1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 11
6 * Improved C++ template support
8 GDB now treats functions/types involving C++ templates like it does function
9 overloads. Users may omit parameter lists to set breakpoints on families of
10 template functions, including types/functions composed of multiple template types:
12 (gdb) break template_func(template_1, int)
14 The above will set breakpoints at every function `template_func' where
15 the first function parameter is any template type named `template_1' and
16 the second function parameter is `int'.
18 TAB completion also gains similar improvements.
20 * The FreeBSD native target now supports async mode.
26 Enable or disable multithreaded symbol loading. This is enabled
27 by default, but passing --disable-threading or --enable-threading=no
28 to configure will disable it.
30 Disabling this can cause a performance penalty when there are a lot of
31 symbols to load, but is useful for debugging purposes.
35 maint set backtrace-on-fatal-signal on|off
36 maint show backtrace-on-fatal-signal
37 This setting is 'on' by default. When 'on' GDB will print a limited
38 backtrace to stderr in the situation where GDB terminates with a
39 fatal signal. This only supported on some platforms where the
40 backtrace and backtrace_symbols_fd functions are available.
42 set source open on|off
44 This setting, which is on by default, controls whether GDB will try
45 to open source code files. Switching this off will stop GDB trying
46 to open and read source code files, which can be useful if the files
47 are located over a slow network connection.
51 These are now deprecated aliases for "set max-value-size" and
52 "show max-value-size".
54 task apply [all | TASK-IDS...] [FLAG]... COMMAND
55 Like "thread apply", but applies COMMAND to Ada tasks.
58 Watchpoints can now be restricted to a specific Ada task.
60 maint set internal-error backtrace on|off
61 maint show internal-error backtrace
62 maint set internal-warning backtrace on|off
63 maint show internal-warning backtrace
64 GDB can now print a backtrace of itself when it encounters either an
65 internal-error, or an internal-warning. This is on by default for
66 internal-error and off by default for internal-warning.
69 Deprecated and replaced by "set logging enabled on|off".
71 set logging enabled on|off
73 These commands set or show whether logging is enabled or disabled.
76 You can now exit GDB by using the new command "exit", in addition to
77 the existing "quit" command.
79 set debug threads on|off
81 Print additional debug messages about thread creation and deletion.
83 set debug linux-nat on|off
85 These new commands replaced the old 'set debug lin-lwp' and 'show
86 debug lin-lwp' respectively. Turning this setting on prints debug
87 messages relating to GDB's handling of native Linux inferiors.
89 maint flush source-cache
90 Flush the contents of the source code cache.
92 maint set gnu-source-highlight enabled on|off
93 maint show gnu-source-highlight enabled
94 Whether GDB should use the GNU Source Highlight library for adding
95 styling to source code. When off, the library will not be used, even
96 when available. When GNU Source Highlight isn't used, or can't add
97 styling to a particular source file, then the Python Pygments
98 library will be used instead.
100 set suppress-cli-notifications (on|off)
101 show suppress-cli-notifications
102 This controls whether printing the notifications is suppressed for CLI.
103 CLI notifications occur when you change the selected context
104 (i.e., the current inferior, thread and/or the frame), or when
105 the program being debugged stops (e.g., because of hitting a
106 breakpoint, completing source-stepping, an interrupt, etc.).
108 set style disassembler enabled on|off
109 show style disassembler enabled
110 If GDB is compiled with Python support, and the Python Pygments
111 package is available, then, when this setting is on, disassembler
112 output will have styling applied.
114 set ada source-charset
115 show ada source-charset
116 Set the character set encoding that is assumed for Ada symbols. Valid
117 values for this follow the values that can be passed to the GNAT
118 compiler via the '-gnati' option. The default is ISO-8859-1.
123 This command can now print a reply, if the reply includes
124 non-printable characters. Any non-printable characters are printed
125 as escaped hex, e.g. \x?? where '??' is replaces with the value of
126 the non-printable character.
129 The clone-inferior command now ensures that the TTY, CMD and ARGS
130 settings are copied from the original inferior to the new one.
131 All modifications to the environment variables done using the 'set
132 environment' or 'unset environment' commands are also copied to the new
135 set debug lin-lwp on|off
137 These commands have been removed from GDB. The new command 'set
138 debug linux-nat' and 'show debug linux-nat' should be used
142 This command now includes information about the width of the tui
143 windows in its output.
145 * GDB's Ada parser now supports an extension for specifying the exact
146 byte contents of a floating-point literal. This can be useful for
147 setting floating-point registers to a precise value without loss of
148 precision. The syntax is an extension of the based literal syntax.
149 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
150 of the floating-point type, and the "f" is the marker for floating
155 GNU/Linux/LoongArch loongarch*-*-linux*
159 ** New function gdb.add_history(), which takes a gdb.Value object
160 and adds the value it represents to GDB's history list. An
161 integer, the index of the new item in the history list, is
164 ** New function gdb.history_count(), which returns the number of
165 values in GDB's value history.
167 ** New gdb.events.gdb_exiting event. This event is called with a
168 gdb.GdbExitingEvent object which has the read-only attribute
169 'exit_code', which contains the value of the GDB exit code. This
170 event is triggered once GDB decides it is going to exit, but
171 before GDB starts to clean up its internal state.
173 ** New function gdb.architecture_names(), which returns a list
174 containing all of the possible Architecture.name() values. Each
177 ** New function gdb.Architecture.integer_type(), which returns an
178 integer type given a size and a signed-ness.
180 ** New gdb.TargetConnection object type that represents a connection
181 (as displayed by the 'info connections' command). A sub-class,
182 gdb.RemoteTargetConnection, is used to represent 'remote' and
183 'extended-remote' connections.
185 ** The gdb.Inferior type now has a 'connection' property which is an
186 instance of gdb.TargetConnection, the connection used by this
187 inferior. This can be None if the inferior has no connection.
189 ** New 'gdb.events.connection_removed' event registry, which emits a
190 'gdb.ConnectionEvent' when a connection is removed from GDB.
191 This event has a 'connection' property, a gdb.TargetConnection
192 object for the connection being removed.
194 ** New gdb.connections() function that returns a list of all
195 currently active connections.
197 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
198 is equivalent to the existing 'maint packet' CLI command; it
199 allows a user specified packet to be sent to the remote target.
201 ** New function gdb.host_charset(), returns a string, which is the
202 name of the current host charset.
204 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
207 ** New gdb.with_parameter(NAME, VALUE). This returns a context
208 manager that temporarily sets the gdb parameter NAME to VALUE,
209 then resets it when the context is exited.
211 ** The gdb.Value.format_string method now takes a 'styling'
212 argument, which is a boolean. When true, the returned string can
213 include escape sequences to apply styling. The styling will only
214 be present if styling is otherwise turned on in GDB (see 'help
215 set styling'). When false, which is the default if the argument
216 is not given, then no styling is applied to the returned string.
218 ** New read-only attribute gdb.InferiorThread.details, which is
219 either a string, containing additional, target specific thread
220 state information, or None, if there is no such additional
223 * New features in the GDB remote stub, GDBserver
225 ** GDBserver is now supported on OpenRISC GNU/Linux.
227 * New native configurations
229 GNU/Linux/OpenRISC or1k*-*-linux*
231 *** Changes in GDB 11
233 * The 'set disassembler-options' command now supports specifying options
236 * GDB now supports general memory tagging functionality if the underlying
237 architecture supports the proper primitives and hooks. Currently this is
238 enabled only for AArch64 MTE.
242 - Additional information when the inferior crashes with a SIGSEGV caused by
243 a memory tag violation.
245 - A new modifier 'm' for the "x" command, which displays allocation tags for a
246 particular memory range.
248 - Display of memory tag mismatches by "print", for addresses and
249 pointers, if memory tagging is supported by the architecture.
251 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
256 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
258 The MI -break-insert and -dprintf-insert commands now support a
259 new "--qualified" option that makes GDB interpret a specified
260 function name as a complete fully-qualified name. This is the
261 equivalent of the CLI's "break -qualified" and "dprintf
264 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
266 The MI -break-insert and -dprintf-insert commands now support a
267 '--force-condition' flag to forcibly define a condition even when
268 the condition is invalid at all locations of the breakpoint. This
269 is equivalent to the '-force-condition' flag of the CLI's "break"
272 ** '-break-condition --force'
274 The MI -break-condition command now supports a '--force' flag to
275 forcibly define a condition even when the condition is invalid at
276 all locations of the selected breakpoint. This is equivalent to
277 the '-force' flag of the CLI's "cond" command.
279 ** '-file-list-exec-source-files [--group-by-objfile]
280 [--basename | --dirname]
283 The existing -file-list-exec-source-files command now takes an
284 optional REGEXP which is used to filter the source files that are
285 included in the results.
287 By default REGEXP is matched against the full filename of the
288 source file. When one of --basename or --dirname is given then
289 REGEXP is only matched against the specified part of the full
292 When the optional --group-by-objfile flag is used the output
293 format is changed, the results are now a list of object files
294 (executable and libraries) with the source files that are
295 associated with each object file.
297 The results from -file-list-exec-source-files now include a
298 'debug-fully-read' field which takes the value 'true' or 'false'.
299 A 'true' value indicates the source file is from a compilation
300 unit that has had its debug information fully read in by GDB, a
301 value of 'false' indicates GDB has only performed a partial scan
302 of the debug information so far.
304 * GDB now supports core file debugging for x86_64 Cygwin programs.
306 * GDB will now look for the .gdbinit file in a config directory before
307 looking for ~/.gdbinit. The file is searched for in the following
308 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
309 $HOME/.gdbinit. On Apple hosts the search order is instead:
310 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
312 * GDB now supports fixed point types which are described in DWARF
313 as base types with a fixed-point encoding. Additionally, support
314 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
317 For Ada, this allows support for fixed point types without requiring
318 the use of the GNAT encoding (based on information added to the type's
319 name following a GNAT-specific format).
321 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
322 or ~/.gdbearlyinit if these files are present. These files are
323 processed earlier than any of the other initialization files and
324 can affect parts of GDB's startup that previously had already been
325 completed before the initialization files were read, for example
326 styling of the initial GDB greeting.
328 * GDB now has two new options "--early-init-command" and
329 "--early-init-eval-command" with corresponding short options "-eix"
330 and "-eiex" that allow options (that would normally appear in a
331 gdbearlyinit file) to be passed on the command line.
333 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
334 now understood by GDB, and can be used to describe the vector
335 registers of a target. The precise requirements of this register
336 feature are documented in the GDB manual.
338 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
339 supported by GDB and describes a new VPR register from the ARM MVE
340 (Helium) extension. See the GDB manual for more information.
344 ** TUI windows now support mouse actions. The mouse wheel scrolls
345 the appropriate window.
347 ** Key combinations that do not have a specific action on the
348 focused window are passed to GDB. For example, you now can use
349 Ctrl-Left/Ctrl-Right to move between words in the command window
350 regardless of which window is in focus. Previously you would
351 need to focus on the command window for such key combinations to
357 show debug event-loop
358 Control the display of debug output about GDB's event loop.
360 set print memory-tag-violations
361 show print memory-tag-violations
362 Control whether to display additional information about memory tag violations
363 when printing pointers and addresses. Architecture support for memory
364 tagging is required for this option to have an effect.
366 maintenance flush symbol-cache
367 maintenance flush register-cache
368 These new commands are equivalent to the already existing commands
369 'maintenance flush-symbol-cache' and 'flushregs' respectively.
371 maintenance flush dcache
372 A new command to flush the dcache.
374 maintenance info target-sections
375 Print GDB's internal target sections table.
378 Print the JIT code objects in the inferior known to GDB.
380 memory-tag show-logical-tag POINTER
381 Print the logical tag for POINTER.
382 memory-tag with-logical-tag POINTER TAG
383 Print POINTER with logical tag TAG.
384 memory-tag show-allocation-tag ADDRESS
385 Print the allocation tag for ADDRESS.
386 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
387 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
388 memory-tag check POINTER
389 Validate that POINTER's logical tag matches the allocation tag.
391 set startup-quietly on|off
393 When 'on', this causes GDB to act as if "-silent" were passed on the
394 command line. This command needs to be added to an early
395 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
398 set print type hex on|off
400 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
401 and offsets of struct members. When 'off', decimal notation is used.
403 set python ignore-environment on|off
404 show python ignore-environment
405 When 'on', this causes GDB's builtin Python to ignore any
406 environment variables that would otherwise affect how Python
407 behaves. This command needs to be added to an early initialization
408 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
410 set python dont-write-bytecode auto|on|off
411 show python dont-write-bytecode
412 When 'on', this causes GDB's builtin Python to not write any
413 byte-code (.pyc files) to disk. This command needs to be added to
414 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
415 order to affect GDB. When 'off' byte-code will always be written.
416 When set to 'auto' (the default) Python will check the
417 PYTHONDONTWRITEBYTECODE environment variable.
421 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
422 [-force-condition] [if CONDITION]
423 This command would previously refuse setting a breakpoint if the
424 CONDITION expression is invalid at a location. It now accepts and
425 defines the breakpoint if there is at least one location at which
426 the CONDITION is valid. The locations for which the CONDITION is
427 invalid, are automatically disabled. If CONDITION is invalid at all
428 of the locations, setting the breakpoint is still rejected. However,
429 the '-force-condition' flag can be used in this case for forcing GDB to
430 define the breakpoint, making all the current locations automatically
431 disabled. This may be useful if the user knows the condition will
432 become meaningful at a future location, e.g. due to a shared library
435 condition [-force] N COND
436 The behavior of this command is changed the same way for the 'break'
437 command as explained above. The '-force' flag can be used to force
438 GDB into defining the condition even when COND is invalid for all the
439 current locations of breakpoint N.
442 maintenance flush-symbol-cache
443 These commands are deprecated in favor of the new commands
444 'maintenance flush register-cache' and 'maintenance flush
445 symbol-cache' respectively.
447 set style version foreground COLOR
448 set style version background COLOR
449 set style version intensity VALUE
450 Control the styling of GDB's version number text.
453 When the ID parameter is omitted, then this command prints information
454 about the current inferior. When the ID parameter is present, the
455 behavior of the command is unchanged and have the inferior ID become
456 the current inferior.
458 maintenance info sections
459 The ALLOBJ keyword has been replaced with an -all-objects command
460 line flag. It is now possible to filter which sections are printed
461 even when -all-objects is passed.
463 ptype[/FLAGS] TYPE | EXPRESSION
464 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
465 notation is used when printing sizes and offsets of struct members.
466 When '/d' is set, decimal notation is used when printing sizes and
467 offsets of struct members. Default behavior is given by 'show print
471 The info sources command output has been restructured. The results
472 are now based around a list of objfiles (executable and libraries),
473 and for each objfile the source files that are part of that objfile
476 * Removed targets and native configurations
478 ARM Symbian arm*-*-symbianelf*
483 Request the remote to send allocation tags for a particular memory range.
485 Request the remote to store the specified allocation tags to the requested
490 ** Improved support for rvalue reference values:
491 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
492 value-referenced-value procedure now handles rvalue reference
495 ** New procedures for obtaining value variants:
496 value-reference-value, value-rvalue-reference-value and
499 ** Temporary breakpoints can now be created with make-breakpoint and
500 tested for using breakpoint-temporary?.
504 ** Inferior objects now contain a read-only 'connection_num' attribute that
505 gives the connection number as seen in 'info connections' and
508 ** New method gdb.Frame.level() which returns the stack level of the
511 ** New method gdb.PendingFrame.level() which returns the stack level
514 ** When hitting a catchpoint, the Python API will now emit a
515 gdb.BreakpointEvent rather than a gdb.StopEvent. The
516 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
518 ** Python TUI windows can now receive mouse click events. If the
519 Window object implements the click method, it is called for each
520 mouse click event in this window.
522 *** Changes in GDB 10
524 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
525 and "org.gnu.gdb.arc.aux". The old names are still supported but
526 must be considered obsolete. They will be deprecated after some
529 * Help and apropos commands will now show the documentation of a
530 command only once, even if that command has one or more aliases.
531 These commands now show the command name, then all of its aliases,
532 and finally the description of the command.
534 * 'help aliases' now shows only the user defined aliases. GDB predefined
535 aliases are shown together with their aliased command.
537 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
538 debugging information as well as source code.
540 When built with debuginfod, GDB can automatically query debuginfod
541 servers for the separate debug files and source code of the executable
544 To build GDB with debuginfod, pass --with-debuginfod to configure (this
545 requires libdebuginfod, the debuginfod client library).
547 debuginfod is distributed with elfutils, starting with version 0.178.
549 You can get the latest version from https://sourceware.org/elfutils.
551 * Multi-target debugging support
553 GDB now supports debugging multiple target connections
554 simultaneously. For example, you can now have each inferior
555 connected to different remote servers running in different machines,
556 or have one inferior debugging a local native process, an inferior
557 debugging a core dump, etc.
559 This support is experimental and comes with some limitations -- you
560 can only resume multiple targets simultaneously if all targets
561 support non-stop mode, and all remote stubs or servers must support
562 the same set of remote protocol features exactly. See also "info
563 connections" and "add-inferior -no-connection" below, and "maint set
564 target-non-stop" in the user manual.
566 * New features in the GDB remote stub, GDBserver
568 ** GDBserver is now supported on ARC GNU/Linux.
570 ** GDBserver is now supported on RISC-V GNU/Linux.
572 ** GDBserver no longer supports these host triplets:
583 i[34567]86-*-mingw32ce*
585 * Debugging MS-Windows processes now sets $_exitsignal when the
586 inferior is terminated by a signal, instead of setting $_exitcode.
588 * Multithreaded symbol loading has now been enabled by default on systems
589 that support it (see entry for GDB 9, below), providing faster
590 performance for programs with many symbols.
592 * The $_siginfo convenience variable now also works on Windows targets,
593 and will display the EXCEPTION_RECORD of the last handled exception.
595 * TUI windows can now be arranged horizontally.
597 * The command history filename can now be set to the empty string
598 either using 'set history filename' or by setting 'GDBHISTFILE=' in
599 the environment. The effect of setting this filename to the empty
600 string is that GDB will not try to load any previous command
603 * On Windows targets, it is now possible to debug 32-bit programs with a
608 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
609 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
610 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
611 running process, this new option indicates whether to detect
612 a mismatch between the current executable file loaded by GDB and the
613 executable file used to start the process. If 'ask', the default,
614 display a warning and ask the user whether to load the process
615 executable file; if 'warn', just display a warning; if 'off', don't
616 attempt to detect a mismatch.
618 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
619 Define a new TUI layout, specifying its name and the windows that
622 maintenance print xml-tdesc [FILE]
623 Prints the current target description as an XML document. If the
624 optional FILE is provided (which is an XML target description) then
625 the target description is read from FILE into GDB, and then
628 maintenance print core-file-backed-mappings
629 Prints file-backed mappings loaded from a core file's note section.
630 Output is expected to be similar to that of "info proc mappings".
632 set debug fortran-array-slicing on|off
633 show debug fortran-array-slicing
634 Print debugging when taking slices of Fortran arrays.
636 set fortran repack-array-slices on|off
637 show fortran repack-array-slices
638 When taking slices from Fortran arrays and strings, if the slice is
639 non-contiguous within the original value then, when this option is
640 on, the new value will be repacked into a single contiguous value.
641 When this option is off, then the value returned will consist of a
642 descriptor that describes the slice within the memory of the
643 original parent value.
647 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
648 The alias command can now specify default args for an alias.
649 GDB automatically prepends the alias default args to the argument list
650 provided explicitly by the user.
651 For example, to have a backtrace with full details, you can define
653 'alias bt_ALL = backtrace -entry-values both -frame-arg all
654 -past-main -past-entry -full'.
655 Alias default arguments can also use a set of nested 'with' commands,
656 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
657 defines the alias pp10 that will pretty print a maximum of 10 elements
658 of the given expression (if the expression is an array).
662 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
668 ** gdb.register_window_type can be used to implement new TUI windows
671 ** Dynamic types can now be queried. gdb.Type has a new attribute,
672 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
673 field of a dynamic type may have None for its "bitpos" attribute
676 ** Commands written in Python can be in the "TUI" help class by
677 registering with the new constant gdb.COMMAND_TUI.
679 ** New method gdb.PendingFrame.architecture () to retrieve the
680 architecture of the pending frame.
682 ** New gdb.Architecture.registers method that returns a
683 gdb.RegisterDescriptorIterator object, an iterator that returns
684 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
685 way to query the registers available for an architecture.
687 ** New gdb.Architecture.register_groups method that returns a
688 gdb.RegisterGroupIterator object, an iterator that returns
689 gdb.RegisterGroup objects. The new RegisterGroup is a way to
690 discover the available register groups.
694 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
696 ** Procedures 'memory-port-read-buffer-size',
697 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
698 and 'set-memory-port-write-buffer-size!' are deprecated. When
699 using Guile 2.2 and later, users who need to control the size of
700 a memory port's internal buffer can use the 'setvbuf' procedure.
704 * 'thread-exited' event is now available in the annotations interface.
706 * New built-in convenience variables $_gdb_major and $_gdb_minor
707 provide the GDB version. They are handy for conditionally using
708 features available only in or since specific GDB versions, in
709 scripts that should work error-free with many different versions,
710 such as in system-wide init files.
712 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
713 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
714 of the GDB settings and the GDB maintenance settings. They are handy
715 for changing the logic of user defined commands depending on the
716 current GDB settings.
718 * GDB now supports Thread Local Storage (TLS) variables on several
719 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
720 architectures require kernel changes. TLS is not yet supported for
721 amd64 and i386 process core dumps.
723 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
724 addresses that required unmasking are shown in the backtrace with the
727 * Two new convenience functions $_cimag and $_creal that extract the
728 imaginary and real parts respectively from complex numbers.
730 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
731 provide the exitcode or exit status of the shell commands launched by
732 GDB commands such as "shell", "pipe" and "make".
734 * The command define-prefix can now define user defined prefix commands.
735 User defined commands can now be defined using these user defined prefix
738 * Command names can now use the . character.
740 * The RX port now supports XML target descriptions.
742 * GDB now shows the Ada task names at more places, e.g. in task switching
745 * GDB can now be compiled with Python 3 on Windows.
747 * New convenience variable $_ada_exception holds the address of the
748 Ada exception being thrown. This is set by Ada-related catchpoints.
750 * GDB can now place breakpoints on nested functions and subroutines in
751 Fortran code. The '::' operator can be used between parent and
752 child scopes when placing breakpoints, for example:
754 (gdb) break outer_function::inner_function
756 The 'outer_function::' prefix is only needed if 'inner_function' is
757 not visible in the current scope.
759 * In addition to the system-wide gdbinit file, if configured with
760 --with-system-gdbinit-dir, GDB will now also load files in that directory
761 as system gdbinit files, unless the -nx or -n flag is provided. Files
762 with extensions .gdb, .py and .scm are supported as long as GDB was
763 compiled with support for that language.
765 * GDB now supports multithreaded symbol loading for higher performance.
766 This feature is still in testing, so it is disabled by default. You
767 can turn it on using 'maint set worker-threads unlimited'.
771 ** The gdb.Value type has a new method 'format_string' which returns a
772 string representing the value. The formatting is controlled by the
773 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
774 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
775 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
777 ** gdb.Type has a new property 'objfile' which returns the objfile the
780 ** The frame information printed by the python frame filtering code
781 is now consistent with what the 'backtrace' command prints when
782 there are no filters, or when the 'backtrace' '-no-filters' option
785 ** The new function gdb.lookup_static_symbol can be used to look up
786 symbols with static linkage.
788 ** The new function gdb.lookup_static_symbols can be used to look up
789 all static symbols with static linkage.
791 ** gdb.Objfile has new methods 'lookup_global_symbol' and
792 'lookup_static_symbol' to lookup a symbol from this objfile only.
794 ** gdb.Block now supports the dictionary syntax for accessing symbols in
795 this block (e.g. block['local_variable']).
799 | [COMMAND] | SHELL_COMMAND
800 | -d DELIM COMMAND DELIM SHELL_COMMAND
801 pipe [COMMAND] | SHELL_COMMAND
802 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
803 Executes COMMAND and sends its output to SHELL_COMMAND.
804 With no COMMAND, repeat the last executed command
805 and send its output to SHELL_COMMAND.
807 define-prefix COMMAND
808 Define or mark a command as a user-defined prefix command.
810 with SETTING [VALUE] [-- COMMAND]
811 w SETTING [VALUE] [-- COMMAND]
812 Temporarily set SETTING, run COMMAND, and restore SETTING.
813 Usage: with SETTING -- COMMAND
814 With no COMMAND, repeats the last executed command.
815 SETTING is any GDB setting you can change with the "set"
816 subcommands. For example, 'with language c -- print someobj'
817 temporarily switches to the C language in order to print someobj.
818 Settings can be combined: 'w lang c -- w print elements unlimited --
819 usercmd' switches to the C language and runs usercmd with no limit
820 of array elements to print.
822 maint with SETTING [VALUE] [-- COMMAND]
823 Like "with", but works with "maintenance set" settings.
825 set may-call-functions [on|off]
826 show may-call-functions
827 This controls whether GDB will attempt to call functions in
828 the program, such as with expressions in the print command. It
829 defaults to on. Calling functions in the program being debugged
830 can have undesired side effects. It is now possible to forbid
831 such function calls. If function calls are forbidden, GDB will throw
832 an error when a command (such as print expression) calls a function
835 set print finish [on|off]
837 This controls whether the `finish' command will display the value
838 that is returned by the current function. When `off', the value is
839 still entered into the value history, but it is not printed. The
844 Allows deeply nested structures to be simplified when printing by
845 replacing deeply nested parts (beyond the max-depth) with ellipses.
846 The default max-depth is 20, but this can be set to unlimited to get
847 the old behavior back.
849 set print raw-values [on|off]
850 show print raw-values
851 By default, GDB applies the enabled pretty printers when printing a
852 value. This allows to ignore the enabled pretty printers for a series
853 of commands. The default is 'off'.
855 set logging debugredirect [on|off]
856 By default, GDB debug output will go to both the terminal and the logfile.
857 Set if you want debug output to go only to the log file.
859 set style title foreground COLOR
860 set style title background COLOR
861 set style title intensity VALUE
862 Control the styling of titles.
864 set style highlight foreground COLOR
865 set style highlight background COLOR
866 set style highlight intensity VALUE
867 Control the styling of highlightings.
869 maint set worker-threads
870 maint show worker-threads
871 Control the number of worker threads that can be used by GDB. The
872 default is 0. "unlimited" lets GDB choose a number that is
873 reasonable. Currently worker threads are only used when demangling
874 the names of linker symbols.
876 set style tui-border foreground COLOR
877 set style tui-border background COLOR
878 Control the styling of TUI borders.
880 set style tui-active-border foreground COLOR
881 set style tui-active-border background COLOR
882 Control the styling of the active TUI border.
884 maint set test-settings KIND
885 maint show test-settings KIND
886 A set of commands used by the testsuite for exercising the settings
889 maint set tui-resize-message [on|off]
890 maint show tui-resize-message
891 Control whether GDB prints a message each time the terminal is
892 resized when in TUI mode. This is primarily useful for testing the
895 set print frame-info [short-location|location|location-and-address
896 |source-and-location|source-line|auto]
897 show print frame-info
898 This controls what frame information is printed by the commands printing
899 a frame. This setting will e.g. influence the behaviour of 'backtrace',
900 'frame', 'stepi'. The python frame filtering also respect this setting.
901 The 'backtrace' '-frame-info' option can override this global setting.
903 set tui compact-source
904 show tui compact-source
906 Enable the "compact" display mode for the TUI source window. The
907 compact display uses only as much space as is needed for the line
908 numbers in the current file, and only a single space to separate the
909 line numbers from the source.
911 info modules [-q] [REGEXP]
912 Return a list of Fortran modules matching REGEXP, or all modules if
915 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
916 Return a list of functions within all modules, grouped by module.
917 The list of functions can be restricted with the optional regular
918 expressions. MODULE_REGEXP matches against the module name,
919 TYPE_REGEXP matches against the function type signature, and REGEXP
920 matches against the function name.
922 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
923 Return a list of variables within all modules, grouped by module.
924 The list of variables can be restricted with the optional regular
925 expressions. MODULE_REGEXP matches against the module name,
926 TYPE_REGEXP matches against the variable type, and REGEXP matches
927 against the variable name.
929 set debug remote-packet-max-chars
930 show debug remote-packet-max-chars
931 Controls the number of characters to output in a remote packet when using
933 The default is 512 bytes.
936 Lists the target connections currently in use.
941 The "help" command uses the title style to enhance the
942 readibility of its output by styling the classes and
946 Similarly to "help", the "apropos" command also uses the
947 title style for the command names. "apropos" accepts now
948 a flag "-v" (verbose) to show the full documentation
949 of matching commands and to use the highlight style to mark
950 the documentation parts matching REGEXP.
954 The GDB printf and eval commands can now print C-style and Ada-style
955 string convenience variables without calling functions in the program.
956 This allows to do formatted printing of strings without having
957 a running inferior, or when debugging a core dump.
959 info sources [-dirname | -basename] [--] [REGEXP]
960 This command has now optional arguments to only print the files
961 whose names match REGEXP. The arguments -dirname and -basename
962 allow to restrict matching respectively to the dirname and basename
966 The "show style" and its subcommands are now styling
967 a style name in their output using its own style, to help
968 the user visualize the different styles.
970 set print frame-arguments
971 The new value 'presence' indicates to only indicate the presence of
972 arguments using ..., instead of printing argument names and values.
974 set print raw-frame-arguments
975 show print raw-frame-arguments
977 These commands replace the similarly-named "set/show print raw
978 frame-arguments" commands (now with a dash instead of a space). The
979 old commands are now deprecated and may be removed in a future
982 add-inferior [-no-connection]
983 The add-inferior command now supports a "-no-connection" flag that
984 makes the new inferior start with no target connection associated.
985 By default, the new inferior inherits the target connection of the
986 current inferior. See also "info connections".
989 This command's output now includes a new "Connection" column
990 indicating which target connection an inferior is bound to. See
991 "info connections" above.
993 maint test-options require-delimiter
994 maint test-options unknown-is-error
995 maint test-options unknown-is-operand
996 maint show test-options-completion-result
997 Commands used by the testsuite to validate the command options
1000 focus, winheight, +, -, >, <
1001 These commands are now case-sensitive.
1003 * New command options, command completion
1005 GDB now has a standard infrastructure to support dash-style command
1006 options ('-OPT'). One benefit is that commands that use it can
1007 easily support completion of command line arguments. Try "CMD
1008 -[TAB]" or "help CMD" to find options supported by a command. Over
1009 time, we intend to migrate most commands to this infrastructure. A
1010 number of commands got support for new command options in this
1013 ** The "print" and "compile print" commands now support a number of
1014 options that allow overriding relevant global print settings as
1015 set by "set print" subcommands:
1019 -array-indexes [on|off]
1020 -elements NUMBER|unlimited
1024 -raw-values [on|off]
1025 -repeats NUMBER|unlimited
1026 -static-members [on|off]
1031 Note that because the "print"/"compile print" commands accept
1032 arbitrary expressions which may look like options (including
1033 abbreviations), if you specify any command option, then you must
1034 use a double dash ("--") to mark the end of argument processing.
1036 ** The "backtrace" command now supports a number of options that
1037 allow overriding relevant global print settings as set by "set
1038 backtrace" and "set print" subcommands:
1040 -entry-values no|only|preferred|if-needed|both|compact|default
1041 -frame-arguments all|scalars|none
1042 -raw-frame-arguments [on|off]
1043 -frame-info auto|source-line|location|source-and-location
1044 |location-and-address|short-location
1046 -past-entry [on|off]
1048 In addition, the full/no-filters/hide qualifiers are now also
1049 exposed as command options too:
1055 ** The "frame apply", "tfaas" and "faas" commands similarly now
1056 support the following options:
1059 -past-entry [on|off]
1061 ** The new "info sources" options -dirname and -basename options
1062 are using the standard '-OPT' infrastructure.
1064 All options above can also be abbreviated. The argument of boolean
1065 (on/off) options can be 0/1 too, and also the argument is assumed
1066 "on" if omitted. This allows writing compact command invocations,
1069 (gdb) p -ra -p -o 0 -- *myptr
1071 The above is equivalent to:
1073 (gdb) print -raw-values -pretty -object off -- *myptr
1075 ** The "info types" command now supports the '-q' flag to disable
1076 printing of some header information in a similar fashion to "info
1077 variables" and "info functions".
1079 ** The "info variables", "info functions", and "whereis" commands
1080 now take a '-n' flag that excludes non-debug symbols (symbols
1081 from the symbol table, not from the debug info such as DWARF)
1084 * Completion improvements
1086 ** GDB can now complete the options of the "thread apply all" and
1087 "taas" commands, and their "-ascending" option can now be
1090 ** GDB can now complete the options of the "info threads", "info
1091 functions", "info variables", "info locals", and "info args"
1094 ** GDB can now complete the options of the "compile file" and
1095 "compile code" commands. The "compile file" command now
1096 completes on filenames.
1098 ** GDB can now complete the backtrace command's
1099 "full/no-filters/hide" qualifiers.
1101 * In settings, you can now abbreviate "unlimited".
1103 E.g., "set print elements u" is now equivalent to "set print
1104 elements unlimited".
1109 This lists all the possible completions for the rest of the line, if it
1110 were to be given as a command itself. This is intended for use by MI
1111 frontends in cases when separate CLI and MI channels cannot be used.
1113 -catch-throw, -catch-rethrow, and -catch-catch
1114 These can be used to catch C++ exceptions in a similar fashion to
1115 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1117 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1118 These commands are the MI equivalent of the CLI commands 'info
1119 functions', 'info types', and 'info variables' respectively.
1121 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1124 -symbol-info-module-functions and -symbol-info-module-variables.
1125 These commands are the MI equivalent of the CLI commands 'info
1126 module functions' and 'info module variables'.
1130 ** The default version of the MI interpreter is now 3 (-i=mi3).
1132 ** The output of information about multi-location breakpoints (which is
1133 syntactically incorrect in MI 2) has changed in MI 3. This affects
1134 the following commands and events:
1138 - =breakpoint-created
1139 - =breakpoint-modified
1141 The -fix-multi-location-breakpoint-output command can be used to enable
1142 this behavior with previous MI versions.
1144 ** Backtraces and frames include a new optional field addr_flags which is
1145 given after the addr field. On AArch64 this contains PAC if the address
1146 has been masked in the frame. On all other targets the field is not
1151 The testsuite now creates the files gdb.cmd (containing the arguments
1152 used to launch GDB) and gdb.in (containing all the commands sent to
1153 GDB) in the output directory for each test script. Multiple invocations
1154 are appended with .1, .2, .3 etc.
1156 * Building GDB and GDBserver now requires GNU make >= 3.82.
1158 Using another implementation of the make program or an earlier version of
1159 GNU make to build GDB or GDBserver is not supported.
1161 * Building GDB now requires GNU readline >= 7.0.
1163 GDB now bundles GNU readline 8.0, but if you choose to use
1164 --with-system-readline, only readline >= 7.0 can be used.
1166 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1167 from .inputrc to bind keys in this keymap. This feature is only
1168 available when gdb is built against GNU readline 8.0 or later.
1170 * Removed targets and native configurations
1172 GDB no longer supports debugging the Cell Broadband Engine. This includes
1173 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1174 of Cell/B.E. applications that use both the PPU and SPU architectures.
1180 * Removed targets and native configurations
1182 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1183 sparc*-*-solaris2.10
1185 *** Changes in GDB 8.3
1187 * GDB and GDBserver now support access to additional registers on
1188 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1191 * GDB now has experimental support for the compilation and injection of
1192 C++ source code into the inferior. This beta release does not include
1193 support for several language features, such as templates, constructors,
1196 This feature requires GCC 7.1 or higher built with libcp1.so
1199 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1200 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1201 'ADDRESS:PORT' method.
1203 * DWARF index cache: GDB can now automatically save indices of DWARF
1204 symbols on disk to speed up further loading of the same binaries.
1206 * Ada task switching is now supported on aarch64-elf targets when
1207 debugging a program using the Ravenscar Profile. For more information,
1208 see the "Tasking Support when using the Ravenscar Profile" section
1209 in the GDB user manual.
1211 * GDB in batch mode now exits with status 1 if the last command to be
1214 * The RISC-V target now supports target descriptions.
1216 * System call catchpoints now support system call aliases on FreeBSD.
1217 When the ABI of a system call changes in FreeBSD, this is
1218 implemented by leaving a compatibility system call using the old ABI
1219 at the existing number and allocating a new system call number for
1220 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1221 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1222 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1223 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1224 so that a system call catchpoint for the 'kevent' system call will
1225 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1226 binaries. This ensures that 'kevent' system calls are caught for
1227 binaries using either the old or new ABIs.
1229 * Terminal styling is now available for the CLI and the TUI. GNU
1230 Source Highlight can additionally be used to provide styling of
1231 source code snippets. See the "set style" commands, below, for more
1234 * Removed support for old demangling styles arm, edg, gnu, hp and
1239 set debug compile-cplus-types
1240 show debug compile-cplus-types
1241 Control the display of debug output about type conversion in the
1242 C++ compile feature. Commands have no effect while compiling
1243 for other languages.
1247 Control whether debug output about files/functions skipping is
1250 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1251 Apply a command to some frames.
1252 FLAG arguments allow to control what output to produce and how to handle
1253 errors raised when applying COMMAND to a frame.
1256 Apply a command to all threads (ignoring errors and empty output).
1257 Shortcut for 'thread apply all -s COMMAND'.
1260 Apply a command to all frames (ignoring errors and empty output).
1261 Shortcut for 'frame apply all -s COMMAND'.
1264 Apply a command to all frames of all threads (ignoring errors and empty
1266 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1268 maint set dwarf unwinders (on|off)
1269 maint show dwarf unwinders
1270 Control whether DWARF unwinders can be used.
1273 Display a list of open files for a process.
1277 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1278 These commands all now take a frame specification which
1279 is either a frame level, or one of the keywords 'level', 'address',
1280 'function', or 'view' followed by a parameter. Selecting a frame by
1281 address, or viewing a frame outside the current backtrace now
1282 requires the use of a keyword. Selecting a frame by level is
1283 unchanged. The MI comment "-stack-select-frame" is unchanged.
1285 target remote FILENAME
1286 target extended-remote FILENAME
1287 If FILENAME is a Unix domain socket, GDB will attempt to connect
1288 to this socket instead of opening FILENAME as a character device.
1290 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1291 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1292 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1293 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1294 These commands can now print only the searched entities
1295 matching the provided regexp(s), giving a condition
1296 on the entity names or entity types. The flag -q disables
1297 printing headers or informations messages.
1303 These commands now determine the syntax for the shown entities
1304 according to the language chosen by `set language'. In particular,
1305 `set language auto' means to automatically choose the language of
1308 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1309 The 'thread apply' command accepts new FLAG arguments.
1310 FLAG arguments allow to control what output to produce and how to handle
1311 errors raised when applying COMMAND to a thread.
1313 set tui tab-width NCHARS
1314 show tui tab-width NCHARS
1315 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1317 set style enabled [on|off]
1319 Enable or disable terminal styling. Styling is enabled by default
1320 on most hosts, but disabled by default when in batch mode.
1322 set style sources [on|off]
1324 Enable or disable source code styling. Source code styling is
1325 enabled by default, but only takes effect if styling in general is
1326 enabled, and if GDB was linked with GNU Source Highlight.
1328 set style filename foreground COLOR
1329 set style filename background COLOR
1330 set style filename intensity VALUE
1331 Control the styling of file names.
1333 set style function foreground COLOR
1334 set style function background COLOR
1335 set style function intensity VALUE
1336 Control the styling of function names.
1338 set style variable foreground COLOR
1339 set style variable background COLOR
1340 set style variable intensity VALUE
1341 Control the styling of variable names.
1343 set style address foreground COLOR
1344 set style address background COLOR
1345 set style address intensity VALUE
1346 Control the styling of addresses.
1350 ** The '-data-disassemble' MI command now accepts an '-a' option to
1351 disassemble the whole function surrounding the given program
1352 counter value or function name. Support for this feature can be
1353 verified by using the "-list-features" command, which should
1354 contain "data-disassemble-a-option".
1356 ** Command responses and notifications that include a frame now include
1357 the frame's architecture in a new "arch" attribute.
1359 * New native configurations
1361 GNU/Linux/RISC-V riscv*-*-linux*
1362 FreeBSD/riscv riscv*-*-freebsd*
1366 GNU/Linux/RISC-V riscv*-*-linux*
1367 CSKY ELF csky*-*-elf
1368 CSKY GNU/LINUX csky*-*-linux
1369 FreeBSD/riscv riscv*-*-freebsd*
1371 GNU/Linux/OpenRISC or1k*-*-linux*
1375 GDB no longer supports native debugging on versions of MS-Windows
1380 ** GDB no longer supports Python versions less than 2.6.
1382 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1383 space associated to that inferior.
1385 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1386 of objfiles associated to that program space.
1388 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1389 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1392 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1393 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1394 correct and did not work properly.
1396 ** The gdb.Value type has a new constructor, which is used to construct a
1397 gdb.Value from a Python buffer object and a gdb.Type.
1403 Enable or disable the undefined behavior sanitizer. This is
1404 disabled by default, but passing --enable-ubsan=yes or
1405 --enable-ubsan=auto to configure will enable it. Enabling this can
1406 cause a performance penalty. The undefined behavior sanitizer was
1407 first introduced in GCC 4.9.
1409 *** Changes in GDB 8.2
1411 * The 'set disassembler-options' command now supports specifying options
1412 for the MIPS target.
1414 * The 'symbol-file' command now accepts an '-o' option to add a relative
1415 offset to all sections.
1417 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1418 a relative offset to all sections, but it allows to override the load
1419 address of individual sections using '-s'.
1421 * The 'add-symbol-file' command no longer requires the second argument
1422 (address of the text section).
1424 * The endianness used with the 'set endian auto' mode in the absence of
1425 an executable selected for debugging is now the last endianness chosen
1426 either by one of the 'set endian big' and 'set endian little' commands
1427 or by inferring from the last executable used, rather than the startup
1430 * The pager now allows a "c" response, meaning to disable the pager
1431 for the rest of the current command.
1433 * The commands 'info variables/functions/types' now show the source line
1434 numbers of symbol definitions when available.
1436 * 'info proc' now works on running processes on FreeBSD systems and core
1437 files created on FreeBSD systems.
1439 * C expressions can now use _Alignof, and C++ expressions can now use
1442 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1443 the vector length while the process is running.
1449 Control display of debugging info regarding the FreeBSD native target.
1451 set|show varsize-limit
1452 This new setting allows the user to control the maximum size of Ada
1453 objects being printed when those objects have a variable type,
1454 instead of that maximum size being hardcoded to 65536 bytes.
1456 set|show record btrace cpu
1457 Controls the processor to be used for enabling errata workarounds for
1458 branch trace decode.
1460 maint check libthread-db
1461 Run integrity checks on the current inferior's thread debugging
1464 maint set check-libthread-db (on|off)
1465 maint show check-libthread-db
1466 Control whether to run integrity checks on inferior specific thread
1467 debugging libraries as they are loaded. The default is not to
1468 perform such checks.
1472 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1474 ** The commands attached to a breakpoint can be set by assigning to
1475 the breakpoint's "commands" field.
1477 ** gdb.execute can now execute multi-line gdb commands.
1479 ** The new functions gdb.convenience_variable and
1480 gdb.set_convenience_variable can be used to get and set the value
1481 of convenience variables.
1483 ** A gdb.Parameter will no longer print the "set" help text on an
1484 ordinary "set"; instead by default a "set" will be silent unless
1485 the get_set_string method returns a non-empty string.
1489 RiscV ELF riscv*-*-elf
1491 * Removed targets and native configurations
1493 m88k running OpenBSD m88*-*-openbsd*
1494 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1495 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1496 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1498 * Aarch64/Linux hardware watchpoints improvements
1500 Hardware watchpoints on unaligned addresses are now properly
1501 supported when running Linux kernel 4.10 or higher: read and access
1502 watchpoints are no longer spuriously missed, and all watchpoints
1503 lengths between 1 and 8 bytes are supported. On older kernels,
1504 watchpoints set on unaligned addresses are no longer missed, with
1505 the tradeoff that there is a possibility of false hits being
1510 --enable-codesign=CERT
1511 This can be used to invoke "codesign -s CERT" after building gdb.
1512 This option is useful on macOS, where code signing is required for
1513 gdb to work properly.
1515 --disable-gdbcli has been removed
1516 This is now silently accepted, but does nothing.
1518 *** Changes in GDB 8.1
1520 * GDB now supports dynamically creating arbitrary register groups specified
1521 in XML target descriptions. This allows for finer grain grouping of
1522 registers on systems with a large amount of registers.
1524 * The 'ptype' command now accepts a '/o' flag, which prints the
1525 offsets and sizes of fields in a struct, like the pahole(1) tool.
1527 * New "--readnever" command line option instructs GDB to not read each
1528 symbol file's symbolic debug information. This makes startup faster
1529 but at the expense of not being able to perform symbolic debugging.
1530 This option is intended for use cases where symbolic debugging will
1531 not be used, e.g., when you only need to dump the debuggee's core.
1533 * GDB now uses the GNU MPFR library, if available, to emulate target
1534 floating-point arithmetic during expression evaluation when the target
1535 uses different floating-point formats than the host. At least version
1536 3.1 of GNU MPFR is required.
1538 * GDB now supports access to the guarded-storage-control registers and the
1539 software-based guarded-storage broadcast control registers on IBM z14.
1541 * On Unix systems, GDB now supports transmitting environment variables
1542 that are to be set or unset to GDBserver. These variables will
1543 affect the environment to be passed to the remote inferior.
1545 To inform GDB of environment variables that are to be transmitted to
1546 GDBserver, use the "set environment" command. Only user set
1547 environment variables are sent to GDBserver.
1549 To inform GDB of environment variables that are to be unset before
1550 the remote inferior is started by the GDBserver, use the "unset
1551 environment" command.
1553 * Completion improvements
1555 ** GDB can now complete function parameters in linespecs and
1556 explicit locations without quoting. When setting breakpoints,
1557 quoting around functions names to help with TAB-completion is
1558 generally no longer necessary. For example, this now completes
1561 (gdb) b function(in[TAB]
1562 (gdb) b function(int)
1564 Related, GDB is no longer confused with completing functions in
1565 C++ anonymous namespaces:
1568 (gdb) b (anonymous namespace)::[TAB][TAB]
1569 (anonymous namespace)::a_function()
1570 (anonymous namespace)::b_function()
1572 ** GDB now has much improved linespec and explicit locations TAB
1573 completion support, that better understands what you're
1574 completing and offers better suggestions. For example, GDB no
1575 longer offers data symbols as possible completions when you're
1576 setting a breakpoint.
1578 ** GDB now TAB-completes label symbol names.
1580 ** The "complete" command now mimics TAB completion accurately.
1582 * New command line options (gcore)
1585 Dump all memory mappings.
1587 * Breakpoints on C++ functions are now set on all scopes by default
1589 By default, breakpoints on functions/methods are now interpreted as
1590 specifying all functions with the given name ignoring missing
1591 leading scopes (namespaces and classes).
1593 For example, assuming a C++ program with symbols named:
1598 both commands "break func()" and "break B::func()" set a breakpoint
1601 You can use the new flag "-qualified" to override this. This makes
1602 GDB interpret the specified function name as a complete
1603 fully-qualified name instead. For example, using the same C++
1604 program, the "break -q B::func" command sets a breakpoint on
1605 "B::func", only. A parameter has been added to the Python
1606 gdb.Breakpoint constructor to achieve the same result when creating
1607 a breakpoint from Python.
1609 * Breakpoints on functions marked with C++ ABI tags
1611 GDB can now set breakpoints on functions marked with C++ ABI tags
1612 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1613 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1615 Functions with a C++11 abi tag are demangled/displayed like this:
1617 function[abi:cxx11](int)
1620 You can now set a breakpoint on such functions simply as if they had
1623 (gdb) b function(int)
1625 Or if you need to disambiguate between tags, like:
1627 (gdb) b function[abi:other_tag](int)
1629 Tab completion was adjusted accordingly as well.
1633 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1634 gdb.new_thread are emitted. See the manual for further
1635 description of these.
1637 ** A new function, "gdb.rbreak" has been added to the Python API.
1638 This function allows the setting of a large number of breakpoints
1639 via a regex pattern in Python. See the manual for further details.
1641 ** Python breakpoints can now accept explicit locations. See the
1642 manual for a further description of this feature.
1645 * New features in the GDB remote stub, GDBserver
1647 ** GDBserver is now able to start inferior processes with a
1648 specified initial working directory.
1650 The user can set the desired working directory to be used from
1651 GDB using the new "set cwd" command.
1653 ** New "--selftest" command line option runs some GDBserver self
1654 tests. These self tests are disabled in releases.
1656 ** On Unix systems, GDBserver now does globbing expansion and variable
1657 substitution in inferior command line arguments.
1659 This is done by starting inferiors using a shell, like GDB does.
1660 See "set startup-with-shell" in the user manual for how to disable
1661 this from GDB when using "target extended-remote". When using
1662 "target remote", you can disable the startup with shell by using the
1663 new "--no-startup-with-shell" GDBserver command line option.
1665 ** On Unix systems, GDBserver now supports receiving environment
1666 variables that are to be set or unset from GDB. These variables
1667 will affect the environment to be passed to the inferior.
1669 * When catching an Ada exception raised with a message, GDB now prints
1670 the message in the catchpoint hit notification. In GDB/MI mode, that
1671 information is provided as an extra field named "exception-message"
1672 in the *stopped notification.
1674 * Trait objects can now be inspected When debugging Rust code. This
1675 requires compiler support which will appear in Rust 1.24.
1677 * New remote packets
1679 QEnvironmentHexEncoded
1680 Inform GDBserver of an environment variable that is to be passed to
1681 the inferior when starting it.
1684 Inform GDBserver of an environment variable that is to be unset
1685 before starting the remote inferior.
1688 Inform GDBserver that the environment should be reset (i.e.,
1689 user-set environment variables should be unset).
1692 Indicates whether the inferior must be started with a shell or not.
1695 Tell GDBserver that the inferior to be started should use a specific
1698 * The "maintenance print c-tdesc" command now takes an optional
1699 argument which is the file name of XML target description.
1701 * The "maintenance selftest" command now takes an optional argument to
1702 filter the tests to be run.
1704 * The "enable", and "disable" commands now accept a range of
1705 breakpoint locations, e.g. "enable 1.3-5".
1710 Set and show the current working directory for the inferior.
1712 set|show compile-gcc
1713 Set and show compilation command used for compiling and injecting code
1714 with the 'compile' commands.
1716 set debug separate-debug-file
1717 show debug separate-debug-file
1718 Control the display of debug output about separate debug file search.
1720 set dump-excluded-mappings
1721 show dump-excluded-mappings
1722 Control whether mappings marked with the VM_DONTDUMP flag should be
1723 dumped when generating a core file.
1725 maint info selftests
1726 List the registered selftests.
1729 Start the debugged program stopping at the first instruction.
1732 Control display of debugging messages related to OpenRISC targets.
1734 set|show print type nested-type-limit
1735 Set and show the limit of nesting level for nested types that the
1736 type printer will show.
1738 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1741 * Safer/improved support for debugging with no debug info
1743 GDB no longer assumes functions with no debug information return
1746 This means that GDB now refuses to call such functions unless you
1747 tell it the function's type, by either casting the call to the
1748 declared return type, or by casting the function to a function
1749 pointer of the right type, and calling that:
1751 (gdb) p getenv ("PATH")
1752 'getenv' has unknown return type; cast the call to its declared return type
1753 (gdb) p (char *) getenv ("PATH")
1754 $1 = 0x7fffffffe "/usr/local/bin:/"...
1755 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1756 $2 = 0x7fffffffe "/usr/local/bin:/"...
1758 Similarly, GDB no longer assumes that global variables with no debug
1759 info have type 'int', and refuses to print the variable's value
1760 unless you tell it the variable's type:
1763 'var' has unknown type; cast it to its declared type
1767 * New native configurations
1769 FreeBSD/aarch64 aarch64*-*-freebsd*
1770 FreeBSD/arm arm*-*-freebsd*
1774 FreeBSD/aarch64 aarch64*-*-freebsd*
1775 FreeBSD/arm arm*-*-freebsd*
1776 OpenRISC ELF or1k*-*-elf
1778 * Removed targets and native configurations
1780 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1782 *** Changes in GDB 8.0
1784 * GDB now supports access to the PKU register on GNU/Linux. The register is
1785 added by the Memory Protection Keys for Userspace feature which will be
1786 available in future Intel CPUs.
1788 * GDB now supports C++11 rvalue references.
1792 ** New functions to start, stop and access a running btrace recording.
1793 ** Rvalue references are now supported in gdb.Type.
1795 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1798 * Building GDB and GDBserver now requires a C++11 compiler.
1800 For example, GCC 4.8 or later.
1802 It is no longer possible to build GDB or GDBserver with a C
1803 compiler. The --disable-build-with-cxx configure option has been
1806 * Building GDB and GDBserver now requires GNU make >= 3.81.
1808 It is no longer supported to build GDB or GDBserver with another
1809 implementation of the make program or an earlier version of GNU make.
1811 * Native debugging on MS-Windows supports command-line redirection
1813 Command-line arguments used for starting programs on MS-Windows can
1814 now include redirection symbols supported by native Windows shells,
1815 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1816 as "run", "start", and "set args", as well as the corresponding MI
1819 * Support for thread names on MS-Windows.
1821 GDB now catches and handles the special exception that programs
1822 running on MS-Windows use to assign names to threads in the
1825 * Support for Java programs compiled with gcj has been removed.
1827 * User commands now accept an unlimited number of arguments.
1828 Previously, only up to 10 was accepted.
1830 * The "eval" command now expands user-defined command arguments.
1832 This makes it easier to process a variable number of arguments:
1837 eval "print $arg%d", $i
1842 * Target descriptions can now describe registers for sparc32 and sparc64.
1844 * GDB now supports DWARF version 5 (debug information format).
1845 Its .debug_names index is not yet supported.
1847 * New native configurations
1849 FreeBSD/mips mips*-*-freebsd
1853 Synopsys ARC arc*-*-elf32
1854 FreeBSD/mips mips*-*-freebsd
1856 * Removed targets and native configurations
1858 Alpha running FreeBSD alpha*-*-freebsd*
1859 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1864 Erases all the flash memory regions reported by the target.
1866 maint print arc arc-instruction address
1867 Print internal disassembler information about instruction at a given address.
1871 set disassembler-options
1872 show disassembler-options
1873 Controls the passing of target specific information to the disassembler.
1874 If it is necessary to specify more than one disassembler option then
1875 multiple options can be placed together into a comma separated list.
1876 The default value is the empty string. Currently, the only supported
1877 targets are ARM, PowerPC and S/390.
1882 Erases all the flash memory regions reported by the target. This is
1883 equivalent to the CLI command flash-erase.
1885 -file-list-shared-libraries
1886 List the shared libraries in the program. This is
1887 equivalent to the CLI command "info shared".
1890 Catchpoints stopping the program when Ada exceptions are
1891 handled. This is equivalent to the CLI command "catch handlers".
1893 *** Changes in GDB 7.12
1895 * GDB and GDBserver now build with a C++ compiler by default.
1897 The --enable-build-with-cxx configure option is now enabled by
1898 default. One must now explicitly configure with
1899 --disable-build-with-cxx in order to build with a C compiler. This
1900 option will be removed in a future release.
1902 * GDBserver now supports recording btrace without maintaining an active
1905 * GDB now supports a negative repeat count in the 'x' command to examine
1906 memory backward from the given address. For example:
1909 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1910 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1911 (gdb) x/-5i 0x0000000000400580
1912 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1913 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1914 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1915 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1916 0x40057b <main(int, char**)+25>:
1917 callq 0x400536 <Func1(int, char const*)>
1919 * Fortran: Support structures with fields of dynamic types and
1920 arrays of dynamic types.
1922 * The symbol dumping maintenance commands have new syntax.
1923 maint print symbols [-pc address] [--] [filename]
1924 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1925 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1926 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1927 maint print msymbols [-objfile objfile] [--] [filename]
1929 * GDB now supports multibit bitfields and enums in target register
1932 * New Python-based convenience function $_as_string(val), which returns
1933 the textual representation of a value. This function is especially
1934 useful to obtain the text label of an enum value.
1936 * Intel MPX bound violation handling.
1938 Segmentation faults caused by a Intel MPX boundary violation
1939 now display the kind of violation (upper or lower), the memory
1940 address accessed and the memory bounds, along with the usual
1941 signal received and code location.
1945 Program received signal SIGSEGV, Segmentation fault
1946 Upper bound violation while accessing address 0x7fffffffc3b3
1947 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1948 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1950 * Rust language support.
1951 GDB now supports debugging programs written in the Rust programming
1952 language. See https://www.rust-lang.org/ for more information about
1955 * Support for running interpreters on specified input/output devices
1957 GDB now supports a new mechanism that allows frontends to provide
1958 fully featured GDB console views, as a better alternative to
1959 building such views on top of the "-interpreter-exec console"
1960 command. See the new "new-ui" command below. With that command,
1961 frontends can now start GDB in the traditional command-line mode
1962 running in an embedded terminal emulator widget, and create a
1963 separate MI interpreter running on a specified i/o device. In this
1964 way, GDB handles line editing, history, tab completion, etc. in the
1965 console all by itself, and the GUI uses the separate MI interpreter
1966 for its own control and synchronization, invisible to the command
1969 * The "catch syscall" command catches groups of related syscalls.
1971 The "catch syscall" command now supports catching a group of related
1972 syscalls using the 'group:' or 'g:' prefix.
1977 skip -gfile file-glob-pattern
1978 skip -function function
1979 skip -rfunction regular-expression
1980 A generalized form of the skip command, with new support for
1981 glob-style file names and regular expressions for function names.
1982 Additionally, a file spec and a function spec may now be combined.
1984 maint info line-table REGEXP
1985 Display the contents of GDB's internal line table data structure.
1988 Run any GDB unit tests that were compiled in.
1991 Start a new user interface instance running INTERP as interpreter,
1992 using the TTY file for input/output.
1996 ** gdb.Breakpoint objects have a new attribute "pending", which
1997 indicates whether the breakpoint is pending.
1998 ** Three new breakpoint-related events have been added:
1999 gdb.breakpoint_created, gdb.breakpoint_modified, and
2000 gdb.breakpoint_deleted.
2002 signal-event EVENTID
2003 Signal ("set") the given MS-Windows event object. This is used in
2004 conjunction with the Windows JIT debugging (AeDebug) support, where
2005 the OS suspends a crashing process until a debugger can attach to
2006 it. Resuming the crashing process, in order to debug it, is done by
2007 signalling an event.
2009 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2010 was added in GDBserver, including JIT compiling fast tracepoint's
2011 conditional expression bytecode into native code.
2013 * Support for various remote target protocols and ROM monitors has
2016 target m32rsdi Remote M32R debugging over SDI
2017 target mips MIPS remote debugging protocol
2018 target pmon PMON ROM monitor
2019 target ddb NEC's DDB variant of PMON for Vr4300
2020 target rockhopper NEC RockHopper variant of PMON
2021 target lsi LSI variant of PMO
2023 * Support for tracepoints and fast tracepoints on powerpc-linux,
2024 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2025 including JIT compiling fast tracepoint's conditional expression
2026 bytecode into native code.
2028 * MI async record =record-started now includes the method and format used for
2029 recording. For example:
2031 =record-started,thread-group="i1",method="btrace",format="bts"
2033 * MI async record =thread-selected now includes the frame field. For example:
2035 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2039 Andes NDS32 nds32*-*-elf
2041 *** Changes in GDB 7.11
2043 * GDB now supports debugging kernel-based threads on FreeBSD.
2045 * Per-inferior thread numbers
2047 Thread numbers are now per inferior instead of global. If you're
2048 debugging multiple inferiors, GDB displays thread IDs using a
2049 qualified INF_NUM.THR_NUM form. For example:
2053 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2054 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2055 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2056 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2058 As consequence, thread numbers as visible in the $_thread
2059 convenience variable and in Python's InferiorThread.num attribute
2060 are no longer unique between inferiors.
2062 GDB now maintains a second thread ID per thread, referred to as the
2063 global thread ID, which is the new equivalent of thread numbers in
2064 previous releases. See also $_gthread below.
2066 For backwards compatibility, MI's thread IDs always refer to global
2069 * Commands that accept thread IDs now accept the qualified
2070 INF_NUM.THR_NUM form as well. For example:
2073 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2076 * In commands that accept a list of thread IDs, you can now refer to
2077 all threads of an inferior using a star wildcard. GDB accepts
2078 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2079 refer to all threads of the current inferior. For example, "info
2082 * You can use "info threads -gid" to display the global thread ID of
2085 * The new convenience variable $_gthread holds the global number of
2088 * The new convenience variable $_inferior holds the number of the
2091 * GDB now displays the ID and name of the thread that hit a breakpoint
2092 or received a signal, if your program is multi-threaded. For
2095 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2096 Thread 1 "main" received signal SIGINT, Interrupt.
2098 * Record btrace now supports non-stop mode.
2100 * Support for tracepoints on aarch64-linux was added in GDBserver.
2102 * The 'record instruction-history' command now indicates speculative execution
2103 when using the Intel Processor Trace recording format.
2105 * GDB now allows users to specify explicit locations, bypassing
2106 the linespec parser. This feature is also available to GDB/MI
2109 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2110 GDB now is able to debug both AArch64 applications and ARM applications
2113 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2114 including JIT compiling fast tracepoint's conditional expression bytecode
2117 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2119 * "info threads", "info inferiors", "info display", "info checkpoints"
2120 and "maint info program-spaces" now list the corresponding items in
2121 ascending ID order, for consistency with all other "info" commands.
2123 * In Ada, the overloads selection menu has been enhanced to display the
2124 parameter types and the return types for the matching overloaded subprograms.
2128 maint set target-non-stop (on|off|auto)
2129 maint show target-non-stop
2130 Control whether GDB targets always operate in non-stop mode even if
2131 "set non-stop" is "off". The default is "auto", meaning non-stop
2132 mode is enabled if supported by the target.
2134 maint set bfd-sharing
2135 maint show bfd-sharing
2136 Control the reuse of bfd objects.
2139 show debug bfd-cache
2140 Control display of debugging info regarding bfd caching.
2144 Control display of debugging info regarding FreeBSD threads.
2146 set remote multiprocess-extensions-packet
2147 show remote multiprocess-extensions-packet
2148 Set/show the use of the remote protocol multiprocess extensions.
2150 set remote thread-events
2151 show remote thread-events
2152 Set/show the use of thread create/exit events.
2154 set ada print-signatures on|off
2155 show ada print-signatures"
2156 Control whether parameter types and return types are displayed in overloads
2157 selection menus. It is activated (@code{on}) by default.
2161 Controls the maximum size of memory, in bytes, that GDB will
2162 allocate for value contents. Prevents incorrect programs from
2163 causing GDB to allocate overly large buffers. Default is 64k.
2165 * The "disassemble" command accepts a new modifier: /s.
2166 It prints mixed source+disassembly like /m with two differences:
2167 - disassembled instructions are now printed in program order, and
2168 - and source for all relevant files is now printed.
2169 The "/m" option is now considered deprecated: its "source-centric"
2170 output hasn't proved useful in practice.
2172 * The "record instruction-history" command accepts a new modifier: /s.
2173 It behaves exactly like /m and prints mixed source+disassembly.
2175 * The "set scheduler-locking" command supports a new mode "replay".
2176 It behaves like "off" in record mode and like "on" in replay mode.
2178 * Support for various ROM monitors has been removed:
2180 target dbug dBUG ROM monitor for Motorola ColdFire
2181 target picobug Motorola picobug monitor
2182 target dink32 DINK32 ROM monitor for PowerPC
2183 target m32r Renesas M32R/D ROM monitor
2184 target mon2000 mon2000 ROM monitor
2185 target ppcbug PPCBUG ROM monitor for PowerPC
2187 * Support for reading/writing memory and extracting values on architectures
2188 whose memory is addressable in units of any integral multiple of 8 bits.
2191 Allows to break when an Ada exception is handled.
2193 * New remote packets
2196 Indicates that an exec system call was executed.
2198 exec-events feature in qSupported
2199 The qSupported packet allows GDB to request support for exec
2200 events using the new 'gdbfeature' exec-event, and the qSupported
2201 response can contain the corresponding 'stubfeature'. Set and
2202 show commands can be used to display whether these features are enabled.
2205 Equivalent to interrupting with the ^C character, but works in
2208 thread created stop reason (T05 create:...)
2209 Indicates that the thread was just created and is stopped at entry.
2211 thread exit stop reply (w exitcode;tid)
2212 Indicates that the thread has terminated.
2215 Enables/disables thread create and exit event reporting. For
2216 example, this is used in non-stop mode when GDB stops a set of
2217 threads and synchronously waits for the their corresponding stop
2218 replies. Without exit events, if one of the threads exits, GDB
2219 would hang forever not knowing that it should no longer expect a
2220 stop for that same thread.
2223 Indicates that there are no resumed threads left in the target (all
2224 threads are stopped). The remote stub reports support for this stop
2225 reply to GDB's qSupported query.
2228 Enables/disables catching syscalls from the inferior process.
2229 The remote stub reports support for this packet to GDB's qSupported query.
2231 syscall_entry stop reason
2232 Indicates that a syscall was just called.
2234 syscall_return stop reason
2235 Indicates that a syscall just returned.
2237 * Extended-remote exec events
2239 ** GDB now has support for exec events on extended-remote Linux targets.
2240 For such targets with Linux kernels 2.5.46 and later, this enables
2241 follow-exec-mode and exec catchpoints.
2243 set remote exec-event-feature-packet
2244 show remote exec-event-feature-packet
2245 Set/show the use of the remote exec event feature.
2247 * Thread names in remote protocol
2249 The reply to qXfer:threads:read may now include a name attribute for each
2252 * Target remote mode fork and exec events
2254 ** GDB now has support for fork and exec events on target remote mode
2255 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2256 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2257 fork and exec catchpoints.
2259 * Remote syscall events
2261 ** GDB now has support for catch syscall on remote Linux targets,
2262 currently enabled on x86/x86_64 architectures.
2264 set remote catch-syscall-packet
2265 show remote catch-syscall-packet
2266 Set/show the use of the remote catch syscall feature.
2270 ** The -var-set-format command now accepts the zero-hexadecimal
2271 format. It outputs data in hexadecimal format with zero-padding on the
2276 ** gdb.InferiorThread objects have a new attribute "global_num",
2277 which refers to the thread's global thread ID. The existing
2278 "num" attribute now refers to the thread's per-inferior number.
2279 See "Per-inferior thread numbers" above.
2280 ** gdb.InferiorThread objects have a new attribute "inferior", which
2281 is the Inferior object the thread belongs to.
2283 *** Changes in GDB 7.10
2285 * Support for process record-replay and reverse debugging on aarch64*-linux*
2286 targets has been added. GDB now supports recording of A64 instruction set
2287 including advance SIMD instructions.
2289 * Support for Sun's version of the "stabs" debug file format has been removed.
2291 * GDB now honors the content of the file /proc/PID/coredump_filter
2292 (PID is the process ID) on GNU/Linux systems. This file can be used
2293 to specify the types of memory mappings that will be included in a
2294 corefile. For more information, please refer to the manual page of
2295 "core(5)". GDB also has a new command: "set use-coredump-filter
2296 on|off". It allows to set whether GDB will read the content of the
2297 /proc/PID/coredump_filter file when generating a corefile.
2299 * The "info os" command on GNU/Linux can now display information on
2301 "info os cpus" Listing of all cpus/cores on the system
2303 * GDB has two new commands: "set serial parity odd|even|none" and
2304 "show serial parity". These allows to set or show parity for the
2307 * The "info source" command now displays the producer string if it was
2308 present in the debug info. This typically includes the compiler version
2309 and may include things like its command line arguments.
2311 * The "info dll", an alias of the "info sharedlibrary" command,
2312 is now available on all platforms.
2314 * Directory names supplied to the "set sysroot" commands may be
2315 prefixed with "target:" to tell GDB to access shared libraries from
2316 the target system, be it local or remote. This replaces the prefix
2317 "remote:". The default sysroot has been changed from "" to
2318 "target:". "remote:" is automatically converted to "target:" for
2319 backward compatibility.
2321 * The system root specified by "set sysroot" will be prepended to the
2322 filename of the main executable (if reported to GDB as absolute by
2323 the operating system) when starting processes remotely, and when
2324 attaching to already-running local or remote processes.
2326 * GDB now supports automatic location and retrieval of executable
2327 files from remote targets. Remote debugging can now be initiated
2328 using only a "target remote" or "target extended-remote" command
2329 (no "set sysroot" or "file" commands are required). See "New remote
2332 * The "dump" command now supports verilog hex format.
2334 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2336 * On GNU/Linux, GDB and gdbserver are now able to access executable
2337 and shared library files without a "set sysroot" command when
2338 attaching to processes running in different mount namespaces from
2339 the debugger. This makes it possible to attach to processes in
2340 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2341 See "New remote packets" below.
2343 * The "tui reg" command now provides completion for all of the
2344 available register groups, including target specific groups.
2346 * The HISTSIZE environment variable is no longer read when determining
2347 the size of GDB's command history. GDB now instead reads the dedicated
2348 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2349 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2354 ** Memory ports can now be unbuffered.
2358 ** gdb.Objfile objects have a new attribute "username",
2359 which is the name of the objfile as specified by the user,
2360 without, for example, resolving symlinks.
2361 ** You can now write frame unwinders in Python.
2362 ** gdb.Type objects have a new method "optimized_out",
2363 returning optimized out gdb.Value instance of this type.
2364 ** gdb.Value objects have new methods "reference_value" and
2365 "const_value" which return a reference to the value and a
2366 "const" version of the value respectively.
2370 maint print symbol-cache
2371 Print the contents of the symbol cache.
2373 maint print symbol-cache-statistics
2374 Print statistics of symbol cache usage.
2376 maint flush-symbol-cache
2377 Flush the contents of the symbol cache.
2381 Start branch trace recording using Branch Trace Store (BTS) format.
2384 Evaluate expression by using the compiler and print result.
2388 Explicit commands for enabling and disabling tui mode.
2391 set mpx bound on i386 and amd64
2392 Support for bound table investigation on Intel MPX enabled applications.
2396 Start branch trace recording using Intel Processor Trace format.
2399 Print information about branch tracing internals.
2401 maint btrace packet-history
2402 Print the raw branch tracing data.
2404 maint btrace clear-packet-history
2405 Discard the stored raw branch tracing data.
2408 Discard all branch tracing data. It will be fetched and processed
2409 anew by the next "record" command.
2414 Renamed from "set debug dwarf2-die".
2415 show debug dwarf-die
2416 Renamed from "show debug dwarf2-die".
2418 set debug dwarf-read
2419 Renamed from "set debug dwarf2-read".
2420 show debug dwarf-read
2421 Renamed from "show debug dwarf2-read".
2423 maint set dwarf always-disassemble
2424 Renamed from "maint set dwarf2 always-disassemble".
2425 maint show dwarf always-disassemble
2426 Renamed from "maint show dwarf2 always-disassemble".
2428 maint set dwarf max-cache-age
2429 Renamed from "maint set dwarf2 max-cache-age".
2430 maint show dwarf max-cache-age
2431 Renamed from "maint show dwarf2 max-cache-age".
2433 set debug dwarf-line
2434 show debug dwarf-line
2435 Control display of debugging info regarding DWARF line processing.
2438 show max-completions
2439 Set the maximum number of candidates to be considered during
2440 completion. The default value is 200. This limit allows GDB
2441 to avoid generating large completion lists, the computation of
2442 which can cause the debugger to become temporarily unresponsive.
2444 set history remove-duplicates
2445 show history remove-duplicates
2446 Control the removal of duplicate history entries.
2448 maint set symbol-cache-size
2449 maint show symbol-cache-size
2450 Control the size of the symbol cache.
2452 set|show record btrace bts buffer-size
2453 Set and show the size of the ring buffer used for branch tracing in
2455 The obtained size may differ from the requested size. Use "info
2456 record" to see the obtained buffer size.
2458 set debug linux-namespaces
2459 show debug linux-namespaces
2460 Control display of debugging info regarding Linux namespaces.
2462 set|show record btrace pt buffer-size
2463 Set and show the size of the ring buffer used for branch tracing in
2464 Intel Processor Trace format.
2465 The obtained size may differ from the requested size. Use "info
2466 record" to see the obtained buffer size.
2468 maint set|show btrace pt skip-pad
2469 Set and show whether PAD packets are skipped when computing the
2472 * The command 'thread apply all' can now support new option '-ascending'
2473 to call its specified command for all threads in ascending order.
2475 * Python/Guile scripting
2477 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2478 special section named `.debug_gdb_scripts'.
2480 * New remote packets
2482 qXfer:btrace-conf:read
2483 Return the branch trace configuration for the current thread.
2485 Qbtrace-conf:bts:size
2486 Set the requested ring buffer size for branch tracing in BTS format.
2489 Enable Intel Processor Trace-based branch tracing for the current
2490 process. The remote stub reports support for this packet to GDB's
2493 Qbtrace-conf:pt:size
2494 Set the requested ring buffer size for branch tracing in Intel Processor
2498 Indicates a memory breakpoint instruction was executed, irrespective
2499 of whether it was GDB that planted the breakpoint or the breakpoint
2500 is hardcoded in the program. This is required for correct non-stop
2504 Indicates the target stopped for a hardware breakpoint. This is
2505 required for correct non-stop mode operation.
2508 Return information about files on the remote system.
2510 qXfer:exec-file:read
2511 Return the full absolute name of the file that was executed to
2512 create a process running on the remote system.
2515 Select the filesystem on which vFile: operations with filename
2516 arguments will operate. This is required for GDB to be able to
2517 access files on remote targets where the remote stub does not
2518 share a common filesystem with the inferior(s).
2521 Indicates that a fork system call was executed.
2524 Indicates that a vfork system call was executed.
2526 vforkdone stop reason
2527 Indicates that a vfork child of the specified process has executed
2528 an exec or exit, allowing the vfork parent to resume execution.
2530 fork-events and vfork-events features in qSupported
2531 The qSupported packet allows GDB to request support for fork and
2532 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2533 and the qSupported response can contain the corresponding
2534 'stubfeatures'. Set and show commands can be used to display
2535 whether these features are enabled.
2537 * Extended-remote fork events
2539 ** GDB now has support for fork events on extended-remote Linux
2540 targets. For targets with Linux kernels 2.5.60 and later, this
2541 enables follow-fork-mode and detach-on-fork for both fork and
2542 vfork, as well as fork and vfork catchpoints.
2544 * The info record command now shows the recording format and the
2545 branch tracing configuration for the current thread when using
2546 the btrace record target.
2547 For the BTS format, it shows the ring buffer size.
2549 * GDB now has support for DTrace USDT (Userland Static Defined
2550 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2552 * GDB now supports access to vector registers on S/390 GNU/Linux
2555 * Removed command line options
2557 -xdb HP-UX XDB compatibility mode.
2559 * Removed targets and native configurations
2561 HP/PA running HP-UX hppa*-*-hpux*
2562 Itanium running HP-UX ia64-*-hpux*
2564 * New configure options
2567 This configure option allows the user to build GDB with support for
2568 Intel Processor Trace (default: auto). This requires libipt.
2570 --with-libipt-prefix=PATH
2571 Specify the path to the version of libipt that GDB should use.
2572 $PATH/include should contain the intel-pt.h header and
2573 $PATH/lib should contain the libipt.so library.
2575 *** Changes in GDB 7.9.1
2579 ** Xmethods can now specify a result type.
2581 *** Changes in GDB 7.9
2583 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2587 ** You can now access frame registers from Python scripts.
2588 ** New attribute 'producer' for gdb.Symtab objects.
2589 ** gdb.Objfile objects have a new attribute "progspace",
2590 which is the gdb.Progspace object of the containing program space.
2591 ** gdb.Objfile objects have a new attribute "owner".
2592 ** gdb.Objfile objects have a new attribute "build_id",
2593 which is the build ID generated when the file was built.
2594 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2595 ** A new event "gdb.clear_objfiles" has been added, triggered when
2596 selecting a new file to debug.
2597 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2598 ** New function gdb.lookup_objfile.
2600 New events which are triggered when GDB modifies the state of the
2603 ** gdb.events.inferior_call_pre: Function call is about to be made.
2604 ** gdb.events.inferior_call_post: Function call has just been made.
2605 ** gdb.events.memory_changed: A memory location has been altered.
2606 ** gdb.events.register_changed: A register has been altered.
2608 * New Python-based convenience functions:
2610 ** $_caller_is(name [, number_of_frames])
2611 ** $_caller_matches(regexp [, number_of_frames])
2612 ** $_any_caller_is(name [, number_of_frames])
2613 ** $_any_caller_matches(regexp [, number_of_frames])
2615 * GDB now supports the compilation and injection of source code into
2616 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2617 to compile the source code to object code, and if successful, inject
2618 and execute that code within the current context of the inferior.
2619 Currently the C language is supported. The commands used to
2620 interface with this new feature are:
2622 compile code [-raw|-r] [--] [source code]
2623 compile file [-raw|-r] filename
2627 demangle [-l language] [--] name
2628 Demangle "name" in the specified language, or the current language
2629 if elided. This command is renamed from the "maint demangle" command.
2630 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2631 as "maint demangler-warning".
2633 queue-signal signal-name-or-number
2634 Queue a signal to be delivered to the thread when it is resumed.
2636 add-auto-load-scripts-directory directory
2637 Add entries to the list of directories from which to load auto-loaded
2640 maint print user-registers
2641 List all currently available "user" registers.
2643 compile code [-r|-raw] [--] [source code]
2644 Compile, inject, and execute in the inferior the executable object
2645 code produced by compiling the provided source code.
2647 compile file [-r|-raw] filename
2648 Compile and inject into the inferior the executable object code
2649 produced by compiling the source code stored in the filename
2652 * On resume, GDB now always passes the signal the program had stopped
2653 for to the thread the signal was sent to, even if the user changed
2654 threads before resuming. Previously GDB would often (but not
2655 always) deliver the signal to the thread that happens to be current
2658 * Conversely, the "signal" command now consistently delivers the
2659 requested signal to the current thread. GDB now asks for
2660 confirmation if the program had stopped for a signal and the user
2661 switched threads meanwhile.
2663 * "breakpoint always-inserted" modes "off" and "auto" merged.
2665 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2666 won't remove breakpoints from the target until all threads stop,
2667 even in non-stop mode. The "auto" mode has been removed, and "off"
2668 is now the default mode.
2672 set debug symbol-lookup
2673 show debug symbol-lookup
2674 Control display of debugging info regarding symbol lookup.
2678 ** The -list-thread-groups command outputs an exit-code field for
2679 inferiors that have exited.
2683 MIPS SDE mips*-sde*-elf*
2687 Support for these obsolete configurations has been removed.
2689 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2690 SGI Irix-5.x mips-*-irix5*
2691 SGI Irix-6.x mips-*-irix6*
2692 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2693 VAX running Ultrix vax-*-ultrix*
2695 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2696 and "assf"), have been removed. Use the "sharedlibrary" command, or
2697 its alias "share", instead.
2699 *** Changes in GDB 7.8
2701 * New command line options
2704 This is an alias for the --data-directory option.
2706 * GDB supports printing and modifying of variable length automatic arrays
2707 as specified in ISO C99.
2709 * The ARM simulator now supports instruction level tracing
2710 with or without disassembly.
2714 GDB now has support for scripting using Guile. Whether this is
2715 available is determined at configure time.
2716 Guile version 2.0 or greater is required.
2717 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2719 * New commands (for set/show, see "New options" below)
2723 Invoke CODE by passing it to the Guile interpreter.
2727 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2729 info auto-load guile-scripts [regexp]
2730 Print the list of automatically loaded Guile scripts.
2732 * The source command is now capable of sourcing Guile scripts.
2733 This feature is dependent on the debugger being built with Guile support.
2737 set print symbol-loading (off|brief|full)
2738 show print symbol-loading
2739 Control whether to print informational messages when loading symbol
2740 information for a file. The default is "full", but when debugging
2741 programs with large numbers of shared libraries the amount of output
2742 becomes less useful.
2744 set guile print-stack (none|message|full)
2745 show guile print-stack
2746 Show a stack trace when an error is encountered in a Guile script.
2748 set auto-load guile-scripts (on|off)
2749 show auto-load guile-scripts
2750 Control auto-loading of Guile script files.
2752 maint ada set ignore-descriptive-types (on|off)
2753 maint ada show ignore-descriptive-types
2754 Control whether the debugger should ignore descriptive types in Ada
2755 programs. The default is not to ignore the descriptive types. See
2756 the user manual for more details on descriptive types and the intended
2757 usage of this option.
2759 set auto-connect-native-target
2761 Control whether GDB is allowed to automatically connect to the
2762 native target for the run, attach, etc. commands when not connected
2763 to any target yet. See also "target native" below.
2765 set record btrace replay-memory-access (read-only|read-write)
2766 show record btrace replay-memory-access
2767 Control what memory accesses are allowed during replay.
2769 maint set target-async (on|off)
2770 maint show target-async
2771 This controls whether GDB targets operate in synchronous or
2772 asynchronous mode. Normally the default is asynchronous, if it is
2773 available; but this can be changed to more easily debug problems
2774 occurring only in synchronous mode.
2776 set mi-async (on|off)
2778 Control whether MI asynchronous mode is preferred. This supersedes
2779 "set target-async" of previous GDB versions.
2781 * "set target-async" is deprecated as a CLI option and is now an alias
2782 for "set mi-async" (only puts MI into async mode).
2784 * Background execution commands (e.g., "c&", "s&", etc.) are now
2785 possible ``out of the box'' if the target supports them. Previously
2786 the user would need to explicitly enable the possibility with the
2787 "set target-async on" command.
2789 * New features in the GDB remote stub, GDBserver
2791 ** New option --debug-format=option1[,option2,...] allows one to add
2792 additional text to each output. At present only timestamps
2793 are supported: --debug-format=timestamps.
2794 Timestamps can also be turned on with the
2795 "monitor set debug-format timestamps" command from GDB.
2797 * The 'record instruction-history' command now starts counting instructions
2798 at one. This also affects the instruction ranges reported by the
2799 'record function-call-history' command when given the /i modifier.
2801 * The command 'record function-call-history' supports a new modifier '/c' to
2802 indent the function names based on their call stack depth.
2803 The fields for the '/i' and '/l' modifier have been reordered.
2804 The source line range is now prefixed with 'at'.
2805 The instruction range is now prefixed with 'inst'.
2806 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2807 "record instruction-history" and "list" commands.
2809 * The ranges given as arguments to the 'record function-call-history' and
2810 'record instruction-history' commands are now inclusive.
2812 * The btrace record target now supports the 'record goto' command.
2813 For locations inside the execution trace, the back trace is computed
2814 based on the information stored in the execution trace.
2816 * The btrace record target supports limited reverse execution and replay.
2817 The target does not record data and therefore does not allow reading
2818 memory or registers.
2820 * The "catch syscall" command now works on s390*-linux* targets.
2822 * The "compare-sections" command is no longer specific to target
2823 remote. It now works with all targets.
2825 * All native targets are now consistently called "native".
2826 Consequently, the "target child", "target GNU", "target djgpp",
2827 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2828 commands have been replaced with "target native". The QNX/NTO port
2829 leaves the "procfs" target in place and adds a "native" target for
2830 consistency with other ports. The impact on users should be minimal
2831 as these commands previously either throwed an error, or were
2832 no-ops. The target's name is visible in the output of the following
2833 commands: "help target", "info target", "info files", "maint print
2836 * The "target native" command now connects to the native target. This
2837 can be used to launch native programs even when "set
2838 auto-connect-native-target" is set to off.
2840 * GDB now supports access to Intel MPX registers on GNU/Linux.
2842 * Support for Intel AVX-512 registers on GNU/Linux.
2843 Support displaying and modifying Intel AVX-512 registers
2844 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2846 * New remote packets
2848 qXfer:btrace:read's annex
2849 The qXfer:btrace:read packet supports a new annex 'delta' to read
2850 branch trace incrementally.
2854 ** Valid Python operations on gdb.Value objects representing
2855 structs/classes invoke the corresponding overloaded operators if
2857 ** New `Xmethods' feature in the Python API. Xmethods are
2858 additional methods or replacements for existing methods of a C++
2859 class. This feature is useful for those cases where a method
2860 defined in C++ source code could be inlined or optimized out by
2861 the compiler, making it unavailable to GDB.
2864 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2866 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2867 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2868 its alias "share", instead.
2870 * The commands "set remotebaud" and "show remotebaud" are no longer
2871 supported. Use "set serial baud" and "show serial baud" (respectively)
2876 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2877 target-async". The latter is left as a deprecated alias of the
2878 former for backward compatibility. If the target supports it,
2879 CLI background execution commands are now always possible by
2880 default, independently of whether the frontend stated a
2881 preference for asynchronous execution with "-gdb-set mi-async".
2882 Previously "-gdb-set target-async off" affected both MI execution
2883 commands and CLI execution commands.
2885 *** Changes in GDB 7.7
2887 * Improved support for process record-replay and reverse debugging on
2888 arm*-linux* targets. Support for thumb32 and syscall instruction
2889 recording has been added.
2891 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2893 * GDB now supports Fission DWP file format version 2.
2894 http://gcc.gnu.org/wiki/DebugFission
2896 * New convenience function "$_isvoid", to check whether an expression
2897 is void. A void expression is an expression where the type of the
2898 result is "void". For example, some convenience variables may be
2899 "void" when evaluated (e.g., "$_exitcode" before the execution of
2900 the program being debugged; or an undefined convenience variable).
2901 Another example, when calling a function whose return type is
2904 * The "maintenance print objfiles" command now takes an optional regexp.
2906 * The "catch syscall" command now works on arm*-linux* targets.
2908 * GDB now consistently shows "<not saved>" when printing values of
2909 registers the debug info indicates have not been saved in the frame
2910 and there's nowhere to retrieve them from
2911 (callee-saved/call-clobbered registers):
2916 (gdb) info registers rax
2919 Before, the former would print "<optimized out>", and the latter
2920 "*value not available*".
2922 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2927 ** Frame filters and frame decorators have been added.
2928 ** Temporary breakpoints are now supported.
2929 ** Line tables representation has been added.
2930 ** New attribute 'parent_type' for gdb.Field objects.
2931 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2932 ** New attribute 'name' for gdb.Type objects.
2936 Nios II ELF nios2*-*-elf
2937 Nios II GNU/Linux nios2*-*-linux
2938 Texas Instruments MSP430 msp430*-*-elf
2940 * Removed native configurations
2942 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2943 been removed. ELF variants of these configurations are kept supported.
2945 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2946 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2947 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2948 i[34567]86-*-openbsd3.[0-3]
2949 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2950 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2951 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2955 Like "catch throw", but catches a re-thrown exception.
2956 maint check-psymtabs
2957 Renamed from old "maint check-symtabs".
2959 Perform consistency checks on symtabs.
2960 maint expand-symtabs
2961 Expand symtabs matching an optional regexp.
2964 Display the details of GDB configure-time options.
2966 maint set|show per-command
2967 maint set|show per-command space
2968 maint set|show per-command time
2969 maint set|show per-command symtab
2970 Enable display of per-command gdb resource usage.
2972 remove-symbol-file FILENAME
2973 remove-symbol-file -a ADDRESS
2974 Remove a symbol file added via add-symbol-file. The file to remove
2975 can be identified by its filename or by an address that lies within
2976 the boundaries of this symbol file in memory.
2979 info exceptions REGEXP
2980 Display the list of Ada exceptions defined in the program being
2981 debugged. If provided, only the exceptions whose names match REGEXP
2986 set debug symfile off|on
2988 Control display of debugging info regarding reading symbol files and
2989 symbol tables within those files
2991 set print raw frame-arguments
2992 show print raw frame-arguments
2993 Set/show whether to print frame arguments in raw mode,
2994 disregarding any defined pretty-printers.
2996 set remote trace-status-packet
2997 show remote trace-status-packet
2998 Set/show the use of remote protocol qTStatus packet.
3002 Control display of debugging messages related to Nios II targets.
3006 Control whether target-assisted range stepping is enabled.
3008 set startup-with-shell
3009 show startup-with-shell
3010 Specifies whether Unix child processes are started via a shell or
3015 Use the target memory cache for accesses to the code segment. This
3016 improves performance of remote debugging (particularly disassembly).
3018 * You can now use a literal value 'unlimited' for options that
3019 interpret 0 or -1 as meaning "unlimited". E.g., "set
3020 trace-buffer-size unlimited" is now an alias for "set
3021 trace-buffer-size -1" and "set height unlimited" is now an alias for
3024 * The "set debug symtab-create" debugging option of GDB has been changed to
3025 accept a verbosity level. 0 means "off", 1 provides basic debugging
3026 output, and values of 2 or greater provides more verbose output.
3028 * New command-line options
3030 Display the details of GDB configure-time options.
3032 * The command 'tsave' can now support new option '-ctf' to save trace
3033 buffer in Common Trace Format.
3035 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3038 * GDB now implements the C++ 'typeid' operator.
3040 * The new convenience variable $_exception holds the exception being
3041 thrown or caught at an exception-related catchpoint.
3043 * The exception-related catchpoints, like "catch throw", now accept a
3044 regular expression which can be used to filter exceptions by type.
3046 * The new convenience variable $_exitsignal is automatically set to
3047 the terminating signal number when the program being debugged dies
3048 due to an uncaught signal.
3052 ** All MI commands now accept an optional "--language" option.
3053 Support for this feature can be verified by using the "-list-features"
3054 command, which should contain "language-option".
3056 ** The new command -info-gdb-mi-command allows the user to determine
3057 whether a GDB/MI command is supported or not.
3059 ** The "^error" result record returned when trying to execute an undefined
3060 GDB/MI command now provides a variable named "code" whose content is the
3061 "undefined-command" error code. Support for this feature can be verified
3062 by using the "-list-features" command, which should contain
3063 "undefined-command-error-code".
3065 ** The -trace-save MI command can optionally save trace buffer in Common
3068 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3070 ** The command -data-list-register-values now accepts an optional
3071 "--skip-unavailable" option. When used, only the available registers
3074 ** The new command -trace-frame-collected dumps collected variables,
3075 computed expressions, tvars, memory and registers in a traceframe.
3077 ** The commands -stack-list-locals, -stack-list-arguments and
3078 -stack-list-variables now accept an option "--skip-unavailable".
3079 When used, only the available locals or arguments are displayed.
3081 ** The -exec-run command now accepts an optional "--start" option.
3082 When used, the command follows the same semantics as the "start"
3083 command, stopping the program's execution at the start of its
3084 main subprogram. Support for this feature can be verified using
3085 the "-list-features" command, which should contain
3086 "exec-run-start-option".
3088 ** The new commands -catch-assert and -catch-exceptions insert
3089 catchpoints stopping the program when Ada exceptions are raised.
3091 ** The new command -info-ada-exceptions provides the equivalent of
3092 the new "info exceptions" command.
3094 * New system-wide configuration scripts
3095 A GDB installation now provides scripts suitable for use as system-wide
3096 configuration scripts for the following systems:
3100 * GDB now supports target-assigned range stepping with remote targets.
3101 This improves the performance of stepping source lines by reducing
3102 the number of control packets from/to GDB. See "New remote packets"
3105 * GDB now understands the element 'tvar' in the XML traceframe info.
3106 It has the id of the collected trace state variables.
3108 * On S/390 targets that provide the transactional-execution feature,
3109 the program interruption transaction diagnostic block (TDB) is now
3110 represented as a number of additional "registers" in GDB.
3112 * New remote packets
3116 The vCont packet supports a new 'r' action, that tells the remote
3117 stub to step through an address range itself, without GDB
3118 involvemement at each single-step.
3120 qXfer:libraries-svr4:read's annex
3121 The previously unused annex of the qXfer:libraries-svr4:read packet
3122 is now used to support passing an argument list. The remote stub
3123 reports support for this argument list to GDB's qSupported query.
3124 The defined arguments are "start" and "prev", used to reduce work
3125 necessary for library list updating, resulting in significant
3128 * New features in the GDB remote stub, GDBserver
3130 ** GDBserver now supports target-assisted range stepping. Currently
3131 enabled on x86/x86_64 GNU/Linux targets.
3133 ** GDBserver now adds element 'tvar' in the XML in the reply to
3134 'qXfer:traceframe-info:read'. It has the id of the collected
3135 trace state variables.
3137 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3140 * New 'z' formatter for printing and examining memory, this displays the
3141 value as hexadecimal zero padded on the left to the size of the type.
3143 * GDB can now use Windows x64 unwinding data.
3145 * The "set remotebaud" command has been replaced by "set serial baud".
3146 Similarly, "show remotebaud" has been replaced by "show serial baud".
3147 The "set remotebaud" and "show remotebaud" commands are still available
3148 to provide backward compatibility with older versions of GDB.
3150 *** Changes in GDB 7.6
3152 * Target record has been renamed to record-full.
3153 Record/replay is now enabled with the "record full" command.
3154 This also affects settings that are associated with full record/replay
3155 that have been moved from "set/show record" to "set/show record full":
3157 set|show record full insn-number-max
3158 set|show record full stop-at-limit
3159 set|show record full memory-query
3161 * A new record target "record-btrace" has been added. The new target
3162 uses hardware support to record the control-flow of a process. It
3163 does not support replaying the execution, but it implements the
3164 below new commands for investigating the recorded execution log.
3165 This new recording method can be enabled using:
3169 The "record-btrace" target is only available on Intel Atom processors
3170 and requires a Linux kernel 2.6.32 or later.
3172 * Two new commands have been added for record/replay to give information
3173 about the recorded execution without having to replay the execution.
3174 The commands are only supported by "record btrace".
3176 record instruction-history prints the execution history at
3177 instruction granularity
3179 record function-call-history prints the execution history at
3180 function granularity
3182 * New native configurations
3184 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3185 FreeBSD/powerpc powerpc*-*-freebsd
3186 x86_64/Cygwin x86_64-*-cygwin*
3187 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3191 ARM AArch64 aarch64*-*-elf
3192 ARM AArch64 GNU/Linux aarch64*-*-linux
3193 Lynx 178 PowerPC powerpc-*-lynx*178
3194 x86_64/Cygwin x86_64-*-cygwin*
3195 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3197 * If the configured location of system.gdbinit file (as given by the
3198 --with-system-gdbinit option at configure time) is in the
3199 data-directory (as specified by --with-gdb-datadir at configure
3200 time) or in one of its subdirectories, then GDB will look for the
3201 system-wide init file in the directory specified by the
3202 --data-directory command-line option.
3204 * New command line options:
3206 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3207 other initialization files, unlike -nx which disables all of them.
3209 * Removed command line options
3211 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3214 * The 'ptype' and 'whatis' commands now accept an argument to control
3217 * 'info proc' now works on some core files.
3221 ** Vectors can be created with gdb.Type.vector.
3223 ** Python's atexit.register now works in GDB.
3225 ** Types can be pretty-printed via a Python API.
3227 ** Python 3 is now supported (in addition to Python 2.4 or later)
3229 ** New class gdb.Architecture exposes GDB's internal representation
3230 of architecture in the Python API.
3232 ** New method Frame.architecture returns the gdb.Architecture object
3233 corresponding to the frame's architecture.
3235 * New Python-based convenience functions:
3237 ** $_memeq(buf1, buf2, length)
3238 ** $_streq(str1, str2)
3240 ** $_regex(str, regex)
3242 * The 'cd' command now defaults to using '~' (the home directory) if not
3245 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3246 default for GCC since November 2000.
3248 * The command 'forward-search' can now be abbreviated as 'fo'.
3250 * The command 'info tracepoints' can now display 'installed on target'
3251 or 'not installed on target' for each non-pending location of tracepoint.
3253 * New configure options
3255 --enable-libmcheck/--disable-libmcheck
3256 By default, development versions are built with -lmcheck on hosts
3257 that support it, in order to help track memory corruption issues.
3258 Release versions, on the other hand, are built without -lmcheck
3259 by default. The --enable-libmcheck/--disable-libmcheck configure
3260 options allow the user to override that default.
3261 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3262 This configure option allows the user to build GDB with
3263 libbabeltrace using which GDB can read Common Trace Format data.
3265 * New commands (for set/show, see "New options" below)
3268 Catch signals. This is similar to "handle", but allows commands and
3269 conditions to be attached.
3272 List the BFDs known to GDB.
3274 python-interactive [command]
3276 Start a Python interactive prompt, or evaluate the optional command
3277 and print the result of expressions.
3280 "py" is a new alias for "python".
3282 enable type-printer [name]...
3283 disable type-printer [name]...
3284 Enable or disable type printers.
3288 ** For the Renesas Super-H architecture, the "regs" command has been removed
3289 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3294 set print type methods (on|off)
3295 show print type methods
3296 Control whether method declarations are displayed by "ptype".
3297 The default is to show them.
3299 set print type typedefs (on|off)
3300 show print type typedefs
3301 Control whether typedef definitions are displayed by "ptype".
3302 The default is to show them.
3304 set filename-display basename|relative|absolute
3305 show filename-display
3306 Control the way in which filenames is displayed.
3307 The default is "relative", which preserves previous behavior.
3309 set trace-buffer-size
3310 show trace-buffer-size
3311 Request target to change the size of trace buffer.
3313 set remote trace-buffer-size-packet auto|on|off
3314 show remote trace-buffer-size-packet
3315 Control the use of the remote protocol `QTBuffer:size' packet.
3319 Control display of debugging messages related to ARM AArch64.
3322 set debug coff-pe-read
3323 show debug coff-pe-read
3324 Control display of debugging messages related to reading of COFF/PE
3329 Control display of debugging messages related to Mach-O symbols
3332 set debug notification
3333 show debug notification
3334 Control display of debugging info for async remote notification.
3338 ** Command parameter changes are now notified using new async record
3339 "=cmd-param-changed".
3340 ** Trace frame changes caused by command "tfind" are now notified using
3341 new async record "=traceframe-changed".
3342 ** The creation, deletion and modification of trace state variables
3343 are now notified using new async records "=tsv-created",
3344 "=tsv-deleted" and "=tsv-modified".
3345 ** The start and stop of process record are now notified using new
3346 async record "=record-started" and "=record-stopped".
3347 ** Memory changes are now notified using new async record
3349 ** The data-disassemble command response will include a "fullname" field
3350 containing the absolute file name when source has been requested.
3351 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3352 command, to allow pattern filling of memory areas.
3353 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3354 library load/unload events.
3355 ** The response to breakpoint commands and breakpoint async records
3356 includes an "installed" field containing a boolean state about each
3357 non-pending tracepoint location is whether installed on target or not.
3358 ** Output of the "-trace-status" command includes a "trace-file" field
3359 containing the name of the trace file being examined. This field is
3360 optional, and only present when examining a trace file.
3361 ** The "fullname" field is now always present along with the "file" field,
3362 even if the file cannot be found by GDB.
3364 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3365 You must have the LZMA library available when configuring GDB for this
3366 feature to be enabled. For more information, see:
3367 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3369 * New remote packets
3372 Set the size of trace buffer. The remote stub reports support for this
3373 packet to gdb's qSupported query.
3376 Enable Branch Trace Store (BTS)-based branch tracing for the current
3377 thread. The remote stub reports support for this packet to gdb's
3381 Disable branch tracing for the current thread. The remote stub reports
3382 support for this packet to gdb's qSupported query.
3385 Read the traced branches for the current thread. The remote stub
3386 reports support for this packet to gdb's qSupported query.
3388 *** Changes in GDB 7.5
3390 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3391 for more x32 ABI info.
3393 * GDB now supports access to MIPS DSP registers on Linux targets.
3395 * GDB now supports debugging microMIPS binaries.
3397 * The "info os" command on GNU/Linux can now display information on
3398 several new classes of objects managed by the operating system:
3399 "info os procgroups" lists process groups
3400 "info os files" lists file descriptors
3401 "info os sockets" lists internet-domain sockets
3402 "info os shm" lists shared-memory regions
3403 "info os semaphores" lists semaphores
3404 "info os msg" lists message queues
3405 "info os modules" lists loaded kernel modules
3407 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3408 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3409 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3410 options and inspect the probe arguments using the new $_probe_arg family
3411 of convenience variables. You can obtain more information about SystemTap
3412 in <http://sourceware.org/systemtap/>.
3414 * GDB now supports reversible debugging on ARM, it allows you to
3415 debug basic ARM and THUMB instructions, and provides
3416 record/replay support.
3418 * The option "symbol-reloading" has been deleted as it is no longer used.
3422 ** GDB commands implemented in Python can now be put in command class
3425 ** The "maint set python print-stack on|off" is now deleted.
3427 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3428 apply "flag enum"-style pretty-printing to any enum.
3430 ** gdb.lookup_symbol can now work when there is no current frame.
3432 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3433 the source at which the symbol was defined.
3435 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3436 method 'value'. The former indicates whether the symbol needs a
3437 frame in order to compute its value, and the latter computes the
3440 ** A new method 'referenced_value' on gdb.Value objects which can
3441 dereference pointer as well as C++ reference values.
3443 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3444 which return the global and static blocks (as gdb.Block objects),
3445 of the underlying symbol table, respectively.
3447 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3448 object associated with a PC value.
3450 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3451 of the address range occupied by code for the current source line.
3453 * Go language support.
3454 GDB now supports debugging programs written in the Go programming
3457 * GDBserver now supports stdio connections.
3458 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3460 * The binary "gdbtui" can no longer be built or installed.
3461 Use "gdb -tui" instead.
3463 * GDB will now print "flag" enums specially. A flag enum is one where
3464 all the enumerator values have no bits in common when pairwise
3465 "and"ed. When printing a value whose type is a flag enum, GDB will
3466 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3467 (gdb) print (enum E) 3
3470 * The filename part of a linespec will now match trailing components
3471 of a source file name. For example, "break gcc/expr.c:1000" will
3472 now set a breakpoint in build/gcc/expr.c, but not
3473 build/libcpp/expr.c.
3475 * The "info proc" and "generate-core-file" commands will now also
3476 work on remote targets connected to GDBserver on Linux.
3478 * The command "info catch" has been removed. It has been disabled
3479 since December 2007.
3481 * The "catch exception" and "catch assert" commands now accept
3482 a condition at the end of the command, much like the "break"
3483 command does. For instance:
3485 (gdb) catch exception Constraint_Error if Barrier = True
3487 Previously, it was possible to add a condition to such catchpoints,
3488 but it had to be done as a second step, after the catchpoint had been
3489 created, using the "condition" command.
3491 * The "info static-tracepoint-marker" command will now also work on
3492 native Linux targets with in-process agent.
3494 * GDB can now set breakpoints on inlined functions.
3496 * The .gdb_index section has been updated to include symbols for
3497 inlined functions. GDB will ignore older .gdb_index sections by
3498 default, which could cause symbol files to be loaded more slowly
3499 until their .gdb_index sections can be recreated. The new command
3500 "set use-deprecated-index-sections on" will cause GDB to use any older
3501 .gdb_index sections it finds. This will restore performance, but the
3502 ability to set breakpoints on inlined functions will be lost in symbol
3503 files with older .gdb_index sections.
3505 The .gdb_index section has also been updated to record more information
3506 about each symbol. This speeds up the "info variables", "info functions"
3507 and "info types" commands when used with programs having the .gdb_index
3508 section, as well as speeding up debugging with shared libraries using
3509 the .gdb_index section.
3511 * Ada support for GDB/MI Variable Objects has been added.
3513 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3518 ** New command -info-os is the MI equivalent of "info os".
3520 ** Output logs ("set logging" and related) now include MI output.
3524 ** "set use-deprecated-index-sections on|off"
3525 "show use-deprecated-index-sections on|off"
3526 Controls the use of deprecated .gdb_index sections.
3528 ** "catch load" and "catch unload" can be used to stop when a shared
3529 library is loaded or unloaded, respectively.
3531 ** "enable count" can be used to auto-disable a breakpoint after
3534 ** "info vtbl" can be used to show the virtual method tables for
3535 C++ and Java objects.
3537 ** "explore" and its sub commands "explore value" and "explore type"
3538 can be used to recursively explore values and types of
3539 expressions. These commands are available only if GDB is
3540 configured with '--with-python'.
3542 ** "info auto-load" shows status of all kinds of auto-loaded files,
3543 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3544 sequences of commands files, "info auto-load python-scripts"
3545 shows status of auto-loading Python script files,
3546 "info auto-load local-gdbinit" shows status of loading init file
3547 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3548 status of inferior specific thread debugging shared library loading.
3550 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3551 and "show auto-load-scripts" commands have been deprecated, use their
3552 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3553 and "show auto-load python-scripts" counterparts instead.
3555 ** "dprintf location,format,args..." creates a dynamic printf, which
3556 is basically a breakpoint that does a printf and immediately
3557 resumes your program's execution, so it is like a printf that you
3558 can insert dynamically at runtime instead of at compiletime.
3560 ** "set print symbol"
3562 Controls whether GDB attempts to display the symbol, if any,
3563 corresponding to addresses it prints. This defaults to "on", but
3564 you can set it to "off" to restore GDB's previous behavior.
3566 * Deprecated commands
3568 ** For the Renesas Super-H architecture, the "regs" command has been
3569 deprecated, and "info all-registers" should be used instead.
3573 Renesas RL78 rl78-*-elf
3574 HP OpenVMS ia64 ia64-hp-openvms*
3576 * GDBserver supports evaluation of breakpoint conditions. When
3577 support is advertised by GDBserver, GDB may be told to send the
3578 breakpoint conditions in bytecode form to GDBserver. GDBserver
3579 will only report the breakpoint trigger to GDB when its condition
3584 set mips compression
3585 show mips compression
3586 Select the compressed ISA encoding used in functions that have no symbol
3587 information available. The encoding can be set to either of:
3590 and is updated automatically from ELF file flags if available.
3592 set breakpoint condition-evaluation
3593 show breakpoint condition-evaluation
3594 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3595 GDBserver ("target"). Default option "auto" chooses the most efficient
3597 This option can improve debugger efficiency depending on the speed of the
3601 Disable auto-loading globally.
3604 Show auto-loading setting of all kinds of auto-loaded files.
3606 set auto-load gdb-scripts on|off
3607 show auto-load gdb-scripts
3608 Control auto-loading of GDB canned sequences of commands files.
3610 set auto-load python-scripts on|off
3611 show auto-load python-scripts
3612 Control auto-loading of Python script files.
3614 set auto-load local-gdbinit on|off
3615 show auto-load local-gdbinit
3616 Control loading of init file (.gdbinit) from current directory.
3618 set auto-load libthread-db on|off
3619 show auto-load libthread-db
3620 Control auto-loading of inferior specific thread debugging shared library.
3622 set auto-load scripts-directory <dir1>[:<dir2>...]
3623 show auto-load scripts-directory
3624 Set a list of directories from which to load auto-loaded scripts.
3625 Automatically loaded Python scripts and GDB scripts are located in one
3626 of the directories listed by this option.
3627 The delimiter (':' above) may differ according to the host platform.
3629 set auto-load safe-path <dir1>[:<dir2>...]
3630 show auto-load safe-path
3631 Set a list of directories from which it is safe to auto-load files.
3632 The delimiter (':' above) may differ according to the host platform.
3634 set debug auto-load on|off
3635 show debug auto-load
3636 Control display of debugging info for auto-loading the files above.
3638 set dprintf-style gdb|call|agent
3640 Control the way in which a dynamic printf is performed; "gdb"
3641 requests a GDB printf command, while "call" causes dprintf to call a
3642 function in the inferior. "agent" requests that the target agent
3643 (such as GDBserver) do the printing.
3645 set dprintf-function <expr>
3646 show dprintf-function
3647 set dprintf-channel <expr>
3648 show dprintf-channel
3649 Set the function and optional first argument to the call when using
3650 the "call" style of dynamic printf.
3652 set disconnected-dprintf on|off
3653 show disconnected-dprintf
3654 Control whether agent-style dynamic printfs continue to be in effect
3655 after GDB disconnects.
3657 * New configure options
3659 --with-auto-load-dir
3660 Configure default value for the 'set auto-load scripts-directory'
3661 setting above. It defaults to '$debugdir:$datadir/auto-load',
3662 $debugdir representing global debugging info directories (available
3663 via 'show debug-file-directory') and $datadir representing GDB's data
3664 directory (available via 'show data-directory').
3666 --with-auto-load-safe-path
3667 Configure default value for the 'set auto-load safe-path' setting
3668 above. It defaults to the --with-auto-load-dir setting.
3670 --without-auto-load-safe-path
3671 Set 'set auto-load safe-path' to '/', effectively disabling this
3674 * New remote packets
3676 z0/z1 conditional breakpoints extension
3678 The z0/z1 breakpoint insertion packets have been extended to carry
3679 a list of conditional expressions over to the remote stub depending on the
3680 condition evaluation mode. The use of this extension can be controlled
3681 via the "set remote conditional-breakpoints-packet" command.
3685 Specify the signals which the remote stub may pass to the debugged
3686 program without GDB involvement.
3688 * New command line options
3690 --init-command=FILE, -ix Like --command, -x but execute it
3691 before loading inferior.
3692 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3693 execute it before loading inferior.
3695 *** Changes in GDB 7.4
3697 * GDB now handles ambiguous linespecs more consistently; the existing
3698 FILE:LINE support has been expanded to other types of linespecs. A
3699 breakpoint will now be set on all matching locations in all
3700 inferiors, and locations will be added or removed according to
3703 * GDB now allows you to skip uninteresting functions and files when
3704 stepping with the "skip function" and "skip file" commands.
3706 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3707 and "show remote hardware-watchpoint-length-limit". These allows to
3708 set or show the maximum length limit (in bytes) of a remote
3709 target hardware watchpoint.
3711 This allows e.g. to use "unlimited" hardware watchpoints with the
3712 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3713 watchpoints are slower than real hardware watchpoints but are
3714 significantly faster than gdb software watchpoints.
3718 ** The register_pretty_printer function in module gdb.printing now takes
3719 an optional `replace' argument. If True, the new printer replaces any
3722 ** The "maint set python print-stack on|off" command has been
3723 deprecated and will be deleted in GDB 7.5.
3724 A new command: "set python print-stack none|full|message" has
3725 replaced it. Additionally, the default for "print-stack" is
3726 now "message", which just prints the error message without
3729 ** A prompt substitution hook (prompt_hook) is now available to the
3732 ** A new Python module, gdb.prompt has been added to the GDB Python
3733 modules library. This module provides functionality for
3734 escape sequences in prompts (used by set/show
3735 extended-prompt). These escape sequences are replaced by their
3736 corresponding value.
3738 ** Python commands and convenience-functions located in
3739 'data-directory'/python/gdb/command and
3740 'data-directory'/python/gdb/function are now automatically loaded
3743 ** Blocks now provide four new attributes. global_block and
3744 static_block will return the global and static blocks
3745 respectively. is_static and is_global are boolean attributes
3746 that indicate if the block is one of those two types.
3748 ** Symbols now provide the "type" attribute, the type of the symbol.
3750 ** The "gdb.breakpoint" function has been deprecated in favor of
3753 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3754 of a function. This class is based on the "finish" command
3755 available in the CLI.
3757 ** Type objects for struct and union types now allow access to
3758 the fields using standard Python dictionary (mapping) methods.
3759 For example, "some_type['myfield']" now works, as does
3760 "some_type.items()".
3762 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3765 ** A new function, "deep_items" has been added to the gdb.types
3766 module in the GDB Python modules library. This function returns
3767 an iterator over the fields of a struct or union type. Unlike
3768 the standard Python "iteritems" method, it will recursively traverse
3769 any anonymous fields.
3773 ** "*stopped" events can report several new "reason"s, such as
3776 ** Breakpoint changes are now notified using new async records, like
3777 "=breakpoint-modified".
3779 ** New command -ada-task-info.
3781 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3782 $sdir specifies the default system locations of shared libraries.
3783 $pdir specifies the directory where the libpthread used by the application
3786 GDB no longer looks in $sdir and $pdir after it has searched the directories
3787 mentioned in libthread-db-search-path. If you want to search those
3788 directories, they must be specified in libthread-db-search-path.
3789 The default value of libthread-db-search-path on GNU/Linux and Solaris
3790 systems is now "$sdir:$pdir".
3792 $pdir is not supported by gdbserver, it is currently ignored.
3793 $sdir is supported by gdbserver.
3795 * New configure option --with-iconv-bin.
3796 When using the internationalization support like the one in the GNU C
3797 library, GDB will invoke the "iconv" program to get a list of supported
3798 character sets. If this program lives in a non-standard location, one can
3799 use this option to specify where to find it.
3801 * When natively debugging programs on PowerPC BookE processors running
3802 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3803 watchpoints, which specify a mask in addition to an address to watch.
3804 The mask specifies that some bits of an address (the bits which are
3805 reset in the mask) should be ignored when matching the address accessed
3806 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3807 section in the user manual for more details.
3809 * The new option --once causes GDBserver to stop listening for connections once
3810 the first connection is made. The listening port used by GDBserver will
3811 become available after that.
3813 * New commands "info macros" and "alias" have been added.
3815 * New function parameters suffix @entry specifies value of function parameter
3816 at the time the function got called. Entry values are available only since
3822 "!" is now an alias of the "shell" command.
3823 Note that no space is needed between "!" and SHELL COMMAND.
3827 watch EXPRESSION mask MASK_VALUE
3828 The watch command now supports the mask argument which allows creation
3829 of masked watchpoints, if the current architecture supports this feature.
3831 info auto-load-scripts [REGEXP]
3832 This command was formerly named "maintenance print section-scripts".
3833 It is now generally useful and is no longer a maintenance-only command.
3835 info macro [-all] [--] MACRO
3836 The info macro command has new options `-all' and `--'. The first for
3837 printing all definitions of a macro. The second for explicitly specifying
3838 the end of arguments and the beginning of the macro name in case the macro
3839 name starts with a hyphen.
3841 collect[/s] EXPRESSIONS
3842 The tracepoint collect command now takes an optional modifier "/s"
3843 that directs it to dereference pointer-to-character types and
3844 collect the bytes of memory up to a zero byte. The behavior is
3845 similar to what you see when you use the regular print command on a
3846 string. An optional integer following the "/s" sets a bound on the
3847 number of bytes that will be collected.
3850 The trace start command now interprets any supplied arguments as a
3851 note to be recorded with the trace run, with an effect similar to
3852 setting the variable trace-notes.
3855 The trace stop command now interprets any arguments as a note to be
3856 mentioned along with the tstatus report that the trace was stopped
3857 with a command. The effect is similar to setting the variable
3860 * Tracepoints can now be enabled and disabled at any time after a trace
3861 experiment has been started using the standard "enable" and "disable"
3862 commands. It is now possible to start a trace experiment with no enabled
3863 tracepoints; GDB will display a warning, but will allow the experiment to
3864 begin, assuming that tracepoints will be enabled as needed while the trace
3867 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3868 locations with 4-byte instructions, when they were previously
3869 limited to locations with instructions of 5 bytes or longer.
3873 set debug dwarf2-read
3874 show debug dwarf2-read
3875 Turns on or off display of debugging messages related to reading
3876 DWARF debug info. The default is off.
3878 set debug symtab-create
3879 show debug symtab-create
3880 Turns on or off display of debugging messages related to symbol table
3881 creation. The default is off.
3884 show extended-prompt
3885 Set the GDB prompt, and allow escape sequences to be inserted to
3886 display miscellaneous information (see 'help set extended-prompt'
3887 for the list of sequences). This prompt (and any information
3888 accessed through the escape sequences) is updated every time the
3889 prompt is displayed.
3891 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3892 show print entry-values
3893 Set printing of frame argument values at function entry. In some cases
3894 GDB can determine the value of function argument which was passed by the
3895 function caller, even if the value was modified inside the called function.
3897 set debug entry-values
3898 show debug entry-values
3899 Control display of debugging info for determining frame argument values at
3900 function entry and virtual tail call frames.
3902 set basenames-may-differ
3903 show basenames-may-differ
3904 Set whether a source file may have multiple base names.
3905 (A "base name" is the name of a file with the directory part removed.
3906 Example: The base name of "/home/user/hello.c" is "hello.c".)
3907 If set, GDB will canonicalize file names (e.g., expand symlinks)
3908 before comparing them. Canonicalization is an expensive operation,
3909 but it allows the same file be known by more than one base name.
3910 If not set (the default), all source files are assumed to have just
3911 one base name, and gdb will do file name comparisons more efficiently.
3917 Set a user name and notes for the current and any future trace runs.
3918 This is useful for long-running and/or disconnected traces, to
3919 inform others (or yourself) as to who is running the trace, supply
3920 contact information, or otherwise explain what is going on.
3922 set trace-stop-notes
3923 show trace-stop-notes
3924 Set a note attached to the trace run, that is displayed when the
3925 trace has been stopped by a tstop command. This is useful for
3926 instance as an explanation, if you are stopping a trace run that was
3927 started by someone else.
3929 * New remote packets
3933 Dynamically enable a tracepoint in a started trace experiment.
3937 Dynamically disable a tracepoint in a started trace experiment.
3941 Set the user and notes of the trace run.
3945 Query the current status of a tracepoint.
3949 Query the minimum length of instruction at which a fast tracepoint may
3952 * Dcache size (number of lines) and line-size are now runtime-configurable
3953 via "set dcache line" and "set dcache line-size" commands.
3957 Texas Instruments TMS320C6x tic6x-*-*
3961 Renesas RL78 rl78-*-elf
3963 *** Changes in GDB 7.3.1
3965 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3967 *** Changes in GDB 7.3
3969 * GDB has a new command: "thread find [REGEXP]".
3970 It finds the thread id whose name, target id, or thread extra info
3971 matches the given regular expression.
3973 * The "catch syscall" command now works on mips*-linux* targets.
3975 * The -data-disassemble MI command now supports modes 2 and 3 for
3976 dumping the instruction opcodes.
3978 * New command line options
3980 -data-directory DIR Specify DIR as the "data-directory".
3981 This is mostly for testing purposes.
3983 * The "maint set python auto-load on|off" command has been renamed to
3984 "set auto-load-scripts on|off".
3986 * GDB has a new command: "set directories".
3987 It is like the "dir" command except that it replaces the
3988 source path list instead of augmenting it.
3990 * GDB now understands thread names.
3992 On GNU/Linux, "info threads" will display the thread name as set by
3993 prctl or pthread_setname_np.
3995 There is also a new command, "thread name", which can be used to
3996 assign a name internally for GDB to display.
3999 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4000 has been integrated into GDB.
4004 ** The function gdb.Write now accepts an optional keyword 'stream'.
4005 This keyword, when provided, will direct the output to either
4006 stdout, stderr, or GDB's logging output.
4008 ** Parameters can now be be sub-classed in Python, and in particular
4009 you may implement the get_set_doc and get_show_doc functions.
4010 This improves how Parameter set/show documentation is processed
4011 and allows for more dynamic content.
4013 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4014 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4015 have an is_valid method.
4017 ** Breakpoints can now be sub-classed in Python, and in particular
4018 you may implement a 'stop' function that is executed each time
4019 the inferior reaches that breakpoint.
4021 ** New function gdb.lookup_global_symbol looks up a global symbol.
4023 ** GDB values in Python are now callable if the value represents a
4024 function. For example, if 'some_value' represents a function that
4025 takes two integer parameters and returns a value, you can call
4026 that function like so:
4028 result = some_value (10,20)
4030 ** Module gdb.types has been added.
4031 It contains a collection of utilities for working with gdb.Types objects:
4032 get_basic_type, has_field, make_enum_dict.
4034 ** Module gdb.printing has been added.
4035 It contains utilities for writing and registering pretty-printers.
4036 New classes: PrettyPrinter, SubPrettyPrinter,
4037 RegexpCollectionPrettyPrinter.
4038 New function: register_pretty_printer.
4040 ** New commands "info pretty-printers", "enable pretty-printer" and
4041 "disable pretty-printer" have been added.
4043 ** gdb.parameter("directories") is now available.
4045 ** New function gdb.newest_frame returns the newest frame in the
4048 ** The gdb.InferiorThread class has a new "name" attribute. This
4049 holds the thread's name.
4051 ** Python Support for Inferior events.
4052 Python scripts can add observers to be notified of events
4053 occurring in the process being debugged.
4054 The following events are currently supported:
4055 - gdb.events.cont Continue event.
4056 - gdb.events.exited Inferior exited event.
4057 - gdb.events.stop Signal received, and Breakpoint hit events.
4061 ** GDB now puts template parameters in scope when debugging in an
4062 instantiation. For example, if you have:
4064 template<int X> int func (void) { return X; }
4066 then if you step into func<5>, "print X" will show "5". This
4067 feature requires proper debuginfo support from the compiler; it
4068 was added to GCC 4.5.
4070 ** The motion commands "next", "finish", "until", and "advance" now
4071 work better when exceptions are thrown. In particular, GDB will
4072 no longer lose control of the inferior; instead, the GDB will
4073 stop the inferior at the point at which the exception is caught.
4074 This functionality requires a change in the exception handling
4075 code that was introduced in GCC 4.5.
4077 * GDB now follows GCC's rules on accessing volatile objects when
4078 reading or writing target state during expression evaluation.
4079 One notable difference to prior behavior is that "print x = 0"
4080 no longer generates a read of x; the value of the assignment is
4081 now always taken directly from the value being assigned.
4083 * GDB now has some support for using labels in the program's source in
4084 linespecs. For instance, you can use "advance label" to continue
4085 execution to a label.
4087 * GDB now has support for reading and writing a new .gdb_index
4088 section. This section holds a fast index of DWARF debugging
4089 information and can be used to greatly speed up GDB startup and
4090 operation. See the documentation for `save gdb-index' for details.
4092 * The "watch" command now accepts an optional "-location" argument.
4093 When used, this causes GDB to watch the memory referred to by the
4094 expression. Such a watchpoint is never deleted due to it going out
4097 * GDB now supports thread debugging of core dumps on GNU/Linux.
4099 GDB now activates thread debugging using the libthread_db library
4100 when debugging GNU/Linux core dumps, similarly to when debugging
4101 live processes. As a result, when debugging a core dump file, GDB
4102 is now able to display pthread_t ids of threads. For example, "info
4103 threads" shows the same output as when debugging the process when it
4104 was live. In earlier releases, you'd see something like this:
4107 * 1 LWP 6780 main () at main.c:10
4109 While now you see this:
4112 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4114 It is also now possible to inspect TLS variables when debugging core
4117 When debugging a core dump generated on a machine other than the one
4118 used to run GDB, you may need to point GDB at the correct
4119 libthread_db library with the "set libthread-db-search-path"
4120 command. See the user manual for more details on this command.
4122 * When natively debugging programs on PowerPC BookE processors running
4123 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4124 which stop execution of the inferior whenever it executes an instruction
4125 at any address within the specified range. See the "PowerPC Embedded"
4126 section in the user manual for more details.
4128 * New features in the GDB remote stub, GDBserver
4130 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4131 and i686 LynxOS (version 5.x).
4133 ** GDBserver is now supported on Blackfin Linux.
4135 * New native configurations
4137 ia64 HP-UX ia64-*-hpux*
4141 Analog Devices, Inc. Blackfin Processor bfin-*
4143 * Ada task switching is now supported on sparc-elf targets when
4144 debugging a program using the Ravenscar Profile. For more information,
4145 see the "Tasking Support when using the Ravenscar Profile" section
4146 in the GDB user manual.
4148 * Guile support was removed.
4150 * New features in the GNU simulator
4152 ** The --map-info flag lists all known core mappings.
4154 ** CFI flashes may be simulated via the "cfi" device.
4156 *** Changes in GDB 7.2
4158 * Shared library support for remote targets by default
4160 When GDB is configured for a generic, non-OS specific target, like
4161 for example, --target=arm-eabi or one of the many *-*-elf targets,
4162 GDB now queries remote stubs for loaded shared libraries using the
4163 `qXfer:libraries:read' packet. Previously, shared library support
4164 was always disabled for such configurations.
4168 ** Argument Dependent Lookup (ADL)
4170 In C++ ADL lookup directs function search to the namespaces of its
4171 arguments even if the namespace has not been imported.
4181 Here the compiler will search for `foo' in the namespace of 'b'
4182 and find A::foo. GDB now supports this. This construct is commonly
4183 used in the Standard Template Library for operators.
4185 ** Improved User Defined Operator Support
4187 In addition to member operators, GDB now supports lookup of operators
4188 defined in a namespace and imported with a `using' directive, operators
4189 defined in the global scope, operators imported implicitly from an
4190 anonymous namespace, and the ADL operators mentioned in the previous
4192 GDB now also supports proper overload resolution for all the previously
4193 mentioned flavors of operators.
4195 ** static const class members
4197 Printing of static const class members that are initialized in the
4198 class definition has been fixed.
4200 * Windows Thread Information Block access.
4202 On Windows targets, GDB now supports displaying the Windows Thread
4203 Information Block (TIB) structure. This structure is visible either
4204 by using the new command `info w32 thread-information-block' or, by
4205 dereferencing the new convenience variable named `$_tlb', a
4206 thread-specific pointer to the TIB. This feature is also supported
4207 when remote debugging using GDBserver.
4209 * Static tracepoints
4211 Static tracepoints are calls in the user program into a tracing
4212 library. One such library is a port of the LTTng kernel tracer to
4213 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4214 When debugging with GDBserver, GDB now supports combining the GDB
4215 tracepoint machinery with such libraries. For example: the user can
4216 use GDB to probe a static tracepoint marker (a call from the user
4217 program into the tracing library) with the new "strace" command (see
4218 "New commands" below). This creates a "static tracepoint" in the
4219 breakpoint list, that can be manipulated with the same feature set
4220 as fast and regular tracepoints. E.g., collect registers, local and
4221 global variables, collect trace state variables, and define
4222 tracepoint conditions. In addition, the user can collect extra
4223 static tracepoint marker specific data, by collecting the new
4224 $_sdata internal variable. When analyzing the trace buffer, you can
4225 inspect $_sdata like any other variable available to GDB. For more
4226 information, see the "Tracepoints" chapter in GDB user manual. New
4227 remote packets have been defined to support static tracepoints, see
4228 the "New remote packets" section below.
4230 * Better reconstruction of tracepoints after disconnected tracing
4232 GDB will attempt to download the original source form of tracepoint
4233 definitions when starting a trace run, and then will upload these
4234 upon reconnection to the target, resulting in a more accurate
4235 reconstruction of the tracepoints that are in use on the target.
4239 You can now exercise direct control over the ways that GDB can
4240 affect your program. For instance, you can disallow the setting of
4241 breakpoints, so that the program can run continuously (assuming
4242 non-stop mode). In addition, the "observer" variable is available
4243 to switch all of the different controls; in observer mode, GDB
4244 cannot affect the target's behavior at all, which is useful for
4245 tasks like diagnosing live systems in the field.
4247 * The new convenience variable $_thread holds the number of the
4250 * New remote packets
4254 Return the address of the Windows Thread Information Block of a given thread.
4258 In response to several of the tracepoint packets, the target may now
4259 also respond with a number of intermediate `qRelocInsn' request
4260 packets before the final result packet, to have GDB handle
4261 relocating an instruction to execute at a different address. This
4262 is particularly useful for stubs that support fast tracepoints. GDB
4263 reports support for this feature in the qSupported packet.
4267 List static tracepoint markers in the target program.
4271 List static tracepoint markers at a given address in the target
4274 qXfer:statictrace:read
4276 Read the static trace data collected (by a `collect $_sdata'
4277 tracepoint action). The remote stub reports support for this packet
4278 to gdb's qSupported query.
4282 Send the current settings of GDB's permission flags.
4286 Send part of the source (textual) form of a tracepoint definition,
4287 which includes location, conditional, and action list.
4289 * The source command now accepts a -s option to force searching for the
4290 script in the source search path even if the script name specifies
4293 * New features in the GDB remote stub, GDBserver
4295 - GDBserver now support tracepoints (including fast tracepoints, and
4296 static tracepoints). The feature is currently supported by the
4297 i386-linux and amd64-linux builds. See the "Tracepoints support
4298 in gdbserver" section in the manual for more information.
4300 GDBserver JIT compiles the tracepoint's conditional agent
4301 expression bytecode into native code whenever possible for low
4302 overhead dynamic tracepoints conditionals. For such tracepoints,
4303 an expression that examines program state is evaluated when the
4304 tracepoint is reached, in order to determine whether to capture
4305 trace data. If the condition is simple and false, processing the
4306 tracepoint finishes very quickly and no data is gathered.
4308 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4309 for static tracepoints support.
4311 - GDBserver now supports x86_64 Windows 64-bit debugging.
4313 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4314 it understands register description.
4316 * The --batch flag now disables pagination and queries.
4318 * X86 general purpose registers
4320 GDB now supports reading/writing byte, word and double-word x86
4321 general purpose registers directly. This means you can use, say,
4322 $ah or $ax to refer, respectively, to the byte register AH and
4323 16-bit word register AX that are actually portions of the 32-bit
4324 register EAX or 64-bit register RAX.
4326 * The `commands' command now accepts a range of breakpoints to modify.
4327 A plain `commands' following a command that creates multiple
4328 breakpoints affects all the breakpoints set by that command. This
4329 applies to breakpoints set by `rbreak', and also applies when a
4330 single `break' command creates multiple breakpoints (e.g.,
4331 breakpoints on overloaded c++ functions).
4333 * The `rbreak' command now accepts a filename specification as part of
4334 its argument, limiting the functions selected by the regex to those
4335 in the specified file.
4337 * Support for remote debugging Windows and SymbianOS shared libraries
4338 from Unix hosts has been improved. Non Windows GDB builds now can
4339 understand target reported file names that follow MS-DOS based file
4340 system semantics, such as file names that include drive letters and
4341 use the backslash character as directory separator. This makes it
4342 possible to transparently use the "set sysroot" and "set
4343 solib-search-path" on Unix hosts to point as host copies of the
4344 target's shared libraries. See the new command "set
4345 target-file-system-kind" described below, and the "Commands to
4346 specify files" section in the user manual for more information.
4350 eval template, expressions...
4351 Convert the values of one or more expressions under the control
4352 of the string template to a command line, and call it.
4354 set target-file-system-kind unix|dos-based|auto
4355 show target-file-system-kind
4356 Set or show the assumed file system kind for target reported file
4359 save breakpoints <filename>
4360 Save all current breakpoint definitions to a file suitable for use
4361 in a later debugging session. To read the saved breakpoint
4362 definitions, use the `source' command.
4364 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4367 info static-tracepoint-markers
4368 Display information about static tracepoint markers in the target.
4370 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4371 Define a static tracepoint by probing a marker at the given
4372 function, line, address, or marker ID.
4376 Enable and disable observer mode.
4378 set may-write-registers on|off
4379 set may-write-memory on|off
4380 set may-insert-breakpoints on|off
4381 set may-insert-tracepoints on|off
4382 set may-insert-fast-tracepoints on|off
4383 set may-interrupt on|off
4384 Set individual permissions for GDB effects on the target. Note that
4385 some of these settings can have undesirable or surprising
4386 consequences, particularly when changed in the middle of a session.
4387 For instance, disabling the writing of memory can prevent
4388 breakpoints from being inserted, cause single-stepping to fail, or
4389 even crash your program, if you disable after breakpoints have been
4390 inserted. However, GDB should not crash.
4392 set record memory-query on|off
4393 show record memory-query
4394 Control whether to stop the inferior if memory changes caused
4395 by an instruction cannot be recorded.
4400 The disassemble command now supports "start,+length" form of two arguments.
4404 ** GDB now provides a new directory location, called the python directory,
4405 where Python scripts written for GDB can be installed. The location
4406 of that directory is <data-directory>/python, where <data-directory>
4407 is the GDB data directory. For more details, see section `Scripting
4408 GDB using Python' in the manual.
4410 ** The GDB Python API now has access to breakpoints, symbols, symbol
4411 tables, program spaces, inferiors, threads and frame's code blocks.
4412 Additionally, GDB Parameters can now be created from the API, and
4413 manipulated via set/show in the CLI.
4415 ** New functions gdb.target_charset, gdb.target_wide_charset,
4416 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4418 ** New exception gdb.GdbError.
4420 ** Pretty-printers are now also looked up in the current program space.
4422 ** Pretty-printers can now be individually enabled and disabled.
4424 ** GDB now looks for names of Python scripts to auto-load in a
4425 special section named `.debug_gdb_scripts', in addition to looking
4426 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4428 * Tracepoint actions were unified with breakpoint commands. In particular,
4429 there are no longer differences in "info break" output for breakpoints and
4430 tracepoints and the "commands" command can be used for both tracepoints and
4431 regular breakpoints.
4435 ARM Symbian arm*-*-symbianelf*
4437 * D language support.
4438 GDB now supports debugging programs written in the D programming
4441 * GDB now supports the extended ptrace interface for PowerPC which is
4442 available since Linux kernel version 2.6.34. This automatically enables
4443 any hardware breakpoints and additional hardware watchpoints available in
4444 the processor. The old ptrace interface exposes just one hardware
4445 watchpoint and no hardware breakpoints.
4447 * GDB is now able to use the Data Value Compare (DVC) register available on
4448 embedded PowerPC processors to implement in hardware simple watchpoint
4449 conditions of the form:
4451 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4453 This works in native GDB running on Linux kernels with the extended ptrace
4454 interface mentioned above.
4456 *** Changes in GDB 7.1
4460 ** Namespace Support
4462 GDB now supports importing of namespaces in C++. This enables the
4463 user to inspect variables from imported namespaces. Support for
4464 namepace aliasing has also been added. So, if a namespace is
4465 aliased in the current scope (e.g. namepace C=A; ) the user can
4466 print variables using the alias (e.g. (gdb) print C::x).
4470 All known bugs relating to the printing of virtual base class were
4471 fixed. It is now possible to call overloaded static methods using a
4476 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4477 and reinterpret_cast<> are now handled by the C++ expression parser.
4481 Xilinx MicroBlaze microblaze-*-*
4486 Xilinx MicroBlaze microblaze
4489 * Multi-program debugging.
4491 GDB now has support for multi-program (a.k.a. multi-executable or
4492 multi-exec) debugging. This allows for debugging multiple inferiors
4493 simultaneously each running a different program under the same GDB
4494 session. See "Debugging Multiple Inferiors and Programs" in the
4495 manual for more information. This implied some user visible changes
4496 in the multi-inferior support. For example, "info inferiors" now
4497 lists inferiors that are not running yet or that have exited
4498 already. See also "New commands" and "New options" below.
4500 * New tracing features
4502 GDB's tracepoint facility now includes several new features:
4504 ** Trace state variables
4506 GDB tracepoints now include support for trace state variables, which
4507 are variables managed by the target agent during a tracing
4508 experiment. They are useful for tracepoints that trigger each
4509 other, so for instance one tracepoint can count hits in a variable,
4510 and then a second tracepoint has a condition that is true when the
4511 count reaches a particular value. Trace state variables share the
4512 $-syntax of GDB convenience variables, and can appear in both
4513 tracepoint actions and condition expressions. Use the "tvariable"
4514 command to create, and "info tvariables" to view; see "Trace State
4515 Variables" in the manual for more detail.
4519 GDB now includes an option for defining fast tracepoints, which
4520 targets may implement more efficiently, such as by installing a jump
4521 into the target agent rather than a trap instruction. The resulting
4522 speedup can be by two orders of magnitude or more, although the
4523 tradeoff is that some program locations on some target architectures
4524 might not allow fast tracepoint installation, for instance if the
4525 instruction to be replaced is shorter than the jump. To request a
4526 fast tracepoint, use the "ftrace" command, with syntax identical to
4527 the regular trace command.
4529 ** Disconnected tracing
4531 It is now possible to detach GDB from the target while it is running
4532 a trace experiment, then reconnect later to see how the experiment
4533 is going. In addition, a new variable disconnected-tracing lets you
4534 tell the target agent whether to continue running a trace if the
4535 connection is lost unexpectedly.
4539 GDB now has the ability to save the trace buffer into a file, and
4540 then use that file as a target, similarly to you can do with
4541 corefiles. You can select trace frames, print data that was
4542 collected in them, and use tstatus to display the state of the
4543 tracing run at the moment that it was saved. To create a trace
4544 file, use "tsave <filename>", and to use it, do "target tfile
4547 ** Circular trace buffer
4549 You can ask the target agent to handle the trace buffer as a
4550 circular buffer, discarding the oldest trace frames to make room for
4551 newer ones, by setting circular-trace-buffer to on. This feature may
4552 not be available for all target agents.
4557 The disassemble command, when invoked with two arguments, now requires
4558 the arguments to be comma-separated.
4561 The info variables command now displays variable definitions. Files
4562 which only declare a variable are not shown.
4565 The source command is now capable of sourcing Python scripts.
4566 This feature is dependent on the debugger being build with Python
4569 Related to this enhancement is also the introduction of a new command
4570 "set script-extension" (see below).
4572 * New commands (for set/show, see "New options" below)
4574 record save [<FILENAME>]
4575 Save a file (in core file format) containing the process record
4576 execution log for replay debugging at a later time.
4578 record restore <FILENAME>
4579 Restore the process record execution log that was saved at an
4580 earlier time, for replay debugging.
4582 add-inferior [-copies <N>] [-exec <FILENAME>]
4585 clone-inferior [-copies <N>] [ID]
4586 Make a new inferior ready to execute the same program another
4587 inferior has loaded.
4592 maint info program-spaces
4593 List the program spaces loaded into GDB.
4595 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4596 show remote interrupt-sequence
4597 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4598 as the sequence to the remote target in order to interrupt the execution.
4599 Ctrl-C is a default. Some system prefers BREAK which is high level of
4600 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4601 Magic SysRq g. It is BREAK signal and character 'g'.
4603 set remote interrupt-on-connect [on | off]
4604 show remote interrupt-on-connect
4605 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4606 remote target when gdb connects to it. This is needed when you debug
4609 set remotebreak [on | off]
4611 Deprecated. Use "set/show remote interrupt-sequence" instead.
4613 tvariable $NAME [ = EXP ]
4614 Create or modify a trace state variable.
4617 List trace state variables and their values.
4619 delete tvariable $NAME ...
4620 Delete one or more trace state variables.
4623 Evaluate the given expressions without collecting anything into the
4624 trace buffer. (Valid in tracepoint actions only.)
4626 ftrace FN / FILE:LINE / *ADDR
4627 Define a fast tracepoint at the given function, line, or address.
4629 * New expression syntax
4631 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4632 GDB now parses 0b101010 identically with 42.
4636 set follow-exec-mode new|same
4637 show follow-exec-mode
4638 Control whether GDB reuses the same inferior across an exec call or
4639 creates a new one. This is useful to be able to restart the old
4640 executable after the inferior having done an exec call.
4642 set default-collect EXPR, ...
4643 show default-collect
4644 Define a list of expressions to be collected at each tracepoint.
4645 This is a useful way to ensure essential items are not overlooked,
4646 such as registers or a critical global variable.
4648 set disconnected-tracing
4649 show disconnected-tracing
4650 If set to 1, the target is instructed to continue tracing if it
4651 loses its connection to GDB. If 0, the target is to stop tracing
4654 set circular-trace-buffer
4655 show circular-trace-buffer
4656 If set to on, the target is instructed to use a circular trace buffer
4657 and discard the oldest trace frames instead of stopping the trace due
4658 to a full trace buffer. If set to off, the trace stops when the buffer
4659 fills up. Some targets may not support this.
4661 set script-extension off|soft|strict
4662 show script-extension
4663 If set to "off", the debugger does not perform any script language
4664 recognition, and all sourced files are assumed to be GDB scripts.
4665 If set to "soft" (the default), files are sourced according to
4666 filename extension, falling back to GDB scripts if the first
4668 If set to "strict", files are sourced according to filename extension.
4670 set ada trust-PAD-over-XVS on|off
4671 show ada trust-PAD-over-XVS
4672 If off, activate a workaround against a bug in the debugging information
4673 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4674 the GCC sources for more information about the GNAT encoding and
4675 PAD types in particular). It is always safe to set this option to
4676 off, but this introduces a slight performance penalty. The default
4679 * Python API Improvements
4681 ** GDB provides the new class gdb.LazyString. This is useful in
4682 some pretty-printing cases. The new method gdb.Value.lazy_string
4683 provides a simple way to create objects of this type.
4685 ** The fields returned by gdb.Type.fields now have an
4686 `is_base_class' attribute.
4688 ** The new method gdb.Type.range returns the range of an array type.
4690 ** The new method gdb.parse_and_eval can be used to parse and
4691 evaluate an expression.
4693 * New remote packets
4696 Define a trace state variable.
4699 Get the current value of a trace state variable.
4702 Set desired tracing behavior upon disconnection.
4705 Set the trace buffer to be linear or circular.
4708 Get data about the tracepoints currently in use.
4712 Process record now works correctly with hardware watchpoints.
4714 Multiple bug fixes have been made to the mips-irix port, making it
4715 much more reliable. In particular:
4716 - Debugging threaded applications is now possible again. Previously,
4717 GDB would hang while starting the program, or while waiting for
4718 the program to stop at a breakpoint.
4719 - Attaching to a running process no longer hangs.
4720 - An error occurring while loading a core file has been fixed.
4721 - Changing the value of the PC register now works again. This fixes
4722 problems observed when using the "jump" command, or when calling
4723 a function from GDB, or even when assigning a new value to $pc.
4724 - With the "finish" and "return" commands, the return value for functions
4725 returning a small array is now correctly printed.
4726 - It is now possible to break on shared library code which gets executed
4727 during a shared library init phase (code executed while executing
4728 their .init section). Previously, the breakpoint would have no effect.
4729 - GDB is now able to backtrace through the signal handler for
4730 non-threaded programs.
4732 PIE (Position Independent Executable) programs debugging is now supported.
4733 This includes debugging execution of PIC (Position Independent Code) shared
4734 libraries although for that, it should be possible to run such libraries as an
4737 *** Changes in GDB 7.0
4739 * GDB now has an interface for JIT compilation. Applications that
4740 dynamically generate code can create symbol files in memory and register
4741 them with GDB. For users, the feature should work transparently, and
4742 for JIT developers, the interface is documented in the GDB manual in the
4743 "JIT Compilation Interface" chapter.
4745 * Tracepoints may now be conditional. The syntax is as for
4746 breakpoints; either an "if" clause appended to the "trace" command,
4747 or the "condition" command is available. GDB sends the condition to
4748 the target for evaluation using the same bytecode format as is used
4749 for tracepoint actions.
4751 * The disassemble command now supports: an optional /r modifier, print the
4752 raw instructions in hex as well as in symbolic form, and an optional /m
4753 modifier to print mixed source+assembly.
4755 * Process record and replay
4757 In a architecture environment that supports ``process record and
4758 replay'', ``process record and replay'' target can record a log of
4759 the process execution, and replay it with both forward and reverse
4762 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4763 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4764 set execution-direction {forward|reverse}, for targets that support
4767 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4768 feature is available with a native GDB running on kernel version
4771 * GDB now has support for multi-byte and wide character sets on the
4772 target. Strings whose character type is wchar_t, char16_t, or
4773 char32_t are now correctly printed. GDB supports wide- and unicode-
4774 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4775 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4776 `printf'. This feature requires iconv to work properly; if your
4777 system does not have a working iconv, GDB can use GNU libiconv. See
4778 the installation instructions for more information.
4780 * GDB now supports automatic retrieval of shared library files from
4781 remote targets. To use this feature, specify a system root that begins
4782 with the `remote:' prefix, either via the `set sysroot' command or via
4783 the `--with-sysroot' configure-time option.
4785 * "info sharedlibrary" now takes an optional regex of libraries to show,
4786 and it now reports if a shared library has no debugging information.
4788 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4789 now complete on file names.
4791 * When completing in expressions, gdb will attempt to limit
4792 completions to allowable structure or union fields, where appropriate.
4793 For instance, consider:
4795 # struct example { int f1; double f2; };
4796 # struct example variable;
4799 If the user types TAB at the end of this command line, the available
4800 completions will be "f1" and "f2".
4802 * Inlined functions are now supported. They show up in backtraces, and
4803 the "step", "next", and "finish" commands handle them automatically.
4805 * GDB now supports the token-splicing (##) and stringification (#)
4806 operators when expanding macros. It also supports variable-arity
4809 * GDB now supports inspecting extra signal information, exported by
4810 the new $_siginfo convenience variable. The feature is currently
4811 implemented on linux ARM, i386 and amd64.
4813 * GDB can now display the VFP floating point registers and NEON vector
4814 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4815 can provide these registers (requires Linux 2.6.30 or later). Remote
4816 and simulator targets may also provide them.
4818 * New remote packets
4821 Search memory for a sequence of bytes.
4824 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4825 operation over reliable transport links. Use of this packet is
4826 controlled by the `set remote noack-packet' command.
4829 Kill the process with the specified process ID. Use this in preference
4830 to `k' when multiprocess protocol extensions are supported.
4833 Obtains additional operating system information
4837 Read or write additional signal information.
4839 * Removed remote protocol undocumented extension
4841 An undocumented extension to the remote protocol's `S' stop reply
4842 packet that permitted the stub to pass a process id was removed.
4843 Remote servers should use the `T' stop reply packet instead.
4845 * GDB now supports multiple function calling conventions according to the
4846 DWARF-2 DW_AT_calling_convention function attribute.
4848 * The SH target utilizes the aforementioned change to distinguish between gcc
4849 and Renesas calling convention. It also adds the new CLI commands
4850 `set/show sh calling-convention'.
4852 * GDB can now read compressed debug sections, as produced by GNU gold
4853 with the --compress-debug-sections=zlib flag.
4855 * 64-bit core files are now supported on AIX.
4857 * Thread switching is now supported on Tru64.
4859 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4860 which will be allocated using malloc later in program execution.
4862 * The qXfer:libraries:read remote protocol packet now allows passing a
4863 list of section offsets.
4865 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4866 conditions handling signals delivered during attach or thread creation
4867 have also been fixed.
4869 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4870 From the user's standpoint, all unqualified instances of True and False
4871 are treated as the standard definitions, regardless of context.
4873 * GDB now parses C++ symbol and type names more flexibly. For
4876 template<typename T> class C { };
4879 GDB will now correctly handle all of:
4881 ptype C<char const *>
4882 ptype C<char const*>
4883 ptype C<const char *>
4884 ptype C<const char*>
4886 * New features in the GDB remote stub, gdbserver
4888 - The "--wrapper" command-line argument tells gdbserver to use a
4889 wrapper program to launch programs for debugging.
4891 - On PowerPC and S/390 targets, it is now possible to use a single
4892 gdbserver executable to debug both 32-bit and 64-bit programs.
4893 (This requires gdbserver itself to be built as a 64-bit executable.)
4895 - gdbserver uses the new noack protocol mode for TCP connections to
4896 reduce communications latency, if also supported and enabled in GDB.
4898 - Support for the sparc64-linux-gnu target is now included in
4901 - The amd64-linux build of gdbserver now supports debugging both
4902 32-bit and 64-bit programs.
4904 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4905 now support hardware watchpoints, and will use them automatically
4910 GDB now has support for scripting using Python. Whether this is
4911 available is determined at configure time.
4913 New GDB commands can now be written in Python.
4915 * Ada tasking support
4917 Ada tasks can now be inspected in GDB. The following commands have
4921 Print the list of Ada tasks.
4923 Print detailed information about task number N.
4925 Print the task number of the current task.
4927 Switch the context of debugging to task number N.
4929 * Support for user-defined prefixed commands. The "define" command can
4930 add new commands to existing prefixes, e.g. "target".
4932 * Multi-inferior, multi-process debugging.
4934 GDB now has generalized support for multi-inferior debugging. See
4935 "Debugging Multiple Inferiors" in the manual for more information.
4936 Although availability still depends on target support, the command
4937 set is more uniform now. The GNU/Linux specific multi-forks support
4938 has been migrated to this new framework. This implied some user
4939 visible changes; see "New commands" and also "Removed commands"
4942 * Target descriptions can now describe the target OS ABI. See the
4943 "Target Description Format" section in the user manual for more
4946 * Target descriptions can now describe "compatible" architectures
4947 to indicate that the target can execute applications for a different
4948 architecture in addition to those for the main target architecture.
4949 See the "Target Description Format" section in the user manual for
4952 * Multi-architecture debugging.
4954 GDB now includes general supports for debugging applications on
4955 hybrid systems that use more than one single processor architecture
4956 at the same time. Each such hybrid architecture still requires
4957 specific support to be added. The only hybrid architecture supported
4958 in this version of GDB is the Cell Broadband Engine.
4960 * GDB now supports integrated debugging of Cell/B.E. applications that
4961 use both the PPU and SPU architectures. To enable support for hybrid
4962 Cell/B.E. debugging, you need to configure GDB to support both the
4963 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4964 --enable-targets configure option.
4966 * Non-stop mode debugging.
4968 For some targets, GDB now supports an optional mode of operation in
4969 which you can examine stopped threads while other threads continue
4970 to execute freely. This is referred to as non-stop mode, with the
4971 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4972 section in the user manual for more information.
4974 To be able to support remote non-stop debugging, a remote stub needs
4975 to implement the non-stop mode remote protocol extensions, as
4976 described in the "Remote Non-Stop" section of the user manual. The
4977 GDB remote stub, gdbserver, has been adjusted to support these
4978 extensions on linux targets.
4980 * New commands (for set/show, see "New options" below)
4982 catch syscall [NAME(S) | NUMBER(S)]
4983 Catch system calls. Arguments, which should be names of system
4984 calls or their numbers, mean catch only those syscalls. Without
4985 arguments, every syscall will be caught. When the inferior issues
4986 any of the specified syscalls, GDB will stop and announce the system
4987 call, both when it is called and when its call returns. This
4988 feature is currently available with a native GDB running on the
4989 Linux Kernel, under the following architectures: x86, x86_64,
4990 PowerPC and PowerPC64.
4992 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4994 Search memory for a sequence of bytes.
4996 maint set python print-stack
4997 maint show python print-stack
4998 Show a stack trace when an error is encountered in a Python script.
5001 Invoke CODE by passing it to the Python interpreter.
5006 These allow macros to be defined, undefined, and listed
5010 Show operating system information about processes.
5013 List the inferiors currently under GDB's control.
5016 Switch focus to inferior number NUM.
5019 Detach from inferior number NUM.
5022 Kill inferior number NUM.
5026 set spu stop-on-load
5027 show spu stop-on-load
5028 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5030 set spu auto-flush-cache
5031 show spu auto-flush-cache
5032 Control whether to automatically flush the software-managed cache
5033 during Cell/B.E. debugging.
5035 set sh calling-convention
5036 show sh calling-convention
5037 Control the calling convention used when calling SH target functions.
5040 show debug timestamp
5041 Control display of timestamps with GDB debugging output.
5043 set disassemble-next-line
5044 show disassemble-next-line
5045 Control display of disassembled source lines or instructions when
5048 set remote noack-packet
5049 show remote noack-packet
5050 Set/show the use of remote protocol QStartNoAckMode packet. See above
5051 under "New remote packets."
5053 set remote query-attached-packet
5054 show remote query-attached-packet
5055 Control use of remote protocol `qAttached' (query-attached) packet.
5057 set remote read-siginfo-object
5058 show remote read-siginfo-object
5059 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5062 set remote write-siginfo-object
5063 show remote write-siginfo-object
5064 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5067 set remote reverse-continue
5068 show remote reverse-continue
5069 Control use of remote protocol 'bc' (reverse-continue) packet.
5071 set remote reverse-step
5072 show remote reverse-step
5073 Control use of remote protocol 'bs' (reverse-step) packet.
5075 set displaced-stepping
5076 show displaced-stepping
5077 Control displaced stepping mode. Displaced stepping is a way to
5078 single-step over breakpoints without removing them from the debuggee.
5079 Also known as "out-of-line single-stepping".
5082 show debug displaced
5083 Control display of debugging info for displaced stepping.
5085 maint set internal-error
5086 maint show internal-error
5087 Control what GDB does when an internal error is detected.
5089 maint set internal-warning
5090 maint show internal-warning
5091 Control what GDB does when an internal warning is detected.
5096 Use a wrapper program to launch programs for debugging.
5098 set multiple-symbols (all|ask|cancel)
5099 show multiple-symbols
5100 The value of this variable can be changed to adjust the debugger behavior
5101 when an expression or a breakpoint location contains an ambiguous symbol
5102 name (an overloaded function name, for instance).
5104 set breakpoint always-inserted
5105 show breakpoint always-inserted
5106 Keep breakpoints always inserted in the target, as opposed to inserting
5107 them when resuming the target, and removing them when the target stops.
5108 This option can improve debugger performance on slow remote targets.
5110 set arm fallback-mode (arm|thumb|auto)
5111 show arm fallback-mode
5112 set arm force-mode (arm|thumb|auto)
5114 These commands control how ARM GDB determines whether instructions
5115 are ARM or Thumb. The default for both settings is auto, which uses
5116 the current CPSR value for instructions without symbols; previous
5117 versions of GDB behaved as if "set arm fallback-mode arm".
5119 set disable-randomization
5120 show disable-randomization
5121 Standalone programs run with the virtual address space randomization enabled
5122 by default on some platforms. This option keeps the addresses stable across
5123 multiple debugging sessions.
5127 Control whether other threads are stopped or not when some thread hits
5132 Requests that asynchronous execution is enabled in the target, if available.
5133 In this case, it's possible to resume target in the background, and interact
5134 with GDB while the target is running. "show target-async" displays the
5135 current state of asynchronous execution of the target.
5137 set target-wide-charset
5138 show target-wide-charset
5139 The target-wide-charset is the name of the character set that GDB
5140 uses when printing characters whose type is wchar_t.
5142 set tcp auto-retry (on|off)
5144 set tcp connect-timeout
5145 show tcp connect-timeout
5146 These commands allow GDB to retry failed TCP connections to a remote stub
5147 with a specified timeout period; this is useful if the stub is launched
5148 in parallel with GDB but may not be ready to accept connections immediately.
5150 set libthread-db-search-path
5151 show libthread-db-search-path
5152 Control list of directories which GDB will search for appropriate
5155 set schedule-multiple (on|off)
5156 show schedule-multiple
5157 Allow GDB to resume all threads of all processes or only threads of
5158 the current process.
5162 Use more aggressive caching for accesses to the stack. This improves
5163 performance of remote debugging (particularly backtraces) without
5164 affecting correctness.
5166 set interactive-mode (on|off|auto)
5167 show interactive-mode
5168 Control whether GDB runs in interactive mode (on) or not (off).
5169 When in interactive mode, GDB waits for the user to answer all
5170 queries. Otherwise, GDB does not wait and assumes the default
5171 answer. When set to auto (the default), GDB determines which
5172 mode to use based on the stdin settings.
5177 For program forks, this is replaced by the new more generic `info
5178 inferiors' command. To list checkpoints, you can still use the
5179 `info checkpoints' command, which was an alias for the `info forks'
5183 Replaced by the new `inferior' command. To switch between
5184 checkpoints, you can still use the `restart' command, which was an
5185 alias for the `fork' command.
5188 This is removed, since some targets don't have a notion of
5189 processes. To switch between processes, you can still use the
5190 `inferior' command using GDB's own inferior number.
5193 For program forks, this is replaced by the new more generic `kill
5194 inferior' command. To delete a checkpoint, you can still use the
5195 `delete checkpoint' command, which was an alias for the `delete
5199 For program forks, this is replaced by the new more generic `detach
5200 inferior' command. To detach a checkpoint, you can still use the
5201 `detach checkpoint' command, which was an alias for the `detach
5204 * New native configurations
5206 x86/x86_64 Darwin i[34567]86-*-darwin*
5208 x86_64 MinGW x86_64-*-mingw*
5212 Lattice Mico32 lm32-*
5213 x86 DICOS i[34567]86-*-dicos*
5214 x86_64 DICOS x86_64-*-dicos*
5217 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5218 (mingw32ce) debugging.
5224 These commands were actually not implemented on any target.
5226 *** Changes in GDB 6.8
5228 * New native configurations
5230 NetBSD/hppa hppa*-*netbsd*
5231 Xtensa GNU/Linux xtensa*-*-linux*
5235 NetBSD/hppa hppa*-*-netbsd*
5236 Xtensa GNU/Linux xtensa*-*-linux*
5238 * Change in command line behavior -- corefiles vs. process ids.
5240 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5241 attaching to process NUMBER fails, GDB no longer attempts to open a
5242 core file named NUMBER. Attaching to a program using the -c option
5243 is no longer supported. Instead, use the '-p' or '--pid' options.
5245 * GDB can now be built as a native debugger for debugging Windows x86
5246 (mingw32) Portable Executable (PE) programs.
5248 * Pending breakpoints no longer change their number when their address
5251 * GDB now supports breakpoints with multiple locations,
5252 including breakpoints on C++ constructors, inside C++ templates,
5253 and in inlined functions.
5255 * GDB's ability to debug optimized code has been improved. GDB more
5256 accurately identifies function bodies and lexical blocks that occupy
5257 more than one contiguous range of addresses.
5259 * Target descriptions can now describe registers for PowerPC.
5261 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5262 registers on PowerPC targets.
5264 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5265 targets even when the libthread_db library is not available.
5267 * The GDB remote stub, gdbserver, now supports the new file transfer
5268 commands (remote put, remote get, and remote delete).
5270 * The GDB remote stub, gdbserver, now supports run and attach in
5271 extended-remote mode.
5273 * hppa*64*-*-hpux11* target broken
5274 The debugger is unable to start a program and fails with the following
5275 error: "Error trying to get information about dynamic linker".
5276 The gdb-6.7 release is also affected.
5278 * GDB now supports the --enable-targets= configure option to allow
5279 building a single GDB executable that supports multiple remote
5280 target architectures.
5282 * GDB now supports debugging C and C++ programs which use the
5283 Decimal Floating Point extension. In addition, the PowerPC target
5284 now has a set of pseudo-registers to inspect decimal float values
5285 stored in two consecutive float registers.
5287 * The -break-insert MI command can optionally create pending
5290 * Improved support for debugging Ada
5291 Many improvements to the Ada language support have been made. These
5293 - Better support for Ada2005 interface types
5294 - Improved handling of arrays and slices in general
5295 - Better support for Taft-amendment types
5296 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5298 - Improved command completion in Ada
5301 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5306 set print frame-arguments (all|scalars|none)
5307 show print frame-arguments
5308 The value of this variable can be changed to control which argument
5309 values should be printed by the debugger when displaying a frame.
5314 Transfer files to and from a remote target, and delete remote files.
5321 Transfer files to and from a remote target, and delete remote files.
5323 * New remote packets
5330 Open, close, read, write, and delete files on the remote system.
5333 Attach to an existing process on the remote system, in extended-remote
5337 Run a new process on the remote system, in extended-remote mode.
5339 *** Changes in GDB 6.7
5341 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5342 bfd, libiberty and opcodes, as revealed by static analysis donated by
5343 Coverity, Inc. (http://scan.coverity.com).
5345 * When looking up multiply-defined global symbols, GDB will now prefer the
5346 symbol definition in the current shared library if it was built using the
5347 -Bsymbolic linker option.
5349 * When the Text User Interface (TUI) is not configured, GDB will now
5350 recognize the -tui command-line option and print a message that the TUI
5353 * The GDB remote stub, gdbserver, now has lower overhead for high
5354 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5356 * GDB for MIPS targets now autodetects whether a remote target provides
5357 32-bit or 64-bit register values.
5359 * Support for C++ member pointers has been improved.
5361 * GDB now understands XML target descriptions, which specify the
5362 target's overall architecture. GDB can read a description from
5363 a local file or over the remote serial protocol.
5365 * Vectors of single-byte data use a new integer type which is not
5366 automatically displayed as character or string data.
5368 * The /s format now works with the print command. It displays
5369 arrays of single-byte integers and pointers to single-byte integers
5372 * Target descriptions can now describe target-specific registers,
5373 for architectures which have implemented the support (currently
5374 only ARM, M68K, and MIPS).
5376 * GDB and the GDB remote stub, gdbserver, now support the XScale
5379 * The GDB remote stub, gdbserver, has been updated to support
5380 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5381 has been rewritten to use the standard GDB remote protocol.
5383 * GDB can now step into C++ functions which are called through thunks.
5385 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5387 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5388 layout. It also supports a TextSeg= and DataSeg= response when only
5389 segment base addresses (rather than offsets) are available.
5391 * The /i format now outputs any trailing branch delay slot instructions
5392 immediately following the last instruction within the count specified.
5394 * The GDB remote protocol "T" stop reply packet now supports a
5395 "library" response. Combined with the new "qXfer:libraries:read"
5396 packet, this response allows GDB to debug shared libraries on targets
5397 where the operating system manages the list of loaded libraries (e.g.
5398 Windows and SymbianOS).
5400 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5401 (DLLs) on Windows and Windows CE targets.
5403 * GDB now supports a faster verification that a .debug file matches its binary
5404 according to its build-id signature, if the signature is present.
5410 Enable or disable hardware flow control (RTS/CTS) on the serial port
5411 when debugging using remote targets.
5413 set mem inaccessible-by-default
5414 show mem inaccessible-by-default
5415 If the target supplies a memory map, for instance via the remote
5416 protocol's "qXfer:memory-map:read" packet, setting this variable
5417 prevents GDB from accessing memory outside the memory map. This
5418 is useful for targets with memory mapped registers or which react
5419 badly to accesses of unmapped address space.
5421 set breakpoint auto-hw
5422 show breakpoint auto-hw
5423 If the target supplies a memory map, for instance via the remote
5424 protocol's "qXfer:memory-map:read" packet, setting this variable
5425 lets GDB use hardware breakpoints automatically for memory regions
5426 where it can not use software breakpoints. This covers both the
5427 "break" command and internal breakpoints used for other commands
5428 including "next" and "finish".
5431 catch exception unhandled
5432 Stop the program execution when Ada exceptions are raised.
5435 Stop the program execution when an Ada assertion failed.
5439 Set an alternate system root for target files. This is a more
5440 general version of "set solib-absolute-prefix", which is now
5441 an alias to "set sysroot".
5444 Provide extended SPU facility status information. This set of
5445 commands is available only when debugging the Cell/B.E. SPU
5448 * New native configurations
5450 OpenBSD/sh sh*-*openbsd*
5453 unset tdesc filename
5455 Use the specified local file as an XML target description, and do
5456 not query the target for its built-in description.
5460 OpenBSD/sh sh*-*-openbsd*
5461 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5462 Toshiba Media Processor mep-elf
5464 * New remote packets
5467 Ignore the specified signals; pass them directly to the debugged program
5468 without stopping other threads or reporting them to GDB.
5470 qXfer:features:read:
5471 Read an XML target description from the target, which describes its
5476 Read or write contents of an spufs file on the target system. These
5477 packets are available only on the Cell/B.E. SPU architecture.
5479 qXfer:libraries:read:
5480 Report the loaded shared libraries. Combined with new "T" packet
5481 response, this packet allows GDB to debug shared libraries on
5482 targets where the operating system manages the list of loaded
5483 libraries (e.g. Windows and SymbianOS).
5487 Support for these obsolete configurations has been removed.
5495 i[34567]86-*-lynxos*
5496 i[34567]86-*-netware*
5497 i[34567]86-*-sco3.2v5*
5498 i[34567]86-*-sco3.2v4*
5500 i[34567]86-*-sysv4.2*
5503 i[34567]86-*-unixware2*
5504 i[34567]86-*-unixware*
5513 * Other removed features
5520 Various m68k-only ROM monitors.
5527 Various Renesas ROM monitors and debugging interfaces for SH and
5532 Support for a Macraigor serial interface to on-chip debugging.
5533 GDB does not directly support the newer parallel or USB
5538 A debug information format. The predecessor to DWARF 2 and
5539 DWARF 3, which are still supported.
5541 Support for the HP aCC compiler on HP-UX/PA-RISC
5543 SOM-encapsulated symbolic debugging information, automatic
5544 invocation of pxdb, and the aCC custom C++ ABI. This does not
5545 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5546 with aCC can still be debugged on an assembly level.
5548 MIPS ".pdr" sections
5550 A MIPS-specific format used to describe stack frame layout
5551 in debugging information.
5555 GDB could work with an older version of Guile to debug
5556 the interpreter and Scheme programs running in it.
5558 set mips stack-arg-size
5559 set mips saved-gpreg-size
5561 Use "set mips abi" to control parameter passing for MIPS.
5563 *** Changes in GDB 6.6
5568 Cell Broadband Engine SPU spu-elf
5570 * GDB can now be configured as a cross-debugger targeting native Windows
5571 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5572 running on a Windows system over TCP/IP to debug Windows programs.
5574 * The GDB remote stub, gdbserver, has been updated to support Windows and
5575 Cygwin debugging. Both single-threaded and multi-threaded programs are
5578 * The "set trust-readonly-sections" command works again. This command was
5579 broken in GDB 6.3, 6.4, and 6.5.
5581 * The "load" command now supports writing to flash memory, if the remote
5582 stub provides the required support.
5584 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5585 longer requires symbolic debug information (e.g. DWARF-2).
5590 unset substitute-path
5591 show substitute-path
5592 Manage a list of substitution rules that GDB uses to rewrite the name
5593 of the directories where the sources are located. This can be useful
5594 for instance when the sources were moved to a different location
5595 between compilation and debugging.
5599 Print each CLI command as it is executed. Each command is prefixed with
5600 a number of `+' symbols representing the nesting depth.
5601 The source command now has a `-v' option to enable the same feature.
5605 The ARM Demon monitor support (RDP protocol, "target rdp").
5607 Kernel Object Display, an embedded debugging feature which only worked with
5608 an obsolete version of Cisco IOS.
5610 The 'set download-write-size' and 'show download-write-size' commands.
5612 * New remote packets
5615 Tell a stub about GDB client features, and request remote target features.
5616 The first feature implemented is PacketSize, which allows the target to
5617 specify the size of packets it can handle - to minimize the number of
5618 packets required and improve performance when connected to a remote
5622 Fetch an OS auxilliary vector from the remote stub. This packet is a
5623 more efficient replacement for qPart:auxv:read.
5625 qXfer:memory-map:read:
5626 Fetch a memory map from the remote stub, including information about
5627 RAM, ROM, and flash memory devices.
5632 Erase and program a flash memory device.
5634 * Removed remote packets
5637 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5638 used it, and only gdbserver implemented it.
5640 *** Changes in GDB 6.5
5644 Renesas M32C/M16C m32c-elf
5646 Morpho Technologies ms1 ms1-elf
5650 init-if-undefined Initialize a convenience variable, but
5651 only if it doesn't already have a value.
5653 The following commands are presently only implemented for native GNU/Linux:
5655 checkpoint Save a snapshot of the program state.
5657 restart <n> Return the program state to a
5658 previously saved state.
5660 info checkpoints List currently saved checkpoints.
5662 delete-checkpoint <n> Delete a previously saved checkpoint.
5664 set|show detach-on-fork Tell gdb whether to detach from a newly
5665 forked process, or to keep debugging it.
5667 info forks List forks of the user program that
5668 are available to be debugged.
5670 fork <n> Switch to debugging one of several
5671 forks of the user program that are
5672 available to be debugged.
5674 delete-fork <n> Delete a fork from the list of forks
5675 that are available to be debugged (and
5676 kill the forked process).
5678 detach-fork <n> Delete a fork from the list of forks
5679 that are available to be debugged (and
5680 allow the process to continue).
5684 Morpho Technologies ms2 ms1-elf
5686 * Improved Windows host support
5688 GDB now builds as a cross debugger hosted on i686-mingw32, including
5689 native console support, and remote communications using either
5690 network sockets or serial ports.
5692 * Improved Modula-2 language support
5694 GDB can now print most types in the Modula-2 syntax. This includes:
5695 basic types, set types, record types, enumerated types, range types,
5696 pointer types and ARRAY types. Procedure var parameters are correctly
5697 printed and hexadecimal addresses and character constants are also
5698 written in the Modula-2 syntax. Best results can be obtained by using
5699 GNU Modula-2 together with the -gdwarf-2 command line option.
5703 The ARM rdi-share module.
5705 The Netware NLM debug server.
5707 *** Changes in GDB 6.4
5709 * New native configurations
5711 OpenBSD/arm arm*-*-openbsd*
5712 OpenBSD/mips64 mips64-*-openbsd*
5716 Morpho Technologies ms1 ms1-elf
5718 * New command line options
5720 --batch-silent As for --batch, but totally silent.
5721 --return-child-result The debugger will exist with the same value
5722 the child (debugged) program exited with.
5723 --eval-command COMMAND, -ex COMMAND
5724 Execute a single GDB CLI command. This may be
5725 specified multiple times and in conjunction
5726 with the --command (-x) option.
5728 * Deprecated commands removed
5730 The following commands, that were deprecated in 2000, have been
5734 set|show arm disassembly-flavor set|show arm disassembler
5735 othernames set arm disassembler
5736 set|show remotedebug set|show debug remote
5737 set|show archdebug set|show debug arch
5738 set|show eventdebug set|show debug event
5741 * New BSD user-level threads support
5743 It is now possible to debug programs using the user-level threads
5744 library on OpenBSD and FreeBSD. Currently supported (target)
5747 FreeBSD/amd64 x86_64-*-freebsd*
5748 FreeBSD/i386 i386-*-freebsd*
5749 OpenBSD/i386 i386-*-openbsd*
5751 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5752 are not yet supported.
5754 * New support for Matsushita MN10300 w/sim added
5755 (Work in progress). mn10300-elf.
5757 * REMOVED configurations and files
5759 VxWorks and the XDR protocol *-*-vxworks
5760 Motorola MCORE mcore-*-*
5761 National Semiconductor NS32000 ns32k-*-*
5763 * New "set print array-indexes" command
5765 After turning this setting "on", GDB prints the index of each element
5766 when displaying arrays. The default is "off" to preserve the previous
5769 * VAX floating point support
5771 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5773 * User-defined command support
5775 In addition to using $arg0..$arg9 for argument passing, it is now possible
5776 to use $argc to determine now many arguments have been passed. See the
5777 section on user-defined commands in the user manual for more information.
5779 *** Changes in GDB 6.3:
5781 * New command line option
5783 GDB now accepts -l followed by a number to set the timeout for remote
5786 * GDB works with GCC -feliminate-dwarf2-dups
5788 GDB now supports a more compact representation of DWARF-2 debug
5789 information using DW_FORM_ref_addr references. These are produced
5790 by GCC with the option -feliminate-dwarf2-dups and also by some
5791 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5792 to use -feliminate-dwarf2-dups.
5794 * Internationalization
5796 When supported by the host system, GDB will be built with
5797 internationalization (libintl). The task of marking up the sources is
5798 continued, we're looking forward to our first translation.
5802 Initial support for debugging programs compiled with the GNAT
5803 implementation of the Ada programming language has been integrated
5804 into GDB. In this release, support is limited to expression evaluation.
5806 * New native configurations
5808 GNU/Linux/m32r m32r-*-linux-gnu
5812 GDB's remote protocol now includes support for the 'p' packet. This
5813 packet is used to fetch individual registers from a remote inferior.
5815 * END-OF-LIFE registers[] compatibility module
5817 GDB's internal register infrastructure has been completely rewritten.
5818 The new infrastructure making possible the implementation of key new
5819 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5822 GDB 6.3 will be the last release to include the registers[]
5823 compatibility module that allowed out-of-date configurations to
5824 continue to work. This change directly impacts the following
5834 powerpc bdm protocol
5836 Unless there is activity to revive these configurations, they will be
5837 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5839 * OBSOLETE configurations and files
5841 Configurations that have been declared obsolete in this release have
5842 been commented out. Unless there is activity to revive these
5843 configurations, the next release of GDB will have their sources
5844 permanently REMOVED.
5853 *** Changes in GDB 6.2.1:
5855 * MIPS `break main; run' gave an heuristic-fence-post warning
5857 When attempting to run even a simple program, a warning about
5858 heuristic-fence-post being hit would be reported. This problem has
5861 * MIPS IRIX 'long double' crashed GDB
5863 When examining a long double variable, GDB would get a segmentation
5864 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5865 IRIX long double values).
5869 A bug in the VAX stack code was causing problems with the "next"
5870 command. This problem has been fixed.
5872 *** Changes in GDB 6.2:
5874 * Fix for ``many threads''
5876 On GNU/Linux systems that use the NPTL threads library, a program
5877 rapidly creating and deleting threads would confuse GDB leading to the
5880 ptrace: No such process.
5881 thread_db_get_info: cannot get thread info: generic error
5883 This problem has been fixed.
5885 * "-async" and "-noasync" options removed.
5887 Support for the broken "-noasync" option has been removed (it caused
5890 * New ``start'' command.
5892 This command runs the program until the beginning of the main procedure.
5894 * New BSD Kernel Data Access Library (libkvm) interface
5896 Using ``target kvm'' it is now possible to debug kernel core dumps and
5897 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5898 platforms. Currently supported (native-only) configurations are:
5900 FreeBSD/amd64 x86_64-*-freebsd*
5901 FreeBSD/i386 i?86-*-freebsd*
5902 NetBSD/i386 i?86-*-netbsd*
5903 NetBSD/m68k m68*-*-netbsd*
5904 NetBSD/sparc sparc-*-netbsd*
5905 OpenBSD/amd64 x86_64-*-openbsd*
5906 OpenBSD/i386 i?86-*-openbsd*
5907 OpenBSD/m68k m68*-openbsd*
5908 OpenBSD/sparc sparc-*-openbsd*
5910 * Signal trampoline code overhauled
5912 Many generic problems with GDB's signal handling code have been fixed.
5913 These include: backtraces through non-contiguous stacks; recognition
5914 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5915 call; backtrace through a signal trampoline; step into and out of
5916 signal handlers; and single-stepping in the signal trampoline.
5918 Please note that kernel bugs are a limiting factor here. These
5919 features have been shown to work on an s390 GNU/Linux system that
5920 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5922 * Cygwin support for DWARF 2 added.
5924 * New native configurations
5926 GNU/Linux/hppa hppa*-*-linux*
5927 OpenBSD/hppa hppa*-*-openbsd*
5928 OpenBSD/m68k m68*-*-openbsd*
5929 OpenBSD/m88k m88*-*-openbsd*
5930 OpenBSD/powerpc powerpc-*-openbsd*
5931 NetBSD/vax vax-*-netbsd*
5932 OpenBSD/vax vax-*-openbsd*
5934 * END-OF-LIFE frame compatibility module
5936 GDB's internal frame infrastructure has been completely rewritten.
5937 The new infrastructure making it possible to support key new features
5938 including DWARF 2 Call Frame Information. To aid in the task of
5939 migrating old configurations to this new infrastructure, a
5940 compatibility module, that allowed old configurations to continue to
5941 work, was also included.
5943 GDB 6.2 will be the last release to include this frame compatibility
5944 module. This change directly impacts the following configurations:
5954 Unless there is activity to revive these configurations, they will be
5955 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5957 * REMOVED configurations and files
5959 Sun 3, running SunOS 3 m68*-*-sunos3*
5960 Sun 3, running SunOS 4 m68*-*-sunos4*
5961 Sun 2, running SunOS 3 m68000-*-sunos3*
5962 Sun 2, running SunOS 4 m68000-*-sunos4*
5963 Motorola 680x0 running LynxOS m68*-*-lynxos*
5964 AT&T 3b1/Unix pc m68*-att-*
5965 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5966 decstation mips-dec-* mips-little-*
5967 riscos mips-*-riscos* mips-*-sysv*
5968 sonymips mips-sony-*
5969 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5971 *** Changes in GDB 6.1.1:
5973 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5975 The TUI (Text-mode User Interface) is now built as part of a default
5976 GDB configuration. It is enabled by either selecting the TUI with the
5977 command line option "-i=tui" or by running the separate "gdbtui"
5978 program. For more information on the TUI, see the manual "Debugging
5981 * Pending breakpoint support (also included in GDB 6.1)
5983 Support has been added to allow you to specify breakpoints in shared
5984 libraries that have not yet been loaded. If a breakpoint location
5985 cannot be found, and the "breakpoint pending" option is set to auto,
5986 GDB queries you if you wish to make the breakpoint pending on a future
5987 shared-library load. If and when GDB resolves the breakpoint symbol,
5988 the pending breakpoint is removed as one or more regular breakpoints
5991 Pending breakpoints are very useful for GCJ Java debugging.
5993 * Fixed ISO-C build problems
5995 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5996 non ISO-C code that stopped them being built using a more strict ISO-C
5997 compiler (e.g., IBM's C compiler).
5999 * Fixed build problem on IRIX 5
6001 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6002 wasn't able to compile compile on an IRIX 5 system.
6004 * Added execute permission to gdb/gdbserver/configure
6006 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6007 permission. This bug would cause configure to fail on a number of
6008 systems (Solaris, IRIX). Ref: server/519.
6010 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6012 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6013 has been updated to use constant array sizes.
6015 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6017 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6018 its generated DWARF Call Frame Info. This encoding was causing GDB to
6019 panic, that panic has been fixed. Ref: gdb/1628.
6021 * Fixed a problem when examining parameters in shared library code.
6023 When examining parameters in optimized shared library code generated
6024 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6025 not available''. GDB now correctly displays the variable's value.
6027 *** Changes in GDB 6.1:
6029 * Removed --with-mmalloc
6031 Support for the mmalloc memory manager has been removed, as it
6032 conflicted with the internal gdb byte cache.
6034 * Changes in AMD64 configurations
6036 The AMD64 target now includes the %cs and %ss registers. As a result
6037 the AMD64 remote protocol has changed; this affects the floating-point
6038 and SSE registers. If you rely on those registers for your debugging,
6039 you should upgrade gdbserver on the remote side.
6041 * Revised SPARC target
6043 The SPARC target has been completely revised, incorporating the
6044 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6045 support for LynxOS and SunOS 4 has been dropped. Calling functions
6046 from within GDB on operating systems with a non-executable stack
6047 (Solaris, OpenBSD) now works.
6051 GDB has a new C++ demangler which does a better job on the mangled
6052 names generated by current versions of g++. It also runs faster, so
6053 with this and other changes gdb should now start faster on large C++
6056 * DWARF 2 Location Expressions
6058 GDB support for location expressions has been extended to support function
6059 arguments and frame bases. Older versions of GDB could crash when they
6062 * C++ nested types and namespaces
6064 GDB's support for nested types and namespaces in C++ has been
6065 improved, especially if you use the DWARF 2 debugging format. (This
6066 is the default for recent versions of GCC on most platforms.)
6067 Specifically, if you have a class "Inner" defined within a class or
6068 namespace "Outer", then GDB realizes that the class's name is
6069 "Outer::Inner", not simply "Inner". This should greatly reduce the
6070 frequency of complaints about not finding RTTI symbols. In addition,
6071 if you are stopped at inside of a function defined within a namespace,
6072 GDB modifies its name lookup accordingly.
6074 * New native configurations
6076 NetBSD/amd64 x86_64-*-netbsd*
6077 OpenBSD/amd64 x86_64-*-openbsd*
6078 OpenBSD/alpha alpha*-*-openbsd*
6079 OpenBSD/sparc sparc-*-openbsd*
6080 OpenBSD/sparc64 sparc64-*-openbsd*
6082 * New debugging protocols
6084 M32R with SDI protocol m32r-*-elf*
6086 * "set prompt-escape-char" command deleted.
6088 The command "set prompt-escape-char" has been deleted. This command,
6089 and its very obscure effect on GDB's prompt, was never documented,
6090 tested, nor mentioned in the NEWS file.
6092 * OBSOLETE configurations and files
6094 Configurations that have been declared obsolete in this release have
6095 been commented out. Unless there is activity to revive these
6096 configurations, the next release of GDB will have their sources
6097 permanently REMOVED.
6099 Sun 3, running SunOS 3 m68*-*-sunos3*
6100 Sun 3, running SunOS 4 m68*-*-sunos4*
6101 Sun 2, running SunOS 3 m68000-*-sunos3*
6102 Sun 2, running SunOS 4 m68000-*-sunos4*
6103 Motorola 680x0 running LynxOS m68*-*-lynxos*
6104 AT&T 3b1/Unix pc m68*-att-*
6105 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6106 decstation mips-dec-* mips-little-*
6107 riscos mips-*-riscos* mips-*-sysv*
6108 sonymips mips-sony-*
6109 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6111 * REMOVED configurations and files
6113 SGI Irix-4.x mips-sgi-irix4 or iris4
6114 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6115 Z8000 simulator z8k-zilog-none or z8ksim
6116 Matsushita MN10200 w/simulator mn10200-*-*
6117 H8/500 simulator h8500-hitachi-hms or h8500hms
6118 HP/PA running BSD hppa*-*-bsd*
6119 HP/PA running OSF/1 hppa*-*-osf*
6120 HP/PA Pro target hppa*-*-pro*
6121 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6122 386BSD i[3456]86-*-bsd*
6123 Sequent family i[3456]86-sequent-sysv4*
6124 i[3456]86-sequent-sysv*
6125 i[3456]86-sequent-bsd*
6126 SPARC running LynxOS sparc-*-lynxos*
6127 SPARC running SunOS 4 sparc-*-sunos4*
6128 Tsqware Sparclet sparclet-*-*
6129 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6131 *** Changes in GDB 6.0:
6135 Support for debugging the Objective-C programming language has been
6136 integrated into GDB.
6138 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6140 DWARF 2's Call Frame Information makes available compiler generated
6141 information that more exactly describes the program's run-time stack.
6142 By using this information, GDB is able to provide more robust stack
6145 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6146 have been updated to use a new backtrace mechanism which includes
6147 DWARF 2 CFI support.
6151 GDB's remote protocol has been extended to include support for hosted
6152 file I/O (where the remote target uses GDB's file system). See GDB's
6153 remote protocol documentation for details.
6155 * All targets using the new architecture framework.
6157 All of GDB's targets have been updated to use the new internal
6158 architecture framework. The way is now open for future GDB releases
6159 to include cross-architecture native debugging support (i386 on amd64,
6162 * GNU/Linux's Thread Local Storage (TLS)
6164 GDB now includes support for for the GNU/Linux implementation of
6165 per-thread variables.
6167 * GNU/Linux's Native POSIX Thread Library (NPTL)
6169 GDB's thread code has been updated to work with either the new
6170 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6172 * Separate debug info.
6174 GDB, in conjunction with BINUTILS, now supports a mechanism for
6175 automatically loading debug information from a separate file. Instead
6176 of shipping full debug and non-debug versions of system libraries,
6177 system integrators can now instead ship just the stripped libraries
6178 and optional debug files.
6180 * DWARF 2 Location Expressions
6182 DWARF 2 Location Expressions allow the compiler to more completely
6183 describe the location of variables (even in optimized code) to the
6186 GDB now includes preliminary support for location expressions (support
6187 for DW_OP_piece is still missing).
6191 A number of long standing bugs that caused GDB to die while starting a
6192 Java application have been fixed. GDB's Java support is now
6193 considered "useable".
6195 * GNU/Linux support for fork, vfork, and exec.
6197 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6198 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6201 * GDB supports logging output to a file
6203 There are two new commands, "set logging" and "show logging", which can be
6204 used to capture GDB's output to a file.
6206 * The meaning of "detach" has changed for gdbserver
6208 The "detach" command will now resume the application, as documented. To
6209 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6212 * d10v, m68hc11 `regs' command deprecated
6214 The `info registers' command has been updated so that it displays the
6215 registers using a format identical to the old `regs' command.
6219 A new command, "maint set profile on/off", has been added. This command can
6220 be used to enable or disable profiling while running GDB, to profile a
6221 session or a set of commands. In addition there is a new configure switch,
6222 "--enable-profiling", which will cause GDB to be compiled with profiling
6223 data, for more informative profiling results.
6225 * Default MI syntax changed to "mi2".
6227 The default MI (machine interface) syntax, enabled by the command line
6228 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6229 "mi1", can be enabled by specifying the option "-i=mi1".
6231 Support for the original "mi0" syntax (included in GDB 5.0) has been
6234 Fix for gdb/192: removed extraneous space when displaying frame level.
6235 Fix for gdb/672: update changelist is now output in mi list format.
6236 Fix for gdb/702: a -var-assign that updates the value now shows up
6237 in a subsequent -var-update.
6239 * New native configurations.
6241 FreeBSD/amd64 x86_64-*-freebsd*
6243 * Multi-arched targets.
6245 HP/PA HPUX11 hppa*-*-hpux*
6246 Renesas M32R/D w/simulator m32r-*-elf*
6248 * OBSOLETE configurations and files
6250 Configurations that have been declared obsolete in this release have
6251 been commented out. Unless there is activity to revive these
6252 configurations, the next release of GDB will have their sources
6253 permanently REMOVED.
6255 Z8000 simulator z8k-zilog-none or z8ksim
6256 Matsushita MN10200 w/simulator mn10200-*-*
6257 H8/500 simulator h8500-hitachi-hms or h8500hms
6258 HP/PA running BSD hppa*-*-bsd*
6259 HP/PA running OSF/1 hppa*-*-osf*
6260 HP/PA Pro target hppa*-*-pro*
6261 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6262 Sequent family i[3456]86-sequent-sysv4*
6263 i[3456]86-sequent-sysv*
6264 i[3456]86-sequent-bsd*
6265 Tsqware Sparclet sparclet-*-*
6266 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6268 * REMOVED configurations and files
6271 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6272 IBM AIX PS/2 i[3456]86-*-aix
6273 i386 running Mach 3.0 i[3456]86-*-mach3*
6274 i386 running Mach i[3456]86-*-mach*
6275 i386 running OSF/1 i[3456]86-*osf1mk*
6276 HP/Apollo 68k Family m68*-apollo*-sysv*,
6278 m68*-hp-bsd*, m68*-hp-hpux*
6279 Argonaut Risc Chip (ARC) arc-*-*
6280 Mitsubishi D30V d30v-*-*
6281 Fujitsu FR30 fr30-*-elf*
6282 OS/9000 i[34]86-*-os9k
6283 I960 with MON960 i960-*-coff
6285 * MIPS $fp behavior changed
6287 The convenience variable $fp, for the MIPS, now consistently returns
6288 the address of the current frame's base. Previously, depending on the
6289 context, $fp could refer to either $sp or the current frame's base
6290 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6291 The GNU Source-Level Debugger''.
6293 *** Changes in GDB 5.3:
6295 * GNU/Linux shared library multi-threaded performance improved.
6297 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6298 `/proc', in preference to `ptrace' for memory reads. This may result
6299 in an improvement in the start-up time of multi-threaded, shared
6300 library applications when run under GDB. One GDB user writes: ``loads
6301 shared libs like mad''.
6303 * ``gdbserver'' now supports multi-threaded applications on some targets
6305 Support for debugging multi-threaded applications which use
6306 the GNU/Linux LinuxThreads package has been added for
6307 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6308 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6310 * GDB now supports C/C++ preprocessor macros.
6312 GDB now expands preprocessor macro invocations in C/C++ expressions,
6313 and provides various commands for showing macro definitions and how
6316 The new command `macro expand EXPRESSION' expands any macro
6317 invocations in expression, and shows the result.
6319 The new command `show macro MACRO-NAME' shows the definition of the
6320 macro named MACRO-NAME, and where it was defined.
6322 Most compilers don't include information about macros in the debugging
6323 information by default. In GCC 3.1, for example, you need to compile
6324 your program with the options `-gdwarf-2 -g3'. If the macro
6325 information is present in the executable, GDB will read it.
6327 * Multi-arched targets.
6329 DEC Alpha (partial) alpha*-*-*
6330 DEC VAX (partial) vax-*-*
6332 National Semiconductor NS32000 (partial) ns32k-*-*
6333 Motorola 68000 (partial) m68k-*-*
6334 Motorola MCORE mcore-*-*
6338 Fujitsu FRV architecture added by Red Hat frv*-*-*
6341 * New native configurations
6343 Alpha NetBSD alpha*-*-netbsd*
6344 SH NetBSD sh*-*-netbsdelf*
6345 MIPS NetBSD mips*-*-netbsd*
6346 UltraSPARC NetBSD sparc64-*-netbsd*
6348 * OBSOLETE configurations and files
6350 Configurations that have been declared obsolete in this release have
6351 been commented out. Unless there is activity to revive these
6352 configurations, the next release of GDB will have their sources
6353 permanently REMOVED.
6355 Mitsubishi D30V d30v-*-*
6356 OS/9000 i[34]86-*-os9k
6357 IBM AIX PS/2 i[3456]86-*-aix
6358 Fujitsu FR30 fr30-*-elf*
6359 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6360 Argonaut Risc Chip (ARC) arc-*-*
6361 i386 running Mach 3.0 i[3456]86-*-mach3*
6362 i386 running Mach i[3456]86-*-mach*
6363 i386 running OSF/1 i[3456]86-*osf1mk*
6364 HP/Apollo 68k Family m68*-apollo*-sysv*,
6366 m68*-hp-bsd*, m68*-hp-hpux*
6367 I960 with MON960 i960-*-coff
6369 * OBSOLETE languages
6371 CHILL, a Pascal like language used by telecommunications companies.
6373 * REMOVED configurations and files
6375 AMD 29k family via UDI a29k-amd-udi, udi29k
6376 A29K VxWorks a29k-*-vxworks
6377 AMD 29000 embedded, using EBMON a29k-none-none
6378 AMD 29000 embedded with COFF a29k-none-coff
6379 AMD 29000 embedded with a.out a29k-none-aout
6381 testsuite/gdb.hp/gdb.threads-hp/ directory
6383 * New command "set max-user-call-depth <nnn>"
6385 This command allows the user to limit the call depth of user-defined
6386 commands. The default is 1024.
6388 * Changes in FreeBSD/i386 native debugging.
6390 Support for the "generate-core-file" has been added.
6392 * New commands "dump", "append", and "restore".
6394 These commands allow data to be copied from target memory
6395 to a bfd-format or binary file (dump and append), and back
6396 from a file into memory (restore).
6398 * Improved "next/step" support on multi-processor Alpha Tru64.
6400 The previous single-step mechanism could cause unpredictable problems,
6401 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6402 of a software single-step mechanism prevents this.
6404 *** Changes in GDB 5.2.1:
6412 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6413 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6414 Fix, by Joel Brobecker imported from mainline.
6416 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6417 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6418 Fix, by Fred Fish, imported from mainline.
6420 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6421 Surprisingly enough, it works now.
6422 By Michal Ludvig, imported from mainline.
6424 i386 hardware watchpoint support:
6425 avoid misses on second run for some targets.
6426 By Pierre Muller, imported from mainline.
6428 *** Changes in GDB 5.2:
6430 * New command "set trust-readonly-sections on[off]".
6432 This command is a hint that tells gdb that read-only sections
6433 really are read-only (ie. that their contents will not change).
6434 In this mode, gdb will go to the object file rather than the
6435 target to read memory from read-only sections (such as ".text").
6436 This can be a significant performance improvement on some
6437 (notably embedded) targets.
6439 * New command "generate-core-file" (or "gcore").
6441 This new gdb command allows the user to drop a core file of the child
6442 process state at any time. So far it's been implemented only for
6443 GNU/Linux and Solaris, but should be relatively easily ported to other
6444 hosts. Argument is core file name (defaults to core.<pid>).
6446 * New command line option
6448 GDB now accepts --pid or -p followed by a process id.
6450 * Change in command line behavior -- corefiles vs. process ids.
6452 There is a subtle behavior in the way in which GDB handles
6453 command line arguments. The first non-flag argument is always
6454 a program to debug, but the second non-flag argument may either
6455 be a corefile or a process id. Previously, GDB would attempt to
6456 open the second argument as a corefile, and if that failed, would
6457 issue a superfluous error message and then attempt to attach it as
6458 a process. Now, if the second argument begins with a non-digit,
6459 it will be treated as a corefile. If it begins with a digit,
6460 GDB will attempt to attach it as a process, and if no such process
6461 is found, will then attempt to open it as a corefile.
6463 * Changes in ARM configurations.
6465 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6466 configuration is fully multi-arch.
6468 * New native configurations
6470 ARM NetBSD arm*-*-netbsd*
6471 x86 OpenBSD i[3456]86-*-openbsd*
6472 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6473 Sparc64 running FreeBSD sparc64-*-freebsd*
6477 Sanyo XStormy16 xstormy16-elf
6479 * OBSOLETE configurations and files
6481 Configurations that have been declared obsolete in this release have
6482 been commented out. Unless there is activity to revive these
6483 configurations, the next release of GDB will have their sources
6484 permanently REMOVED.
6486 AMD 29k family via UDI a29k-amd-udi, udi29k
6487 A29K VxWorks a29k-*-vxworks
6488 AMD 29000 embedded, using EBMON a29k-none-none
6489 AMD 29000 embedded with COFF a29k-none-coff
6490 AMD 29000 embedded with a.out a29k-none-aout
6492 testsuite/gdb.hp/gdb.threads-hp/ directory
6494 * REMOVED configurations and files
6496 TI TMS320C80 tic80-*-*
6498 PowerPC Solaris powerpcle-*-solaris*
6499 PowerPC Windows NT powerpcle-*-cygwin32
6500 PowerPC Netware powerpc-*-netware*
6501 Harris/CXUX m88k m88*-harris-cxux*
6502 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6503 ns32k-utek-sysv* ns32k-utek-*
6504 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6505 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6506 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6507 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6508 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6510 * Changes to command line processing
6512 The new `--args' feature can be used to specify command-line arguments
6513 for the inferior from gdb's command line.
6515 * Changes to key bindings
6517 There is a new `operate-and-get-next' function bound to `C-o'.
6519 *** Changes in GDB 5.1.1
6521 Fix compile problem on DJGPP.
6523 Fix a problem with floating-point registers on the i386 being
6526 Fix to stop GDB crashing on .debug_str debug info.
6528 Numerous documentation fixes.
6530 Numerous testsuite fixes.
6532 *** Changes in GDB 5.1:
6534 * New native configurations
6536 Alpha FreeBSD alpha*-*-freebsd*
6537 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6538 MIPS GNU/Linux mips*-*-linux*
6539 MIPS SGI Irix 6.x mips*-sgi-irix6*
6540 ia64 AIX ia64-*-aix*
6541 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6545 Motorola 68HC11 and 68HC12 m68hc11-elf
6547 UltraSparc running GNU/Linux sparc64-*-linux*
6549 * OBSOLETE configurations and files
6551 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6552 Harris/CXUX m88k m88*-harris-cxux*
6553 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6554 ns32k-utek-sysv* ns32k-utek-*
6555 TI TMS320C80 tic80-*-*
6557 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6558 PowerPC Solaris powerpcle-*-solaris*
6559 PowerPC Windows NT powerpcle-*-cygwin32
6560 PowerPC Netware powerpc-*-netware*
6561 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6562 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6563 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6564 Apple Macintosh (MPW) host N/A
6566 stuff.c (Program to stuff files into a specially prepared space in kdb)
6567 kdb-start.c (Main loop for the standalone kernel debugger)
6569 Configurations that have been declared obsolete in this release have
6570 been commented out. Unless there is activity to revive these
6571 configurations, the next release of GDB will have their sources
6572 permanently REMOVED.
6574 * REMOVED configurations and files
6576 Altos 3068 m68*-altos-*
6577 Convex c1-*-*, c2-*-*
6579 ARM RISCix arm-*-* (as host)
6583 * GDB has been converted to ISO C.
6585 GDB's source code has been converted to ISO C. In particular, the
6586 sources are fully protoized, and rely on standard headers being
6591 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6593 * The MI enabled by default.
6595 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6596 revised and enabled by default. Packages which use GDB as a debugging
6597 engine behind a UI or another front end are encouraged to switch to
6598 using the GDB/MI interface, instead of the old annotations interface
6599 which is now deprecated.
6601 * Support for debugging Pascal programs.
6603 GDB now includes support for debugging Pascal programs. The following
6604 main features are supported:
6606 - Pascal-specific data types such as sets;
6608 - automatic recognition of Pascal sources based on file-name
6611 - Pascal-style display of data types, variables, and functions;
6613 - a Pascal expression parser.
6615 However, some important features are not yet supported.
6617 - Pascal string operations are not supported at all;
6619 - there are some problems with boolean types;
6621 - Pascal type hexadecimal constants are not supported
6622 because they conflict with the internal variables format;
6624 - support for Pascal objects and classes is not full yet;
6626 - unlike Pascal, GDB is case-sensitive for symbol names.
6628 * Changes in completion.
6630 Commands such as `shell', `run' and `set args', which pass arguments
6631 to inferior programs, now complete on file names, similar to what
6632 users expect at the shell prompt.
6634 Commands which accept locations, such as `disassemble', `print',
6635 `breakpoint', `until', etc. now complete on filenames as well as
6636 program symbols. Thus, if you type "break foob TAB", and the source
6637 files linked into the programs include `foobar.c', that file name will
6638 be one of the candidates for completion. However, file names are not
6639 considered for completion after you typed a colon that delimits a file
6640 name from a name of a function in that file, as in "break foo.c:bar".
6642 `set demangle-style' completes on available demangling styles.
6644 * New platform-independent commands:
6646 It is now possible to define a post-hook for a command as well as a
6647 hook that runs before the command. For more details, see the
6648 documentation of `hookpost' in the GDB manual.
6650 * Changes in GNU/Linux native debugging.
6652 Support for debugging multi-threaded programs has been completely
6653 revised for all platforms except m68k and sparc. You can now debug as
6654 many threads as your system allows you to have.
6656 Attach/detach is supported for multi-threaded programs.
6658 Support for SSE registers was added for x86. This doesn't work for
6659 multi-threaded programs though.
6661 * Changes in MIPS configurations.
6663 Multi-arch support is enabled for all MIPS configurations.
6665 GDB can now be built as native debugger on SGI Irix 6.x systems for
6666 debugging n32 executables. (Debugging 64-bit executables is not yet
6669 * Unified support for hardware watchpoints in all x86 configurations.
6671 Most (if not all) native x86 configurations support hardware-assisted
6672 breakpoints and watchpoints in a unified manner. This support
6673 implements debug register sharing between watchpoints, which allows to
6674 put a virtually infinite number of watchpoints on the same address,
6675 and also supports watching regions up to 16 bytes with several debug
6678 The new maintenance command `maintenance show-debug-regs' toggles
6679 debugging print-outs in functions that insert, remove, and test
6680 watchpoints and hardware breakpoints.
6682 * Changes in the DJGPP native configuration.
6684 New command ``info dos sysinfo'' displays assorted information about
6685 the CPU, OS, memory, and DPMI server.
6687 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6688 display information about segment descriptors stored in GDT, LDT, and
6691 New commands ``info dos pde'' and ``info dos pte'' display entries
6692 from Page Directory and Page Tables (for now works with CWSDPMI only).
6693 New command ``info dos address-pte'' displays the Page Table entry for
6694 a given linear address.
6696 GDB can now pass command lines longer than 126 characters to the
6697 program being debugged (requires an update to the libdbg.a library
6698 which is part of the DJGPP development kit).
6700 DWARF2 debug info is now supported.
6702 It is now possible to `step' and `next' through calls to `longjmp'.
6704 * Changes in documentation.
6706 All GDB documentation was converted to GFDL, the GNU Free
6707 Documentation License.
6709 Tracepoints-related commands are now fully documented in the GDB
6712 TUI, the Text-mode User Interface, is now documented in the manual.
6714 Tracepoints-related commands are now fully documented in the GDB
6717 The "GDB Internals" manual now has an index. It also includes
6718 documentation of `ui_out' functions, GDB coding standards, x86
6719 hardware watchpoints, and memory region attributes.
6721 * GDB's version number moved to ``version.in''
6723 The Makefile variable VERSION has been replaced by the file
6724 ``version.in''. People creating GDB distributions should update the
6725 contents of this file.
6729 GUD support is now a standard part of the EMACS distribution.
6731 *** Changes in GDB 5.0:
6733 * Improved support for debugging FP programs on x86 targets
6735 Unified and much-improved support for debugging floating-point
6736 programs on all x86 targets. In particular, ``info float'' now
6737 displays the FP registers in the same format on all x86 targets, with
6738 greater level of detail.
6740 * Improvements and bugfixes in hardware-assisted watchpoints
6742 It is now possible to watch array elements, struct members, and
6743 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6744 on x86 targets no longer erroneously trigger when the address is
6747 * Improvements in the native DJGPP version of GDB
6749 The distribution now includes all the scripts and auxiliary files
6750 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6751 machines ``out of the box''.
6753 The DJGPP version can now debug programs that use signals. It is
6754 possible to catch signals that happened in the debuggee, deliver
6755 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6756 would kill the program being debugged.) Programs that hook hardware
6757 interrupts (keyboard, timer, etc.) can also be debugged.
6759 It is now possible to debug DJGPP programs that redirect their
6760 standard handles or switch them to raw (as opposed to cooked) mode, or
6761 even close them. The command ``run < foo > bar'' works as expected,
6762 and ``info terminal'' reports useful information about the debuggee's
6763 terminal, including raw/cooked mode, redirection, etc.
6765 The DJGPP version now uses termios functions for console I/O, which
6766 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6769 DOS-style file names with drive letters are now fully supported by
6772 It is now possible to debug DJGPP programs that switch their working
6773 directory. It is also possible to rerun the debuggee any number of
6774 times without restarting GDB; thus, you can use the same setup,
6775 breakpoints, etc. for many debugging sessions.
6777 * New native configurations
6779 ARM GNU/Linux arm*-*-linux*
6780 PowerPC GNU/Linux powerpc-*-linux*
6784 Motorola MCore mcore-*-*
6785 x86 VxWorks i[3456]86-*-vxworks*
6786 PowerPC VxWorks powerpc-*-vxworks*
6787 TI TMS320C80 tic80-*-*
6789 * OBSOLETE configurations
6791 Altos 3068 m68*-altos-*
6792 Convex c1-*-*, c2-*-*
6794 ARM RISCix arm-*-* (as host)
6797 Configurations that have been declared obsolete will be commented out,
6798 but the code will be left in place. If there is no activity to revive
6799 these configurations before the next release of GDB, the sources will
6800 be permanently REMOVED.
6802 * Gould support removed
6804 Support for the Gould PowerNode and NP1 has been removed.
6806 * New features for SVR4
6808 On SVR4 native platforms (such as Solaris), if you attach to a process
6809 without first loading a symbol file, GDB will now attempt to locate and
6810 load symbols from the running process's executable file.
6812 * Many C++ enhancements
6814 C++ support has been greatly improved. Overload resolution now works properly
6815 in almost all cases. RTTI support is on the way.
6817 * Remote targets can connect to a sub-program
6819 A popen(3) style serial-device has been added. This device starts a
6820 sub-process (such as a stand-alone simulator) and then communicates
6821 with that. The sub-program to run is specified using the syntax
6822 ``|<program> <args>'' vis:
6824 (gdb) set remotedebug 1
6825 (gdb) target extended-remote |mn10300-elf-sim program-args
6827 * MIPS 64 remote protocol
6829 A long standing bug in the mips64 remote protocol where by GDB
6830 expected certain 32 bit registers (ex SR) to be transfered as 32
6831 instead of 64 bits has been fixed.
6833 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6834 added to provide backward compatibility with older versions of GDB.
6836 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6838 The command ``set remotebinarydownload'' command has been replaced by
6839 ``set remote X-packet''. Other commands in ``set remote'' family
6840 include ``set remote P-packet''.
6842 * Breakpoint commands accept ranges.
6844 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6845 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6846 ``tracepoint passcount'' also accepts a range of tracepoints.
6848 * ``apropos'' command added.
6850 The ``apropos'' command searches through command names and
6851 documentation strings, printing out matches, making it much easier to
6852 try to find a command that does what you are looking for.
6856 A new machine oriented interface (MI) has been added to GDB. This
6857 interface is designed for debug environments running GDB as a separate
6858 process. This is part of the long term libGDB project. See the
6859 "GDB/MI" chapter of the GDB manual for further information. It can be
6860 enabled by configuring with:
6862 .../configure --enable-gdbmi
6864 *** Changes in GDB-4.18:
6866 * New native configurations
6868 HP-UX 10.20 hppa*-*-hpux10.20
6869 HP-UX 11.x hppa*-*-hpux11.0*
6870 M68K GNU/Linux m68*-*-linux*
6874 Fujitsu FR30 fr30-*-elf*
6875 Intel StrongARM strongarm-*-*
6876 Mitsubishi D30V d30v-*-*
6878 * OBSOLETE configurations
6880 Gould PowerNode, NP1 np1-*-*, pn-*-*
6882 Configurations that have been declared obsolete will be commented out,
6883 but the code will be left in place. If there is no activity to revive
6884 these configurations before the next release of GDB, the sources will
6885 be permanently REMOVED.
6889 As a compatibility experiment, GDB's source files buildsym.h and
6890 buildsym.c have been converted to pure standard C, no longer
6891 containing any K&R compatibility code. We believe that all systems in
6892 use today either come with a standard C compiler, or have a GCC port
6893 available. If this is not true, please report the affected
6894 configuration to bug-gdb@gnu.org immediately. See the README file for
6895 information about getting a standard C compiler if you don't have one
6900 GDB now uses readline 2.2.
6902 * set extension-language
6904 You can now control the mapping between filename extensions and source
6905 languages by using the `set extension-language' command. For instance,
6906 you can ask GDB to treat .c files as C++ by saying
6907 set extension-language .c c++
6908 The command `info extensions' lists all of the recognized extensions
6909 and their associated languages.
6911 * Setting processor type for PowerPC and RS/6000
6913 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6914 you can use the `set processor' command to specify what variant of the
6915 PowerPC family you are debugging. The command
6919 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6920 following PowerPC and RS6000 variants:
6922 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6923 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6925 403GC IBM PowerPC 403GC
6926 505 Motorola PowerPC 505
6927 860 Motorola PowerPC 860 or 850
6928 601 Motorola PowerPC 601
6929 602 Motorola PowerPC 602
6930 603 Motorola/IBM PowerPC 603 or 603e
6931 604 Motorola PowerPC 604 or 604e
6932 750 Motorola/IBM PowerPC 750 or 750
6934 At the moment, this command just tells GDB what to name the
6935 special-purpose processor registers. Since almost all the affected
6936 registers are inaccessible to user-level programs, this command is
6937 only useful for remote debugging in its present form.
6941 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6942 more extensive support for HP-UX. Added features include shared
6943 library support, kernel threads and hardware watchpoints for 11.00,
6944 support for HP's ANSI C and C++ compilers, and a compatibility mode
6945 for xdb and dbx commands.
6949 HP's donation includes the new concept of catchpoints, which is a
6950 generalization of the old catch command. On HP-UX, it is now possible
6951 to catch exec, fork, and vfork, as well as library loading.
6953 This means that the existing catch command has changed; its first
6954 argument now specifies the type of catch to be set up. See the
6955 output of "help catch" for a list of catchpoint types.
6957 * Debugging across forks
6959 On HP-UX, you can choose which process to debug when a fork() happens
6964 HP has donated a curses-based terminal user interface (TUI). To get
6965 it, build with --enable-tui. Although this can be enabled for any
6966 configuration, at present it only works for native HP debugging.
6968 * GDB remote protocol additions
6970 A new protocol packet 'X' that writes binary data is now available.
6971 Default behavior is to try 'X', then drop back to 'M' if the stub
6972 fails to respond. The settable variable `remotebinarydownload'
6973 allows explicit control over the use of 'X'.
6975 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6976 full 64-bit address. The command
6978 set remoteaddresssize 32
6980 can be used to revert to the old behaviour. For existing remote stubs
6981 the change should not be noticed, as the additional address information
6984 In order to assist in debugging stubs, you may use the maintenance
6985 command `packet' to send any text string to the stub. For instance,
6987 maint packet heythere
6989 sends the packet "$heythere#<checksum>". Note that it is very easy to
6990 disrupt a debugging session by sending the wrong packet at the wrong
6993 The compare-sections command allows you to compare section data on the
6994 target to what is in the executable file without uploading or
6995 downloading, by comparing CRC checksums.
6997 * Tracing can collect general expressions
6999 You may now collect general expressions at tracepoints. This requires
7000 further additions to the target-side stub; see tracepoint.c and
7001 doc/agentexpr.texi for further details.
7003 * mask-address variable for Mips
7005 For Mips targets, you may control the zeroing of the upper 32 bits of
7006 a 64-bit address by entering `set mask-address on'. This is mainly
7007 of interest to users of embedded R4xxx and R5xxx processors.
7009 * Higher serial baud rates
7011 GDB's serial code now allows you to specify baud rates 57600, 115200,
7012 230400, and 460800 baud. (Note that your host system may not be able
7013 to achieve all of these rates.)
7017 The i960 configuration now includes an initial implementation of a
7018 builtin simulator, contributed by Jim Wilson.
7021 *** Changes in GDB-4.17:
7023 * New native configurations
7025 Alpha GNU/Linux alpha*-*-linux*
7026 Unixware 2.x i[3456]86-unixware2*
7027 Irix 6.x mips*-sgi-irix6*
7028 PowerPC GNU/Linux powerpc-*-linux*
7029 PowerPC Solaris powerpcle-*-solaris*
7030 Sparc GNU/Linux sparc-*-linux*
7031 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7035 Argonaut Risc Chip (ARC) arc-*-*
7036 Hitachi H8/300S h8300*-*-*
7037 Matsushita MN10200 w/simulator mn10200-*-*
7038 Matsushita MN10300 w/simulator mn10300-*-*
7039 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7040 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7041 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7042 Mitsubishi D10V w/simulator d10v-*-*
7043 Mitsubishi M32R/D w/simulator m32r-*-elf*
7044 Tsqware Sparclet sparclet-*-*
7045 NEC V850 w/simulator v850-*-*
7047 * New debugging protocols
7049 ARM with RDI protocol arm*-*-*
7050 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7051 DDB and LSI variants of PMON protocol mips*-*-*
7052 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7053 PowerPC with SDS protocol powerpc{,le}-*-eabi
7054 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7058 All configurations can now understand and use the DWARF 2 debugging
7059 format. The choice is automatic, if the symbol file contains DWARF 2
7064 GDB now includes basic Java language support. This support is
7065 only useful with Java compilers that produce native machine code.
7067 * solib-absolute-prefix and solib-search-path
7069 For SunOS and SVR4 shared libraries, you may now set the prefix for
7070 loading absolute shared library symbol files, and the search path for
7071 locating non-absolute shared library symbol files.
7073 * Live range splitting
7075 GDB can now effectively debug code for which GCC has performed live
7076 range splitting as part of its optimization. See gdb/doc/LRS for
7077 more details on the expected format of the stabs information.
7081 GDB's support for the GNU Hurd, including thread debugging, has been
7082 updated to work with current versions of the Hurd.
7086 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7087 instruction set. ARM GDB automatically detects when Thumb
7088 instructions are in use, and adjusts disassembly and backtracing
7093 GDB's MIPS target configurations now handle the MIP16 16-bit
7098 GDB now includes support for overlays; if an executable has been
7099 linked such that multiple sections are based at the same address, GDB
7100 will decide which section to use for symbolic info. You can choose to
7101 control the decision manually, using overlay commands, or implement
7102 additional target-side support and use "overlay load-target" to bring
7103 in the overlay mapping. Do "help overlay" for more detail.
7107 The command "info symbol <address>" displays information about
7108 the symbol at the specified address.
7112 The standard remote protocol now includes an extension that allows
7113 asynchronous collection and display of trace data. This requires
7114 extensive support in the target-side debugging stub. Tracing mode
7115 includes a new interaction mode in GDB and new commands: see the
7116 file tracepoint.c for more details.
7120 Configurations for embedded MIPS now include a simulator contributed
7121 by Cygnus Solutions. The simulator supports the instruction sets
7122 of most MIPS variants.
7126 Sparc configurations may now include the ERC32 simulator contributed
7127 by the European Space Agency. The simulator is not built into
7128 Sparc targets by default; configure with --enable-sim to include it.
7132 For target configurations that may include multiple variants of a
7133 basic architecture (such as MIPS and SH), you may now set the
7134 architecture explicitly. "set arch" sets, "info arch" lists
7135 the possible architectures.
7137 *** Changes in GDB-4.16:
7139 * New native configurations
7141 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7142 M68K NetBSD m68k-*-netbsd*
7143 PowerPC AIX 4.x powerpc-*-aix*
7144 PowerPC MacOS powerpc-*-macos*
7145 PowerPC Windows NT powerpcle-*-cygwin32
7146 RS/6000 AIX 4.x rs6000-*-aix4*
7150 ARM with RDP protocol arm-*-*
7151 I960 with MON960 i960-*-coff
7152 MIPS VxWorks mips*-*-vxworks*
7153 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7154 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7156 Matra Sparclet sparclet-*-*
7160 The powerpc-eabi configuration now includes the PSIM simulator,
7161 contributed by Andrew Cagney, with assistance from Mike Meissner.
7162 PSIM is a very elaborate model of the PowerPC, including not only
7163 basic instruction set execution, but also details of execution unit
7164 performance and I/O hardware. See sim/ppc/README for more details.
7168 GDB now works with Solaris 2.5.
7170 * Windows 95/NT native
7172 GDB will now work as a native debugger on Windows 95 and Windows NT.
7173 To build it from source, you must use the "gnu-win32" environment,
7174 which uses a DLL to emulate enough of Unix to run the GNU tools.
7175 Further information, binaries, and sources are available at
7176 ftp.cygnus.com, under pub/gnu-win32.
7178 * dont-repeat command
7180 If a user-defined command includes the command `dont-repeat', then the
7181 command will not be repeated if the user just types return. This is
7182 useful if the command is time-consuming to run, so that accidental
7183 extra keystrokes don't run the same command many times.
7185 * Send break instead of ^C
7187 The standard remote protocol now includes an option to send a break
7188 rather than a ^C to the target in order to interrupt it. By default,
7189 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7191 * Remote protocol timeout
7193 The standard remote protocol includes a new variable `remotetimeout'
7194 that allows you to set the number of seconds before GDB gives up trying
7195 to read from the target. The default value is 2.
7197 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7199 By default GDB will automatically keep track of objects as they are
7200 loaded and unloaded by the dynamic linker. By using the command `set
7201 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7202 when shared library events occur, thus allowing you to set breakpoints
7203 in shared libraries which are explicitly loaded by the inferior.
7205 Note this feature does not work on hpux8. On hpux9 you must link
7206 /usr/lib/end.o into your program. This feature should work
7207 automatically on hpux10.
7209 * Irix 5.x hardware watchpoint support
7211 Irix 5 configurations now support the use of hardware watchpoints.
7213 * Mips protocol "SYN garbage limit"
7215 When debugging a Mips target using the `target mips' protocol, you
7216 may set the number of characters that GDB will ignore by setting
7217 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7218 every character. The default value is 1050.
7220 * Recording and replaying remote debug sessions
7222 If you set `remotelogfile' to the name of a file, gdb will write to it
7223 a recording of a remote debug session. This recording may then be
7224 replayed back to gdb using "gdbreplay". See gdbserver/README for
7225 details. This is useful when you have a problem with GDB while doing
7226 remote debugging; you can make a recording of the session and send it
7227 to someone else, who can then recreate the problem.
7229 * Speedups for remote debugging
7231 GDB includes speedups for downloading and stepping MIPS systems using
7232 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7233 and more efficient S-record downloading.
7235 * Memory use reductions and statistics collection
7237 GDB now uses less memory and reports statistics about memory usage.
7238 Try the `maint print statistics' command, for example.
7240 *** Changes in GDB-4.15:
7242 * Psymtabs for XCOFF
7244 The symbol reader for AIX GDB now uses partial symbol tables. This
7245 can greatly improve startup time, especially for large executables.
7247 * Remote targets use caching
7249 Remote targets now use a data cache to speed up communication with the
7250 remote side. The data cache could lead to incorrect results because
7251 it doesn't know about volatile variables, thus making it impossible to
7252 debug targets which use memory mapped I/O devices. `set remotecache
7253 off' turns the data cache off.
7255 * Remote targets may have threads
7257 The standard remote protocol now includes support for multiple threads
7258 in the target system, using new protocol commands 'H' and 'T'. See
7259 gdb/remote.c for details.
7263 If GDB is configured with `--enable-netrom', then it will include
7264 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7265 acts as though it is a bank of ROM on the target board, but you can
7266 write into it over the network. GDB's support consists only of
7267 support for fast loading into the emulated ROM; to debug, you must use
7268 another protocol, such as standard remote protocol. The usual
7269 sequence is something like
7271 target nrom <netrom-hostname>
7273 target remote <netrom-hostname>:1235
7277 GDB now includes support for the Apple Macintosh, as a host only. It
7278 may be run as either an MPW tool or as a standalone application, and
7279 it can debug through the serial port. All the usual GDB commands are
7280 available, but to the target command, you must supply "serial" as the
7281 device type instead of "/dev/ttyXX". See mpw-README in the main
7282 directory for more information on how to build. The MPW configuration
7283 scripts */mpw-config.in support only a few targets, and only the
7284 mips-idt-ecoff target has been tested.
7288 GDB configuration now uses autoconf. This is not user-visible,
7289 but does simplify configuration and building.
7293 GDB now supports hpux10.
7295 *** Changes in GDB-4.14:
7297 * New native configurations
7299 x86 FreeBSD i[345]86-*-freebsd
7300 x86 NetBSD i[345]86-*-netbsd
7301 NS32k NetBSD ns32k-*-netbsd
7302 Sparc NetBSD sparc-*-netbsd
7306 A29K VxWorks a29k-*-vxworks
7307 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7308 CPU32 EST-300 emulator m68*-*-est*
7309 PowerPC ELF powerpc-*-elf
7312 * Alpha OSF/1 support for procfs
7314 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7315 possible to attach to running processes. As the mounting of the /proc
7316 filesystem is optional on the Alpha, GDB automatically determines
7317 the availability of /proc during startup. This can lead to problems
7318 if /proc is unmounted after GDB has been started.
7320 * Arguments to user-defined commands
7322 User commands may accept up to 10 arguments separated by whitespace.
7323 Arguments are accessed within the user command via $arg0..$arg9. A
7326 print $arg0 + $arg1 + $arg2
7328 To execute the command use:
7331 Defines the command "adder" which prints the sum of its three arguments.
7332 Note the arguments are text substitutions, so they may reference variables,
7333 use complex expressions, or even perform inferior function calls.
7335 * New `if' and `while' commands
7337 This makes it possible to write more sophisticated user-defined
7338 commands. Both commands take a single argument, which is the
7339 expression to evaluate, and must be followed by the commands to
7340 execute, one per line, if the expression is nonzero, the list being
7341 terminated by the word `end'. The `if' command list may include an
7342 `else' word, which causes the following commands to be executed only
7343 if the expression is zero.
7345 * Fortran source language mode
7347 GDB now includes partial support for Fortran 77. It will recognize
7348 Fortran programs and can evaluate a subset of Fortran expressions, but
7349 variables and functions may not be handled correctly. GDB will work
7350 with G77, but does not yet know much about symbols emitted by other
7353 * Better HPUX support
7355 Most debugging facilities now work on dynamic executables for HPPAs
7356 running hpux9 or later. You can attach to running dynamically linked
7357 processes, but by default the dynamic libraries will be read-only, so
7358 for instance you won't be able to put breakpoints in them. To change
7359 that behavior do the following before running the program:
7365 This will cause the libraries to be mapped private and read-write.
7366 To revert to the normal behavior, do this:
7372 You cannot set breakpoints or examine data in the library until after
7373 the library is loaded if the function/data symbols do not have
7376 GDB can now also read debug symbols produced by the HP C compiler on
7377 HPPAs (sorry, no C++, Fortran or 68k support).
7379 * Target byte order now dynamically selectable
7381 You can choose which byte order to use with a target system, via the
7382 commands "set endian big" and "set endian little", and you can see the
7383 current setting by using "show endian". You can also give the command
7384 "set endian auto", in which case GDB will use the byte order
7385 associated with the executable. Currently, only embedded MIPS
7386 configurations support dynamic selection of target byte order.
7388 * New DOS host serial code
7390 This version uses DPMI interrupts to handle buffered I/O, so you
7391 no longer need to run asynctsr when debugging boards connected to
7394 *** Changes in GDB-4.13:
7396 * New "complete" command
7398 This lists all the possible completions for the rest of the line, if it
7399 were to be given as a command itself. This is intended for use by emacs.
7401 * Trailing space optional in prompt
7403 "set prompt" no longer adds a space for you after the prompt you set. This
7404 allows you to set a prompt which ends in a space or one that does not.
7406 * Breakpoint hit counts
7408 "info break" now displays a count of the number of times the breakpoint
7409 has been hit. This is especially useful in conjunction with "ignore"; you
7410 can ignore a large number of breakpoint hits, look at the breakpoint info
7411 to see how many times the breakpoint was hit, then run again, ignoring one
7412 less than that number, and this will get you quickly to the last hit of
7415 * Ability to stop printing at NULL character
7417 "set print null-stop" will cause GDB to stop printing the characters of
7418 an array when the first NULL is encountered. This is useful when large
7419 arrays actually contain only short strings.
7421 * Shared library breakpoints
7423 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7424 breakpoints in shared libraries before the executable is run.
7426 * Hardware watchpoints
7428 There is a new hardware breakpoint for the watch command for sparclite
7429 targets. See gdb/sparclite/hw_breakpoint.note.
7431 Hardware watchpoints are also now supported under GNU/Linux.
7435 Annotations have been added. These are for use with graphical interfaces,
7436 and are still experimental. Currently only gdba.el uses these.
7438 * Improved Irix 5 support
7440 GDB now works properly with Irix 5.2.
7442 * Improved HPPA support
7444 GDB now works properly with the latest GCC and GAS.
7446 * New native configurations
7448 Sequent PTX4 i[34]86-sequent-ptx4
7449 HPPA running OSF/1 hppa*-*-osf*
7450 Atari TT running SVR4 m68*-*-sysv4*
7451 RS/6000 LynxOS rs6000-*-lynxos*
7455 OS/9000 i[34]86-*-os9k
7456 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7459 * Hitachi SH7000 and E7000-PC ICE support
7461 There is now support for communicating with the Hitachi E7000-PC ICE.
7462 This is available automatically when GDB is configured for the SH.
7466 As usual, a variety of small fixes and improvements, both generic
7467 and configuration-specific. See the ChangeLog for more detail.
7469 *** Changes in GDB-4.12:
7471 * Irix 5 is now supported
7475 GDB-4.12 on the HPPA has a number of changes which make it unable
7476 to debug the output from the currently released versions of GCC and
7477 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7478 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7479 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7482 *** Changes in GDB-4.11:
7484 * User visible changes:
7488 The "set remotedebug" option is now consistent between the mips remote
7489 target, remote targets using the gdb-specific protocol, UDI (AMD's
7490 debug protocol for the 29k) and the 88k bug monitor. It is now an
7491 integer specifying a debug level (normally 0 or 1, but 2 means more
7492 debugging info for the mips target).
7494 * DEC Alpha native support
7496 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7497 debug info, but GDB works fairly well with the DEC compiler and should
7498 work with a future GCC release. See the README file for a few
7499 Alpha-specific notes.
7501 * Preliminary thread implementation
7503 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7505 * LynxOS native and target support for 386
7507 This release has been hosted on LynxOS 2.2, and also can be configured
7508 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7511 * Improvements in C++ mangling/demangling.
7513 This release has much better g++ debugging, specifically in name
7514 mangling/demangling, virtual function calls, print virtual table,
7515 call methods, ...etc.
7517 *** Changes in GDB-4.10:
7519 * User visible changes:
7521 Remote debugging using the GDB-specific (`target remote') protocol now
7522 supports the `load' command. This is only useful if you have some
7523 other way of getting the stub to the target system, and you can put it
7524 somewhere in memory where it won't get clobbered by the download.
7526 Filename completion now works.
7528 When run under emacs mode, the "info line" command now causes the
7529 arrow to point to the line specified. Also, "info line" prints
7530 addresses in symbolic form (as well as hex).
7532 All vxworks based targets now support a user settable option, called
7533 vxworks-timeout. This option represents the number of seconds gdb
7534 should wait for responses to rpc's. You might want to use this if
7535 your vxworks target is, perhaps, a slow software simulator or happens
7536 to be on the far side of a thin network line.
7540 This release contains support for using a DEC alpha as a GDB host for
7541 cross debugging. Native alpha debugging is not supported yet.
7544 *** Changes in GDB-4.9:
7548 This is the first GDB release which is accompanied by a matching testsuite.
7549 The testsuite requires installation of dejagnu, which should be available
7550 via ftp from most sites that carry GNU software.
7554 'Cfront' style demangling has had its name changed to 'ARM' style, to
7555 emphasize that it was written from the specifications in the C++ Annotated
7556 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7557 disclaimers, it still generated too much confusion with users attempting to
7558 use gdb with AT&T cfront.
7562 GDB now uses a standard remote interface to a simulator library.
7563 So far, the library contains simulators for the Zilog Z8001/2, the
7564 Hitachi H8/300, H8/500 and Super-H.
7566 * New targets supported
7568 H8/300 simulator h8300-hitachi-hms or h8300hms
7569 H8/500 simulator h8500-hitachi-hms or h8500hms
7570 SH simulator sh-hitachi-hms or sh
7571 Z8000 simulator z8k-zilog-none or z8ksim
7572 IDT MIPS board over serial line mips-idt-ecoff
7574 Cross-debugging to GO32 targets is supported. It requires a custom
7575 version of the i386-stub.c module which is integrated with the
7576 GO32 memory extender.
7578 * New remote protocols
7580 MIPS remote debugging protocol.
7582 * New source languages supported
7584 This version includes preliminary support for Chill, a Pascal like language
7585 used by telecommunications companies. Chill support is also being integrated
7586 into the GNU compiler, but we don't know when it will be publically available.
7589 *** Changes in GDB-4.8:
7591 * HP Precision Architecture supported
7593 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7594 version of this support was available as a set of patches from the
7595 University of Utah. GDB does not support debugging of programs
7596 compiled with the HP compiler, because HP will not document their file
7597 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7598 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7600 Many problems in the preliminary version have been fixed.
7602 * Faster and better demangling
7604 We have improved template demangling and fixed numerous bugs in the GNU style
7605 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7606 character types (wchar_t) are now supported. Demangling of each symbol is now
7607 only done once, and is cached when the symbol table for a file is read in.
7608 This results in a small increase in memory usage for C programs, a moderate
7609 increase in memory usage for C++ programs, and a fantastic speedup in
7612 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7613 from the specifications in the Annotated Reference Manual, which AT&T's
7614 compiler does not actually implement.
7616 * G++ multiple inheritance compiler problem
7618 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7619 inheritance lattices was reworked to properly discover ambiguities. We
7620 recently found an example which causes this new algorithm to fail in a
7621 very subtle way, producing bad debug information for those classes.
7622 The file 'gcc.patch' (in this directory) can be applied to gcc to
7623 circumvent the problem. A future GCC release will contain a complete
7626 The previous G++ debug info problem (mentioned below for the gdb-4.7
7627 release) is fixed in gcc version 2.3.2.
7629 * Improved configure script
7631 The `configure' script will now attempt to guess your system type if
7632 you don't supply a host system type. The old scheme of supplying a
7633 host system triplet is preferable over using this. All the magic is
7634 done in the new `config.guess' script. Examine it for details.
7636 We have also brought our configure script much more in line with the FSF's
7637 version. It now supports the --with-xxx options. In particular,
7638 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7639 The resulting GDB will not be able to read arbitrary object file formats --
7640 only the format ``expected'' to be used on the configured target system.
7641 We hope to make this the default in a future release.
7643 * Documentation improvements
7645 There's new internal documentation on how to modify GDB, and how to
7646 produce clean changes to the code. We implore people to read it
7647 before submitting changes.
7649 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7650 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7651 `info' files are also provided. To build `info' files from scratch,
7652 you will need the latest `makeinfo' release, which will be available in
7653 a future texinfo-X.Y release.
7655 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7656 We're not sure exactly which versions have this problem, but it has
7657 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7658 or better. If that isn't possible, there is a patch in
7659 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7660 around this problem.
7664 GDB now supports array constants that can be used in expressions typed in by
7665 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7666 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7669 The new directory `gdb/sparclite' contains a program that demonstrates
7670 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7672 * New native hosts supported
7674 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7675 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7677 * New targets supported
7679 AMD 29k family via UDI a29k-amd-udi or udi29k
7681 * New file formats supported
7683 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7684 HPUX core files, and SCO 3.2v2 core files.
7688 Attaching to processes now works again; thanks for the many bug reports.
7690 We have also stomped on a bunch of core dumps caused by
7691 printf_filtered("%s") problems.
7693 We eliminated a copyright problem on the rpc and ptrace header files
7694 for VxWorks, which was discovered at the last minute during the 4.7
7695 release. You should now be able to build a VxWorks GDB.
7697 You can now interrupt gdb while an attached process is running. This
7698 will cause the attached process to stop, and give control back to GDB.
7700 We fixed problems caused by using too many file descriptors
7701 for reading symbols from object files and libraries. This was
7702 especially a problem for programs that used many (~100) shared
7705 The `step' command now only enters a subroutine if there is line number
7706 information for the subroutine. Otherwise it acts like the `next'
7707 command. Previously, `step' would enter subroutines if there was
7708 any debugging information about the routine. This avoids problems
7709 when using `cc -g1' on MIPS machines.
7711 * Internal improvements
7713 GDB's internal interfaces have been improved to make it easier to support
7714 debugging of multiple languages in the future.
7716 GDB now uses a common structure for symbol information internally.
7717 Minimal symbols (derived from linkage symbols in object files), partial
7718 symbols (from a quick scan of debug information), and full symbols
7719 contain a common subset of information, making it easier to write
7720 shared code that handles any of them.
7722 * New command line options
7724 We now accept --silent as an alias for --quiet.
7728 The memory-mapped-malloc library is now licensed under the GNU Library
7729 General Public License.
7731 *** Changes in GDB-4.7:
7733 * Host/native/target split
7735 GDB has had some major internal surgery to untangle the support for
7736 hosts and remote targets. Now, when you configure GDB for a remote
7737 target, it will no longer load in all of the support for debugging
7738 local programs on the host. When fully completed and tested, this will
7739 ensure that arbitrary host/target combinations are possible.
7741 The primary conceptual shift is to separate the non-portable code in
7742 GDB into three categories. Host specific code is required any time GDB
7743 is compiled on that host, regardless of the target. Target specific
7744 code relates to the peculiarities of the target, but can be compiled on
7745 any host. Native specific code is everything else: it can only be
7746 built when the host and target are the same system. Child process
7747 handling and core file support are two common `native' examples.
7749 GDB's use of /proc for controlling Unix child processes is now cleaner.
7750 It has been split out into a single module under the `target_ops' vector,
7751 plus two native-dependent functions for each system that uses /proc.
7753 * New hosts supported
7755 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7756 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7757 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7759 * New targets supported
7761 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7762 68030 and CPU32 m68030-*-*, m68332-*-*
7764 * New native hosts supported
7766 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7767 (386bsd is not well tested yet)
7768 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7770 * New file formats supported
7772 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7773 supports reading of `a.out.adobe' object files, which are an a.out
7774 format extended with minimal information about multiple sections.
7778 `show copying' is the same as the old `info copying'.
7779 `show warranty' is the same as `info warrantee'.
7780 These were renamed for consistency. The old commands continue to work.
7782 `info handle' is a new alias for `info signals'.
7784 You can now define pre-command hooks, which attach arbitrary command
7785 scripts to any command. The commands in the hook will be executed
7786 prior to the user's command. You can also create a hook which will be
7787 executed whenever the program stops. See gdb.texinfo.
7791 We now deal with Cfront style name mangling, and can even extract type
7792 info from mangled symbols. GDB can automatically figure out which
7793 symbol mangling style your C++ compiler uses.
7795 Calling of methods and virtual functions has been improved as well.
7799 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7800 fixed. This was due to mishandling of the extra N_SO stabs output
7803 We also finally got Ultrix 4.2 running in house, and fixed core file
7804 support, with help from a dozen people on the net.
7806 John M. Farrell discovered that the reason that single-stepping was so
7807 slow on all of the Mips based platforms (primarily SGI and DEC) was
7808 that we were trying to demangle and lookup a symbol used for internal
7809 purposes on every instruction that was being stepped through. Changing
7810 the name of that symbol so that it couldn't be mistaken for a C++
7811 mangled symbol sped things up a great deal.
7813 Rich Pixley sped up symbol lookups in general by getting much smarter
7814 about when C++ symbol mangling is necessary. This should make symbol
7815 completion (TAB on the command line) much faster. It's not as fast as
7816 we'd like, but it's significantly faster than gdb-4.6.
7820 A new user controllable variable 'call_scratch_address' can
7821 specify the location of a scratch area to be used when GDB
7822 calls a function in the target. This is necessary because the
7823 usual method of putting the scratch area on the stack does not work
7824 in systems that have separate instruction and data spaces.
7826 We integrated changes to support the 29k UDI (Universal Debugger
7827 Interface), but discovered at the last minute that we didn't have all
7828 of the appropriate copyright paperwork. We are working with AMD to
7829 resolve this, and hope to have it available soon.
7833 We have sped up the remote serial line protocol, especially for targets
7834 with lots of registers. It now supports a new `expedited status' ('T')
7835 message which can be used in place of the existing 'S' status message.
7836 This allows the remote stub to send only the registers that GDB
7837 needs to make a quick decision about single-stepping or conditional
7838 breakpoints, eliminating the need to fetch the entire register set for
7839 each instruction being stepped through.
7841 The GDB remote serial protocol now implements a write-through cache for
7842 registers, only re-reading the registers if the target has run.
7844 There is also a new remote serial stub for SPARC processors. You can
7845 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7846 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7847 processor with a serial port.
7851 Configure.in files have become much easier to read and modify. A new
7852 `table driven' format makes it more obvious what configurations are
7853 supported, and what files each one uses.
7857 There is a new opcodes library which will eventually contain all of the
7858 disassembly routines and opcode tables. At present, it only contains
7859 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7860 disassembler (binutils/objdump) to share these routines.
7862 The libiberty library is now copylefted under the GNU Library General
7863 Public License. This allows more liberal use, and was done so libg++
7864 can use it. This makes no difference to GDB, since the Library License
7865 grants all the rights from the General Public License.
7869 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7870 reference to the stabs symbol info used by the debugger. It is (as far
7871 as we know) the only published document on this fascinating topic. We
7872 encourage you to read it, compare it to the stabs information on your
7873 system, and send improvements on the document in general (to
7874 bug-gdb@prep.ai.mit.edu).
7876 And, of course, many bugs have been fixed.
7879 *** Changes in GDB-4.6:
7881 * Better support for C++ function names
7883 GDB now accepts as input the "demangled form" of C++ overloaded function
7884 names and member function names, and can do command completion on such names
7885 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7886 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7887 Make use of command completion, it is your friend.
7889 GDB also now accepts a variety of C++ mangled symbol formats. They are
7890 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7891 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7892 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7893 for the list of formats.
7895 * G++ symbol mangling problem
7897 Recent versions of gcc have a bug in how they emit debugging information for
7898 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7899 directory) can be applied to gcc to fix the problem. Alternatively, if you
7900 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7901 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7902 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7905 * New 'maintenance' command
7907 All of the commands related to hacking GDB internals have been moved out of
7908 the main command set, and now live behind the 'maintenance' command. This
7909 can also be abbreviated as 'mt'. The following changes were made:
7911 dump-me -> maintenance dump-me
7912 info all-breakpoints -> maintenance info breakpoints
7913 printmsyms -> maintenance print msyms
7914 printobjfiles -> maintenance print objfiles
7915 printpsyms -> maintenance print psymbols
7916 printsyms -> maintenance print symbols
7918 The following commands are new:
7920 maintenance demangle Call internal GDB demangler routine to
7921 demangle a C++ link name and prints the result.
7922 maintenance print type Print a type chain for a given symbol
7924 * Change to .gdbinit file processing
7926 We now read the $HOME/.gdbinit file before processing the argv arguments
7927 (e.g. reading symbol files or core files). This allows global parameters to
7928 be set, which will apply during the symbol reading. The ./.gdbinit is still
7929 read after argv processing.
7931 * New hosts supported
7933 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7935 GNU/Linux support i386-unknown-linux or linux
7937 We are also including code to support the HP/PA running BSD and HPUX. This
7938 is almost guaranteed not to work, as we didn't have time to test or build it
7939 for this release. We are including it so that the more adventurous (or
7940 masochistic) of you can play with it. We also had major problems with the
7941 fact that the compiler that we got from HP doesn't support the -g option.
7944 * New targets supported
7946 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7948 * More smarts about finding #include files
7950 GDB now remembers the compilation directory for all include files, and for
7951 all files from which C is generated (like yacc and lex sources). This
7952 greatly improves GDB's ability to find yacc/lex sources, and include files,
7953 especially if you are debugging your program from a directory different from
7954 the one that contains your sources.
7956 We also fixed a bug which caused difficulty with listing and setting
7957 breakpoints in include files which contain C code. (In the past, you had to
7958 try twice in order to list an include file that you hadn't looked at before.)
7960 * Interesting infernals change
7962 GDB now deals with arbitrary numbers of sections, where the symbols for each
7963 section must be relocated relative to that section's landing place in the
7964 target's address space. This work was needed to support ELF with embedded
7965 stabs used by Solaris-2.0.
7967 * Bug fixes (of course!)
7969 There have been loads of fixes for the following things:
7970 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7971 i960, stabs, DOS(GO32), procfs, etc...
7973 See the ChangeLog for details.
7975 *** Changes in GDB-4.5:
7977 * New machines supported (host and target)
7979 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7981 SGI Irix-4.x mips-sgi-irix4 or iris4
7983 * New malloc package
7985 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7986 Mmalloc is capable of handling multiple heaps of memory. It is also
7987 capable of saving a heap to a file, and then mapping it back in later.
7988 This can be used to greatly speedup the startup of GDB by using a
7989 pre-parsed symbol table which lives in a mmalloc managed heap. For
7990 more details, please read mmalloc/mmalloc.texi.
7994 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7995 'help info proc' for details.
7997 * MIPS ecoff symbol table format
7999 The code that reads MIPS symbol table format is now supported on all hosts.
8000 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8003 * File name changes for MS-DOS
8005 Many files in the config directories have been renamed to make it easier to
8006 support GDB on MS-DOSe systems (which have very restrictive file name
8007 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8008 environment) is close to working but has some remaining problems. Note
8009 that debugging of DOS programs is not supported, due to limitations
8010 in the ``operating system'', but it can be used to host cross-debugging.
8012 * Cross byte order fixes
8014 Many fixes have been made to support cross debugging of Sparc and MIPS
8015 targets from hosts whose byte order differs.
8017 * New -mapped and -readnow options
8019 If memory-mapped files are available on your system through the 'mmap'
8020 system call, you can use the -mapped option on the `file' or
8021 `symbol-file' commands to cause GDB to write the symbols from your
8022 program into a reusable file. If the program you are debugging is
8023 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8024 Future GDB debugging sessions will notice the presence of this file,
8025 and will quickly map in symbol information from it, rather than reading
8026 the symbol table from the executable program. Using the '-mapped'
8027 option in a GDB `file' or `symbol-file' command has the same effect as
8028 starting GDB with the '-mapped' command-line option.
8030 You can cause GDB to read the entire symbol table immediately by using
8031 the '-readnow' option with any of the commands that load symbol table
8032 information (or on the GDB command line). This makes the command
8033 slower, but makes future operations faster.
8035 The -mapped and -readnow options are typically combined in order to
8036 build a `fred.syms' file that contains complete symbol information.
8037 A simple GDB invocation to do nothing but build a `.syms' file for future
8040 gdb -batch -nx -mapped -readnow programname
8042 The `.syms' file is specific to the host machine on which GDB is run.
8043 It holds an exact image of GDB's internal symbol table. It cannot be
8044 shared across multiple host platforms.
8046 * longjmp() handling
8048 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8049 siglongjmp() without losing control. This feature has not yet been ported to
8050 all systems. It currently works on many 386 platforms, all MIPS-based
8051 platforms (SGI, DECstation, etc), and Sun3/4.
8055 Preliminary work has been put in to support the new Solaris OS from Sun. At
8056 this time, it can control and debug processes, but it is not capable of
8061 As always, many many bug fixes. The major areas were with g++, and mipsread.
8062 People using the MIPS-based platforms should experience fewer mysterious
8063 crashes and trashed symbol tables.
8065 *** Changes in GDB-4.4:
8067 * New machines supported (host and target)
8069 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8071 BSD Reno on Vax vax-dec-bsd
8072 Ultrix on Vax vax-dec-ultrix
8074 * New machines supported (target)
8076 AMD 29000 embedded, using EBMON a29k-none-none
8080 GDB continues to improve its handling of C++. `References' work better.
8081 The demangler has also been improved, and now deals with symbols mangled as
8082 per the Annotated C++ Reference Guide.
8084 GDB also now handles `stabs' symbol information embedded in MIPS
8085 `ecoff' symbol tables. Since the ecoff format was not easily
8086 extensible to handle new languages such as C++, this appeared to be a
8087 good way to put C++ debugging info into MIPS binaries. This option
8088 will be supported in the GNU C compiler, version 2, when it is
8091 * New features for SVR4
8093 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8094 shared libraries. Debugging dynamically linked programs should present
8095 only minor differences from debugging statically linked programs.
8097 The `info proc' command will print out information about any process
8098 on an SVR4 system (including the one you are debugging). At the moment,
8099 it prints the address mappings of the process.
8101 If you bring up GDB on another SVR4 system, please send mail to
8102 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8104 * Better dynamic linking support in SunOS
8106 Reading symbols from shared libraries which contain debugging symbols
8107 now works properly. However, there remain issues such as automatic
8108 skipping of `transfer vector' code during function calls, which
8109 make it harder to debug code in a shared library, than to debug the
8110 same code linked statically.
8114 GDB is now using the latest `getopt' routines from the FSF. This
8115 version accepts the -- prefix for options with long names. GDB will
8116 continue to accept the old forms (-option and +option) as well.
8117 Various single letter abbreviations for options have been explicity
8118 added to the option table so that they won't get overshadowed in the
8119 future by other options that begin with the same letter.
8123 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8124 Many assorted bugs have been handled. Many more remain to be handled.
8125 See the various ChangeLog files (primarily in gdb and bfd) for details.
8128 *** Changes in GDB-4.3:
8130 * New machines supported (host and target)
8132 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8133 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8134 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8136 * Almost SCO Unix support
8138 We had hoped to support:
8139 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8140 (except for core file support), but we discovered very late in the release
8141 that it has problems with process groups that render gdb unusable. Sorry
8142 about that. I encourage people to fix it and post the fixes.
8144 * Preliminary ELF and DWARF support
8146 GDB can read ELF object files on System V Release 4, and can handle
8147 debugging records for C, in DWARF format, in ELF files. This support
8148 is preliminary. If you bring up GDB on another SVR4 system, please
8149 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8154 GDB now uses the latest `readline' library. One user-visible change
8155 is that two tabs will list possible command completions, which previously
8156 required typing M-? (meta-question mark, or ESC ?).
8160 The `stepi' bug that many of you noticed has been squashed.
8161 Many bugs in C++ have been handled. Many more remain to be handled.
8162 See the various ChangeLog files (primarily in gdb and bfd) for details.
8164 * State of the MIPS world (in case you wondered):
8166 GDB can understand the symbol tables emitted by the compilers
8167 supplied by most vendors of MIPS-based machines, including DEC. These
8168 symbol tables are in a format that essentially nobody else uses.
8170 Some versions of gcc come with an assembler post-processor called
8171 mips-tfile. This program is required if you want to do source-level
8172 debugging of gcc-compiled programs. I believe FSF does not ship
8173 mips-tfile with gcc version 1, but it will eventually come with gcc
8176 Debugging of g++ output remains a problem. g++ version 1.xx does not
8177 really support it at all. (If you're lucky, you should be able to get
8178 line numbers and stack traces to work, but no parameters or local
8179 variables.) With some work it should be possible to improve the
8182 When gcc version 2 is released, you will have somewhat better luck.
8183 However, even then you will get confusing results for inheritance and
8186 We will eventually provide full debugging of g++ output on
8187 DECstations. This will probably involve some kind of stabs-in-ecoff
8188 encapulation, but the details have not been worked out yet.
8191 *** Changes in GDB-4.2:
8193 * Improved configuration
8195 Only one copy of `configure' exists now, and it is not self-modifying.
8196 Porting BFD is simpler.
8200 The `step' and `next' commands now only stop at the first instruction
8201 of a source line. This prevents the multiple stops that used to occur
8202 in switch statements, for-loops, etc. `Step' continues to stop if a
8203 function that has debugging information is called within the line.
8207 Lots of small bugs fixed. More remain.
8209 * New host supported (not target)
8211 Intel 386 PC clone running Mach i386-none-mach
8214 *** Changes in GDB-4.1:
8216 * Multiple source language support
8218 GDB now has internal scaffolding to handle several source languages.
8219 It determines the type of each source file from its filename extension,
8220 and will switch expression parsing and number formatting to match the
8221 language of the function in the currently selected stack frame.
8222 You can also specifically set the language to be used, with
8223 `set language c' or `set language modula-2'.
8227 GDB now has preliminary support for the GNU Modula-2 compiler,
8228 currently under development at the State University of New York at
8229 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8230 continue through the fall of 1991 and into 1992.
8232 Other Modula-2 compilers are currently not supported, and attempting to
8233 debug programs compiled with them will likely result in an error as the
8234 symbol table is read. Feel free to work on it, though!
8236 There are hooks in GDB for strict type checking and range checking,
8237 in the `Modula-2 philosophy', but they do not currently work.
8241 GDB can now write to executable and core files (e.g. patch
8242 a variable's value). You must turn this switch on, specify
8243 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8244 by assigning a new value to a variable. Modifications take
8247 * Automatic SunOS shared library reading
8249 When you run your program, GDB automatically determines where its
8250 shared libraries (if any) have been loaded, and reads their symbols.
8251 The `share' command is no longer needed. This also works when
8252 examining core files.
8256 You can specify the number of lines that the `list' command shows.
8259 * New machines supported (host and target)
8261 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8262 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8263 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8265 * New hosts supported (not targets)
8267 IBM RT/PC: romp-ibm-aix or rtpc
8269 * New targets supported (not hosts)
8271 AMD 29000 embedded with COFF a29k-none-coff
8272 AMD 29000 embedded with a.out a29k-none-aout
8273 Ultracomputer remote kernel debug a29k-nyu-kern
8275 * New remote interfaces
8281 *** Changes in GDB-4.0:
8285 Wide output is wrapped at good places to make the output more readable.
8287 Gdb now supports cross-debugging from a host machine of one type to a
8288 target machine of another type. Communication with the target system
8289 is over serial lines. The ``target'' command handles connecting to the
8290 remote system; the ``load'' command will download a program into the
8291 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8292 also supports debugging of realtime processes running under VxWorks,
8293 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8294 stub on the target system.
8296 New CPUs supported include the AMD 29000 and Intel 960.
8298 GDB now reads object files and symbol tables via a ``binary file''
8299 library, which allows a single copy of GDB to debug programs of multiple
8300 object file types such as a.out and coff.
8302 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8303 refcard.dvi and refcard.ps are available to format it).
8306 * Control-Variable user interface simplified
8308 All variables that control the operation of the debugger can be set
8309 by the ``set'' command, and displayed by the ``show'' command.
8311 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8312 ``Show prompt'' produces the response:
8313 Gdb's prompt is new-gdb=>.
8315 What follows are the NEW set commands. The command ``help set'' will
8316 print a complete list of old and new set commands. ``help set FOO''
8317 will give a longer description of the variable FOO. ``show'' will show
8318 all of the variable descriptions and their current settings.
8320 confirm on/off: Enables warning questions for operations that are
8321 hard to recover from, e.g. rerunning the program while
8322 it is already running. Default is ON.
8324 editing on/off: Enables EMACS style command line editing
8325 of input. Previous lines can be recalled with
8326 control-P, the current line can be edited with control-B,
8327 you can search for commands with control-R, etc.
8330 history filename NAME: NAME is where the gdb command history
8331 will be stored. The default is .gdb_history,
8332 or the value of the environment variable
8335 history size N: The size, in commands, of the command history. The
8336 default is 256, or the value of the environment variable
8339 history save on/off: If this value is set to ON, the history file will
8340 be saved after exiting gdb. If set to OFF, the
8341 file will not be saved. The default is OFF.
8343 history expansion on/off: If this value is set to ON, then csh-like
8344 history expansion will be performed on
8345 command line input. The default is OFF.
8347 radix N: Sets the default radix for input and output. It can be set
8348 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8349 in the current radix, so "set radix 10" is always a no-op.
8351 height N: This integer value is the number of lines on a page. Default
8352 is 24, the current `stty rows'' setting, or the ``li#''
8353 setting from the termcap entry matching the environment
8356 width N: This integer value is the number of characters on a line.
8357 Default is 80, the current `stty cols'' setting, or the ``co#''
8358 setting from the termcap entry matching the environment
8361 Note: ``set screensize'' is obsolete. Use ``set height'' and
8362 ``set width'' instead.
8364 print address on/off: Print memory addresses in various command displays,
8365 such as stack traces and structure values. Gdb looks
8366 more ``symbolic'' if you turn this off; it looks more
8367 ``machine level'' with it on. Default is ON.
8369 print array on/off: Prettyprint arrays. New convenient format! Default
8372 print demangle on/off: Print C++ symbols in "source" form if on,
8375 print asm-demangle on/off: Same, for assembler level printouts
8378 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8381 * Support for Epoch Environment.
8383 The epoch environment is a version of Emacs v18 with windowing. One
8384 new command, ``inspect'', is identical to ``print'', except that if you
8385 are running in the epoch environment, the value is printed in its own
8389 * Support for Shared Libraries
8391 GDB can now debug programs and core files that use SunOS shared libraries.
8392 Symbols from a shared library cannot be referenced
8393 before the shared library has been linked with the program (this
8394 happens after you type ``run'' and before the function main() is entered).
8395 At any time after this linking (including when examining core files
8396 from dynamically linked programs), gdb reads the symbols from each
8397 shared library when you type the ``sharedlibrary'' command.
8398 It can be abbreviated ``share''.
8400 sharedlibrary REGEXP: Load shared object library symbols for files
8401 matching a unix regular expression. No argument
8402 indicates to load symbols for all shared libraries.
8404 info sharedlibrary: Status of loaded shared libraries.
8409 A watchpoint stops execution of a program whenever the value of an
8410 expression changes. Checking for this slows down execution
8411 tremendously whenever you are in the scope of the expression, but is
8412 quite useful for catching tough ``bit-spreader'' or pointer misuse
8413 problems. Some machines such as the 386 have hardware for doing this
8414 more quickly, and future versions of gdb will use this hardware.
8416 watch EXP: Set a watchpoint (breakpoint) for an expression.
8418 info watchpoints: Information about your watchpoints.
8420 delete N: Deletes watchpoint number N (same as breakpoints).
8421 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8422 enable N: Re-enables watchpoint number N (same as breakpoints).
8425 * C++ multiple inheritance
8427 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8430 * C++ exception handling
8432 Gdb now supports limited C++ exception handling. Besides the existing
8433 ability to breakpoint on an exception handler, gdb can breakpoint on
8434 the raising of an exception (before the stack is peeled back to the
8437 catch FOO: If there is a FOO exception handler in the dynamic scope,
8438 set a breakpoint to catch exceptions which may be raised there.
8439 Multiple exceptions (``catch foo bar baz'') may be caught.
8441 info catch: Lists all exceptions which may be caught in the
8442 current stack frame.
8445 * Minor command changes
8447 The command ``call func (arg, arg, ...)'' now acts like the print
8448 command, except it does not print or save a value if the function's result
8449 is void. This is similar to dbx usage.
8451 The ``up'' and ``down'' commands now always print the frame they end up
8452 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8453 frames without printing.
8455 * New directory command
8457 'dir' now adds directories to the FRONT of the source search path.
8458 The path starts off empty. Source files that contain debug information
8459 about the directory in which they were compiled can be found even
8460 with an empty path; Sun CC and GCC include this information. If GDB can't
8461 find your source file in the current directory, type "dir .".
8463 * Configuring GDB for compilation
8465 For normal use, type ``./configure host''. See README or gdb.texinfo
8468 GDB now handles cross debugging. If you are remotely debugging between
8469 two different machines, type ``./configure host -target=targ''.
8470 Host is the machine where GDB will run; targ is the machine
8471 where the program that you are debugging will run.