3788 - gdb.events.cont Continue event.
3789 - gdb.events.exited Inferior exited event.
3790 - gdb.events.stop Signal received, and Breakpoint hit events.
3794 ** GDB now puts template parameters in scope when debugging in an
3795 instantiation. For example, if you have:
3797 template<int X> int func (void) { return X; }
3799 then if you step into func<5>, "print X" will show "5". This
3800 feature requires proper debuginfo support from the compiler; it
3801 was added to GCC 4.5.
3803 ** The motion commands "next", "finish", "until", and "advance" now
3804 work better when exceptions are thrown. In particular, GDB will
3805 no longer lose control of the inferior; instead, the GDB will
3806 stop the inferior at the point at which the exception is caught.
3807 This functionality requires a change in the exception handling
3808 code that was introduced in GCC 4.5.
3810 * GDB now follows GCC's rules on accessing volatile objects when
3811 reading or writing target state during expression evaluation.
3812 One notable difference to prior behavior is that "print x = 0"
3813 no longer generates a read of x; the value of the assignment is
3814 now always taken directly from the value being assigned.
3816 * GDB now has some support for using labels in the program's source in
3817 linespecs. For instance, you can use "advance label" to continue
3818 execution to a label.
3820 * GDB now has support for reading and writing a new .gdb_index
3821 section. This section holds a fast index of DWARF debugging
3822 information and can be used to greatly speed up GDB startup and
3823 operation. See the documentation for `save gdb-index' for details.
3825 * The "watch" command now accepts an optional "-location" argument.
3826 When used, this causes GDB to watch the memory referred to by the
3827 expression. Such a watchpoint is never deleted due to it going out
3830 * GDB now supports thread debugging of core dumps on GNU/Linux.
3832 GDB now activates thread debugging using the libthread_db library
3833 when debugging GNU/Linux core dumps, similarly to when debugging
3834 live processes. As a result, when debugging a core dump file, GDB
3835 is now able to display pthread_t ids of threads. For example, "info
3836 threads" shows the same output as when debugging the process when it
3837 was live. In earlier releases, you'd see something like this:
3840 * 1 LWP 6780 main () at main.c:10
3842 While now you see this:
3845 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3847 It is also now possible to inspect TLS variables when debugging core
3850 When debugging a core dump generated on a machine other than the one
3851 used to run GDB, you may need to point GDB at the correct
3852 libthread_db library with the "set libthread-db-search-path"
3853 command. See the user manual for more details on this command.
3855 * When natively debugging programs on PowerPC BookE processors running
3856 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3857 which stop execution of the inferior whenever it executes an instruction
3858 at any address within the specified range. See the "PowerPC Embedded"
3859 section in the user manual for more details.
3861 * New features in the GDB remote stub, GDBserver
3863 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3864 and i686 LynxOS (version 5.x).
3866 ** GDBserver is now supported on Blackfin Linux.
3868 * New native configurations
3870 ia64 HP-UX ia64-*-hpux*
3874 Analog Devices, Inc. Blackfin Processor bfin-*
3876 * Ada task switching is now supported on sparc-elf targets when
3877 debugging a program using the Ravenscar Profile. For more information,
3878 see the "Tasking Support when using the Ravenscar Profile" section
3879 in the GDB user manual.
3881 * Guile support was removed.
3883 * New features in the GNU simulator
3885 ** The --map-info flag lists all known core mappings.
3887 ** CFI flashes may be simulated via the "cfi" device.
3889 *** Changes in GDB 7.2
3891 * Shared library support for remote targets by default
3893 When GDB is configured for a generic, non-OS specific target, like
3894 for example, --target=arm-eabi or one of the many *-*-elf targets,
3895 GDB now queries remote stubs for loaded shared libraries using the
3896 `qXfer:libraries:read' packet. Previously, shared library support
3897 was always disabled for such configurations.
3901 ** Argument Dependent Lookup (ADL)
3903 In C++ ADL lookup directs function search to the namespaces of its
3904 arguments even if the namespace has not been imported.
3914 Here the compiler will search for `foo' in the namespace of 'b'
3915 and find A::foo. GDB now supports this. This construct is commonly
3916 used in the Standard Template Library for operators.
3918 ** Improved User Defined Operator Support
3920 In addition to member operators, GDB now supports lookup of operators
3921 defined in a namespace and imported with a `using' directive, operators
3922 defined in the global scope, operators imported implicitly from an
3923 anonymous namespace, and the ADL operators mentioned in the previous
3925 GDB now also supports proper overload resolution for all the previously
3926 mentioned flavors of operators.
3928 ** static const class members
3930 Printing of static const class members that are initialized in the
3931 class definition has been fixed.
3933 * Windows Thread Information Block access.
3935 On Windows targets, GDB now supports displaying the Windows Thread
3936 Information Block (TIB) structure. This structure is visible either
3937 by using the new command `info w32 thread-information-block' or, by
3938 dereferencing the new convenience variable named `$_tlb', a
3939 thread-specific pointer to the TIB. This feature is also supported
3940 when remote debugging using GDBserver.
3942 * Static tracepoints
3944 Static tracepoints are calls in the user program into a tracing
3945 library. One such library is a port of the LTTng kernel tracer to
3946 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3947 When debugging with GDBserver, GDB now supports combining the GDB
3948 tracepoint machinery with such libraries. For example: the user can
3949 use GDB to probe a static tracepoint marker (a call from the user
3950 program into the tracing library) with the new "strace" command (see
3951 "New commands" below). This creates a "static tracepoint" in the
3952 breakpoint list, that can be manipulated with the same feature set
3953 as fast and regular tracepoints. E.g., collect registers, local and
3954 global variables, collect trace state variables, and define
3955 tracepoint conditions. In addition, the user can collect extra
3956 static tracepoint marker specific data, by collecting the new
3957 $_sdata internal variable. When analyzing the trace buffer, you can
3958 inspect $_sdata like any other variable available to GDB. For more
3959 information, see the "Tracepoints" chapter in GDB user manual. New
3960 remote packets have been defined to support static tracepoints, see
3961 the "New remote packets" section below.
3963 * Better reconstruction of tracepoints after disconnected tracing
3965 GDB will attempt to download the original source form of tracepoint
3966 definitions when starting a trace run, and then will upload these
3967 upon reconnection to the target, resulting in a more accurate
3968 reconstruction of the tracepoints that are in use on the target.
3972 You can now exercise direct control over the ways that GDB can
3973 affect your program. For instance, you can disallow the setting of
3974 breakpoints, so that the program can run continuously (assuming
3975 non-stop mode). In addition, the "observer" variable is available
3976 to switch all of the different controls; in observer mode, GDB
3977 cannot affect the target's behavior at all, which is useful for
3978 tasks like diagnosing live systems in the field.
3980 * The new convenience variable $_thread holds the number of the
3983 * New remote packets
3987 Return the address of the Windows Thread Information Block of a given thread.
3991 In response to several of the tracepoint packets, the target may now
3992 also respond with a number of intermediate `qRelocInsn' request
3993 packets before the final result packet, to have GDB handle
3994 relocating an instruction to execute at a different address. This
3995 is particularly useful for stubs that support fast tracepoints. GDB
3996 reports support for this feature in the qSupported packet.
4000 List static tracepoint markers in the target program.
4004 List static tracepoint markers at a given address in the target
4007 qXfer:statictrace:read
4009 Read the static trace data collected (by a `collect $_sdata'
4010 tracepoint action). The remote stub reports support for this packet
4011 to gdb's qSupported query.
4015 Send the current settings of GDB's permission flags.
4019 Send part of the source (textual) form of a tracepoint definition,
4020 which includes location, conditional, and action list.
4022 * The source command now accepts a -s option to force searching for the
4023 script in the source search path even if the script name specifies
4026 * New features in the GDB remote stub, GDBserver
4028 - GDBserver now support tracepoints (including fast tracepoints, and
4029 static tracepoints). The feature is currently supported by the
4030 i386-linux and amd64-linux builds. See the "Tracepoints support
4031 in gdbserver" section in the manual for more information.
4033 GDBserver JIT compiles the tracepoint's conditional agent
4034 expression bytecode into native code whenever possible for low
4035 overhead dynamic tracepoints conditionals. For such tracepoints,
4036 an expression that examines program state is evaluated when the
4037 tracepoint is reached, in order to determine whether to capture
4038 trace data. If the condition is simple and false, processing the
4039 tracepoint finishes very quickly and no data is gathered.
4041 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4042 for static tracepoints support.
4044 - GDBserver now supports x86_64 Windows 64-bit debugging.
4046 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4047 it understands register description.
4049 * The --batch flag now disables pagination and queries.
4051 * X86 general purpose registers
4053 GDB now supports reading/writing byte, word and double-word x86
4054 general purpose registers directly. This means you can use, say,
4055 $ah or $ax to refer, respectively, to the byte register AH and
4056 16-bit word register AX that are actually portions of the 32-bit
4057 register EAX or 64-bit register RAX.
4059 * The `commands' command now accepts a range of breakpoints to modify.
4060 A plain `commands' following a command that creates multiple
4061 breakpoints affects all the breakpoints set by that command. This
4062 applies to breakpoints set by `rbreak', and also applies when a
4063 single `break' command creates multiple breakpoints (e.g.,
4064 breakpoints on overloaded c++ functions).
4066 * The `rbreak' command now accepts a filename specification as part of
4067 its argument, limiting the functions selected by the regex to those
4068 in the specified file.
4070 * Support for remote debugging Windows and SymbianOS shared libraries
4071 from Unix hosts has been improved. Non Windows GDB builds now can
4072 understand target reported file names that follow MS-DOS based file
4073 system semantics, such as file names that include drive letters and
4074 use the backslash character as directory separator. This makes it
4075 possible to transparently use the "set sysroot" and "set
4076 solib-search-path" on Unix hosts to point as host copies of the
4077 target's shared libraries. See the new command "set
4078 target-file-system-kind" described below, and the "Commands to
4079 specify files" section in the user manual for more information.
4083 eval template, expressions...
4084 Convert the values of one or more expressions under the control
4085 of the string template to a command line, and call it.
4087 set target-file-system-kind unix|dos-based|auto
4088 show target-file-system-kind
4089 Set or show the assumed file system kind for target reported file
4092 save breakpoints <filename>
4093 Save all current breakpoint definitions to a file suitable for use
4094 in a later debugging session. To read the saved breakpoint
4095 definitions, use the `source' command.
4097 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4100 info static-tracepoint-markers
4101 Display information about static tracepoint markers in the target.
4103 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4104 Define a static tracepoint by probing a marker at the given
4105 function, line, address, or marker ID.
4109 Enable and disable observer mode.
4111 set may-write-registers on|off
4112 set may-write-memory on|off
4113 set may-insert-breakpoints on|off
4114 set may-insert-tracepoints on|off
4115 set may-insert-fast-tracepoints on|off
4116 set may-interrupt on|off
4117 Set individual permissions for GDB effects on the target. Note that
4118 some of these settings can have undesirable or surprising
4119 consequences, particularly when changed in the middle of a session.
4120 For instance, disabling the writing of memory can prevent
4121 breakpoints from being inserted, cause single-stepping to fail, or
4122 even crash your program, if you disable after breakpoints have been
4123 inserted. However, GDB should not crash.
4125 set record memory-query on|off
4126 show record memory-query
4127 Control whether to stop the inferior if memory changes caused
4128 by an instruction cannot be recorded.
4133 The disassemble command now supports "start,+length" form of two arguments.
4137 ** GDB now provides a new directory location, called the python directory,
4138 where Python scripts written for GDB can be installed. The location
4139 of that directory is <data-directory>/python, where <data-directory>
4140 is the GDB data directory. For more details, see section `Scripting
4141 GDB using Python' in the manual.
4143 ** The GDB Python API now has access to breakpoints, symbols, symbol
4144 tables, program spaces, inferiors, threads and frame's code blocks.
4145 Additionally, GDB Parameters can now be created from the API, and
4146 manipulated via set/show in the CLI.
4148 ** New functions gdb.target_charset, gdb.target_wide_charset,
4149 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4151 ** New exception gdb.GdbError.
4153 ** Pretty-printers are now also looked up in the current program space.
4155 ** Pretty-printers can now be individually enabled and disabled.
4157 ** GDB now looks for names of Python scripts to auto-load in a
4158 special section named `.debug_gdb_scripts', in addition to looking
4159 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4161 * Tracepoint actions were unified with breakpoint commands. In particular,
4162 there are no longer differences in "info break" output for breakpoints and
4163 tracepoints and the "commands" command can be used for both tracepoints and
4164 regular breakpoints.
4168 ARM Symbian arm*-*-symbianelf*
4170 * D language support.
4171 GDB now supports debugging programs written in the D programming
4174 * GDB now supports the extended ptrace interface for PowerPC which is
4175 available since Linux kernel version 2.6.34. This automatically enables
4176 any hardware breakpoints and additional hardware watchpoints available in
4177 the processor. The old ptrace interface exposes just one hardware
4178 watchpoint and no hardware breakpoints.
4180 * GDB is now able to use the Data Value Compare (DVC) register available on
4181 embedded PowerPC processors to implement in hardware simple watchpoint
4182 conditions of the form:
4184 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4186 This works in native GDB running on Linux kernels with the extended ptrace
4187 interface mentioned above.
4189 *** Changes in GDB 7.1
4193 ** Namespace Support
4195 GDB now supports importing of namespaces in C++. This enables the
4196 user to inspect variables from imported namespaces. Support for
4197 namepace aliasing has also been added. So, if a namespace is
4198 aliased in the current scope (e.g. namepace C=A; ) the user can
4199 print variables using the alias (e.g. (gdb) print C::x).
4203 All known bugs relating to the printing of virtual base class were
4204 fixed. It is now possible to call overloaded static methods using a
4209 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4210 and reinterpret_cast<> are now handled by the C++ expression parser.
4214 Xilinx MicroBlaze microblaze-*-*
4219 Xilinx MicroBlaze microblaze
4222 * Multi-program debugging.
4224 GDB now has support for multi-program (a.k.a. multi-executable or
4225 multi-exec) debugging. This allows for debugging multiple inferiors
4226 simultaneously each running a different program under the same GDB
4227 session. See "Debugging Multiple Inferiors and Programs" in the
4228 manual for more information. This implied some user visible changes
4229 in the multi-inferior support. For example, "info inferiors" now
4230 lists inferiors that are not running yet or that have exited
4231 already. See also "New commands" and "New options" below.
4233 * New tracing features
4235 GDB's tracepoint facility now includes several new features:
4237 ** Trace state variables
4239 GDB tracepoints now include support for trace state variables, which
4240 are variables managed by the target agent during a tracing
4241 experiment. They are useful for tracepoints that trigger each
4242 other, so for instance one tracepoint can count hits in a variable,
4243 and then a second tracepoint has a condition that is true when the
4244 count reaches a particular value. Trace state variables share the
4245 $-syntax of GDB convenience variables, and can appear in both
4246 tracepoint actions and condition expressions. Use the "tvariable"
4247 command to create, and "info tvariables" to view; see "Trace State
4248 Variables" in the manual for more detail.
4252 GDB now includes an option for defining fast tracepoints, which
4253 targets may implement more efficiently, such as by installing a jump
4254 into the target agent rather than a trap instruction. The resulting
4255 speedup can be by two orders of magnitude or more, although the
4256 tradeoff is that some program locations on some target architectures
4257 might not allow fast tracepoint installation, for instance if the
4258 instruction to be replaced is shorter than the jump. To request a
4259 fast tracepoint, use the "ftrace" command, with syntax identical to
4260 the regular trace command.
4262 ** Disconnected tracing
4264 It is now possible to detach GDB from the target while it is running
4265 a trace experiment, then reconnect later to see how the experiment
4266 is going. In addition, a new variable disconnected-tracing lets you
4267 tell the target agent whether to continue running a trace if the
4268 connection is lost unexpectedly.
4272 GDB now has the ability to save the trace buffer into a file, and
4273 then use that file as a target, similarly to you can do with
4274 corefiles. You can select trace frames, print data that was
4275 collected in them, and use tstatus to display the state of the
4276 tracing run at the moment that it was saved. To create a trace
4277 file, use "tsave <filename>", and to use it, do "target tfile
4280 ** Circular trace buffer
4282 You can ask the target agent to handle the trace buffer as a
4283 circular buffer, discarding the oldest trace frames to make room for
4284 newer ones, by setting circular-trace-buffer to on. This feature may
4285 not be available for all target agents.
4290 The disassemble command, when invoked with two arguments, now requires
4291 the arguments to be comma-separated.
4294 The info variables command now displays variable definitions. Files
4295 which only declare a variable are not shown.
4298 The source command is now capable of sourcing Python scripts.
4299 This feature is dependent on the debugger being build with Python
4302 Related to this enhancement is also the introduction of a new command
4303 "set script-extension" (see below).
4305 * New commands (for set/show, see "New options" below)
4307 record save [<FILENAME>]
4308 Save a file (in core file format) containing the process record
4309 execution log for replay debugging at a later time.
4311 record restore <FILENAME>
4312 Restore the process record execution log that was saved at an
4313 earlier time, for replay debugging.
4315 add-inferior [-copies <N>] [-exec <FILENAME>]
4318 clone-inferior [-copies <N>] [ID]
4319 Make a new inferior ready to execute the same program another
4320 inferior has loaded.
4325 maint info program-spaces
4326 List the program spaces loaded into GDB.
4328 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4329 show remote interrupt-sequence
4330 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4331 as the sequence to the remote target in order to interrupt the execution.
4332 Ctrl-C is a default. Some system prefers BREAK which is high level of
4333 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4334 Magic SysRq g. It is BREAK signal and character 'g'.
4336 set remote interrupt-on-connect [on | off]
4337 show remote interrupt-on-connect
4338 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4339 remote target when gdb connects to it. This is needed when you debug
4342 set remotebreak [on | off]
4344 Deprecated. Use "set/show remote interrupt-sequence" instead.
4346 tvariable $NAME [ = EXP ]
4347 Create or modify a trace state variable.
4350 List trace state variables and their values.
4352 delete tvariable $NAME ...
4353 Delete one or more trace state variables.
4356 Evaluate the given expressions without collecting anything into the
4357 trace buffer. (Valid in tracepoint actions only.)
4359 ftrace FN / FILE:LINE / *ADDR
4360 Define a fast tracepoint at the given function, line, or address.
4362 * New expression syntax
4364 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4365 GDB now parses 0b101010 identically with 42.
4369 set follow-exec-mode new|same
4370 show follow-exec-mode
4371 Control whether GDB reuses the same inferior across an exec call or
4372 creates a new one. This is useful to be able to restart the old
4373 executable after the inferior having done an exec call.
4375 set default-collect EXPR, ...
4376 show default-collect
4377 Define a list of expressions to be collected at each tracepoint.
4378 This is a useful way to ensure essential items are not overlooked,
4379 such as registers or a critical global variable.
4381 set disconnected-tracing
4382 show disconnected-tracing
4383 If set to 1, the target is instructed to continue tracing if it
4384 loses its connection to GDB. If 0, the target is to stop tracing
4387 set circular-trace-buffer
4388 show circular-trace-buffer
4389 If set to on, the target is instructed to use a circular trace buffer
4390 and discard the oldest trace frames instead of stopping the trace due
4391 to a full trace buffer. If set to off, the trace stops when the buffer
4392 fills up. Some targets may not support this.
4394 set script-extension off|soft|strict
4395 show script-extension
4396 If set to "off", the debugger does not perform any script language
4397 recognition, and all sourced files are assumed to be GDB scripts.
4398 If set to "soft" (the default), files are sourced according to
4399 filename extension, falling back to GDB scripts if the first
4401 If set to "strict", files are sourced according to filename extension.
4403 set ada trust-PAD-over-XVS on|off
4404 show ada trust-PAD-over-XVS
4405 If off, activate a workaround against a bug in the debugging information
4406 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4407 the GCC sources for more information about the GNAT encoding and
4408 PAD types in particular). It is always safe to set this option to
4409 off, but this introduces a slight performance penalty. The default
4412 * Python API Improvements
4414 ** GDB provides the new class gdb.LazyString. This is useful in
4415 some pretty-printing cases. The new method gdb.Value.lazy_string
4416 provides a simple way to create objects of this type.
4418 ** The fields returned by gdb.Type.fields now have an
4419 `is_base_class' attribute.
4421 ** The new method gdb.Type.range returns the range of an array type.
4423 ** The new method gdb.parse_and_eval can be used to parse and
4424 evaluate an expression.
4426 * New remote packets
4429 Define a trace state variable.
4432 Get the current value of a trace state variable.
4435 Set desired tracing behavior upon disconnection.
4438 Set the trace buffer to be linear or circular.
4441 Get data about the tracepoints currently in use.
4445 Process record now works correctly with hardware watchpoints.
4447 Multiple bug fixes have been made to the mips-irix port, making it
4448 much more reliable. In particular:
4449 - Debugging threaded applications is now possible again. Previously,
4450 GDB would hang while starting the program, or while waiting for
4451 the program to stop at a breakpoint.
4452 - Attaching to a running process no longer hangs.
4453 - An error occurring while loading a core file has been fixed.
4454 - Changing the value of the PC register now works again. This fixes
4455 problems observed when using the "jump" command, or when calling
4456 a function from GDB, or even when assigning a new value to $pc.
4457 - With the "finish" and "return" commands, the return value for functions
4458 returning a small array is now correctly printed.
4459 - It is now possible to break on shared library code which gets executed
4460 during a shared library init phase (code executed while executing
4461 their .init section). Previously, the breakpoint would have no effect.
4462 - GDB is now able to backtrace through the signal handler for
4463 non-threaded programs.
4465 PIE (Position Independent Executable) programs debugging is now supported.
4466 This includes debugging execution of PIC (Position Independent Code) shared
4467 libraries although for that, it should be possible to run such libraries as an
4470 *** Changes in GDB 7.0
4472 * GDB now has an interface for JIT compilation. Applications that
4473 dynamically generate code can create symbol files in memory and register
4474 them with GDB. For users, the feature should work transparently, and
4475 for JIT developers, the interface is documented in the GDB manual in the
4476 "JIT Compilation Interface" chapter.
4478 * Tracepoints may now be conditional. The syntax is as for
4479 breakpoints; either an "if" clause appended to the "trace" command,
4480 or the "condition" command is available. GDB sends the condition to
4481 the target for evaluation using the same bytecode format as is used
4482 for tracepoint actions.
4484 * The disassemble command now supports: an optional /r modifier, print the
4485 raw instructions in hex as well as in symbolic form, and an optional /m
4486 modifier to print mixed source+assembly.
4488 * Process record and replay
4490 In a architecture environment that supports ``process record and
4491 replay'', ``process record and replay'' target can record a log of
4492 the process execution, and replay it with both forward and reverse
4495 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4496 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4497 set execution-direction {forward|reverse}, for targets that support
4500 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4501 feature is available with a native GDB running on kernel version
4504 * GDB now has support for multi-byte and wide character sets on the
4505 target. Strings whose character type is wchar_t, char16_t, or
4506 char32_t are now correctly printed. GDB supports wide- and unicode-
4507 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4508 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4509 `printf'. This feature requires iconv to work properly; if your
4510 system does not have a working iconv, GDB can use GNU libiconv. See
4511 the installation instructions for more information.
4513 * GDB now supports automatic retrieval of shared library files from
4514 remote targets. To use this feature, specify a system root that begins
4515 with the `remote:' prefix, either via the `set sysroot' command or via
4516 the `--with-sysroot' configure-time option.
4518 * "info sharedlibrary" now takes an optional regex of libraries to show,
4519 and it now reports if a shared library has no debugging information.
4521 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4522 now complete on file names.
4524 * When completing in expressions, gdb will attempt to limit
4525 completions to allowable structure or union fields, where appropriate.
4526 For instance, consider:
4528 # struct example { int f1; double f2; };
4529 # struct example variable;
4532 If the user types TAB at the end of this command line, the available
4533 completions will be "f1" and "f2".
4535 * Inlined functions are now supported. They show up in backtraces, and
4536 the "step", "next", and "finish" commands handle them automatically.
4538 * GDB now supports the token-splicing (##) and stringification (#)
4539 operators when expanding macros. It also supports variable-arity
4542 * GDB now supports inspecting extra signal information, exported by
4543 the new $_siginfo convenience variable. The feature is currently
4544 implemented on linux ARM, i386 and amd64.
4546 * GDB can now display the VFP floating point registers and NEON vector
4547 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4548 can provide these registers (requires Linux 2.6.30 or later). Remote
4549 and simulator targets may also provide them.
4551 * New remote packets
4554 Search memory for a sequence of bytes.
4557 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4558 operation over reliable transport links. Use of this packet is
4559 controlled by the `set remote noack-packet' command.
4562 Kill the process with the specified process ID. Use this in preference
4563 to `k' when multiprocess protocol extensions are supported.
4566 Obtains additional operating system information
4570 Read or write additional signal information.
4572 * Removed remote protocol undocumented extension
4574 An undocumented extension to the remote protocol's `S' stop reply
4575 packet that permitted the stub to pass a process id was removed.
4576 Remote servers should use the `T' stop reply packet instead.
4578 * GDB now supports multiple function calling conventions according to the
4579 DWARF-2 DW_AT_calling_convention function attribute.
4581 * The SH target utilizes the aforementioned change to distinguish between gcc
4582 and Renesas calling convention. It also adds the new CLI commands
4583 `set/show sh calling-convention'.
4585 * GDB can now read compressed debug sections, as produced by GNU gold
4586 with the --compress-debug-sections=zlib flag.
4588 * 64-bit core files are now supported on AIX.
4590 * Thread switching is now supported on Tru64.
4592 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4593 which will be allocated using malloc later in program execution.
4595 * The qXfer:libraries:read remote protocol packet now allows passing a
4596 list of section offsets.
4598 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4599 conditions handling signals delivered during attach or thread creation
4600 have also been fixed.
4602 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4603 From the user's standpoint, all unqualified instances of True and False
4604 are treated as the standard definitions, regardless of context.
4606 * GDB now parses C++ symbol and type names more flexibly. For
4609 template<typename T> class C { };
4612 GDB will now correctly handle all of:
4614 ptype C<char const *>
4615 ptype C<char const*>
4616 ptype C<const char *>
4617 ptype C<const char*>
4619 * New features in the GDB remote stub, gdbserver
4621 - The "--wrapper" command-line argument tells gdbserver to use a
4622 wrapper program to launch programs for debugging.
4624 - On PowerPC and S/390 targets, it is now possible to use a single
4625 gdbserver executable to debug both 32-bit and 64-bit programs.
4626 (This requires gdbserver itself to be built as a 64-bit executable.)
4628 - gdbserver uses the new noack protocol mode for TCP connections to
4629 reduce communications latency, if also supported and enabled in GDB.
4631 - Support for the sparc64-linux-gnu target is now included in
4634 - The amd64-linux build of gdbserver now supports debugging both
4635 32-bit and 64-bit programs.
4637 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4638 now support hardware watchpoints, and will use them automatically
4643 GDB now has support for scripting using Python. Whether this is
4644 available is determined at configure time.
4646 New GDB commands can now be written in Python.
4648 * Ada tasking support
4650 Ada tasks can now be inspected in GDB. The following commands have
4654 Print the list of Ada tasks.
4656 Print detailed information about task number N.
4658 Print the task number of the current task.
4660 Switch the context of debugging to task number N.
4662 * Support for user-defined prefixed commands. The "define" command can
4663 add new commands to existing prefixes, e.g. "target".
4665 * Multi-inferior, multi-process debugging.
4667 GDB now has generalized support for multi-inferior debugging. See
4668 "Debugging Multiple Inferiors" in the manual for more information.
4669 Although availability still depends on target support, the command
4670 set is more uniform now. The GNU/Linux specific multi-forks support
4671 has been migrated to this new framework. This implied some user
4672 visible changes; see "New commands" and also "Removed commands"
4675 * Target descriptions can now describe the target OS ABI. See the
4676 "Target Description Format" section in the user manual for more
4679 * Target descriptions can now describe "compatible" architectures
4680 to indicate that the target can execute applications for a different
4681 architecture in addition to those for the main target architecture.
4682 See the "Target Description Format" section in the user manual for
4685 * Multi-architecture debugging.
4687 GDB now includes general supports for debugging applications on
4688 hybrid systems that use more than one single processor architecture
4689 at the same time. Each such hybrid architecture still requires
4690 specific support to be added. The only hybrid architecture supported
4691 in this version of GDB is the Cell Broadband Engine.
4693 * GDB now supports integrated debugging of Cell/B.E. applications that
4694 use both the PPU and SPU architectures. To enable support for hybrid
4695 Cell/B.E. debugging, you need to configure GDB to support both the
4696 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4697 --enable-targets configure option.
4699 * Non-stop mode debugging.
4701 For some targets, GDB now supports an optional mode of operation in
4702 which you can examine stopped threads while other threads continue
4703 to execute freely. This is referred to as non-stop mode, with the
4704 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4705 section in the user manual for more information.
4707 To be able to support remote non-stop debugging, a remote stub needs
4708 to implement the non-stop mode remote protocol extensions, as
4709 described in the "Remote Non-Stop" section of the user manual. The
4710 GDB remote stub, gdbserver, has been adjusted to support these
4711 extensions on linux targets.
4713 * New commands (for set/show, see "New options" below)
4715 catch syscall [NAME(S) | NUMBER(S)]
4716 Catch system calls. Arguments, which should be names of system
4717 calls or their numbers, mean catch only those syscalls. Without
4718 arguments, every syscall will be caught. When the inferior issues
4719 any of the specified syscalls, GDB will stop and announce the system
4720 call, both when it is called and when its call returns. This
4721 feature is currently available with a native GDB running on the
4722 Linux Kernel, under the following architectures: x86, x86_64,
4723 PowerPC and PowerPC64.
4725 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4727 Search memory for a sequence of bytes.
4729 maint set python print-stack
4730 maint show python print-stack
4731 Show a stack trace when an error is encountered in a Python script.
4734 Invoke CODE by passing it to the Python interpreter.
4739 These allow macros to be defined, undefined, and listed
4743 Show operating system information about processes.
4746 List the inferiors currently under GDB's control.
4749 Switch focus to inferior number NUM.
4752 Detach from inferior number NUM.
4755 Kill inferior number NUM.
4759 set spu stop-on-load
4760 show spu stop-on-load
4761 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4763 set spu auto-flush-cache
4764 show spu auto-flush-cache
4765 Control whether to automatically flush the software-managed cache
4766 during Cell/B.E. debugging.
4768 set sh calling-convention
4769 show sh calling-convention
4770 Control the calling convention used when calling SH target functions.
4773 show debug timestamp
4774 Control display of timestamps with GDB debugging output.
4776 set disassemble-next-line
4777 show disassemble-next-line
4778 Control display of disassembled source lines or instructions when
4781 set remote noack-packet
4782 show remote noack-packet
4783 Set/show the use of remote protocol QStartNoAckMode packet. See above
4784 under "New remote packets."
4786 set remote query-attached-packet
4787 show remote query-attached-packet
4788 Control use of remote protocol `qAttached' (query-attached) packet.
4790 set remote read-siginfo-object
4791 show remote read-siginfo-object
4792 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4795 set remote write-siginfo-object
4796 show remote write-siginfo-object
4797 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4800 set remote reverse-continue
4801 show remote reverse-continue
4802 Control use of remote protocol 'bc' (reverse-continue) packet.
4804 set remote reverse-step
4805 show remote reverse-step
4806 Control use of remote protocol 'bs' (reverse-step) packet.
4808 set displaced-stepping
4809 show displaced-stepping
4810 Control displaced stepping mode. Displaced stepping is a way to
4811 single-step over breakpoints without removing them from the debuggee.
4812 Also known as "out-of-line single-stepping".
4815 show debug displaced
4816 Control display of debugging info for displaced stepping.
4818 maint set internal-error
4819 maint show internal-error
4820 Control what GDB does when an internal error is detected.
4822 maint set internal-warning
4823 maint show internal-warning
4824 Control what GDB does when an internal warning is detected.
4829 Use a wrapper program to launch programs for debugging.
4831 set multiple-symbols (all|ask|cancel)
4832 show multiple-symbols
4833 The value of this variable can be changed to adjust the debugger behavior
4834 when an expression or a breakpoint location contains an ambiguous symbol
4835 name (an overloaded function name, for instance).
4837 set breakpoint always-inserted
4838 show breakpoint always-inserted
4839 Keep breakpoints always inserted in the target, as opposed to inserting
4840 them when resuming the target, and removing them when the target stops.
4841 This option can improve debugger performance on slow remote targets.
4843 set arm fallback-mode (arm|thumb|auto)
4844 show arm fallback-mode
4845 set arm force-mode (arm|thumb|auto)
4847 These commands control how ARM GDB determines whether instructions
4848 are ARM or Thumb. The default for both settings is auto, which uses
4849 the current CPSR value for instructions without symbols; previous
4850 versions of GDB behaved as if "set arm fallback-mode arm".
4852 set disable-randomization
4853 show disable-randomization
4854 Standalone programs run with the virtual address space randomization enabled
4855 by default on some platforms. This option keeps the addresses stable across
4856 multiple debugging sessions.
4860 Control whether other threads are stopped or not when some thread hits
4865 Requests that asynchronous execution is enabled in the target, if available.
4866 In this case, it's possible to resume target in the background, and interact
4867 with GDB while the target is running. "show target-async" displays the
4868 current state of asynchronous execution of the target.
4870 set target-wide-charset
4871 show target-wide-charset
4872 The target-wide-charset is the name of the character set that GDB
4873 uses when printing characters whose type is wchar_t.
4875 set tcp auto-retry (on|off)
4877 set tcp connect-timeout
4878 show tcp connect-timeout
4879 These commands allow GDB to retry failed TCP connections to a remote stub
4880 with a specified timeout period; this is useful if the stub is launched
4881 in parallel with GDB but may not be ready to accept connections immediately.
4883 set libthread-db-search-path
4884 show libthread-db-search-path
4885 Control list of directories which GDB will search for appropriate
4888 set schedule-multiple (on|off)
4889 show schedule-multiple
4890 Allow GDB to resume all threads of all processes or only threads of
4891 the current process.
4895 Use more aggressive caching for accesses to the stack. This improves
4896 performance of remote debugging (particularly backtraces) without
4897 affecting correctness.
4899 set interactive-mode (on|off|auto)
4900 show interactive-mode
4901 Control whether GDB runs in interactive mode (on) or not (off).
4902 When in interactive mode, GDB waits for the user to answer all
4903 queries. Otherwise, GDB does not wait and assumes the default
4904 answer. When set to auto (the default), GDB determines which
4905 mode to use based on the stdin settings.
4910 For program forks, this is replaced by the new more generic `info
4911 inferiors' command. To list checkpoints, you can still use the
4912 `info checkpoints' command, which was an alias for the `info forks'
4916 Replaced by the new `inferior' command. To switch between
4917 checkpoints, you can still use the `restart' command, which was an
4918 alias for the `fork' command.
4921 This is removed, since some targets don't have a notion of
4922 processes. To switch between processes, you can still use the
4923 `inferior' command using GDB's own inferior number.
4926 For program forks, this is replaced by the new more generic `kill
4927 inferior' command. To delete a checkpoint, you can still use the
4928 `delete checkpoint' command, which was an alias for the `delete
4932 For program forks, this is replaced by the new more generic `detach
4933 inferior' command. To detach a checkpoint, you can still use the
4934 `detach checkpoint' command, which was an alias for the `detach
4937 * New native configurations
4939 x86/x86_64 Darwin i[34567]86-*-darwin*
4941 x86_64 MinGW x86_64-*-mingw*
4945 Lattice Mico32 lm32-*
4946 x86 DICOS i[34567]86-*-dicos*
4947 x86_64 DICOS x86_64-*-dicos*
4950 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4951 (mingw32ce) debugging.
4957 These commands were actually not implemented on any target.
4959 *** Changes in GDB 6.8
4961 * New native configurations
4963 NetBSD/hppa hppa*-*netbsd*
4964 Xtensa GNU/Linux xtensa*-*-linux*
4968 NetBSD/hppa hppa*-*-netbsd*
4969 Xtensa GNU/Linux xtensa*-*-linux*
4971 * Change in command line behavior -- corefiles vs. process ids.
4973 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4974 attaching to process NUMBER fails, GDB no longer attempts to open a
4975 core file named NUMBER. Attaching to a program using the -c option
4976 is no longer supported. Instead, use the '-p' or '--pid' options.
4978 * GDB can now be built as a native debugger for debugging Windows x86
4979 (mingw32) Portable Executable (PE) programs.
4981 * Pending breakpoints no longer change their number when their address
4984 * GDB now supports breakpoints with multiple locations,
4985 including breakpoints on C++ constructors, inside C++ templates,
4986 and in inlined functions.
4988 * GDB's ability to debug optimized code has been improved. GDB more
4989 accurately identifies function bodies and lexical blocks that occupy
4990 more than one contiguous range of addresses.
4992 * Target descriptions can now describe registers for PowerPC.
4994 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4995 registers on PowerPC targets.
4997 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4998 targets even when the libthread_db library is not available.
5000 * The GDB remote stub, gdbserver, now supports the new file transfer
5001 commands (remote put, remote get, and remote delete).
5003 * The GDB remote stub, gdbserver, now supports run and attach in
5004 extended-remote mode.
5006 * hppa*64*-*-hpux11* target broken
5007 The debugger is unable to start a program and fails with the following
5008 error: "Error trying to get information about dynamic linker".
5009 The gdb-6.7 release is also affected.
5011 * GDB now supports the --enable-targets= configure option to allow
5012 building a single GDB executable that supports multiple remote
5013 target architectures.
5015 * GDB now supports debugging C and C++ programs which use the
5016 Decimal Floating Point extension. In addition, the PowerPC target
5017 now has a set of pseudo-registers to inspect decimal float values
5018 stored in two consecutive float registers.
5020 * The -break-insert MI command can optionally create pending
5023 * Improved support for debugging Ada
5024 Many improvements to the Ada language support have been made. These
5026 - Better support for Ada2005 interface types
5027 - Improved handling of arrays and slices in general
5028 - Better support for Taft-amendment types
5029 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5031 - Improved command completion in Ada
5034 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5039 set print frame-arguments (all|scalars|none)
5040 show print frame-arguments
5041 The value of this variable can be changed to control which argument
5042 values should be printed by the debugger when displaying a frame.
5047 Transfer files to and from a remote target, and delete remote files.
5054 Transfer files to and from a remote target, and delete remote files.
5056 * New remote packets
5063 Open, close, read, write, and delete files on the remote system.
5066 Attach to an existing process on the remote system, in extended-remote
5070 Run a new process on the remote system, in extended-remote mode.
5072 *** Changes in GDB 6.7
5074 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5075 bfd, libiberty and opcodes, as revealed by static analysis donated by
5076 Coverity, Inc. (http://scan.coverity.com).
5078 * When looking up multiply-defined global symbols, GDB will now prefer the
5079 symbol definition in the current shared library if it was built using the
5080 -Bsymbolic linker option.
5082 * When the Text User Interface (TUI) is not configured, GDB will now
5083 recognize the -tui command-line option and print a message that the TUI
5086 * The GDB remote stub, gdbserver, now has lower overhead for high
5087 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5089 * GDB for MIPS targets now autodetects whether a remote target provides
5090 32-bit or 64-bit register values.
5092 * Support for C++ member pointers has been improved.
5094 * GDB now understands XML target descriptions, which specify the
5095 target's overall architecture. GDB can read a description from
5096 a local file or over the remote serial protocol.
5098 * Vectors of single-byte data use a new integer type which is not
5099 automatically displayed as character or string data.
5101 * The /s format now works with the print command. It displays
5102 arrays of single-byte integers and pointers to single-byte integers
5105 * Target descriptions can now describe target-specific registers,
5106 for architectures which have implemented the support (currently
5107 only ARM, M68K, and MIPS).
5109 * GDB and the GDB remote stub, gdbserver, now support the XScale
5112 * The GDB remote stub, gdbserver, has been updated to support
5113 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5114 has been rewritten to use the standard GDB remote protocol.
5116 * GDB can now step into C++ functions which are called through thunks.
5118 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5120 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5121 layout. It also supports a TextSeg= and DataSeg= response when only
5122 segment base addresses (rather than offsets) are available.
5124 * The /i format now outputs any trailing branch delay slot instructions
5125 immediately following the last instruction within the count specified.
5127 * The GDB remote protocol "T" stop reply packet now supports a
5128 "library" response. Combined with the new "qXfer:libraries:read"
5129 packet, this response allows GDB to debug shared libraries on targets
5130 where the operating system manages the list of loaded libraries (e.g.
5131 Windows and SymbianOS).
5133 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5134 (DLLs) on Windows and Windows CE targets.
5136 * GDB now supports a faster verification that a .debug file matches its binary
5137 according to its build-id signature, if the signature is present.
5143 Enable or disable hardware flow control (RTS/CTS) on the serial port
5144 when debugging using remote targets.
5146 set mem inaccessible-by-default
5147 show mem inaccessible-by-default
5148 If the target supplies a memory map, for instance via the remote
5149 protocol's "qXfer:memory-map:read" packet, setting this variable
5150 prevents GDB from accessing memory outside the memory map. This
5151 is useful for targets with memory mapped registers or which react
5152 badly to accesses of unmapped address space.
5154 set breakpoint auto-hw
5155 show breakpoint auto-hw
5156 If the target supplies a memory map, for instance via the remote
5157 protocol's "qXfer:memory-map:read" packet, setting this variable
5158 lets GDB use hardware breakpoints automatically for memory regions
5159 where it can not use software breakpoints. This covers both the
5160 "break" command and internal breakpoints used for other commands
5161 including "next" and "finish".
5164 catch exception unhandled
5165 Stop the program execution when Ada exceptions are raised.
5168 Stop the program execution when an Ada assertion failed.
5172 Set an alternate system root for target files. This is a more
5173 general version of "set solib-absolute-prefix", which is now
5174 an alias to "set sysroot".
5177 Provide extended SPU facility status information. This set of
5178 commands is available only when debugging the Cell/B.E. SPU
5181 * New native configurations
5183 OpenBSD/sh sh*-*openbsd*
5186 unset tdesc filename
5188 Use the specified local file as an XML target description, and do
5189 not query the target for its built-in description.
5193 OpenBSD/sh sh*-*-openbsd*
5194 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5195 Toshiba Media Processor mep-elf
5197 * New remote packets
5200 Ignore the specified signals; pass them directly to the debugged program
5201 without stopping other threads or reporting them to GDB.
5203 qXfer:features:read:
5204 Read an XML target description from the target, which describes its
5209 Read or write contents of an spufs file on the target system. These
5210 packets are available only on the Cell/B.E. SPU architecture.
5212 qXfer:libraries:read:
5213 Report the loaded shared libraries. Combined with new "T" packet
5214 response, this packet allows GDB to debug shared libraries on
5215 targets where the operating system manages the list of loaded
5216 libraries (e.g. Windows and SymbianOS).
5220 Support for these obsolete configurations has been removed.
5228 i[34567]86-*-lynxos*
5229 i[34567]86-*-netware*
5230 i[34567]86-*-sco3.2v5*
5231 i[34567]86-*-sco3.2v4*
5233 i[34567]86-*-sysv4.2*
5236 i[34567]86-*-unixware2*
5237 i[34567]86-*-unixware*
5246 * Other removed features
5253 Various m68k-only ROM monitors.
5260 Various Renesas ROM monitors and debugging interfaces for SH and
5265 Support for a Macraigor serial interface to on-chip debugging.
5266 GDB does not directly support the newer parallel or USB
5271 A debug information format. The predecessor to DWARF 2 and
5272 DWARF 3, which are still supported.
5274 Support for the HP aCC compiler on HP-UX/PA-RISC
5276 SOM-encapsulated symbolic debugging information, automatic
5277 invocation of pxdb, and the aCC custom C++ ABI. This does not
5278 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5279 with aCC can still be debugged on an assembly level.
5281 MIPS ".pdr" sections
5283 A MIPS-specific format used to describe stack frame layout
5284 in debugging information.
5288 GDB could work with an older version of Guile to debug
5289 the interpreter and Scheme programs running in it.
5291 set mips stack-arg-size
5292 set mips saved-gpreg-size
5294 Use "set mips abi" to control parameter passing for MIPS.
5296 *** Changes in GDB 6.6
5301 Cell Broadband Engine SPU spu-elf
5303 * GDB can now be configured as a cross-debugger targeting native Windows
5304 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5305 running on a Windows system over TCP/IP to debug Windows programs.
5307 * The GDB remote stub, gdbserver, has been updated to support Windows and
5308 Cygwin debugging. Both single-threaded and multi-threaded programs are
5311 * The "set trust-readonly-sections" command works again. This command was
5312 broken in GDB 6.3, 6.4, and 6.5.
5314 * The "load" command now supports writing to flash memory, if the remote
5315 stub provides the required support.
5317 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5318 longer requires symbolic debug information (e.g. DWARF-2).
5323 unset substitute-path
5324 show substitute-path
5325 Manage a list of substitution rules that GDB uses to rewrite the name
5326 of the directories where the sources are located. This can be useful
5327 for instance when the sources were moved to a different location
5328 between compilation and debugging.
5332 Print each CLI command as it is executed. Each command is prefixed with
5333 a number of `+' symbols representing the nesting depth.
5334 The source command now has a `-v' option to enable the same feature.
5338 The ARM Demon monitor support (RDP protocol, "target rdp").
5340 Kernel Object Display, an embedded debugging feature which only worked with
5341 an obsolete version of Cisco IOS.
5343 The 'set download-write-size' and 'show download-write-size' commands.
5345 * New remote packets
5348 Tell a stub about GDB client features, and request remote target features.
5349 The first feature implemented is PacketSize, which allows the target to
5350 specify the size of packets it can handle - to minimize the number of
5351 packets required and improve performance when connected to a remote
5355 Fetch an OS auxilliary vector from the remote stub. This packet is a
5356 more efficient replacement for qPart:auxv:read.
5358 qXfer:memory-map:read:
5359 Fetch a memory map from the remote stub, including information about
5360 RAM, ROM, and flash memory devices.
5365 Erase and program a flash memory device.
5367 * Removed remote packets
5370 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5371 used it, and only gdbserver implemented it.
5373 *** Changes in GDB 6.5
5377 Renesas M32C/M16C m32c-elf
5379 Morpho Technologies ms1 ms1-elf
5383 init-if-undefined Initialize a convenience variable, but
5384 only if it doesn't already have a value.
5386 The following commands are presently only implemented for native GNU/Linux:
5388 checkpoint Save a snapshot of the program state.
5390 restart <n> Return the program state to a
5391 previously saved state.
5393 info checkpoints List currently saved checkpoints.
5395 delete-checkpoint <n> Delete a previously saved checkpoint.
5397 set|show detach-on-fork Tell gdb whether to detach from a newly
5398 forked process, or to keep debugging it.
5400 info forks List forks of the user program that
5401 are available to be debugged.
5403 fork <n> Switch to debugging one of several
5404 forks of the user program that are
5405 available to be debugged.
5407 delete-fork <n> Delete a fork from the list of forks
5408 that are available to be debugged (and
5409 kill the forked process).
5411 detach-fork <n> Delete a fork from the list of forks
5412 that are available to be debugged (and
5413 allow the process to continue).
5417 Morpho Technologies ms2 ms1-elf
5419 * Improved Windows host support
5421 GDB now builds as a cross debugger hosted on i686-mingw32, including
5422 native console support, and remote communications using either
5423 network sockets or serial ports.
5425 * Improved Modula-2 language support
5427 GDB can now print most types in the Modula-2 syntax. This includes:
5428 basic types, set types, record types, enumerated types, range types,
5429 pointer types and ARRAY types. Procedure var parameters are correctly
5430 printed and hexadecimal addresses and character constants are also
5431 written in the Modula-2 syntax. Best results can be obtained by using
5432 GNU Modula-2 together with the -gdwarf-2 command line option.
5436 The ARM rdi-share module.
5438 The Netware NLM debug server.
5440 *** Changes in GDB 6.4
5442 * New native configurations
5444 OpenBSD/arm arm*-*-openbsd*
5445 OpenBSD/mips64 mips64-*-openbsd*
5449 Morpho Technologies ms1 ms1-elf
5451 * New command line options
5453 --batch-silent As for --batch, but totally silent.
5454 --return-child-result The debugger will exist with the same value
5455 the child (debugged) program exited with.
5456 --eval-command COMMAND, -ex COMMAND
5457 Execute a single GDB CLI command. This may be
5458 specified multiple times and in conjunction
5459 with the --command (-x) option.
5461 * Deprecated commands removed
5463 The following commands, that were deprecated in 2000, have been
5467 set|show arm disassembly-flavor set|show arm disassembler
5468 othernames set arm disassembler
5469 set|show remotedebug set|show debug remote
5470 set|show archdebug set|show debug arch
5471 set|show eventdebug set|show debug event
5474 * New BSD user-level threads support
5476 It is now possible to debug programs using the user-level threads
5477 library on OpenBSD and FreeBSD. Currently supported (target)
5480 FreeBSD/amd64 x86_64-*-freebsd*
5481 FreeBSD/i386 i386-*-freebsd*
5482 OpenBSD/i386 i386-*-openbsd*
5484 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5485 are not yet supported.
5487 * New support for Matsushita MN10300 w/sim added
5488 (Work in progress). mn10300-elf.
5490 * REMOVED configurations and files
5492 VxWorks and the XDR protocol *-*-vxworks
5493 Motorola MCORE mcore-*-*
5494 National Semiconductor NS32000 ns32k-*-*
5496 * New "set print array-indexes" command
5498 After turning this setting "on", GDB prints the index of each element
5499 when displaying arrays. The default is "off" to preserve the previous
5502 * VAX floating point support
5504 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5506 * User-defined command support
5508 In addition to using $arg0..$arg9 for argument passing, it is now possible
5509 to use $argc to determine now many arguments have been passed. See the
5510 section on user-defined commands in the user manual for more information.
5512 *** Changes in GDB 6.3:
5514 * New command line option
5516 GDB now accepts -l followed by a number to set the timeout for remote
5519 * GDB works with GCC -feliminate-dwarf2-dups
5521 GDB now supports a more compact representation of DWARF-2 debug
5522 information using DW_FORM_ref_addr references. These are produced
5523 by GCC with the option -feliminate-dwarf2-dups and also by some
5524 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5525 to use -feliminate-dwarf2-dups.
5527 * Internationalization
5529 When supported by the host system, GDB will be built with
5530 internationalization (libintl). The task of marking up the sources is
5531 continued, we're looking forward to our first translation.
5535 Initial support for debugging programs compiled with the GNAT
5536 implementation of the Ada programming language has been integrated
5537 into GDB. In this release, support is limited to expression evaluation.
5539 * New native configurations
5541 GNU/Linux/m32r m32r-*-linux-gnu
5545 GDB's remote protocol now includes support for the 'p' packet. This
5546 packet is used to fetch individual registers from a remote inferior.
5548 * END-OF-LIFE registers[] compatibility module
5550 GDB's internal register infrastructure has been completely rewritten.
5551 The new infrastructure making possible the implementation of key new
5552 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5555 GDB 6.3 will be the last release to include the registers[]
5556 compatibility module that allowed out-of-date configurations to
5557 continue to work. This change directly impacts the following
5567 powerpc bdm protocol
5569 Unless there is activity to revive these configurations, they will be
5570 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5572 * OBSOLETE configurations and files
5574 Configurations that have been declared obsolete in this release have
5575 been commented out. Unless there is activity to revive these
5576 configurations, the next release of GDB will have their sources
5577 permanently REMOVED.
5586 *** Changes in GDB 6.2.1:
5588 * MIPS `break main; run' gave an heuristic-fence-post warning
5590 When attempting to run even a simple program, a warning about
5591 heuristic-fence-post being hit would be reported. This problem has
5594 * MIPS IRIX 'long double' crashed GDB
5596 When examining a long double variable, GDB would get a segmentation
5597 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5598 IRIX long double values).
5602 A bug in the VAX stack code was causing problems with the "next"
5603 command. This problem has been fixed.
5605 *** Changes in GDB 6.2:
5607 * Fix for ``many threads''
5609 On GNU/Linux systems that use the NPTL threads library, a program
5610 rapidly creating and deleting threads would confuse GDB leading to the
5613 ptrace: No such process.
5614 thread_db_get_info: cannot get thread info: generic error
5616 This problem has been fixed.
5618 * "-async" and "-noasync" options removed.
5620 Support for the broken "-noasync" option has been removed (it caused
5623 * New ``start'' command.
5625 This command runs the program until the beginning of the main procedure.
5627 * New BSD Kernel Data Access Library (libkvm) interface
5629 Using ``target kvm'' it is now possible to debug kernel core dumps and
5630 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5631 platforms. Currently supported (native-only) configurations are:
5633 FreeBSD/amd64 x86_64-*-freebsd*
5634 FreeBSD/i386 i?86-*-freebsd*
5635 NetBSD/i386 i?86-*-netbsd*
5636 NetBSD/m68k m68*-*-netbsd*
5637 NetBSD/sparc sparc-*-netbsd*
5638 OpenBSD/amd64 x86_64-*-openbsd*
5639 OpenBSD/i386 i?86-*-openbsd*
5640 OpenBSD/m68k m68*-openbsd*
5641 OpenBSD/sparc sparc-*-openbsd*
5643 * Signal trampoline code overhauled
5645 Many generic problems with GDB's signal handling code have been fixed.
5646 These include: backtraces through non-contiguous stacks; recognition
5647 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5648 call; backtrace through a signal trampoline; step into and out of
5649 signal handlers; and single-stepping in the signal trampoline.
5651 Please note that kernel bugs are a limiting factor here. These
5652 features have been shown to work on an s390 GNU/Linux system that
5653 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5655 * Cygwin support for DWARF 2 added.
5657 * New native configurations
5659 GNU/Linux/hppa hppa*-*-linux*
5660 OpenBSD/hppa hppa*-*-openbsd*
5661 OpenBSD/m68k m68*-*-openbsd*
5662 OpenBSD/m88k m88*-*-openbsd*
5663 OpenBSD/powerpc powerpc-*-openbsd*
5664 NetBSD/vax vax-*-netbsd*
5665 OpenBSD/vax vax-*-openbsd*
5667 * END-OF-LIFE frame compatibility module
5669 GDB's internal frame infrastructure has been completely rewritten.
5670 The new infrastructure making it possible to support key new features
5671 including DWARF 2 Call Frame Information. To aid in the task of
5672 migrating old configurations to this new infrastructure, a
5673 compatibility module, that allowed old configurations to continue to
5674 work, was also included.
5676 GDB 6.2 will be the last release to include this frame compatibility
5677 module. This change directly impacts the following configurations:
5687 Unless there is activity to revive these configurations, they will be
5688 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5690 * REMOVED configurations and files
5692 Sun 3, running SunOS 3 m68*-*-sunos3*
5693 Sun 3, running SunOS 4 m68*-*-sunos4*
5694 Sun 2, running SunOS 3 m68000-*-sunos3*
5695 Sun 2, running SunOS 4 m68000-*-sunos4*
5696 Motorola 680x0 running LynxOS m68*-*-lynxos*
5697 AT&T 3b1/Unix pc m68*-att-*
5698 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5699 decstation mips-dec-* mips-little-*
5700 riscos mips-*-riscos* mips-*-sysv*
5701 sonymips mips-sony-*
5702 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5704 *** Changes in GDB 6.1.1:
5706 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5708 The TUI (Text-mode User Interface) is now built as part of a default
5709 GDB configuration. It is enabled by either selecting the TUI with the
5710 command line option "-i=tui" or by running the separate "gdbtui"
5711 program. For more information on the TUI, see the manual "Debugging
5714 * Pending breakpoint support (also included in GDB 6.1)
5716 Support has been added to allow you to specify breakpoints in shared
5717 libraries that have not yet been loaded. If a breakpoint location
5718 cannot be found, and the "breakpoint pending" option is set to auto,
5719 GDB queries you if you wish to make the breakpoint pending on a future
5720 shared-library load. If and when GDB resolves the breakpoint symbol,
5721 the pending breakpoint is removed as one or more regular breakpoints
5724 Pending breakpoints are very useful for GCJ Java debugging.
5726 * Fixed ISO-C build problems
5728 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5729 non ISO-C code that stopped them being built using a more strict ISO-C
5730 compiler (e.g., IBM's C compiler).
5732 * Fixed build problem on IRIX 5
5734 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5735 wasn't able to compile compile on an IRIX 5 system.
5737 * Added execute permission to gdb/gdbserver/configure
5739 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5740 permission. This bug would cause configure to fail on a number of
5741 systems (Solaris, IRIX). Ref: server/519.
5743 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5745 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5746 has been updated to use constant array sizes.
5748 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5750 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5751 its generated DWARF Call Frame Info. This encoding was causing GDB to
5752 panic, that panic has been fixed. Ref: gdb/1628.
5754 * Fixed a problem when examining parameters in shared library code.
5756 When examining parameters in optimized shared library code generated
5757 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5758 not available''. GDB now correctly displays the variable's value.
5760 *** Changes in GDB 6.1:
5762 * Removed --with-mmalloc
5764 Support for the mmalloc memory manager has been removed, as it
5765 conflicted with the internal gdb byte cache.
5767 * Changes in AMD64 configurations
5769 The AMD64 target now includes the %cs and %ss registers. As a result
5770 the AMD64 remote protocol has changed; this affects the floating-point
5771 and SSE registers. If you rely on those registers for your debugging,
5772 you should upgrade gdbserver on the remote side.
5774 * Revised SPARC target
5776 The SPARC target has been completely revised, incorporating the
5777 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5778 support for LynxOS and SunOS 4 has been dropped. Calling functions
5779 from within GDB on operating systems with a non-executable stack
5780 (Solaris, OpenBSD) now works.
5784 GDB has a new C++ demangler which does a better job on the mangled
5785 names generated by current versions of g++. It also runs faster, so
5786 with this and other changes gdb should now start faster on large C++
5789 * DWARF 2 Location Expressions
5791 GDB support for location expressions has been extended to support function
5792 arguments and frame bases. Older versions of GDB could crash when they
5795 * C++ nested types and namespaces
5797 GDB's support for nested types and namespaces in C++ has been
5798 improved, especially if you use the DWARF 2 debugging format. (This
5799 is the default for recent versions of GCC on most platforms.)
5800 Specifically, if you have a class "Inner" defined within a class or
5801 namespace "Outer", then GDB realizes that the class's name is
5802 "Outer::Inner", not simply "Inner". This should greatly reduce the
5803 frequency of complaints about not finding RTTI symbols. In addition,
5804 if you are stopped at inside of a function defined within a namespace,
5805 GDB modifies its name lookup accordingly.
5807 * New native configurations
5809 NetBSD/amd64 x86_64-*-netbsd*
5810 OpenBSD/amd64 x86_64-*-openbsd*
5811 OpenBSD/alpha alpha*-*-openbsd*
5812 OpenBSD/sparc sparc-*-openbsd*
5813 OpenBSD/sparc64 sparc64-*-openbsd*
5815 * New debugging protocols
5817 M32R with SDI protocol m32r-*-elf*
5819 * "set prompt-escape-char" command deleted.
5821 The command "set prompt-escape-char" has been deleted. This command,
5822 and its very obscure effect on GDB's prompt, was never documented,
5823 tested, nor mentioned in the NEWS file.
5825 * OBSOLETE configurations and files
5827 Configurations that have been declared obsolete in this release have
5828 been commented out. Unless there is activity to revive these
5829 configurations, the next release of GDB will have their sources
5830 permanently REMOVED.
5832 Sun 3, running SunOS 3 m68*-*-sunos3*
5833 Sun 3, running SunOS 4 m68*-*-sunos4*
5834 Sun 2, running SunOS 3 m68000-*-sunos3*
5835 Sun 2, running SunOS 4 m68000-*-sunos4*
5836 Motorola 680x0 running LynxOS m68*-*-lynxos*
5837 AT&T 3b1/Unix pc m68*-att-*
5838 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5839 decstation mips-dec-* mips-little-*
5840 riscos mips-*-riscos* mips-*-sysv*
5841 sonymips mips-sony-*
5842 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5844 * REMOVED configurations and files
5846 SGI Irix-4.x mips-sgi-irix4 or iris4
5847 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5848 Z8000 simulator z8k-zilog-none or z8ksim
5849 Matsushita MN10200 w/simulator mn10200-*-*
5850 H8/500 simulator h8500-hitachi-hms or h8500hms
5851 HP/PA running BSD hppa*-*-bsd*
5852 HP/PA running OSF/1 hppa*-*-osf*
5853 HP/PA Pro target hppa*-*-pro*
5854 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5855 386BSD i[3456]86-*-bsd*
5856 Sequent family i[3456]86-sequent-sysv4*
5857 i[3456]86-sequent-sysv*
5858 i[3456]86-sequent-bsd*
5859 SPARC running LynxOS sparc-*-lynxos*
5860 SPARC running SunOS 4 sparc-*-sunos4*
5861 Tsqware Sparclet sparclet-*-*
5862 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5864 *** Changes in GDB 6.0:
5868 Support for debugging the Objective-C programming language has been
5869 integrated into GDB.
5871 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5873 DWARF 2's Call Frame Information makes available compiler generated
5874 information that more exactly describes the program's run-time stack.
5875 By using this information, GDB is able to provide more robust stack
5878 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5879 have been updated to use a new backtrace mechanism which includes
5880 DWARF 2 CFI support.
5884 GDB's remote protocol has been extended to include support for hosted
5885 file I/O (where the remote target uses GDB's file system). See GDB's
5886 remote protocol documentation for details.
5888 * All targets using the new architecture framework.
5890 All of GDB's targets have been updated to use the new internal
5891 architecture framework. The way is now open for future GDB releases
5892 to include cross-architecture native debugging support (i386 on amd64,
5895 * GNU/Linux's Thread Local Storage (TLS)
5897 GDB now includes support for for the GNU/Linux implementation of
5898 per-thread variables.
5900 * GNU/Linux's Native POSIX Thread Library (NPTL)
5902 GDB's thread code has been updated to work with either the new
5903 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
5905 * Separate debug info.
5907 GDB, in conjunction with BINUTILS, now supports a mechanism for
5908 automatically loading debug information from a separate file. Instead
5909 of shipping full debug and non-debug versions of system libraries,
5910 system integrators can now instead ship just the stripped libraries
5911 and optional debug files.
5913 * DWARF 2 Location Expressions
5915 DWARF 2 Location Expressions allow the compiler to more completely
5916 describe the location of variables (even in optimized code) to the
5919 GDB now includes preliminary support for location expressions (support
5920 for DW_OP_piece is still missing).
5924 A number of long standing bugs that caused GDB to die while starting a
5925 Java application have been fixed. GDB's Java support is now
5926 considered "useable".
5928 * GNU/Linux support for fork, vfork, and exec.
5930 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5931 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5934 * GDB supports logging output to a file
5936 There are two new commands, "set logging" and "show logging", which can be
5937 used to capture GDB's output to a file.
5939 * The meaning of "detach" has changed for gdbserver
5941 The "detach" command will now resume the application, as documented. To
5942 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5945 * d10v, m68hc11 `regs' command deprecated
5947 The `info registers' command has been updated so that it displays the
5948 registers using a format identical to the old `regs' command.
5952 A new command, "maint set profile on/off", has been added. This command can
5953 be used to enable or disable profiling while running GDB, to profile a
5954 session or a set of commands. In addition there is a new configure switch,
5955 "--enable-profiling", which will cause GDB to be compiled with profiling
5956 data, for more informative profiling results.
5958 * Default MI syntax changed to "mi2".
5960 The default MI (machine interface) syntax, enabled by the command line
5961 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5962 "mi1", can be enabled by specifying the option "-i=mi1".
5964 Support for the original "mi0" syntax (included in GDB 5.0) has been
5967 Fix for gdb/192: removed extraneous space when displaying frame level.
5968 Fix for gdb/672: update changelist is now output in mi list format.
5969 Fix for gdb/702: a -var-assign that updates the value now shows up
5970 in a subsequent -var-update.
5972 * New native configurations.
5974 FreeBSD/amd64 x86_64-*-freebsd*
5976 * Multi-arched targets.
5978 HP/PA HPUX11 hppa*-*-hpux*
5979 Renesas M32R/D w/simulator m32r-*-elf*
5981 * OBSOLETE configurations and files
5983 Configurations that have been declared obsolete in this release have
5984 been commented out. Unless there is activity to revive these
5985 configurations, the next release of GDB will have their sources
5986 permanently REMOVED.
5988 Z8000 simulator z8k-zilog-none or z8ksim
5989 Matsushita MN10200 w/simulator mn10200-*-*
5990 H8/500 simulator h8500-hitachi-hms or h8500hms
5991 HP/PA running BSD hppa*-*-bsd*
5992 HP/PA running OSF/1 hppa*-*-osf*
5993 HP/PA Pro target hppa*-*-pro*
5994 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5995 Sequent family i[3456]86-sequent-sysv4*
5996 i[3456]86-sequent-sysv*
5997 i[3456]86-sequent-bsd*
5998 Tsqware Sparclet sparclet-*-*
5999 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6001 * REMOVED configurations and files
6004 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6005 IBM AIX PS/2 i[3456]86-*-aix
6006 i386 running Mach 3.0 i[3456]86-*-mach3*
6007 i386 running Mach i[3456]86-*-mach*
6008 i386 running OSF/1 i[3456]86-*osf1mk*
6009 HP/Apollo 68k Family m68*-apollo*-sysv*,
6011 m68*-hp-bsd*, m68*-hp-hpux*
6012 Argonaut Risc Chip (ARC) arc-*-*
6013 Mitsubishi D30V d30v-*-*
6014 Fujitsu FR30 fr30-*-elf*
6015 OS/9000 i[34]86-*-os9k
6016 I960 with MON960 i960-*-coff
6018 * MIPS $fp behavior changed
6020 The convenience variable $fp, for the MIPS, now consistently returns
6021 the address of the current frame's base. Previously, depending on the
6022 context, $fp could refer to either $sp or the current frame's base
6023 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6024 The GNU Source-Level Debugger''.
6026 *** Changes in GDB 5.3:
6028 * GNU/Linux shared library multi-threaded performance improved.
6030 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6031 `/proc', in preference to `ptrace' for memory reads. This may result
6032 in an improvement in the start-up time of multi-threaded, shared
6033 library applications when run under GDB. One GDB user writes: ``loads
6034 shared libs like mad''.
6036 * ``gdbserver'' now supports multi-threaded applications on some targets
6038 Support for debugging multi-threaded applications which use
6039 the GNU/Linux LinuxThreads package has been added for
6040 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6041 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6043 * GDB now supports C/C++ preprocessor macros.
6045 GDB now expands preprocessor macro invocations in C/C++ expressions,
6046 and provides various commands for showing macro definitions and how
6049 The new command `macro expand EXPRESSION' expands any macro
6050 invocations in expression, and shows the result.
6052 The new command `show macro MACRO-NAME' shows the definition of the
6053 macro named MACRO-NAME, and where it was defined.
6055 Most compilers don't include information about macros in the debugging
6056 information by default. In GCC 3.1, for example, you need to compile
6057 your program with the options `-gdwarf-2 -g3'. If the macro
6058 information is present in the executable, GDB will read it.
6060 * Multi-arched targets.
6062 DEC Alpha (partial) alpha*-*-*
6063 DEC VAX (partial) vax-*-*
6065 National Semiconductor NS32000 (partial) ns32k-*-*
6066 Motorola 68000 (partial) m68k-*-*
6067 Motorola MCORE mcore-*-*
6071 Fujitsu FRV architecture added by Red Hat frv*-*-*
6074 * New native configurations
6076 Alpha NetBSD alpha*-*-netbsd*
6077 SH NetBSD sh*-*-netbsdelf*
6078 MIPS NetBSD mips*-*-netbsd*
6079 UltraSPARC NetBSD sparc64-*-netbsd*
6081 * OBSOLETE configurations and files
6083 Configurations that have been declared obsolete in this release have
6084 been commented out. Unless there is activity to revive these
6085 configurations, the next release of GDB will have their sources
6086 permanently REMOVED.
6088 Mitsubishi D30V d30v-*-*
6089 OS/9000 i[34]86-*-os9k
6090 IBM AIX PS/2 i[3456]86-*-aix
6091 Fujitsu FR30 fr30-*-elf*
6092 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6093 Argonaut Risc Chip (ARC) arc-*-*
6094 i386 running Mach 3.0 i[3456]86-*-mach3*
6095 i386 running Mach i[3456]86-*-mach*
6096 i386 running OSF/1 i[3456]86-*osf1mk*
6097 HP/Apollo 68k Family m68*-apollo*-sysv*,
6099 m68*-hp-bsd*, m68*-hp-hpux*
6100 I960 with MON960 i960-*-coff
6102 * OBSOLETE languages
6104 CHILL, a Pascal like language used by telecommunications companies.
6106 * REMOVED configurations and files
6108 AMD 29k family via UDI a29k-amd-udi, udi29k
6109 A29K VxWorks a29k-*-vxworks
6110 AMD 29000 embedded, using EBMON a29k-none-none
6111 AMD 29000 embedded with COFF a29k-none-coff
6112 AMD 29000 embedded with a.out a29k-none-aout
6114 testsuite/gdb.hp/gdb.threads-hp/ directory
6116 * New command "set max-user-call-depth <nnn>"
6118 This command allows the user to limit the call depth of user-defined
6119 commands. The default is 1024.
6121 * Changes in FreeBSD/i386 native debugging.
6123 Support for the "generate-core-file" has been added.
6125 * New commands "dump", "append", and "restore".
6127 These commands allow data to be copied from target memory
6128 to a bfd-format or binary file (dump and append), and back
6129 from a file into memory (restore).
6131 * Improved "next/step" support on multi-processor Alpha Tru64.
6133 The previous single-step mechanism could cause unpredictable problems,
6134 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6135 of a software single-step mechanism prevents this.
6137 *** Changes in GDB 5.2.1:
6145 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6146 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6147 Fix, by Joel Brobecker imported from mainline.
6149 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6150 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6151 Fix, by Fred Fish, imported from mainline.
6153 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6154 Surprisingly enough, it works now.
6155 By Michal Ludvig, imported from mainline.
6157 i386 hardware watchpoint support:
6158 avoid misses on second run for some targets.
6159 By Pierre Muller, imported from mainline.
6161 *** Changes in GDB 5.2:
6163 * New command "set trust-readonly-sections on[off]".
6165 This command is a hint that tells gdb that read-only sections
6166 really are read-only (ie. that their contents will not change).
6167 In this mode, gdb will go to the object file rather than the
6168 target to read memory from read-only sections (such as ".text").
6169 This can be a significant performance improvement on some
6170 (notably embedded) targets.
6172 * New command "generate-core-file" (or "gcore").
6174 This new gdb command allows the user to drop a core file of the child
6175 process state at any time. So far it's been implemented only for
6176 GNU/Linux and Solaris, but should be relatively easily ported to other
6177 hosts. Argument is core file name (defaults to core.<pid>).
6179 * New command line option
6181 GDB now accepts --pid or -p followed by a process id.
6183 * Change in command line behavior -- corefiles vs. process ids.
6185 There is a subtle behavior in the way in which GDB handles
6186 command line arguments. The first non-flag argument is always
6187 a program to debug, but the second non-flag argument may either
6188 be a corefile or a process id. Previously, GDB would attempt to
6189 open the second argument as a corefile, and if that failed, would
6190 issue a superfluous error message and then attempt to attach it as
6191 a process. Now, if the second argument begins with a non-digit,
6192 it will be treated as a corefile. If it begins with a digit,
6193 GDB will attempt to attach it as a process, and if no such process
6194 is found, will then attempt to open it as a corefile.
6196 * Changes in ARM configurations.
6198 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6199 configuration is fully multi-arch.
6201 * New native configurations
6203 ARM NetBSD arm*-*-netbsd*
6204 x86 OpenBSD i[3456]86-*-openbsd*
6205 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6206 Sparc64 running FreeBSD sparc64-*-freebsd*
6210 Sanyo XStormy16 xstormy16-elf
6212 * OBSOLETE configurations and files
6214 Configurations that have been declared obsolete in this release have
6215 been commented out. Unless there is activity to revive these
6216 configurations, the next release of GDB will have their sources
6217 permanently REMOVED.
6219 AMD 29k family via UDI a29k-amd-udi, udi29k
6220 A29K VxWorks a29k-*-vxworks
6221 AMD 29000 embedded, using EBMON a29k-none-none
6222 AMD 29000 embedded with COFF a29k-none-coff
6223 AMD 29000 embedded with a.out a29k-none-aout
6225 testsuite/gdb.hp/gdb.threads-hp/ directory
6227 * REMOVED configurations and files
6229 TI TMS320C80 tic80-*-*
6231 PowerPC Solaris powerpcle-*-solaris*
6232 PowerPC Windows NT powerpcle-*-cygwin32
6233 PowerPC Netware powerpc-*-netware*
6234 Harris/CXUX m88k m88*-harris-cxux*
6235 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6236 ns32k-utek-sysv* ns32k-utek-*
6237 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6238 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6239 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6240 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6241 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6243 * Changes to command line processing
6245 The new `--args' feature can be used to specify command-line arguments
6246 for the inferior from gdb's command line.
6248 * Changes to key bindings
6250 There is a new `operate-and-get-next' function bound to `C-o'.
6252 *** Changes in GDB 5.1.1
6254 Fix compile problem on DJGPP.
6256 Fix a problem with floating-point registers on the i386 being
6259 Fix to stop GDB crashing on .debug_str debug info.
6261 Numerous documentation fixes.
6263 Numerous testsuite fixes.
6265 *** Changes in GDB 5.1:
6267 * New native configurations
6269 Alpha FreeBSD alpha*-*-freebsd*
6270 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6271 MIPS GNU/Linux mips*-*-linux*
6272 MIPS SGI Irix 6.x mips*-sgi-irix6*
6273 ia64 AIX ia64-*-aix*
6274 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6278 Motorola 68HC11 and 68HC12 m68hc11-elf
6280 UltraSparc running GNU/Linux sparc64-*-linux*
6282 * OBSOLETE configurations and files
6284 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6285 Harris/CXUX m88k m88*-harris-cxux*
6286 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6287 ns32k-utek-sysv* ns32k-utek-*
6288 TI TMS320C80 tic80-*-*
6290 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6291 PowerPC Solaris powerpcle-*-solaris*
6292 PowerPC Windows NT powerpcle-*-cygwin32
6293 PowerPC Netware powerpc-*-netware*
6294 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6295 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6296 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6297 Apple Macintosh (MPW) host N/A
6299 stuff.c (Program to stuff files into a specially prepared space in kdb)
6300 kdb-start.c (Main loop for the standalone kernel debugger)
6302 Configurations that have been declared obsolete in this release have
6303 been commented out. Unless there is activity to revive these
6304 configurations, the next release of GDB will have their sources
6305 permanently REMOVED.
6307 * REMOVED configurations and files
6309 Altos 3068 m68*-altos-*
6310 Convex c1-*-*, c2-*-*
6312 ARM RISCix arm-*-* (as host)
6316 * GDB has been converted to ISO C.
6318 GDB's source code has been converted to ISO C. In particular, the
6319 sources are fully protoized, and rely on standard headers being
6324 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6326 * The MI enabled by default.
6328 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6329 revised and enabled by default. Packages which use GDB as a debugging
6330 engine behind a UI or another front end are encouraged to switch to
6331 using the GDB/MI interface, instead of the old annotations interface
6332 which is now deprecated.
6334 * Support for debugging Pascal programs.
6336 GDB now includes support for debugging Pascal programs. The following
6337 main features are supported:
6339 - Pascal-specific data types such as sets;
6341 - automatic recognition of Pascal sources based on file-name
6344 - Pascal-style display of data types, variables, and functions;
6346 - a Pascal expression parser.
6348 However, some important features are not yet supported.
6350 - Pascal string operations are not supported at all;
6352 - there are some problems with boolean types;
6354 - Pascal type hexadecimal constants are not supported
6355 because they conflict with the internal variables format;
6357 - support for Pascal objects and classes is not full yet;
6359 - unlike Pascal, GDB is case-sensitive for symbol names.
6361 * Changes in completion.
6363 Commands such as `shell', `run' and `set args', which pass arguments
6364 to inferior programs, now complete on file names, similar to what
6365 users expect at the shell prompt.
6367 Commands which accept locations, such as `disassemble', `print',
6368 `breakpoint', `until', etc. now complete on filenames as well as
6369 program symbols. Thus, if you type "break foob TAB", and the source
6370 files linked into the programs include `foobar.c', that file name will
6371 be one of the candidates for completion. However, file names are not
6372 considered for completion after you typed a colon that delimits a file
6373 name from a name of a function in that file, as in "break foo.c:bar".
6375 `set demangle-style' completes on available demangling styles.
6377 * New platform-independent commands:
6379 It is now possible to define a post-hook for a command as well as a
6380 hook that runs before the command. For more details, see the
6381 documentation of `hookpost' in the GDB manual.
6383 * Changes in GNU/Linux native debugging.
6385 Support for debugging multi-threaded programs has been completely
6386 revised for all platforms except m68k and sparc. You can now debug as
6387 many threads as your system allows you to have.
6389 Attach/detach is supported for multi-threaded programs.
6391 Support for SSE registers was added for x86. This doesn't work for
6392 multi-threaded programs though.
6394 * Changes in MIPS configurations.
6396 Multi-arch support is enabled for all MIPS configurations.
6398 GDB can now be built as native debugger on SGI Irix 6.x systems for
6399 debugging n32 executables. (Debugging 64-bit executables is not yet
6402 * Unified support for hardware watchpoints in all x86 configurations.
6404 Most (if not all) native x86 configurations support hardware-assisted
6405 breakpoints and watchpoints in a unified manner. This support
6406 implements debug register sharing between watchpoints, which allows to
6407 put a virtually infinite number of watchpoints on the same address,
6408 and also supports watching regions up to 16 bytes with several debug
6411 The new maintenance command `maintenance show-debug-regs' toggles
6412 debugging print-outs in functions that insert, remove, and test
6413 watchpoints and hardware breakpoints.
6415 * Changes in the DJGPP native configuration.
6417 New command ``info dos sysinfo'' displays assorted information about
6418 the CPU, OS, memory, and DPMI server.
6420 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6421 display information about segment descriptors stored in GDT, LDT, and
6424 New commands ``info dos pde'' and ``info dos pte'' display entries
6425 from Page Directory and Page Tables (for now works with CWSDPMI only).
6426 New command ``info dos address-pte'' displays the Page Table entry for
6427 a given linear address.
6429 GDB can now pass command lines longer than 126 characters to the
6430 program being debugged (requires an update to the libdbg.a library
6431 which is part of the DJGPP development kit).
6433 DWARF2 debug info is now supported.
6435 It is now possible to `step' and `next' through calls to `longjmp'.
6437 * Changes in documentation.
6439 All GDB documentation was converted to GFDL, the GNU Free
6440 Documentation License.
6442 Tracepoints-related commands are now fully documented in the GDB
6445 TUI, the Text-mode User Interface, is now documented in the manual.
6447 Tracepoints-related commands are now fully documented in the GDB
6450 The "GDB Internals" manual now has an index. It also includes
6451 documentation of `ui_out' functions, GDB coding standards, x86
6452 hardware watchpoints, and memory region attributes.
6454 * GDB's version number moved to ``version.in''
6456 The Makefile variable VERSION has been replaced by the file
6457 ``version.in''. People creating GDB distributions should update the
6458 contents of this file.
6462 GUD support is now a standard part of the EMACS distribution.
6464 *** Changes in GDB 5.0:
6466 * Improved support for debugging FP programs on x86 targets
6468 Unified and much-improved support for debugging floating-point
6469 programs on all x86 targets. In particular, ``info float'' now
6470 displays the FP registers in the same format on all x86 targets, with
6471 greater level of detail.
6473 * Improvements and bugfixes in hardware-assisted watchpoints
6475 It is now possible to watch array elements, struct members, and
6476 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6477 on x86 targets no longer erroneously trigger when the address is
6480 * Improvements in the native DJGPP version of GDB
6482 The distribution now includes all the scripts and auxiliary files
6483 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6484 machines ``out of the box''.
6486 The DJGPP version can now debug programs that use signals. It is
6487 possible to catch signals that happened in the debuggee, deliver
6488 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6489 would kill the program being debugged.) Programs that hook hardware
6490 interrupts (keyboard, timer, etc.) can also be debugged.
6492 It is now possible to debug DJGPP programs that redirect their
6493 standard handles or switch them to raw (as opposed to cooked) mode, or
6494 even close them. The command ``run < foo > bar'' works as expected,
6495 and ``info terminal'' reports useful information about the debuggee's
6496 terminal, including raw/cooked mode, redirection, etc.
6498 The DJGPP version now uses termios functions for console I/O, which
6499 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6502 DOS-style file names with drive letters are now fully supported by
6505 It is now possible to debug DJGPP programs that switch their working
6506 directory. It is also possible to rerun the debuggee any number of
6507 times without restarting GDB; thus, you can use the same setup,
6508 breakpoints, etc. for many debugging sessions.
6510 * New native configurations
6512 ARM GNU/Linux arm*-*-linux*
6513 PowerPC GNU/Linux powerpc-*-linux*
6517 Motorola MCore mcore-*-*
6518 x86 VxWorks i[3456]86-*-vxworks*
6519 PowerPC VxWorks powerpc-*-vxworks*
6520 TI TMS320C80 tic80-*-*
6522 * OBSOLETE configurations
6524 Altos 3068 m68*-altos-*
6525 Convex c1-*-*, c2-*-*
6527 ARM RISCix arm-*-* (as host)
6530 Configurations that have been declared obsolete will be commented out,
6531 but the code will be left in place. If there is no activity to revive
6532 these configurations before the next release of GDB, the sources will
6533 be permanently REMOVED.
6535 * Gould support removed
6537 Support for the Gould PowerNode and NP1 has been removed.
6539 * New features for SVR4
6541 On SVR4 native platforms (such as Solaris), if you attach to a process
6542 without first loading a symbol file, GDB will now attempt to locate and
6543 load symbols from the running process's executable file.
6545 * Many C++ enhancements
6547 C++ support has been greatly improved. Overload resolution now works properly
6548 in almost all cases. RTTI support is on the way.
6550 * Remote targets can connect to a sub-program
6552 A popen(3) style serial-device has been added. This device starts a
6553 sub-process (such as a stand-alone simulator) and then communicates
6554 with that. The sub-program to run is specified using the syntax
6555 ``|<program> <args>'' vis:
6557 (gdb) set remotedebug 1
6558 (gdb) target extended-remote |mn10300-elf-sim program-args
6560 * MIPS 64 remote protocol
6562 A long standing bug in the mips64 remote protocol where by GDB
6563 expected certain 32 bit registers (ex SR) to be transfered as 32
6564 instead of 64 bits has been fixed.
6566 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6567 added to provide backward compatibility with older versions of GDB.
6569 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6571 The command ``set remotebinarydownload'' command has been replaced by
6572 ``set remote X-packet''. Other commands in ``set remote'' family
6573 include ``set remote P-packet''.
6575 * Breakpoint commands accept ranges.
6577 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6578 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6579 ``tracepoint passcount'' also accepts a range of tracepoints.
6581 * ``apropos'' command added.
6583 The ``apropos'' command searches through command names and
6584 documentation strings, printing out matches, making it much easier to
6585 try to find a command that does what you are looking for.
6589 A new machine oriented interface (MI) has been added to GDB. This
6590 interface is designed for debug environments running GDB as a separate
6591 process. This is part of the long term libGDB project. See the
6592 "GDB/MI" chapter of the GDB manual for further information. It can be
6593 enabled by configuring with:
6595 .../configure --enable-gdbmi
6597 *** Changes in GDB-4.18:
6599 * New native configurations
6601 HP-UX 10.20 hppa*-*-hpux10.20
6602 HP-UX 11.x hppa*-*-hpux11.0*
6603 M68K GNU/Linux m68*-*-linux*
6607 Fujitsu FR30 fr30-*-elf*
6608 Intel StrongARM strongarm-*-*
6609 Mitsubishi D30V d30v-*-*
6611 * OBSOLETE configurations
6613 Gould PowerNode, NP1 np1-*-*, pn-*-*
6615 Configurations that have been declared obsolete will be commented out,
6616 but the code will be left in place. If there is no activity to revive
6617 these configurations before the next release of GDB, the sources will
6618 be permanently REMOVED.
6622 As a compatibility experiment, GDB's source files buildsym.h and
6623 buildsym.c have been converted to pure standard C, no longer
6624 containing any K&R compatibility code. We believe that all systems in
6625 use today either come with a standard C compiler, or have a GCC port
6626 available. If this is not true, please report the affected
6627 configuration to bug-gdb@gnu.org immediately. See the README file for
6628 information about getting a standard C compiler if you don't have one
6633 GDB now uses readline 2.2.
6635 * set extension-language
6637 You can now control the mapping between filename extensions and source
6638 languages by using the `set extension-language' command. For instance,
6639 you can ask GDB to treat .c files as C++ by saying
6640 set extension-language .c c++
6641 The command `info extensions' lists all of the recognized extensions
6642 and their associated languages.
6644 * Setting processor type for PowerPC and RS/6000
6646 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6647 you can use the `set processor' command to specify what variant of the
6648 PowerPC family you are debugging. The command
6652 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6653 following PowerPC and RS6000 variants:
6655 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6656 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6658 403GC IBM PowerPC 403GC
6659 505 Motorola PowerPC 505
6660 860 Motorola PowerPC 860 or 850
6661 601 Motorola PowerPC 601
6662 602 Motorola PowerPC 602
6663 603 Motorola/IBM PowerPC 603 or 603e
6664 604 Motorola PowerPC 604 or 604e
6665 750 Motorola/IBM PowerPC 750 or 750
6667 At the moment, this command just tells GDB what to name the
6668 special-purpose processor registers. Since almost all the affected
6669 registers are inaccessible to user-level programs, this command is
6670 only useful for remote debugging in its present form.
6674 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6675 more extensive support for HP-UX. Added features include shared
6676 library support, kernel threads and hardware watchpoints for 11.00,
6677 support for HP's ANSI C and C++ compilers, and a compatibility mode
6678 for xdb and dbx commands.
6682 HP's donation includes the new concept of catchpoints, which is a
6683 generalization of the old catch command. On HP-UX, it is now possible
6684 to catch exec, fork, and vfork, as well as library loading.
6686 This means that the existing catch command has changed; its first
6687 argument now specifies the type of catch to be set up. See the
6688 output of "help catch" for a list of catchpoint types.
6690 * Debugging across forks
6692 On HP-UX, you can choose which process to debug when a fork() happens
6697 HP has donated a curses-based terminal user interface (TUI). To get
6698 it, build with --enable-tui. Although this can be enabled for any
6699 configuration, at present it only works for native HP debugging.
6701 * GDB remote protocol additions
6703 A new protocol packet 'X' that writes binary data is now available.
6704 Default behavior is to try 'X', then drop back to 'M' if the stub
6705 fails to respond. The settable variable `remotebinarydownload'
6706 allows explicit control over the use of 'X'.
6708 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6709 full 64-bit address. The command
6711 set remoteaddresssize 32
6713 can be used to revert to the old behaviour. For existing remote stubs
6714 the change should not be noticed, as the additional address information
6717 In order to assist in debugging stubs, you may use the maintenance
6718 command `packet' to send any text string to the stub. For instance,
6720 maint packet heythere
6722 sends the packet "$heythere#<checksum>". Note that it is very easy to
6723 disrupt a debugging session by sending the wrong packet at the wrong
6726 The compare-sections command allows you to compare section data on the
6727 target to what is in the executable file without uploading or
6728 downloading, by comparing CRC checksums.
6730 * Tracing can collect general expressions
6732 You may now collect general expressions at tracepoints. This requires
6733 further additions to the target-side stub; see tracepoint.c and
6734 doc/agentexpr.texi for further details.
6736 * mask-address variable for Mips
6738 For Mips targets, you may control the zeroing of the upper 32 bits of
6739 a 64-bit address by entering `set mask-address on'. This is mainly
6740 of interest to users of embedded R4xxx and R5xxx processors.
6742 * Higher serial baud rates
6744 GDB's serial code now allows you to specify baud rates 57600, 115200,
6745 230400, and 460800 baud. (Note that your host system may not be able
6746 to achieve all of these rates.)
6750 The i960 configuration now includes an initial implementation of a
6751 builtin simulator, contributed by Jim Wilson.
6754 *** Changes in GDB-4.17:
6756 * New native configurations
6758 Alpha GNU/Linux alpha*-*-linux*
6759 Unixware 2.x i[3456]86-unixware2*
6760 Irix 6.x mips*-sgi-irix6*
6761 PowerPC GNU/Linux powerpc-*-linux*
6762 PowerPC Solaris powerpcle-*-solaris*
6763 Sparc GNU/Linux sparc-*-linux*
6764 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6768 Argonaut Risc Chip (ARC) arc-*-*
6769 Hitachi H8/300S h8300*-*-*
6770 Matsushita MN10200 w/simulator mn10200-*-*
6771 Matsushita MN10300 w/simulator mn10300-*-*
6772 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6773 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6774 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6775 Mitsubishi D10V w/simulator d10v-*-*
6776 Mitsubishi M32R/D w/simulator m32r-*-elf*
6777 Tsqware Sparclet sparclet-*-*
6778 NEC V850 w/simulator v850-*-*
6780 * New debugging protocols
6782 ARM with RDI protocol arm*-*-*
6783 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6784 DDB and LSI variants of PMON protocol mips*-*-*
6785 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6786 PowerPC with SDS protocol powerpc{,le}-*-eabi
6787 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6791 All configurations can now understand and use the DWARF 2 debugging
6792 format. The choice is automatic, if the symbol file contains DWARF 2
6797 GDB now includes basic Java language support. This support is
6798 only useful with Java compilers that produce native machine code.
6800 * solib-absolute-prefix and solib-search-path
6802 For SunOS and SVR4 shared libraries, you may now set the prefix for
6803 loading absolute shared library symbol files, and the search path for
6804 locating non-absolute shared library symbol files.
6806 * Live range splitting
6808 GDB can now effectively debug code for which GCC has performed live
6809 range splitting as part of its optimization. See gdb/doc/LRS for
6810 more details on the expected format of the stabs information.
6814 GDB's support for the GNU Hurd, including thread debugging, has been
6815 updated to work with current versions of the Hurd.
6819 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6820 instruction set. ARM GDB automatically detects when Thumb
6821 instructions are in use, and adjusts disassembly and backtracing
6826 GDB's MIPS target configurations now handle the MIP16 16-bit
6831 GDB now includes support for overlays; if an executable has been
6832 linked such that multiple sections are based at the same address, GDB
6833 will decide which section to use for symbolic info. You can choose to
6834 control the decision manually, using overlay commands, or implement
6835 additional target-side support and use "overlay load-target" to bring
6836 in the overlay mapping. Do "help overlay" for more detail.
6840 The command "info symbol <address>" displays information about
6841 the symbol at the specified address.
6845 The standard remote protocol now includes an extension that allows
6846 asynchronous collection and display of trace data. This requires
6847 extensive support in the target-side debugging stub. Tracing mode
6848 includes a new interaction mode in GDB and new commands: see the
6849 file tracepoint.c for more details.
6853 Configurations for embedded MIPS now include a simulator contributed
6854 by Cygnus Solutions. The simulator supports the instruction sets
6855 of most MIPS variants.
6859 Sparc configurations may now include the ERC32 simulator contributed
6860 by the European Space Agency. The simulator is not built into
6861 Sparc targets by default; configure with --enable-sim to include it.
6865 For target configurations that may include multiple variants of a
6866 basic architecture (such as MIPS and SH), you may now set the
6867 architecture explicitly. "set arch" sets, "info arch" lists
6868 the possible architectures.
6870 *** Changes in GDB-4.16:
6872 * New native configurations
6874 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6875 M68K NetBSD m68k-*-netbsd*
6876 PowerPC AIX 4.x powerpc-*-aix*
6877 PowerPC MacOS powerpc-*-macos*
6878 PowerPC Windows NT powerpcle-*-cygwin32
6879 RS/6000 AIX 4.x rs6000-*-aix4*
6883 ARM with RDP protocol arm-*-*
6884 I960 with MON960 i960-*-coff
6885 MIPS VxWorks mips*-*-vxworks*
6886 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6887 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6889 Matra Sparclet sparclet-*-*
6893 The powerpc-eabi configuration now includes the PSIM simulator,
6894 contributed by Andrew Cagney, with assistance from Mike Meissner.
6895 PSIM is a very elaborate model of the PowerPC, including not only
6896 basic instruction set execution, but also details of execution unit
6897 performance and I/O hardware. See sim/ppc/README for more details.
6901 GDB now works with Solaris 2.5.
6903 * Windows 95/NT native
6905 GDB will now work as a native debugger on Windows 95 and Windows NT.
6906 To build it from source, you must use the "gnu-win32" environment,
6907 which uses a DLL to emulate enough of Unix to run the GNU tools.
6908 Further information, binaries, and sources are available at
6909 ftp.cygnus.com, under pub/gnu-win32.
6911 * dont-repeat command
6913 If a user-defined command includes the command `dont-repeat', then the
6914 command will not be repeated if the user just types return. This is
6915 useful if the command is time-consuming to run, so that accidental
6916 extra keystrokes don't run the same command many times.
6918 * Send break instead of ^C
6920 The standard remote protocol now includes an option to send a break
6921 rather than a ^C to the target in order to interrupt it. By default,
6922 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
6924 * Remote protocol timeout
6926 The standard remote protocol includes a new variable `remotetimeout'
6927 that allows you to set the number of seconds before GDB gives up trying
6928 to read from the target. The default value is 2.
6930 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6932 By default GDB will automatically keep track of objects as they are
6933 loaded and unloaded by the dynamic linker. By using the command `set
6934 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6935 when shared library events occur, thus allowing you to set breakpoints
6936 in shared libraries which are explicitly loaded by the inferior.
6938 Note this feature does not work on hpux8. On hpux9 you must link
6939 /usr/lib/end.o into your program. This feature should work
6940 automatically on hpux10.
6942 * Irix 5.x hardware watchpoint support
6944 Irix 5 configurations now support the use of hardware watchpoints.
6946 * Mips protocol "SYN garbage limit"
6948 When debugging a Mips target using the `target mips' protocol, you
6949 may set the number of characters that GDB will ignore by setting
6950 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6951 every character. The default value is 1050.
6953 * Recording and replaying remote debug sessions
6955 If you set `remotelogfile' to the name of a file, gdb will write to it
6956 a recording of a remote debug session. This recording may then be
6957 replayed back to gdb using "gdbreplay". See gdbserver/README for
6958 details. This is useful when you have a problem with GDB while doing
6959 remote debugging; you can make a recording of the session and send it
6960 to someone else, who can then recreate the problem.
6962 * Speedups for remote debugging
6964 GDB includes speedups for downloading and stepping MIPS systems using
6965 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6966 and more efficient S-record downloading.
6968 * Memory use reductions and statistics collection
6970 GDB now uses less memory and reports statistics about memory usage.
6971 Try the `maint print statistics' command, for example.
6973 *** Changes in GDB-4.15:
6975 * Psymtabs for XCOFF
6977 The symbol reader for AIX GDB now uses partial symbol tables. This
6978 can greatly improve startup time, especially for large executables.
6980 * Remote targets use caching
6982 Remote targets now use a data cache to speed up communication with the
6983 remote side. The data cache could lead to incorrect results because
6984 it doesn't know about volatile variables, thus making it impossible to
6985 debug targets which use memory mapped I/O devices. `set remotecache
6986 off' turns the data cache off.
6988 * Remote targets may have threads
6990 The standard remote protocol now includes support for multiple threads
6991 in the target system, using new protocol commands 'H' and 'T'. See
6992 gdb/remote.c for details.
6996 If GDB is configured with `--enable-netrom', then it will include
6997 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6998 acts as though it is a bank of ROM on the target board, but you can
6999 write into it over the network. GDB's support consists only of
7000 support for fast loading into the emulated ROM; to debug, you must use
7001 another protocol, such as standard remote protocol. The usual
7002 sequence is something like
7004 target nrom <netrom-hostname>
7006 target remote <netrom-hostname>:1235
7010 GDB now includes support for the Apple Macintosh, as a host only. It
7011 may be run as either an MPW tool or as a standalone application, and
7012 it can debug through the serial port. All the usual GDB commands are
7013 available, but to the target command, you must supply "serial" as the
7014 device type instead of "/dev/ttyXX". See mpw-README in the main
7015 directory for more information on how to build. The MPW configuration
7016 scripts */mpw-config.in support only a few targets, and only the
7017 mips-idt-ecoff target has been tested.
7021 GDB configuration now uses autoconf. This is not user-visible,
7022 but does simplify configuration and building.
7026 GDB now supports hpux10.
7028 *** Changes in GDB-4.14:
7030 * New native configurations
7032 x86 FreeBSD i[345]86-*-freebsd
7033 x86 NetBSD i[345]86-*-netbsd
7034 NS32k NetBSD ns32k-*-netbsd
7035 Sparc NetBSD sparc-*-netbsd
7039 A29K VxWorks a29k-*-vxworks
7040 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7041 CPU32 EST-300 emulator m68*-*-est*
7042 PowerPC ELF powerpc-*-elf
7045 * Alpha OSF/1 support for procfs
7047 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7048 possible to attach to running processes. As the mounting of the /proc
7049 filesystem is optional on the Alpha, GDB automatically determines
7050 the availability of /proc during startup. This can lead to problems
7051 if /proc is unmounted after GDB has been started.
7053 * Arguments to user-defined commands
7055 User commands may accept up to 10 arguments separated by whitespace.
7056 Arguments are accessed within the user command via $arg0..$arg9. A
7059 print $arg0 + $arg1 + $arg2
7061 To execute the command use:
7064 Defines the command "adder" which prints the sum of its three arguments.
7065 Note the arguments are text substitutions, so they may reference variables,
7066 use complex expressions, or even perform inferior function calls.
7068 * New `if' and `while' commands
7070 This makes it possible to write more sophisticated user-defined
7071 commands. Both commands take a single argument, which is the
7072 expression to evaluate, and must be followed by the commands to
7073 execute, one per line, if the expression is nonzero, the list being
7074 terminated by the word `end'. The `if' command list may include an
7075 `else' word, which causes the following commands to be executed only
7076 if the expression is zero.
7078 * Fortran source language mode
7080 GDB now includes partial support for Fortran 77. It will recognize
7081 Fortran programs and can evaluate a subset of Fortran expressions, but
7082 variables and functions may not be handled correctly. GDB will work
7083 with G77, but does not yet know much about symbols emitted by other
7086 * Better HPUX support
7088 Most debugging facilities now work on dynamic executables for HPPAs
7089 running hpux9 or later. You can attach to running dynamically linked
7090 processes, but by default the dynamic libraries will be read-only, so
7091 for instance you won't be able to put breakpoints in them. To change
7092 that behavior do the following before running the program:
7098 This will cause the libraries to be mapped private and read-write.
7099 To revert to the normal behavior, do this:
7105 You cannot set breakpoints or examine data in the library until after
7106 the library is loaded if the function/data symbols do not have
7109 GDB can now also read debug symbols produced by the HP C compiler on
7110 HPPAs (sorry, no C++, Fortran or 68k support).
7112 * Target byte order now dynamically selectable
7114 You can choose which byte order to use with a target system, via the
7115 commands "set endian big" and "set endian little", and you can see the
7116 current setting by using "show endian". You can also give the command
7117 "set endian auto", in which case GDB will use the byte order
7118 associated with the executable. Currently, only embedded MIPS
7119 configurations support dynamic selection of target byte order.
7121 * New DOS host serial code
7123 This version uses DPMI interrupts to handle buffered I/O, so you
7124 no longer need to run asynctsr when debugging boards connected to
7127 *** Changes in GDB-4.13:
7129 * New "complete" command
7131 This lists all the possible completions for the rest of the line, if it
7132 were to be given as a command itself. This is intended for use by emacs.
7134 * Trailing space optional in prompt
7136 "set prompt" no longer adds a space for you after the prompt you set. This
7137 allows you to set a prompt which ends in a space or one that does not.
7139 * Breakpoint hit counts
7141 "info break" now displays a count of the number of times the breakpoint
7142 has been hit. This is especially useful in conjunction with "ignore"; you
7143 can ignore a large number of breakpoint hits, look at the breakpoint info
7144 to see how many times the breakpoint was hit, then run again, ignoring one
7145 less than that number, and this will get you quickly to the last hit of
7148 * Ability to stop printing at NULL character
7150 "set print null-stop" will cause GDB to stop printing the characters of
7151 an array when the first NULL is encountered. This is useful when large
7152 arrays actually contain only short strings.
7154 * Shared library breakpoints
7156 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7157 breakpoints in shared libraries before the executable is run.
7159 * Hardware watchpoints
7161 There is a new hardware breakpoint for the watch command for sparclite
7162 targets. See gdb/sparclite/hw_breakpoint.note.
7164 Hardware watchpoints are also now supported under GNU/Linux.
7168 Annotations have been added. These are for use with graphical interfaces,
7169 and are still experimental. Currently only gdba.el uses these.
7171 * Improved Irix 5 support
7173 GDB now works properly with Irix 5.2.
7175 * Improved HPPA support
7177 GDB now works properly with the latest GCC and GAS.
7179 * New native configurations
7181 Sequent PTX4 i[34]86-sequent-ptx4
7182 HPPA running OSF/1 hppa*-*-osf*
7183 Atari TT running SVR4 m68*-*-sysv4*
7184 RS/6000 LynxOS rs6000-*-lynxos*
7188 OS/9000 i[34]86-*-os9k
7189 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7192 * Hitachi SH7000 and E7000-PC ICE support
7194 There is now support for communicating with the Hitachi E7000-PC ICE.
7195 This is available automatically when GDB is configured for the SH.
7199 As usual, a variety of small fixes and improvements, both generic
7200 and configuration-specific. See the ChangeLog for more detail.
7202 *** Changes in GDB-4.12:
7204 * Irix 5 is now supported
7208 GDB-4.12 on the HPPA has a number of changes which make it unable
7209 to debug the output from the currently released versions of GCC and
7210 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7211 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7212 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7215 *** Changes in GDB-4.11:
7217 * User visible changes:
7221 The "set remotedebug" option is now consistent between the mips remote
7222 target, remote targets using the gdb-specific protocol, UDI (AMD's
7223 debug protocol for the 29k) and the 88k bug monitor. It is now an
7224 integer specifying a debug level (normally 0 or 1, but 2 means more
7225 debugging info for the mips target).
7227 * DEC Alpha native support
7229 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7230 debug info, but GDB works fairly well with the DEC compiler and should
7231 work with a future GCC release. See the README file for a few
7232 Alpha-specific notes.
7234 * Preliminary thread implementation
7236 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7238 * LynxOS native and target support for 386
7240 This release has been hosted on LynxOS 2.2, and also can be configured
7241 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7244 * Improvements in C++ mangling/demangling.
7246 This release has much better g++ debugging, specifically in name
7247 mangling/demangling, virtual function calls, print virtual table,
7248 call methods, ...etc.
7250 *** Changes in GDB-4.10:
7252 * User visible changes:
7254 Remote debugging using the GDB-specific (`target remote') protocol now
7255 supports the `load' command. This is only useful if you have some
7256 other way of getting the stub to the target system, and you can put it
7257 somewhere in memory where it won't get clobbered by the download.
7259 Filename completion now works.
7261 When run under emacs mode, the "info line" command now causes the
7262 arrow to point to the line specified. Also, "info line" prints
7263 addresses in symbolic form (as well as hex).
7265 All vxworks based targets now support a user settable option, called
7266 vxworks-timeout. This option represents the number of seconds gdb
7267 should wait for responses to rpc's. You might want to use this if
7268 your vxworks target is, perhaps, a slow software simulator or happens
7269 to be on the far side of a thin network line.
7273 This release contains support for using a DEC alpha as a GDB host for
7274 cross debugging. Native alpha debugging is not supported yet.
7277 *** Changes in GDB-4.9:
7281 This is the first GDB release which is accompanied by a matching testsuite.
7282 The testsuite requires installation of dejagnu, which should be available
7283 via ftp from most sites that carry GNU software.
7287 'Cfront' style demangling has had its name changed to 'ARM' style, to
7288 emphasize that it was written from the specifications in the C++ Annotated
7289 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7290 disclaimers, it still generated too much confusion with users attempting to
7291 use gdb with AT&T cfront.
7295 GDB now uses a standard remote interface to a simulator library.
7296 So far, the library contains simulators for the Zilog Z8001/2, the
7297 Hitachi H8/300, H8/500 and Super-H.
7299 * New targets supported
7301 H8/300 simulator h8300-hitachi-hms or h8300hms
7302 H8/500 simulator h8500-hitachi-hms or h8500hms
7303 SH simulator sh-hitachi-hms or sh
7304 Z8000 simulator z8k-zilog-none or z8ksim
7305 IDT MIPS board over serial line mips-idt-ecoff
7307 Cross-debugging to GO32 targets is supported. It requires a custom
7308 version of the i386-stub.c module which is integrated with the
7309 GO32 memory extender.
7311 * New remote protocols
7313 MIPS remote debugging protocol.
7315 * New source languages supported
7317 This version includes preliminary support for Chill, a Pascal like language
7318 used by telecommunications companies. Chill support is also being integrated
7319 into the GNU compiler, but we don't know when it will be publically available.
7322 *** Changes in GDB-4.8:
7324 * HP Precision Architecture supported
7326 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7327 version of this support was available as a set of patches from the
7328 University of Utah. GDB does not support debugging of programs
7329 compiled with the HP compiler, because HP will not document their file
7330 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7331 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7333 Many problems in the preliminary version have been fixed.
7335 * Faster and better demangling
7337 We have improved template demangling and fixed numerous bugs in the GNU style
7338 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7339 character types (wchar_t) are now supported. Demangling of each symbol is now
7340 only done once, and is cached when the symbol table for a file is read in.
7341 This results in a small increase in memory usage for C programs, a moderate
7342 increase in memory usage for C++ programs, and a fantastic speedup in
7345 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7346 from the specifications in the Annotated Reference Manual, which AT&T's
7347 compiler does not actually implement.
7349 * G++ multiple inheritance compiler problem
7351 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7352 inheritance lattices was reworked to properly discover ambiguities. We
7353 recently found an example which causes this new algorithm to fail in a
7354 very subtle way, producing bad debug information for those classes.
7355 The file 'gcc.patch' (in this directory) can be applied to gcc to
7356 circumvent the problem. A future GCC release will contain a complete
7359 The previous G++ debug info problem (mentioned below for the gdb-4.7
7360 release) is fixed in gcc version 2.3.2.
7362 * Improved configure script
7364 The `configure' script will now attempt to guess your system type if
7365 you don't supply a host system type. The old scheme of supplying a
7366 host system triplet is preferable over using this. All the magic is
7367 done in the new `config.guess' script. Examine it for details.
7369 We have also brought our configure script much more in line with the FSF's
7370 version. It now supports the --with-xxx options. In particular,
7371 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7372 The resulting GDB will not be able to read arbitrary object file formats --
7373 only the format ``expected'' to be used on the configured target system.
7374 We hope to make this the default in a future release.
7376 * Documentation improvements
7378 There's new internal documentation on how to modify GDB, and how to
7379 produce clean changes to the code. We implore people to read it
7380 before submitting changes.
7382 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7383 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7384 `info' files are also provided. To build `info' files from scratch,
7385 you will need the latest `makeinfo' release, which will be available in
7386 a future texinfo-X.Y release.
7388 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7389 We're not sure exactly which versions have this problem, but it has
7390 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7391 or better. If that isn't possible, there is a patch in
7392 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7393 around this problem.
7397 GDB now supports array constants that can be used in expressions typed in by
7398 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7399 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7402 The new directory `gdb/sparclite' contains a program that demonstrates
7403 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7405 * New native hosts supported
7407 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7408 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7410 * New targets supported
7412 AMD 29k family via UDI a29k-amd-udi or udi29k
7414 * New file formats supported
7416 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7417 HPUX core files, and SCO 3.2v2 core files.
7421 Attaching to processes now works again; thanks for the many bug reports.
7423 We have also stomped on a bunch of core dumps caused by
7424 printf_filtered("%s") problems.
7426 We eliminated a copyright problem on the rpc and ptrace header files
7427 for VxWorks, which was discovered at the last minute during the 4.7
7428 release. You should now be able to build a VxWorks GDB.
7430 You can now interrupt gdb while an attached process is running. This
7431 will cause the attached process to stop, and give control back to GDB.
7433 We fixed problems caused by using too many file descriptors
7434 for reading symbols from object files and libraries. This was
7435 especially a problem for programs that used many (~100) shared
7438 The `step' command now only enters a subroutine if there is line number
7439 information for the subroutine. Otherwise it acts like the `next'
7440 command. Previously, `step' would enter subroutines if there was
7441 any debugging information about the routine. This avoids problems
7442 when using `cc -g1' on MIPS machines.
7444 * Internal improvements
7446 GDB's internal interfaces have been improved to make it easier to support
7447 debugging of multiple languages in the future.
7449 GDB now uses a common structure for symbol information internally.
7450 Minimal symbols (derived from linkage symbols in object files), partial
7451 symbols (from a quick scan of debug information), and full symbols
7452 contain a common subset of information, making it easier to write
7453 shared code that handles any of them.
7455 * New command line options
7457 We now accept --silent as an alias for --quiet.
7461 The memory-mapped-malloc library is now licensed under the GNU Library
7462 General Public License.
7464 *** Changes in GDB-4.7:
7466 * Host/native/target split
7468 GDB has had some major internal surgery to untangle the support for
7469 hosts and remote targets. Now, when you configure GDB for a remote
7470 target, it will no longer load in all of the support for debugging
7471 local programs on the host. When fully completed and tested, this will
7472 ensure that arbitrary host/target combinations are possible.
7474 The primary conceptual shift is to separate the non-portable code in
7475 GDB into three categories. Host specific code is required any time GDB
7476 is compiled on that host, regardless of the target. Target specific
7477 code relates to the peculiarities of the target, but can be compiled on
7478 any host. Native specific code is everything else: it can only be
7479 built when the host and target are the same system. Child process
7480 handling and core file support are two common `native' examples.
7482 GDB's use of /proc for controlling Unix child processes is now cleaner.
7483 It has been split out into a single module under the `target_ops' vector,
7484 plus two native-dependent functions for each system that uses /proc.
7486 * New hosts supported
7488 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7489 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7490 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7492 * New targets supported
7494 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7495 68030 and CPU32 m68030-*-*, m68332-*-*
7497 * New native hosts supported
7499 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7500 (386bsd is not well tested yet)
7501 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7503 * New file formats supported
7505 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7506 supports reading of `a.out.adobe' object files, which are an a.out
7507 format extended with minimal information about multiple sections.
7511 `show copying' is the same as the old `info copying'.
7512 `show warranty' is the same as `info warrantee'.
7513 These were renamed for consistency. The old commands continue to work.
7515 `info handle' is a new alias for `info signals'.
7517 You can now define pre-command hooks, which attach arbitrary command
7518 scripts to any command. The commands in the hook will be executed
7519 prior to the user's command. You can also create a hook which will be
7520 executed whenever the program stops. See gdb.texinfo.
7524 We now deal with Cfront style name mangling, and can even extract type
7525 info from mangled symbols. GDB can automatically figure out which
7526 symbol mangling style your C++ compiler uses.
7528 Calling of methods and virtual functions has been improved as well.
7532 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7533 fixed. This was due to mishandling of the extra N_SO stabs output
7536 We also finally got Ultrix 4.2 running in house, and fixed core file
7537 support, with help from a dozen people on the net.
7539 John M. Farrell discovered that the reason that single-stepping was so
7540 slow on all of the Mips based platforms (primarily SGI and DEC) was
7541 that we were trying to demangle and lookup a symbol used for internal
7542 purposes on every instruction that was being stepped through. Changing
7543 the name of that symbol so that it couldn't be mistaken for a C++
7544 mangled symbol sped things up a great deal.
7546 Rich Pixley sped up symbol lookups in general by getting much smarter
7547 about when C++ symbol mangling is necessary. This should make symbol
7548 completion (TAB on the command line) much faster. It's not as fast as
7549 we'd like, but it's significantly faster than gdb-4.6.
7553 A new user controllable variable 'call_scratch_address' can
7554 specify the location of a scratch area to be used when GDB
7555 calls a function in the target. This is necessary because the
7556 usual method of putting the scratch area on the stack does not work
7557 in systems that have separate instruction and data spaces.
7559 We integrated changes to support the 29k UDI (Universal Debugger
7560 Interface), but discovered at the last minute that we didn't have all
7561 of the appropriate copyright paperwork. We are working with AMD to
7562 resolve this, and hope to have it available soon.
7566 We have sped up the remote serial line protocol, especially for targets
7567 with lots of registers. It now supports a new `expedited status' ('T')
7568 message which can be used in place of the existing 'S' status message.
7569 This allows the remote stub to send only the registers that GDB
7570 needs to make a quick decision about single-stepping or conditional
7571 breakpoints, eliminating the need to fetch the entire register set for
7572 each instruction being stepped through.
7574 The GDB remote serial protocol now implements a write-through cache for
7575 registers, only re-reading the registers if the target has run.
7577 There is also a new remote serial stub for SPARC processors. You can
7578 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7579 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7580 processor with a serial port.
7584 Configure.in files have become much easier to read and modify. A new
7585 `table driven' format makes it more obvious what configurations are
7586 supported, and what files each one uses.
7590 There is a new opcodes library which will eventually contain all of the
7591 disassembly routines and opcode tables. At present, it only contains
7592 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7593 disassembler (binutils/objdump) to share these routines.
7595 The libiberty library is now copylefted under the GNU Library General
7596 Public License. This allows more liberal use, and was done so libg++
7597 can use it. This makes no difference to GDB, since the Library License
7598 grants all the rights from the General Public License.
7602 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7603 reference to the stabs symbol info used by the debugger. It is (as far
7604 as we know) the only published document on this fascinating topic. We
7605 encourage you to read it, compare it to the stabs information on your
7606 system, and send improvements on the document in general (to
7607 bug-gdb@prep.ai.mit.edu).
7609 And, of course, many bugs have been fixed.
7612 *** Changes in GDB-4.6:
7614 * Better support for C++ function names
7616 GDB now accepts as input the "demangled form" of C++ overloaded function
7617 names and member function names, and can do command completion on such names
7618 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7619 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7620 Make use of command completion, it is your friend.
7622 GDB also now accepts a variety of C++ mangled symbol formats. They are
7623 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7624 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7625 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7626 for the list of formats.
7628 * G++ symbol mangling problem
7630 Recent versions of gcc have a bug in how they emit debugging information for
7631 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7632 directory) can be applied to gcc to fix the problem. Alternatively, if you
7633 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7634 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7635 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7638 * New 'maintenance' command
7640 All of the commands related to hacking GDB internals have been moved out of
7641 the main command set, and now live behind the 'maintenance' command. This
7642 can also be abbreviated as 'mt'. The following changes were made:
7644 dump-me -> maintenance dump-me
7645 info all-breakpoints -> maintenance info breakpoints
7646 printmsyms -> maintenance print msyms
7647 printobjfiles -> maintenance print objfiles
7648 printpsyms -> maintenance print psymbols
7649 printsyms -> maintenance print symbols
7651 The following commands are new:
7653 maintenance demangle Call internal GDB demangler routine to
7654 demangle a C++ link name and prints the result.
7655 maintenance print type Print a type chain for a given symbol
7657 * Change to .gdbinit file processing
7659 We now read the $HOME/.gdbinit file before processing the argv arguments
7660 (e.g. reading symbol files or core files). This allows global parameters to
7661 be set, which will apply during the symbol reading. The ./.gdbinit is still
7662 read after argv processing.
7664 * New hosts supported
7666 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7668 GNU/Linux support i386-unknown-linux or linux
7670 We are also including code to support the HP/PA running BSD and HPUX. This
7671 is almost guaranteed not to work, as we didn't have time to test or build it
7672 for this release. We are including it so that the more adventurous (or
7673 masochistic) of you can play with it. We also had major problems with the
7674 fact that the compiler that we got from HP doesn't support the -g option.
7677 * New targets supported
7679 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7681 * More smarts about finding #include files
7683 GDB now remembers the compilation directory for all include files, and for
7684 all files from which C is generated (like yacc and lex sources). This
7685 greatly improves GDB's ability to find yacc/lex sources, and include files,
7686 especially if you are debugging your program from a directory different from
7687 the one that contains your sources.
7689 We also fixed a bug which caused difficulty with listing and setting
7690 breakpoints in include files which contain C code. (In the past, you had to
7691 try twice in order to list an include file that you hadn't looked at before.)
7693 * Interesting infernals change
7695 GDB now deals with arbitrary numbers of sections, where the symbols for each
7696 section must be relocated relative to that section's landing place in the
7697 target's address space. This work was needed to support ELF with embedded
7698 stabs used by Solaris-2.0.
7700 * Bug fixes (of course!)
7702 There have been loads of fixes for the following things:
7703 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7704 i960, stabs, DOS(GO32), procfs, etc...
7706 See the ChangeLog for details.
7708 *** Changes in GDB-4.5:
7710 * New machines supported (host and target)
7712 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7714 SGI Irix-4.x mips-sgi-irix4 or iris4
7716 * New malloc package
7718 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7719 Mmalloc is capable of handling multiple heaps of memory. It is also
7720 capable of saving a heap to a file, and then mapping it back in later.
7721 This can be used to greatly speedup the startup of GDB by using a
7722 pre-parsed symbol table which lives in a mmalloc managed heap. For
7723 more details, please read mmalloc/mmalloc.texi.
7727 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7728 'help info proc' for details.
7730 * MIPS ecoff symbol table format
7732 The code that reads MIPS symbol table format is now supported on all hosts.
7733 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7736 * File name changes for MS-DOS
7738 Many files in the config directories have been renamed to make it easier to
7739 support GDB on MS-DOSe systems (which have very restrictive file name
7740 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7741 environment) is close to working but has some remaining problems. Note
7742 that debugging of DOS programs is not supported, due to limitations
7743 in the ``operating system'', but it can be used to host cross-debugging.
7745 * Cross byte order fixes
7747 Many fixes have been made to support cross debugging of Sparc and MIPS
7748 targets from hosts whose byte order differs.
7750 * New -mapped and -readnow options
7752 If memory-mapped files are available on your system through the 'mmap'
7753 system call, you can use the -mapped option on the `file' or
7754 `symbol-file' commands to cause GDB to write the symbols from your
7755 program into a reusable file. If the program you are debugging is
7756 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7757 Future GDB debugging sessions will notice the presence of this file,
7758 and will quickly map in symbol information from it, rather than reading
7759 the symbol table from the executable program. Using the '-mapped'
7760 option in a GDB `file' or `symbol-file' command has the same effect as
7761 starting GDB with the '-mapped' command-line option.
7763 You can cause GDB to read the entire symbol table immediately by using
7764 the '-readnow' option with any of the commands that load symbol table
7765 information (or on the GDB command line). This makes the command
7766 slower, but makes future operations faster.
7768 The -mapped and -readnow options are typically combined in order to
7769 build a `fred.syms' file that contains complete symbol information.
7770 A simple GDB invocation to do nothing but build a `.syms' file for future
7773 gdb -batch -nx -mapped -readnow programname
7775 The `.syms' file is specific to the host machine on which GDB is run.
7776 It holds an exact image of GDB's internal symbol table. It cannot be
7777 shared across multiple host platforms.
7779 * longjmp() handling
7781 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7782 siglongjmp() without losing control. This feature has not yet been ported to
7783 all systems. It currently works on many 386 platforms, all MIPS-based
7784 platforms (SGI, DECstation, etc), and Sun3/4.
7788 Preliminary work has been put in to support the new Solaris OS from Sun. At
7789 this time, it can control and debug processes, but it is not capable of
7794 As always, many many bug fixes. The major areas were with g++, and mipsread.
7795 People using the MIPS-based platforms should experience fewer mysterious
7796 crashes and trashed symbol tables.
7798 *** Changes in GDB-4.4:
7800 * New machines supported (host and target)
7802 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7804 BSD Reno on Vax vax-dec-bsd
7805 Ultrix on Vax vax-dec-ultrix
7807 * New machines supported (target)
7809 AMD 29000 embedded, using EBMON a29k-none-none
7813 GDB continues to improve its handling of C++. `References' work better.
7814 The demangler has also been improved, and now deals with symbols mangled as
7815 per the Annotated C++ Reference Guide.
7817 GDB also now handles `stabs' symbol information embedded in MIPS
7818 `ecoff' symbol tables. Since the ecoff format was not easily
7819 extensible to handle new languages such as C++, this appeared to be a
7820 good way to put C++ debugging info into MIPS binaries. This option
7821 will be supported in the GNU C compiler, version 2, when it is
7824 * New features for SVR4
7826 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7827 shared libraries. Debugging dynamically linked programs should present
7828 only minor differences from debugging statically linked programs.
7830 The `info proc' command will print out information about any process
7831 on an SVR4 system (including the one you are debugging). At the moment,
7832 it prints the address mappings of the process.
7834 If you bring up GDB on another SVR4 system, please send mail to
7835 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7837 * Better dynamic linking support in SunOS
7839 Reading symbols from shared libraries which contain debugging symbols
7840 now works properly. However, there remain issues such as automatic
7841 skipping of `transfer vector' code during function calls, which
7842 make it harder to debug code in a shared library, than to debug the
7843 same code linked statically.
7847 GDB is now using the latest `getopt' routines from the FSF. This
7848 version accepts the -- prefix for options with long names. GDB will
7849 continue to accept the old forms (-option and +option) as well.
7850 Various single letter abbreviations for options have been explicity
7851 added to the option table so that they won't get overshadowed in the
7852 future by other options that begin with the same letter.
7856 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7857 Many assorted bugs have been handled. Many more remain to be handled.
7858 See the various ChangeLog files (primarily in gdb and bfd) for details.
7861 *** Changes in GDB-4.3:
7863 * New machines supported (host and target)
7865 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7866 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7867 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7869 * Almost SCO Unix support
7871 We had hoped to support:
7872 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7873 (except for core file support), but we discovered very late in the release
7874 that it has problems with process groups that render gdb unusable. Sorry
7875 about that. I encourage people to fix it and post the fixes.
7877 * Preliminary ELF and DWARF support
7879 GDB can read ELF object files on System V Release 4, and can handle
7880 debugging records for C, in DWARF format, in ELF files. This support
7881 is preliminary. If you bring up GDB on another SVR4 system, please
7882 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7887 GDB now uses the latest `readline' library. One user-visible change
7888 is that two tabs will list possible command completions, which previously
7889 required typing M-? (meta-question mark, or ESC ?).
7893 The `stepi' bug that many of you noticed has been squashed.
7894 Many bugs in C++ have been handled. Many more remain to be handled.
7895 See the various ChangeLog files (primarily in gdb and bfd) for details.
7897 * State of the MIPS world (in case you wondered):
7899 GDB can understand the symbol tables emitted by the compilers
7900 supplied by most vendors of MIPS-based machines, including DEC. These
7901 symbol tables are in a format that essentially nobody else uses.
7903 Some versions of gcc come with an assembler post-processor called
7904 mips-tfile. This program is required if you want to do source-level
7905 debugging of gcc-compiled programs. I believe FSF does not ship
7906 mips-tfile with gcc version 1, but it will eventually come with gcc
7909 Debugging of g++ output remains a problem. g++ version 1.xx does not
7910 really support it at all. (If you're lucky, you should be able to get
7911 line numbers and stack traces to work, but no parameters or local
7912 variables.) With some work it should be possible to improve the
7915 When gcc version 2 is released, you will have somewhat better luck.
7916 However, even then you will get confusing results for inheritance and
7919 We will eventually provide full debugging of g++ output on
7920 DECstations. This will probably involve some kind of stabs-in-ecoff
7921 encapulation, but the details have not been worked out yet.
7924 *** Changes in GDB-4.2:
7926 * Improved configuration
7928 Only one copy of `configure' exists now, and it is not self-modifying.
7929 Porting BFD is simpler.
7933 The `step' and `next' commands now only stop at the first instruction
7934 of a source line. This prevents the multiple stops that used to occur
7935 in switch statements, for-loops, etc. `Step' continues to stop if a
7936 function that has debugging information is called within the line.
7940 Lots of small bugs fixed. More remain.
7942 * New host supported (not target)
7944 Intel 386 PC clone running Mach i386-none-mach
7947 *** Changes in GDB-4.1:
7949 * Multiple source language support
7951 GDB now has internal scaffolding to handle several source languages.
7952 It determines the type of each source file from its filename extension,
7953 and will switch expression parsing and number formatting to match the
7954 language of the function in the currently selected stack frame.
7955 You can also specifically set the language to be used, with
7956 `set language c' or `set language modula-2'.
7960 GDB now has preliminary support for the GNU Modula-2 compiler,
7961 currently under development at the State University of New York at
7962 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7963 continue through the fall of 1991 and into 1992.
7965 Other Modula-2 compilers are currently not supported, and attempting to
7966 debug programs compiled with them will likely result in an error as the
7967 symbol table is read. Feel free to work on it, though!
7969 There are hooks in GDB for strict type checking and range checking,
7970 in the `Modula-2 philosophy', but they do not currently work.
7974 GDB can now write to executable and core files (e.g. patch
7975 a variable's value). You must turn this switch on, specify
7976 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7977 by assigning a new value to a variable. Modifications take
7980 * Automatic SunOS shared library reading
7982 When you run your program, GDB automatically determines where its
7983 shared libraries (if any) have been loaded, and reads their symbols.
7984 The `share' command is no longer needed. This also works when
7985 examining core files.
7989 You can specify the number of lines that the `list' command shows.
7992 * New machines supported (host and target)
7994 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7995 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7996 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7998 * New hosts supported (not targets)
8000 IBM RT/PC: romp-ibm-aix or rtpc
8002 * New targets supported (not hosts)
8004 AMD 29000 embedded with COFF a29k-none-coff
8005 AMD 29000 embedded with a.out a29k-none-aout
8006 Ultracomputer remote kernel debug a29k-nyu-kern
8008 * New remote interfaces
8014 *** Changes in GDB-4.0:
8018 Wide output is wrapped at good places to make the output more readable.
8020 Gdb now supports cross-debugging from a host machine of one type to a
8021 target machine of another type. Communication with the target system
8022 is over serial lines. The ``target'' command handles connecting to the
8023 remote system; the ``load'' command will download a program into the
8024 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8025 also supports debugging of realtime processes running under VxWorks,
8026 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8027 stub on the target system.
8029 New CPUs supported include the AMD 29000 and Intel 960.
8031 GDB now reads object files and symbol tables via a ``binary file''
8032 library, which allows a single copy of GDB to debug programs of multiple
8033 object file types such as a.out and coff.
8035 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8036 refcard.dvi and refcard.ps are available to format it).
8039 * Control-Variable user interface simplified
8041 All variables that control the operation of the debugger can be set
8042 by the ``set'' command, and displayed by the ``show'' command.
8044 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8045 ``Show prompt'' produces the response:
8046 Gdb's prompt is new-gdb=>.
8048 What follows are the NEW set commands. The command ``help set'' will
8049 print a complete list of old and new set commands. ``help set FOO''
8050 will give a longer description of the variable FOO. ``show'' will show
8051 all of the variable descriptions and their current settings.
8053 confirm on/off: Enables warning questions for operations that are
8054 hard to recover from, e.g. rerunning the program while
8055 it is already running. Default is ON.
8057 editing on/off: Enables EMACS style command line editing
8058 of input. Previous lines can be recalled with
8059 control-P, the current line can be edited with control-B,
8060 you can search for commands with control-R, etc.
8063 history filename NAME: NAME is where the gdb command history
8064 will be stored. The default is .gdb_history,
8065 or the value of the environment variable
8068 history size N: The size, in commands, of the command history. The
8069 default is 256, or the value of the environment variable
8072 history save on/off: If this value is set to ON, the history file will
8073 be saved after exiting gdb. If set to OFF, the
8074 file will not be saved. The default is OFF.
8076 history expansion on/off: If this value is set to ON, then csh-like
8077 history expansion will be performed on
8078 command line input. The default is OFF.
8080 radix N: Sets the default radix for input and output. It can be set
8081 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8082 in the current radix, so "set radix 10" is always a no-op.
8084 height N: This integer value is the number of lines on a page. Default
8085 is 24, the current `stty rows'' setting, or the ``li#''
8086 setting from the termcap entry matching the environment
8089 width N: This integer value is the number of characters on a line.
8090 Default is 80, the current `stty cols'' setting, or the ``co#''
8091 setting from the termcap entry matching the environment
8094 Note: ``set screensize'' is obsolete. Use ``set height'' and
8095 ``set width'' instead.
8097 print address on/off: Print memory addresses in various command displays,
8098 such as stack traces and structure values. Gdb looks
8099 more ``symbolic'' if you turn this off; it looks more
8100 ``machine level'' with it on. Default is ON.
8102 print array on/off: Prettyprint arrays. New convenient format! Default
8105 print demangle on/off: Print C++ symbols in "source" form if on,
8108 print asm-demangle on/off: Same, for assembler level printouts
8111 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8114 * Support for Epoch Environment.
8116 The epoch environment is a version of Emacs v18 with windowing. One
8117 new command, ``inspect'', is identical to ``print'', except that if you
8118 are running in the epoch environment, the value is printed in its own
8122 * Support for Shared Libraries
8124 GDB can now debug programs and core files that use SunOS shared libraries.
8125 Symbols from a shared library cannot be referenced
8126 before the shared library has been linked with the program (this
8127 happens after you type ``run'' and before the function main() is entered).
8128 At any time after this linking (including when examining core files
8129 from dynamically linked programs), gdb reads the symbols from each
8130 shared library when you type the ``sharedlibrary'' command.
8131 It can be abbreviated ``share''.
8133 sharedlibrary REGEXP: Load shared object library symbols for files
8134 matching a unix regular expression. No argument
8135 indicates to load symbols for all shared libraries.
8137 info sharedlibrary: Status of loaded shared libraries.
8142 A watchpoint stops execution of a program whenever the value of an
8143 expression changes. Checking for this slows down execution
8144 tremendously whenever you are in the scope of the expression, but is
8145 quite useful for catching tough ``bit-spreader'' or pointer misuse
8146 problems. Some machines such as the 386 have hardware for doing this
8147 more quickly, and future versions of gdb will use this hardware.
8149 watch EXP: Set a watchpoint (breakpoint) for an expression.
8151 info watchpoints: Information about your watchpoints.
8153 delete N: Deletes watchpoint number N (same as breakpoints).
8154 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8155 enable N: Re-enables watchpoint number N (same as breakpoints).
8158 * C++ multiple inheritance
8160 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8163 * C++ exception handling
8165 Gdb now supports limited C++ exception handling. Besides the existing
8166 ability to breakpoint on an exception handler, gdb can breakpoint on
8167 the raising of an exception (before the stack is peeled back to the
8170 catch FOO: If there is a FOO exception handler in the dynamic scope,
8171 set a breakpoint to catch exceptions which may be raised there.
8172 Multiple exceptions (``catch foo bar baz'') may be caught.
8174 info catch: Lists all exceptions which may be caught in the
8175 current stack frame.
8178 * Minor command changes
8180 The command ``call func (arg, arg, ...)'' now acts like the print
8181 command, except it does not print or save a value if the function's result
8182 is void. This is similar to dbx usage.
8184 The ``up'' and ``down'' commands now always print the frame they end up
8185 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8186 frames without printing.
8188 * New directory command
8190 'dir' now adds directories to the FRONT of the source search path.
8191 The path starts off empty. Source files that contain debug information
8192 about the directory in which they were compiled can be found even
8193 with an empty path; Sun CC and GCC include this information. If GDB can't
8194 find your source file in the current directory, type "dir .".
8196 * Configuring GDB for compilation
8198 For normal use, type ``./configure host''. See README or gdb.texinfo
8201 GDB now handles cross debugging. If you are remotely debugging between
8202 two different machines, type ``./configure host -target=targ''.
8203 Host is the machine where GDB will run; targ is the machine
8204 where the program that you are debugging will run.