1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 11
8 maint set backtrace-on-fatal-signal on|off
9 maint show backtrace-on-fatal-signal
10 This setting is 'on' by default. When 'on' GDB will print a limited
11 backtrace to stderr in the situation where GDB terminates with a
12 fatal signal. This only supported on some platforms where the
13 backtrace and backtrace_symbols_fd functions are available.
15 set source open on|off
17 This setting, which is on by default, controls whether GDB will try
18 to open source code files. Switching this off will stop GDB trying
19 to open and read source code files, which can be useful if the files
20 are located over a slow network connection.
24 These are now deprecated aliases for "set max-value-size" and
25 "show max-value-size".
27 maint set internal-error backtrace on|off
28 maint show internal-error backtrace
29 maint set internal-warning backtrace on|off
30 maint show internal-warning backtrace
31 GDB can now print a backtrace of itself when it encounters either an
32 internal-error, or an internal-warning. This is on by default for
33 internal-error and off by default for internal-warning.
37 ** New function gdb.add_history(), which takes a gdb.Value object
38 and adds the value it represents to GDB's history list. An
39 integer, the index of the new item in the history list, is
42 ** New gdb.events.gdb_exiting event. This event is called with a
43 gdb.GdbExitingEvent object which has the read-only attribute
44 'exit_code', which contains the value of the GDB exit code. This
45 event is triggered once GDB decides it is going to exit, but
46 before GDB starts to clean up its internal state.
48 ** New function gdb.architecture_names(), which returns a list
49 containing all of the possible Architecture.name() values. Each
52 ** New function gdb.Architecture.integer_type(), which returns an
53 integer type given a size and a signed-ness.
55 * New features in the GDB remote stub, GDBserver
57 ** GDBserver is now supported on OpenRISC GNU/Linux.
59 * New native configurations
61 GNU/Linux/OpenRISC or1k*-*-linux*
65 * The 'set disassembler-options' command now supports specifying options
68 * GDB now supports general memory tagging functionality if the underlying
69 architecture supports the proper primitives and hooks. Currently this is
70 enabled only for AArch64 MTE.
74 - Additional information when the inferior crashes with a SIGSEGV caused by
75 a memory tag violation.
77 - A new modifier 'm' for the "x" command, which displays allocation tags for a
78 particular memory range.
80 - Display of memory tag mismatches by "print", for addresses and
81 pointers, if memory tagging is supported by the architecture.
83 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
88 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
90 The MI -break-insert and -dprintf-insert commands now support a
91 new "--qualified" option that makes GDB interpret a specified
92 function name as a complete fully-qualified name. This is the
93 equivalent of the CLI's "break -qualified" and "dprintf
96 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
98 The MI -break-insert and -dprintf-insert commands now support a
99 '--force-condition' flag to forcibly define a condition even when
100 the condition is invalid at all locations of the breakpoint. This
101 is equivalent to the '-force-condition' flag of the CLI's "break"
104 ** '-break-condition --force'
106 The MI -break-condition command now supports a '--force' flag to
107 forcibly define a condition even when the condition is invalid at
108 all locations of the selected breakpoint. This is equivalent to
109 the '-force' flag of the CLI's "cond" command.
111 ** '-file-list-exec-source-files [--group-by-objfile]
112 [--basename | --dirname]
115 The existing -file-list-exec-source-files command now takes an
116 optional REGEXP which is used to filter the source files that are
117 included in the results.
119 By default REGEXP is matched against the full filename of the
120 source file. When one of --basename or --dirname is given then
121 REGEXP is only matched against the specified part of the full
124 When the optional --group-by-objfile flag is used the output
125 format is changed, the results are now a list of object files
126 (executable and libraries) with the source files that are
127 associated with each object file.
129 The results from -file-list-exec-source-files now include a
130 'debug-fully-read' field which takes the value 'true' or 'false'.
131 A 'true' value indicates the source file is from a compilation
132 unit that has had its debug information fully read in by GDB, a
133 value of 'false' indicates GDB has only performed a partial scan
134 of the debug information so far.
136 * GDB now supports core file debugging for x86_64 Cygwin programs.
138 * GDB will now look for the .gdbinit file in a config directory before
139 looking for ~/.gdbinit. The file is searched for in the following
140 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
141 $HOME/.gdbinit. On Apple hosts the search order is instead:
142 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
144 * GDB now supports fixed point types which are described in DWARF
145 as base types with a fixed-point encoding. Additionally, support
146 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
149 For Ada, this allows support for fixed point types without requiring
150 the use of the GNAT encoding (based on information added to the type's
151 name following a GNAT-specific format).
153 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
154 or ~/.gdbearlyinit if these files are present. These files are
155 processed earlier than any of the other initialization files and
156 can affect parts of GDB's startup that previously had already been
157 completed before the initialization files were read, for example
158 styling of the initial GDB greeting.
160 * GDB now has two new options "--early-init-command" and
161 "--early-init-eval-command" with corresponding short options "-eix"
162 and "-eiex" that allow options (that would normally appear in a
163 gdbearlyinit file) to be passed on the command line.
165 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
166 now understood by GDB, and can be used to describe the vector
167 registers of a target. The precise requirements of this register
168 feature are documented in the GDB manual.
170 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
171 supported by GDB and describes a new VPR register from the ARM MVE
172 (Helium) extension. See the GDB manual for more information.
176 ** TUI windows now support mouse actions. The mouse wheel scrolls
177 the appropriate window.
179 ** Key combinations that do not have a specific action on the
180 focused window are passed to GDB. For example, you now can use
181 Ctrl-Left/Ctrl-Right to move between words in the command window
182 regardless of which window is in focus. Previously you would
183 need to focus on the command window for such key combinations to
189 show debug event-loop
190 Control the display of debug output about GDB's event loop.
192 set print memory-tag-violations
193 show print memory-tag-violations
194 Control whether to display additional information about memory tag violations
195 when printing pointers and addresses. Architecture support for memory
196 tagging is required for this option to have an effect.
198 maintenance flush symbol-cache
199 maintenance flush register-cache
200 These new commands are equivalent to the already existing commands
201 'maintenance flush-symbol-cache' and 'flushregs' respectively.
203 maintenance flush dcache
204 A new command to flush the dcache.
206 maintenance info target-sections
207 Print GDB's internal target sections table.
210 Print the JIT code objects in the inferior known to GDB.
212 memory-tag show-logical-tag POINTER
213 Print the logical tag for POINTER.
214 memory-tag with-logical-tag POINTER TAG
215 Print POINTER with logical tag TAG.
216 memory-tag show-allocation-tag ADDRESS
217 Print the allocation tag for ADDRESS.
218 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
219 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
220 memory-tag check POINTER
221 Validate that POINTER's logical tag matches the allocation tag.
223 set startup-quietly on|off
225 When 'on', this causes GDB to act as if "-silent" were passed on the
226 command line. This command needs to be added to an early
227 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
230 set print type hex on|off
232 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
233 and offsets of struct members. When 'off', decimal notation is used.
235 set python ignore-environment on|off
236 show python ignore-environment
237 When 'on', this causes GDB's builtin Python to ignore any
238 environment variables that would otherwise affect how Python
239 behaves. This command needs to be added to an early initialization
240 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
242 set python dont-write-bytecode auto|on|off
243 show python dont-write-bytecode
244 When 'on', this causes GDB's builtin Python to not write any
245 byte-code (.pyc files) to disk. This command needs to be added to
246 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
247 order to affect GDB. When 'off' byte-code will always be written.
248 When set to 'auto' (the default) Python will check the
249 PYTHONDONTWRITEBYTECODE environment variable.
253 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
254 [-force-condition] [if CONDITION]
255 This command would previously refuse setting a breakpoint if the
256 CONDITION expression is invalid at a location. It now accepts and
257 defines the breakpoint if there is at least one location at which
258 the CONDITION is valid. The locations for which the CONDITION is
259 invalid, are automatically disabled. If CONDITION is invalid at all
260 of the locations, setting the breakpoint is still rejected. However,
261 the '-force-condition' flag can be used in this case for forcing GDB to
262 define the breakpoint, making all the current locations automatically
263 disabled. This may be useful if the user knows the condition will
264 become meaningful at a future location, e.g. due to a shared library
267 condition [-force] N COND
268 The behavior of this command is changed the same way for the 'break'
269 command as explained above. The '-force' flag can be used to force
270 GDB into defining the condition even when COND is invalid for all the
271 current locations of breakpoint N.
274 maintenance flush-symbol-cache
275 These commands are deprecated in favor of the new commands
276 'maintenance flush register-cache' and 'maintenance flush
277 symbol-cache' respectively.
279 set style version foreground COLOR
280 set style version background COLOR
281 set style version intensity VALUE
282 Control the styling of GDB's version number text.
285 When the ID parameter is omitted, then this command prints information
286 about the current inferior. When the ID parameter is present, the
287 behavior of the command is unchanged and have the inferior ID become
288 the current inferior.
290 maintenance info sections
291 The ALLOBJ keyword has been replaced with an -all-objects command
292 line flag. It is now possible to filter which sections are printed
293 even when -all-objects is passed.
295 ptype[/FLAGS] TYPE | EXPRESSION
296 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
297 notation is used when printing sizes and offsets of struct members.
298 When '/d' is set, decimal notation is used when printing sizes and
299 offsets of struct members. Default behavior is given by 'show print
303 The info sources command output has been restructured. The results
304 are now based around a list of objfiles (executable and libraries),
305 and for each objfile the source files that are part of that objfile
308 * Removed targets and native configurations
310 ARM Symbian arm*-*-symbianelf*
315 Request the remote to send allocation tags for a particular memory range.
317 Request the remote to store the specified allocation tags to the requested
322 ** Improved support for rvalue reference values:
323 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
324 value-referenced-value procedure now handles rvalue reference
327 ** New procedures for obtaining value variants:
328 value-reference-value, value-rvalue-reference-value and
331 ** Temporary breakpoints can now be created with make-breakpoint and
332 tested for using breakpoint-temporary?.
336 ** Inferior objects now contain a read-only 'connection_num' attribute that
337 gives the connection number as seen in 'info connections' and
340 ** New method gdb.Frame.level() which returns the stack level of the
343 ** New method gdb.PendingFrame.level() which returns the stack level
346 ** When hitting a catchpoint, the Python API will now emit a
347 gdb.BreakpointEvent rather than a gdb.StopEvent. The
348 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
350 ** Python TUI windows can now receive mouse click events. If the
351 Window object implements the click method, it is called for each
352 mouse click event in this window.
354 *** Changes in GDB 10
356 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
357 and "org.gnu.gdb.arc.aux". The old names are still supported but
358 must be considered obsolete. They will be deprecated after some
361 * Help and apropos commands will now show the documentation of a
362 command only once, even if that command has one or more aliases.
363 These commands now show the command name, then all of its aliases,
364 and finally the description of the command.
366 * 'help aliases' now shows only the user defined aliases. GDB predefined
367 aliases are shown together with their aliased command.
369 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
370 debugging information as well as source code.
372 When built with debuginfod, GDB can automatically query debuginfod
373 servers for the separate debug files and source code of the executable
376 To build GDB with debuginfod, pass --with-debuginfod to configure (this
377 requires libdebuginfod, the debuginfod client library).
379 debuginfod is distributed with elfutils, starting with version 0.178.
381 You can get the latest version from https://sourceware.org/elfutils.
383 * Multi-target debugging support
385 GDB now supports debugging multiple target connections
386 simultaneously. For example, you can now have each inferior
387 connected to different remote servers running in different machines,
388 or have one inferior debugging a local native process, an inferior
389 debugging a core dump, etc.
391 This support is experimental and comes with some limitations -- you
392 can only resume multiple targets simultaneously if all targets
393 support non-stop mode, and all remote stubs or servers must support
394 the same set of remote protocol features exactly. See also "info
395 connections" and "add-inferior -no-connection" below, and "maint set
396 target-non-stop" in the user manual.
398 * New features in the GDB remote stub, GDBserver
400 ** GDBserver is now supported on ARC GNU/Linux.
402 ** GDBserver is now supported on RISC-V GNU/Linux.
404 ** GDBserver no longer supports these host triplets:
415 i[34567]86-*-mingw32ce*
417 * Debugging MS-Windows processes now sets $_exitsignal when the
418 inferior is terminated by a signal, instead of setting $_exitcode.
420 * Multithreaded symbol loading has now been enabled by default on systems
421 that support it (see entry for GDB 9, below), providing faster
422 performance for programs with many symbols.
424 * The $_siginfo convenience variable now also works on Windows targets,
425 and will display the EXCEPTION_RECORD of the last handled exception.
427 * TUI windows can now be arranged horizontally.
429 * The command history filename can now be set to the empty string
430 either using 'set history filename' or by setting 'GDBHISTFILE=' in
431 the environment. The effect of setting this filename to the empty
432 string is that GDB will not try to load any previous command
435 * On Windows targets, it is now possible to debug 32-bit programs with a
440 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
441 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
442 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
443 running process, this new option indicates whether to detect
444 a mismatch between the current executable file loaded by GDB and the
445 executable file used to start the process. If 'ask', the default,
446 display a warning and ask the user whether to load the process
447 executable file; if 'warn', just display a warning; if 'off', don't
448 attempt to detect a mismatch.
450 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
451 Define a new TUI layout, specifying its name and the windows that
454 maintenance print xml-tdesc [FILE]
455 Prints the current target description as an XML document. If the
456 optional FILE is provided (which is an XML target description) then
457 the target description is read from FILE into GDB, and then
460 maintenance print core-file-backed-mappings
461 Prints file-backed mappings loaded from a core file's note section.
462 Output is expected to be similar to that of "info proc mappings".
464 set debug fortran-array-slicing on|off
465 show debug fortran-array-slicing
466 Print debugging when taking slices of Fortran arrays.
468 set fortran repack-array-slices on|off
469 show fortran repack-array-slices
470 When taking slices from Fortran arrays and strings, if the slice is
471 non-contiguous within the original value then, when this option is
472 on, the new value will be repacked into a single contiguous value.
473 When this option is off, then the value returned will consist of a
474 descriptor that describes the slice within the memory of the
475 original parent value.
479 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
480 The alias command can now specify default args for an alias.
481 GDB automatically prepends the alias default args to the argument list
482 provided explicitly by the user.
483 For example, to have a backtrace with full details, you can define
485 'alias bt_ALL = backtrace -entry-values both -frame-arg all
486 -past-main -past-entry -full'.
487 Alias default arguments can also use a set of nested 'with' commands,
488 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
489 defines the alias pp10 that will pretty print a maximum of 10 elements
490 of the given expression (if the expression is an array).
494 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
500 ** gdb.register_window_type can be used to implement new TUI windows
503 ** Dynamic types can now be queried. gdb.Type has a new attribute,
504 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
505 field of a dynamic type may have None for its "bitpos" attribute
508 ** Commands written in Python can be in the "TUI" help class by
509 registering with the new constant gdb.COMMAND_TUI.
511 ** New method gdb.PendingFrame.architecture () to retrieve the
512 architecture of the pending frame.
514 ** New gdb.Architecture.registers method that returns a
515 gdb.RegisterDescriptorIterator object, an iterator that returns
516 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
517 way to query the registers available for an architecture.
519 ** New gdb.Architecture.register_groups method that returns a
520 gdb.RegisterGroupIterator object, an iterator that returns
521 gdb.RegisterGroup objects. The new RegisterGroup is a way to
522 discover the available register groups.
526 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
528 ** Procedures 'memory-port-read-buffer-size',
529 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
530 and 'set-memory-port-write-buffer-size!' are deprecated. When
531 using Guile 2.2 and later, users who need to control the size of
532 a memory port's internal buffer can use the 'setvbuf' procedure.
536 * 'thread-exited' event is now available in the annotations interface.
538 * New built-in convenience variables $_gdb_major and $_gdb_minor
539 provide the GDB version. They are handy for conditionally using
540 features available only in or since specific GDB versions, in
541 scripts that should work error-free with many different versions,
542 such as in system-wide init files.
544 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
545 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
546 of the GDB settings and the GDB maintenance settings. They are handy
547 for changing the logic of user defined commands depending on the
548 current GDB settings.
550 * GDB now supports Thread Local Storage (TLS) variables on several
551 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
552 architectures require kernel changes. TLS is not yet supported for
553 amd64 and i386 process core dumps.
555 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
556 addresses that required unmasking are shown in the backtrace with the
559 * Two new convenience functions $_cimag and $_creal that extract the
560 imaginary and real parts respectively from complex numbers.
562 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
563 provide the exitcode or exit status of the shell commands launched by
564 GDB commands such as "shell", "pipe" and "make".
566 * The command define-prefix can now define user defined prefix commands.
567 User defined commands can now be defined using these user defined prefix
570 * Command names can now use the . character.
572 * The RX port now supports XML target descriptions.
574 * GDB now shows the Ada task names at more places, e.g. in task switching
577 * GDB can now be compiled with Python 3 on Windows.
579 * New convenience variable $_ada_exception holds the address of the
580 Ada exception being thrown. This is set by Ada-related catchpoints.
582 * GDB can now place breakpoints on nested functions and subroutines in
583 Fortran code. The '::' operator can be used between parent and
584 child scopes when placing breakpoints, for example:
586 (gdb) break outer_function::inner_function
588 The 'outer_function::' prefix is only needed if 'inner_function' is
589 not visible in the current scope.
591 * In addition to the system-wide gdbinit file, if configured with
592 --with-system-gdbinit-dir, GDB will now also load files in that directory
593 as system gdbinit files, unless the -nx or -n flag is provided. Files
594 with extensions .gdb, .py and .scm are supported as long as GDB was
595 compiled with support for that language.
597 * GDB now supports multithreaded symbol loading for higher performance.
598 This feature is still in testing, so it is disabled by default. You
599 can turn it on using 'maint set worker-threads unlimited'.
603 ** The gdb.Value type has a new method 'format_string' which returns a
604 string representing the value. The formatting is controlled by the
605 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
606 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
607 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
609 ** gdb.Type has a new property 'objfile' which returns the objfile the
612 ** The frame information printed by the python frame filtering code
613 is now consistent with what the 'backtrace' command prints when
614 there are no filters, or when the 'backtrace' '-no-filters' option
617 ** The new function gdb.lookup_static_symbol can be used to look up
618 symbols with static linkage.
620 ** The new function gdb.lookup_static_symbols can be used to look up
621 all static symbols with static linkage.
623 ** gdb.Objfile has new methods 'lookup_global_symbol' and
624 'lookup_static_symbol' to lookup a symbol from this objfile only.
626 ** gdb.Block now supports the dictionary syntax for accessing symbols in
627 this block (e.g. block['local_variable']).
631 | [COMMAND] | SHELL_COMMAND
632 | -d DELIM COMMAND DELIM SHELL_COMMAND
633 pipe [COMMAND] | SHELL_COMMAND
634 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
635 Executes COMMAND and sends its output to SHELL_COMMAND.
636 With no COMMAND, repeat the last executed command
637 and send its output to SHELL_COMMAND.
639 define-prefix COMMAND
640 Define or mark a command as a user-defined prefix command.
642 with SETTING [VALUE] [-- COMMAND]
643 w SETTING [VALUE] [-- COMMAND]
644 Temporarily set SETTING, run COMMAND, and restore SETTING.
645 Usage: with SETTING -- COMMAND
646 With no COMMAND, repeats the last executed command.
647 SETTING is any GDB setting you can change with the "set"
648 subcommands. For example, 'with language c -- print someobj'
649 temporarily switches to the C language in order to print someobj.
650 Settings can be combined: 'w lang c -- w print elements unlimited --
651 usercmd' switches to the C language and runs usercmd with no limit
652 of array elements to print.
654 maint with SETTING [VALUE] [-- COMMAND]
655 Like "with", but works with "maintenance set" settings.
657 set may-call-functions [on|off]
658 show may-call-functions
659 This controls whether GDB will attempt to call functions in
660 the program, such as with expressions in the print command. It
661 defaults to on. Calling functions in the program being debugged
662 can have undesired side effects. It is now possible to forbid
663 such function calls. If function calls are forbidden, GDB will throw
664 an error when a command (such as print expression) calls a function
667 set print finish [on|off]
669 This controls whether the `finish' command will display the value
670 that is returned by the current function. When `off', the value is
671 still entered into the value history, but it is not printed. The
676 Allows deeply nested structures to be simplified when printing by
677 replacing deeply nested parts (beyond the max-depth) with ellipses.
678 The default max-depth is 20, but this can be set to unlimited to get
679 the old behavior back.
681 set print raw-values [on|off]
682 show print raw-values
683 By default, GDB applies the enabled pretty printers when printing a
684 value. This allows to ignore the enabled pretty printers for a series
685 of commands. The default is 'off'.
687 set logging debugredirect [on|off]
688 By default, GDB debug output will go to both the terminal and the logfile.
689 Set if you want debug output to go only to the log file.
691 set style title foreground COLOR
692 set style title background COLOR
693 set style title intensity VALUE
694 Control the styling of titles.
696 set style highlight foreground COLOR
697 set style highlight background COLOR
698 set style highlight intensity VALUE
699 Control the styling of highlightings.
701 maint set worker-threads
702 maint show worker-threads
703 Control the number of worker threads that can be used by GDB. The
704 default is 0. "unlimited" lets GDB choose a number that is
705 reasonable. Currently worker threads are only used when demangling
706 the names of linker symbols.
708 set style tui-border foreground COLOR
709 set style tui-border background COLOR
710 Control the styling of TUI borders.
712 set style tui-active-border foreground COLOR
713 set style tui-active-border background COLOR
714 Control the styling of the active TUI border.
716 maint set test-settings KIND
717 maint show test-settings KIND
718 A set of commands used by the testsuite for exercising the settings
721 maint set tui-resize-message [on|off]
722 maint show tui-resize-message
723 Control whether GDB prints a message each time the terminal is
724 resized when in TUI mode. This is primarily useful for testing the
727 set print frame-info [short-location|location|location-and-address
728 |source-and-location|source-line|auto]
729 show print frame-info
730 This controls what frame information is printed by the commands printing
731 a frame. This setting will e.g. influence the behaviour of 'backtrace',
732 'frame', 'stepi'. The python frame filtering also respect this setting.
733 The 'backtrace' '-frame-info' option can override this global setting.
735 set tui compact-source
736 show tui compact-source
738 Enable the "compact" display mode for the TUI source window. The
739 compact display uses only as much space as is needed for the line
740 numbers in the current file, and only a single space to separate the
741 line numbers from the source.
743 info modules [-q] [REGEXP]
744 Return a list of Fortran modules matching REGEXP, or all modules if
747 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
748 Return a list of functions within all modules, grouped by module.
749 The list of functions can be restricted with the optional regular
750 expressions. MODULE_REGEXP matches against the module name,
751 TYPE_REGEXP matches against the function type signature, and REGEXP
752 matches against the function name.
754 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
755 Return a list of variables within all modules, grouped by module.
756 The list of variables can be restricted with the optional regular
757 expressions. MODULE_REGEXP matches against the module name,
758 TYPE_REGEXP matches against the variable type, and REGEXP matches
759 against the variable name.
761 set debug remote-packet-max-chars
762 show debug remote-packet-max-chars
763 Controls the number of characters to output in a remote packet when using
765 The default is 512 bytes.
768 Lists the target connections currently in use.
773 The "help" command uses the title style to enhance the
774 readibility of its output by styling the classes and
778 Similarly to "help", the "apropos" command also uses the
779 title style for the command names. "apropos" accepts now
780 a flag "-v" (verbose) to show the full documentation
781 of matching commands and to use the highlight style to mark
782 the documentation parts matching REGEXP.
786 The GDB printf and eval commands can now print C-style and Ada-style
787 string convenience variables without calling functions in the program.
788 This allows to do formatted printing of strings without having
789 a running inferior, or when debugging a core dump.
791 info sources [-dirname | -basename] [--] [REGEXP]
792 This command has now optional arguments to only print the files
793 whose names match REGEXP. The arguments -dirname and -basename
794 allow to restrict matching respectively to the dirname and basename
798 The "show style" and its subcommands are now styling
799 a style name in their output using its own style, to help
800 the user visualize the different styles.
802 set print frame-arguments
803 The new value 'presence' indicates to only indicate the presence of
804 arguments using ..., instead of printing argument names and values.
806 set print raw-frame-arguments
807 show print raw-frame-arguments
809 These commands replace the similarly-named "set/show print raw
810 frame-arguments" commands (now with a dash instead of a space). The
811 old commands are now deprecated and may be removed in a future
814 add-inferior [-no-connection]
815 The add-inferior command now supports a "-no-connection" flag that
816 makes the new inferior start with no target connection associated.
817 By default, the new inferior inherits the target connection of the
818 current inferior. See also "info connections".
821 This command's output now includes a new "Connection" column
822 indicating which target connection an inferior is bound to. See
823 "info connections" above.
825 maint test-options require-delimiter
826 maint test-options unknown-is-error
827 maint test-options unknown-is-operand
828 maint show test-options-completion-result
829 Commands used by the testsuite to validate the command options
832 focus, winheight, +, -, >, <
833 These commands are now case-sensitive.
835 * New command options, command completion
837 GDB now has a standard infrastructure to support dash-style command
838 options ('-OPT'). One benefit is that commands that use it can
839 easily support completion of command line arguments. Try "CMD
840 -[TAB]" or "help CMD" to find options supported by a command. Over
841 time, we intend to migrate most commands to this infrastructure. A
842 number of commands got support for new command options in this
845 ** The "print" and "compile print" commands now support a number of
846 options that allow overriding relevant global print settings as
847 set by "set print" subcommands:
851 -array-indexes [on|off]
852 -elements NUMBER|unlimited
857 -repeats NUMBER|unlimited
858 -static-members [on|off]
863 Note that because the "print"/"compile print" commands accept
864 arbitrary expressions which may look like options (including
865 abbreviations), if you specify any command option, then you must
866 use a double dash ("--") to mark the end of argument processing.
868 ** The "backtrace" command now supports a number of options that
869 allow overriding relevant global print settings as set by "set
870 backtrace" and "set print" subcommands:
872 -entry-values no|only|preferred|if-needed|both|compact|default
873 -frame-arguments all|scalars|none
874 -raw-frame-arguments [on|off]
875 -frame-info auto|source-line|location|source-and-location
876 |location-and-address|short-location
880 In addition, the full/no-filters/hide qualifiers are now also
881 exposed as command options too:
887 ** The "frame apply", "tfaas" and "faas" commands similarly now
888 support the following options:
893 ** The new "info sources" options -dirname and -basename options
894 are using the standard '-OPT' infrastructure.
896 All options above can also be abbreviated. The argument of boolean
897 (on/off) options can be 0/1 too, and also the argument is assumed
898 "on" if omitted. This allows writing compact command invocations,
901 (gdb) p -ra -p -o 0 -- *myptr
903 The above is equivalent to:
905 (gdb) print -raw-values -pretty -object off -- *myptr
907 ** The "info types" command now supports the '-q' flag to disable
908 printing of some header information in a similar fashion to "info
909 variables" and "info functions".
911 ** The "info variables", "info functions", and "whereis" commands
912 now take a '-n' flag that excludes non-debug symbols (symbols
913 from the symbol table, not from the debug info such as DWARF)
916 * Completion improvements
918 ** GDB can now complete the options of the "thread apply all" and
919 "taas" commands, and their "-ascending" option can now be
922 ** GDB can now complete the options of the "info threads", "info
923 functions", "info variables", "info locals", and "info args"
926 ** GDB can now complete the options of the "compile file" and
927 "compile code" commands. The "compile file" command now
928 completes on filenames.
930 ** GDB can now complete the backtrace command's
931 "full/no-filters/hide" qualifiers.
933 * In settings, you can now abbreviate "unlimited".
935 E.g., "set print elements u" is now equivalent to "set print
941 This lists all the possible completions for the rest of the line, if it
942 were to be given as a command itself. This is intended for use by MI
943 frontends in cases when separate CLI and MI channels cannot be used.
945 -catch-throw, -catch-rethrow, and -catch-catch
946 These can be used to catch C++ exceptions in a similar fashion to
947 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
949 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
950 These commands are the MI equivalent of the CLI commands 'info
951 functions', 'info types', and 'info variables' respectively.
953 -symbol-info-modules, this is the MI equivalent of the CLI 'info
956 -symbol-info-module-functions and -symbol-info-module-variables.
957 These commands are the MI equivalent of the CLI commands 'info
958 module functions' and 'info module variables'.
962 ** The default version of the MI interpreter is now 3 (-i=mi3).
964 ** The output of information about multi-location breakpoints (which is
965 syntactically incorrect in MI 2) has changed in MI 3. This affects
966 the following commands and events:
970 - =breakpoint-created
971 - =breakpoint-modified
973 The -fix-multi-location-breakpoint-output command can be used to enable
974 this behavior with previous MI versions.
976 ** Backtraces and frames include a new optional field addr_flags which is
977 given after the addr field. On AArch64 this contains PAC if the address
978 has been masked in the frame. On all other targets the field is not
983 The testsuite now creates the files gdb.cmd (containing the arguments
984 used to launch GDB) and gdb.in (containing all the commands sent to
985 GDB) in the output directory for each test script. Multiple invocations
986 are appended with .1, .2, .3 etc.
988 * Building GDB and GDBserver now requires GNU make >= 3.82.
990 Using another implementation of the make program or an earlier version of
991 GNU make to build GDB or GDBserver is not supported.
993 * Building GDB now requires GNU readline >= 7.0.
995 GDB now bundles GNU readline 8.0, but if you choose to use
996 --with-system-readline, only readline >= 7.0 can be used.
998 * The TUI SingleKey keymap is now named "SingleKey". This can be used
999 from .inputrc to bind keys in this keymap. This feature is only
1000 available when gdb is built against GNU readline 8.0 or later.
1002 * Removed targets and native configurations
1004 GDB no longer supports debugging the Cell Broadband Engine. This includes
1005 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1006 of Cell/B.E. applications that use both the PPU and SPU architectures.
1012 * Removed targets and native configurations
1014 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1015 sparc*-*-solaris2.10
1017 *** Changes in GDB 8.3
1019 * GDB and GDBserver now support access to additional registers on
1020 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1023 * GDB now has experimental support for the compilation and injection of
1024 C++ source code into the inferior. This beta release does not include
1025 support for several language features, such as templates, constructors,
1028 This feature requires GCC 7.1 or higher built with libcp1.so
1031 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1032 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1033 'ADDRESS:PORT' method.
1035 * DWARF index cache: GDB can now automatically save indices of DWARF
1036 symbols on disk to speed up further loading of the same binaries.
1038 * Ada task switching is now supported on aarch64-elf targets when
1039 debugging a program using the Ravenscar Profile. For more information,
1040 see the "Tasking Support when using the Ravenscar Profile" section
1041 in the GDB user manual.
1043 * GDB in batch mode now exits with status 1 if the last command to be
1046 * The RISC-V target now supports target descriptions.
1048 * System call catchpoints now support system call aliases on FreeBSD.
1049 When the ABI of a system call changes in FreeBSD, this is
1050 implemented by leaving a compatibility system call using the old ABI
1051 at the existing number and allocating a new system call number for
1052 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1053 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1054 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1055 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1056 so that a system call catchpoint for the 'kevent' system call will
1057 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1058 binaries. This ensures that 'kevent' system calls are caught for
1059 binaries using either the old or new ABIs.
1061 * Terminal styling is now available for the CLI and the TUI. GNU
1062 Source Highlight can additionally be used to provide styling of
1063 source code snippets. See the "set style" commands, below, for more
1066 * Removed support for old demangling styles arm, edg, gnu, hp and
1071 set debug compile-cplus-types
1072 show debug compile-cplus-types
1073 Control the display of debug output about type conversion in the
1074 C++ compile feature. Commands have no effect while compiling
1075 for other languages.
1079 Control whether debug output about files/functions skipping is
1082 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1083 Apply a command to some frames.
1084 FLAG arguments allow to control what output to produce and how to handle
1085 errors raised when applying COMMAND to a frame.
1088 Apply a command to all threads (ignoring errors and empty output).
1089 Shortcut for 'thread apply all -s COMMAND'.
1092 Apply a command to all frames (ignoring errors and empty output).
1093 Shortcut for 'frame apply all -s COMMAND'.
1096 Apply a command to all frames of all threads (ignoring errors and empty
1098 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1100 maint set dwarf unwinders (on|off)
1101 maint show dwarf unwinders
1102 Control whether DWARF unwinders can be used.
1105 Display a list of open files for a process.
1109 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1110 These commands all now take a frame specification which
1111 is either a frame level, or one of the keywords 'level', 'address',
1112 'function', or 'view' followed by a parameter. Selecting a frame by
1113 address, or viewing a frame outside the current backtrace now
1114 requires the use of a keyword. Selecting a frame by level is
1115 unchanged. The MI comment "-stack-select-frame" is unchanged.
1117 target remote FILENAME
1118 target extended-remote FILENAME
1119 If FILENAME is a Unix domain socket, GDB will attempt to connect
1120 to this socket instead of opening FILENAME as a character device.
1122 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1123 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1124 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1125 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1126 These commands can now print only the searched entities
1127 matching the provided regexp(s), giving a condition
1128 on the entity names or entity types. The flag -q disables
1129 printing headers or informations messages.
1135 These commands now determine the syntax for the shown entities
1136 according to the language chosen by `set language'. In particular,
1137 `set language auto' means to automatically choose the language of
1140 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1141 The 'thread apply' command accepts new FLAG arguments.
1142 FLAG arguments allow to control what output to produce and how to handle
1143 errors raised when applying COMMAND to a thread.
1145 set tui tab-width NCHARS
1146 show tui tab-width NCHARS
1147 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1149 set style enabled [on|off]
1151 Enable or disable terminal styling. Styling is enabled by default
1152 on most hosts, but disabled by default when in batch mode.
1154 set style sources [on|off]
1156 Enable or disable source code styling. Source code styling is
1157 enabled by default, but only takes effect if styling in general is
1158 enabled, and if GDB was linked with GNU Source Highlight.
1160 set style filename foreground COLOR
1161 set style filename background COLOR
1162 set style filename intensity VALUE
1163 Control the styling of file names.
1165 set style function foreground COLOR
1166 set style function background COLOR
1167 set style function intensity VALUE
1168 Control the styling of function names.
1170 set style variable foreground COLOR
1171 set style variable background COLOR
1172 set style variable intensity VALUE
1173 Control the styling of variable names.
1175 set style address foreground COLOR
1176 set style address background COLOR
1177 set style address intensity VALUE
1178 Control the styling of addresses.
1182 ** The '-data-disassemble' MI command now accepts an '-a' option to
1183 disassemble the whole function surrounding the given program
1184 counter value or function name. Support for this feature can be
1185 verified by using the "-list-features" command, which should
1186 contain "data-disassemble-a-option".
1188 ** Command responses and notifications that include a frame now include
1189 the frame's architecture in a new "arch" attribute.
1191 * New native configurations
1193 GNU/Linux/RISC-V riscv*-*-linux*
1194 FreeBSD/riscv riscv*-*-freebsd*
1198 GNU/Linux/RISC-V riscv*-*-linux*
1199 CSKY ELF csky*-*-elf
1200 CSKY GNU/LINUX csky*-*-linux
1201 FreeBSD/riscv riscv*-*-freebsd*
1203 GNU/Linux/OpenRISC or1k*-*-linux*
1207 GDB no longer supports native debugging on versions of MS-Windows
1212 ** GDB no longer supports Python versions less than 2.6.
1214 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1215 space associated to that inferior.
1217 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1218 of objfiles associated to that program space.
1220 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1221 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1224 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1225 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1226 correct and did not work properly.
1228 ** The gdb.Value type has a new constructor, which is used to construct a
1229 gdb.Value from a Python buffer object and a gdb.Type.
1235 Enable or disable the undefined behavior sanitizer. This is
1236 disabled by default, but passing --enable-ubsan=yes or
1237 --enable-ubsan=auto to configure will enable it. Enabling this can
1238 cause a performance penalty. The undefined behavior sanitizer was
1239 first introduced in GCC 4.9.
1241 *** Changes in GDB 8.2
1243 * The 'set disassembler-options' command now supports specifying options
1244 for the MIPS target.
1246 * The 'symbol-file' command now accepts an '-o' option to add a relative
1247 offset to all sections.
1249 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1250 a relative offset to all sections, but it allows to override the load
1251 address of individual sections using '-s'.
1253 * The 'add-symbol-file' command no longer requires the second argument
1254 (address of the text section).
1256 * The endianness used with the 'set endian auto' mode in the absence of
1257 an executable selected for debugging is now the last endianness chosen
1258 either by one of the 'set endian big' and 'set endian little' commands
1259 or by inferring from the last executable used, rather than the startup
1262 * The pager now allows a "c" response, meaning to disable the pager
1263 for the rest of the current command.
1265 * The commands 'info variables/functions/types' now show the source line
1266 numbers of symbol definitions when available.
1268 * 'info proc' now works on running processes on FreeBSD systems and core
1269 files created on FreeBSD systems.
1271 * C expressions can now use _Alignof, and C++ expressions can now use
1274 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1275 the vector length while the process is running.
1281 Control display of debugging info regarding the FreeBSD native target.
1283 set|show varsize-limit
1284 This new setting allows the user to control the maximum size of Ada
1285 objects being printed when those objects have a variable type,
1286 instead of that maximum size being hardcoded to 65536 bytes.
1288 set|show record btrace cpu
1289 Controls the processor to be used for enabling errata workarounds for
1290 branch trace decode.
1292 maint check libthread-db
1293 Run integrity checks on the current inferior's thread debugging
1296 maint set check-libthread-db (on|off)
1297 maint show check-libthread-db
1298 Control whether to run integrity checks on inferior specific thread
1299 debugging libraries as they are loaded. The default is not to
1300 perform such checks.
1304 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1306 ** The commands attached to a breakpoint can be set by assigning to
1307 the breakpoint's "commands" field.
1309 ** gdb.execute can now execute multi-line gdb commands.
1311 ** The new functions gdb.convenience_variable and
1312 gdb.set_convenience_variable can be used to get and set the value
1313 of convenience variables.
1315 ** A gdb.Parameter will no longer print the "set" help text on an
1316 ordinary "set"; instead by default a "set" will be silent unless
1317 the get_set_string method returns a non-empty string.
1321 RiscV ELF riscv*-*-elf
1323 * Removed targets and native configurations
1325 m88k running OpenBSD m88*-*-openbsd*
1326 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1327 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1328 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1330 * Aarch64/Linux hardware watchpoints improvements
1332 Hardware watchpoints on unaligned addresses are now properly
1333 supported when running Linux kernel 4.10 or higher: read and access
1334 watchpoints are no longer spuriously missed, and all watchpoints
1335 lengths between 1 and 8 bytes are supported. On older kernels,
1336 watchpoints set on unaligned addresses are no longer missed, with
1337 the tradeoff that there is a possibility of false hits being
1342 --enable-codesign=CERT
1343 This can be used to invoke "codesign -s CERT" after building gdb.
1344 This option is useful on macOS, where code signing is required for
1345 gdb to work properly.
1347 --disable-gdbcli has been removed
1348 This is now silently accepted, but does nothing.
1350 *** Changes in GDB 8.1
1352 * GDB now supports dynamically creating arbitrary register groups specified
1353 in XML target descriptions. This allows for finer grain grouping of
1354 registers on systems with a large amount of registers.
1356 * The 'ptype' command now accepts a '/o' flag, which prints the
1357 offsets and sizes of fields in a struct, like the pahole(1) tool.
1359 * New "--readnever" command line option instructs GDB to not read each
1360 symbol file's symbolic debug information. This makes startup faster
1361 but at the expense of not being able to perform symbolic debugging.
1362 This option is intended for use cases where symbolic debugging will
1363 not be used, e.g., when you only need to dump the debuggee's core.
1365 * GDB now uses the GNU MPFR library, if available, to emulate target
1366 floating-point arithmetic during expression evaluation when the target
1367 uses different floating-point formats than the host. At least version
1368 3.1 of GNU MPFR is required.
1370 * GDB now supports access to the guarded-storage-control registers and the
1371 software-based guarded-storage broadcast control registers on IBM z14.
1373 * On Unix systems, GDB now supports transmitting environment variables
1374 that are to be set or unset to GDBserver. These variables will
1375 affect the environment to be passed to the remote inferior.
1377 To inform GDB of environment variables that are to be transmitted to
1378 GDBserver, use the "set environment" command. Only user set
1379 environment variables are sent to GDBserver.
1381 To inform GDB of environment variables that are to be unset before
1382 the remote inferior is started by the GDBserver, use the "unset
1383 environment" command.
1385 * Completion improvements
1387 ** GDB can now complete function parameters in linespecs and
1388 explicit locations without quoting. When setting breakpoints,
1389 quoting around functions names to help with TAB-completion is
1390 generally no longer necessary. For example, this now completes
1393 (gdb) b function(in[TAB]
1394 (gdb) b function(int)
1396 Related, GDB is no longer confused with completing functions in
1397 C++ anonymous namespaces:
1400 (gdb) b (anonymous namespace)::[TAB][TAB]
1401 (anonymous namespace)::a_function()
1402 (anonymous namespace)::b_function()
1404 ** GDB now has much improved linespec and explicit locations TAB
1405 completion support, that better understands what you're
1406 completing and offers better suggestions. For example, GDB no
1407 longer offers data symbols as possible completions when you're
1408 setting a breakpoint.
1410 ** GDB now TAB-completes label symbol names.
1412 ** The "complete" command now mimics TAB completion accurately.
1414 * New command line options (gcore)
1417 Dump all memory mappings.
1419 * Breakpoints on C++ functions are now set on all scopes by default
1421 By default, breakpoints on functions/methods are now interpreted as
1422 specifying all functions with the given name ignoring missing
1423 leading scopes (namespaces and classes).
1425 For example, assuming a C++ program with symbols named:
1430 both commands "break func()" and "break B::func()" set a breakpoint
1433 You can use the new flag "-qualified" to override this. This makes
1434 GDB interpret the specified function name as a complete
1435 fully-qualified name instead. For example, using the same C++
1436 program, the "break -q B::func" command sets a breakpoint on
1437 "B::func", only. A parameter has been added to the Python
1438 gdb.Breakpoint constructor to achieve the same result when creating
1439 a breakpoint from Python.
1441 * Breakpoints on functions marked with C++ ABI tags
1443 GDB can now set breakpoints on functions marked with C++ ABI tags
1444 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1445 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1447 Functions with a C++11 abi tag are demangled/displayed like this:
1449 function[abi:cxx11](int)
1452 You can now set a breakpoint on such functions simply as if they had
1455 (gdb) b function(int)
1457 Or if you need to disambiguate between tags, like:
1459 (gdb) b function[abi:other_tag](int)
1461 Tab completion was adjusted accordingly as well.
1465 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1466 gdb.new_thread are emitted. See the manual for further
1467 description of these.
1469 ** A new function, "gdb.rbreak" has been added to the Python API.
1470 This function allows the setting of a large number of breakpoints
1471 via a regex pattern in Python. See the manual for further details.
1473 ** Python breakpoints can now accept explicit locations. See the
1474 manual for a further description of this feature.
1477 * New features in the GDB remote stub, GDBserver
1479 ** GDBserver is now able to start inferior processes with a
1480 specified initial working directory.
1482 The user can set the desired working directory to be used from
1483 GDB using the new "set cwd" command.
1485 ** New "--selftest" command line option runs some GDBserver self
1486 tests. These self tests are disabled in releases.
1488 ** On Unix systems, GDBserver now does globbing expansion and variable
1489 substitution in inferior command line arguments.
1491 This is done by starting inferiors using a shell, like GDB does.
1492 See "set startup-with-shell" in the user manual for how to disable
1493 this from GDB when using "target extended-remote". When using
1494 "target remote", you can disable the startup with shell by using the
1495 new "--no-startup-with-shell" GDBserver command line option.
1497 ** On Unix systems, GDBserver now supports receiving environment
1498 variables that are to be set or unset from GDB. These variables
1499 will affect the environment to be passed to the inferior.
1501 * When catching an Ada exception raised with a message, GDB now prints
1502 the message in the catchpoint hit notification. In GDB/MI mode, that
1503 information is provided as an extra field named "exception-message"
1504 in the *stopped notification.
1506 * Trait objects can now be inspected When debugging Rust code. This
1507 requires compiler support which will appear in Rust 1.24.
1509 * New remote packets
1511 QEnvironmentHexEncoded
1512 Inform GDBserver of an environment variable that is to be passed to
1513 the inferior when starting it.
1516 Inform GDBserver of an environment variable that is to be unset
1517 before starting the remote inferior.
1520 Inform GDBserver that the environment should be reset (i.e.,
1521 user-set environment variables should be unset).
1524 Indicates whether the inferior must be started with a shell or not.
1527 Tell GDBserver that the inferior to be started should use a specific
1530 * The "maintenance print c-tdesc" command now takes an optional
1531 argument which is the file name of XML target description.
1533 * The "maintenance selftest" command now takes an optional argument to
1534 filter the tests to be run.
1536 * The "enable", and "disable" commands now accept a range of
1537 breakpoint locations, e.g. "enable 1.3-5".
1542 Set and show the current working directory for the inferior.
1544 set|show compile-gcc
1545 Set and show compilation command used for compiling and injecting code
1546 with the 'compile' commands.
1548 set debug separate-debug-file
1549 show debug separate-debug-file
1550 Control the display of debug output about separate debug file search.
1552 set dump-excluded-mappings
1553 show dump-excluded-mappings
1554 Control whether mappings marked with the VM_DONTDUMP flag should be
1555 dumped when generating a core file.
1557 maint info selftests
1558 List the registered selftests.
1561 Start the debugged program stopping at the first instruction.
1564 Control display of debugging messages related to OpenRISC targets.
1566 set|show print type nested-type-limit
1567 Set and show the limit of nesting level for nested types that the
1568 type printer will show.
1570 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1573 * Safer/improved support for debugging with no debug info
1575 GDB no longer assumes functions with no debug information return
1578 This means that GDB now refuses to call such functions unless you
1579 tell it the function's type, by either casting the call to the
1580 declared return type, or by casting the function to a function
1581 pointer of the right type, and calling that:
1583 (gdb) p getenv ("PATH")
1584 'getenv' has unknown return type; cast the call to its declared return type
1585 (gdb) p (char *) getenv ("PATH")
1586 $1 = 0x7fffffffe "/usr/local/bin:/"...
1587 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1588 $2 = 0x7fffffffe "/usr/local/bin:/"...
1590 Similarly, GDB no longer assumes that global variables with no debug
1591 info have type 'int', and refuses to print the variable's value
1592 unless you tell it the variable's type:
1595 'var' has unknown type; cast it to its declared type
1599 * New native configurations
1601 FreeBSD/aarch64 aarch64*-*-freebsd*
1602 FreeBSD/arm arm*-*-freebsd*
1606 FreeBSD/aarch64 aarch64*-*-freebsd*
1607 FreeBSD/arm arm*-*-freebsd*
1608 OpenRISC ELF or1k*-*-elf
1610 * Removed targets and native configurations
1612 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1614 *** Changes in GDB 8.0
1616 * GDB now supports access to the PKU register on GNU/Linux. The register is
1617 added by the Memory Protection Keys for Userspace feature which will be
1618 available in future Intel CPUs.
1620 * GDB now supports C++11 rvalue references.
1624 ** New functions to start, stop and access a running btrace recording.
1625 ** Rvalue references are now supported in gdb.Type.
1627 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1630 * Building GDB and GDBserver now requires a C++11 compiler.
1632 For example, GCC 4.8 or later.
1634 It is no longer possible to build GDB or GDBserver with a C
1635 compiler. The --disable-build-with-cxx configure option has been
1638 * Building GDB and GDBserver now requires GNU make >= 3.81.
1640 It is no longer supported to build GDB or GDBserver with another
1641 implementation of the make program or an earlier version of GNU make.
1643 * Native debugging on MS-Windows supports command-line redirection
1645 Command-line arguments used for starting programs on MS-Windows can
1646 now include redirection symbols supported by native Windows shells,
1647 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1648 as "run", "start", and "set args", as well as the corresponding MI
1651 * Support for thread names on MS-Windows.
1653 GDB now catches and handles the special exception that programs
1654 running on MS-Windows use to assign names to threads in the
1657 * Support for Java programs compiled with gcj has been removed.
1659 * User commands now accept an unlimited number of arguments.
1660 Previously, only up to 10 was accepted.
1662 * The "eval" command now expands user-defined command arguments.
1664 This makes it easier to process a variable number of arguments:
1669 eval "print $arg%d", $i
1674 * Target descriptions can now describe registers for sparc32 and sparc64.
1676 * GDB now supports DWARF version 5 (debug information format).
1677 Its .debug_names index is not yet supported.
1679 * New native configurations
1681 FreeBSD/mips mips*-*-freebsd
1685 Synopsys ARC arc*-*-elf32
1686 FreeBSD/mips mips*-*-freebsd
1688 * Removed targets and native configurations
1690 Alpha running FreeBSD alpha*-*-freebsd*
1691 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1696 Erases all the flash memory regions reported by the target.
1698 maint print arc arc-instruction address
1699 Print internal disassembler information about instruction at a given address.
1703 set disassembler-options
1704 show disassembler-options
1705 Controls the passing of target specific information to the disassembler.
1706 If it is necessary to specify more than one disassembler option then
1707 multiple options can be placed together into a comma separated list.
1708 The default value is the empty string. Currently, the only supported
1709 targets are ARM, PowerPC and S/390.
1714 Erases all the flash memory regions reported by the target. This is
1715 equivalent to the CLI command flash-erase.
1717 -file-list-shared-libraries
1718 List the shared libraries in the program. This is
1719 equivalent to the CLI command "info shared".
1722 Catchpoints stopping the program when Ada exceptions are
1723 handled. This is equivalent to the CLI command "catch handlers".
1725 *** Changes in GDB 7.12
1727 * GDB and GDBserver now build with a C++ compiler by default.
1729 The --enable-build-with-cxx configure option is now enabled by
1730 default. One must now explicitly configure with
1731 --disable-build-with-cxx in order to build with a C compiler. This
1732 option will be removed in a future release.
1734 * GDBserver now supports recording btrace without maintaining an active
1737 * GDB now supports a negative repeat count in the 'x' command to examine
1738 memory backward from the given address. For example:
1741 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1742 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1743 (gdb) x/-5i 0x0000000000400580
1744 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1745 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1746 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1747 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1748 0x40057b <main(int, char**)+25>:
1749 callq 0x400536 <Func1(int, char const*)>
1751 * Fortran: Support structures with fields of dynamic types and
1752 arrays of dynamic types.
1754 * The symbol dumping maintenance commands have new syntax.
1755 maint print symbols [-pc address] [--] [filename]
1756 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1757 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1758 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1759 maint print msymbols [-objfile objfile] [--] [filename]
1761 * GDB now supports multibit bitfields and enums in target register
1764 * New Python-based convenience function $_as_string(val), which returns
1765 the textual representation of a value. This function is especially
1766 useful to obtain the text label of an enum value.
1768 * Intel MPX bound violation handling.
1770 Segmentation faults caused by a Intel MPX boundary violation
1771 now display the kind of violation (upper or lower), the memory
1772 address accessed and the memory bounds, along with the usual
1773 signal received and code location.
1777 Program received signal SIGSEGV, Segmentation fault
1778 Upper bound violation while accessing address 0x7fffffffc3b3
1779 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1780 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1782 * Rust language support.
1783 GDB now supports debugging programs written in the Rust programming
1784 language. See https://www.rust-lang.org/ for more information about
1787 * Support for running interpreters on specified input/output devices
1789 GDB now supports a new mechanism that allows frontends to provide
1790 fully featured GDB console views, as a better alternative to
1791 building such views on top of the "-interpreter-exec console"
1792 command. See the new "new-ui" command below. With that command,
1793 frontends can now start GDB in the traditional command-line mode
1794 running in an embedded terminal emulator widget, and create a
1795 separate MI interpreter running on a specified i/o device. In this
1796 way, GDB handles line editing, history, tab completion, etc. in the
1797 console all by itself, and the GUI uses the separate MI interpreter
1798 for its own control and synchronization, invisible to the command
1801 * The "catch syscall" command catches groups of related syscalls.
1803 The "catch syscall" command now supports catching a group of related
1804 syscalls using the 'group:' or 'g:' prefix.
1809 skip -gfile file-glob-pattern
1810 skip -function function
1811 skip -rfunction regular-expression
1812 A generalized form of the skip command, with new support for
1813 glob-style file names and regular expressions for function names.
1814 Additionally, a file spec and a function spec may now be combined.
1816 maint info line-table REGEXP
1817 Display the contents of GDB's internal line table data structure.
1820 Run any GDB unit tests that were compiled in.
1823 Start a new user interface instance running INTERP as interpreter,
1824 using the TTY file for input/output.
1828 ** gdb.Breakpoint objects have a new attribute "pending", which
1829 indicates whether the breakpoint is pending.
1830 ** Three new breakpoint-related events have been added:
1831 gdb.breakpoint_created, gdb.breakpoint_modified, and
1832 gdb.breakpoint_deleted.
1834 signal-event EVENTID
1835 Signal ("set") the given MS-Windows event object. This is used in
1836 conjunction with the Windows JIT debugging (AeDebug) support, where
1837 the OS suspends a crashing process until a debugger can attach to
1838 it. Resuming the crashing process, in order to debug it, is done by
1839 signalling an event.
1841 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1842 was added in GDBserver, including JIT compiling fast tracepoint's
1843 conditional expression bytecode into native code.
1845 * Support for various remote target protocols and ROM monitors has
1848 target m32rsdi Remote M32R debugging over SDI
1849 target mips MIPS remote debugging protocol
1850 target pmon PMON ROM monitor
1851 target ddb NEC's DDB variant of PMON for Vr4300
1852 target rockhopper NEC RockHopper variant of PMON
1853 target lsi LSI variant of PMO
1855 * Support for tracepoints and fast tracepoints on powerpc-linux,
1856 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1857 including JIT compiling fast tracepoint's conditional expression
1858 bytecode into native code.
1860 * MI async record =record-started now includes the method and format used for
1861 recording. For example:
1863 =record-started,thread-group="i1",method="btrace",format="bts"
1865 * MI async record =thread-selected now includes the frame field. For example:
1867 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1871 Andes NDS32 nds32*-*-elf
1873 *** Changes in GDB 7.11
1875 * GDB now supports debugging kernel-based threads on FreeBSD.
1877 * Per-inferior thread numbers
1879 Thread numbers are now per inferior instead of global. If you're
1880 debugging multiple inferiors, GDB displays thread IDs using a
1881 qualified INF_NUM.THR_NUM form. For example:
1885 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1886 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1887 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1888 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1890 As consequence, thread numbers as visible in the $_thread
1891 convenience variable and in Python's InferiorThread.num attribute
1892 are no longer unique between inferiors.
1894 GDB now maintains a second thread ID per thread, referred to as the
1895 global thread ID, which is the new equivalent of thread numbers in
1896 previous releases. See also $_gthread below.
1898 For backwards compatibility, MI's thread IDs always refer to global
1901 * Commands that accept thread IDs now accept the qualified
1902 INF_NUM.THR_NUM form as well. For example:
1905 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1908 * In commands that accept a list of thread IDs, you can now refer to
1909 all threads of an inferior using a star wildcard. GDB accepts
1910 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1911 refer to all threads of the current inferior. For example, "info
1914 * You can use "info threads -gid" to display the global thread ID of
1917 * The new convenience variable $_gthread holds the global number of
1920 * The new convenience variable $_inferior holds the number of the
1923 * GDB now displays the ID and name of the thread that hit a breakpoint
1924 or received a signal, if your program is multi-threaded. For
1927 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1928 Thread 1 "main" received signal SIGINT, Interrupt.
1930 * Record btrace now supports non-stop mode.
1932 * Support for tracepoints on aarch64-linux was added in GDBserver.
1934 * The 'record instruction-history' command now indicates speculative execution
1935 when using the Intel Processor Trace recording format.
1937 * GDB now allows users to specify explicit locations, bypassing
1938 the linespec parser. This feature is also available to GDB/MI
1941 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1942 GDB now is able to debug both AArch64 applications and ARM applications
1945 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1946 including JIT compiling fast tracepoint's conditional expression bytecode
1949 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1951 * "info threads", "info inferiors", "info display", "info checkpoints"
1952 and "maint info program-spaces" now list the corresponding items in
1953 ascending ID order, for consistency with all other "info" commands.
1955 * In Ada, the overloads selection menu has been enhanced to display the
1956 parameter types and the return types for the matching overloaded subprograms.
1960 maint set target-non-stop (on|off|auto)
1961 maint show target-non-stop
1962 Control whether GDB targets always operate in non-stop mode even if
1963 "set non-stop" is "off". The default is "auto", meaning non-stop
1964 mode is enabled if supported by the target.
1966 maint set bfd-sharing
1967 maint show bfd-sharing
1968 Control the reuse of bfd objects.
1971 show debug bfd-cache
1972 Control display of debugging info regarding bfd caching.
1976 Control display of debugging info regarding FreeBSD threads.
1978 set remote multiprocess-extensions-packet
1979 show remote multiprocess-extensions-packet
1980 Set/show the use of the remote protocol multiprocess extensions.
1982 set remote thread-events
1983 show remote thread-events
1984 Set/show the use of thread create/exit events.
1986 set ada print-signatures on|off
1987 show ada print-signatures"
1988 Control whether parameter types and return types are displayed in overloads
1989 selection menus. It is activated (@code{on}) by default.
1993 Controls the maximum size of memory, in bytes, that GDB will
1994 allocate for value contents. Prevents incorrect programs from
1995 causing GDB to allocate overly large buffers. Default is 64k.
1997 * The "disassemble" command accepts a new modifier: /s.
1998 It prints mixed source+disassembly like /m with two differences:
1999 - disassembled instructions are now printed in program order, and
2000 - and source for all relevant files is now printed.
2001 The "/m" option is now considered deprecated: its "source-centric"
2002 output hasn't proved useful in practice.
2004 * The "record instruction-history" command accepts a new modifier: /s.
2005 It behaves exactly like /m and prints mixed source+disassembly.
2007 * The "set scheduler-locking" command supports a new mode "replay".
2008 It behaves like "off" in record mode and like "on" in replay mode.
2010 * Support for various ROM monitors has been removed:
2012 target dbug dBUG ROM monitor for Motorola ColdFire
2013 target picobug Motorola picobug monitor
2014 target dink32 DINK32 ROM monitor for PowerPC
2015 target m32r Renesas M32R/D ROM monitor
2016 target mon2000 mon2000 ROM monitor
2017 target ppcbug PPCBUG ROM monitor for PowerPC
2019 * Support for reading/writing memory and extracting values on architectures
2020 whose memory is addressable in units of any integral multiple of 8 bits.
2023 Allows to break when an Ada exception is handled.
2025 * New remote packets
2028 Indicates that an exec system call was executed.
2030 exec-events feature in qSupported
2031 The qSupported packet allows GDB to request support for exec
2032 events using the new 'gdbfeature' exec-event, and the qSupported
2033 response can contain the corresponding 'stubfeature'. Set and
2034 show commands can be used to display whether these features are enabled.
2037 Equivalent to interrupting with the ^C character, but works in
2040 thread created stop reason (T05 create:...)
2041 Indicates that the thread was just created and is stopped at entry.
2043 thread exit stop reply (w exitcode;tid)
2044 Indicates that the thread has terminated.
2047 Enables/disables thread create and exit event reporting. For
2048 example, this is used in non-stop mode when GDB stops a set of
2049 threads and synchronously waits for the their corresponding stop
2050 replies. Without exit events, if one of the threads exits, GDB
2051 would hang forever not knowing that it should no longer expect a
2052 stop for that same thread.
2055 Indicates that there are no resumed threads left in the target (all
2056 threads are stopped). The remote stub reports support for this stop
2057 reply to GDB's qSupported query.
2060 Enables/disables catching syscalls from the inferior process.
2061 The remote stub reports support for this packet to GDB's qSupported query.
2063 syscall_entry stop reason
2064 Indicates that a syscall was just called.
2066 syscall_return stop reason
2067 Indicates that a syscall just returned.
2069 * Extended-remote exec events
2071 ** GDB now has support for exec events on extended-remote Linux targets.
2072 For such targets with Linux kernels 2.5.46 and later, this enables
2073 follow-exec-mode and exec catchpoints.
2075 set remote exec-event-feature-packet
2076 show remote exec-event-feature-packet
2077 Set/show the use of the remote exec event feature.
2079 * Thread names in remote protocol
2081 The reply to qXfer:threads:read may now include a name attribute for each
2084 * Target remote mode fork and exec events
2086 ** GDB now has support for fork and exec events on target remote mode
2087 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2088 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2089 fork and exec catchpoints.
2091 * Remote syscall events
2093 ** GDB now has support for catch syscall on remote Linux targets,
2094 currently enabled on x86/x86_64 architectures.
2096 set remote catch-syscall-packet
2097 show remote catch-syscall-packet
2098 Set/show the use of the remote catch syscall feature.
2102 ** The -var-set-format command now accepts the zero-hexadecimal
2103 format. It outputs data in hexadecimal format with zero-padding on the
2108 ** gdb.InferiorThread objects have a new attribute "global_num",
2109 which refers to the thread's global thread ID. The existing
2110 "num" attribute now refers to the thread's per-inferior number.
2111 See "Per-inferior thread numbers" above.
2112 ** gdb.InferiorThread objects have a new attribute "inferior", which
2113 is the Inferior object the thread belongs to.
2115 *** Changes in GDB 7.10
2117 * Support for process record-replay and reverse debugging on aarch64*-linux*
2118 targets has been added. GDB now supports recording of A64 instruction set
2119 including advance SIMD instructions.
2121 * Support for Sun's version of the "stabs" debug file format has been removed.
2123 * GDB now honors the content of the file /proc/PID/coredump_filter
2124 (PID is the process ID) on GNU/Linux systems. This file can be used
2125 to specify the types of memory mappings that will be included in a
2126 corefile. For more information, please refer to the manual page of
2127 "core(5)". GDB also has a new command: "set use-coredump-filter
2128 on|off". It allows to set whether GDB will read the content of the
2129 /proc/PID/coredump_filter file when generating a corefile.
2131 * The "info os" command on GNU/Linux can now display information on
2133 "info os cpus" Listing of all cpus/cores on the system
2135 * GDB has two new commands: "set serial parity odd|even|none" and
2136 "show serial parity". These allows to set or show parity for the
2139 * The "info source" command now displays the producer string if it was
2140 present in the debug info. This typically includes the compiler version
2141 and may include things like its command line arguments.
2143 * The "info dll", an alias of the "info sharedlibrary" command,
2144 is now available on all platforms.
2146 * Directory names supplied to the "set sysroot" commands may be
2147 prefixed with "target:" to tell GDB to access shared libraries from
2148 the target system, be it local or remote. This replaces the prefix
2149 "remote:". The default sysroot has been changed from "" to
2150 "target:". "remote:" is automatically converted to "target:" for
2151 backward compatibility.
2153 * The system root specified by "set sysroot" will be prepended to the
2154 filename of the main executable (if reported to GDB as absolute by
2155 the operating system) when starting processes remotely, and when
2156 attaching to already-running local or remote processes.
2158 * GDB now supports automatic location and retrieval of executable
2159 files from remote targets. Remote debugging can now be initiated
2160 using only a "target remote" or "target extended-remote" command
2161 (no "set sysroot" or "file" commands are required). See "New remote
2164 * The "dump" command now supports verilog hex format.
2166 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2168 * On GNU/Linux, GDB and gdbserver are now able to access executable
2169 and shared library files without a "set sysroot" command when
2170 attaching to processes running in different mount namespaces from
2171 the debugger. This makes it possible to attach to processes in
2172 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2173 See "New remote packets" below.
2175 * The "tui reg" command now provides completion for all of the
2176 available register groups, including target specific groups.
2178 * The HISTSIZE environment variable is no longer read when determining
2179 the size of GDB's command history. GDB now instead reads the dedicated
2180 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2181 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2186 ** Memory ports can now be unbuffered.
2190 ** gdb.Objfile objects have a new attribute "username",
2191 which is the name of the objfile as specified by the user,
2192 without, for example, resolving symlinks.
2193 ** You can now write frame unwinders in Python.
2194 ** gdb.Type objects have a new method "optimized_out",
2195 returning optimized out gdb.Value instance of this type.
2196 ** gdb.Value objects have new methods "reference_value" and
2197 "const_value" which return a reference to the value and a
2198 "const" version of the value respectively.
2202 maint print symbol-cache
2203 Print the contents of the symbol cache.
2205 maint print symbol-cache-statistics
2206 Print statistics of symbol cache usage.
2208 maint flush-symbol-cache
2209 Flush the contents of the symbol cache.
2213 Start branch trace recording using Branch Trace Store (BTS) format.
2216 Evaluate expression by using the compiler and print result.
2220 Explicit commands for enabling and disabling tui mode.
2223 set mpx bound on i386 and amd64
2224 Support for bound table investigation on Intel MPX enabled applications.
2228 Start branch trace recording using Intel Processor Trace format.
2231 Print information about branch tracing internals.
2233 maint btrace packet-history
2234 Print the raw branch tracing data.
2236 maint btrace clear-packet-history
2237 Discard the stored raw branch tracing data.
2240 Discard all branch tracing data. It will be fetched and processed
2241 anew by the next "record" command.
2246 Renamed from "set debug dwarf2-die".
2247 show debug dwarf-die
2248 Renamed from "show debug dwarf2-die".
2250 set debug dwarf-read
2251 Renamed from "set debug dwarf2-read".
2252 show debug dwarf-read
2253 Renamed from "show debug dwarf2-read".
2255 maint set dwarf always-disassemble
2256 Renamed from "maint set dwarf2 always-disassemble".
2257 maint show dwarf always-disassemble
2258 Renamed from "maint show dwarf2 always-disassemble".
2260 maint set dwarf max-cache-age
2261 Renamed from "maint set dwarf2 max-cache-age".
2262 maint show dwarf max-cache-age
2263 Renamed from "maint show dwarf2 max-cache-age".
2265 set debug dwarf-line
2266 show debug dwarf-line
2267 Control display of debugging info regarding DWARF line processing.
2270 show max-completions
2271 Set the maximum number of candidates to be considered during
2272 completion. The default value is 200. This limit allows GDB
2273 to avoid generating large completion lists, the computation of
2274 which can cause the debugger to become temporarily unresponsive.
2276 set history remove-duplicates
2277 show history remove-duplicates
2278 Control the removal of duplicate history entries.
2280 maint set symbol-cache-size
2281 maint show symbol-cache-size
2282 Control the size of the symbol cache.
2284 set|show record btrace bts buffer-size
2285 Set and show the size of the ring buffer used for branch tracing in
2287 The obtained size may differ from the requested size. Use "info
2288 record" to see the obtained buffer size.
2290 set debug linux-namespaces
2291 show debug linux-namespaces
2292 Control display of debugging info regarding Linux namespaces.
2294 set|show record btrace pt buffer-size
2295 Set and show the size of the ring buffer used for branch tracing in
2296 Intel Processor Trace format.
2297 The obtained size may differ from the requested size. Use "info
2298 record" to see the obtained buffer size.
2300 maint set|show btrace pt skip-pad
2301 Set and show whether PAD packets are skipped when computing the
2304 * The command 'thread apply all' can now support new option '-ascending'
2305 to call its specified command for all threads in ascending order.
2307 * Python/Guile scripting
2309 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2310 special section named `.debug_gdb_scripts'.
2312 * New remote packets
2314 qXfer:btrace-conf:read
2315 Return the branch trace configuration for the current thread.
2317 Qbtrace-conf:bts:size
2318 Set the requested ring buffer size for branch tracing in BTS format.
2321 Enable Intel Processor Trace-based branch tracing for the current
2322 process. The remote stub reports support for this packet to GDB's
2325 Qbtrace-conf:pt:size
2326 Set the requested ring buffer size for branch tracing in Intel Processor
2330 Indicates a memory breakpoint instruction was executed, irrespective
2331 of whether it was GDB that planted the breakpoint or the breakpoint
2332 is hardcoded in the program. This is required for correct non-stop
2336 Indicates the target stopped for a hardware breakpoint. This is
2337 required for correct non-stop mode operation.
2340 Return information about files on the remote system.
2342 qXfer:exec-file:read
2343 Return the full absolute name of the file that was executed to
2344 create a process running on the remote system.
2347 Select the filesystem on which vFile: operations with filename
2348 arguments will operate. This is required for GDB to be able to
2349 access files on remote targets where the remote stub does not
2350 share a common filesystem with the inferior(s).
2353 Indicates that a fork system call was executed.
2356 Indicates that a vfork system call was executed.
2358 vforkdone stop reason
2359 Indicates that a vfork child of the specified process has executed
2360 an exec or exit, allowing the vfork parent to resume execution.
2362 fork-events and vfork-events features in qSupported
2363 The qSupported packet allows GDB to request support for fork and
2364 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2365 and the qSupported response can contain the corresponding
2366 'stubfeatures'. Set and show commands can be used to display
2367 whether these features are enabled.
2369 * Extended-remote fork events
2371 ** GDB now has support for fork events on extended-remote Linux
2372 targets. For targets with Linux kernels 2.5.60 and later, this
2373 enables follow-fork-mode and detach-on-fork for both fork and
2374 vfork, as well as fork and vfork catchpoints.
2376 * The info record command now shows the recording format and the
2377 branch tracing configuration for the current thread when using
2378 the btrace record target.
2379 For the BTS format, it shows the ring buffer size.
2381 * GDB now has support for DTrace USDT (Userland Static Defined
2382 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2384 * GDB now supports access to vector registers on S/390 GNU/Linux
2387 * Removed command line options
2389 -xdb HP-UX XDB compatibility mode.
2391 * Removed targets and native configurations
2393 HP/PA running HP-UX hppa*-*-hpux*
2394 Itanium running HP-UX ia64-*-hpux*
2396 * New configure options
2399 This configure option allows the user to build GDB with support for
2400 Intel Processor Trace (default: auto). This requires libipt.
2402 --with-libipt-prefix=PATH
2403 Specify the path to the version of libipt that GDB should use.
2404 $PATH/include should contain the intel-pt.h header and
2405 $PATH/lib should contain the libipt.so library.
2407 *** Changes in GDB 7.9.1
2411 ** Xmethods can now specify a result type.
2413 *** Changes in GDB 7.9
2415 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2419 ** You can now access frame registers from Python scripts.
2420 ** New attribute 'producer' for gdb.Symtab objects.
2421 ** gdb.Objfile objects have a new attribute "progspace",
2422 which is the gdb.Progspace object of the containing program space.
2423 ** gdb.Objfile objects have a new attribute "owner".
2424 ** gdb.Objfile objects have a new attribute "build_id",
2425 which is the build ID generated when the file was built.
2426 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2427 ** A new event "gdb.clear_objfiles" has been added, triggered when
2428 selecting a new file to debug.
2429 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2430 ** New function gdb.lookup_objfile.
2432 New events which are triggered when GDB modifies the state of the
2435 ** gdb.events.inferior_call_pre: Function call is about to be made.
2436 ** gdb.events.inferior_call_post: Function call has just been made.
2437 ** gdb.events.memory_changed: A memory location has been altered.
2438 ** gdb.events.register_changed: A register has been altered.
2440 * New Python-based convenience functions:
2442 ** $_caller_is(name [, number_of_frames])
2443 ** $_caller_matches(regexp [, number_of_frames])
2444 ** $_any_caller_is(name [, number_of_frames])
2445 ** $_any_caller_matches(regexp [, number_of_frames])
2447 * GDB now supports the compilation and injection of source code into
2448 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2449 to compile the source code to object code, and if successful, inject
2450 and execute that code within the current context of the inferior.
2451 Currently the C language is supported. The commands used to
2452 interface with this new feature are:
2454 compile code [-raw|-r] [--] [source code]
2455 compile file [-raw|-r] filename
2459 demangle [-l language] [--] name
2460 Demangle "name" in the specified language, or the current language
2461 if elided. This command is renamed from the "maint demangle" command.
2462 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2463 as "maint demangler-warning".
2465 queue-signal signal-name-or-number
2466 Queue a signal to be delivered to the thread when it is resumed.
2468 add-auto-load-scripts-directory directory
2469 Add entries to the list of directories from which to load auto-loaded
2472 maint print user-registers
2473 List all currently available "user" registers.
2475 compile code [-r|-raw] [--] [source code]
2476 Compile, inject, and execute in the inferior the executable object
2477 code produced by compiling the provided source code.
2479 compile file [-r|-raw] filename
2480 Compile and inject into the inferior the executable object code
2481 produced by compiling the source code stored in the filename
2484 * On resume, GDB now always passes the signal the program had stopped
2485 for to the thread the signal was sent to, even if the user changed
2486 threads before resuming. Previously GDB would often (but not
2487 always) deliver the signal to the thread that happens to be current
2490 * Conversely, the "signal" command now consistently delivers the
2491 requested signal to the current thread. GDB now asks for
2492 confirmation if the program had stopped for a signal and the user
2493 switched threads meanwhile.
2495 * "breakpoint always-inserted" modes "off" and "auto" merged.
2497 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2498 won't remove breakpoints from the target until all threads stop,
2499 even in non-stop mode. The "auto" mode has been removed, and "off"
2500 is now the default mode.
2504 set debug symbol-lookup
2505 show debug symbol-lookup
2506 Control display of debugging info regarding symbol lookup.
2510 ** The -list-thread-groups command outputs an exit-code field for
2511 inferiors that have exited.
2515 MIPS SDE mips*-sde*-elf*
2519 Support for these obsolete configurations has been removed.
2521 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2522 SGI Irix-5.x mips-*-irix5*
2523 SGI Irix-6.x mips-*-irix6*
2524 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2525 VAX running Ultrix vax-*-ultrix*
2527 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2528 and "assf"), have been removed. Use the "sharedlibrary" command, or
2529 its alias "share", instead.
2531 *** Changes in GDB 7.8
2533 * New command line options
2536 This is an alias for the --data-directory option.
2538 * GDB supports printing and modifying of variable length automatic arrays
2539 as specified in ISO C99.
2541 * The ARM simulator now supports instruction level tracing
2542 with or without disassembly.
2546 GDB now has support for scripting using Guile. Whether this is
2547 available is determined at configure time.
2548 Guile version 2.0 or greater is required.
2549 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2551 * New commands (for set/show, see "New options" below)
2555 Invoke CODE by passing it to the Guile interpreter.
2559 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2561 info auto-load guile-scripts [regexp]
2562 Print the list of automatically loaded Guile scripts.
2564 * The source command is now capable of sourcing Guile scripts.
2565 This feature is dependent on the debugger being built with Guile support.
2569 set print symbol-loading (off|brief|full)
2570 show print symbol-loading
2571 Control whether to print informational messages when loading symbol
2572 information for a file. The default is "full", but when debugging
2573 programs with large numbers of shared libraries the amount of output
2574 becomes less useful.
2576 set guile print-stack (none|message|full)
2577 show guile print-stack
2578 Show a stack trace when an error is encountered in a Guile script.
2580 set auto-load guile-scripts (on|off)
2581 show auto-load guile-scripts
2582 Control auto-loading of Guile script files.
2584 maint ada set ignore-descriptive-types (on|off)
2585 maint ada show ignore-descriptive-types
2586 Control whether the debugger should ignore descriptive types in Ada
2587 programs. The default is not to ignore the descriptive types. See
2588 the user manual for more details on descriptive types and the intended
2589 usage of this option.
2591 set auto-connect-native-target
2593 Control whether GDB is allowed to automatically connect to the
2594 native target for the run, attach, etc. commands when not connected
2595 to any target yet. See also "target native" below.
2597 set record btrace replay-memory-access (read-only|read-write)
2598 show record btrace replay-memory-access
2599 Control what memory accesses are allowed during replay.
2601 maint set target-async (on|off)
2602 maint show target-async
2603 This controls whether GDB targets operate in synchronous or
2604 asynchronous mode. Normally the default is asynchronous, if it is
2605 available; but this can be changed to more easily debug problems
2606 occurring only in synchronous mode.
2608 set mi-async (on|off)
2610 Control whether MI asynchronous mode is preferred. This supersedes
2611 "set target-async" of previous GDB versions.
2613 * "set target-async" is deprecated as a CLI option and is now an alias
2614 for "set mi-async" (only puts MI into async mode).
2616 * Background execution commands (e.g., "c&", "s&", etc.) are now
2617 possible ``out of the box'' if the target supports them. Previously
2618 the user would need to explicitly enable the possibility with the
2619 "set target-async on" command.
2621 * New features in the GDB remote stub, GDBserver
2623 ** New option --debug-format=option1[,option2,...] allows one to add
2624 additional text to each output. At present only timestamps
2625 are supported: --debug-format=timestamps.
2626 Timestamps can also be turned on with the
2627 "monitor set debug-format timestamps" command from GDB.
2629 * The 'record instruction-history' command now starts counting instructions
2630 at one. This also affects the instruction ranges reported by the
2631 'record function-call-history' command when given the /i modifier.
2633 * The command 'record function-call-history' supports a new modifier '/c' to
2634 indent the function names based on their call stack depth.
2635 The fields for the '/i' and '/l' modifier have been reordered.
2636 The source line range is now prefixed with 'at'.
2637 The instruction range is now prefixed with 'inst'.
2638 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2639 "record instruction-history" and "list" commands.
2641 * The ranges given as arguments to the 'record function-call-history' and
2642 'record instruction-history' commands are now inclusive.
2644 * The btrace record target now supports the 'record goto' command.
2645 For locations inside the execution trace, the back trace is computed
2646 based on the information stored in the execution trace.
2648 * The btrace record target supports limited reverse execution and replay.
2649 The target does not record data and therefore does not allow reading
2650 memory or registers.
2652 * The "catch syscall" command now works on s390*-linux* targets.
2654 * The "compare-sections" command is no longer specific to target
2655 remote. It now works with all targets.
2657 * All native targets are now consistently called "native".
2658 Consequently, the "target child", "target GNU", "target djgpp",
2659 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2660 commands have been replaced with "target native". The QNX/NTO port
2661 leaves the "procfs" target in place and adds a "native" target for
2662 consistency with other ports. The impact on users should be minimal
2663 as these commands previously either throwed an error, or were
2664 no-ops. The target's name is visible in the output of the following
2665 commands: "help target", "info target", "info files", "maint print
2668 * The "target native" command now connects to the native target. This
2669 can be used to launch native programs even when "set
2670 auto-connect-native-target" is set to off.
2672 * GDB now supports access to Intel MPX registers on GNU/Linux.
2674 * Support for Intel AVX-512 registers on GNU/Linux.
2675 Support displaying and modifying Intel AVX-512 registers
2676 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2678 * New remote packets
2680 qXfer:btrace:read's annex
2681 The qXfer:btrace:read packet supports a new annex 'delta' to read
2682 branch trace incrementally.
2686 ** Valid Python operations on gdb.Value objects representing
2687 structs/classes invoke the corresponding overloaded operators if
2689 ** New `Xmethods' feature in the Python API. Xmethods are
2690 additional methods or replacements for existing methods of a C++
2691 class. This feature is useful for those cases where a method
2692 defined in C++ source code could be inlined or optimized out by
2693 the compiler, making it unavailable to GDB.
2696 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2698 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2699 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2700 its alias "share", instead.
2702 * The commands "set remotebaud" and "show remotebaud" are no longer
2703 supported. Use "set serial baud" and "show serial baud" (respectively)
2708 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2709 target-async". The latter is left as a deprecated alias of the
2710 former for backward compatibility. If the target supports it,
2711 CLI background execution commands are now always possible by
2712 default, independently of whether the frontend stated a
2713 preference for asynchronous execution with "-gdb-set mi-async".
2714 Previously "-gdb-set target-async off" affected both MI execution
2715 commands and CLI execution commands.
2717 *** Changes in GDB 7.7
2719 * Improved support for process record-replay and reverse debugging on
2720 arm*-linux* targets. Support for thumb32 and syscall instruction
2721 recording has been added.
2723 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2725 * GDB now supports Fission DWP file format version 2.
2726 http://gcc.gnu.org/wiki/DebugFission
2728 * New convenience function "$_isvoid", to check whether an expression
2729 is void. A void expression is an expression where the type of the
2730 result is "void". For example, some convenience variables may be
2731 "void" when evaluated (e.g., "$_exitcode" before the execution of
2732 the program being debugged; or an undefined convenience variable).
2733 Another example, when calling a function whose return type is
2736 * The "maintenance print objfiles" command now takes an optional regexp.
2738 * The "catch syscall" command now works on arm*-linux* targets.
2740 * GDB now consistently shows "<not saved>" when printing values of
2741 registers the debug info indicates have not been saved in the frame
2742 and there's nowhere to retrieve them from
2743 (callee-saved/call-clobbered registers):
2748 (gdb) info registers rax
2751 Before, the former would print "<optimized out>", and the latter
2752 "*value not available*".
2754 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2759 ** Frame filters and frame decorators have been added.
2760 ** Temporary breakpoints are now supported.
2761 ** Line tables representation has been added.
2762 ** New attribute 'parent_type' for gdb.Field objects.
2763 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2764 ** New attribute 'name' for gdb.Type objects.
2768 Nios II ELF nios2*-*-elf
2769 Nios II GNU/Linux nios2*-*-linux
2770 Texas Instruments MSP430 msp430*-*-elf
2772 * Removed native configurations
2774 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2775 been removed. ELF variants of these configurations are kept supported.
2777 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2778 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2779 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2780 i[34567]86-*-openbsd3.[0-3]
2781 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2782 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2783 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2787 Like "catch throw", but catches a re-thrown exception.
2788 maint check-psymtabs
2789 Renamed from old "maint check-symtabs".
2791 Perform consistency checks on symtabs.
2792 maint expand-symtabs
2793 Expand symtabs matching an optional regexp.
2796 Display the details of GDB configure-time options.
2798 maint set|show per-command
2799 maint set|show per-command space
2800 maint set|show per-command time
2801 maint set|show per-command symtab
2802 Enable display of per-command gdb resource usage.
2804 remove-symbol-file FILENAME
2805 remove-symbol-file -a ADDRESS
2806 Remove a symbol file added via add-symbol-file. The file to remove
2807 can be identified by its filename or by an address that lies within
2808 the boundaries of this symbol file in memory.
2811 info exceptions REGEXP
2812 Display the list of Ada exceptions defined in the program being
2813 debugged. If provided, only the exceptions whose names match REGEXP
2818 set debug symfile off|on
2820 Control display of debugging info regarding reading symbol files and
2821 symbol tables within those files
2823 set print raw frame-arguments
2824 show print raw frame-arguments
2825 Set/show whether to print frame arguments in raw mode,
2826 disregarding any defined pretty-printers.
2828 set remote trace-status-packet
2829 show remote trace-status-packet
2830 Set/show the use of remote protocol qTStatus packet.
2834 Control display of debugging messages related to Nios II targets.
2838 Control whether target-assisted range stepping is enabled.
2840 set startup-with-shell
2841 show startup-with-shell
2842 Specifies whether Unix child processes are started via a shell or
2847 Use the target memory cache for accesses to the code segment. This
2848 improves performance of remote debugging (particularly disassembly).
2850 * You can now use a literal value 'unlimited' for options that
2851 interpret 0 or -1 as meaning "unlimited". E.g., "set
2852 trace-buffer-size unlimited" is now an alias for "set
2853 trace-buffer-size -1" and "set height unlimited" is now an alias for
2856 * The "set debug symtab-create" debugging option of GDB has been changed to
2857 accept a verbosity level. 0 means "off", 1 provides basic debugging
2858 output, and values of 2 or greater provides more verbose output.
2860 * New command-line options
2862 Display the details of GDB configure-time options.
2864 * The command 'tsave' can now support new option '-ctf' to save trace
2865 buffer in Common Trace Format.
2867 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2870 * GDB now implements the C++ 'typeid' operator.
2872 * The new convenience variable $_exception holds the exception being
2873 thrown or caught at an exception-related catchpoint.
2875 * The exception-related catchpoints, like "catch throw", now accept a
2876 regular expression which can be used to filter exceptions by type.
2878 * The new convenience variable $_exitsignal is automatically set to
2879 the terminating signal number when the program being debugged dies
2880 due to an uncaught signal.
2884 ** All MI commands now accept an optional "--language" option.
2885 Support for this feature can be verified by using the "-list-features"
2886 command, which should contain "language-option".
2888 ** The new command -info-gdb-mi-command allows the user to determine
2889 whether a GDB/MI command is supported or not.
2891 ** The "^error" result record returned when trying to execute an undefined
2892 GDB/MI command now provides a variable named "code" whose content is the
2893 "undefined-command" error code. Support for this feature can be verified
2894 by using the "-list-features" command, which should contain
2895 "undefined-command-error-code".
2897 ** The -trace-save MI command can optionally save trace buffer in Common
2900 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2902 ** The command -data-list-register-values now accepts an optional
2903 "--skip-unavailable" option. When used, only the available registers
2906 ** The new command -trace-frame-collected dumps collected variables,
2907 computed expressions, tvars, memory and registers in a traceframe.
2909 ** The commands -stack-list-locals, -stack-list-arguments and
2910 -stack-list-variables now accept an option "--skip-unavailable".
2911 When used, only the available locals or arguments are displayed.
2913 ** The -exec-run command now accepts an optional "--start" option.
2914 When used, the command follows the same semantics as the "start"
2915 command, stopping the program's execution at the start of its
2916 main subprogram. Support for this feature can be verified using
2917 the "-list-features" command, which should contain
2918 "exec-run-start-option".
2920 ** The new commands -catch-assert and -catch-exceptions insert
2921 catchpoints stopping the program when Ada exceptions are raised.
2923 ** The new command -info-ada-exceptions provides the equivalent of
2924 the new "info exceptions" command.
2926 * New system-wide configuration scripts
2927 A GDB installation now provides scripts suitable for use as system-wide
2928 configuration scripts for the following systems:
2932 * GDB now supports target-assigned range stepping with remote targets.
2933 This improves the performance of stepping source lines by reducing
2934 the number of control packets from/to GDB. See "New remote packets"
2937 * GDB now understands the element 'tvar' in the XML traceframe info.
2938 It has the id of the collected trace state variables.
2940 * On S/390 targets that provide the transactional-execution feature,
2941 the program interruption transaction diagnostic block (TDB) is now
2942 represented as a number of additional "registers" in GDB.
2944 * New remote packets
2948 The vCont packet supports a new 'r' action, that tells the remote
2949 stub to step through an address range itself, without GDB
2950 involvemement at each single-step.
2952 qXfer:libraries-svr4:read's annex
2953 The previously unused annex of the qXfer:libraries-svr4:read packet
2954 is now used to support passing an argument list. The remote stub
2955 reports support for this argument list to GDB's qSupported query.
2956 The defined arguments are "start" and "prev", used to reduce work
2957 necessary for library list updating, resulting in significant
2960 * New features in the GDB remote stub, GDBserver
2962 ** GDBserver now supports target-assisted range stepping. Currently
2963 enabled on x86/x86_64 GNU/Linux targets.
2965 ** GDBserver now adds element 'tvar' in the XML in the reply to
2966 'qXfer:traceframe-info:read'. It has the id of the collected
2967 trace state variables.
2969 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
2972 * New 'z' formatter for printing and examining memory, this displays the
2973 value as hexadecimal zero padded on the left to the size of the type.
2975 * GDB can now use Windows x64 unwinding data.
2977 * The "set remotebaud" command has been replaced by "set serial baud".
2978 Similarly, "show remotebaud" has been replaced by "show serial baud".
2979 The "set remotebaud" and "show remotebaud" commands are still available
2980 to provide backward compatibility with older versions of GDB.
2982 *** Changes in GDB 7.6
2984 * Target record has been renamed to record-full.
2985 Record/replay is now enabled with the "record full" command.
2986 This also affects settings that are associated with full record/replay
2987 that have been moved from "set/show record" to "set/show record full":
2989 set|show record full insn-number-max
2990 set|show record full stop-at-limit
2991 set|show record full memory-query
2993 * A new record target "record-btrace" has been added. The new target
2994 uses hardware support to record the control-flow of a process. It
2995 does not support replaying the execution, but it implements the
2996 below new commands for investigating the recorded execution log.
2997 This new recording method can be enabled using:
3001 The "record-btrace" target is only available on Intel Atom processors
3002 and requires a Linux kernel 2.6.32 or later.
3004 * Two new commands have been added for record/replay to give information
3005 about the recorded execution without having to replay the execution.
3006 The commands are only supported by "record btrace".
3008 record instruction-history prints the execution history at
3009 instruction granularity
3011 record function-call-history prints the execution history at
3012 function granularity
3014 * New native configurations
3016 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3017 FreeBSD/powerpc powerpc*-*-freebsd
3018 x86_64/Cygwin x86_64-*-cygwin*
3019 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3023 ARM AArch64 aarch64*-*-elf
3024 ARM AArch64 GNU/Linux aarch64*-*-linux
3025 Lynx 178 PowerPC powerpc-*-lynx*178
3026 x86_64/Cygwin x86_64-*-cygwin*
3027 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3029 * If the configured location of system.gdbinit file (as given by the
3030 --with-system-gdbinit option at configure time) is in the
3031 data-directory (as specified by --with-gdb-datadir at configure
3032 time) or in one of its subdirectories, then GDB will look for the
3033 system-wide init file in the directory specified by the
3034 --data-directory command-line option.
3036 * New command line options:
3038 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3039 other initialization files, unlike -nx which disables all of them.
3041 * Removed command line options
3043 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3046 * The 'ptype' and 'whatis' commands now accept an argument to control
3049 * 'info proc' now works on some core files.
3053 ** Vectors can be created with gdb.Type.vector.
3055 ** Python's atexit.register now works in GDB.
3057 ** Types can be pretty-printed via a Python API.
3059 ** Python 3 is now supported (in addition to Python 2.4 or later)
3061 ** New class gdb.Architecture exposes GDB's internal representation
3062 of architecture in the Python API.
3064 ** New method Frame.architecture returns the gdb.Architecture object
3065 corresponding to the frame's architecture.
3067 * New Python-based convenience functions:
3069 ** $_memeq(buf1, buf2, length)
3070 ** $_streq(str1, str2)
3072 ** $_regex(str, regex)
3074 * The 'cd' command now defaults to using '~' (the home directory) if not
3077 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3078 default for GCC since November 2000.
3080 * The command 'forward-search' can now be abbreviated as 'fo'.
3082 * The command 'info tracepoints' can now display 'installed on target'
3083 or 'not installed on target' for each non-pending location of tracepoint.
3085 * New configure options
3087 --enable-libmcheck/--disable-libmcheck
3088 By default, development versions are built with -lmcheck on hosts
3089 that support it, in order to help track memory corruption issues.
3090 Release versions, on the other hand, are built without -lmcheck
3091 by default. The --enable-libmcheck/--disable-libmcheck configure
3092 options allow the user to override that default.
3093 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3094 This configure option allows the user to build GDB with
3095 libbabeltrace using which GDB can read Common Trace Format data.
3097 * New commands (for set/show, see "New options" below)
3100 Catch signals. This is similar to "handle", but allows commands and
3101 conditions to be attached.
3104 List the BFDs known to GDB.
3106 python-interactive [command]
3108 Start a Python interactive prompt, or evaluate the optional command
3109 and print the result of expressions.
3112 "py" is a new alias for "python".
3114 enable type-printer [name]...
3115 disable type-printer [name]...
3116 Enable or disable type printers.
3120 ** For the Renesas Super-H architecture, the "regs" command has been removed
3121 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3126 set print type methods (on|off)
3127 show print type methods
3128 Control whether method declarations are displayed by "ptype".
3129 The default is to show them.
3131 set print type typedefs (on|off)
3132 show print type typedefs
3133 Control whether typedef definitions are displayed by "ptype".
3134 The default is to show them.
3136 set filename-display basename|relative|absolute
3137 show filename-display
3138 Control the way in which filenames is displayed.
3139 The default is "relative", which preserves previous behavior.
3141 set trace-buffer-size
3142 show trace-buffer-size
3143 Request target to change the size of trace buffer.
3145 set remote trace-buffer-size-packet auto|on|off
3146 show remote trace-buffer-size-packet
3147 Control the use of the remote protocol `QTBuffer:size' packet.
3151 Control display of debugging messages related to ARM AArch64.
3154 set debug coff-pe-read
3155 show debug coff-pe-read
3156 Control display of debugging messages related to reading of COFF/PE
3161 Control display of debugging messages related to Mach-O symbols
3164 set debug notification
3165 show debug notification
3166 Control display of debugging info for async remote notification.
3170 ** Command parameter changes are now notified using new async record
3171 "=cmd-param-changed".
3172 ** Trace frame changes caused by command "tfind" are now notified using
3173 new async record "=traceframe-changed".
3174 ** The creation, deletion and modification of trace state variables
3175 are now notified using new async records "=tsv-created",
3176 "=tsv-deleted" and "=tsv-modified".
3177 ** The start and stop of process record are now notified using new
3178 async record "=record-started" and "=record-stopped".
3179 ** Memory changes are now notified using new async record
3181 ** The data-disassemble command response will include a "fullname" field
3182 containing the absolute file name when source has been requested.
3183 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3184 command, to allow pattern filling of memory areas.
3185 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3186 library load/unload events.
3187 ** The response to breakpoint commands and breakpoint async records
3188 includes an "installed" field containing a boolean state about each
3189 non-pending tracepoint location is whether installed on target or not.
3190 ** Output of the "-trace-status" command includes a "trace-file" field
3191 containing the name of the trace file being examined. This field is
3192 optional, and only present when examining a trace file.
3193 ** The "fullname" field is now always present along with the "file" field,
3194 even if the file cannot be found by GDB.
3196 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3197 You must have the LZMA library available when configuring GDB for this
3198 feature to be enabled. For more information, see:
3199 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3201 * New remote packets
3204 Set the size of trace buffer. The remote stub reports support for this
3205 packet to gdb's qSupported query.
3208 Enable Branch Trace Store (BTS)-based branch tracing for the current
3209 thread. The remote stub reports support for this packet to gdb's
3213 Disable branch tracing for the current thread. The remote stub reports
3214 support for this packet to gdb's qSupported query.
3217 Read the traced branches for the current thread. The remote stub
3218 reports support for this packet to gdb's qSupported query.
3220 *** Changes in GDB 7.5
3222 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3223 for more x32 ABI info.
3225 * GDB now supports access to MIPS DSP registers on Linux targets.
3227 * GDB now supports debugging microMIPS binaries.
3229 * The "info os" command on GNU/Linux can now display information on
3230 several new classes of objects managed by the operating system:
3231 "info os procgroups" lists process groups
3232 "info os files" lists file descriptors
3233 "info os sockets" lists internet-domain sockets
3234 "info os shm" lists shared-memory regions
3235 "info os semaphores" lists semaphores
3236 "info os msg" lists message queues
3237 "info os modules" lists loaded kernel modules
3239 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3240 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3241 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3242 options and inspect the probe arguments using the new $_probe_arg family
3243 of convenience variables. You can obtain more information about SystemTap
3244 in <http://sourceware.org/systemtap/>.
3246 * GDB now supports reversible debugging on ARM, it allows you to
3247 debug basic ARM and THUMB instructions, and provides
3248 record/replay support.
3250 * The option "symbol-reloading" has been deleted as it is no longer used.
3254 ** GDB commands implemented in Python can now be put in command class
3257 ** The "maint set python print-stack on|off" is now deleted.
3259 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3260 apply "flag enum"-style pretty-printing to any enum.
3262 ** gdb.lookup_symbol can now work when there is no current frame.
3264 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3265 the source at which the symbol was defined.
3267 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3268 method 'value'. The former indicates whether the symbol needs a
3269 frame in order to compute its value, and the latter computes the
3272 ** A new method 'referenced_value' on gdb.Value objects which can
3273 dereference pointer as well as C++ reference values.
3275 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3276 which return the global and static blocks (as gdb.Block objects),
3277 of the underlying symbol table, respectively.
3279 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3280 object associated with a PC value.
3282 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3283 of the address range occupied by code for the current source line.
3285 * Go language support.
3286 GDB now supports debugging programs written in the Go programming
3289 * GDBserver now supports stdio connections.
3290 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3292 * The binary "gdbtui" can no longer be built or installed.
3293 Use "gdb -tui" instead.
3295 * GDB will now print "flag" enums specially. A flag enum is one where
3296 all the enumerator values have no bits in common when pairwise
3297 "and"ed. When printing a value whose type is a flag enum, GDB will
3298 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3299 (gdb) print (enum E) 3
3302 * The filename part of a linespec will now match trailing components
3303 of a source file name. For example, "break gcc/expr.c:1000" will
3304 now set a breakpoint in build/gcc/expr.c, but not
3305 build/libcpp/expr.c.
3307 * The "info proc" and "generate-core-file" commands will now also
3308 work on remote targets connected to GDBserver on Linux.
3310 * The command "info catch" has been removed. It has been disabled
3311 since December 2007.
3313 * The "catch exception" and "catch assert" commands now accept
3314 a condition at the end of the command, much like the "break"
3315 command does. For instance:
3317 (gdb) catch exception Constraint_Error if Barrier = True
3319 Previously, it was possible to add a condition to such catchpoints,
3320 but it had to be done as a second step, after the catchpoint had been
3321 created, using the "condition" command.
3323 * The "info static-tracepoint-marker" command will now also work on
3324 native Linux targets with in-process agent.
3326 * GDB can now set breakpoints on inlined functions.
3328 * The .gdb_index section has been updated to include symbols for
3329 inlined functions. GDB will ignore older .gdb_index sections by
3330 default, which could cause symbol files to be loaded more slowly
3331 until their .gdb_index sections can be recreated. The new command
3332 "set use-deprecated-index-sections on" will cause GDB to use any older
3333 .gdb_index sections it finds. This will restore performance, but the
3334 ability to set breakpoints on inlined functions will be lost in symbol
3335 files with older .gdb_index sections.
3337 The .gdb_index section has also been updated to record more information
3338 about each symbol. This speeds up the "info variables", "info functions"
3339 and "info types" commands when used with programs having the .gdb_index
3340 section, as well as speeding up debugging with shared libraries using
3341 the .gdb_index section.
3343 * Ada support for GDB/MI Variable Objects has been added.
3345 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3350 ** New command -info-os is the MI equivalent of "info os".
3352 ** Output logs ("set logging" and related) now include MI output.
3356 ** "set use-deprecated-index-sections on|off"
3357 "show use-deprecated-index-sections on|off"
3358 Controls the use of deprecated .gdb_index sections.
3360 ** "catch load" and "catch unload" can be used to stop when a shared
3361 library is loaded or unloaded, respectively.
3363 ** "enable count" can be used to auto-disable a breakpoint after
3366 ** "info vtbl" can be used to show the virtual method tables for
3367 C++ and Java objects.
3369 ** "explore" and its sub commands "explore value" and "explore type"
3370 can be used to recursively explore values and types of
3371 expressions. These commands are available only if GDB is
3372 configured with '--with-python'.
3374 ** "info auto-load" shows status of all kinds of auto-loaded files,
3375 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3376 sequences of commands files, "info auto-load python-scripts"
3377 shows status of auto-loading Python script files,
3378 "info auto-load local-gdbinit" shows status of loading init file
3379 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3380 status of inferior specific thread debugging shared library loading.
3382 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3383 and "show auto-load-scripts" commands have been deprecated, use their
3384 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3385 and "show auto-load python-scripts" counterparts instead.
3387 ** "dprintf location,format,args..." creates a dynamic printf, which
3388 is basically a breakpoint that does a printf and immediately
3389 resumes your program's execution, so it is like a printf that you
3390 can insert dynamically at runtime instead of at compiletime.
3392 ** "set print symbol"
3394 Controls whether GDB attempts to display the symbol, if any,
3395 corresponding to addresses it prints. This defaults to "on", but
3396 you can set it to "off" to restore GDB's previous behavior.
3398 * Deprecated commands
3400 ** For the Renesas Super-H architecture, the "regs" command has been
3401 deprecated, and "info all-registers" should be used instead.
3405 Renesas RL78 rl78-*-elf
3406 HP OpenVMS ia64 ia64-hp-openvms*
3408 * GDBserver supports evaluation of breakpoint conditions. When
3409 support is advertised by GDBserver, GDB may be told to send the
3410 breakpoint conditions in bytecode form to GDBserver. GDBserver
3411 will only report the breakpoint trigger to GDB when its condition
3416 set mips compression
3417 show mips compression
3418 Select the compressed ISA encoding used in functions that have no symbol
3419 information available. The encoding can be set to either of:
3422 and is updated automatically from ELF file flags if available.
3424 set breakpoint condition-evaluation
3425 show breakpoint condition-evaluation
3426 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3427 GDBserver ("target"). Default option "auto" chooses the most efficient
3429 This option can improve debugger efficiency depending on the speed of the
3433 Disable auto-loading globally.
3436 Show auto-loading setting of all kinds of auto-loaded files.
3438 set auto-load gdb-scripts on|off
3439 show auto-load gdb-scripts
3440 Control auto-loading of GDB canned sequences of commands files.
3442 set auto-load python-scripts on|off
3443 show auto-load python-scripts
3444 Control auto-loading of Python script files.
3446 set auto-load local-gdbinit on|off
3447 show auto-load local-gdbinit
3448 Control loading of init file (.gdbinit) from current directory.
3450 set auto-load libthread-db on|off
3451 show auto-load libthread-db
3452 Control auto-loading of inferior specific thread debugging shared library.
3454 set auto-load scripts-directory <dir1>[:<dir2>...]
3455 show auto-load scripts-directory
3456 Set a list of directories from which to load auto-loaded scripts.
3457 Automatically loaded Python scripts and GDB scripts are located in one
3458 of the directories listed by this option.
3459 The delimiter (':' above) may differ according to the host platform.
3461 set auto-load safe-path <dir1>[:<dir2>...]
3462 show auto-load safe-path
3463 Set a list of directories from which it is safe to auto-load files.
3464 The delimiter (':' above) may differ according to the host platform.
3466 set debug auto-load on|off
3467 show debug auto-load
3468 Control display of debugging info for auto-loading the files above.
3470 set dprintf-style gdb|call|agent
3472 Control the way in which a dynamic printf is performed; "gdb"
3473 requests a GDB printf command, while "call" causes dprintf to call a
3474 function in the inferior. "agent" requests that the target agent
3475 (such as GDBserver) do the printing.
3477 set dprintf-function <expr>
3478 show dprintf-function
3479 set dprintf-channel <expr>
3480 show dprintf-channel
3481 Set the function and optional first argument to the call when using
3482 the "call" style of dynamic printf.
3484 set disconnected-dprintf on|off
3485 show disconnected-dprintf
3486 Control whether agent-style dynamic printfs continue to be in effect
3487 after GDB disconnects.
3489 * New configure options
3491 --with-auto-load-dir
3492 Configure default value for the 'set auto-load scripts-directory'
3493 setting above. It defaults to '$debugdir:$datadir/auto-load',
3494 $debugdir representing global debugging info directories (available
3495 via 'show debug-file-directory') and $datadir representing GDB's data
3496 directory (available via 'show data-directory').
3498 --with-auto-load-safe-path
3499 Configure default value for the 'set auto-load safe-path' setting
3500 above. It defaults to the --with-auto-load-dir setting.
3502 --without-auto-load-safe-path
3503 Set 'set auto-load safe-path' to '/', effectively disabling this
3506 * New remote packets
3508 z0/z1 conditional breakpoints extension
3510 The z0/z1 breakpoint insertion packets have been extended to carry
3511 a list of conditional expressions over to the remote stub depending on the
3512 condition evaluation mode. The use of this extension can be controlled
3513 via the "set remote conditional-breakpoints-packet" command.
3517 Specify the signals which the remote stub may pass to the debugged
3518 program without GDB involvement.
3520 * New command line options
3522 --init-command=FILE, -ix Like --command, -x but execute it
3523 before loading inferior.
3524 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3525 execute it before loading inferior.
3527 *** Changes in GDB 7.4
3529 * GDB now handles ambiguous linespecs more consistently; the existing
3530 FILE:LINE support has been expanded to other types of linespecs. A
3531 breakpoint will now be set on all matching locations in all
3532 inferiors, and locations will be added or removed according to
3535 * GDB now allows you to skip uninteresting functions and files when
3536 stepping with the "skip function" and "skip file" commands.
3538 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3539 and "show remote hardware-watchpoint-length-limit". These allows to
3540 set or show the maximum length limit (in bytes) of a remote
3541 target hardware watchpoint.
3543 This allows e.g. to use "unlimited" hardware watchpoints with the
3544 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3545 watchpoints are slower than real hardware watchpoints but are
3546 significantly faster than gdb software watchpoints.
3550 ** The register_pretty_printer function in module gdb.printing now takes
3551 an optional `replace' argument. If True, the new printer replaces any
3554 ** The "maint set python print-stack on|off" command has been
3555 deprecated and will be deleted in GDB 7.5.
3556 A new command: "set python print-stack none|full|message" has
3557 replaced it. Additionally, the default for "print-stack" is
3558 now "message", which just prints the error message without
3561 ** A prompt substitution hook (prompt_hook) is now available to the
3564 ** A new Python module, gdb.prompt has been added to the GDB Python
3565 modules library. This module provides functionality for
3566 escape sequences in prompts (used by set/show
3567 extended-prompt). These escape sequences are replaced by their
3568 corresponding value.
3570 ** Python commands and convenience-functions located in
3571 'data-directory'/python/gdb/command and
3572 'data-directory'/python/gdb/function are now automatically loaded
3575 ** Blocks now provide four new attributes. global_block and
3576 static_block will return the global and static blocks
3577 respectively. is_static and is_global are boolean attributes
3578 that indicate if the block is one of those two types.
3580 ** Symbols now provide the "type" attribute, the type of the symbol.
3582 ** The "gdb.breakpoint" function has been deprecated in favor of
3585 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3586 of a function. This class is based on the "finish" command
3587 available in the CLI.
3589 ** Type objects for struct and union types now allow access to
3590 the fields using standard Python dictionary (mapping) methods.
3591 For example, "some_type['myfield']" now works, as does
3592 "some_type.items()".
3594 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3597 ** A new function, "deep_items" has been added to the gdb.types
3598 module in the GDB Python modules library. This function returns
3599 an iterator over the fields of a struct or union type. Unlike
3600 the standard Python "iteritems" method, it will recursively traverse
3601 any anonymous fields.
3605 ** "*stopped" events can report several new "reason"s, such as
3608 ** Breakpoint changes are now notified using new async records, like
3609 "=breakpoint-modified".
3611 ** New command -ada-task-info.
3613 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3614 $sdir specifies the default system locations of shared libraries.
3615 $pdir specifies the directory where the libpthread used by the application
3618 GDB no longer looks in $sdir and $pdir after it has searched the directories
3619 mentioned in libthread-db-search-path. If you want to search those
3620 directories, they must be specified in libthread-db-search-path.
3621 The default value of libthread-db-search-path on GNU/Linux and Solaris
3622 systems is now "$sdir:$pdir".
3624 $pdir is not supported by gdbserver, it is currently ignored.
3625 $sdir is supported by gdbserver.
3627 * New configure option --with-iconv-bin.
3628 When using the internationalization support like the one in the GNU C
3629 library, GDB will invoke the "iconv" program to get a list of supported
3630 character sets. If this program lives in a non-standard location, one can
3631 use this option to specify where to find it.
3633 * When natively debugging programs on PowerPC BookE processors running
3634 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3635 watchpoints, which specify a mask in addition to an address to watch.
3636 The mask specifies that some bits of an address (the bits which are
3637 reset in the mask) should be ignored when matching the address accessed
3638 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3639 section in the user manual for more details.
3641 * The new option --once causes GDBserver to stop listening for connections once
3642 the first connection is made. The listening port used by GDBserver will
3643 become available after that.
3645 * New commands "info macros" and "alias" have been added.
3647 * New function parameters suffix @entry specifies value of function parameter
3648 at the time the function got called. Entry values are available only since
3654 "!" is now an alias of the "shell" command.
3655 Note that no space is needed between "!" and SHELL COMMAND.
3659 watch EXPRESSION mask MASK_VALUE
3660 The watch command now supports the mask argument which allows creation
3661 of masked watchpoints, if the current architecture supports this feature.
3663 info auto-load-scripts [REGEXP]
3664 This command was formerly named "maintenance print section-scripts".
3665 It is now generally useful and is no longer a maintenance-only command.
3667 info macro [-all] [--] MACRO
3668 The info macro command has new options `-all' and `--'. The first for
3669 printing all definitions of a macro. The second for explicitly specifying
3670 the end of arguments and the beginning of the macro name in case the macro
3671 name starts with a hyphen.
3673 collect[/s] EXPRESSIONS
3674 The tracepoint collect command now takes an optional modifier "/s"
3675 that directs it to dereference pointer-to-character types and
3676 collect the bytes of memory up to a zero byte. The behavior is
3677 similar to what you see when you use the regular print command on a
3678 string. An optional integer following the "/s" sets a bound on the
3679 number of bytes that will be collected.
3682 The trace start command now interprets any supplied arguments as a
3683 note to be recorded with the trace run, with an effect similar to
3684 setting the variable trace-notes.
3687 The trace stop command now interprets any arguments as a note to be
3688 mentioned along with the tstatus report that the trace was stopped
3689 with a command. The effect is similar to setting the variable
3692 * Tracepoints can now be enabled and disabled at any time after a trace
3693 experiment has been started using the standard "enable" and "disable"
3694 commands. It is now possible to start a trace experiment with no enabled
3695 tracepoints; GDB will display a warning, but will allow the experiment to
3696 begin, assuming that tracepoints will be enabled as needed while the trace
3699 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3700 locations with 4-byte instructions, when they were previously
3701 limited to locations with instructions of 5 bytes or longer.
3705 set debug dwarf2-read
3706 show debug dwarf2-read
3707 Turns on or off display of debugging messages related to reading
3708 DWARF debug info. The default is off.
3710 set debug symtab-create
3711 show debug symtab-create
3712 Turns on or off display of debugging messages related to symbol table
3713 creation. The default is off.
3716 show extended-prompt
3717 Set the GDB prompt, and allow escape sequences to be inserted to
3718 display miscellaneous information (see 'help set extended-prompt'
3719 for the list of sequences). This prompt (and any information
3720 accessed through the escape sequences) is updated every time the
3721 prompt is displayed.
3723 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3724 show print entry-values
3725 Set printing of frame argument values at function entry. In some cases
3726 GDB can determine the value of function argument which was passed by the
3727 function caller, even if the value was modified inside the called function.
3729 set debug entry-values
3730 show debug entry-values
3731 Control display of debugging info for determining frame argument values at
3732 function entry and virtual tail call frames.
3734 set basenames-may-differ
3735 show basenames-may-differ
3736 Set whether a source file may have multiple base names.
3737 (A "base name" is the name of a file with the directory part removed.
3738 Example: The base name of "/home/user/hello.c" is "hello.c".)
3739 If set, GDB will canonicalize file names (e.g., expand symlinks)
3740 before comparing them. Canonicalization is an expensive operation,
3741 but it allows the same file be known by more than one base name.
3742 If not set (the default), all source files are assumed to have just
3743 one base name, and gdb will do file name comparisons more efficiently.
3749 Set a user name and notes for the current and any future trace runs.
3750 This is useful for long-running and/or disconnected traces, to
3751 inform others (or yourself) as to who is running the trace, supply
3752 contact information, or otherwise explain what is going on.
3754 set trace-stop-notes
3755 show trace-stop-notes
3756 Set a note attached to the trace run, that is displayed when the
3757 trace has been stopped by a tstop command. This is useful for
3758 instance as an explanation, if you are stopping a trace run that was
3759 started by someone else.
3761 * New remote packets
3765 Dynamically enable a tracepoint in a started trace experiment.
3769 Dynamically disable a tracepoint in a started trace experiment.
3773 Set the user and notes of the trace run.
3777 Query the current status of a tracepoint.
3781 Query the minimum length of instruction at which a fast tracepoint may
3784 * Dcache size (number of lines) and line-size are now runtime-configurable
3785 via "set dcache line" and "set dcache line-size" commands.
3789 Texas Instruments TMS320C6x tic6x-*-*
3793 Renesas RL78 rl78-*-elf
3795 *** Changes in GDB 7.3.1
3797 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3799 *** Changes in GDB 7.3
3801 * GDB has a new command: "thread find [REGEXP]".
3802 It finds the thread id whose name, target id, or thread extra info
3803 matches the given regular expression.
3805 * The "catch syscall" command now works on mips*-linux* targets.
3807 * The -data-disassemble MI command now supports modes 2 and 3 for
3808 dumping the instruction opcodes.
3810 * New command line options
3812 -data-directory DIR Specify DIR as the "data-directory".
3813 This is mostly for testing purposes.
3815 * The "maint set python auto-load on|off" command has been renamed to
3816 "set auto-load-scripts on|off".
3818 * GDB has a new command: "set directories".
3819 It is like the "dir" command except that it replaces the
3820 source path list instead of augmenting it.
3822 * GDB now understands thread names.
3824 On GNU/Linux, "info threads" will display the thread name as set by
3825 prctl or pthread_setname_np.
3827 There is also a new command, "thread name", which can be used to
3828 assign a name internally for GDB to display.
3831 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3832 has been integrated into GDB.
3836 ** The function gdb.Write now accepts an optional keyword 'stream'.
3837 This keyword, when provided, will direct the output to either
3838 stdout, stderr, or GDB's logging output.
3840 ** Parameters can now be be sub-classed in Python, and in particular
3841 you may implement the get_set_doc and get_show_doc functions.
3842 This improves how Parameter set/show documentation is processed
3843 and allows for more dynamic content.
3845 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3846 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3847 have an is_valid method.
3849 ** Breakpoints can now be sub-classed in Python, and in particular
3850 you may implement a 'stop' function that is executed each time
3851 the inferior reaches that breakpoint.
3853 ** New function gdb.lookup_global_symbol looks up a global symbol.
3855 ** GDB values in Python are now callable if the value represents a
3856 function. For example, if 'some_value' represents a function that
3857 takes two integer parameters and returns a value, you can call
3858 that function like so:
3860 result = some_value (10,20)
3862 ** Module gdb.types has been added.
3863 It contains a collection of utilities for working with gdb.Types objects:
3864 get_basic_type, has_field, make_enum_dict.
3866 ** Module gdb.printing has been added.
3867 It contains utilities for writing and registering pretty-printers.
3868 New classes: PrettyPrinter, SubPrettyPrinter,
3869 RegexpCollectionPrettyPrinter.
3870 New function: register_pretty_printer.
3872 ** New commands "info pretty-printers", "enable pretty-printer" and
3873 "disable pretty-printer" have been added.
3875 ** gdb.parameter("directories") is now available.
3877 ** New function gdb.newest_frame returns the newest frame in the
3880 ** The gdb.InferiorThread class has a new "name" attribute. This
3881 holds the thread's name.
3883 ** Python Support for Inferior events.
3884 Python scripts can add observers to be notified of events
3885 occurring in the process being debugged.
3886 The following events are currently supported:
3887 - gdb.events.cont Continue event.
3888 - gdb.events.exited Inferior exited event.
3889 - gdb.events.stop Signal received, and Breakpoint hit events.
3893 ** GDB now puts template parameters in scope when debugging in an
3894 instantiation. For example, if you have:
3896 template<int X> int func (void) { return X; }
3898 then if you step into func<5>, "print X" will show "5". This
3899 feature requires proper debuginfo support from the compiler; it
3900 was added to GCC 4.5.
3902 ** The motion commands "next", "finish", "until", and "advance" now
3903 work better when exceptions are thrown. In particular, GDB will
3904 no longer lose control of the inferior; instead, the GDB will
3905 stop the inferior at the point at which the exception is caught.
3906 This functionality requires a change in the exception handling
3907 code that was introduced in GCC 4.5.
3909 * GDB now follows GCC's rules on accessing volatile objects when
3910 reading or writing target state during expression evaluation.
3911 One notable difference to prior behavior is that "print x = 0"
3912 no longer generates a read of x; the value of the assignment is
3913 now always taken directly from the value being assigned.
3915 * GDB now has some support for using labels in the program's source in
3916 linespecs. For instance, you can use "advance label" to continue
3917 execution to a label.
3919 * GDB now has support for reading and writing a new .gdb_index
3920 section. This section holds a fast index of DWARF debugging
3921 information and can be used to greatly speed up GDB startup and
3922 operation. See the documentation for `save gdb-index' for details.
3924 * The "watch" command now accepts an optional "-location" argument.
3925 When used, this causes GDB to watch the memory referred to by the
3926 expression. Such a watchpoint is never deleted due to it going out
3929 * GDB now supports thread debugging of core dumps on GNU/Linux.
3931 GDB now activates thread debugging using the libthread_db library
3932 when debugging GNU/Linux core dumps, similarly to when debugging
3933 live processes. As a result, when debugging a core dump file, GDB
3934 is now able to display pthread_t ids of threads. For example, "info
3935 threads" shows the same output as when debugging the process when it
3936 was live. In earlier releases, you'd see something like this:
3939 * 1 LWP 6780 main () at main.c:10
3941 While now you see this:
3944 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3946 It is also now possible to inspect TLS variables when debugging core
3949 When debugging a core dump generated on a machine other than the one
3950 used to run GDB, you may need to point GDB at the correct
3951 libthread_db library with the "set libthread-db-search-path"
3952 command. See the user manual for more details on this command.
3954 * When natively debugging programs on PowerPC BookE processors running
3955 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3956 which stop execution of the inferior whenever it executes an instruction
3957 at any address within the specified range. See the "PowerPC Embedded"
3958 section in the user manual for more details.
3960 * New features in the GDB remote stub, GDBserver
3962 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3963 and i686 LynxOS (version 5.x).
3965 ** GDBserver is now supported on Blackfin Linux.
3967 * New native configurations
3969 ia64 HP-UX ia64-*-hpux*
3973 Analog Devices, Inc. Blackfin Processor bfin-*
3975 * Ada task switching is now supported on sparc-elf targets when
3976 debugging a program using the Ravenscar Profile. For more information,
3977 see the "Tasking Support when using the Ravenscar Profile" section
3978 in the GDB user manual.
3980 * Guile support was removed.
3982 * New features in the GNU simulator
3984 ** The --map-info flag lists all known core mappings.
3986 ** CFI flashes may be simulated via the "cfi" device.
3988 *** Changes in GDB 7.2
3990 * Shared library support for remote targets by default
3992 When GDB is configured for a generic, non-OS specific target, like
3993 for example, --target=arm-eabi or one of the many *-*-elf targets,
3994 GDB now queries remote stubs for loaded shared libraries using the
3995 `qXfer:libraries:read' packet. Previously, shared library support
3996 was always disabled for such configurations.
4000 ** Argument Dependent Lookup (ADL)
4002 In C++ ADL lookup directs function search to the namespaces of its
4003 arguments even if the namespace has not been imported.
4013 Here the compiler will search for `foo' in the namespace of 'b'
4014 and find A::foo. GDB now supports this. This construct is commonly
4015 used in the Standard Template Library for operators.
4017 ** Improved User Defined Operator Support
4019 In addition to member operators, GDB now supports lookup of operators
4020 defined in a namespace and imported with a `using' directive, operators
4021 defined in the global scope, operators imported implicitly from an
4022 anonymous namespace, and the ADL operators mentioned in the previous
4024 GDB now also supports proper overload resolution for all the previously
4025 mentioned flavors of operators.
4027 ** static const class members
4029 Printing of static const class members that are initialized in the
4030 class definition has been fixed.
4032 * Windows Thread Information Block access.
4034 On Windows targets, GDB now supports displaying the Windows Thread
4035 Information Block (TIB) structure. This structure is visible either
4036 by using the new command `info w32 thread-information-block' or, by
4037 dereferencing the new convenience variable named `$_tlb', a
4038 thread-specific pointer to the TIB. This feature is also supported
4039 when remote debugging using GDBserver.
4041 * Static tracepoints
4043 Static tracepoints are calls in the user program into a tracing
4044 library. One such library is a port of the LTTng kernel tracer to
4045 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4046 When debugging with GDBserver, GDB now supports combining the GDB
4047 tracepoint machinery with such libraries. For example: the user can
4048 use GDB to probe a static tracepoint marker (a call from the user
4049 program into the tracing library) with the new "strace" command (see
4050 "New commands" below). This creates a "static tracepoint" in the
4051 breakpoint list, that can be manipulated with the same feature set
4052 as fast and regular tracepoints. E.g., collect registers, local and
4053 global variables, collect trace state variables, and define
4054 tracepoint conditions. In addition, the user can collect extra
4055 static tracepoint marker specific data, by collecting the new
4056 $_sdata internal variable. When analyzing the trace buffer, you can
4057 inspect $_sdata like any other variable available to GDB. For more
4058 information, see the "Tracepoints" chapter in GDB user manual. New
4059 remote packets have been defined to support static tracepoints, see
4060 the "New remote packets" section below.
4062 * Better reconstruction of tracepoints after disconnected tracing
4064 GDB will attempt to download the original source form of tracepoint
4065 definitions when starting a trace run, and then will upload these
4066 upon reconnection to the target, resulting in a more accurate
4067 reconstruction of the tracepoints that are in use on the target.
4071 You can now exercise direct control over the ways that GDB can
4072 affect your program. For instance, you can disallow the setting of
4073 breakpoints, so that the program can run continuously (assuming
4074 non-stop mode). In addition, the "observer" variable is available
4075 to switch all of the different controls; in observer mode, GDB
4076 cannot affect the target's behavior at all, which is useful for
4077 tasks like diagnosing live systems in the field.
4079 * The new convenience variable $_thread holds the number of the
4082 * New remote packets
4086 Return the address of the Windows Thread Information Block of a given thread.
4090 In response to several of the tracepoint packets, the target may now
4091 also respond with a number of intermediate `qRelocInsn' request
4092 packets before the final result packet, to have GDB handle
4093 relocating an instruction to execute at a different address. This
4094 is particularly useful for stubs that support fast tracepoints. GDB
4095 reports support for this feature in the qSupported packet.
4099 List static tracepoint markers in the target program.
4103 List static tracepoint markers at a given address in the target
4106 qXfer:statictrace:read
4108 Read the static trace data collected (by a `collect $_sdata'
4109 tracepoint action). The remote stub reports support for this packet
4110 to gdb's qSupported query.
4114 Send the current settings of GDB's permission flags.
4118 Send part of the source (textual) form of a tracepoint definition,
4119 which includes location, conditional, and action list.
4121 * The source command now accepts a -s option to force searching for the
4122 script in the source search path even if the script name specifies
4125 * New features in the GDB remote stub, GDBserver
4127 - GDBserver now support tracepoints (including fast tracepoints, and
4128 static tracepoints). The feature is currently supported by the
4129 i386-linux and amd64-linux builds. See the "Tracepoints support
4130 in gdbserver" section in the manual for more information.
4132 GDBserver JIT compiles the tracepoint's conditional agent
4133 expression bytecode into native code whenever possible for low
4134 overhead dynamic tracepoints conditionals. For such tracepoints,
4135 an expression that examines program state is evaluated when the
4136 tracepoint is reached, in order to determine whether to capture
4137 trace data. If the condition is simple and false, processing the
4138 tracepoint finishes very quickly and no data is gathered.
4140 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4141 for static tracepoints support.
4143 - GDBserver now supports x86_64 Windows 64-bit debugging.
4145 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4146 it understands register description.
4148 * The --batch flag now disables pagination and queries.
4150 * X86 general purpose registers
4152 GDB now supports reading/writing byte, word and double-word x86
4153 general purpose registers directly. This means you can use, say,
4154 $ah or $ax to refer, respectively, to the byte register AH and
4155 16-bit word register AX that are actually portions of the 32-bit
4156 register EAX or 64-bit register RAX.
4158 * The `commands' command now accepts a range of breakpoints to modify.
4159 A plain `commands' following a command that creates multiple
4160 breakpoints affects all the breakpoints set by that command. This
4161 applies to breakpoints set by `rbreak', and also applies when a
4162 single `break' command creates multiple breakpoints (e.g.,
4163 breakpoints on overloaded c++ functions).
4165 * The `rbreak' command now accepts a filename specification as part of
4166 its argument, limiting the functions selected by the regex to those
4167 in the specified file.
4169 * Support for remote debugging Windows and SymbianOS shared libraries
4170 from Unix hosts has been improved. Non Windows GDB builds now can
4171 understand target reported file names that follow MS-DOS based file
4172 system semantics, such as file names that include drive letters and
4173 use the backslash character as directory separator. This makes it
4174 possible to transparently use the "set sysroot" and "set
4175 solib-search-path" on Unix hosts to point as host copies of the
4176 target's shared libraries. See the new command "set
4177 target-file-system-kind" described below, and the "Commands to
4178 specify files" section in the user manual for more information.
4182 eval template, expressions...
4183 Convert the values of one or more expressions under the control
4184 of the string template to a command line, and call it.
4186 set target-file-system-kind unix|dos-based|auto
4187 show target-file-system-kind
4188 Set or show the assumed file system kind for target reported file
4191 save breakpoints <filename>
4192 Save all current breakpoint definitions to a file suitable for use
4193 in a later debugging session. To read the saved breakpoint
4194 definitions, use the `source' command.
4196 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4199 info static-tracepoint-markers
4200 Display information about static tracepoint markers in the target.
4202 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4203 Define a static tracepoint by probing a marker at the given
4204 function, line, address, or marker ID.
4208 Enable and disable observer mode.
4210 set may-write-registers on|off
4211 set may-write-memory on|off
4212 set may-insert-breakpoints on|off
4213 set may-insert-tracepoints on|off
4214 set may-insert-fast-tracepoints on|off
4215 set may-interrupt on|off
4216 Set individual permissions for GDB effects on the target. Note that
4217 some of these settings can have undesirable or surprising
4218 consequences, particularly when changed in the middle of a session.
4219 For instance, disabling the writing of memory can prevent
4220 breakpoints from being inserted, cause single-stepping to fail, or
4221 even crash your program, if you disable after breakpoints have been
4222 inserted. However, GDB should not crash.
4224 set record memory-query on|off
4225 show record memory-query
4226 Control whether to stop the inferior if memory changes caused
4227 by an instruction cannot be recorded.
4232 The disassemble command now supports "start,+length" form of two arguments.
4236 ** GDB now provides a new directory location, called the python directory,
4237 where Python scripts written for GDB can be installed. The location
4238 of that directory is <data-directory>/python, where <data-directory>
4239 is the GDB data directory. For more details, see section `Scripting
4240 GDB using Python' in the manual.
4242 ** The GDB Python API now has access to breakpoints, symbols, symbol
4243 tables, program spaces, inferiors, threads and frame's code blocks.
4244 Additionally, GDB Parameters can now be created from the API, and
4245 manipulated via set/show in the CLI.
4247 ** New functions gdb.target_charset, gdb.target_wide_charset,
4248 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4250 ** New exception gdb.GdbError.
4252 ** Pretty-printers are now also looked up in the current program space.
4254 ** Pretty-printers can now be individually enabled and disabled.
4256 ** GDB now looks for names of Python scripts to auto-load in a
4257 special section named `.debug_gdb_scripts', in addition to looking
4258 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4260 * Tracepoint actions were unified with breakpoint commands. In particular,
4261 there are no longer differences in "info break" output for breakpoints and
4262 tracepoints and the "commands" command can be used for both tracepoints and
4263 regular breakpoints.
4267 ARM Symbian arm*-*-symbianelf*
4269 * D language support.
4270 GDB now supports debugging programs written in the D programming
4273 * GDB now supports the extended ptrace interface for PowerPC which is
4274 available since Linux kernel version 2.6.34. This automatically enables
4275 any hardware breakpoints and additional hardware watchpoints available in
4276 the processor. The old ptrace interface exposes just one hardware
4277 watchpoint and no hardware breakpoints.
4279 * GDB is now able to use the Data Value Compare (DVC) register available on
4280 embedded PowerPC processors to implement in hardware simple watchpoint
4281 conditions of the form:
4283 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4285 This works in native GDB running on Linux kernels with the extended ptrace
4286 interface mentioned above.
4288 *** Changes in GDB 7.1
4292 ** Namespace Support
4294 GDB now supports importing of namespaces in C++. This enables the
4295 user to inspect variables from imported namespaces. Support for
4296 namepace aliasing has also been added. So, if a namespace is
4297 aliased in the current scope (e.g. namepace C=A; ) the user can
4298 print variables using the alias (e.g. (gdb) print C::x).
4302 All known bugs relating to the printing of virtual base class were
4303 fixed. It is now possible to call overloaded static methods using a
4308 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4309 and reinterpret_cast<> are now handled by the C++ expression parser.
4313 Xilinx MicroBlaze microblaze-*-*
4318 Xilinx MicroBlaze microblaze
4321 * Multi-program debugging.
4323 GDB now has support for multi-program (a.k.a. multi-executable or
4324 multi-exec) debugging. This allows for debugging multiple inferiors
4325 simultaneously each running a different program under the same GDB
4326 session. See "Debugging Multiple Inferiors and Programs" in the
4327 manual for more information. This implied some user visible changes
4328 in the multi-inferior support. For example, "info inferiors" now
4329 lists inferiors that are not running yet or that have exited
4330 already. See also "New commands" and "New options" below.
4332 * New tracing features
4334 GDB's tracepoint facility now includes several new features:
4336 ** Trace state variables
4338 GDB tracepoints now include support for trace state variables, which
4339 are variables managed by the target agent during a tracing
4340 experiment. They are useful for tracepoints that trigger each
4341 other, so for instance one tracepoint can count hits in a variable,
4342 and then a second tracepoint has a condition that is true when the
4343 count reaches a particular value. Trace state variables share the
4344 $-syntax of GDB convenience variables, and can appear in both
4345 tracepoint actions and condition expressions. Use the "tvariable"
4346 command to create, and "info tvariables" to view; see "Trace State
4347 Variables" in the manual for more detail.
4351 GDB now includes an option for defining fast tracepoints, which
4352 targets may implement more efficiently, such as by installing a jump
4353 into the target agent rather than a trap instruction. The resulting
4354 speedup can be by two orders of magnitude or more, although the
4355 tradeoff is that some program locations on some target architectures
4356 might not allow fast tracepoint installation, for instance if the
4357 instruction to be replaced is shorter than the jump. To request a
4358 fast tracepoint, use the "ftrace" command, with syntax identical to
4359 the regular trace command.
4361 ** Disconnected tracing
4363 It is now possible to detach GDB from the target while it is running
4364 a trace experiment, then reconnect later to see how the experiment
4365 is going. In addition, a new variable disconnected-tracing lets you
4366 tell the target agent whether to continue running a trace if the
4367 connection is lost unexpectedly.
4371 GDB now has the ability to save the trace buffer into a file, and
4372 then use that file as a target, similarly to you can do with
4373 corefiles. You can select trace frames, print data that was
4374 collected in them, and use tstatus to display the state of the
4375 tracing run at the moment that it was saved. To create a trace
4376 file, use "tsave <filename>", and to use it, do "target tfile
4379 ** Circular trace buffer
4381 You can ask the target agent to handle the trace buffer as a
4382 circular buffer, discarding the oldest trace frames to make room for
4383 newer ones, by setting circular-trace-buffer to on. This feature may
4384 not be available for all target agents.
4389 The disassemble command, when invoked with two arguments, now requires
4390 the arguments to be comma-separated.
4393 The info variables command now displays variable definitions. Files
4394 which only declare a variable are not shown.
4397 The source command is now capable of sourcing Python scripts.
4398 This feature is dependent on the debugger being build with Python
4401 Related to this enhancement is also the introduction of a new command
4402 "set script-extension" (see below).
4404 * New commands (for set/show, see "New options" below)
4406 record save [<FILENAME>]
4407 Save a file (in core file format) containing the process record
4408 execution log for replay debugging at a later time.
4410 record restore <FILENAME>
4411 Restore the process record execution log that was saved at an
4412 earlier time, for replay debugging.
4414 add-inferior [-copies <N>] [-exec <FILENAME>]
4417 clone-inferior [-copies <N>] [ID]
4418 Make a new inferior ready to execute the same program another
4419 inferior has loaded.
4424 maint info program-spaces
4425 List the program spaces loaded into GDB.
4427 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4428 show remote interrupt-sequence
4429 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4430 as the sequence to the remote target in order to interrupt the execution.
4431 Ctrl-C is a default. Some system prefers BREAK which is high level of
4432 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4433 Magic SysRq g. It is BREAK signal and character 'g'.
4435 set remote interrupt-on-connect [on | off]
4436 show remote interrupt-on-connect
4437 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4438 remote target when gdb connects to it. This is needed when you debug
4441 set remotebreak [on | off]
4443 Deprecated. Use "set/show remote interrupt-sequence" instead.
4445 tvariable $NAME [ = EXP ]
4446 Create or modify a trace state variable.
4449 List trace state variables and their values.
4451 delete tvariable $NAME ...
4452 Delete one or more trace state variables.
4455 Evaluate the given expressions without collecting anything into the
4456 trace buffer. (Valid in tracepoint actions only.)
4458 ftrace FN / FILE:LINE / *ADDR
4459 Define a fast tracepoint at the given function, line, or address.
4461 * New expression syntax
4463 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4464 GDB now parses 0b101010 identically with 42.
4468 set follow-exec-mode new|same
4469 show follow-exec-mode
4470 Control whether GDB reuses the same inferior across an exec call or
4471 creates a new one. This is useful to be able to restart the old
4472 executable after the inferior having done an exec call.
4474 set default-collect EXPR, ...
4475 show default-collect
4476 Define a list of expressions to be collected at each tracepoint.
4477 This is a useful way to ensure essential items are not overlooked,
4478 such as registers or a critical global variable.
4480 set disconnected-tracing
4481 show disconnected-tracing
4482 If set to 1, the target is instructed to continue tracing if it
4483 loses its connection to GDB. If 0, the target is to stop tracing
4486 set circular-trace-buffer
4487 show circular-trace-buffer
4488 If set to on, the target is instructed to use a circular trace buffer
4489 and discard the oldest trace frames instead of stopping the trace due
4490 to a full trace buffer. If set to off, the trace stops when the buffer
4491 fills up. Some targets may not support this.
4493 set script-extension off|soft|strict
4494 show script-extension
4495 If set to "off", the debugger does not perform any script language
4496 recognition, and all sourced files are assumed to be GDB scripts.
4497 If set to "soft" (the default), files are sourced according to
4498 filename extension, falling back to GDB scripts if the first
4500 If set to "strict", files are sourced according to filename extension.
4502 set ada trust-PAD-over-XVS on|off
4503 show ada trust-PAD-over-XVS
4504 If off, activate a workaround against a bug in the debugging information
4505 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4506 the GCC sources for more information about the GNAT encoding and
4507 PAD types in particular). It is always safe to set this option to
4508 off, but this introduces a slight performance penalty. The default
4511 * Python API Improvements
4513 ** GDB provides the new class gdb.LazyString. This is useful in
4514 some pretty-printing cases. The new method gdb.Value.lazy_string
4515 provides a simple way to create objects of this type.
4517 ** The fields returned by gdb.Type.fields now have an
4518 `is_base_class' attribute.
4520 ** The new method gdb.Type.range returns the range of an array type.
4522 ** The new method gdb.parse_and_eval can be used to parse and
4523 evaluate an expression.
4525 * New remote packets
4528 Define a trace state variable.
4531 Get the current value of a trace state variable.
4534 Set desired tracing behavior upon disconnection.
4537 Set the trace buffer to be linear or circular.
4540 Get data about the tracepoints currently in use.
4544 Process record now works correctly with hardware watchpoints.
4546 Multiple bug fixes have been made to the mips-irix port, making it
4547 much more reliable. In particular:
4548 - Debugging threaded applications is now possible again. Previously,
4549 GDB would hang while starting the program, or while waiting for
4550 the program to stop at a breakpoint.
4551 - Attaching to a running process no longer hangs.
4552 - An error occurring while loading a core file has been fixed.
4553 - Changing the value of the PC register now works again. This fixes
4554 problems observed when using the "jump" command, or when calling
4555 a function from GDB, or even when assigning a new value to $pc.
4556 - With the "finish" and "return" commands, the return value for functions
4557 returning a small array is now correctly printed.
4558 - It is now possible to break on shared library code which gets executed
4559 during a shared library init phase (code executed while executing
4560 their .init section). Previously, the breakpoint would have no effect.
4561 - GDB is now able to backtrace through the signal handler for
4562 non-threaded programs.
4564 PIE (Position Independent Executable) programs debugging is now supported.
4565 This includes debugging execution of PIC (Position Independent Code) shared
4566 libraries although for that, it should be possible to run such libraries as an
4569 *** Changes in GDB 7.0
4571 * GDB now has an interface for JIT compilation. Applications that
4572 dynamically generate code can create symbol files in memory and register
4573 them with GDB. For users, the feature should work transparently, and
4574 for JIT developers, the interface is documented in the GDB manual in the
4575 "JIT Compilation Interface" chapter.
4577 * Tracepoints may now be conditional. The syntax is as for
4578 breakpoints; either an "if" clause appended to the "trace" command,
4579 or the "condition" command is available. GDB sends the condition to
4580 the target for evaluation using the same bytecode format as is used
4581 for tracepoint actions.
4583 * The disassemble command now supports: an optional /r modifier, print the
4584 raw instructions in hex as well as in symbolic form, and an optional /m
4585 modifier to print mixed source+assembly.
4587 * Process record and replay
4589 In a architecture environment that supports ``process record and
4590 replay'', ``process record and replay'' target can record a log of
4591 the process execution, and replay it with both forward and reverse
4594 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4595 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4596 set execution-direction {forward|reverse}, for targets that support
4599 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4600 feature is available with a native GDB running on kernel version
4603 * GDB now has support for multi-byte and wide character sets on the
4604 target. Strings whose character type is wchar_t, char16_t, or
4605 char32_t are now correctly printed. GDB supports wide- and unicode-
4606 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4607 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4608 `printf'. This feature requires iconv to work properly; if your
4609 system does not have a working iconv, GDB can use GNU libiconv. See
4610 the installation instructions for more information.
4612 * GDB now supports automatic retrieval of shared library files from
4613 remote targets. To use this feature, specify a system root that begins
4614 with the `remote:' prefix, either via the `set sysroot' command or via
4615 the `--with-sysroot' configure-time option.
4617 * "info sharedlibrary" now takes an optional regex of libraries to show,
4618 and it now reports if a shared library has no debugging information.
4620 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4621 now complete on file names.
4623 * When completing in expressions, gdb will attempt to limit
4624 completions to allowable structure or union fields, where appropriate.
4625 For instance, consider:
4627 # struct example { int f1; double f2; };
4628 # struct example variable;
4631 If the user types TAB at the end of this command line, the available
4632 completions will be "f1" and "f2".
4634 * Inlined functions are now supported. They show up in backtraces, and
4635 the "step", "next", and "finish" commands handle them automatically.
4637 * GDB now supports the token-splicing (##) and stringification (#)
4638 operators when expanding macros. It also supports variable-arity
4641 * GDB now supports inspecting extra signal information, exported by
4642 the new $_siginfo convenience variable. The feature is currently
4643 implemented on linux ARM, i386 and amd64.
4645 * GDB can now display the VFP floating point registers and NEON vector
4646 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4647 can provide these registers (requires Linux 2.6.30 or later). Remote
4648 and simulator targets may also provide them.
4650 * New remote packets
4653 Search memory for a sequence of bytes.
4656 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4657 operation over reliable transport links. Use of this packet is
4658 controlled by the `set remote noack-packet' command.
4661 Kill the process with the specified process ID. Use this in preference
4662 to `k' when multiprocess protocol extensions are supported.
4665 Obtains additional operating system information
4669 Read or write additional signal information.
4671 * Removed remote protocol undocumented extension
4673 An undocumented extension to the remote protocol's `S' stop reply
4674 packet that permitted the stub to pass a process id was removed.
4675 Remote servers should use the `T' stop reply packet instead.
4677 * GDB now supports multiple function calling conventions according to the
4678 DWARF-2 DW_AT_calling_convention function attribute.
4680 * The SH target utilizes the aforementioned change to distinguish between gcc
4681 and Renesas calling convention. It also adds the new CLI commands
4682 `set/show sh calling-convention'.
4684 * GDB can now read compressed debug sections, as produced by GNU gold
4685 with the --compress-debug-sections=zlib flag.
4687 * 64-bit core files are now supported on AIX.
4689 * Thread switching is now supported on Tru64.
4691 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4692 which will be allocated using malloc later in program execution.
4694 * The qXfer:libraries:read remote protocol packet now allows passing a
4695 list of section offsets.
4697 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4698 conditions handling signals delivered during attach or thread creation
4699 have also been fixed.
4701 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4702 From the user's standpoint, all unqualified instances of True and False
4703 are treated as the standard definitions, regardless of context.
4705 * GDB now parses C++ symbol and type names more flexibly. For
4708 template<typename T> class C { };
4711 GDB will now correctly handle all of:
4713 ptype C<char const *>
4714 ptype C<char const*>
4715 ptype C<const char *>
4716 ptype C<const char*>
4718 * New features in the GDB remote stub, gdbserver
4720 - The "--wrapper" command-line argument tells gdbserver to use a
4721 wrapper program to launch programs for debugging.
4723 - On PowerPC and S/390 targets, it is now possible to use a single
4724 gdbserver executable to debug both 32-bit and 64-bit programs.
4725 (This requires gdbserver itself to be built as a 64-bit executable.)
4727 - gdbserver uses the new noack protocol mode for TCP connections to
4728 reduce communications latency, if also supported and enabled in GDB.
4730 - Support for the sparc64-linux-gnu target is now included in
4733 - The amd64-linux build of gdbserver now supports debugging both
4734 32-bit and 64-bit programs.
4736 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4737 now support hardware watchpoints, and will use them automatically
4742 GDB now has support for scripting using Python. Whether this is
4743 available is determined at configure time.
4745 New GDB commands can now be written in Python.
4747 * Ada tasking support
4749 Ada tasks can now be inspected in GDB. The following commands have
4753 Print the list of Ada tasks.
4755 Print detailed information about task number N.
4757 Print the task number of the current task.
4759 Switch the context of debugging to task number N.
4761 * Support for user-defined prefixed commands. The "define" command can
4762 add new commands to existing prefixes, e.g. "target".
4764 * Multi-inferior, multi-process debugging.
4766 GDB now has generalized support for multi-inferior debugging. See
4767 "Debugging Multiple Inferiors" in the manual for more information.
4768 Although availability still depends on target support, the command
4769 set is more uniform now. The GNU/Linux specific multi-forks support
4770 has been migrated to this new framework. This implied some user
4771 visible changes; see "New commands" and also "Removed commands"
4774 * Target descriptions can now describe the target OS ABI. See the
4775 "Target Description Format" section in the user manual for more
4778 * Target descriptions can now describe "compatible" architectures
4779 to indicate that the target can execute applications for a different
4780 architecture in addition to those for the main target architecture.
4781 See the "Target Description Format" section in the user manual for
4784 * Multi-architecture debugging.
4786 GDB now includes general supports for debugging applications on
4787 hybrid systems that use more than one single processor architecture
4788 at the same time. Each such hybrid architecture still requires
4789 specific support to be added. The only hybrid architecture supported
4790 in this version of GDB is the Cell Broadband Engine.
4792 * GDB now supports integrated debugging of Cell/B.E. applications that
4793 use both the PPU and SPU architectures. To enable support for hybrid
4794 Cell/B.E. debugging, you need to configure GDB to support both the
4795 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4796 --enable-targets configure option.
4798 * Non-stop mode debugging.
4800 For some targets, GDB now supports an optional mode of operation in
4801 which you can examine stopped threads while other threads continue
4802 to execute freely. This is referred to as non-stop mode, with the
4803 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4804 section in the user manual for more information.
4806 To be able to support remote non-stop debugging, a remote stub needs
4807 to implement the non-stop mode remote protocol extensions, as
4808 described in the "Remote Non-Stop" section of the user manual. The
4809 GDB remote stub, gdbserver, has been adjusted to support these
4810 extensions on linux targets.
4812 * New commands (for set/show, see "New options" below)
4814 catch syscall [NAME(S) | NUMBER(S)]
4815 Catch system calls. Arguments, which should be names of system
4816 calls or their numbers, mean catch only those syscalls. Without
4817 arguments, every syscall will be caught. When the inferior issues
4818 any of the specified syscalls, GDB will stop and announce the system
4819 call, both when it is called and when its call returns. This
4820 feature is currently available with a native GDB running on the
4821 Linux Kernel, under the following architectures: x86, x86_64,
4822 PowerPC and PowerPC64.
4824 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4826 Search memory for a sequence of bytes.
4828 maint set python print-stack
4829 maint show python print-stack
4830 Show a stack trace when an error is encountered in a Python script.
4833 Invoke CODE by passing it to the Python interpreter.
4838 These allow macros to be defined, undefined, and listed
4842 Show operating system information about processes.
4845 List the inferiors currently under GDB's control.
4848 Switch focus to inferior number NUM.
4851 Detach from inferior number NUM.
4854 Kill inferior number NUM.
4858 set spu stop-on-load
4859 show spu stop-on-load
4860 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4862 set spu auto-flush-cache
4863 show spu auto-flush-cache
4864 Control whether to automatically flush the software-managed cache
4865 during Cell/B.E. debugging.
4867 set sh calling-convention
4868 show sh calling-convention
4869 Control the calling convention used when calling SH target functions.
4872 show debug timestamp
4873 Control display of timestamps with GDB debugging output.
4875 set disassemble-next-line
4876 show disassemble-next-line
4877 Control display of disassembled source lines or instructions when
4880 set remote noack-packet
4881 show remote noack-packet
4882 Set/show the use of remote protocol QStartNoAckMode packet. See above
4883 under "New remote packets."
4885 set remote query-attached-packet
4886 show remote query-attached-packet
4887 Control use of remote protocol `qAttached' (query-attached) packet.
4889 set remote read-siginfo-object
4890 show remote read-siginfo-object
4891 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4894 set remote write-siginfo-object
4895 show remote write-siginfo-object
4896 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4899 set remote reverse-continue
4900 show remote reverse-continue
4901 Control use of remote protocol 'bc' (reverse-continue) packet.
4903 set remote reverse-step
4904 show remote reverse-step
4905 Control use of remote protocol 'bs' (reverse-step) packet.
4907 set displaced-stepping
4908 show displaced-stepping
4909 Control displaced stepping mode. Displaced stepping is a way to
4910 single-step over breakpoints without removing them from the debuggee.
4911 Also known as "out-of-line single-stepping".
4914 show debug displaced
4915 Control display of debugging info for displaced stepping.
4917 maint set internal-error
4918 maint show internal-error
4919 Control what GDB does when an internal error is detected.
4921 maint set internal-warning
4922 maint show internal-warning
4923 Control what GDB does when an internal warning is detected.
4928 Use a wrapper program to launch programs for debugging.
4930 set multiple-symbols (all|ask|cancel)
4931 show multiple-symbols
4932 The value of this variable can be changed to adjust the debugger behavior
4933 when an expression or a breakpoint location contains an ambiguous symbol
4934 name (an overloaded function name, for instance).
4936 set breakpoint always-inserted
4937 show breakpoint always-inserted
4938 Keep breakpoints always inserted in the target, as opposed to inserting
4939 them when resuming the target, and removing them when the target stops.
4940 This option can improve debugger performance on slow remote targets.
4942 set arm fallback-mode (arm|thumb|auto)
4943 show arm fallback-mode
4944 set arm force-mode (arm|thumb|auto)
4946 These commands control how ARM GDB determines whether instructions
4947 are ARM or Thumb. The default for both settings is auto, which uses
4948 the current CPSR value for instructions without symbols; previous
4949 versions of GDB behaved as if "set arm fallback-mode arm".
4951 set disable-randomization
4952 show disable-randomization
4953 Standalone programs run with the virtual address space randomization enabled
4954 by default on some platforms. This option keeps the addresses stable across
4955 multiple debugging sessions.
4959 Control whether other threads are stopped or not when some thread hits
4964 Requests that asynchronous execution is enabled in the target, if available.
4965 In this case, it's possible to resume target in the background, and interact
4966 with GDB while the target is running. "show target-async" displays the
4967 current state of asynchronous execution of the target.
4969 set target-wide-charset
4970 show target-wide-charset
4971 The target-wide-charset is the name of the character set that GDB
4972 uses when printing characters whose type is wchar_t.
4974 set tcp auto-retry (on|off)
4976 set tcp connect-timeout
4977 show tcp connect-timeout
4978 These commands allow GDB to retry failed TCP connections to a remote stub
4979 with a specified timeout period; this is useful if the stub is launched
4980 in parallel with GDB but may not be ready to accept connections immediately.
4982 set libthread-db-search-path
4983 show libthread-db-search-path
4984 Control list of directories which GDB will search for appropriate
4987 set schedule-multiple (on|off)
4988 show schedule-multiple
4989 Allow GDB to resume all threads of all processes or only threads of
4990 the current process.
4994 Use more aggressive caching for accesses to the stack. This improves
4995 performance of remote debugging (particularly backtraces) without
4996 affecting correctness.
4998 set interactive-mode (on|off|auto)
4999 show interactive-mode
5000 Control whether GDB runs in interactive mode (on) or not (off).
5001 When in interactive mode, GDB waits for the user to answer all
5002 queries. Otherwise, GDB does not wait and assumes the default
5003 answer. When set to auto (the default), GDB determines which
5004 mode to use based on the stdin settings.
5009 For program forks, this is replaced by the new more generic `info
5010 inferiors' command. To list checkpoints, you can still use the
5011 `info checkpoints' command, which was an alias for the `info forks'
5015 Replaced by the new `inferior' command. To switch between
5016 checkpoints, you can still use the `restart' command, which was an
5017 alias for the `fork' command.
5020 This is removed, since some targets don't have a notion of
5021 processes. To switch between processes, you can still use the
5022 `inferior' command using GDB's own inferior number.
5025 For program forks, this is replaced by the new more generic `kill
5026 inferior' command. To delete a checkpoint, you can still use the
5027 `delete checkpoint' command, which was an alias for the `delete
5031 For program forks, this is replaced by the new more generic `detach
5032 inferior' command. To detach a checkpoint, you can still use the
5033 `detach checkpoint' command, which was an alias for the `detach
5036 * New native configurations
5038 x86/x86_64 Darwin i[34567]86-*-darwin*
5040 x86_64 MinGW x86_64-*-mingw*
5044 Lattice Mico32 lm32-*
5045 x86 DICOS i[34567]86-*-dicos*
5046 x86_64 DICOS x86_64-*-dicos*
5049 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5050 (mingw32ce) debugging.
5056 These commands were actually not implemented on any target.
5058 *** Changes in GDB 6.8
5060 * New native configurations
5062 NetBSD/hppa hppa*-*netbsd*
5063 Xtensa GNU/Linux xtensa*-*-linux*
5067 NetBSD/hppa hppa*-*-netbsd*
5068 Xtensa GNU/Linux xtensa*-*-linux*
5070 * Change in command line behavior -- corefiles vs. process ids.
5072 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5073 attaching to process NUMBER fails, GDB no longer attempts to open a
5074 core file named NUMBER. Attaching to a program using the -c option
5075 is no longer supported. Instead, use the '-p' or '--pid' options.
5077 * GDB can now be built as a native debugger for debugging Windows x86
5078 (mingw32) Portable Executable (PE) programs.
5080 * Pending breakpoints no longer change their number when their address
5083 * GDB now supports breakpoints with multiple locations,
5084 including breakpoints on C++ constructors, inside C++ templates,
5085 and in inlined functions.
5087 * GDB's ability to debug optimized code has been improved. GDB more
5088 accurately identifies function bodies and lexical blocks that occupy
5089 more than one contiguous range of addresses.
5091 * Target descriptions can now describe registers for PowerPC.
5093 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5094 registers on PowerPC targets.
5096 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5097 targets even when the libthread_db library is not available.
5099 * The GDB remote stub, gdbserver, now supports the new file transfer
5100 commands (remote put, remote get, and remote delete).
5102 * The GDB remote stub, gdbserver, now supports run and attach in
5103 extended-remote mode.
5105 * hppa*64*-*-hpux11* target broken
5106 The debugger is unable to start a program and fails with the following
5107 error: "Error trying to get information about dynamic linker".
5108 The gdb-6.7 release is also affected.
5110 * GDB now supports the --enable-targets= configure option to allow
5111 building a single GDB executable that supports multiple remote
5112 target architectures.
5114 * GDB now supports debugging C and C++ programs which use the
5115 Decimal Floating Point extension. In addition, the PowerPC target
5116 now has a set of pseudo-registers to inspect decimal float values
5117 stored in two consecutive float registers.
5119 * The -break-insert MI command can optionally create pending
5122 * Improved support for debugging Ada
5123 Many improvements to the Ada language support have been made. These
5125 - Better support for Ada2005 interface types
5126 - Improved handling of arrays and slices in general
5127 - Better support for Taft-amendment types
5128 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5130 - Improved command completion in Ada
5133 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5138 set print frame-arguments (all|scalars|none)
5139 show print frame-arguments
5140 The value of this variable can be changed to control which argument
5141 values should be printed by the debugger when displaying a frame.
5146 Transfer files to and from a remote target, and delete remote files.
5153 Transfer files to and from a remote target, and delete remote files.
5155 * New remote packets
5162 Open, close, read, write, and delete files on the remote system.
5165 Attach to an existing process on the remote system, in extended-remote
5169 Run a new process on the remote system, in extended-remote mode.
5171 *** Changes in GDB 6.7
5173 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5174 bfd, libiberty and opcodes, as revealed by static analysis donated by
5175 Coverity, Inc. (http://scan.coverity.com).
5177 * When looking up multiply-defined global symbols, GDB will now prefer the
5178 symbol definition in the current shared library if it was built using the
5179 -Bsymbolic linker option.
5181 * When the Text User Interface (TUI) is not configured, GDB will now
5182 recognize the -tui command-line option and print a message that the TUI
5185 * The GDB remote stub, gdbserver, now has lower overhead for high
5186 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5188 * GDB for MIPS targets now autodetects whether a remote target provides
5189 32-bit or 64-bit register values.
5191 * Support for C++ member pointers has been improved.
5193 * GDB now understands XML target descriptions, which specify the
5194 target's overall architecture. GDB can read a description from
5195 a local file or over the remote serial protocol.
5197 * Vectors of single-byte data use a new integer type which is not
5198 automatically displayed as character or string data.
5200 * The /s format now works with the print command. It displays
5201 arrays of single-byte integers and pointers to single-byte integers
5204 * Target descriptions can now describe target-specific registers,
5205 for architectures which have implemented the support (currently
5206 only ARM, M68K, and MIPS).
5208 * GDB and the GDB remote stub, gdbserver, now support the XScale
5211 * The GDB remote stub, gdbserver, has been updated to support
5212 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5213 has been rewritten to use the standard GDB remote protocol.
5215 * GDB can now step into C++ functions which are called through thunks.
5217 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5219 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5220 layout. It also supports a TextSeg= and DataSeg= response when only
5221 segment base addresses (rather than offsets) are available.
5223 * The /i format now outputs any trailing branch delay slot instructions
5224 immediately following the last instruction within the count specified.
5226 * The GDB remote protocol "T" stop reply packet now supports a
5227 "library" response. Combined with the new "qXfer:libraries:read"
5228 packet, this response allows GDB to debug shared libraries on targets
5229 where the operating system manages the list of loaded libraries (e.g.
5230 Windows and SymbianOS).
5232 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5233 (DLLs) on Windows and Windows CE targets.
5235 * GDB now supports a faster verification that a .debug file matches its binary
5236 according to its build-id signature, if the signature is present.
5242 Enable or disable hardware flow control (RTS/CTS) on the serial port
5243 when debugging using remote targets.
5245 set mem inaccessible-by-default
5246 show mem inaccessible-by-default
5247 If the target supplies a memory map, for instance via the remote
5248 protocol's "qXfer:memory-map:read" packet, setting this variable
5249 prevents GDB from accessing memory outside the memory map. This
5250 is useful for targets with memory mapped registers or which react
5251 badly to accesses of unmapped address space.
5253 set breakpoint auto-hw
5254 show breakpoint auto-hw
5255 If the target supplies a memory map, for instance via the remote
5256 protocol's "qXfer:memory-map:read" packet, setting this variable
5257 lets GDB use hardware breakpoints automatically for memory regions
5258 where it can not use software breakpoints. This covers both the
5259 "break" command and internal breakpoints used for other commands
5260 including "next" and "finish".
5263 catch exception unhandled
5264 Stop the program execution when Ada exceptions are raised.
5267 Stop the program execution when an Ada assertion failed.
5271 Set an alternate system root for target files. This is a more
5272 general version of "set solib-absolute-prefix", which is now
5273 an alias to "set sysroot".
5276 Provide extended SPU facility status information. This set of
5277 commands is available only when debugging the Cell/B.E. SPU
5280 * New native configurations
5282 OpenBSD/sh sh*-*openbsd*
5285 unset tdesc filename
5287 Use the specified local file as an XML target description, and do
5288 not query the target for its built-in description.
5292 OpenBSD/sh sh*-*-openbsd*
5293 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5294 Toshiba Media Processor mep-elf
5296 * New remote packets
5299 Ignore the specified signals; pass them directly to the debugged program
5300 without stopping other threads or reporting them to GDB.
5302 qXfer:features:read:
5303 Read an XML target description from the target, which describes its
5308 Read or write contents of an spufs file on the target system. These
5309 packets are available only on the Cell/B.E. SPU architecture.
5311 qXfer:libraries:read:
5312 Report the loaded shared libraries. Combined with new "T" packet
5313 response, this packet allows GDB to debug shared libraries on
5314 targets where the operating system manages the list of loaded
5315 libraries (e.g. Windows and SymbianOS).
5319 Support for these obsolete configurations has been removed.
5327 i[34567]86-*-lynxos*
5328 i[34567]86-*-netware*
5329 i[34567]86-*-sco3.2v5*
5330 i[34567]86-*-sco3.2v4*
5332 i[34567]86-*-sysv4.2*
5335 i[34567]86-*-unixware2*
5336 i[34567]86-*-unixware*
5345 * Other removed features
5352 Various m68k-only ROM monitors.
5359 Various Renesas ROM monitors and debugging interfaces for SH and
5364 Support for a Macraigor serial interface to on-chip debugging.
5365 GDB does not directly support the newer parallel or USB
5370 A debug information format. The predecessor to DWARF 2 and
5371 DWARF 3, which are still supported.
5373 Support for the HP aCC compiler on HP-UX/PA-RISC
5375 SOM-encapsulated symbolic debugging information, automatic
5376 invocation of pxdb, and the aCC custom C++ ABI. This does not
5377 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5378 with aCC can still be debugged on an assembly level.
5380 MIPS ".pdr" sections
5382 A MIPS-specific format used to describe stack frame layout
5383 in debugging information.
5387 GDB could work with an older version of Guile to debug
5388 the interpreter and Scheme programs running in it.
5390 set mips stack-arg-size
5391 set mips saved-gpreg-size
5393 Use "set mips abi" to control parameter passing for MIPS.
5395 *** Changes in GDB 6.6
5400 Cell Broadband Engine SPU spu-elf
5402 * GDB can now be configured as a cross-debugger targeting native Windows
5403 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5404 running on a Windows system over TCP/IP to debug Windows programs.
5406 * The GDB remote stub, gdbserver, has been updated to support Windows and
5407 Cygwin debugging. Both single-threaded and multi-threaded programs are
5410 * The "set trust-readonly-sections" command works again. This command was
5411 broken in GDB 6.3, 6.4, and 6.5.
5413 * The "load" command now supports writing to flash memory, if the remote
5414 stub provides the required support.
5416 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5417 longer requires symbolic debug information (e.g. DWARF-2).
5422 unset substitute-path
5423 show substitute-path
5424 Manage a list of substitution rules that GDB uses to rewrite the name
5425 of the directories where the sources are located. This can be useful
5426 for instance when the sources were moved to a different location
5427 between compilation and debugging.
5431 Print each CLI command as it is executed. Each command is prefixed with
5432 a number of `+' symbols representing the nesting depth.
5433 The source command now has a `-v' option to enable the same feature.
5437 The ARM Demon monitor support (RDP protocol, "target rdp").
5439 Kernel Object Display, an embedded debugging feature which only worked with
5440 an obsolete version of Cisco IOS.
5442 The 'set download-write-size' and 'show download-write-size' commands.
5444 * New remote packets
5447 Tell a stub about GDB client features, and request remote target features.
5448 The first feature implemented is PacketSize, which allows the target to
5449 specify the size of packets it can handle - to minimize the number of
5450 packets required and improve performance when connected to a remote
5454 Fetch an OS auxilliary vector from the remote stub. This packet is a
5455 more efficient replacement for qPart:auxv:read.
5457 qXfer:memory-map:read:
5458 Fetch a memory map from the remote stub, including information about
5459 RAM, ROM, and flash memory devices.
5464 Erase and program a flash memory device.
5466 * Removed remote packets
5469 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5470 used it, and only gdbserver implemented it.
5472 *** Changes in GDB 6.5
5476 Renesas M32C/M16C m32c-elf
5478 Morpho Technologies ms1 ms1-elf
5482 init-if-undefined Initialize a convenience variable, but
5483 only if it doesn't already have a value.
5485 The following commands are presently only implemented for native GNU/Linux:
5487 checkpoint Save a snapshot of the program state.
5489 restart <n> Return the program state to a
5490 previously saved state.
5492 info checkpoints List currently saved checkpoints.
5494 delete-checkpoint <n> Delete a previously saved checkpoint.
5496 set|show detach-on-fork Tell gdb whether to detach from a newly
5497 forked process, or to keep debugging it.
5499 info forks List forks of the user program that
5500 are available to be debugged.
5502 fork <n> Switch to debugging one of several
5503 forks of the user program that are
5504 available to be debugged.
5506 delete-fork <n> Delete a fork from the list of forks
5507 that are available to be debugged (and
5508 kill the forked process).
5510 detach-fork <n> Delete a fork from the list of forks
5511 that are available to be debugged (and
5512 allow the process to continue).
5516 Morpho Technologies ms2 ms1-elf
5518 * Improved Windows host support
5520 GDB now builds as a cross debugger hosted on i686-mingw32, including
5521 native console support, and remote communications using either
5522 network sockets or serial ports.
5524 * Improved Modula-2 language support
5526 GDB can now print most types in the Modula-2 syntax. This includes:
5527 basic types, set types, record types, enumerated types, range types,
5528 pointer types and ARRAY types. Procedure var parameters are correctly
5529 printed and hexadecimal addresses and character constants are also
5530 written in the Modula-2 syntax. Best results can be obtained by using
5531 GNU Modula-2 together with the -gdwarf-2 command line option.
5535 The ARM rdi-share module.
5537 The Netware NLM debug server.
5539 *** Changes in GDB 6.4
5541 * New native configurations
5543 OpenBSD/arm arm*-*-openbsd*
5544 OpenBSD/mips64 mips64-*-openbsd*
5548 Morpho Technologies ms1 ms1-elf
5550 * New command line options
5552 --batch-silent As for --batch, but totally silent.
5553 --return-child-result The debugger will exist with the same value
5554 the child (debugged) program exited with.
5555 --eval-command COMMAND, -ex COMMAND
5556 Execute a single GDB CLI command. This may be
5557 specified multiple times and in conjunction
5558 with the --command (-x) option.
5560 * Deprecated commands removed
5562 The following commands, that were deprecated in 2000, have been
5566 set|show arm disassembly-flavor set|show arm disassembler
5567 othernames set arm disassembler
5568 set|show remotedebug set|show debug remote
5569 set|show archdebug set|show debug arch
5570 set|show eventdebug set|show debug event
5573 * New BSD user-level threads support
5575 It is now possible to debug programs using the user-level threads
5576 library on OpenBSD and FreeBSD. Currently supported (target)
5579 FreeBSD/amd64 x86_64-*-freebsd*
5580 FreeBSD/i386 i386-*-freebsd*
5581 OpenBSD/i386 i386-*-openbsd*
5583 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5584 are not yet supported.
5586 * New support for Matsushita MN10300 w/sim added
5587 (Work in progress). mn10300-elf.
5589 * REMOVED configurations and files
5591 VxWorks and the XDR protocol *-*-vxworks
5592 Motorola MCORE mcore-*-*
5593 National Semiconductor NS32000 ns32k-*-*
5595 * New "set print array-indexes" command
5597 After turning this setting "on", GDB prints the index of each element
5598 when displaying arrays. The default is "off" to preserve the previous
5601 * VAX floating point support
5603 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5605 * User-defined command support
5607 In addition to using $arg0..$arg9 for argument passing, it is now possible
5608 to use $argc to determine now many arguments have been passed. See the
5609 section on user-defined commands in the user manual for more information.
5611 *** Changes in GDB 6.3:
5613 * New command line option
5615 GDB now accepts -l followed by a number to set the timeout for remote
5618 * GDB works with GCC -feliminate-dwarf2-dups
5620 GDB now supports a more compact representation of DWARF-2 debug
5621 information using DW_FORM_ref_addr references. These are produced
5622 by GCC with the option -feliminate-dwarf2-dups and also by some
5623 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5624 to use -feliminate-dwarf2-dups.
5626 * Internationalization
5628 When supported by the host system, GDB will be built with
5629 internationalization (libintl). The task of marking up the sources is
5630 continued, we're looking forward to our first translation.
5634 Initial support for debugging programs compiled with the GNAT
5635 implementation of the Ada programming language has been integrated
5636 into GDB. In this release, support is limited to expression evaluation.
5638 * New native configurations
5640 GNU/Linux/m32r m32r-*-linux-gnu
5644 GDB's remote protocol now includes support for the 'p' packet. This
5645 packet is used to fetch individual registers from a remote inferior.
5647 * END-OF-LIFE registers[] compatibility module
5649 GDB's internal register infrastructure has been completely rewritten.
5650 The new infrastructure making possible the implementation of key new
5651 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5654 GDB 6.3 will be the last release to include the registers[]
5655 compatibility module that allowed out-of-date configurations to
5656 continue to work. This change directly impacts the following
5666 powerpc bdm protocol
5668 Unless there is activity to revive these configurations, they will be
5669 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5671 * OBSOLETE configurations and files
5673 Configurations that have been declared obsolete in this release have
5674 been commented out. Unless there is activity to revive these
5675 configurations, the next release of GDB will have their sources
5676 permanently REMOVED.
5685 *** Changes in GDB 6.2.1:
5687 * MIPS `break main; run' gave an heuristic-fence-post warning
5689 When attempting to run even a simple program, a warning about
5690 heuristic-fence-post being hit would be reported. This problem has
5693 * MIPS IRIX 'long double' crashed GDB
5695 When examining a long double variable, GDB would get a segmentation
5696 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5697 IRIX long double values).
5701 A bug in the VAX stack code was causing problems with the "next"
5702 command. This problem has been fixed.
5704 *** Changes in GDB 6.2:
5706 * Fix for ``many threads''
5708 On GNU/Linux systems that use the NPTL threads library, a program
5709 rapidly creating and deleting threads would confuse GDB leading to the
5712 ptrace: No such process.
5713 thread_db_get_info: cannot get thread info: generic error
5715 This problem has been fixed.
5717 * "-async" and "-noasync" options removed.
5719 Support for the broken "-noasync" option has been removed (it caused
5722 * New ``start'' command.
5724 This command runs the program until the beginning of the main procedure.
5726 * New BSD Kernel Data Access Library (libkvm) interface
5728 Using ``target kvm'' it is now possible to debug kernel core dumps and
5729 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5730 platforms. Currently supported (native-only) configurations are:
5732 FreeBSD/amd64 x86_64-*-freebsd*
5733 FreeBSD/i386 i?86-*-freebsd*
5734 NetBSD/i386 i?86-*-netbsd*
5735 NetBSD/m68k m68*-*-netbsd*
5736 NetBSD/sparc sparc-*-netbsd*
5737 OpenBSD/amd64 x86_64-*-openbsd*
5738 OpenBSD/i386 i?86-*-openbsd*
5739 OpenBSD/m68k m68*-openbsd*
5740 OpenBSD/sparc sparc-*-openbsd*
5742 * Signal trampoline code overhauled
5744 Many generic problems with GDB's signal handling code have been fixed.
5745 These include: backtraces through non-contiguous stacks; recognition
5746 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5747 call; backtrace through a signal trampoline; step into and out of
5748 signal handlers; and single-stepping in the signal trampoline.
5750 Please note that kernel bugs are a limiting factor here. These
5751 features have been shown to work on an s390 GNU/Linux system that
5752 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5754 * Cygwin support for DWARF 2 added.
5756 * New native configurations
5758 GNU/Linux/hppa hppa*-*-linux*
5759 OpenBSD/hppa hppa*-*-openbsd*
5760 OpenBSD/m68k m68*-*-openbsd*
5761 OpenBSD/m88k m88*-*-openbsd*
5762 OpenBSD/powerpc powerpc-*-openbsd*
5763 NetBSD/vax vax-*-netbsd*
5764 OpenBSD/vax vax-*-openbsd*
5766 * END-OF-LIFE frame compatibility module
5768 GDB's internal frame infrastructure has been completely rewritten.
5769 The new infrastructure making it possible to support key new features
5770 including DWARF 2 Call Frame Information. To aid in the task of
5771 migrating old configurations to this new infrastructure, a
5772 compatibility module, that allowed old configurations to continue to
5773 work, was also included.
5775 GDB 6.2 will be the last release to include this frame compatibility
5776 module. This change directly impacts the following configurations:
5786 Unless there is activity to revive these configurations, they will be
5787 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5789 * REMOVED configurations and files
5791 Sun 3, running SunOS 3 m68*-*-sunos3*
5792 Sun 3, running SunOS 4 m68*-*-sunos4*
5793 Sun 2, running SunOS 3 m68000-*-sunos3*
5794 Sun 2, running SunOS 4 m68000-*-sunos4*
5795 Motorola 680x0 running LynxOS m68*-*-lynxos*
5796 AT&T 3b1/Unix pc m68*-att-*
5797 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5798 decstation mips-dec-* mips-little-*
5799 riscos mips-*-riscos* mips-*-sysv*
5800 sonymips mips-sony-*
5801 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5803 *** Changes in GDB 6.1.1:
5805 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5807 The TUI (Text-mode User Interface) is now built as part of a default
5808 GDB configuration. It is enabled by either selecting the TUI with the
5809 command line option "-i=tui" or by running the separate "gdbtui"
5810 program. For more information on the TUI, see the manual "Debugging
5813 * Pending breakpoint support (also included in GDB 6.1)
5815 Support has been added to allow you to specify breakpoints in shared
5816 libraries that have not yet been loaded. If a breakpoint location
5817 cannot be found, and the "breakpoint pending" option is set to auto,
5818 GDB queries you if you wish to make the breakpoint pending on a future
5819 shared-library load. If and when GDB resolves the breakpoint symbol,
5820 the pending breakpoint is removed as one or more regular breakpoints
5823 Pending breakpoints are very useful for GCJ Java debugging.
5825 * Fixed ISO-C build problems
5827 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5828 non ISO-C code that stopped them being built using a more strict ISO-C
5829 compiler (e.g., IBM's C compiler).
5831 * Fixed build problem on IRIX 5
5833 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5834 wasn't able to compile compile on an IRIX 5 system.
5836 * Added execute permission to gdb/gdbserver/configure
5838 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5839 permission. This bug would cause configure to fail on a number of
5840 systems (Solaris, IRIX). Ref: server/519.
5842 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5844 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5845 has been updated to use constant array sizes.
5847 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5849 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5850 its generated DWARF Call Frame Info. This encoding was causing GDB to
5851 panic, that panic has been fixed. Ref: gdb/1628.
5853 * Fixed a problem when examining parameters in shared library code.
5855 When examining parameters in optimized shared library code generated
5856 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5857 not available''. GDB now correctly displays the variable's value.
5859 *** Changes in GDB 6.1:
5861 * Removed --with-mmalloc
5863 Support for the mmalloc memory manager has been removed, as it
5864 conflicted with the internal gdb byte cache.
5866 * Changes in AMD64 configurations
5868 The AMD64 target now includes the %cs and %ss registers. As a result
5869 the AMD64 remote protocol has changed; this affects the floating-point
5870 and SSE registers. If you rely on those registers for your debugging,
5871 you should upgrade gdbserver on the remote side.
5873 * Revised SPARC target
5875 The SPARC target has been completely revised, incorporating the
5876 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5877 support for LynxOS and SunOS 4 has been dropped. Calling functions
5878 from within GDB on operating systems with a non-executable stack
5879 (Solaris, OpenBSD) now works.
5883 GDB has a new C++ demangler which does a better job on the mangled
5884 names generated by current versions of g++. It also runs faster, so
5885 with this and other changes gdb should now start faster on large C++
5888 * DWARF 2 Location Expressions
5890 GDB support for location expressions has been extended to support function
5891 arguments and frame bases. Older versions of GDB could crash when they
5894 * C++ nested types and namespaces
5896 GDB's support for nested types and namespaces in C++ has been
5897 improved, especially if you use the DWARF 2 debugging format. (This
5898 is the default for recent versions of GCC on most platforms.)
5899 Specifically, if you have a class "Inner" defined within a class or
5900 namespace "Outer", then GDB realizes that the class's name is
5901 "Outer::Inner", not simply "Inner". This should greatly reduce the
5902 frequency of complaints about not finding RTTI symbols. In addition,
5903 if you are stopped at inside of a function defined within a namespace,
5904 GDB modifies its name lookup accordingly.
5906 * New native configurations
5908 NetBSD/amd64 x86_64-*-netbsd*
5909 OpenBSD/amd64 x86_64-*-openbsd*
5910 OpenBSD/alpha alpha*-*-openbsd*
5911 OpenBSD/sparc sparc-*-openbsd*
5912 OpenBSD/sparc64 sparc64-*-openbsd*
5914 * New debugging protocols
5916 M32R with SDI protocol m32r-*-elf*
5918 * "set prompt-escape-char" command deleted.
5920 The command "set prompt-escape-char" has been deleted. This command,
5921 and its very obscure effect on GDB's prompt, was never documented,
5922 tested, nor mentioned in the NEWS file.
5924 * OBSOLETE configurations and files
5926 Configurations that have been declared obsolete in this release have
5927 been commented out. Unless there is activity to revive these
5928 configurations, the next release of GDB will have their sources
5929 permanently REMOVED.
5931 Sun 3, running SunOS 3 m68*-*-sunos3*
5932 Sun 3, running SunOS 4 m68*-*-sunos4*
5933 Sun 2, running SunOS 3 m68000-*-sunos3*
5934 Sun 2, running SunOS 4 m68000-*-sunos4*
5935 Motorola 680x0 running LynxOS m68*-*-lynxos*
5936 AT&T 3b1/Unix pc m68*-att-*
5937 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5938 decstation mips-dec-* mips-little-*
5939 riscos mips-*-riscos* mips-*-sysv*
5940 sonymips mips-sony-*
5941 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5943 * REMOVED configurations and files
5945 SGI Irix-4.x mips-sgi-irix4 or iris4
5946 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5947 Z8000 simulator z8k-zilog-none or z8ksim
5948 Matsushita MN10200 w/simulator mn10200-*-*
5949 H8/500 simulator h8500-hitachi-hms or h8500hms
5950 HP/PA running BSD hppa*-*-bsd*
5951 HP/PA running OSF/1 hppa*-*-osf*
5952 HP/PA Pro target hppa*-*-pro*
5953 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5954 386BSD i[3456]86-*-bsd*
5955 Sequent family i[3456]86-sequent-sysv4*
5956 i[3456]86-sequent-sysv*
5957 i[3456]86-sequent-bsd*
5958 SPARC running LynxOS sparc-*-lynxos*
5959 SPARC running SunOS 4 sparc-*-sunos4*
5960 Tsqware Sparclet sparclet-*-*
5961 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5963 *** Changes in GDB 6.0:
5967 Support for debugging the Objective-C programming language has been
5968 integrated into GDB.
5970 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
5972 DWARF 2's Call Frame Information makes available compiler generated
5973 information that more exactly describes the program's run-time stack.
5974 By using this information, GDB is able to provide more robust stack
5977 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
5978 have been updated to use a new backtrace mechanism which includes
5979 DWARF 2 CFI support.
5983 GDB's remote protocol has been extended to include support for hosted
5984 file I/O (where the remote target uses GDB's file system). See GDB's
5985 remote protocol documentation for details.
5987 * All targets using the new architecture framework.
5989 All of GDB's targets have been updated to use the new internal
5990 architecture framework. The way is now open for future GDB releases
5991 to include cross-architecture native debugging support (i386 on amd64,
5994 * GNU/Linux's Thread Local Storage (TLS)
5996 GDB now includes support for for the GNU/Linux implementation of
5997 per-thread variables.
5999 * GNU/Linux's Native POSIX Thread Library (NPTL)
6001 GDB's thread code has been updated to work with either the new
6002 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6004 * Separate debug info.
6006 GDB, in conjunction with BINUTILS, now supports a mechanism for
6007 automatically loading debug information from a separate file. Instead
6008 of shipping full debug and non-debug versions of system libraries,
6009 system integrators can now instead ship just the stripped libraries
6010 and optional debug files.
6012 * DWARF 2 Location Expressions
6014 DWARF 2 Location Expressions allow the compiler to more completely
6015 describe the location of variables (even in optimized code) to the
6018 GDB now includes preliminary support for location expressions (support
6019 for DW_OP_piece is still missing).
6023 A number of long standing bugs that caused GDB to die while starting a
6024 Java application have been fixed. GDB's Java support is now
6025 considered "useable".
6027 * GNU/Linux support for fork, vfork, and exec.
6029 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6030 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6033 * GDB supports logging output to a file
6035 There are two new commands, "set logging" and "show logging", which can be
6036 used to capture GDB's output to a file.
6038 * The meaning of "detach" has changed for gdbserver
6040 The "detach" command will now resume the application, as documented. To
6041 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6044 * d10v, m68hc11 `regs' command deprecated
6046 The `info registers' command has been updated so that it displays the
6047 registers using a format identical to the old `regs' command.
6051 A new command, "maint set profile on/off", has been added. This command can
6052 be used to enable or disable profiling while running GDB, to profile a
6053 session or a set of commands. In addition there is a new configure switch,
6054 "--enable-profiling", which will cause GDB to be compiled with profiling
6055 data, for more informative profiling results.
6057 * Default MI syntax changed to "mi2".
6059 The default MI (machine interface) syntax, enabled by the command line
6060 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6061 "mi1", can be enabled by specifying the option "-i=mi1".
6063 Support for the original "mi0" syntax (included in GDB 5.0) has been
6066 Fix for gdb/192: removed extraneous space when displaying frame level.
6067 Fix for gdb/672: update changelist is now output in mi list format.
6068 Fix for gdb/702: a -var-assign that updates the value now shows up
6069 in a subsequent -var-update.
6071 * New native configurations.
6073 FreeBSD/amd64 x86_64-*-freebsd*
6075 * Multi-arched targets.
6077 HP/PA HPUX11 hppa*-*-hpux*
6078 Renesas M32R/D w/simulator m32r-*-elf*
6080 * OBSOLETE configurations and files
6082 Configurations that have been declared obsolete in this release have
6083 been commented out. Unless there is activity to revive these
6084 configurations, the next release of GDB will have their sources
6085 permanently REMOVED.
6087 Z8000 simulator z8k-zilog-none or z8ksim
6088 Matsushita MN10200 w/simulator mn10200-*-*
6089 H8/500 simulator h8500-hitachi-hms or h8500hms
6090 HP/PA running BSD hppa*-*-bsd*
6091 HP/PA running OSF/1 hppa*-*-osf*
6092 HP/PA Pro target hppa*-*-pro*
6093 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6094 Sequent family i[3456]86-sequent-sysv4*
6095 i[3456]86-sequent-sysv*
6096 i[3456]86-sequent-bsd*
6097 Tsqware Sparclet sparclet-*-*
6098 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6100 * REMOVED configurations and files
6103 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6104 IBM AIX PS/2 i[3456]86-*-aix
6105 i386 running Mach 3.0 i[3456]86-*-mach3*
6106 i386 running Mach i[3456]86-*-mach*
6107 i386 running OSF/1 i[3456]86-*osf1mk*
6108 HP/Apollo 68k Family m68*-apollo*-sysv*,
6110 m68*-hp-bsd*, m68*-hp-hpux*
6111 Argonaut Risc Chip (ARC) arc-*-*
6112 Mitsubishi D30V d30v-*-*
6113 Fujitsu FR30 fr30-*-elf*
6114 OS/9000 i[34]86-*-os9k
6115 I960 with MON960 i960-*-coff
6117 * MIPS $fp behavior changed
6119 The convenience variable $fp, for the MIPS, now consistently returns
6120 the address of the current frame's base. Previously, depending on the
6121 context, $fp could refer to either $sp or the current frame's base
6122 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6123 The GNU Source-Level Debugger''.
6125 *** Changes in GDB 5.3:
6127 * GNU/Linux shared library multi-threaded performance improved.
6129 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6130 `/proc', in preference to `ptrace' for memory reads. This may result
6131 in an improvement in the start-up time of multi-threaded, shared
6132 library applications when run under GDB. One GDB user writes: ``loads
6133 shared libs like mad''.
6135 * ``gdbserver'' now supports multi-threaded applications on some targets
6137 Support for debugging multi-threaded applications which use
6138 the GNU/Linux LinuxThreads package has been added for
6139 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6140 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6142 * GDB now supports C/C++ preprocessor macros.
6144 GDB now expands preprocessor macro invocations in C/C++ expressions,
6145 and provides various commands for showing macro definitions and how
6148 The new command `macro expand EXPRESSION' expands any macro
6149 invocations in expression, and shows the result.
6151 The new command `show macro MACRO-NAME' shows the definition of the
6152 macro named MACRO-NAME, and where it was defined.
6154 Most compilers don't include information about macros in the debugging
6155 information by default. In GCC 3.1, for example, you need to compile
6156 your program with the options `-gdwarf-2 -g3'. If the macro
6157 information is present in the executable, GDB will read it.
6159 * Multi-arched targets.
6161 DEC Alpha (partial) alpha*-*-*
6162 DEC VAX (partial) vax-*-*
6164 National Semiconductor NS32000 (partial) ns32k-*-*
6165 Motorola 68000 (partial) m68k-*-*
6166 Motorola MCORE mcore-*-*
6170 Fujitsu FRV architecture added by Red Hat frv*-*-*
6173 * New native configurations
6175 Alpha NetBSD alpha*-*-netbsd*
6176 SH NetBSD sh*-*-netbsdelf*
6177 MIPS NetBSD mips*-*-netbsd*
6178 UltraSPARC NetBSD sparc64-*-netbsd*
6180 * OBSOLETE configurations and files
6182 Configurations that have been declared obsolete in this release have
6183 been commented out. Unless there is activity to revive these
6184 configurations, the next release of GDB will have their sources
6185 permanently REMOVED.
6187 Mitsubishi D30V d30v-*-*
6188 OS/9000 i[34]86-*-os9k
6189 IBM AIX PS/2 i[3456]86-*-aix
6190 Fujitsu FR30 fr30-*-elf*
6191 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6192 Argonaut Risc Chip (ARC) arc-*-*
6193 i386 running Mach 3.0 i[3456]86-*-mach3*
6194 i386 running Mach i[3456]86-*-mach*
6195 i386 running OSF/1 i[3456]86-*osf1mk*
6196 HP/Apollo 68k Family m68*-apollo*-sysv*,
6198 m68*-hp-bsd*, m68*-hp-hpux*
6199 I960 with MON960 i960-*-coff
6201 * OBSOLETE languages
6203 CHILL, a Pascal like language used by telecommunications companies.
6205 * REMOVED configurations and files
6207 AMD 29k family via UDI a29k-amd-udi, udi29k
6208 A29K VxWorks a29k-*-vxworks
6209 AMD 29000 embedded, using EBMON a29k-none-none
6210 AMD 29000 embedded with COFF a29k-none-coff
6211 AMD 29000 embedded with a.out a29k-none-aout
6213 testsuite/gdb.hp/gdb.threads-hp/ directory
6215 * New command "set max-user-call-depth <nnn>"
6217 This command allows the user to limit the call depth of user-defined
6218 commands. The default is 1024.
6220 * Changes in FreeBSD/i386 native debugging.
6222 Support for the "generate-core-file" has been added.
6224 * New commands "dump", "append", and "restore".
6226 These commands allow data to be copied from target memory
6227 to a bfd-format or binary file (dump and append), and back
6228 from a file into memory (restore).
6230 * Improved "next/step" support on multi-processor Alpha Tru64.
6232 The previous single-step mechanism could cause unpredictable problems,
6233 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6234 of a software single-step mechanism prevents this.
6236 *** Changes in GDB 5.2.1:
6244 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6245 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6246 Fix, by Joel Brobecker imported from mainline.
6248 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6249 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6250 Fix, by Fred Fish, imported from mainline.
6252 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6253 Surprisingly enough, it works now.
6254 By Michal Ludvig, imported from mainline.
6256 i386 hardware watchpoint support:
6257 avoid misses on second run for some targets.
6258 By Pierre Muller, imported from mainline.
6260 *** Changes in GDB 5.2:
6262 * New command "set trust-readonly-sections on[off]".
6264 This command is a hint that tells gdb that read-only sections
6265 really are read-only (ie. that their contents will not change).
6266 In this mode, gdb will go to the object file rather than the
6267 target to read memory from read-only sections (such as ".text").
6268 This can be a significant performance improvement on some
6269 (notably embedded) targets.
6271 * New command "generate-core-file" (or "gcore").
6273 This new gdb command allows the user to drop a core file of the child
6274 process state at any time. So far it's been implemented only for
6275 GNU/Linux and Solaris, but should be relatively easily ported to other
6276 hosts. Argument is core file name (defaults to core.<pid>).
6278 * New command line option
6280 GDB now accepts --pid or -p followed by a process id.
6282 * Change in command line behavior -- corefiles vs. process ids.
6284 There is a subtle behavior in the way in which GDB handles
6285 command line arguments. The first non-flag argument is always
6286 a program to debug, but the second non-flag argument may either
6287 be a corefile or a process id. Previously, GDB would attempt to
6288 open the second argument as a corefile, and if that failed, would
6289 issue a superfluous error message and then attempt to attach it as
6290 a process. Now, if the second argument begins with a non-digit,
6291 it will be treated as a corefile. If it begins with a digit,
6292 GDB will attempt to attach it as a process, and if no such process
6293 is found, will then attempt to open it as a corefile.
6295 * Changes in ARM configurations.
6297 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6298 configuration is fully multi-arch.
6300 * New native configurations
6302 ARM NetBSD arm*-*-netbsd*
6303 x86 OpenBSD i[3456]86-*-openbsd*
6304 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6305 Sparc64 running FreeBSD sparc64-*-freebsd*
6309 Sanyo XStormy16 xstormy16-elf
6311 * OBSOLETE configurations and files
6313 Configurations that have been declared obsolete in this release have
6314 been commented out. Unless there is activity to revive these
6315 configurations, the next release of GDB will have their sources
6316 permanently REMOVED.
6318 AMD 29k family via UDI a29k-amd-udi, udi29k
6319 A29K VxWorks a29k-*-vxworks
6320 AMD 29000 embedded, using EBMON a29k-none-none
6321 AMD 29000 embedded with COFF a29k-none-coff
6322 AMD 29000 embedded with a.out a29k-none-aout
6324 testsuite/gdb.hp/gdb.threads-hp/ directory
6326 * REMOVED configurations and files
6328 TI TMS320C80 tic80-*-*
6330 PowerPC Solaris powerpcle-*-solaris*
6331 PowerPC Windows NT powerpcle-*-cygwin32
6332 PowerPC Netware powerpc-*-netware*
6333 Harris/CXUX m88k m88*-harris-cxux*
6334 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6335 ns32k-utek-sysv* ns32k-utek-*
6336 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6337 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6338 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6339 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6340 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6342 * Changes to command line processing
6344 The new `--args' feature can be used to specify command-line arguments
6345 for the inferior from gdb's command line.
6347 * Changes to key bindings
6349 There is a new `operate-and-get-next' function bound to `C-o'.
6351 *** Changes in GDB 5.1.1
6353 Fix compile problem on DJGPP.
6355 Fix a problem with floating-point registers on the i386 being
6358 Fix to stop GDB crashing on .debug_str debug info.
6360 Numerous documentation fixes.
6362 Numerous testsuite fixes.
6364 *** Changes in GDB 5.1:
6366 * New native configurations
6368 Alpha FreeBSD alpha*-*-freebsd*
6369 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6370 MIPS GNU/Linux mips*-*-linux*
6371 MIPS SGI Irix 6.x mips*-sgi-irix6*
6372 ia64 AIX ia64-*-aix*
6373 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6377 Motorola 68HC11 and 68HC12 m68hc11-elf
6379 UltraSparc running GNU/Linux sparc64-*-linux*
6381 * OBSOLETE configurations and files
6383 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6384 Harris/CXUX m88k m88*-harris-cxux*
6385 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6386 ns32k-utek-sysv* ns32k-utek-*
6387 TI TMS320C80 tic80-*-*
6389 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6390 PowerPC Solaris powerpcle-*-solaris*
6391 PowerPC Windows NT powerpcle-*-cygwin32
6392 PowerPC Netware powerpc-*-netware*
6393 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6394 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6395 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6396 Apple Macintosh (MPW) host N/A
6398 stuff.c (Program to stuff files into a specially prepared space in kdb)
6399 kdb-start.c (Main loop for the standalone kernel debugger)
6401 Configurations that have been declared obsolete in this release have
6402 been commented out. Unless there is activity to revive these
6403 configurations, the next release of GDB will have their sources
6404 permanently REMOVED.
6406 * REMOVED configurations and files
6408 Altos 3068 m68*-altos-*
6409 Convex c1-*-*, c2-*-*
6411 ARM RISCix arm-*-* (as host)
6415 * GDB has been converted to ISO C.
6417 GDB's source code has been converted to ISO C. In particular, the
6418 sources are fully protoized, and rely on standard headers being
6423 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6425 * The MI enabled by default.
6427 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6428 revised and enabled by default. Packages which use GDB as a debugging
6429 engine behind a UI or another front end are encouraged to switch to
6430 using the GDB/MI interface, instead of the old annotations interface
6431 which is now deprecated.
6433 * Support for debugging Pascal programs.
6435 GDB now includes support for debugging Pascal programs. The following
6436 main features are supported:
6438 - Pascal-specific data types such as sets;
6440 - automatic recognition of Pascal sources based on file-name
6443 - Pascal-style display of data types, variables, and functions;
6445 - a Pascal expression parser.
6447 However, some important features are not yet supported.
6449 - Pascal string operations are not supported at all;
6451 - there are some problems with boolean types;
6453 - Pascal type hexadecimal constants are not supported
6454 because they conflict with the internal variables format;
6456 - support for Pascal objects and classes is not full yet;
6458 - unlike Pascal, GDB is case-sensitive for symbol names.
6460 * Changes in completion.
6462 Commands such as `shell', `run' and `set args', which pass arguments
6463 to inferior programs, now complete on file names, similar to what
6464 users expect at the shell prompt.
6466 Commands which accept locations, such as `disassemble', `print',
6467 `breakpoint', `until', etc. now complete on filenames as well as
6468 program symbols. Thus, if you type "break foob TAB", and the source
6469 files linked into the programs include `foobar.c', that file name will
6470 be one of the candidates for completion. However, file names are not
6471 considered for completion after you typed a colon that delimits a file
6472 name from a name of a function in that file, as in "break foo.c:bar".
6474 `set demangle-style' completes on available demangling styles.
6476 * New platform-independent commands:
6478 It is now possible to define a post-hook for a command as well as a
6479 hook that runs before the command. For more details, see the
6480 documentation of `hookpost' in the GDB manual.
6482 * Changes in GNU/Linux native debugging.
6484 Support for debugging multi-threaded programs has been completely
6485 revised for all platforms except m68k and sparc. You can now debug as
6486 many threads as your system allows you to have.
6488 Attach/detach is supported for multi-threaded programs.
6490 Support for SSE registers was added for x86. This doesn't work for
6491 multi-threaded programs though.
6493 * Changes in MIPS configurations.
6495 Multi-arch support is enabled for all MIPS configurations.
6497 GDB can now be built as native debugger on SGI Irix 6.x systems for
6498 debugging n32 executables. (Debugging 64-bit executables is not yet
6501 * Unified support for hardware watchpoints in all x86 configurations.
6503 Most (if not all) native x86 configurations support hardware-assisted
6504 breakpoints and watchpoints in a unified manner. This support
6505 implements debug register sharing between watchpoints, which allows to
6506 put a virtually infinite number of watchpoints on the same address,
6507 and also supports watching regions up to 16 bytes with several debug
6510 The new maintenance command `maintenance show-debug-regs' toggles
6511 debugging print-outs in functions that insert, remove, and test
6512 watchpoints and hardware breakpoints.
6514 * Changes in the DJGPP native configuration.
6516 New command ``info dos sysinfo'' displays assorted information about
6517 the CPU, OS, memory, and DPMI server.
6519 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6520 display information about segment descriptors stored in GDT, LDT, and
6523 New commands ``info dos pde'' and ``info dos pte'' display entries
6524 from Page Directory and Page Tables (for now works with CWSDPMI only).
6525 New command ``info dos address-pte'' displays the Page Table entry for
6526 a given linear address.
6528 GDB can now pass command lines longer than 126 characters to the
6529 program being debugged (requires an update to the libdbg.a library
6530 which is part of the DJGPP development kit).
6532 DWARF2 debug info is now supported.
6534 It is now possible to `step' and `next' through calls to `longjmp'.
6536 * Changes in documentation.
6538 All GDB documentation was converted to GFDL, the GNU Free
6539 Documentation License.
6541 Tracepoints-related commands are now fully documented in the GDB
6544 TUI, the Text-mode User Interface, is now documented in the manual.
6546 Tracepoints-related commands are now fully documented in the GDB
6549 The "GDB Internals" manual now has an index. It also includes
6550 documentation of `ui_out' functions, GDB coding standards, x86
6551 hardware watchpoints, and memory region attributes.
6553 * GDB's version number moved to ``version.in''
6555 The Makefile variable VERSION has been replaced by the file
6556 ``version.in''. People creating GDB distributions should update the
6557 contents of this file.
6561 GUD support is now a standard part of the EMACS distribution.
6563 *** Changes in GDB 5.0:
6565 * Improved support for debugging FP programs on x86 targets
6567 Unified and much-improved support for debugging floating-point
6568 programs on all x86 targets. In particular, ``info float'' now
6569 displays the FP registers in the same format on all x86 targets, with
6570 greater level of detail.
6572 * Improvements and bugfixes in hardware-assisted watchpoints
6574 It is now possible to watch array elements, struct members, and
6575 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6576 on x86 targets no longer erroneously trigger when the address is
6579 * Improvements in the native DJGPP version of GDB
6581 The distribution now includes all the scripts and auxiliary files
6582 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6583 machines ``out of the box''.
6585 The DJGPP version can now debug programs that use signals. It is
6586 possible to catch signals that happened in the debuggee, deliver
6587 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6588 would kill the program being debugged.) Programs that hook hardware
6589 interrupts (keyboard, timer, etc.) can also be debugged.
6591 It is now possible to debug DJGPP programs that redirect their
6592 standard handles or switch them to raw (as opposed to cooked) mode, or
6593 even close them. The command ``run < foo > bar'' works as expected,
6594 and ``info terminal'' reports useful information about the debuggee's
6595 terminal, including raw/cooked mode, redirection, etc.
6597 The DJGPP version now uses termios functions for console I/O, which
6598 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6601 DOS-style file names with drive letters are now fully supported by
6604 It is now possible to debug DJGPP programs that switch their working
6605 directory. It is also possible to rerun the debuggee any number of
6606 times without restarting GDB; thus, you can use the same setup,
6607 breakpoints, etc. for many debugging sessions.
6609 * New native configurations
6611 ARM GNU/Linux arm*-*-linux*
6612 PowerPC GNU/Linux powerpc-*-linux*
6616 Motorola MCore mcore-*-*
6617 x86 VxWorks i[3456]86-*-vxworks*
6618 PowerPC VxWorks powerpc-*-vxworks*
6619 TI TMS320C80 tic80-*-*
6621 * OBSOLETE configurations
6623 Altos 3068 m68*-altos-*
6624 Convex c1-*-*, c2-*-*
6626 ARM RISCix arm-*-* (as host)
6629 Configurations that have been declared obsolete will be commented out,
6630 but the code will be left in place. If there is no activity to revive
6631 these configurations before the next release of GDB, the sources will
6632 be permanently REMOVED.
6634 * Gould support removed
6636 Support for the Gould PowerNode and NP1 has been removed.
6638 * New features for SVR4
6640 On SVR4 native platforms (such as Solaris), if you attach to a process
6641 without first loading a symbol file, GDB will now attempt to locate and
6642 load symbols from the running process's executable file.
6644 * Many C++ enhancements
6646 C++ support has been greatly improved. Overload resolution now works properly
6647 in almost all cases. RTTI support is on the way.
6649 * Remote targets can connect to a sub-program
6651 A popen(3) style serial-device has been added. This device starts a
6652 sub-process (such as a stand-alone simulator) and then communicates
6653 with that. The sub-program to run is specified using the syntax
6654 ``|<program> <args>'' vis:
6656 (gdb) set remotedebug 1
6657 (gdb) target extended-remote |mn10300-elf-sim program-args
6659 * MIPS 64 remote protocol
6661 A long standing bug in the mips64 remote protocol where by GDB
6662 expected certain 32 bit registers (ex SR) to be transfered as 32
6663 instead of 64 bits has been fixed.
6665 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6666 added to provide backward compatibility with older versions of GDB.
6668 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6670 The command ``set remotebinarydownload'' command has been replaced by
6671 ``set remote X-packet''. Other commands in ``set remote'' family
6672 include ``set remote P-packet''.
6674 * Breakpoint commands accept ranges.
6676 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6677 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6678 ``tracepoint passcount'' also accepts a range of tracepoints.
6680 * ``apropos'' command added.
6682 The ``apropos'' command searches through command names and
6683 documentation strings, printing out matches, making it much easier to
6684 try to find a command that does what you are looking for.
6688 A new machine oriented interface (MI) has been added to GDB. This
6689 interface is designed for debug environments running GDB as a separate
6690 process. This is part of the long term libGDB project. See the
6691 "GDB/MI" chapter of the GDB manual for further information. It can be
6692 enabled by configuring with:
6694 .../configure --enable-gdbmi
6696 *** Changes in GDB-4.18:
6698 * New native configurations
6700 HP-UX 10.20 hppa*-*-hpux10.20
6701 HP-UX 11.x hppa*-*-hpux11.0*
6702 M68K GNU/Linux m68*-*-linux*
6706 Fujitsu FR30 fr30-*-elf*
6707 Intel StrongARM strongarm-*-*
6708 Mitsubishi D30V d30v-*-*
6710 * OBSOLETE configurations
6712 Gould PowerNode, NP1 np1-*-*, pn-*-*
6714 Configurations that have been declared obsolete will be commented out,
6715 but the code will be left in place. If there is no activity to revive
6716 these configurations before the next release of GDB, the sources will
6717 be permanently REMOVED.
6721 As a compatibility experiment, GDB's source files buildsym.h and
6722 buildsym.c have been converted to pure standard C, no longer
6723 containing any K&R compatibility code. We believe that all systems in
6724 use today either come with a standard C compiler, or have a GCC port
6725 available. If this is not true, please report the affected
6726 configuration to bug-gdb@gnu.org immediately. See the README file for
6727 information about getting a standard C compiler if you don't have one
6732 GDB now uses readline 2.2.
6734 * set extension-language
6736 You can now control the mapping between filename extensions and source
6737 languages by using the `set extension-language' command. For instance,
6738 you can ask GDB to treat .c files as C++ by saying
6739 set extension-language .c c++
6740 The command `info extensions' lists all of the recognized extensions
6741 and their associated languages.
6743 * Setting processor type for PowerPC and RS/6000
6745 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6746 you can use the `set processor' command to specify what variant of the
6747 PowerPC family you are debugging. The command
6751 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6752 following PowerPC and RS6000 variants:
6754 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6755 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6757 403GC IBM PowerPC 403GC
6758 505 Motorola PowerPC 505
6759 860 Motorola PowerPC 860 or 850
6760 601 Motorola PowerPC 601
6761 602 Motorola PowerPC 602
6762 603 Motorola/IBM PowerPC 603 or 603e
6763 604 Motorola PowerPC 604 or 604e
6764 750 Motorola/IBM PowerPC 750 or 750
6766 At the moment, this command just tells GDB what to name the
6767 special-purpose processor registers. Since almost all the affected
6768 registers are inaccessible to user-level programs, this command is
6769 only useful for remote debugging in its present form.
6773 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6774 more extensive support for HP-UX. Added features include shared
6775 library support, kernel threads and hardware watchpoints for 11.00,
6776 support for HP's ANSI C and C++ compilers, and a compatibility mode
6777 for xdb and dbx commands.
6781 HP's donation includes the new concept of catchpoints, which is a
6782 generalization of the old catch command. On HP-UX, it is now possible
6783 to catch exec, fork, and vfork, as well as library loading.
6785 This means that the existing catch command has changed; its first
6786 argument now specifies the type of catch to be set up. See the
6787 output of "help catch" for a list of catchpoint types.
6789 * Debugging across forks
6791 On HP-UX, you can choose which process to debug when a fork() happens
6796 HP has donated a curses-based terminal user interface (TUI). To get
6797 it, build with --enable-tui. Although this can be enabled for any
6798 configuration, at present it only works for native HP debugging.
6800 * GDB remote protocol additions
6802 A new protocol packet 'X' that writes binary data is now available.
6803 Default behavior is to try 'X', then drop back to 'M' if the stub
6804 fails to respond. The settable variable `remotebinarydownload'
6805 allows explicit control over the use of 'X'.
6807 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6808 full 64-bit address. The command
6810 set remoteaddresssize 32
6812 can be used to revert to the old behaviour. For existing remote stubs
6813 the change should not be noticed, as the additional address information
6816 In order to assist in debugging stubs, you may use the maintenance
6817 command `packet' to send any text string to the stub. For instance,
6819 maint packet heythere
6821 sends the packet "$heythere#<checksum>". Note that it is very easy to
6822 disrupt a debugging session by sending the wrong packet at the wrong
6825 The compare-sections command allows you to compare section data on the
6826 target to what is in the executable file without uploading or
6827 downloading, by comparing CRC checksums.
6829 * Tracing can collect general expressions
6831 You may now collect general expressions at tracepoints. This requires
6832 further additions to the target-side stub; see tracepoint.c and
6833 doc/agentexpr.texi for further details.
6835 * mask-address variable for Mips
6837 For Mips targets, you may control the zeroing of the upper 32 bits of
6838 a 64-bit address by entering `set mask-address on'. This is mainly
6839 of interest to users of embedded R4xxx and R5xxx processors.
6841 * Higher serial baud rates
6843 GDB's serial code now allows you to specify baud rates 57600, 115200,
6844 230400, and 460800 baud. (Note that your host system may not be able
6845 to achieve all of these rates.)
6849 The i960 configuration now includes an initial implementation of a
6850 builtin simulator, contributed by Jim Wilson.
6853 *** Changes in GDB-4.17:
6855 * New native configurations
6857 Alpha GNU/Linux alpha*-*-linux*
6858 Unixware 2.x i[3456]86-unixware2*
6859 Irix 6.x mips*-sgi-irix6*
6860 PowerPC GNU/Linux powerpc-*-linux*
6861 PowerPC Solaris powerpcle-*-solaris*
6862 Sparc GNU/Linux sparc-*-linux*
6863 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6867 Argonaut Risc Chip (ARC) arc-*-*
6868 Hitachi H8/300S h8300*-*-*
6869 Matsushita MN10200 w/simulator mn10200-*-*
6870 Matsushita MN10300 w/simulator mn10300-*-*
6871 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6872 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6873 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6874 Mitsubishi D10V w/simulator d10v-*-*
6875 Mitsubishi M32R/D w/simulator m32r-*-elf*
6876 Tsqware Sparclet sparclet-*-*
6877 NEC V850 w/simulator v850-*-*
6879 * New debugging protocols
6881 ARM with RDI protocol arm*-*-*
6882 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6883 DDB and LSI variants of PMON protocol mips*-*-*
6884 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6885 PowerPC with SDS protocol powerpc{,le}-*-eabi
6886 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6890 All configurations can now understand and use the DWARF 2 debugging
6891 format. The choice is automatic, if the symbol file contains DWARF 2
6896 GDB now includes basic Java language support. This support is
6897 only useful with Java compilers that produce native machine code.
6899 * solib-absolute-prefix and solib-search-path
6901 For SunOS and SVR4 shared libraries, you may now set the prefix for
6902 loading absolute shared library symbol files, and the search path for
6903 locating non-absolute shared library symbol files.
6905 * Live range splitting
6907 GDB can now effectively debug code for which GCC has performed live
6908 range splitting as part of its optimization. See gdb/doc/LRS for
6909 more details on the expected format of the stabs information.
6913 GDB's support for the GNU Hurd, including thread debugging, has been
6914 updated to work with current versions of the Hurd.
6918 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6919 instruction set. ARM GDB automatically detects when Thumb
6920 instructions are in use, and adjusts disassembly and backtracing
6925 GDB's MIPS target configurations now handle the MIP16 16-bit
6930 GDB now includes support for overlays; if an executable has been
6931 linked such that multiple sections are based at the same address, GDB
6932 will decide which section to use for symbolic info. You can choose to
6933 control the decision manually, using overlay commands, or implement
6934 additional target-side support and use "overlay load-target" to bring
6935 in the overlay mapping. Do "help overlay" for more detail.
6939 The command "info symbol <address>" displays information about
6940 the symbol at the specified address.
6944 The standard remote protocol now includes an extension that allows
6945 asynchronous collection and display of trace data. This requires
6946 extensive support in the target-side debugging stub. Tracing mode
6947 includes a new interaction mode in GDB and new commands: see the
6948 file tracepoint.c for more details.
6952 Configurations for embedded MIPS now include a simulator contributed
6953 by Cygnus Solutions. The simulator supports the instruction sets
6954 of most MIPS variants.
6958 Sparc configurations may now include the ERC32 simulator contributed
6959 by the European Space Agency. The simulator is not built into
6960 Sparc targets by default; configure with --enable-sim to include it.
6964 For target configurations that may include multiple variants of a
6965 basic architecture (such as MIPS and SH), you may now set the
6966 architecture explicitly. "set arch" sets, "info arch" lists
6967 the possible architectures.
6969 *** Changes in GDB-4.16:
6971 * New native configurations
6973 Windows 95, x86 Windows NT i[345]86-*-cygwin32
6974 M68K NetBSD m68k-*-netbsd*
6975 PowerPC AIX 4.x powerpc-*-aix*
6976 PowerPC MacOS powerpc-*-macos*
6977 PowerPC Windows NT powerpcle-*-cygwin32
6978 RS/6000 AIX 4.x rs6000-*-aix4*
6982 ARM with RDP protocol arm-*-*
6983 I960 with MON960 i960-*-coff
6984 MIPS VxWorks mips*-*-vxworks*
6985 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
6986 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
6988 Matra Sparclet sparclet-*-*
6992 The powerpc-eabi configuration now includes the PSIM simulator,
6993 contributed by Andrew Cagney, with assistance from Mike Meissner.
6994 PSIM is a very elaborate model of the PowerPC, including not only
6995 basic instruction set execution, but also details of execution unit
6996 performance and I/O hardware. See sim/ppc/README for more details.
7000 GDB now works with Solaris 2.5.
7002 * Windows 95/NT native
7004 GDB will now work as a native debugger on Windows 95 and Windows NT.
7005 To build it from source, you must use the "gnu-win32" environment,
7006 which uses a DLL to emulate enough of Unix to run the GNU tools.
7007 Further information, binaries, and sources are available at
7008 ftp.cygnus.com, under pub/gnu-win32.
7010 * dont-repeat command
7012 If a user-defined command includes the command `dont-repeat', then the
7013 command will not be repeated if the user just types return. This is
7014 useful if the command is time-consuming to run, so that accidental
7015 extra keystrokes don't run the same command many times.
7017 * Send break instead of ^C
7019 The standard remote protocol now includes an option to send a break
7020 rather than a ^C to the target in order to interrupt it. By default,
7021 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7023 * Remote protocol timeout
7025 The standard remote protocol includes a new variable `remotetimeout'
7026 that allows you to set the number of seconds before GDB gives up trying
7027 to read from the target. The default value is 2.
7029 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7031 By default GDB will automatically keep track of objects as they are
7032 loaded and unloaded by the dynamic linker. By using the command `set
7033 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7034 when shared library events occur, thus allowing you to set breakpoints
7035 in shared libraries which are explicitly loaded by the inferior.
7037 Note this feature does not work on hpux8. On hpux9 you must link
7038 /usr/lib/end.o into your program. This feature should work
7039 automatically on hpux10.
7041 * Irix 5.x hardware watchpoint support
7043 Irix 5 configurations now support the use of hardware watchpoints.
7045 * Mips protocol "SYN garbage limit"
7047 When debugging a Mips target using the `target mips' protocol, you
7048 may set the number of characters that GDB will ignore by setting
7049 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7050 every character. The default value is 1050.
7052 * Recording and replaying remote debug sessions
7054 If you set `remotelogfile' to the name of a file, gdb will write to it
7055 a recording of a remote debug session. This recording may then be
7056 replayed back to gdb using "gdbreplay". See gdbserver/README for
7057 details. This is useful when you have a problem with GDB while doing
7058 remote debugging; you can make a recording of the session and send it
7059 to someone else, who can then recreate the problem.
7061 * Speedups for remote debugging
7063 GDB includes speedups for downloading and stepping MIPS systems using
7064 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7065 and more efficient S-record downloading.
7067 * Memory use reductions and statistics collection
7069 GDB now uses less memory and reports statistics about memory usage.
7070 Try the `maint print statistics' command, for example.
7072 *** Changes in GDB-4.15:
7074 * Psymtabs for XCOFF
7076 The symbol reader for AIX GDB now uses partial symbol tables. This
7077 can greatly improve startup time, especially for large executables.
7079 * Remote targets use caching
7081 Remote targets now use a data cache to speed up communication with the
7082 remote side. The data cache could lead to incorrect results because
7083 it doesn't know about volatile variables, thus making it impossible to
7084 debug targets which use memory mapped I/O devices. `set remotecache
7085 off' turns the data cache off.
7087 * Remote targets may have threads
7089 The standard remote protocol now includes support for multiple threads
7090 in the target system, using new protocol commands 'H' and 'T'. See
7091 gdb/remote.c for details.
7095 If GDB is configured with `--enable-netrom', then it will include
7096 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7097 acts as though it is a bank of ROM on the target board, but you can
7098 write into it over the network. GDB's support consists only of
7099 support for fast loading into the emulated ROM; to debug, you must use
7100 another protocol, such as standard remote protocol. The usual
7101 sequence is something like
7103 target nrom <netrom-hostname>
7105 target remote <netrom-hostname>:1235
7109 GDB now includes support for the Apple Macintosh, as a host only. It
7110 may be run as either an MPW tool or as a standalone application, and
7111 it can debug through the serial port. All the usual GDB commands are
7112 available, but to the target command, you must supply "serial" as the
7113 device type instead of "/dev/ttyXX". See mpw-README in the main
7114 directory for more information on how to build. The MPW configuration
7115 scripts */mpw-config.in support only a few targets, and only the
7116 mips-idt-ecoff target has been tested.
7120 GDB configuration now uses autoconf. This is not user-visible,
7121 but does simplify configuration and building.
7125 GDB now supports hpux10.
7127 *** Changes in GDB-4.14:
7129 * New native configurations
7131 x86 FreeBSD i[345]86-*-freebsd
7132 x86 NetBSD i[345]86-*-netbsd
7133 NS32k NetBSD ns32k-*-netbsd
7134 Sparc NetBSD sparc-*-netbsd
7138 A29K VxWorks a29k-*-vxworks
7139 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7140 CPU32 EST-300 emulator m68*-*-est*
7141 PowerPC ELF powerpc-*-elf
7144 * Alpha OSF/1 support for procfs
7146 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7147 possible to attach to running processes. As the mounting of the /proc
7148 filesystem is optional on the Alpha, GDB automatically determines
7149 the availability of /proc during startup. This can lead to problems
7150 if /proc is unmounted after GDB has been started.
7152 * Arguments to user-defined commands
7154 User commands may accept up to 10 arguments separated by whitespace.
7155 Arguments are accessed within the user command via $arg0..$arg9. A
7158 print $arg0 + $arg1 + $arg2
7160 To execute the command use:
7163 Defines the command "adder" which prints the sum of its three arguments.
7164 Note the arguments are text substitutions, so they may reference variables,
7165 use complex expressions, or even perform inferior function calls.
7167 * New `if' and `while' commands
7169 This makes it possible to write more sophisticated user-defined
7170 commands. Both commands take a single argument, which is the
7171 expression to evaluate, and must be followed by the commands to
7172 execute, one per line, if the expression is nonzero, the list being
7173 terminated by the word `end'. The `if' command list may include an
7174 `else' word, which causes the following commands to be executed only
7175 if the expression is zero.
7177 * Fortran source language mode
7179 GDB now includes partial support for Fortran 77. It will recognize
7180 Fortran programs and can evaluate a subset of Fortran expressions, but
7181 variables and functions may not be handled correctly. GDB will work
7182 with G77, but does not yet know much about symbols emitted by other
7185 * Better HPUX support
7187 Most debugging facilities now work on dynamic executables for HPPAs
7188 running hpux9 or later. You can attach to running dynamically linked
7189 processes, but by default the dynamic libraries will be read-only, so
7190 for instance you won't be able to put breakpoints in them. To change
7191 that behavior do the following before running the program:
7197 This will cause the libraries to be mapped private and read-write.
7198 To revert to the normal behavior, do this:
7204 You cannot set breakpoints or examine data in the library until after
7205 the library is loaded if the function/data symbols do not have
7208 GDB can now also read debug symbols produced by the HP C compiler on
7209 HPPAs (sorry, no C++, Fortran or 68k support).
7211 * Target byte order now dynamically selectable
7213 You can choose which byte order to use with a target system, via the
7214 commands "set endian big" and "set endian little", and you can see the
7215 current setting by using "show endian". You can also give the command
7216 "set endian auto", in which case GDB will use the byte order
7217 associated with the executable. Currently, only embedded MIPS
7218 configurations support dynamic selection of target byte order.
7220 * New DOS host serial code
7222 This version uses DPMI interrupts to handle buffered I/O, so you
7223 no longer need to run asynctsr when debugging boards connected to
7226 *** Changes in GDB-4.13:
7228 * New "complete" command
7230 This lists all the possible completions for the rest of the line, if it
7231 were to be given as a command itself. This is intended for use by emacs.
7233 * Trailing space optional in prompt
7235 "set prompt" no longer adds a space for you after the prompt you set. This
7236 allows you to set a prompt which ends in a space or one that does not.
7238 * Breakpoint hit counts
7240 "info break" now displays a count of the number of times the breakpoint
7241 has been hit. This is especially useful in conjunction with "ignore"; you
7242 can ignore a large number of breakpoint hits, look at the breakpoint info
7243 to see how many times the breakpoint was hit, then run again, ignoring one
7244 less than that number, and this will get you quickly to the last hit of
7247 * Ability to stop printing at NULL character
7249 "set print null-stop" will cause GDB to stop printing the characters of
7250 an array when the first NULL is encountered. This is useful when large
7251 arrays actually contain only short strings.
7253 * Shared library breakpoints
7255 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7256 breakpoints in shared libraries before the executable is run.
7258 * Hardware watchpoints
7260 There is a new hardware breakpoint for the watch command for sparclite
7261 targets. See gdb/sparclite/hw_breakpoint.note.
7263 Hardware watchpoints are also now supported under GNU/Linux.
7267 Annotations have been added. These are for use with graphical interfaces,
7268 and are still experimental. Currently only gdba.el uses these.
7270 * Improved Irix 5 support
7272 GDB now works properly with Irix 5.2.
7274 * Improved HPPA support
7276 GDB now works properly with the latest GCC and GAS.
7278 * New native configurations
7280 Sequent PTX4 i[34]86-sequent-ptx4
7281 HPPA running OSF/1 hppa*-*-osf*
7282 Atari TT running SVR4 m68*-*-sysv4*
7283 RS/6000 LynxOS rs6000-*-lynxos*
7287 OS/9000 i[34]86-*-os9k
7288 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7291 * Hitachi SH7000 and E7000-PC ICE support
7293 There is now support for communicating with the Hitachi E7000-PC ICE.
7294 This is available automatically when GDB is configured for the SH.
7298 As usual, a variety of small fixes and improvements, both generic
7299 and configuration-specific. See the ChangeLog for more detail.
7301 *** Changes in GDB-4.12:
7303 * Irix 5 is now supported
7307 GDB-4.12 on the HPPA has a number of changes which make it unable
7308 to debug the output from the currently released versions of GCC and
7309 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7310 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7311 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7314 *** Changes in GDB-4.11:
7316 * User visible changes:
7320 The "set remotedebug" option is now consistent between the mips remote
7321 target, remote targets using the gdb-specific protocol, UDI (AMD's
7322 debug protocol for the 29k) and the 88k bug monitor. It is now an
7323 integer specifying a debug level (normally 0 or 1, but 2 means more
7324 debugging info for the mips target).
7326 * DEC Alpha native support
7328 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7329 debug info, but GDB works fairly well with the DEC compiler and should
7330 work with a future GCC release. See the README file for a few
7331 Alpha-specific notes.
7333 * Preliminary thread implementation
7335 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7337 * LynxOS native and target support for 386
7339 This release has been hosted on LynxOS 2.2, and also can be configured
7340 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7343 * Improvements in C++ mangling/demangling.
7345 This release has much better g++ debugging, specifically in name
7346 mangling/demangling, virtual function calls, print virtual table,
7347 call methods, ...etc.
7349 *** Changes in GDB-4.10:
7351 * User visible changes:
7353 Remote debugging using the GDB-specific (`target remote') protocol now
7354 supports the `load' command. This is only useful if you have some
7355 other way of getting the stub to the target system, and you can put it
7356 somewhere in memory where it won't get clobbered by the download.
7358 Filename completion now works.
7360 When run under emacs mode, the "info line" command now causes the
7361 arrow to point to the line specified. Also, "info line" prints
7362 addresses in symbolic form (as well as hex).
7364 All vxworks based targets now support a user settable option, called
7365 vxworks-timeout. This option represents the number of seconds gdb
7366 should wait for responses to rpc's. You might want to use this if
7367 your vxworks target is, perhaps, a slow software simulator or happens
7368 to be on the far side of a thin network line.
7372 This release contains support for using a DEC alpha as a GDB host for
7373 cross debugging. Native alpha debugging is not supported yet.
7376 *** Changes in GDB-4.9:
7380 This is the first GDB release which is accompanied by a matching testsuite.
7381 The testsuite requires installation of dejagnu, which should be available
7382 via ftp from most sites that carry GNU software.
7386 'Cfront' style demangling has had its name changed to 'ARM' style, to
7387 emphasize that it was written from the specifications in the C++ Annotated
7388 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7389 disclaimers, it still generated too much confusion with users attempting to
7390 use gdb with AT&T cfront.
7394 GDB now uses a standard remote interface to a simulator library.
7395 So far, the library contains simulators for the Zilog Z8001/2, the
7396 Hitachi H8/300, H8/500 and Super-H.
7398 * New targets supported
7400 H8/300 simulator h8300-hitachi-hms or h8300hms
7401 H8/500 simulator h8500-hitachi-hms or h8500hms
7402 SH simulator sh-hitachi-hms or sh
7403 Z8000 simulator z8k-zilog-none or z8ksim
7404 IDT MIPS board over serial line mips-idt-ecoff
7406 Cross-debugging to GO32 targets is supported. It requires a custom
7407 version of the i386-stub.c module which is integrated with the
7408 GO32 memory extender.
7410 * New remote protocols
7412 MIPS remote debugging protocol.
7414 * New source languages supported
7416 This version includes preliminary support for Chill, a Pascal like language
7417 used by telecommunications companies. Chill support is also being integrated
7418 into the GNU compiler, but we don't know when it will be publically available.
7421 *** Changes in GDB-4.8:
7423 * HP Precision Architecture supported
7425 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7426 version of this support was available as a set of patches from the
7427 University of Utah. GDB does not support debugging of programs
7428 compiled with the HP compiler, because HP will not document their file
7429 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7430 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7432 Many problems in the preliminary version have been fixed.
7434 * Faster and better demangling
7436 We have improved template demangling and fixed numerous bugs in the GNU style
7437 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7438 character types (wchar_t) are now supported. Demangling of each symbol is now
7439 only done once, and is cached when the symbol table for a file is read in.
7440 This results in a small increase in memory usage for C programs, a moderate
7441 increase in memory usage for C++ programs, and a fantastic speedup in
7444 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7445 from the specifications in the Annotated Reference Manual, which AT&T's
7446 compiler does not actually implement.
7448 * G++ multiple inheritance compiler problem
7450 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7451 inheritance lattices was reworked to properly discover ambiguities. We
7452 recently found an example which causes this new algorithm to fail in a
7453 very subtle way, producing bad debug information for those classes.
7454 The file 'gcc.patch' (in this directory) can be applied to gcc to
7455 circumvent the problem. A future GCC release will contain a complete
7458 The previous G++ debug info problem (mentioned below for the gdb-4.7
7459 release) is fixed in gcc version 2.3.2.
7461 * Improved configure script
7463 The `configure' script will now attempt to guess your system type if
7464 you don't supply a host system type. The old scheme of supplying a
7465 host system triplet is preferable over using this. All the magic is
7466 done in the new `config.guess' script. Examine it for details.
7468 We have also brought our configure script much more in line with the FSF's
7469 version. It now supports the --with-xxx options. In particular,
7470 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7471 The resulting GDB will not be able to read arbitrary object file formats --
7472 only the format ``expected'' to be used on the configured target system.
7473 We hope to make this the default in a future release.
7475 * Documentation improvements
7477 There's new internal documentation on how to modify GDB, and how to
7478 produce clean changes to the code. We implore people to read it
7479 before submitting changes.
7481 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7482 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7483 `info' files are also provided. To build `info' files from scratch,
7484 you will need the latest `makeinfo' release, which will be available in
7485 a future texinfo-X.Y release.
7487 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7488 We're not sure exactly which versions have this problem, but it has
7489 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7490 or better. If that isn't possible, there is a patch in
7491 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7492 around this problem.
7496 GDB now supports array constants that can be used in expressions typed in by
7497 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7498 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7501 The new directory `gdb/sparclite' contains a program that demonstrates
7502 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7504 * New native hosts supported
7506 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7507 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7509 * New targets supported
7511 AMD 29k family via UDI a29k-amd-udi or udi29k
7513 * New file formats supported
7515 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7516 HPUX core files, and SCO 3.2v2 core files.
7520 Attaching to processes now works again; thanks for the many bug reports.
7522 We have also stomped on a bunch of core dumps caused by
7523 printf_filtered("%s") problems.
7525 We eliminated a copyright problem on the rpc and ptrace header files
7526 for VxWorks, which was discovered at the last minute during the 4.7
7527 release. You should now be able to build a VxWorks GDB.
7529 You can now interrupt gdb while an attached process is running. This
7530 will cause the attached process to stop, and give control back to GDB.
7532 We fixed problems caused by using too many file descriptors
7533 for reading symbols from object files and libraries. This was
7534 especially a problem for programs that used many (~100) shared
7537 The `step' command now only enters a subroutine if there is line number
7538 information for the subroutine. Otherwise it acts like the `next'
7539 command. Previously, `step' would enter subroutines if there was
7540 any debugging information about the routine. This avoids problems
7541 when using `cc -g1' on MIPS machines.
7543 * Internal improvements
7545 GDB's internal interfaces have been improved to make it easier to support
7546 debugging of multiple languages in the future.
7548 GDB now uses a common structure for symbol information internally.
7549 Minimal symbols (derived from linkage symbols in object files), partial
7550 symbols (from a quick scan of debug information), and full symbols
7551 contain a common subset of information, making it easier to write
7552 shared code that handles any of them.
7554 * New command line options
7556 We now accept --silent as an alias for --quiet.
7560 The memory-mapped-malloc library is now licensed under the GNU Library
7561 General Public License.
7563 *** Changes in GDB-4.7:
7565 * Host/native/target split
7567 GDB has had some major internal surgery to untangle the support for
7568 hosts and remote targets. Now, when you configure GDB for a remote
7569 target, it will no longer load in all of the support for debugging
7570 local programs on the host. When fully completed and tested, this will
7571 ensure that arbitrary host/target combinations are possible.
7573 The primary conceptual shift is to separate the non-portable code in
7574 GDB into three categories. Host specific code is required any time GDB
7575 is compiled on that host, regardless of the target. Target specific
7576 code relates to the peculiarities of the target, but can be compiled on
7577 any host. Native specific code is everything else: it can only be
7578 built when the host and target are the same system. Child process
7579 handling and core file support are two common `native' examples.
7581 GDB's use of /proc for controlling Unix child processes is now cleaner.
7582 It has been split out into a single module under the `target_ops' vector,
7583 plus two native-dependent functions for each system that uses /proc.
7585 * New hosts supported
7587 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7588 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7589 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7591 * New targets supported
7593 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7594 68030 and CPU32 m68030-*-*, m68332-*-*
7596 * New native hosts supported
7598 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7599 (386bsd is not well tested yet)
7600 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7602 * New file formats supported
7604 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7605 supports reading of `a.out.adobe' object files, which are an a.out
7606 format extended with minimal information about multiple sections.
7610 `show copying' is the same as the old `info copying'.
7611 `show warranty' is the same as `info warrantee'.
7612 These were renamed for consistency. The old commands continue to work.
7614 `info handle' is a new alias for `info signals'.
7616 You can now define pre-command hooks, which attach arbitrary command
7617 scripts to any command. The commands in the hook will be executed
7618 prior to the user's command. You can also create a hook which will be
7619 executed whenever the program stops. See gdb.texinfo.
7623 We now deal with Cfront style name mangling, and can even extract type
7624 info from mangled symbols. GDB can automatically figure out which
7625 symbol mangling style your C++ compiler uses.
7627 Calling of methods and virtual functions has been improved as well.
7631 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7632 fixed. This was due to mishandling of the extra N_SO stabs output
7635 We also finally got Ultrix 4.2 running in house, and fixed core file
7636 support, with help from a dozen people on the net.
7638 John M. Farrell discovered that the reason that single-stepping was so
7639 slow on all of the Mips based platforms (primarily SGI and DEC) was
7640 that we were trying to demangle and lookup a symbol used for internal
7641 purposes on every instruction that was being stepped through. Changing
7642 the name of that symbol so that it couldn't be mistaken for a C++
7643 mangled symbol sped things up a great deal.
7645 Rich Pixley sped up symbol lookups in general by getting much smarter
7646 about when C++ symbol mangling is necessary. This should make symbol
7647 completion (TAB on the command line) much faster. It's not as fast as
7648 we'd like, but it's significantly faster than gdb-4.6.
7652 A new user controllable variable 'call_scratch_address' can
7653 specify the location of a scratch area to be used when GDB
7654 calls a function in the target. This is necessary because the
7655 usual method of putting the scratch area on the stack does not work
7656 in systems that have separate instruction and data spaces.
7658 We integrated changes to support the 29k UDI (Universal Debugger
7659 Interface), but discovered at the last minute that we didn't have all
7660 of the appropriate copyright paperwork. We are working with AMD to
7661 resolve this, and hope to have it available soon.
7665 We have sped up the remote serial line protocol, especially for targets
7666 with lots of registers. It now supports a new `expedited status' ('T')
7667 message which can be used in place of the existing 'S' status message.
7668 This allows the remote stub to send only the registers that GDB
7669 needs to make a quick decision about single-stepping or conditional
7670 breakpoints, eliminating the need to fetch the entire register set for
7671 each instruction being stepped through.
7673 The GDB remote serial protocol now implements a write-through cache for
7674 registers, only re-reading the registers if the target has run.
7676 There is also a new remote serial stub for SPARC processors. You can
7677 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7678 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7679 processor with a serial port.
7683 Configure.in files have become much easier to read and modify. A new
7684 `table driven' format makes it more obvious what configurations are
7685 supported, and what files each one uses.
7689 There is a new opcodes library which will eventually contain all of the
7690 disassembly routines and opcode tables. At present, it only contains
7691 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7692 disassembler (binutils/objdump) to share these routines.
7694 The libiberty library is now copylefted under the GNU Library General
7695 Public License. This allows more liberal use, and was done so libg++
7696 can use it. This makes no difference to GDB, since the Library License
7697 grants all the rights from the General Public License.
7701 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7702 reference to the stabs symbol info used by the debugger. It is (as far
7703 as we know) the only published document on this fascinating topic. We
7704 encourage you to read it, compare it to the stabs information on your
7705 system, and send improvements on the document in general (to
7706 bug-gdb@prep.ai.mit.edu).
7708 And, of course, many bugs have been fixed.
7711 *** Changes in GDB-4.6:
7713 * Better support for C++ function names
7715 GDB now accepts as input the "demangled form" of C++ overloaded function
7716 names and member function names, and can do command completion on such names
7717 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7718 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7719 Make use of command completion, it is your friend.
7721 GDB also now accepts a variety of C++ mangled symbol formats. They are
7722 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7723 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7724 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7725 for the list of formats.
7727 * G++ symbol mangling problem
7729 Recent versions of gcc have a bug in how they emit debugging information for
7730 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7731 directory) can be applied to gcc to fix the problem. Alternatively, if you
7732 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7733 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7734 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7737 * New 'maintenance' command
7739 All of the commands related to hacking GDB internals have been moved out of
7740 the main command set, and now live behind the 'maintenance' command. This
7741 can also be abbreviated as 'mt'. The following changes were made:
7743 dump-me -> maintenance dump-me
7744 info all-breakpoints -> maintenance info breakpoints
7745 printmsyms -> maintenance print msyms
7746 printobjfiles -> maintenance print objfiles
7747 printpsyms -> maintenance print psymbols
7748 printsyms -> maintenance print symbols
7750 The following commands are new:
7752 maintenance demangle Call internal GDB demangler routine to
7753 demangle a C++ link name and prints the result.
7754 maintenance print type Print a type chain for a given symbol
7756 * Change to .gdbinit file processing
7758 We now read the $HOME/.gdbinit file before processing the argv arguments
7759 (e.g. reading symbol files or core files). This allows global parameters to
7760 be set, which will apply during the symbol reading. The ./.gdbinit is still
7761 read after argv processing.
7763 * New hosts supported
7765 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7767 GNU/Linux support i386-unknown-linux or linux
7769 We are also including code to support the HP/PA running BSD and HPUX. This
7770 is almost guaranteed not to work, as we didn't have time to test or build it
7771 for this release. We are including it so that the more adventurous (or
7772 masochistic) of you can play with it. We also had major problems with the
7773 fact that the compiler that we got from HP doesn't support the -g option.
7776 * New targets supported
7778 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7780 * More smarts about finding #include files
7782 GDB now remembers the compilation directory for all include files, and for
7783 all files from which C is generated (like yacc and lex sources). This
7784 greatly improves GDB's ability to find yacc/lex sources, and include files,
7785 especially if you are debugging your program from a directory different from
7786 the one that contains your sources.
7788 We also fixed a bug which caused difficulty with listing and setting
7789 breakpoints in include files which contain C code. (In the past, you had to
7790 try twice in order to list an include file that you hadn't looked at before.)
7792 * Interesting infernals change
7794 GDB now deals with arbitrary numbers of sections, where the symbols for each
7795 section must be relocated relative to that section's landing place in the
7796 target's address space. This work was needed to support ELF with embedded
7797 stabs used by Solaris-2.0.
7799 * Bug fixes (of course!)
7801 There have been loads of fixes for the following things:
7802 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7803 i960, stabs, DOS(GO32), procfs, etc...
7805 See the ChangeLog for details.
7807 *** Changes in GDB-4.5:
7809 * New machines supported (host and target)
7811 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7813 SGI Irix-4.x mips-sgi-irix4 or iris4
7815 * New malloc package
7817 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7818 Mmalloc is capable of handling multiple heaps of memory. It is also
7819 capable of saving a heap to a file, and then mapping it back in later.
7820 This can be used to greatly speedup the startup of GDB by using a
7821 pre-parsed symbol table which lives in a mmalloc managed heap. For
7822 more details, please read mmalloc/mmalloc.texi.
7826 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7827 'help info proc' for details.
7829 * MIPS ecoff symbol table format
7831 The code that reads MIPS symbol table format is now supported on all hosts.
7832 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7835 * File name changes for MS-DOS
7837 Many files in the config directories have been renamed to make it easier to
7838 support GDB on MS-DOSe systems (which have very restrictive file name
7839 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7840 environment) is close to working but has some remaining problems. Note
7841 that debugging of DOS programs is not supported, due to limitations
7842 in the ``operating system'', but it can be used to host cross-debugging.
7844 * Cross byte order fixes
7846 Many fixes have been made to support cross debugging of Sparc and MIPS
7847 targets from hosts whose byte order differs.
7849 * New -mapped and -readnow options
7851 If memory-mapped files are available on your system through the 'mmap'
7852 system call, you can use the -mapped option on the `file' or
7853 `symbol-file' commands to cause GDB to write the symbols from your
7854 program into a reusable file. If the program you are debugging is
7855 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7856 Future GDB debugging sessions will notice the presence of this file,
7857 and will quickly map in symbol information from it, rather than reading
7858 the symbol table from the executable program. Using the '-mapped'
7859 option in a GDB `file' or `symbol-file' command has the same effect as
7860 starting GDB with the '-mapped' command-line option.
7862 You can cause GDB to read the entire symbol table immediately by using
7863 the '-readnow' option with any of the commands that load symbol table
7864 information (or on the GDB command line). This makes the command
7865 slower, but makes future operations faster.
7867 The -mapped and -readnow options are typically combined in order to
7868 build a `fred.syms' file that contains complete symbol information.
7869 A simple GDB invocation to do nothing but build a `.syms' file for future
7872 gdb -batch -nx -mapped -readnow programname
7874 The `.syms' file is specific to the host machine on which GDB is run.
7875 It holds an exact image of GDB's internal symbol table. It cannot be
7876 shared across multiple host platforms.
7878 * longjmp() handling
7880 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7881 siglongjmp() without losing control. This feature has not yet been ported to
7882 all systems. It currently works on many 386 platforms, all MIPS-based
7883 platforms (SGI, DECstation, etc), and Sun3/4.
7887 Preliminary work has been put in to support the new Solaris OS from Sun. At
7888 this time, it can control and debug processes, but it is not capable of
7893 As always, many many bug fixes. The major areas were with g++, and mipsread.
7894 People using the MIPS-based platforms should experience fewer mysterious
7895 crashes and trashed symbol tables.
7897 *** Changes in GDB-4.4:
7899 * New machines supported (host and target)
7901 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7903 BSD Reno on Vax vax-dec-bsd
7904 Ultrix on Vax vax-dec-ultrix
7906 * New machines supported (target)
7908 AMD 29000 embedded, using EBMON a29k-none-none
7912 GDB continues to improve its handling of C++. `References' work better.
7913 The demangler has also been improved, and now deals with symbols mangled as
7914 per the Annotated C++ Reference Guide.
7916 GDB also now handles `stabs' symbol information embedded in MIPS
7917 `ecoff' symbol tables. Since the ecoff format was not easily
7918 extensible to handle new languages such as C++, this appeared to be a
7919 good way to put C++ debugging info into MIPS binaries. This option
7920 will be supported in the GNU C compiler, version 2, when it is
7923 * New features for SVR4
7925 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7926 shared libraries. Debugging dynamically linked programs should present
7927 only minor differences from debugging statically linked programs.
7929 The `info proc' command will print out information about any process
7930 on an SVR4 system (including the one you are debugging). At the moment,
7931 it prints the address mappings of the process.
7933 If you bring up GDB on another SVR4 system, please send mail to
7934 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7936 * Better dynamic linking support in SunOS
7938 Reading symbols from shared libraries which contain debugging symbols
7939 now works properly. However, there remain issues such as automatic
7940 skipping of `transfer vector' code during function calls, which
7941 make it harder to debug code in a shared library, than to debug the
7942 same code linked statically.
7946 GDB is now using the latest `getopt' routines from the FSF. This
7947 version accepts the -- prefix for options with long names. GDB will
7948 continue to accept the old forms (-option and +option) as well.
7949 Various single letter abbreviations for options have been explicity
7950 added to the option table so that they won't get overshadowed in the
7951 future by other options that begin with the same letter.
7955 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7956 Many assorted bugs have been handled. Many more remain to be handled.
7957 See the various ChangeLog files (primarily in gdb and bfd) for details.
7960 *** Changes in GDB-4.3:
7962 * New machines supported (host and target)
7964 Amiga 3000 running Amix m68k-cbm-svr4 or amix
7965 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
7966 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7968 * Almost SCO Unix support
7970 We had hoped to support:
7971 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7972 (except for core file support), but we discovered very late in the release
7973 that it has problems with process groups that render gdb unusable. Sorry
7974 about that. I encourage people to fix it and post the fixes.
7976 * Preliminary ELF and DWARF support
7978 GDB can read ELF object files on System V Release 4, and can handle
7979 debugging records for C, in DWARF format, in ELF files. This support
7980 is preliminary. If you bring up GDB on another SVR4 system, please
7981 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
7986 GDB now uses the latest `readline' library. One user-visible change
7987 is that two tabs will list possible command completions, which previously
7988 required typing M-? (meta-question mark, or ESC ?).
7992 The `stepi' bug that many of you noticed has been squashed.
7993 Many bugs in C++ have been handled. Many more remain to be handled.
7994 See the various ChangeLog files (primarily in gdb and bfd) for details.
7996 * State of the MIPS world (in case you wondered):
7998 GDB can understand the symbol tables emitted by the compilers
7999 supplied by most vendors of MIPS-based machines, including DEC. These
8000 symbol tables are in a format that essentially nobody else uses.
8002 Some versions of gcc come with an assembler post-processor called
8003 mips-tfile. This program is required if you want to do source-level
8004 debugging of gcc-compiled programs. I believe FSF does not ship
8005 mips-tfile with gcc version 1, but it will eventually come with gcc
8008 Debugging of g++ output remains a problem. g++ version 1.xx does not
8009 really support it at all. (If you're lucky, you should be able to get
8010 line numbers and stack traces to work, but no parameters or local
8011 variables.) With some work it should be possible to improve the
8014 When gcc version 2 is released, you will have somewhat better luck.
8015 However, even then you will get confusing results for inheritance and
8018 We will eventually provide full debugging of g++ output on
8019 DECstations. This will probably involve some kind of stabs-in-ecoff
8020 encapulation, but the details have not been worked out yet.
8023 *** Changes in GDB-4.2:
8025 * Improved configuration
8027 Only one copy of `configure' exists now, and it is not self-modifying.
8028 Porting BFD is simpler.
8032 The `step' and `next' commands now only stop at the first instruction
8033 of a source line. This prevents the multiple stops that used to occur
8034 in switch statements, for-loops, etc. `Step' continues to stop if a
8035 function that has debugging information is called within the line.
8039 Lots of small bugs fixed. More remain.
8041 * New host supported (not target)
8043 Intel 386 PC clone running Mach i386-none-mach
8046 *** Changes in GDB-4.1:
8048 * Multiple source language support
8050 GDB now has internal scaffolding to handle several source languages.
8051 It determines the type of each source file from its filename extension,
8052 and will switch expression parsing and number formatting to match the
8053 language of the function in the currently selected stack frame.
8054 You can also specifically set the language to be used, with
8055 `set language c' or `set language modula-2'.
8059 GDB now has preliminary support for the GNU Modula-2 compiler,
8060 currently under development at the State University of New York at
8061 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8062 continue through the fall of 1991 and into 1992.
8064 Other Modula-2 compilers are currently not supported, and attempting to
8065 debug programs compiled with them will likely result in an error as the
8066 symbol table is read. Feel free to work on it, though!
8068 There are hooks in GDB for strict type checking and range checking,
8069 in the `Modula-2 philosophy', but they do not currently work.
8073 GDB can now write to executable and core files (e.g. patch
8074 a variable's value). You must turn this switch on, specify
8075 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8076 by assigning a new value to a variable. Modifications take
8079 * Automatic SunOS shared library reading
8081 When you run your program, GDB automatically determines where its
8082 shared libraries (if any) have been loaded, and reads their symbols.
8083 The `share' command is no longer needed. This also works when
8084 examining core files.
8088 You can specify the number of lines that the `list' command shows.
8091 * New machines supported (host and target)
8093 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8094 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8095 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8097 * New hosts supported (not targets)
8099 IBM RT/PC: romp-ibm-aix or rtpc
8101 * New targets supported (not hosts)
8103 AMD 29000 embedded with COFF a29k-none-coff
8104 AMD 29000 embedded with a.out a29k-none-aout
8105 Ultracomputer remote kernel debug a29k-nyu-kern
8107 * New remote interfaces
8113 *** Changes in GDB-4.0:
8117 Wide output is wrapped at good places to make the output more readable.
8119 Gdb now supports cross-debugging from a host machine of one type to a
8120 target machine of another type. Communication with the target system
8121 is over serial lines. The ``target'' command handles connecting to the
8122 remote system; the ``load'' command will download a program into the
8123 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8124 also supports debugging of realtime processes running under VxWorks,
8125 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8126 stub on the target system.
8128 New CPUs supported include the AMD 29000 and Intel 960.
8130 GDB now reads object files and symbol tables via a ``binary file''
8131 library, which allows a single copy of GDB to debug programs of multiple
8132 object file types such as a.out and coff.
8134 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8135 refcard.dvi and refcard.ps are available to format it).
8138 * Control-Variable user interface simplified
8140 All variables that control the operation of the debugger can be set
8141 by the ``set'' command, and displayed by the ``show'' command.
8143 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8144 ``Show prompt'' produces the response:
8145 Gdb's prompt is new-gdb=>.
8147 What follows are the NEW set commands. The command ``help set'' will
8148 print a complete list of old and new set commands. ``help set FOO''
8149 will give a longer description of the variable FOO. ``show'' will show
8150 all of the variable descriptions and their current settings.
8152 confirm on/off: Enables warning questions for operations that are
8153 hard to recover from, e.g. rerunning the program while
8154 it is already running. Default is ON.
8156 editing on/off: Enables EMACS style command line editing
8157 of input. Previous lines can be recalled with
8158 control-P, the current line can be edited with control-B,
8159 you can search for commands with control-R, etc.
8162 history filename NAME: NAME is where the gdb command history
8163 will be stored. The default is .gdb_history,
8164 or the value of the environment variable
8167 history size N: The size, in commands, of the command history. The
8168 default is 256, or the value of the environment variable
8171 history save on/off: If this value is set to ON, the history file will
8172 be saved after exiting gdb. If set to OFF, the
8173 file will not be saved. The default is OFF.
8175 history expansion on/off: If this value is set to ON, then csh-like
8176 history expansion will be performed on
8177 command line input. The default is OFF.
8179 radix N: Sets the default radix for input and output. It can be set
8180 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8181 in the current radix, so "set radix 10" is always a no-op.
8183 height N: This integer value is the number of lines on a page. Default
8184 is 24, the current `stty rows'' setting, or the ``li#''
8185 setting from the termcap entry matching the environment
8188 width N: This integer value is the number of characters on a line.
8189 Default is 80, the current `stty cols'' setting, or the ``co#''
8190 setting from the termcap entry matching the environment
8193 Note: ``set screensize'' is obsolete. Use ``set height'' and
8194 ``set width'' instead.
8196 print address on/off: Print memory addresses in various command displays,
8197 such as stack traces and structure values. Gdb looks
8198 more ``symbolic'' if you turn this off; it looks more
8199 ``machine level'' with it on. Default is ON.
8201 print array on/off: Prettyprint arrays. New convenient format! Default
8204 print demangle on/off: Print C++ symbols in "source" form if on,
8207 print asm-demangle on/off: Same, for assembler level printouts
8210 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8213 * Support for Epoch Environment.
8215 The epoch environment is a version of Emacs v18 with windowing. One
8216 new command, ``inspect'', is identical to ``print'', except that if you
8217 are running in the epoch environment, the value is printed in its own
8221 * Support for Shared Libraries
8223 GDB can now debug programs and core files that use SunOS shared libraries.
8224 Symbols from a shared library cannot be referenced
8225 before the shared library has been linked with the program (this
8226 happens after you type ``run'' and before the function main() is entered).
8227 At any time after this linking (including when examining core files
8228 from dynamically linked programs), gdb reads the symbols from each
8229 shared library when you type the ``sharedlibrary'' command.
8230 It can be abbreviated ``share''.
8232 sharedlibrary REGEXP: Load shared object library symbols for files
8233 matching a unix regular expression. No argument
8234 indicates to load symbols for all shared libraries.
8236 info sharedlibrary: Status of loaded shared libraries.
8241 A watchpoint stops execution of a program whenever the value of an
8242 expression changes. Checking for this slows down execution
8243 tremendously whenever you are in the scope of the expression, but is
8244 quite useful for catching tough ``bit-spreader'' or pointer misuse
8245 problems. Some machines such as the 386 have hardware for doing this
8246 more quickly, and future versions of gdb will use this hardware.
8248 watch EXP: Set a watchpoint (breakpoint) for an expression.
8250 info watchpoints: Information about your watchpoints.
8252 delete N: Deletes watchpoint number N (same as breakpoints).
8253 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8254 enable N: Re-enables watchpoint number N (same as breakpoints).
8257 * C++ multiple inheritance
8259 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8262 * C++ exception handling
8264 Gdb now supports limited C++ exception handling. Besides the existing
8265 ability to breakpoint on an exception handler, gdb can breakpoint on
8266 the raising of an exception (before the stack is peeled back to the
8269 catch FOO: If there is a FOO exception handler in the dynamic scope,
8270 set a breakpoint to catch exceptions which may be raised there.
8271 Multiple exceptions (``catch foo bar baz'') may be caught.
8273 info catch: Lists all exceptions which may be caught in the
8274 current stack frame.
8277 * Minor command changes
8279 The command ``call func (arg, arg, ...)'' now acts like the print
8280 command, except it does not print or save a value if the function's result
8281 is void. This is similar to dbx usage.
8283 The ``up'' and ``down'' commands now always print the frame they end up
8284 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8285 frames without printing.
8287 * New directory command
8289 'dir' now adds directories to the FRONT of the source search path.
8290 The path starts off empty. Source files that contain debug information
8291 about the directory in which they were compiled can be found even
8292 with an empty path; Sun CC and GCC include this information. If GDB can't
8293 find your source file in the current directory, type "dir .".
8295 * Configuring GDB for compilation
8297 For normal use, type ``./configure host''. See README or gdb.texinfo
8300 GDB now handles cross debugging. If you are remotely debugging between
8301 two different machines, type ``./configure host -target=targ''.
8302 Host is the machine where GDB will run; targ is the machine
8303 where the program that you are debugging will run.