1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 11
8 maint set backtrace-on-fatal-signal on|off
9 maint show backtrace-on-fatal-signal
10 This setting is 'on' by default. When 'on' GDB will print a limited
11 backtrace to stderr in the situation where GDB terminates with a
12 fatal signal. This only supported on some platforms where the
13 backtrace and backtrace_symbols_fd functions are available.
15 set source open on|off
17 This setting, which is on by default, controls whether GDB will try
18 to open source code files. Switching this off will stop GDB trying
19 to open and read source code files, which can be useful if the files
20 are located over a slow network connection.
24 These are now deprecated aliases for "set max-value-size" and
25 "show max-value-size".
27 maint set internal-error backtrace on|off
28 maint show internal-error backtrace
29 maint set internal-warning backtrace on|off
30 maint show internal-warning backtrace
31 GDB can now print a backtrace of itself when it encounters either an
32 internal-error, or an internal-warning. This is on by default for
33 internal-error and off by default for internal-warning.
36 Deprecated and replaced by "set logging enabled on|off".
38 set logging enabled on|off
40 These commands set or show whether logging is enabled or disabled.
45 This command can now print a reply, if the reply includes
46 non-printable characters. Any non-printable characters are printed
47 as escaped hex, e.g. \x?? where '??' is replaces with the value of
48 the non-printable character.
52 ** New function gdb.add_history(), which takes a gdb.Value object
53 and adds the value it represents to GDB's history list. An
54 integer, the index of the new item in the history list, is
57 ** New gdb.events.gdb_exiting event. This event is called with a
58 gdb.GdbExitingEvent object which has the read-only attribute
59 'exit_code', which contains the value of the GDB exit code. This
60 event is triggered once GDB decides it is going to exit, but
61 before GDB starts to clean up its internal state.
63 ** New function gdb.architecture_names(), which returns a list
64 containing all of the possible Architecture.name() values. Each
67 ** New function gdb.Architecture.integer_type(), which returns an
68 integer type given a size and a signed-ness.
70 ** New gdb.TargetConnection object type that represents a connection
71 (as displayed by the 'info connections' command). A sub-class,
72 gdb.RemoteTargetConnection, is used to represent 'remote' and
73 'extended-remote' connections.
75 ** The gdb.Inferior type now has a 'connection' property which is an
76 instance of gdb.TargetConnection, the connection used by this
77 inferior. This can be None if the inferior has no connection.
79 ** New 'gdb.events.connection_removed' event registry, which emits a
80 'gdb.ConnectionEvent' when a connection is removed from GDB.
81 This event has a 'connection' property, a gdb.TargetConnection
82 object for the connection being removed.
84 ** New gdb.connections() function that returns a list of all
85 currently active connections.
87 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
88 is equivalent to the existing 'maint packet' CLI command; it
89 allows a user specified packet to be sent to the remote target.
91 * New features in the GDB remote stub, GDBserver
93 ** GDBserver is now supported on OpenRISC GNU/Linux.
95 * New native configurations
97 GNU/Linux/OpenRISC or1k*-*-linux*
101 * The 'set disassembler-options' command now supports specifying options
104 * GDB now supports general memory tagging functionality if the underlying
105 architecture supports the proper primitives and hooks. Currently this is
106 enabled only for AArch64 MTE.
110 - Additional information when the inferior crashes with a SIGSEGV caused by
111 a memory tag violation.
113 - A new modifier 'm' for the "x" command, which displays allocation tags for a
114 particular memory range.
116 - Display of memory tag mismatches by "print", for addresses and
117 pointers, if memory tagging is supported by the architecture.
119 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
124 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
126 The MI -break-insert and -dprintf-insert commands now support a
127 new "--qualified" option that makes GDB interpret a specified
128 function name as a complete fully-qualified name. This is the
129 equivalent of the CLI's "break -qualified" and "dprintf
132 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
134 The MI -break-insert and -dprintf-insert commands now support a
135 '--force-condition' flag to forcibly define a condition even when
136 the condition is invalid at all locations of the breakpoint. This
137 is equivalent to the '-force-condition' flag of the CLI's "break"
140 ** '-break-condition --force'
142 The MI -break-condition command now supports a '--force' flag to
143 forcibly define a condition even when the condition is invalid at
144 all locations of the selected breakpoint. This is equivalent to
145 the '-force' flag of the CLI's "cond" command.
147 ** '-file-list-exec-source-files [--group-by-objfile]
148 [--basename | --dirname]
151 The existing -file-list-exec-source-files command now takes an
152 optional REGEXP which is used to filter the source files that are
153 included in the results.
155 By default REGEXP is matched against the full filename of the
156 source file. When one of --basename or --dirname is given then
157 REGEXP is only matched against the specified part of the full
160 When the optional --group-by-objfile flag is used the output
161 format is changed, the results are now a list of object files
162 (executable and libraries) with the source files that are
163 associated with each object file.
165 The results from -file-list-exec-source-files now include a
166 'debug-fully-read' field which takes the value 'true' or 'false'.
167 A 'true' value indicates the source file is from a compilation
168 unit that has had its debug information fully read in by GDB, a
169 value of 'false' indicates GDB has only performed a partial scan
170 of the debug information so far.
172 * GDB now supports core file debugging for x86_64 Cygwin programs.
174 * GDB will now look for the .gdbinit file in a config directory before
175 looking for ~/.gdbinit. The file is searched for in the following
176 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
177 $HOME/.gdbinit. On Apple hosts the search order is instead:
178 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
180 * GDB now supports fixed point types which are described in DWARF
181 as base types with a fixed-point encoding. Additionally, support
182 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
185 For Ada, this allows support for fixed point types without requiring
186 the use of the GNAT encoding (based on information added to the type's
187 name following a GNAT-specific format).
189 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
190 or ~/.gdbearlyinit if these files are present. These files are
191 processed earlier than any of the other initialization files and
192 can affect parts of GDB's startup that previously had already been
193 completed before the initialization files were read, for example
194 styling of the initial GDB greeting.
196 * GDB now has two new options "--early-init-command" and
197 "--early-init-eval-command" with corresponding short options "-eix"
198 and "-eiex" that allow options (that would normally appear in a
199 gdbearlyinit file) to be passed on the command line.
201 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
202 now understood by GDB, and can be used to describe the vector
203 registers of a target. The precise requirements of this register
204 feature are documented in the GDB manual.
206 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
207 supported by GDB and describes a new VPR register from the ARM MVE
208 (Helium) extension. See the GDB manual for more information.
212 ** TUI windows now support mouse actions. The mouse wheel scrolls
213 the appropriate window.
215 ** Key combinations that do not have a specific action on the
216 focused window are passed to GDB. For example, you now can use
217 Ctrl-Left/Ctrl-Right to move between words in the command window
218 regardless of which window is in focus. Previously you would
219 need to focus on the command window for such key combinations to
225 show debug event-loop
226 Control the display of debug output about GDB's event loop.
228 set print memory-tag-violations
229 show print memory-tag-violations
230 Control whether to display additional information about memory tag violations
231 when printing pointers and addresses. Architecture support for memory
232 tagging is required for this option to have an effect.
234 maintenance flush symbol-cache
235 maintenance flush register-cache
236 These new commands are equivalent to the already existing commands
237 'maintenance flush-symbol-cache' and 'flushregs' respectively.
239 maintenance flush dcache
240 A new command to flush the dcache.
242 maintenance info target-sections
243 Print GDB's internal target sections table.
246 Print the JIT code objects in the inferior known to GDB.
248 memory-tag show-logical-tag POINTER
249 Print the logical tag for POINTER.
250 memory-tag with-logical-tag POINTER TAG
251 Print POINTER with logical tag TAG.
252 memory-tag show-allocation-tag ADDRESS
253 Print the allocation tag for ADDRESS.
254 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
255 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
256 memory-tag check POINTER
257 Validate that POINTER's logical tag matches the allocation tag.
259 set startup-quietly on|off
261 When 'on', this causes GDB to act as if "-silent" were passed on the
262 command line. This command needs to be added to an early
263 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
266 set print type hex on|off
268 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
269 and offsets of struct members. When 'off', decimal notation is used.
271 set python ignore-environment on|off
272 show python ignore-environment
273 When 'on', this causes GDB's builtin Python to ignore any
274 environment variables that would otherwise affect how Python
275 behaves. This command needs to be added to an early initialization
276 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
278 set python dont-write-bytecode auto|on|off
279 show python dont-write-bytecode
280 When 'on', this causes GDB's builtin Python to not write any
281 byte-code (.pyc files) to disk. This command needs to be added to
282 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
283 order to affect GDB. When 'off' byte-code will always be written.
284 When set to 'auto' (the default) Python will check the
285 PYTHONDONTWRITEBYTECODE environment variable.
289 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
290 [-force-condition] [if CONDITION]
291 This command would previously refuse setting a breakpoint if the
292 CONDITION expression is invalid at a location. It now accepts and
293 defines the breakpoint if there is at least one location at which
294 the CONDITION is valid. The locations for which the CONDITION is
295 invalid, are automatically disabled. If CONDITION is invalid at all
296 of the locations, setting the breakpoint is still rejected. However,
297 the '-force-condition' flag can be used in this case for forcing GDB to
298 define the breakpoint, making all the current locations automatically
299 disabled. This may be useful if the user knows the condition will
300 become meaningful at a future location, e.g. due to a shared library
303 condition [-force] N COND
304 The behavior of this command is changed the same way for the 'break'
305 command as explained above. The '-force' flag can be used to force
306 GDB into defining the condition even when COND is invalid for all the
307 current locations of breakpoint N.
310 maintenance flush-symbol-cache
311 These commands are deprecated in favor of the new commands
312 'maintenance flush register-cache' and 'maintenance flush
313 symbol-cache' respectively.
315 set style version foreground COLOR
316 set style version background COLOR
317 set style version intensity VALUE
318 Control the styling of GDB's version number text.
321 When the ID parameter is omitted, then this command prints information
322 about the current inferior. When the ID parameter is present, the
323 behavior of the command is unchanged and have the inferior ID become
324 the current inferior.
326 maintenance info sections
327 The ALLOBJ keyword has been replaced with an -all-objects command
328 line flag. It is now possible to filter which sections are printed
329 even when -all-objects is passed.
331 ptype[/FLAGS] TYPE | EXPRESSION
332 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
333 notation is used when printing sizes and offsets of struct members.
334 When '/d' is set, decimal notation is used when printing sizes and
335 offsets of struct members. Default behavior is given by 'show print
339 The info sources command output has been restructured. The results
340 are now based around a list of objfiles (executable and libraries),
341 and for each objfile the source files that are part of that objfile
344 * Removed targets and native configurations
346 ARM Symbian arm*-*-symbianelf*
351 Request the remote to send allocation tags for a particular memory range.
353 Request the remote to store the specified allocation tags to the requested
358 ** Improved support for rvalue reference values:
359 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
360 value-referenced-value procedure now handles rvalue reference
363 ** New procedures for obtaining value variants:
364 value-reference-value, value-rvalue-reference-value and
367 ** Temporary breakpoints can now be created with make-breakpoint and
368 tested for using breakpoint-temporary?.
372 ** Inferior objects now contain a read-only 'connection_num' attribute that
373 gives the connection number as seen in 'info connections' and
376 ** New method gdb.Frame.level() which returns the stack level of the
379 ** New method gdb.PendingFrame.level() which returns the stack level
382 ** When hitting a catchpoint, the Python API will now emit a
383 gdb.BreakpointEvent rather than a gdb.StopEvent. The
384 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
386 ** Python TUI windows can now receive mouse click events. If the
387 Window object implements the click method, it is called for each
388 mouse click event in this window.
390 *** Changes in GDB 10
392 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
393 and "org.gnu.gdb.arc.aux". The old names are still supported but
394 must be considered obsolete. They will be deprecated after some
397 * Help and apropos commands will now show the documentation of a
398 command only once, even if that command has one or more aliases.
399 These commands now show the command name, then all of its aliases,
400 and finally the description of the command.
402 * 'help aliases' now shows only the user defined aliases. GDB predefined
403 aliases are shown together with their aliased command.
405 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
406 debugging information as well as source code.
408 When built with debuginfod, GDB can automatically query debuginfod
409 servers for the separate debug files and source code of the executable
412 To build GDB with debuginfod, pass --with-debuginfod to configure (this
413 requires libdebuginfod, the debuginfod client library).
415 debuginfod is distributed with elfutils, starting with version 0.178.
417 You can get the latest version from https://sourceware.org/elfutils.
419 * Multi-target debugging support
421 GDB now supports debugging multiple target connections
422 simultaneously. For example, you can now have each inferior
423 connected to different remote servers running in different machines,
424 or have one inferior debugging a local native process, an inferior
425 debugging a core dump, etc.
427 This support is experimental and comes with some limitations -- you
428 can only resume multiple targets simultaneously if all targets
429 support non-stop mode, and all remote stubs or servers must support
430 the same set of remote protocol features exactly. See also "info
431 connections" and "add-inferior -no-connection" below, and "maint set
432 target-non-stop" in the user manual.
434 * New features in the GDB remote stub, GDBserver
436 ** GDBserver is now supported on ARC GNU/Linux.
438 ** GDBserver is now supported on RISC-V GNU/Linux.
440 ** GDBserver no longer supports these host triplets:
451 i[34567]86-*-mingw32ce*
453 * Debugging MS-Windows processes now sets $_exitsignal when the
454 inferior is terminated by a signal, instead of setting $_exitcode.
456 * Multithreaded symbol loading has now been enabled by default on systems
457 that support it (see entry for GDB 9, below), providing faster
458 performance for programs with many symbols.
460 * The $_siginfo convenience variable now also works on Windows targets,
461 and will display the EXCEPTION_RECORD of the last handled exception.
463 * TUI windows can now be arranged horizontally.
465 * The command history filename can now be set to the empty string
466 either using 'set history filename' or by setting 'GDBHISTFILE=' in
467 the environment. The effect of setting this filename to the empty
468 string is that GDB will not try to load any previous command
471 * On Windows targets, it is now possible to debug 32-bit programs with a
476 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
477 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
478 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
479 running process, this new option indicates whether to detect
480 a mismatch between the current executable file loaded by GDB and the
481 executable file used to start the process. If 'ask', the default,
482 display a warning and ask the user whether to load the process
483 executable file; if 'warn', just display a warning; if 'off', don't
484 attempt to detect a mismatch.
486 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
487 Define a new TUI layout, specifying its name and the windows that
490 maintenance print xml-tdesc [FILE]
491 Prints the current target description as an XML document. If the
492 optional FILE is provided (which is an XML target description) then
493 the target description is read from FILE into GDB, and then
496 maintenance print core-file-backed-mappings
497 Prints file-backed mappings loaded from a core file's note section.
498 Output is expected to be similar to that of "info proc mappings".
500 set debug fortran-array-slicing on|off
501 show debug fortran-array-slicing
502 Print debugging when taking slices of Fortran arrays.
504 set fortran repack-array-slices on|off
505 show fortran repack-array-slices
506 When taking slices from Fortran arrays and strings, if the slice is
507 non-contiguous within the original value then, when this option is
508 on, the new value will be repacked into a single contiguous value.
509 When this option is off, then the value returned will consist of a
510 descriptor that describes the slice within the memory of the
511 original parent value.
515 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
516 The alias command can now specify default args for an alias.
517 GDB automatically prepends the alias default args to the argument list
518 provided explicitly by the user.
519 For example, to have a backtrace with full details, you can define
521 'alias bt_ALL = backtrace -entry-values both -frame-arg all
522 -past-main -past-entry -full'.
523 Alias default arguments can also use a set of nested 'with' commands,
524 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
525 defines the alias pp10 that will pretty print a maximum of 10 elements
526 of the given expression (if the expression is an array).
530 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
536 ** gdb.register_window_type can be used to implement new TUI windows
539 ** Dynamic types can now be queried. gdb.Type has a new attribute,
540 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
541 field of a dynamic type may have None for its "bitpos" attribute
544 ** Commands written in Python can be in the "TUI" help class by
545 registering with the new constant gdb.COMMAND_TUI.
547 ** New method gdb.PendingFrame.architecture () to retrieve the
548 architecture of the pending frame.
550 ** New gdb.Architecture.registers method that returns a
551 gdb.RegisterDescriptorIterator object, an iterator that returns
552 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
553 way to query the registers available for an architecture.
555 ** New gdb.Architecture.register_groups method that returns a
556 gdb.RegisterGroupIterator object, an iterator that returns
557 gdb.RegisterGroup objects. The new RegisterGroup is a way to
558 discover the available register groups.
562 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
564 ** Procedures 'memory-port-read-buffer-size',
565 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
566 and 'set-memory-port-write-buffer-size!' are deprecated. When
567 using Guile 2.2 and later, users who need to control the size of
568 a memory port's internal buffer can use the 'setvbuf' procedure.
572 * 'thread-exited' event is now available in the annotations interface.
574 * New built-in convenience variables $_gdb_major and $_gdb_minor
575 provide the GDB version. They are handy for conditionally using
576 features available only in or since specific GDB versions, in
577 scripts that should work error-free with many different versions,
578 such as in system-wide init files.
580 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
581 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
582 of the GDB settings and the GDB maintenance settings. They are handy
583 for changing the logic of user defined commands depending on the
584 current GDB settings.
586 * GDB now supports Thread Local Storage (TLS) variables on several
587 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
588 architectures require kernel changes. TLS is not yet supported for
589 amd64 and i386 process core dumps.
591 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
592 addresses that required unmasking are shown in the backtrace with the
595 * Two new convenience functions $_cimag and $_creal that extract the
596 imaginary and real parts respectively from complex numbers.
598 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
599 provide the exitcode or exit status of the shell commands launched by
600 GDB commands such as "shell", "pipe" and "make".
602 * The command define-prefix can now define user defined prefix commands.
603 User defined commands can now be defined using these user defined prefix
606 * Command names can now use the . character.
608 * The RX port now supports XML target descriptions.
610 * GDB now shows the Ada task names at more places, e.g. in task switching
613 * GDB can now be compiled with Python 3 on Windows.
615 * New convenience variable $_ada_exception holds the address of the
616 Ada exception being thrown. This is set by Ada-related catchpoints.
618 * GDB can now place breakpoints on nested functions and subroutines in
619 Fortran code. The '::' operator can be used between parent and
620 child scopes when placing breakpoints, for example:
622 (gdb) break outer_function::inner_function
624 The 'outer_function::' prefix is only needed if 'inner_function' is
625 not visible in the current scope.
627 * In addition to the system-wide gdbinit file, if configured with
628 --with-system-gdbinit-dir, GDB will now also load files in that directory
629 as system gdbinit files, unless the -nx or -n flag is provided. Files
630 with extensions .gdb, .py and .scm are supported as long as GDB was
631 compiled with support for that language.
633 * GDB now supports multithreaded symbol loading for higher performance.
634 This feature is still in testing, so it is disabled by default. You
635 can turn it on using 'maint set worker-threads unlimited'.
639 ** The gdb.Value type has a new method 'format_string' which returns a
640 string representing the value. The formatting is controlled by the
641 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
642 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
643 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
645 ** gdb.Type has a new property 'objfile' which returns the objfile the
648 ** The frame information printed by the python frame filtering code
649 is now consistent with what the 'backtrace' command prints when
650 there are no filters, or when the 'backtrace' '-no-filters' option
653 ** The new function gdb.lookup_static_symbol can be used to look up
654 symbols with static linkage.
656 ** The new function gdb.lookup_static_symbols can be used to look up
657 all static symbols with static linkage.
659 ** gdb.Objfile has new methods 'lookup_global_symbol' and
660 'lookup_static_symbol' to lookup a symbol from this objfile only.
662 ** gdb.Block now supports the dictionary syntax for accessing symbols in
663 this block (e.g. block['local_variable']).
667 | [COMMAND] | SHELL_COMMAND
668 | -d DELIM COMMAND DELIM SHELL_COMMAND
669 pipe [COMMAND] | SHELL_COMMAND
670 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
671 Executes COMMAND and sends its output to SHELL_COMMAND.
672 With no COMMAND, repeat the last executed command
673 and send its output to SHELL_COMMAND.
675 define-prefix COMMAND
676 Define or mark a command as a user-defined prefix command.
678 with SETTING [VALUE] [-- COMMAND]
679 w SETTING [VALUE] [-- COMMAND]
680 Temporarily set SETTING, run COMMAND, and restore SETTING.
681 Usage: with SETTING -- COMMAND
682 With no COMMAND, repeats the last executed command.
683 SETTING is any GDB setting you can change with the "set"
684 subcommands. For example, 'with language c -- print someobj'
685 temporarily switches to the C language in order to print someobj.
686 Settings can be combined: 'w lang c -- w print elements unlimited --
687 usercmd' switches to the C language and runs usercmd with no limit
688 of array elements to print.
690 maint with SETTING [VALUE] [-- COMMAND]
691 Like "with", but works with "maintenance set" settings.
693 set may-call-functions [on|off]
694 show may-call-functions
695 This controls whether GDB will attempt to call functions in
696 the program, such as with expressions in the print command. It
697 defaults to on. Calling functions in the program being debugged
698 can have undesired side effects. It is now possible to forbid
699 such function calls. If function calls are forbidden, GDB will throw
700 an error when a command (such as print expression) calls a function
703 set print finish [on|off]
705 This controls whether the `finish' command will display the value
706 that is returned by the current function. When `off', the value is
707 still entered into the value history, but it is not printed. The
712 Allows deeply nested structures to be simplified when printing by
713 replacing deeply nested parts (beyond the max-depth) with ellipses.
714 The default max-depth is 20, but this can be set to unlimited to get
715 the old behavior back.
717 set print raw-values [on|off]
718 show print raw-values
719 By default, GDB applies the enabled pretty printers when printing a
720 value. This allows to ignore the enabled pretty printers for a series
721 of commands. The default is 'off'.
723 set logging debugredirect [on|off]
724 By default, GDB debug output will go to both the terminal and the logfile.
725 Set if you want debug output to go only to the log file.
727 set style title foreground COLOR
728 set style title background COLOR
729 set style title intensity VALUE
730 Control the styling of titles.
732 set style highlight foreground COLOR
733 set style highlight background COLOR
734 set style highlight intensity VALUE
735 Control the styling of highlightings.
737 maint set worker-threads
738 maint show worker-threads
739 Control the number of worker threads that can be used by GDB. The
740 default is 0. "unlimited" lets GDB choose a number that is
741 reasonable. Currently worker threads are only used when demangling
742 the names of linker symbols.
744 set style tui-border foreground COLOR
745 set style tui-border background COLOR
746 Control the styling of TUI borders.
748 set style tui-active-border foreground COLOR
749 set style tui-active-border background COLOR
750 Control the styling of the active TUI border.
752 maint set test-settings KIND
753 maint show test-settings KIND
754 A set of commands used by the testsuite for exercising the settings
757 maint set tui-resize-message [on|off]
758 maint show tui-resize-message
759 Control whether GDB prints a message each time the terminal is
760 resized when in TUI mode. This is primarily useful for testing the
763 set print frame-info [short-location|location|location-and-address
764 |source-and-location|source-line|auto]
765 show print frame-info
766 This controls what frame information is printed by the commands printing
767 a frame. This setting will e.g. influence the behaviour of 'backtrace',
768 'frame', 'stepi'. The python frame filtering also respect this setting.
769 The 'backtrace' '-frame-info' option can override this global setting.
771 set tui compact-source
772 show tui compact-source
774 Enable the "compact" display mode for the TUI source window. The
775 compact display uses only as much space as is needed for the line
776 numbers in the current file, and only a single space to separate the
777 line numbers from the source.
779 info modules [-q] [REGEXP]
780 Return a list of Fortran modules matching REGEXP, or all modules if
783 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
784 Return a list of functions within all modules, grouped by module.
785 The list of functions can be restricted with the optional regular
786 expressions. MODULE_REGEXP matches against the module name,
787 TYPE_REGEXP matches against the function type signature, and REGEXP
788 matches against the function name.
790 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
791 Return a list of variables within all modules, grouped by module.
792 The list of variables can be restricted with the optional regular
793 expressions. MODULE_REGEXP matches against the module name,
794 TYPE_REGEXP matches against the variable type, and REGEXP matches
795 against the variable name.
797 set debug remote-packet-max-chars
798 show debug remote-packet-max-chars
799 Controls the number of characters to output in a remote packet when using
801 The default is 512 bytes.
804 Lists the target connections currently in use.
809 The "help" command uses the title style to enhance the
810 readibility of its output by styling the classes and
814 Similarly to "help", the "apropos" command also uses the
815 title style for the command names. "apropos" accepts now
816 a flag "-v" (verbose) to show the full documentation
817 of matching commands and to use the highlight style to mark
818 the documentation parts matching REGEXP.
822 The GDB printf and eval commands can now print C-style and Ada-style
823 string convenience variables without calling functions in the program.
824 This allows to do formatted printing of strings without having
825 a running inferior, or when debugging a core dump.
827 info sources [-dirname | -basename] [--] [REGEXP]
828 This command has now optional arguments to only print the files
829 whose names match REGEXP. The arguments -dirname and -basename
830 allow to restrict matching respectively to the dirname and basename
834 The "show style" and its subcommands are now styling
835 a style name in their output using its own style, to help
836 the user visualize the different styles.
838 set print frame-arguments
839 The new value 'presence' indicates to only indicate the presence of
840 arguments using ..., instead of printing argument names and values.
842 set print raw-frame-arguments
843 show print raw-frame-arguments
845 These commands replace the similarly-named "set/show print raw
846 frame-arguments" commands (now with a dash instead of a space). The
847 old commands are now deprecated and may be removed in a future
850 add-inferior [-no-connection]
851 The add-inferior command now supports a "-no-connection" flag that
852 makes the new inferior start with no target connection associated.
853 By default, the new inferior inherits the target connection of the
854 current inferior. See also "info connections".
857 This command's output now includes a new "Connection" column
858 indicating which target connection an inferior is bound to. See
859 "info connections" above.
861 maint test-options require-delimiter
862 maint test-options unknown-is-error
863 maint test-options unknown-is-operand
864 maint show test-options-completion-result
865 Commands used by the testsuite to validate the command options
868 focus, winheight, +, -, >, <
869 These commands are now case-sensitive.
871 * New command options, command completion
873 GDB now has a standard infrastructure to support dash-style command
874 options ('-OPT'). One benefit is that commands that use it can
875 easily support completion of command line arguments. Try "CMD
876 -[TAB]" or "help CMD" to find options supported by a command. Over
877 time, we intend to migrate most commands to this infrastructure. A
878 number of commands got support for new command options in this
881 ** The "print" and "compile print" commands now support a number of
882 options that allow overriding relevant global print settings as
883 set by "set print" subcommands:
887 -array-indexes [on|off]
888 -elements NUMBER|unlimited
893 -repeats NUMBER|unlimited
894 -static-members [on|off]
899 Note that because the "print"/"compile print" commands accept
900 arbitrary expressions which may look like options (including
901 abbreviations), if you specify any command option, then you must
902 use a double dash ("--") to mark the end of argument processing.
904 ** The "backtrace" command now supports a number of options that
905 allow overriding relevant global print settings as set by "set
906 backtrace" and "set print" subcommands:
908 -entry-values no|only|preferred|if-needed|both|compact|default
909 -frame-arguments all|scalars|none
910 -raw-frame-arguments [on|off]
911 -frame-info auto|source-line|location|source-and-location
912 |location-and-address|short-location
916 In addition, the full/no-filters/hide qualifiers are now also
917 exposed as command options too:
923 ** The "frame apply", "tfaas" and "faas" commands similarly now
924 support the following options:
929 ** The new "info sources" options -dirname and -basename options
930 are using the standard '-OPT' infrastructure.
932 All options above can also be abbreviated. The argument of boolean
933 (on/off) options can be 0/1 too, and also the argument is assumed
934 "on" if omitted. This allows writing compact command invocations,
937 (gdb) p -ra -p -o 0 -- *myptr
939 The above is equivalent to:
941 (gdb) print -raw-values -pretty -object off -- *myptr
943 ** The "info types" command now supports the '-q' flag to disable
944 printing of some header information in a similar fashion to "info
945 variables" and "info functions".
947 ** The "info variables", "info functions", and "whereis" commands
948 now take a '-n' flag that excludes non-debug symbols (symbols
949 from the symbol table, not from the debug info such as DWARF)
952 * Completion improvements
954 ** GDB can now complete the options of the "thread apply all" and
955 "taas" commands, and their "-ascending" option can now be
958 ** GDB can now complete the options of the "info threads", "info
959 functions", "info variables", "info locals", and "info args"
962 ** GDB can now complete the options of the "compile file" and
963 "compile code" commands. The "compile file" command now
964 completes on filenames.
966 ** GDB can now complete the backtrace command's
967 "full/no-filters/hide" qualifiers.
969 * In settings, you can now abbreviate "unlimited".
971 E.g., "set print elements u" is now equivalent to "set print
977 This lists all the possible completions for the rest of the line, if it
978 were to be given as a command itself. This is intended for use by MI
979 frontends in cases when separate CLI and MI channels cannot be used.
981 -catch-throw, -catch-rethrow, and -catch-catch
982 These can be used to catch C++ exceptions in a similar fashion to
983 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
985 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
986 These commands are the MI equivalent of the CLI commands 'info
987 functions', 'info types', and 'info variables' respectively.
989 -symbol-info-modules, this is the MI equivalent of the CLI 'info
992 -symbol-info-module-functions and -symbol-info-module-variables.
993 These commands are the MI equivalent of the CLI commands 'info
994 module functions' and 'info module variables'.
998 ** The default version of the MI interpreter is now 3 (-i=mi3).
1000 ** The output of information about multi-location breakpoints (which is
1001 syntactically incorrect in MI 2) has changed in MI 3. This affects
1002 the following commands and events:
1006 - =breakpoint-created
1007 - =breakpoint-modified
1009 The -fix-multi-location-breakpoint-output command can be used to enable
1010 this behavior with previous MI versions.
1012 ** Backtraces and frames include a new optional field addr_flags which is
1013 given after the addr field. On AArch64 this contains PAC if the address
1014 has been masked in the frame. On all other targets the field is not
1019 The testsuite now creates the files gdb.cmd (containing the arguments
1020 used to launch GDB) and gdb.in (containing all the commands sent to
1021 GDB) in the output directory for each test script. Multiple invocations
1022 are appended with .1, .2, .3 etc.
1024 * Building GDB and GDBserver now requires GNU make >= 3.82.
1026 Using another implementation of the make program or an earlier version of
1027 GNU make to build GDB or GDBserver is not supported.
1029 * Building GDB now requires GNU readline >= 7.0.
1031 GDB now bundles GNU readline 8.0, but if you choose to use
1032 --with-system-readline, only readline >= 7.0 can be used.
1034 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1035 from .inputrc to bind keys in this keymap. This feature is only
1036 available when gdb is built against GNU readline 8.0 or later.
1038 * Removed targets and native configurations
1040 GDB no longer supports debugging the Cell Broadband Engine. This includes
1041 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1042 of Cell/B.E. applications that use both the PPU and SPU architectures.
1048 * Removed targets and native configurations
1050 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1051 sparc*-*-solaris2.10
1053 *** Changes in GDB 8.3
1055 * GDB and GDBserver now support access to additional registers on
1056 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1059 * GDB now has experimental support for the compilation and injection of
1060 C++ source code into the inferior. This beta release does not include
1061 support for several language features, such as templates, constructors,
1064 This feature requires GCC 7.1 or higher built with libcp1.so
1067 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1068 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1069 'ADDRESS:PORT' method.
1071 * DWARF index cache: GDB can now automatically save indices of DWARF
1072 symbols on disk to speed up further loading of the same binaries.
1074 * Ada task switching is now supported on aarch64-elf targets when
1075 debugging a program using the Ravenscar Profile. For more information,
1076 see the "Tasking Support when using the Ravenscar Profile" section
1077 in the GDB user manual.
1079 * GDB in batch mode now exits with status 1 if the last command to be
1082 * The RISC-V target now supports target descriptions.
1084 * System call catchpoints now support system call aliases on FreeBSD.
1085 When the ABI of a system call changes in FreeBSD, this is
1086 implemented by leaving a compatibility system call using the old ABI
1087 at the existing number and allocating a new system call number for
1088 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1089 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1090 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1091 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1092 so that a system call catchpoint for the 'kevent' system call will
1093 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1094 binaries. This ensures that 'kevent' system calls are caught for
1095 binaries using either the old or new ABIs.
1097 * Terminal styling is now available for the CLI and the TUI. GNU
1098 Source Highlight can additionally be used to provide styling of
1099 source code snippets. See the "set style" commands, below, for more
1102 * Removed support for old demangling styles arm, edg, gnu, hp and
1107 set debug compile-cplus-types
1108 show debug compile-cplus-types
1109 Control the display of debug output about type conversion in the
1110 C++ compile feature. Commands have no effect while compiling
1111 for other languages.
1115 Control whether debug output about files/functions skipping is
1118 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1119 Apply a command to some frames.
1120 FLAG arguments allow to control what output to produce and how to handle
1121 errors raised when applying COMMAND to a frame.
1124 Apply a command to all threads (ignoring errors and empty output).
1125 Shortcut for 'thread apply all -s COMMAND'.
1128 Apply a command to all frames (ignoring errors and empty output).
1129 Shortcut for 'frame apply all -s COMMAND'.
1132 Apply a command to all frames of all threads (ignoring errors and empty
1134 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1136 maint set dwarf unwinders (on|off)
1137 maint show dwarf unwinders
1138 Control whether DWARF unwinders can be used.
1141 Display a list of open files for a process.
1145 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1146 These commands all now take a frame specification which
1147 is either a frame level, or one of the keywords 'level', 'address',
1148 'function', or 'view' followed by a parameter. Selecting a frame by
1149 address, or viewing a frame outside the current backtrace now
1150 requires the use of a keyword. Selecting a frame by level is
1151 unchanged. The MI comment "-stack-select-frame" is unchanged.
1153 target remote FILENAME
1154 target extended-remote FILENAME
1155 If FILENAME is a Unix domain socket, GDB will attempt to connect
1156 to this socket instead of opening FILENAME as a character device.
1158 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1159 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1160 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1161 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1162 These commands can now print only the searched entities
1163 matching the provided regexp(s), giving a condition
1164 on the entity names or entity types. The flag -q disables
1165 printing headers or informations messages.
1171 These commands now determine the syntax for the shown entities
1172 according to the language chosen by `set language'. In particular,
1173 `set language auto' means to automatically choose the language of
1176 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1177 The 'thread apply' command accepts new FLAG arguments.
1178 FLAG arguments allow to control what output to produce and how to handle
1179 errors raised when applying COMMAND to a thread.
1181 set tui tab-width NCHARS
1182 show tui tab-width NCHARS
1183 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1185 set style enabled [on|off]
1187 Enable or disable terminal styling. Styling is enabled by default
1188 on most hosts, but disabled by default when in batch mode.
1190 set style sources [on|off]
1192 Enable or disable source code styling. Source code styling is
1193 enabled by default, but only takes effect if styling in general is
1194 enabled, and if GDB was linked with GNU Source Highlight.
1196 set style filename foreground COLOR
1197 set style filename background COLOR
1198 set style filename intensity VALUE
1199 Control the styling of file names.
1201 set style function foreground COLOR
1202 set style function background COLOR
1203 set style function intensity VALUE
1204 Control the styling of function names.
1206 set style variable foreground COLOR
1207 set style variable background COLOR
1208 set style variable intensity VALUE
1209 Control the styling of variable names.
1211 set style address foreground COLOR
1212 set style address background COLOR
1213 set style address intensity VALUE
1214 Control the styling of addresses.
1218 ** The '-data-disassemble' MI command now accepts an '-a' option to
1219 disassemble the whole function surrounding the given program
1220 counter value or function name. Support for this feature can be
1221 verified by using the "-list-features" command, which should
1222 contain "data-disassemble-a-option".
1224 ** Command responses and notifications that include a frame now include
1225 the frame's architecture in a new "arch" attribute.
1227 * New native configurations
1229 GNU/Linux/RISC-V riscv*-*-linux*
1230 FreeBSD/riscv riscv*-*-freebsd*
1234 GNU/Linux/RISC-V riscv*-*-linux*
1235 CSKY ELF csky*-*-elf
1236 CSKY GNU/LINUX csky*-*-linux
1237 FreeBSD/riscv riscv*-*-freebsd*
1239 GNU/Linux/OpenRISC or1k*-*-linux*
1243 GDB no longer supports native debugging on versions of MS-Windows
1248 ** GDB no longer supports Python versions less than 2.6.
1250 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1251 space associated to that inferior.
1253 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1254 of objfiles associated to that program space.
1256 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1257 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1260 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1261 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1262 correct and did not work properly.
1264 ** The gdb.Value type has a new constructor, which is used to construct a
1265 gdb.Value from a Python buffer object and a gdb.Type.
1271 Enable or disable the undefined behavior sanitizer. This is
1272 disabled by default, but passing --enable-ubsan=yes or
1273 --enable-ubsan=auto to configure will enable it. Enabling this can
1274 cause a performance penalty. The undefined behavior sanitizer was
1275 first introduced in GCC 4.9.
1277 *** Changes in GDB 8.2
1279 * The 'set disassembler-options' command now supports specifying options
1280 for the MIPS target.
1282 * The 'symbol-file' command now accepts an '-o' option to add a relative
1283 offset to all sections.
1285 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1286 a relative offset to all sections, but it allows to override the load
1287 address of individual sections using '-s'.
1289 * The 'add-symbol-file' command no longer requires the second argument
1290 (address of the text section).
1292 * The endianness used with the 'set endian auto' mode in the absence of
1293 an executable selected for debugging is now the last endianness chosen
1294 either by one of the 'set endian big' and 'set endian little' commands
1295 or by inferring from the last executable used, rather than the startup
1298 * The pager now allows a "c" response, meaning to disable the pager
1299 for the rest of the current command.
1301 * The commands 'info variables/functions/types' now show the source line
1302 numbers of symbol definitions when available.
1304 * 'info proc' now works on running processes on FreeBSD systems and core
1305 files created on FreeBSD systems.
1307 * C expressions can now use _Alignof, and C++ expressions can now use
1310 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1311 the vector length while the process is running.
1317 Control display of debugging info regarding the FreeBSD native target.
1319 set|show varsize-limit
1320 This new setting allows the user to control the maximum size of Ada
1321 objects being printed when those objects have a variable type,
1322 instead of that maximum size being hardcoded to 65536 bytes.
1324 set|show record btrace cpu
1325 Controls the processor to be used for enabling errata workarounds for
1326 branch trace decode.
1328 maint check libthread-db
1329 Run integrity checks on the current inferior's thread debugging
1332 maint set check-libthread-db (on|off)
1333 maint show check-libthread-db
1334 Control whether to run integrity checks on inferior specific thread
1335 debugging libraries as they are loaded. The default is not to
1336 perform such checks.
1340 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1342 ** The commands attached to a breakpoint can be set by assigning to
1343 the breakpoint's "commands" field.
1345 ** gdb.execute can now execute multi-line gdb commands.
1347 ** The new functions gdb.convenience_variable and
1348 gdb.set_convenience_variable can be used to get and set the value
1349 of convenience variables.
1351 ** A gdb.Parameter will no longer print the "set" help text on an
1352 ordinary "set"; instead by default a "set" will be silent unless
1353 the get_set_string method returns a non-empty string.
1357 RiscV ELF riscv*-*-elf
1359 * Removed targets and native configurations
1361 m88k running OpenBSD m88*-*-openbsd*
1362 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1363 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1364 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1366 * Aarch64/Linux hardware watchpoints improvements
1368 Hardware watchpoints on unaligned addresses are now properly
1369 supported when running Linux kernel 4.10 or higher: read and access
1370 watchpoints are no longer spuriously missed, and all watchpoints
1371 lengths between 1 and 8 bytes are supported. On older kernels,
1372 watchpoints set on unaligned addresses are no longer missed, with
1373 the tradeoff that there is a possibility of false hits being
1378 --enable-codesign=CERT
1379 This can be used to invoke "codesign -s CERT" after building gdb.
1380 This option is useful on macOS, where code signing is required for
1381 gdb to work properly.
1383 --disable-gdbcli has been removed
1384 This is now silently accepted, but does nothing.
1386 *** Changes in GDB 8.1
1388 * GDB now supports dynamically creating arbitrary register groups specified
1389 in XML target descriptions. This allows for finer grain grouping of
1390 registers on systems with a large amount of registers.
1392 * The 'ptype' command now accepts a '/o' flag, which prints the
1393 offsets and sizes of fields in a struct, like the pahole(1) tool.
1395 * New "--readnever" command line option instructs GDB to not read each
1396 symbol file's symbolic debug information. This makes startup faster
1397 but at the expense of not being able to perform symbolic debugging.
1398 This option is intended for use cases where symbolic debugging will
1399 not be used, e.g., when you only need to dump the debuggee's core.
1401 * GDB now uses the GNU MPFR library, if available, to emulate target
1402 floating-point arithmetic during expression evaluation when the target
1403 uses different floating-point formats than the host. At least version
1404 3.1 of GNU MPFR is required.
1406 * GDB now supports access to the guarded-storage-control registers and the
1407 software-based guarded-storage broadcast control registers on IBM z14.
1409 * On Unix systems, GDB now supports transmitting environment variables
1410 that are to be set or unset to GDBserver. These variables will
1411 affect the environment to be passed to the remote inferior.
1413 To inform GDB of environment variables that are to be transmitted to
1414 GDBserver, use the "set environment" command. Only user set
1415 environment variables are sent to GDBserver.
1417 To inform GDB of environment variables that are to be unset before
1418 the remote inferior is started by the GDBserver, use the "unset
1419 environment" command.
1421 * Completion improvements
1423 ** GDB can now complete function parameters in linespecs and
1424 explicit locations without quoting. When setting breakpoints,
1425 quoting around functions names to help with TAB-completion is
1426 generally no longer necessary. For example, this now completes
1429 (gdb) b function(in[TAB]
1430 (gdb) b function(int)
1432 Related, GDB is no longer confused with completing functions in
1433 C++ anonymous namespaces:
1436 (gdb) b (anonymous namespace)::[TAB][TAB]
1437 (anonymous namespace)::a_function()
1438 (anonymous namespace)::b_function()
1440 ** GDB now has much improved linespec and explicit locations TAB
1441 completion support, that better understands what you're
1442 completing and offers better suggestions. For example, GDB no
1443 longer offers data symbols as possible completions when you're
1444 setting a breakpoint.
1446 ** GDB now TAB-completes label symbol names.
1448 ** The "complete" command now mimics TAB completion accurately.
1450 * New command line options (gcore)
1453 Dump all memory mappings.
1455 * Breakpoints on C++ functions are now set on all scopes by default
1457 By default, breakpoints on functions/methods are now interpreted as
1458 specifying all functions with the given name ignoring missing
1459 leading scopes (namespaces and classes).
1461 For example, assuming a C++ program with symbols named:
1466 both commands "break func()" and "break B::func()" set a breakpoint
1469 You can use the new flag "-qualified" to override this. This makes
1470 GDB interpret the specified function name as a complete
1471 fully-qualified name instead. For example, using the same C++
1472 program, the "break -q B::func" command sets a breakpoint on
1473 "B::func", only. A parameter has been added to the Python
1474 gdb.Breakpoint constructor to achieve the same result when creating
1475 a breakpoint from Python.
1477 * Breakpoints on functions marked with C++ ABI tags
1479 GDB can now set breakpoints on functions marked with C++ ABI tags
1480 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1481 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1483 Functions with a C++11 abi tag are demangled/displayed like this:
1485 function[abi:cxx11](int)
1488 You can now set a breakpoint on such functions simply as if they had
1491 (gdb) b function(int)
1493 Or if you need to disambiguate between tags, like:
1495 (gdb) b function[abi:other_tag](int)
1497 Tab completion was adjusted accordingly as well.
1501 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1502 gdb.new_thread are emitted. See the manual for further
1503 description of these.
1505 ** A new function, "gdb.rbreak" has been added to the Python API.
1506 This function allows the setting of a large number of breakpoints
1507 via a regex pattern in Python. See the manual for further details.
1509 ** Python breakpoints can now accept explicit locations. See the
1510 manual for a further description of this feature.
1513 * New features in the GDB remote stub, GDBserver
1515 ** GDBserver is now able to start inferior processes with a
1516 specified initial working directory.
1518 The user can set the desired working directory to be used from
1519 GDB using the new "set cwd" command.
1521 ** New "--selftest" command line option runs some GDBserver self
1522 tests. These self tests are disabled in releases.
1524 ** On Unix systems, GDBserver now does globbing expansion and variable
1525 substitution in inferior command line arguments.
1527 This is done by starting inferiors using a shell, like GDB does.
1528 See "set startup-with-shell" in the user manual for how to disable
1529 this from GDB when using "target extended-remote". When using
1530 "target remote", you can disable the startup with shell by using the
1531 new "--no-startup-with-shell" GDBserver command line option.
1533 ** On Unix systems, GDBserver now supports receiving environment
1534 variables that are to be set or unset from GDB. These variables
1535 will affect the environment to be passed to the inferior.
1537 * When catching an Ada exception raised with a message, GDB now prints
1538 the message in the catchpoint hit notification. In GDB/MI mode, that
1539 information is provided as an extra field named "exception-message"
1540 in the *stopped notification.
1542 * Trait objects can now be inspected When debugging Rust code. This
1543 requires compiler support which will appear in Rust 1.24.
1545 * New remote packets
1547 QEnvironmentHexEncoded
1548 Inform GDBserver of an environment variable that is to be passed to
1549 the inferior when starting it.
1552 Inform GDBserver of an environment variable that is to be unset
1553 before starting the remote inferior.
1556 Inform GDBserver that the environment should be reset (i.e.,
1557 user-set environment variables should be unset).
1560 Indicates whether the inferior must be started with a shell or not.
1563 Tell GDBserver that the inferior to be started should use a specific
1566 * The "maintenance print c-tdesc" command now takes an optional
1567 argument which is the file name of XML target description.
1569 * The "maintenance selftest" command now takes an optional argument to
1570 filter the tests to be run.
1572 * The "enable", and "disable" commands now accept a range of
1573 breakpoint locations, e.g. "enable 1.3-5".
1578 Set and show the current working directory for the inferior.
1580 set|show compile-gcc
1581 Set and show compilation command used for compiling and injecting code
1582 with the 'compile' commands.
1584 set debug separate-debug-file
1585 show debug separate-debug-file
1586 Control the display of debug output about separate debug file search.
1588 set dump-excluded-mappings
1589 show dump-excluded-mappings
1590 Control whether mappings marked with the VM_DONTDUMP flag should be
1591 dumped when generating a core file.
1593 maint info selftests
1594 List the registered selftests.
1597 Start the debugged program stopping at the first instruction.
1600 Control display of debugging messages related to OpenRISC targets.
1602 set|show print type nested-type-limit
1603 Set and show the limit of nesting level for nested types that the
1604 type printer will show.
1606 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1609 * Safer/improved support for debugging with no debug info
1611 GDB no longer assumes functions with no debug information return
1614 This means that GDB now refuses to call such functions unless you
1615 tell it the function's type, by either casting the call to the
1616 declared return type, or by casting the function to a function
1617 pointer of the right type, and calling that:
1619 (gdb) p getenv ("PATH")
1620 'getenv' has unknown return type; cast the call to its declared return type
1621 (gdb) p (char *) getenv ("PATH")
1622 $1 = 0x7fffffffe "/usr/local/bin:/"...
1623 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1624 $2 = 0x7fffffffe "/usr/local/bin:/"...
1626 Similarly, GDB no longer assumes that global variables with no debug
1627 info have type 'int', and refuses to print the variable's value
1628 unless you tell it the variable's type:
1631 'var' has unknown type; cast it to its declared type
1635 * New native configurations
1637 FreeBSD/aarch64 aarch64*-*-freebsd*
1638 FreeBSD/arm arm*-*-freebsd*
1642 FreeBSD/aarch64 aarch64*-*-freebsd*
1643 FreeBSD/arm arm*-*-freebsd*
1644 OpenRISC ELF or1k*-*-elf
1646 * Removed targets and native configurations
1648 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1650 *** Changes in GDB 8.0
1652 * GDB now supports access to the PKU register on GNU/Linux. The register is
1653 added by the Memory Protection Keys for Userspace feature which will be
1654 available in future Intel CPUs.
1656 * GDB now supports C++11 rvalue references.
1660 ** New functions to start, stop and access a running btrace recording.
1661 ** Rvalue references are now supported in gdb.Type.
1663 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1666 * Building GDB and GDBserver now requires a C++11 compiler.
1668 For example, GCC 4.8 or later.
1670 It is no longer possible to build GDB or GDBserver with a C
1671 compiler. The --disable-build-with-cxx configure option has been
1674 * Building GDB and GDBserver now requires GNU make >= 3.81.
1676 It is no longer supported to build GDB or GDBserver with another
1677 implementation of the make program or an earlier version of GNU make.
1679 * Native debugging on MS-Windows supports command-line redirection
1681 Command-line arguments used for starting programs on MS-Windows can
1682 now include redirection symbols supported by native Windows shells,
1683 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1684 as "run", "start", and "set args", as well as the corresponding MI
1687 * Support for thread names on MS-Windows.
1689 GDB now catches and handles the special exception that programs
1690 running on MS-Windows use to assign names to threads in the
1693 * Support for Java programs compiled with gcj has been removed.
1695 * User commands now accept an unlimited number of arguments.
1696 Previously, only up to 10 was accepted.
1698 * The "eval" command now expands user-defined command arguments.
1700 This makes it easier to process a variable number of arguments:
1705 eval "print $arg%d", $i
1710 * Target descriptions can now describe registers for sparc32 and sparc64.
1712 * GDB now supports DWARF version 5 (debug information format).
1713 Its .debug_names index is not yet supported.
1715 * New native configurations
1717 FreeBSD/mips mips*-*-freebsd
1721 Synopsys ARC arc*-*-elf32
1722 FreeBSD/mips mips*-*-freebsd
1724 * Removed targets and native configurations
1726 Alpha running FreeBSD alpha*-*-freebsd*
1727 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1732 Erases all the flash memory regions reported by the target.
1734 maint print arc arc-instruction address
1735 Print internal disassembler information about instruction at a given address.
1739 set disassembler-options
1740 show disassembler-options
1741 Controls the passing of target specific information to the disassembler.
1742 If it is necessary to specify more than one disassembler option then
1743 multiple options can be placed together into a comma separated list.
1744 The default value is the empty string. Currently, the only supported
1745 targets are ARM, PowerPC and S/390.
1750 Erases all the flash memory regions reported by the target. This is
1751 equivalent to the CLI command flash-erase.
1753 -file-list-shared-libraries
1754 List the shared libraries in the program. This is
1755 equivalent to the CLI command "info shared".
1758 Catchpoints stopping the program when Ada exceptions are
1759 handled. This is equivalent to the CLI command "catch handlers".
1761 *** Changes in GDB 7.12
1763 * GDB and GDBserver now build with a C++ compiler by default.
1765 The --enable-build-with-cxx configure option is now enabled by
1766 default. One must now explicitly configure with
1767 --disable-build-with-cxx in order to build with a C compiler. This
1768 option will be removed in a future release.
1770 * GDBserver now supports recording btrace without maintaining an active
1773 * GDB now supports a negative repeat count in the 'x' command to examine
1774 memory backward from the given address. For example:
1777 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
1778 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
1779 (gdb) x/-5i 0x0000000000400580
1780 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
1781 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
1782 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
1783 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
1784 0x40057b <main(int, char**)+25>:
1785 callq 0x400536 <Func1(int, char const*)>
1787 * Fortran: Support structures with fields of dynamic types and
1788 arrays of dynamic types.
1790 * The symbol dumping maintenance commands have new syntax.
1791 maint print symbols [-pc address] [--] [filename]
1792 maint print symbols [-objfile objfile] [-source source] [--] [filename]
1793 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
1794 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
1795 maint print msymbols [-objfile objfile] [--] [filename]
1797 * GDB now supports multibit bitfields and enums in target register
1800 * New Python-based convenience function $_as_string(val), which returns
1801 the textual representation of a value. This function is especially
1802 useful to obtain the text label of an enum value.
1804 * Intel MPX bound violation handling.
1806 Segmentation faults caused by a Intel MPX boundary violation
1807 now display the kind of violation (upper or lower), the memory
1808 address accessed and the memory bounds, along with the usual
1809 signal received and code location.
1813 Program received signal SIGSEGV, Segmentation fault
1814 Upper bound violation while accessing address 0x7fffffffc3b3
1815 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
1816 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
1818 * Rust language support.
1819 GDB now supports debugging programs written in the Rust programming
1820 language. See https://www.rust-lang.org/ for more information about
1823 * Support for running interpreters on specified input/output devices
1825 GDB now supports a new mechanism that allows frontends to provide
1826 fully featured GDB console views, as a better alternative to
1827 building such views on top of the "-interpreter-exec console"
1828 command. See the new "new-ui" command below. With that command,
1829 frontends can now start GDB in the traditional command-line mode
1830 running in an embedded terminal emulator widget, and create a
1831 separate MI interpreter running on a specified i/o device. In this
1832 way, GDB handles line editing, history, tab completion, etc. in the
1833 console all by itself, and the GUI uses the separate MI interpreter
1834 for its own control and synchronization, invisible to the command
1837 * The "catch syscall" command catches groups of related syscalls.
1839 The "catch syscall" command now supports catching a group of related
1840 syscalls using the 'group:' or 'g:' prefix.
1845 skip -gfile file-glob-pattern
1846 skip -function function
1847 skip -rfunction regular-expression
1848 A generalized form of the skip command, with new support for
1849 glob-style file names and regular expressions for function names.
1850 Additionally, a file spec and a function spec may now be combined.
1852 maint info line-table REGEXP
1853 Display the contents of GDB's internal line table data structure.
1856 Run any GDB unit tests that were compiled in.
1859 Start a new user interface instance running INTERP as interpreter,
1860 using the TTY file for input/output.
1864 ** gdb.Breakpoint objects have a new attribute "pending", which
1865 indicates whether the breakpoint is pending.
1866 ** Three new breakpoint-related events have been added:
1867 gdb.breakpoint_created, gdb.breakpoint_modified, and
1868 gdb.breakpoint_deleted.
1870 signal-event EVENTID
1871 Signal ("set") the given MS-Windows event object. This is used in
1872 conjunction with the Windows JIT debugging (AeDebug) support, where
1873 the OS suspends a crashing process until a debugger can attach to
1874 it. Resuming the crashing process, in order to debug it, is done by
1875 signalling an event.
1877 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
1878 was added in GDBserver, including JIT compiling fast tracepoint's
1879 conditional expression bytecode into native code.
1881 * Support for various remote target protocols and ROM monitors has
1884 target m32rsdi Remote M32R debugging over SDI
1885 target mips MIPS remote debugging protocol
1886 target pmon PMON ROM monitor
1887 target ddb NEC's DDB variant of PMON for Vr4300
1888 target rockhopper NEC RockHopper variant of PMON
1889 target lsi LSI variant of PMO
1891 * Support for tracepoints and fast tracepoints on powerpc-linux,
1892 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
1893 including JIT compiling fast tracepoint's conditional expression
1894 bytecode into native code.
1896 * MI async record =record-started now includes the method and format used for
1897 recording. For example:
1899 =record-started,thread-group="i1",method="btrace",format="bts"
1901 * MI async record =thread-selected now includes the frame field. For example:
1903 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
1907 Andes NDS32 nds32*-*-elf
1909 *** Changes in GDB 7.11
1911 * GDB now supports debugging kernel-based threads on FreeBSD.
1913 * Per-inferior thread numbers
1915 Thread numbers are now per inferior instead of global. If you're
1916 debugging multiple inferiors, GDB displays thread IDs using a
1917 qualified INF_NUM.THR_NUM form. For example:
1921 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
1922 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
1923 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
1924 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
1926 As consequence, thread numbers as visible in the $_thread
1927 convenience variable and in Python's InferiorThread.num attribute
1928 are no longer unique between inferiors.
1930 GDB now maintains a second thread ID per thread, referred to as the
1931 global thread ID, which is the new equivalent of thread numbers in
1932 previous releases. See also $_gthread below.
1934 For backwards compatibility, MI's thread IDs always refer to global
1937 * Commands that accept thread IDs now accept the qualified
1938 INF_NUM.THR_NUM form as well. For example:
1941 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
1944 * In commands that accept a list of thread IDs, you can now refer to
1945 all threads of an inferior using a star wildcard. GDB accepts
1946 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
1947 refer to all threads of the current inferior. For example, "info
1950 * You can use "info threads -gid" to display the global thread ID of
1953 * The new convenience variable $_gthread holds the global number of
1956 * The new convenience variable $_inferior holds the number of the
1959 * GDB now displays the ID and name of the thread that hit a breakpoint
1960 or received a signal, if your program is multi-threaded. For
1963 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
1964 Thread 1 "main" received signal SIGINT, Interrupt.
1966 * Record btrace now supports non-stop mode.
1968 * Support for tracepoints on aarch64-linux was added in GDBserver.
1970 * The 'record instruction-history' command now indicates speculative execution
1971 when using the Intel Processor Trace recording format.
1973 * GDB now allows users to specify explicit locations, bypassing
1974 the linespec parser. This feature is also available to GDB/MI
1977 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
1978 GDB now is able to debug both AArch64 applications and ARM applications
1981 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
1982 including JIT compiling fast tracepoint's conditional expression bytecode
1985 * GDB now supports displaced stepping on AArch64 GNU/Linux.
1987 * "info threads", "info inferiors", "info display", "info checkpoints"
1988 and "maint info program-spaces" now list the corresponding items in
1989 ascending ID order, for consistency with all other "info" commands.
1991 * In Ada, the overloads selection menu has been enhanced to display the
1992 parameter types and the return types for the matching overloaded subprograms.
1996 maint set target-non-stop (on|off|auto)
1997 maint show target-non-stop
1998 Control whether GDB targets always operate in non-stop mode even if
1999 "set non-stop" is "off". The default is "auto", meaning non-stop
2000 mode is enabled if supported by the target.
2002 maint set bfd-sharing
2003 maint show bfd-sharing
2004 Control the reuse of bfd objects.
2007 show debug bfd-cache
2008 Control display of debugging info regarding bfd caching.
2012 Control display of debugging info regarding FreeBSD threads.
2014 set remote multiprocess-extensions-packet
2015 show remote multiprocess-extensions-packet
2016 Set/show the use of the remote protocol multiprocess extensions.
2018 set remote thread-events
2019 show remote thread-events
2020 Set/show the use of thread create/exit events.
2022 set ada print-signatures on|off
2023 show ada print-signatures"
2024 Control whether parameter types and return types are displayed in overloads
2025 selection menus. It is activated (@code{on}) by default.
2029 Controls the maximum size of memory, in bytes, that GDB will
2030 allocate for value contents. Prevents incorrect programs from
2031 causing GDB to allocate overly large buffers. Default is 64k.
2033 * The "disassemble" command accepts a new modifier: /s.
2034 It prints mixed source+disassembly like /m with two differences:
2035 - disassembled instructions are now printed in program order, and
2036 - and source for all relevant files is now printed.
2037 The "/m" option is now considered deprecated: its "source-centric"
2038 output hasn't proved useful in practice.
2040 * The "record instruction-history" command accepts a new modifier: /s.
2041 It behaves exactly like /m and prints mixed source+disassembly.
2043 * The "set scheduler-locking" command supports a new mode "replay".
2044 It behaves like "off" in record mode and like "on" in replay mode.
2046 * Support for various ROM monitors has been removed:
2048 target dbug dBUG ROM monitor for Motorola ColdFire
2049 target picobug Motorola picobug monitor
2050 target dink32 DINK32 ROM monitor for PowerPC
2051 target m32r Renesas M32R/D ROM monitor
2052 target mon2000 mon2000 ROM monitor
2053 target ppcbug PPCBUG ROM monitor for PowerPC
2055 * Support for reading/writing memory and extracting values on architectures
2056 whose memory is addressable in units of any integral multiple of 8 bits.
2059 Allows to break when an Ada exception is handled.
2061 * New remote packets
2064 Indicates that an exec system call was executed.
2066 exec-events feature in qSupported
2067 The qSupported packet allows GDB to request support for exec
2068 events using the new 'gdbfeature' exec-event, and the qSupported
2069 response can contain the corresponding 'stubfeature'. Set and
2070 show commands can be used to display whether these features are enabled.
2073 Equivalent to interrupting with the ^C character, but works in
2076 thread created stop reason (T05 create:...)
2077 Indicates that the thread was just created and is stopped at entry.
2079 thread exit stop reply (w exitcode;tid)
2080 Indicates that the thread has terminated.
2083 Enables/disables thread create and exit event reporting. For
2084 example, this is used in non-stop mode when GDB stops a set of
2085 threads and synchronously waits for the their corresponding stop
2086 replies. Without exit events, if one of the threads exits, GDB
2087 would hang forever not knowing that it should no longer expect a
2088 stop for that same thread.
2091 Indicates that there are no resumed threads left in the target (all
2092 threads are stopped). The remote stub reports support for this stop
2093 reply to GDB's qSupported query.
2096 Enables/disables catching syscalls from the inferior process.
2097 The remote stub reports support for this packet to GDB's qSupported query.
2099 syscall_entry stop reason
2100 Indicates that a syscall was just called.
2102 syscall_return stop reason
2103 Indicates that a syscall just returned.
2105 * Extended-remote exec events
2107 ** GDB now has support for exec events on extended-remote Linux targets.
2108 For such targets with Linux kernels 2.5.46 and later, this enables
2109 follow-exec-mode and exec catchpoints.
2111 set remote exec-event-feature-packet
2112 show remote exec-event-feature-packet
2113 Set/show the use of the remote exec event feature.
2115 * Thread names in remote protocol
2117 The reply to qXfer:threads:read may now include a name attribute for each
2120 * Target remote mode fork and exec events
2122 ** GDB now has support for fork and exec events on target remote mode
2123 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2124 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2125 fork and exec catchpoints.
2127 * Remote syscall events
2129 ** GDB now has support for catch syscall on remote Linux targets,
2130 currently enabled on x86/x86_64 architectures.
2132 set remote catch-syscall-packet
2133 show remote catch-syscall-packet
2134 Set/show the use of the remote catch syscall feature.
2138 ** The -var-set-format command now accepts the zero-hexadecimal
2139 format. It outputs data in hexadecimal format with zero-padding on the
2144 ** gdb.InferiorThread objects have a new attribute "global_num",
2145 which refers to the thread's global thread ID. The existing
2146 "num" attribute now refers to the thread's per-inferior number.
2147 See "Per-inferior thread numbers" above.
2148 ** gdb.InferiorThread objects have a new attribute "inferior", which
2149 is the Inferior object the thread belongs to.
2151 *** Changes in GDB 7.10
2153 * Support for process record-replay and reverse debugging on aarch64*-linux*
2154 targets has been added. GDB now supports recording of A64 instruction set
2155 including advance SIMD instructions.
2157 * Support for Sun's version of the "stabs" debug file format has been removed.
2159 * GDB now honors the content of the file /proc/PID/coredump_filter
2160 (PID is the process ID) on GNU/Linux systems. This file can be used
2161 to specify the types of memory mappings that will be included in a
2162 corefile. For more information, please refer to the manual page of
2163 "core(5)". GDB also has a new command: "set use-coredump-filter
2164 on|off". It allows to set whether GDB will read the content of the
2165 /proc/PID/coredump_filter file when generating a corefile.
2167 * The "info os" command on GNU/Linux can now display information on
2169 "info os cpus" Listing of all cpus/cores on the system
2171 * GDB has two new commands: "set serial parity odd|even|none" and
2172 "show serial parity". These allows to set or show parity for the
2175 * The "info source" command now displays the producer string if it was
2176 present in the debug info. This typically includes the compiler version
2177 and may include things like its command line arguments.
2179 * The "info dll", an alias of the "info sharedlibrary" command,
2180 is now available on all platforms.
2182 * Directory names supplied to the "set sysroot" commands may be
2183 prefixed with "target:" to tell GDB to access shared libraries from
2184 the target system, be it local or remote. This replaces the prefix
2185 "remote:". The default sysroot has been changed from "" to
2186 "target:". "remote:" is automatically converted to "target:" for
2187 backward compatibility.
2189 * The system root specified by "set sysroot" will be prepended to the
2190 filename of the main executable (if reported to GDB as absolute by
2191 the operating system) when starting processes remotely, and when
2192 attaching to already-running local or remote processes.
2194 * GDB now supports automatic location and retrieval of executable
2195 files from remote targets. Remote debugging can now be initiated
2196 using only a "target remote" or "target extended-remote" command
2197 (no "set sysroot" or "file" commands are required). See "New remote
2200 * The "dump" command now supports verilog hex format.
2202 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2204 * On GNU/Linux, GDB and gdbserver are now able to access executable
2205 and shared library files without a "set sysroot" command when
2206 attaching to processes running in different mount namespaces from
2207 the debugger. This makes it possible to attach to processes in
2208 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2209 See "New remote packets" below.
2211 * The "tui reg" command now provides completion for all of the
2212 available register groups, including target specific groups.
2214 * The HISTSIZE environment variable is no longer read when determining
2215 the size of GDB's command history. GDB now instead reads the dedicated
2216 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2217 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2222 ** Memory ports can now be unbuffered.
2226 ** gdb.Objfile objects have a new attribute "username",
2227 which is the name of the objfile as specified by the user,
2228 without, for example, resolving symlinks.
2229 ** You can now write frame unwinders in Python.
2230 ** gdb.Type objects have a new method "optimized_out",
2231 returning optimized out gdb.Value instance of this type.
2232 ** gdb.Value objects have new methods "reference_value" and
2233 "const_value" which return a reference to the value and a
2234 "const" version of the value respectively.
2238 maint print symbol-cache
2239 Print the contents of the symbol cache.
2241 maint print symbol-cache-statistics
2242 Print statistics of symbol cache usage.
2244 maint flush-symbol-cache
2245 Flush the contents of the symbol cache.
2249 Start branch trace recording using Branch Trace Store (BTS) format.
2252 Evaluate expression by using the compiler and print result.
2256 Explicit commands for enabling and disabling tui mode.
2259 set mpx bound on i386 and amd64
2260 Support for bound table investigation on Intel MPX enabled applications.
2264 Start branch trace recording using Intel Processor Trace format.
2267 Print information about branch tracing internals.
2269 maint btrace packet-history
2270 Print the raw branch tracing data.
2272 maint btrace clear-packet-history
2273 Discard the stored raw branch tracing data.
2276 Discard all branch tracing data. It will be fetched and processed
2277 anew by the next "record" command.
2282 Renamed from "set debug dwarf2-die".
2283 show debug dwarf-die
2284 Renamed from "show debug dwarf2-die".
2286 set debug dwarf-read
2287 Renamed from "set debug dwarf2-read".
2288 show debug dwarf-read
2289 Renamed from "show debug dwarf2-read".
2291 maint set dwarf always-disassemble
2292 Renamed from "maint set dwarf2 always-disassemble".
2293 maint show dwarf always-disassemble
2294 Renamed from "maint show dwarf2 always-disassemble".
2296 maint set dwarf max-cache-age
2297 Renamed from "maint set dwarf2 max-cache-age".
2298 maint show dwarf max-cache-age
2299 Renamed from "maint show dwarf2 max-cache-age".
2301 set debug dwarf-line
2302 show debug dwarf-line
2303 Control display of debugging info regarding DWARF line processing.
2306 show max-completions
2307 Set the maximum number of candidates to be considered during
2308 completion. The default value is 200. This limit allows GDB
2309 to avoid generating large completion lists, the computation of
2310 which can cause the debugger to become temporarily unresponsive.
2312 set history remove-duplicates
2313 show history remove-duplicates
2314 Control the removal of duplicate history entries.
2316 maint set symbol-cache-size
2317 maint show symbol-cache-size
2318 Control the size of the symbol cache.
2320 set|show record btrace bts buffer-size
2321 Set and show the size of the ring buffer used for branch tracing in
2323 The obtained size may differ from the requested size. Use "info
2324 record" to see the obtained buffer size.
2326 set debug linux-namespaces
2327 show debug linux-namespaces
2328 Control display of debugging info regarding Linux namespaces.
2330 set|show record btrace pt buffer-size
2331 Set and show the size of the ring buffer used for branch tracing in
2332 Intel Processor Trace format.
2333 The obtained size may differ from the requested size. Use "info
2334 record" to see the obtained buffer size.
2336 maint set|show btrace pt skip-pad
2337 Set and show whether PAD packets are skipped when computing the
2340 * The command 'thread apply all' can now support new option '-ascending'
2341 to call its specified command for all threads in ascending order.
2343 * Python/Guile scripting
2345 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2346 special section named `.debug_gdb_scripts'.
2348 * New remote packets
2350 qXfer:btrace-conf:read
2351 Return the branch trace configuration for the current thread.
2353 Qbtrace-conf:bts:size
2354 Set the requested ring buffer size for branch tracing in BTS format.
2357 Enable Intel Processor Trace-based branch tracing for the current
2358 process. The remote stub reports support for this packet to GDB's
2361 Qbtrace-conf:pt:size
2362 Set the requested ring buffer size for branch tracing in Intel Processor
2366 Indicates a memory breakpoint instruction was executed, irrespective
2367 of whether it was GDB that planted the breakpoint or the breakpoint
2368 is hardcoded in the program. This is required for correct non-stop
2372 Indicates the target stopped for a hardware breakpoint. This is
2373 required for correct non-stop mode operation.
2376 Return information about files on the remote system.
2378 qXfer:exec-file:read
2379 Return the full absolute name of the file that was executed to
2380 create a process running on the remote system.
2383 Select the filesystem on which vFile: operations with filename
2384 arguments will operate. This is required for GDB to be able to
2385 access files on remote targets where the remote stub does not
2386 share a common filesystem with the inferior(s).
2389 Indicates that a fork system call was executed.
2392 Indicates that a vfork system call was executed.
2394 vforkdone stop reason
2395 Indicates that a vfork child of the specified process has executed
2396 an exec or exit, allowing the vfork parent to resume execution.
2398 fork-events and vfork-events features in qSupported
2399 The qSupported packet allows GDB to request support for fork and
2400 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2401 and the qSupported response can contain the corresponding
2402 'stubfeatures'. Set and show commands can be used to display
2403 whether these features are enabled.
2405 * Extended-remote fork events
2407 ** GDB now has support for fork events on extended-remote Linux
2408 targets. For targets with Linux kernels 2.5.60 and later, this
2409 enables follow-fork-mode and detach-on-fork for both fork and
2410 vfork, as well as fork and vfork catchpoints.
2412 * The info record command now shows the recording format and the
2413 branch tracing configuration for the current thread when using
2414 the btrace record target.
2415 For the BTS format, it shows the ring buffer size.
2417 * GDB now has support for DTrace USDT (Userland Static Defined
2418 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2420 * GDB now supports access to vector registers on S/390 GNU/Linux
2423 * Removed command line options
2425 -xdb HP-UX XDB compatibility mode.
2427 * Removed targets and native configurations
2429 HP/PA running HP-UX hppa*-*-hpux*
2430 Itanium running HP-UX ia64-*-hpux*
2432 * New configure options
2435 This configure option allows the user to build GDB with support for
2436 Intel Processor Trace (default: auto). This requires libipt.
2438 --with-libipt-prefix=PATH
2439 Specify the path to the version of libipt that GDB should use.
2440 $PATH/include should contain the intel-pt.h header and
2441 $PATH/lib should contain the libipt.so library.
2443 *** Changes in GDB 7.9.1
2447 ** Xmethods can now specify a result type.
2449 *** Changes in GDB 7.9
2451 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2455 ** You can now access frame registers from Python scripts.
2456 ** New attribute 'producer' for gdb.Symtab objects.
2457 ** gdb.Objfile objects have a new attribute "progspace",
2458 which is the gdb.Progspace object of the containing program space.
2459 ** gdb.Objfile objects have a new attribute "owner".
2460 ** gdb.Objfile objects have a new attribute "build_id",
2461 which is the build ID generated when the file was built.
2462 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2463 ** A new event "gdb.clear_objfiles" has been added, triggered when
2464 selecting a new file to debug.
2465 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2466 ** New function gdb.lookup_objfile.
2468 New events which are triggered when GDB modifies the state of the
2471 ** gdb.events.inferior_call_pre: Function call is about to be made.
2472 ** gdb.events.inferior_call_post: Function call has just been made.
2473 ** gdb.events.memory_changed: A memory location has been altered.
2474 ** gdb.events.register_changed: A register has been altered.
2476 * New Python-based convenience functions:
2478 ** $_caller_is(name [, number_of_frames])
2479 ** $_caller_matches(regexp [, number_of_frames])
2480 ** $_any_caller_is(name [, number_of_frames])
2481 ** $_any_caller_matches(regexp [, number_of_frames])
2483 * GDB now supports the compilation and injection of source code into
2484 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2485 to compile the source code to object code, and if successful, inject
2486 and execute that code within the current context of the inferior.
2487 Currently the C language is supported. The commands used to
2488 interface with this new feature are:
2490 compile code [-raw|-r] [--] [source code]
2491 compile file [-raw|-r] filename
2495 demangle [-l language] [--] name
2496 Demangle "name" in the specified language, or the current language
2497 if elided. This command is renamed from the "maint demangle" command.
2498 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2499 as "maint demangler-warning".
2501 queue-signal signal-name-or-number
2502 Queue a signal to be delivered to the thread when it is resumed.
2504 add-auto-load-scripts-directory directory
2505 Add entries to the list of directories from which to load auto-loaded
2508 maint print user-registers
2509 List all currently available "user" registers.
2511 compile code [-r|-raw] [--] [source code]
2512 Compile, inject, and execute in the inferior the executable object
2513 code produced by compiling the provided source code.
2515 compile file [-r|-raw] filename
2516 Compile and inject into the inferior the executable object code
2517 produced by compiling the source code stored in the filename
2520 * On resume, GDB now always passes the signal the program had stopped
2521 for to the thread the signal was sent to, even if the user changed
2522 threads before resuming. Previously GDB would often (but not
2523 always) deliver the signal to the thread that happens to be current
2526 * Conversely, the "signal" command now consistently delivers the
2527 requested signal to the current thread. GDB now asks for
2528 confirmation if the program had stopped for a signal and the user
2529 switched threads meanwhile.
2531 * "breakpoint always-inserted" modes "off" and "auto" merged.
2533 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2534 won't remove breakpoints from the target until all threads stop,
2535 even in non-stop mode. The "auto" mode has been removed, and "off"
2536 is now the default mode.
2540 set debug symbol-lookup
2541 show debug symbol-lookup
2542 Control display of debugging info regarding symbol lookup.
2546 ** The -list-thread-groups command outputs an exit-code field for
2547 inferiors that have exited.
2551 MIPS SDE mips*-sde*-elf*
2555 Support for these obsolete configurations has been removed.
2557 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2558 SGI Irix-5.x mips-*-irix5*
2559 SGI Irix-6.x mips-*-irix6*
2560 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2561 VAX running Ultrix vax-*-ultrix*
2563 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2564 and "assf"), have been removed. Use the "sharedlibrary" command, or
2565 its alias "share", instead.
2567 *** Changes in GDB 7.8
2569 * New command line options
2572 This is an alias for the --data-directory option.
2574 * GDB supports printing and modifying of variable length automatic arrays
2575 as specified in ISO C99.
2577 * The ARM simulator now supports instruction level tracing
2578 with or without disassembly.
2582 GDB now has support for scripting using Guile. Whether this is
2583 available is determined at configure time.
2584 Guile version 2.0 or greater is required.
2585 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2587 * New commands (for set/show, see "New options" below)
2591 Invoke CODE by passing it to the Guile interpreter.
2595 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2597 info auto-load guile-scripts [regexp]
2598 Print the list of automatically loaded Guile scripts.
2600 * The source command is now capable of sourcing Guile scripts.
2601 This feature is dependent on the debugger being built with Guile support.
2605 set print symbol-loading (off|brief|full)
2606 show print symbol-loading
2607 Control whether to print informational messages when loading symbol
2608 information for a file. The default is "full", but when debugging
2609 programs with large numbers of shared libraries the amount of output
2610 becomes less useful.
2612 set guile print-stack (none|message|full)
2613 show guile print-stack
2614 Show a stack trace when an error is encountered in a Guile script.
2616 set auto-load guile-scripts (on|off)
2617 show auto-load guile-scripts
2618 Control auto-loading of Guile script files.
2620 maint ada set ignore-descriptive-types (on|off)
2621 maint ada show ignore-descriptive-types
2622 Control whether the debugger should ignore descriptive types in Ada
2623 programs. The default is not to ignore the descriptive types. See
2624 the user manual for more details on descriptive types and the intended
2625 usage of this option.
2627 set auto-connect-native-target
2629 Control whether GDB is allowed to automatically connect to the
2630 native target for the run, attach, etc. commands when not connected
2631 to any target yet. See also "target native" below.
2633 set record btrace replay-memory-access (read-only|read-write)
2634 show record btrace replay-memory-access
2635 Control what memory accesses are allowed during replay.
2637 maint set target-async (on|off)
2638 maint show target-async
2639 This controls whether GDB targets operate in synchronous or
2640 asynchronous mode. Normally the default is asynchronous, if it is
2641 available; but this can be changed to more easily debug problems
2642 occurring only in synchronous mode.
2644 set mi-async (on|off)
2646 Control whether MI asynchronous mode is preferred. This supersedes
2647 "set target-async" of previous GDB versions.
2649 * "set target-async" is deprecated as a CLI option and is now an alias
2650 for "set mi-async" (only puts MI into async mode).
2652 * Background execution commands (e.g., "c&", "s&", etc.) are now
2653 possible ``out of the box'' if the target supports them. Previously
2654 the user would need to explicitly enable the possibility with the
2655 "set target-async on" command.
2657 * New features in the GDB remote stub, GDBserver
2659 ** New option --debug-format=option1[,option2,...] allows one to add
2660 additional text to each output. At present only timestamps
2661 are supported: --debug-format=timestamps.
2662 Timestamps can also be turned on with the
2663 "monitor set debug-format timestamps" command from GDB.
2665 * The 'record instruction-history' command now starts counting instructions
2666 at one. This also affects the instruction ranges reported by the
2667 'record function-call-history' command when given the /i modifier.
2669 * The command 'record function-call-history' supports a new modifier '/c' to
2670 indent the function names based on their call stack depth.
2671 The fields for the '/i' and '/l' modifier have been reordered.
2672 The source line range is now prefixed with 'at'.
2673 The instruction range is now prefixed with 'inst'.
2674 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2675 "record instruction-history" and "list" commands.
2677 * The ranges given as arguments to the 'record function-call-history' and
2678 'record instruction-history' commands are now inclusive.
2680 * The btrace record target now supports the 'record goto' command.
2681 For locations inside the execution trace, the back trace is computed
2682 based on the information stored in the execution trace.
2684 * The btrace record target supports limited reverse execution and replay.
2685 The target does not record data and therefore does not allow reading
2686 memory or registers.
2688 * The "catch syscall" command now works on s390*-linux* targets.
2690 * The "compare-sections" command is no longer specific to target
2691 remote. It now works with all targets.
2693 * All native targets are now consistently called "native".
2694 Consequently, the "target child", "target GNU", "target djgpp",
2695 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2696 commands have been replaced with "target native". The QNX/NTO port
2697 leaves the "procfs" target in place and adds a "native" target for
2698 consistency with other ports. The impact on users should be minimal
2699 as these commands previously either throwed an error, or were
2700 no-ops. The target's name is visible in the output of the following
2701 commands: "help target", "info target", "info files", "maint print
2704 * The "target native" command now connects to the native target. This
2705 can be used to launch native programs even when "set
2706 auto-connect-native-target" is set to off.
2708 * GDB now supports access to Intel MPX registers on GNU/Linux.
2710 * Support for Intel AVX-512 registers on GNU/Linux.
2711 Support displaying and modifying Intel AVX-512 registers
2712 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2714 * New remote packets
2716 qXfer:btrace:read's annex
2717 The qXfer:btrace:read packet supports a new annex 'delta' to read
2718 branch trace incrementally.
2722 ** Valid Python operations on gdb.Value objects representing
2723 structs/classes invoke the corresponding overloaded operators if
2725 ** New `Xmethods' feature in the Python API. Xmethods are
2726 additional methods or replacements for existing methods of a C++
2727 class. This feature is useful for those cases where a method
2728 defined in C++ source code could be inlined or optimized out by
2729 the compiler, making it unavailable to GDB.
2732 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2734 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2735 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2736 its alias "share", instead.
2738 * The commands "set remotebaud" and "show remotebaud" are no longer
2739 supported. Use "set serial baud" and "show serial baud" (respectively)
2744 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2745 target-async". The latter is left as a deprecated alias of the
2746 former for backward compatibility. If the target supports it,
2747 CLI background execution commands are now always possible by
2748 default, independently of whether the frontend stated a
2749 preference for asynchronous execution with "-gdb-set mi-async".
2750 Previously "-gdb-set target-async off" affected both MI execution
2751 commands and CLI execution commands.
2753 *** Changes in GDB 7.7
2755 * Improved support for process record-replay and reverse debugging on
2756 arm*-linux* targets. Support for thumb32 and syscall instruction
2757 recording has been added.
2759 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2761 * GDB now supports Fission DWP file format version 2.
2762 http://gcc.gnu.org/wiki/DebugFission
2764 * New convenience function "$_isvoid", to check whether an expression
2765 is void. A void expression is an expression where the type of the
2766 result is "void". For example, some convenience variables may be
2767 "void" when evaluated (e.g., "$_exitcode" before the execution of
2768 the program being debugged; or an undefined convenience variable).
2769 Another example, when calling a function whose return type is
2772 * The "maintenance print objfiles" command now takes an optional regexp.
2774 * The "catch syscall" command now works on arm*-linux* targets.
2776 * GDB now consistently shows "<not saved>" when printing values of
2777 registers the debug info indicates have not been saved in the frame
2778 and there's nowhere to retrieve them from
2779 (callee-saved/call-clobbered registers):
2784 (gdb) info registers rax
2787 Before, the former would print "<optimized out>", and the latter
2788 "*value not available*".
2790 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
2795 ** Frame filters and frame decorators have been added.
2796 ** Temporary breakpoints are now supported.
2797 ** Line tables representation has been added.
2798 ** New attribute 'parent_type' for gdb.Field objects.
2799 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
2800 ** New attribute 'name' for gdb.Type objects.
2804 Nios II ELF nios2*-*-elf
2805 Nios II GNU/Linux nios2*-*-linux
2806 Texas Instruments MSP430 msp430*-*-elf
2808 * Removed native configurations
2810 Support for these a.out NetBSD and OpenBSD obsolete configurations has
2811 been removed. ELF variants of these configurations are kept supported.
2813 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
2814 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
2815 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
2816 i[34567]86-*-openbsd3.[0-3]
2817 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
2818 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
2819 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
2823 Like "catch throw", but catches a re-thrown exception.
2824 maint check-psymtabs
2825 Renamed from old "maint check-symtabs".
2827 Perform consistency checks on symtabs.
2828 maint expand-symtabs
2829 Expand symtabs matching an optional regexp.
2832 Display the details of GDB configure-time options.
2834 maint set|show per-command
2835 maint set|show per-command space
2836 maint set|show per-command time
2837 maint set|show per-command symtab
2838 Enable display of per-command gdb resource usage.
2840 remove-symbol-file FILENAME
2841 remove-symbol-file -a ADDRESS
2842 Remove a symbol file added via add-symbol-file. The file to remove
2843 can be identified by its filename or by an address that lies within
2844 the boundaries of this symbol file in memory.
2847 info exceptions REGEXP
2848 Display the list of Ada exceptions defined in the program being
2849 debugged. If provided, only the exceptions whose names match REGEXP
2854 set debug symfile off|on
2856 Control display of debugging info regarding reading symbol files and
2857 symbol tables within those files
2859 set print raw frame-arguments
2860 show print raw frame-arguments
2861 Set/show whether to print frame arguments in raw mode,
2862 disregarding any defined pretty-printers.
2864 set remote trace-status-packet
2865 show remote trace-status-packet
2866 Set/show the use of remote protocol qTStatus packet.
2870 Control display of debugging messages related to Nios II targets.
2874 Control whether target-assisted range stepping is enabled.
2876 set startup-with-shell
2877 show startup-with-shell
2878 Specifies whether Unix child processes are started via a shell or
2883 Use the target memory cache for accesses to the code segment. This
2884 improves performance of remote debugging (particularly disassembly).
2886 * You can now use a literal value 'unlimited' for options that
2887 interpret 0 or -1 as meaning "unlimited". E.g., "set
2888 trace-buffer-size unlimited" is now an alias for "set
2889 trace-buffer-size -1" and "set height unlimited" is now an alias for
2892 * The "set debug symtab-create" debugging option of GDB has been changed to
2893 accept a verbosity level. 0 means "off", 1 provides basic debugging
2894 output, and values of 2 or greater provides more verbose output.
2896 * New command-line options
2898 Display the details of GDB configure-time options.
2900 * The command 'tsave' can now support new option '-ctf' to save trace
2901 buffer in Common Trace Format.
2903 * Newly installed $prefix/bin/gcore acts as a shell interface for the
2906 * GDB now implements the C++ 'typeid' operator.
2908 * The new convenience variable $_exception holds the exception being
2909 thrown or caught at an exception-related catchpoint.
2911 * The exception-related catchpoints, like "catch throw", now accept a
2912 regular expression which can be used to filter exceptions by type.
2914 * The new convenience variable $_exitsignal is automatically set to
2915 the terminating signal number when the program being debugged dies
2916 due to an uncaught signal.
2920 ** All MI commands now accept an optional "--language" option.
2921 Support for this feature can be verified by using the "-list-features"
2922 command, which should contain "language-option".
2924 ** The new command -info-gdb-mi-command allows the user to determine
2925 whether a GDB/MI command is supported or not.
2927 ** The "^error" result record returned when trying to execute an undefined
2928 GDB/MI command now provides a variable named "code" whose content is the
2929 "undefined-command" error code. Support for this feature can be verified
2930 by using the "-list-features" command, which should contain
2931 "undefined-command-error-code".
2933 ** The -trace-save MI command can optionally save trace buffer in Common
2936 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
2938 ** The command -data-list-register-values now accepts an optional
2939 "--skip-unavailable" option. When used, only the available registers
2942 ** The new command -trace-frame-collected dumps collected variables,
2943 computed expressions, tvars, memory and registers in a traceframe.
2945 ** The commands -stack-list-locals, -stack-list-arguments and
2946 -stack-list-variables now accept an option "--skip-unavailable".
2947 When used, only the available locals or arguments are displayed.
2949 ** The -exec-run command now accepts an optional "--start" option.
2950 When used, the command follows the same semantics as the "start"
2951 command, stopping the program's execution at the start of its
2952 main subprogram. Support for this feature can be verified using
2953 the "-list-features" command, which should contain
2954 "exec-run-start-option".
2956 ** The new commands -catch-assert and -catch-exceptions insert
2957 catchpoints stopping the program when Ada exceptions are raised.
2959 ** The new command -info-ada-exceptions provides the equivalent of
2960 the new "info exceptions" command.
2962 * New system-wide configuration scripts
2963 A GDB installation now provides scripts suitable for use as system-wide
2964 configuration scripts for the following systems:
2968 * GDB now supports target-assigned range stepping with remote targets.
2969 This improves the performance of stepping source lines by reducing
2970 the number of control packets from/to GDB. See "New remote packets"
2973 * GDB now understands the element 'tvar' in the XML traceframe info.
2974 It has the id of the collected trace state variables.
2976 * On S/390 targets that provide the transactional-execution feature,
2977 the program interruption transaction diagnostic block (TDB) is now
2978 represented as a number of additional "registers" in GDB.
2980 * New remote packets
2984 The vCont packet supports a new 'r' action, that tells the remote
2985 stub to step through an address range itself, without GDB
2986 involvemement at each single-step.
2988 qXfer:libraries-svr4:read's annex
2989 The previously unused annex of the qXfer:libraries-svr4:read packet
2990 is now used to support passing an argument list. The remote stub
2991 reports support for this argument list to GDB's qSupported query.
2992 The defined arguments are "start" and "prev", used to reduce work
2993 necessary for library list updating, resulting in significant
2996 * New features in the GDB remote stub, GDBserver
2998 ** GDBserver now supports target-assisted range stepping. Currently
2999 enabled on x86/x86_64 GNU/Linux targets.
3001 ** GDBserver now adds element 'tvar' in the XML in the reply to
3002 'qXfer:traceframe-info:read'. It has the id of the collected
3003 trace state variables.
3005 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3008 * New 'z' formatter for printing and examining memory, this displays the
3009 value as hexadecimal zero padded on the left to the size of the type.
3011 * GDB can now use Windows x64 unwinding data.
3013 * The "set remotebaud" command has been replaced by "set serial baud".
3014 Similarly, "show remotebaud" has been replaced by "show serial baud".
3015 The "set remotebaud" and "show remotebaud" commands are still available
3016 to provide backward compatibility with older versions of GDB.
3018 *** Changes in GDB 7.6
3020 * Target record has been renamed to record-full.
3021 Record/replay is now enabled with the "record full" command.
3022 This also affects settings that are associated with full record/replay
3023 that have been moved from "set/show record" to "set/show record full":
3025 set|show record full insn-number-max
3026 set|show record full stop-at-limit
3027 set|show record full memory-query
3029 * A new record target "record-btrace" has been added. The new target
3030 uses hardware support to record the control-flow of a process. It
3031 does not support replaying the execution, but it implements the
3032 below new commands for investigating the recorded execution log.
3033 This new recording method can be enabled using:
3037 The "record-btrace" target is only available on Intel Atom processors
3038 and requires a Linux kernel 2.6.32 or later.
3040 * Two new commands have been added for record/replay to give information
3041 about the recorded execution without having to replay the execution.
3042 The commands are only supported by "record btrace".
3044 record instruction-history prints the execution history at
3045 instruction granularity
3047 record function-call-history prints the execution history at
3048 function granularity
3050 * New native configurations
3052 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3053 FreeBSD/powerpc powerpc*-*-freebsd
3054 x86_64/Cygwin x86_64-*-cygwin*
3055 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3059 ARM AArch64 aarch64*-*-elf
3060 ARM AArch64 GNU/Linux aarch64*-*-linux
3061 Lynx 178 PowerPC powerpc-*-lynx*178
3062 x86_64/Cygwin x86_64-*-cygwin*
3063 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3065 * If the configured location of system.gdbinit file (as given by the
3066 --with-system-gdbinit option at configure time) is in the
3067 data-directory (as specified by --with-gdb-datadir at configure
3068 time) or in one of its subdirectories, then GDB will look for the
3069 system-wide init file in the directory specified by the
3070 --data-directory command-line option.
3072 * New command line options:
3074 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3075 other initialization files, unlike -nx which disables all of them.
3077 * Removed command line options
3079 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3082 * The 'ptype' and 'whatis' commands now accept an argument to control
3085 * 'info proc' now works on some core files.
3089 ** Vectors can be created with gdb.Type.vector.
3091 ** Python's atexit.register now works in GDB.
3093 ** Types can be pretty-printed via a Python API.
3095 ** Python 3 is now supported (in addition to Python 2.4 or later)
3097 ** New class gdb.Architecture exposes GDB's internal representation
3098 of architecture in the Python API.
3100 ** New method Frame.architecture returns the gdb.Architecture object
3101 corresponding to the frame's architecture.
3103 * New Python-based convenience functions:
3105 ** $_memeq(buf1, buf2, length)
3106 ** $_streq(str1, str2)
3108 ** $_regex(str, regex)
3110 * The 'cd' command now defaults to using '~' (the home directory) if not
3113 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3114 default for GCC since November 2000.
3116 * The command 'forward-search' can now be abbreviated as 'fo'.
3118 * The command 'info tracepoints' can now display 'installed on target'
3119 or 'not installed on target' for each non-pending location of tracepoint.
3121 * New configure options
3123 --enable-libmcheck/--disable-libmcheck
3124 By default, development versions are built with -lmcheck on hosts
3125 that support it, in order to help track memory corruption issues.
3126 Release versions, on the other hand, are built without -lmcheck
3127 by default. The --enable-libmcheck/--disable-libmcheck configure
3128 options allow the user to override that default.
3129 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3130 This configure option allows the user to build GDB with
3131 libbabeltrace using which GDB can read Common Trace Format data.
3133 * New commands (for set/show, see "New options" below)
3136 Catch signals. This is similar to "handle", but allows commands and
3137 conditions to be attached.
3140 List the BFDs known to GDB.
3142 python-interactive [command]
3144 Start a Python interactive prompt, or evaluate the optional command
3145 and print the result of expressions.
3148 "py" is a new alias for "python".
3150 enable type-printer [name]...
3151 disable type-printer [name]...
3152 Enable or disable type printers.
3156 ** For the Renesas Super-H architecture, the "regs" command has been removed
3157 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3162 set print type methods (on|off)
3163 show print type methods
3164 Control whether method declarations are displayed by "ptype".
3165 The default is to show them.
3167 set print type typedefs (on|off)
3168 show print type typedefs
3169 Control whether typedef definitions are displayed by "ptype".
3170 The default is to show them.
3172 set filename-display basename|relative|absolute
3173 show filename-display
3174 Control the way in which filenames is displayed.
3175 The default is "relative", which preserves previous behavior.
3177 set trace-buffer-size
3178 show trace-buffer-size
3179 Request target to change the size of trace buffer.
3181 set remote trace-buffer-size-packet auto|on|off
3182 show remote trace-buffer-size-packet
3183 Control the use of the remote protocol `QTBuffer:size' packet.
3187 Control display of debugging messages related to ARM AArch64.
3190 set debug coff-pe-read
3191 show debug coff-pe-read
3192 Control display of debugging messages related to reading of COFF/PE
3197 Control display of debugging messages related to Mach-O symbols
3200 set debug notification
3201 show debug notification
3202 Control display of debugging info for async remote notification.
3206 ** Command parameter changes are now notified using new async record
3207 "=cmd-param-changed".
3208 ** Trace frame changes caused by command "tfind" are now notified using
3209 new async record "=traceframe-changed".
3210 ** The creation, deletion and modification of trace state variables
3211 are now notified using new async records "=tsv-created",
3212 "=tsv-deleted" and "=tsv-modified".
3213 ** The start and stop of process record are now notified using new
3214 async record "=record-started" and "=record-stopped".
3215 ** Memory changes are now notified using new async record
3217 ** The data-disassemble command response will include a "fullname" field
3218 containing the absolute file name when source has been requested.
3219 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3220 command, to allow pattern filling of memory areas.
3221 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3222 library load/unload events.
3223 ** The response to breakpoint commands and breakpoint async records
3224 includes an "installed" field containing a boolean state about each
3225 non-pending tracepoint location is whether installed on target or not.
3226 ** Output of the "-trace-status" command includes a "trace-file" field
3227 containing the name of the trace file being examined. This field is
3228 optional, and only present when examining a trace file.
3229 ** The "fullname" field is now always present along with the "file" field,
3230 even if the file cannot be found by GDB.
3232 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3233 You must have the LZMA library available when configuring GDB for this
3234 feature to be enabled. For more information, see:
3235 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3237 * New remote packets
3240 Set the size of trace buffer. The remote stub reports support for this
3241 packet to gdb's qSupported query.
3244 Enable Branch Trace Store (BTS)-based branch tracing for the current
3245 thread. The remote stub reports support for this packet to gdb's
3249 Disable branch tracing for the current thread. The remote stub reports
3250 support for this packet to gdb's qSupported query.
3253 Read the traced branches for the current thread. The remote stub
3254 reports support for this packet to gdb's qSupported query.
3256 *** Changes in GDB 7.5
3258 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3259 for more x32 ABI info.
3261 * GDB now supports access to MIPS DSP registers on Linux targets.
3263 * GDB now supports debugging microMIPS binaries.
3265 * The "info os" command on GNU/Linux can now display information on
3266 several new classes of objects managed by the operating system:
3267 "info os procgroups" lists process groups
3268 "info os files" lists file descriptors
3269 "info os sockets" lists internet-domain sockets
3270 "info os shm" lists shared-memory regions
3271 "info os semaphores" lists semaphores
3272 "info os msg" lists message queues
3273 "info os modules" lists loaded kernel modules
3275 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3276 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3277 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3278 options and inspect the probe arguments using the new $_probe_arg family
3279 of convenience variables. You can obtain more information about SystemTap
3280 in <http://sourceware.org/systemtap/>.
3282 * GDB now supports reversible debugging on ARM, it allows you to
3283 debug basic ARM and THUMB instructions, and provides
3284 record/replay support.
3286 * The option "symbol-reloading" has been deleted as it is no longer used.
3290 ** GDB commands implemented in Python can now be put in command class
3293 ** The "maint set python print-stack on|off" is now deleted.
3295 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3296 apply "flag enum"-style pretty-printing to any enum.
3298 ** gdb.lookup_symbol can now work when there is no current frame.
3300 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3301 the source at which the symbol was defined.
3303 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3304 method 'value'. The former indicates whether the symbol needs a
3305 frame in order to compute its value, and the latter computes the
3308 ** A new method 'referenced_value' on gdb.Value objects which can
3309 dereference pointer as well as C++ reference values.
3311 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3312 which return the global and static blocks (as gdb.Block objects),
3313 of the underlying symbol table, respectively.
3315 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3316 object associated with a PC value.
3318 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3319 of the address range occupied by code for the current source line.
3321 * Go language support.
3322 GDB now supports debugging programs written in the Go programming
3325 * GDBserver now supports stdio connections.
3326 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3328 * The binary "gdbtui" can no longer be built or installed.
3329 Use "gdb -tui" instead.
3331 * GDB will now print "flag" enums specially. A flag enum is one where
3332 all the enumerator values have no bits in common when pairwise
3333 "and"ed. When printing a value whose type is a flag enum, GDB will
3334 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3335 (gdb) print (enum E) 3
3338 * The filename part of a linespec will now match trailing components
3339 of a source file name. For example, "break gcc/expr.c:1000" will
3340 now set a breakpoint in build/gcc/expr.c, but not
3341 build/libcpp/expr.c.
3343 * The "info proc" and "generate-core-file" commands will now also
3344 work on remote targets connected to GDBserver on Linux.
3346 * The command "info catch" has been removed. It has been disabled
3347 since December 2007.
3349 * The "catch exception" and "catch assert" commands now accept
3350 a condition at the end of the command, much like the "break"
3351 command does. For instance:
3353 (gdb) catch exception Constraint_Error if Barrier = True
3355 Previously, it was possible to add a condition to such catchpoints,
3356 but it had to be done as a second step, after the catchpoint had been
3357 created, using the "condition" command.
3359 * The "info static-tracepoint-marker" command will now also work on
3360 native Linux targets with in-process agent.
3362 * GDB can now set breakpoints on inlined functions.
3364 * The .gdb_index section has been updated to include symbols for
3365 inlined functions. GDB will ignore older .gdb_index sections by
3366 default, which could cause symbol files to be loaded more slowly
3367 until their .gdb_index sections can be recreated. The new command
3368 "set use-deprecated-index-sections on" will cause GDB to use any older
3369 .gdb_index sections it finds. This will restore performance, but the
3370 ability to set breakpoints on inlined functions will be lost in symbol
3371 files with older .gdb_index sections.
3373 The .gdb_index section has also been updated to record more information
3374 about each symbol. This speeds up the "info variables", "info functions"
3375 and "info types" commands when used with programs having the .gdb_index
3376 section, as well as speeding up debugging with shared libraries using
3377 the .gdb_index section.
3379 * Ada support for GDB/MI Variable Objects has been added.
3381 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3386 ** New command -info-os is the MI equivalent of "info os".
3388 ** Output logs ("set logging" and related) now include MI output.
3392 ** "set use-deprecated-index-sections on|off"
3393 "show use-deprecated-index-sections on|off"
3394 Controls the use of deprecated .gdb_index sections.
3396 ** "catch load" and "catch unload" can be used to stop when a shared
3397 library is loaded or unloaded, respectively.
3399 ** "enable count" can be used to auto-disable a breakpoint after
3402 ** "info vtbl" can be used to show the virtual method tables for
3403 C++ and Java objects.
3405 ** "explore" and its sub commands "explore value" and "explore type"
3406 can be used to recursively explore values and types of
3407 expressions. These commands are available only if GDB is
3408 configured with '--with-python'.
3410 ** "info auto-load" shows status of all kinds of auto-loaded files,
3411 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3412 sequences of commands files, "info auto-load python-scripts"
3413 shows status of auto-loading Python script files,
3414 "info auto-load local-gdbinit" shows status of loading init file
3415 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3416 status of inferior specific thread debugging shared library loading.
3418 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3419 and "show auto-load-scripts" commands have been deprecated, use their
3420 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3421 and "show auto-load python-scripts" counterparts instead.
3423 ** "dprintf location,format,args..." creates a dynamic printf, which
3424 is basically a breakpoint that does a printf and immediately
3425 resumes your program's execution, so it is like a printf that you
3426 can insert dynamically at runtime instead of at compiletime.
3428 ** "set print symbol"
3430 Controls whether GDB attempts to display the symbol, if any,
3431 corresponding to addresses it prints. This defaults to "on", but
3432 you can set it to "off" to restore GDB's previous behavior.
3434 * Deprecated commands
3436 ** For the Renesas Super-H architecture, the "regs" command has been
3437 deprecated, and "info all-registers" should be used instead.
3441 Renesas RL78 rl78-*-elf
3442 HP OpenVMS ia64 ia64-hp-openvms*
3444 * GDBserver supports evaluation of breakpoint conditions. When
3445 support is advertised by GDBserver, GDB may be told to send the
3446 breakpoint conditions in bytecode form to GDBserver. GDBserver
3447 will only report the breakpoint trigger to GDB when its condition
3452 set mips compression
3453 show mips compression
3454 Select the compressed ISA encoding used in functions that have no symbol
3455 information available. The encoding can be set to either of:
3458 and is updated automatically from ELF file flags if available.
3460 set breakpoint condition-evaluation
3461 show breakpoint condition-evaluation
3462 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3463 GDBserver ("target"). Default option "auto" chooses the most efficient
3465 This option can improve debugger efficiency depending on the speed of the
3469 Disable auto-loading globally.
3472 Show auto-loading setting of all kinds of auto-loaded files.
3474 set auto-load gdb-scripts on|off
3475 show auto-load gdb-scripts
3476 Control auto-loading of GDB canned sequences of commands files.
3478 set auto-load python-scripts on|off
3479 show auto-load python-scripts
3480 Control auto-loading of Python script files.
3482 set auto-load local-gdbinit on|off
3483 show auto-load local-gdbinit
3484 Control loading of init file (.gdbinit) from current directory.
3486 set auto-load libthread-db on|off
3487 show auto-load libthread-db
3488 Control auto-loading of inferior specific thread debugging shared library.
3490 set auto-load scripts-directory <dir1>[:<dir2>...]
3491 show auto-load scripts-directory
3492 Set a list of directories from which to load auto-loaded scripts.
3493 Automatically loaded Python scripts and GDB scripts are located in one
3494 of the directories listed by this option.
3495 The delimiter (':' above) may differ according to the host platform.
3497 set auto-load safe-path <dir1>[:<dir2>...]
3498 show auto-load safe-path
3499 Set a list of directories from which it is safe to auto-load files.
3500 The delimiter (':' above) may differ according to the host platform.
3502 set debug auto-load on|off
3503 show debug auto-load
3504 Control display of debugging info for auto-loading the files above.
3506 set dprintf-style gdb|call|agent
3508 Control the way in which a dynamic printf is performed; "gdb"
3509 requests a GDB printf command, while "call" causes dprintf to call a
3510 function in the inferior. "agent" requests that the target agent
3511 (such as GDBserver) do the printing.
3513 set dprintf-function <expr>
3514 show dprintf-function
3515 set dprintf-channel <expr>
3516 show dprintf-channel
3517 Set the function and optional first argument to the call when using
3518 the "call" style of dynamic printf.
3520 set disconnected-dprintf on|off
3521 show disconnected-dprintf
3522 Control whether agent-style dynamic printfs continue to be in effect
3523 after GDB disconnects.
3525 * New configure options
3527 --with-auto-load-dir
3528 Configure default value for the 'set auto-load scripts-directory'
3529 setting above. It defaults to '$debugdir:$datadir/auto-load',
3530 $debugdir representing global debugging info directories (available
3531 via 'show debug-file-directory') and $datadir representing GDB's data
3532 directory (available via 'show data-directory').
3534 --with-auto-load-safe-path
3535 Configure default value for the 'set auto-load safe-path' setting
3536 above. It defaults to the --with-auto-load-dir setting.
3538 --without-auto-load-safe-path
3539 Set 'set auto-load safe-path' to '/', effectively disabling this
3542 * New remote packets
3544 z0/z1 conditional breakpoints extension
3546 The z0/z1 breakpoint insertion packets have been extended to carry
3547 a list of conditional expressions over to the remote stub depending on the
3548 condition evaluation mode. The use of this extension can be controlled
3549 via the "set remote conditional-breakpoints-packet" command.
3553 Specify the signals which the remote stub may pass to the debugged
3554 program without GDB involvement.
3556 * New command line options
3558 --init-command=FILE, -ix Like --command, -x but execute it
3559 before loading inferior.
3560 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3561 execute it before loading inferior.
3563 *** Changes in GDB 7.4
3565 * GDB now handles ambiguous linespecs more consistently; the existing
3566 FILE:LINE support has been expanded to other types of linespecs. A
3567 breakpoint will now be set on all matching locations in all
3568 inferiors, and locations will be added or removed according to
3571 * GDB now allows you to skip uninteresting functions and files when
3572 stepping with the "skip function" and "skip file" commands.
3574 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3575 and "show remote hardware-watchpoint-length-limit". These allows to
3576 set or show the maximum length limit (in bytes) of a remote
3577 target hardware watchpoint.
3579 This allows e.g. to use "unlimited" hardware watchpoints with the
3580 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3581 watchpoints are slower than real hardware watchpoints but are
3582 significantly faster than gdb software watchpoints.
3586 ** The register_pretty_printer function in module gdb.printing now takes
3587 an optional `replace' argument. If True, the new printer replaces any
3590 ** The "maint set python print-stack on|off" command has been
3591 deprecated and will be deleted in GDB 7.5.
3592 A new command: "set python print-stack none|full|message" has
3593 replaced it. Additionally, the default for "print-stack" is
3594 now "message", which just prints the error message without
3597 ** A prompt substitution hook (prompt_hook) is now available to the
3600 ** A new Python module, gdb.prompt has been added to the GDB Python
3601 modules library. This module provides functionality for
3602 escape sequences in prompts (used by set/show
3603 extended-prompt). These escape sequences are replaced by their
3604 corresponding value.
3606 ** Python commands and convenience-functions located in
3607 'data-directory'/python/gdb/command and
3608 'data-directory'/python/gdb/function are now automatically loaded
3611 ** Blocks now provide four new attributes. global_block and
3612 static_block will return the global and static blocks
3613 respectively. is_static and is_global are boolean attributes
3614 that indicate if the block is one of those two types.
3616 ** Symbols now provide the "type" attribute, the type of the symbol.
3618 ** The "gdb.breakpoint" function has been deprecated in favor of
3621 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3622 of a function. This class is based on the "finish" command
3623 available in the CLI.
3625 ** Type objects for struct and union types now allow access to
3626 the fields using standard Python dictionary (mapping) methods.
3627 For example, "some_type['myfield']" now works, as does
3628 "some_type.items()".
3630 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3633 ** A new function, "deep_items" has been added to the gdb.types
3634 module in the GDB Python modules library. This function returns
3635 an iterator over the fields of a struct or union type. Unlike
3636 the standard Python "iteritems" method, it will recursively traverse
3637 any anonymous fields.
3641 ** "*stopped" events can report several new "reason"s, such as
3644 ** Breakpoint changes are now notified using new async records, like
3645 "=breakpoint-modified".
3647 ** New command -ada-task-info.
3649 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3650 $sdir specifies the default system locations of shared libraries.
3651 $pdir specifies the directory where the libpthread used by the application
3654 GDB no longer looks in $sdir and $pdir after it has searched the directories
3655 mentioned in libthread-db-search-path. If you want to search those
3656 directories, they must be specified in libthread-db-search-path.
3657 The default value of libthread-db-search-path on GNU/Linux and Solaris
3658 systems is now "$sdir:$pdir".
3660 $pdir is not supported by gdbserver, it is currently ignored.
3661 $sdir is supported by gdbserver.
3663 * New configure option --with-iconv-bin.
3664 When using the internationalization support like the one in the GNU C
3665 library, GDB will invoke the "iconv" program to get a list of supported
3666 character sets. If this program lives in a non-standard location, one can
3667 use this option to specify where to find it.
3669 * When natively debugging programs on PowerPC BookE processors running
3670 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3671 watchpoints, which specify a mask in addition to an address to watch.
3672 The mask specifies that some bits of an address (the bits which are
3673 reset in the mask) should be ignored when matching the address accessed
3674 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3675 section in the user manual for more details.
3677 * The new option --once causes GDBserver to stop listening for connections once
3678 the first connection is made. The listening port used by GDBserver will
3679 become available after that.
3681 * New commands "info macros" and "alias" have been added.
3683 * New function parameters suffix @entry specifies value of function parameter
3684 at the time the function got called. Entry values are available only since
3690 "!" is now an alias of the "shell" command.
3691 Note that no space is needed between "!" and SHELL COMMAND.
3695 watch EXPRESSION mask MASK_VALUE
3696 The watch command now supports the mask argument which allows creation
3697 of masked watchpoints, if the current architecture supports this feature.
3699 info auto-load-scripts [REGEXP]
3700 This command was formerly named "maintenance print section-scripts".
3701 It is now generally useful and is no longer a maintenance-only command.
3703 info macro [-all] [--] MACRO
3704 The info macro command has new options `-all' and `--'. The first for
3705 printing all definitions of a macro. The second for explicitly specifying
3706 the end of arguments and the beginning of the macro name in case the macro
3707 name starts with a hyphen.
3709 collect[/s] EXPRESSIONS
3710 The tracepoint collect command now takes an optional modifier "/s"
3711 that directs it to dereference pointer-to-character types and
3712 collect the bytes of memory up to a zero byte. The behavior is
3713 similar to what you see when you use the regular print command on a
3714 string. An optional integer following the "/s" sets a bound on the
3715 number of bytes that will be collected.
3718 The trace start command now interprets any supplied arguments as a
3719 note to be recorded with the trace run, with an effect similar to
3720 setting the variable trace-notes.
3723 The trace stop command now interprets any arguments as a note to be
3724 mentioned along with the tstatus report that the trace was stopped
3725 with a command. The effect is similar to setting the variable
3728 * Tracepoints can now be enabled and disabled at any time after a trace
3729 experiment has been started using the standard "enable" and "disable"
3730 commands. It is now possible to start a trace experiment with no enabled
3731 tracepoints; GDB will display a warning, but will allow the experiment to
3732 begin, assuming that tracepoints will be enabled as needed while the trace
3735 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3736 locations with 4-byte instructions, when they were previously
3737 limited to locations with instructions of 5 bytes or longer.
3741 set debug dwarf2-read
3742 show debug dwarf2-read
3743 Turns on or off display of debugging messages related to reading
3744 DWARF debug info. The default is off.
3746 set debug symtab-create
3747 show debug symtab-create
3748 Turns on or off display of debugging messages related to symbol table
3749 creation. The default is off.
3752 show extended-prompt
3753 Set the GDB prompt, and allow escape sequences to be inserted to
3754 display miscellaneous information (see 'help set extended-prompt'
3755 for the list of sequences). This prompt (and any information
3756 accessed through the escape sequences) is updated every time the
3757 prompt is displayed.
3759 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3760 show print entry-values
3761 Set printing of frame argument values at function entry. In some cases
3762 GDB can determine the value of function argument which was passed by the
3763 function caller, even if the value was modified inside the called function.
3765 set debug entry-values
3766 show debug entry-values
3767 Control display of debugging info for determining frame argument values at
3768 function entry and virtual tail call frames.
3770 set basenames-may-differ
3771 show basenames-may-differ
3772 Set whether a source file may have multiple base names.
3773 (A "base name" is the name of a file with the directory part removed.
3774 Example: The base name of "/home/user/hello.c" is "hello.c".)
3775 If set, GDB will canonicalize file names (e.g., expand symlinks)
3776 before comparing them. Canonicalization is an expensive operation,
3777 but it allows the same file be known by more than one base name.
3778 If not set (the default), all source files are assumed to have just
3779 one base name, and gdb will do file name comparisons more efficiently.
3785 Set a user name and notes for the current and any future trace runs.
3786 This is useful for long-running and/or disconnected traces, to
3787 inform others (or yourself) as to who is running the trace, supply
3788 contact information, or otherwise explain what is going on.
3790 set trace-stop-notes
3791 show trace-stop-notes
3792 Set a note attached to the trace run, that is displayed when the
3793 trace has been stopped by a tstop command. This is useful for
3794 instance as an explanation, if you are stopping a trace run that was
3795 started by someone else.
3797 * New remote packets
3801 Dynamically enable a tracepoint in a started trace experiment.
3805 Dynamically disable a tracepoint in a started trace experiment.
3809 Set the user and notes of the trace run.
3813 Query the current status of a tracepoint.
3817 Query the minimum length of instruction at which a fast tracepoint may
3820 * Dcache size (number of lines) and line-size are now runtime-configurable
3821 via "set dcache line" and "set dcache line-size" commands.
3825 Texas Instruments TMS320C6x tic6x-*-*
3829 Renesas RL78 rl78-*-elf
3831 *** Changes in GDB 7.3.1
3833 * The build failure for NetBSD and OpenBSD targets have now been fixed.
3835 *** Changes in GDB 7.3
3837 * GDB has a new command: "thread find [REGEXP]".
3838 It finds the thread id whose name, target id, or thread extra info
3839 matches the given regular expression.
3841 * The "catch syscall" command now works on mips*-linux* targets.
3843 * The -data-disassemble MI command now supports modes 2 and 3 for
3844 dumping the instruction opcodes.
3846 * New command line options
3848 -data-directory DIR Specify DIR as the "data-directory".
3849 This is mostly for testing purposes.
3851 * The "maint set python auto-load on|off" command has been renamed to
3852 "set auto-load-scripts on|off".
3854 * GDB has a new command: "set directories".
3855 It is like the "dir" command except that it replaces the
3856 source path list instead of augmenting it.
3858 * GDB now understands thread names.
3860 On GNU/Linux, "info threads" will display the thread name as set by
3861 prctl or pthread_setname_np.
3863 There is also a new command, "thread name", which can be used to
3864 assign a name internally for GDB to display.
3867 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
3868 has been integrated into GDB.
3872 ** The function gdb.Write now accepts an optional keyword 'stream'.
3873 This keyword, when provided, will direct the output to either
3874 stdout, stderr, or GDB's logging output.
3876 ** Parameters can now be be sub-classed in Python, and in particular
3877 you may implement the get_set_doc and get_show_doc functions.
3878 This improves how Parameter set/show documentation is processed
3879 and allows for more dynamic content.
3881 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
3882 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
3883 have an is_valid method.
3885 ** Breakpoints can now be sub-classed in Python, and in particular
3886 you may implement a 'stop' function that is executed each time
3887 the inferior reaches that breakpoint.
3889 ** New function gdb.lookup_global_symbol looks up a global symbol.
3891 ** GDB values in Python are now callable if the value represents a
3892 function. For example, if 'some_value' represents a function that
3893 takes two integer parameters and returns a value, you can call
3894 that function like so:
3896 result = some_value (10,20)
3898 ** Module gdb.types has been added.
3899 It contains a collection of utilities for working with gdb.Types objects:
3900 get_basic_type, has_field, make_enum_dict.
3902 ** Module gdb.printing has been added.
3903 It contains utilities for writing and registering pretty-printers.
3904 New classes: PrettyPrinter, SubPrettyPrinter,
3905 RegexpCollectionPrettyPrinter.
3906 New function: register_pretty_printer.
3908 ** New commands "info pretty-printers", "enable pretty-printer" and
3909 "disable pretty-printer" have been added.
3911 ** gdb.parameter("directories") is now available.
3913 ** New function gdb.newest_frame returns the newest frame in the
3916 ** The gdb.InferiorThread class has a new "name" attribute. This
3917 holds the thread's name.
3919 ** Python Support for Inferior events.
3920 Python scripts can add observers to be notified of events
3921 occurring in the process being debugged.
3922 The following events are currently supported:
3923 - gdb.events.cont Continue event.
3924 - gdb.events.exited Inferior exited event.
3925 - gdb.events.stop Signal received, and Breakpoint hit events.
3929 ** GDB now puts template parameters in scope when debugging in an
3930 instantiation. For example, if you have:
3932 template<int X> int func (void) { return X; }
3934 then if you step into func<5>, "print X" will show "5". This
3935 feature requires proper debuginfo support from the compiler; it
3936 was added to GCC 4.5.
3938 ** The motion commands "next", "finish", "until", and "advance" now
3939 work better when exceptions are thrown. In particular, GDB will
3940 no longer lose control of the inferior; instead, the GDB will
3941 stop the inferior at the point at which the exception is caught.
3942 This functionality requires a change in the exception handling
3943 code that was introduced in GCC 4.5.
3945 * GDB now follows GCC's rules on accessing volatile objects when
3946 reading or writing target state during expression evaluation.
3947 One notable difference to prior behavior is that "print x = 0"
3948 no longer generates a read of x; the value of the assignment is
3949 now always taken directly from the value being assigned.
3951 * GDB now has some support for using labels in the program's source in
3952 linespecs. For instance, you can use "advance label" to continue
3953 execution to a label.
3955 * GDB now has support for reading and writing a new .gdb_index
3956 section. This section holds a fast index of DWARF debugging
3957 information and can be used to greatly speed up GDB startup and
3958 operation. See the documentation for `save gdb-index' for details.
3960 * The "watch" command now accepts an optional "-location" argument.
3961 When used, this causes GDB to watch the memory referred to by the
3962 expression. Such a watchpoint is never deleted due to it going out
3965 * GDB now supports thread debugging of core dumps on GNU/Linux.
3967 GDB now activates thread debugging using the libthread_db library
3968 when debugging GNU/Linux core dumps, similarly to when debugging
3969 live processes. As a result, when debugging a core dump file, GDB
3970 is now able to display pthread_t ids of threads. For example, "info
3971 threads" shows the same output as when debugging the process when it
3972 was live. In earlier releases, you'd see something like this:
3975 * 1 LWP 6780 main () at main.c:10
3977 While now you see this:
3980 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
3982 It is also now possible to inspect TLS variables when debugging core
3985 When debugging a core dump generated on a machine other than the one
3986 used to run GDB, you may need to point GDB at the correct
3987 libthread_db library with the "set libthread-db-search-path"
3988 command. See the user manual for more details on this command.
3990 * When natively debugging programs on PowerPC BookE processors running
3991 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
3992 which stop execution of the inferior whenever it executes an instruction
3993 at any address within the specified range. See the "PowerPC Embedded"
3994 section in the user manual for more details.
3996 * New features in the GDB remote stub, GDBserver
3998 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
3999 and i686 LynxOS (version 5.x).
4001 ** GDBserver is now supported on Blackfin Linux.
4003 * New native configurations
4005 ia64 HP-UX ia64-*-hpux*
4009 Analog Devices, Inc. Blackfin Processor bfin-*
4011 * Ada task switching is now supported on sparc-elf targets when
4012 debugging a program using the Ravenscar Profile. For more information,
4013 see the "Tasking Support when using the Ravenscar Profile" section
4014 in the GDB user manual.
4016 * Guile support was removed.
4018 * New features in the GNU simulator
4020 ** The --map-info flag lists all known core mappings.
4022 ** CFI flashes may be simulated via the "cfi" device.
4024 *** Changes in GDB 7.2
4026 * Shared library support for remote targets by default
4028 When GDB is configured for a generic, non-OS specific target, like
4029 for example, --target=arm-eabi or one of the many *-*-elf targets,
4030 GDB now queries remote stubs for loaded shared libraries using the
4031 `qXfer:libraries:read' packet. Previously, shared library support
4032 was always disabled for such configurations.
4036 ** Argument Dependent Lookup (ADL)
4038 In C++ ADL lookup directs function search to the namespaces of its
4039 arguments even if the namespace has not been imported.
4049 Here the compiler will search for `foo' in the namespace of 'b'
4050 and find A::foo. GDB now supports this. This construct is commonly
4051 used in the Standard Template Library for operators.
4053 ** Improved User Defined Operator Support
4055 In addition to member operators, GDB now supports lookup of operators
4056 defined in a namespace and imported with a `using' directive, operators
4057 defined in the global scope, operators imported implicitly from an
4058 anonymous namespace, and the ADL operators mentioned in the previous
4060 GDB now also supports proper overload resolution for all the previously
4061 mentioned flavors of operators.
4063 ** static const class members
4065 Printing of static const class members that are initialized in the
4066 class definition has been fixed.
4068 * Windows Thread Information Block access.
4070 On Windows targets, GDB now supports displaying the Windows Thread
4071 Information Block (TIB) structure. This structure is visible either
4072 by using the new command `info w32 thread-information-block' or, by
4073 dereferencing the new convenience variable named `$_tlb', a
4074 thread-specific pointer to the TIB. This feature is also supported
4075 when remote debugging using GDBserver.
4077 * Static tracepoints
4079 Static tracepoints are calls in the user program into a tracing
4080 library. One such library is a port of the LTTng kernel tracer to
4081 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4082 When debugging with GDBserver, GDB now supports combining the GDB
4083 tracepoint machinery with such libraries. For example: the user can
4084 use GDB to probe a static tracepoint marker (a call from the user
4085 program into the tracing library) with the new "strace" command (see
4086 "New commands" below). This creates a "static tracepoint" in the
4087 breakpoint list, that can be manipulated with the same feature set
4088 as fast and regular tracepoints. E.g., collect registers, local and
4089 global variables, collect trace state variables, and define
4090 tracepoint conditions. In addition, the user can collect extra
4091 static tracepoint marker specific data, by collecting the new
4092 $_sdata internal variable. When analyzing the trace buffer, you can
4093 inspect $_sdata like any other variable available to GDB. For more
4094 information, see the "Tracepoints" chapter in GDB user manual. New
4095 remote packets have been defined to support static tracepoints, see
4096 the "New remote packets" section below.
4098 * Better reconstruction of tracepoints after disconnected tracing
4100 GDB will attempt to download the original source form of tracepoint
4101 definitions when starting a trace run, and then will upload these
4102 upon reconnection to the target, resulting in a more accurate
4103 reconstruction of the tracepoints that are in use on the target.
4107 You can now exercise direct control over the ways that GDB can
4108 affect your program. For instance, you can disallow the setting of
4109 breakpoints, so that the program can run continuously (assuming
4110 non-stop mode). In addition, the "observer" variable is available
4111 to switch all of the different controls; in observer mode, GDB
4112 cannot affect the target's behavior at all, which is useful for
4113 tasks like diagnosing live systems in the field.
4115 * The new convenience variable $_thread holds the number of the
4118 * New remote packets
4122 Return the address of the Windows Thread Information Block of a given thread.
4126 In response to several of the tracepoint packets, the target may now
4127 also respond with a number of intermediate `qRelocInsn' request
4128 packets before the final result packet, to have GDB handle
4129 relocating an instruction to execute at a different address. This
4130 is particularly useful for stubs that support fast tracepoints. GDB
4131 reports support for this feature in the qSupported packet.
4135 List static tracepoint markers in the target program.
4139 List static tracepoint markers at a given address in the target
4142 qXfer:statictrace:read
4144 Read the static trace data collected (by a `collect $_sdata'
4145 tracepoint action). The remote stub reports support for this packet
4146 to gdb's qSupported query.
4150 Send the current settings of GDB's permission flags.
4154 Send part of the source (textual) form of a tracepoint definition,
4155 which includes location, conditional, and action list.
4157 * The source command now accepts a -s option to force searching for the
4158 script in the source search path even if the script name specifies
4161 * New features in the GDB remote stub, GDBserver
4163 - GDBserver now support tracepoints (including fast tracepoints, and
4164 static tracepoints). The feature is currently supported by the
4165 i386-linux and amd64-linux builds. See the "Tracepoints support
4166 in gdbserver" section in the manual for more information.
4168 GDBserver JIT compiles the tracepoint's conditional agent
4169 expression bytecode into native code whenever possible for low
4170 overhead dynamic tracepoints conditionals. For such tracepoints,
4171 an expression that examines program state is evaluated when the
4172 tracepoint is reached, in order to determine whether to capture
4173 trace data. If the condition is simple and false, processing the
4174 tracepoint finishes very quickly and no data is gathered.
4176 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4177 for static tracepoints support.
4179 - GDBserver now supports x86_64 Windows 64-bit debugging.
4181 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4182 it understands register description.
4184 * The --batch flag now disables pagination and queries.
4186 * X86 general purpose registers
4188 GDB now supports reading/writing byte, word and double-word x86
4189 general purpose registers directly. This means you can use, say,
4190 $ah or $ax to refer, respectively, to the byte register AH and
4191 16-bit word register AX that are actually portions of the 32-bit
4192 register EAX or 64-bit register RAX.
4194 * The `commands' command now accepts a range of breakpoints to modify.
4195 A plain `commands' following a command that creates multiple
4196 breakpoints affects all the breakpoints set by that command. This
4197 applies to breakpoints set by `rbreak', and also applies when a
4198 single `break' command creates multiple breakpoints (e.g.,
4199 breakpoints on overloaded c++ functions).
4201 * The `rbreak' command now accepts a filename specification as part of
4202 its argument, limiting the functions selected by the regex to those
4203 in the specified file.
4205 * Support for remote debugging Windows and SymbianOS shared libraries
4206 from Unix hosts has been improved. Non Windows GDB builds now can
4207 understand target reported file names that follow MS-DOS based file
4208 system semantics, such as file names that include drive letters and
4209 use the backslash character as directory separator. This makes it
4210 possible to transparently use the "set sysroot" and "set
4211 solib-search-path" on Unix hosts to point as host copies of the
4212 target's shared libraries. See the new command "set
4213 target-file-system-kind" described below, and the "Commands to
4214 specify files" section in the user manual for more information.
4218 eval template, expressions...
4219 Convert the values of one or more expressions under the control
4220 of the string template to a command line, and call it.
4222 set target-file-system-kind unix|dos-based|auto
4223 show target-file-system-kind
4224 Set or show the assumed file system kind for target reported file
4227 save breakpoints <filename>
4228 Save all current breakpoint definitions to a file suitable for use
4229 in a later debugging session. To read the saved breakpoint
4230 definitions, use the `source' command.
4232 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4235 info static-tracepoint-markers
4236 Display information about static tracepoint markers in the target.
4238 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4239 Define a static tracepoint by probing a marker at the given
4240 function, line, address, or marker ID.
4244 Enable and disable observer mode.
4246 set may-write-registers on|off
4247 set may-write-memory on|off
4248 set may-insert-breakpoints on|off
4249 set may-insert-tracepoints on|off
4250 set may-insert-fast-tracepoints on|off
4251 set may-interrupt on|off
4252 Set individual permissions for GDB effects on the target. Note that
4253 some of these settings can have undesirable or surprising
4254 consequences, particularly when changed in the middle of a session.
4255 For instance, disabling the writing of memory can prevent
4256 breakpoints from being inserted, cause single-stepping to fail, or
4257 even crash your program, if you disable after breakpoints have been
4258 inserted. However, GDB should not crash.
4260 set record memory-query on|off
4261 show record memory-query
4262 Control whether to stop the inferior if memory changes caused
4263 by an instruction cannot be recorded.
4268 The disassemble command now supports "start,+length" form of two arguments.
4272 ** GDB now provides a new directory location, called the python directory,
4273 where Python scripts written for GDB can be installed. The location
4274 of that directory is <data-directory>/python, where <data-directory>
4275 is the GDB data directory. For more details, see section `Scripting
4276 GDB using Python' in the manual.
4278 ** The GDB Python API now has access to breakpoints, symbols, symbol
4279 tables, program spaces, inferiors, threads and frame's code blocks.
4280 Additionally, GDB Parameters can now be created from the API, and
4281 manipulated via set/show in the CLI.
4283 ** New functions gdb.target_charset, gdb.target_wide_charset,
4284 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4286 ** New exception gdb.GdbError.
4288 ** Pretty-printers are now also looked up in the current program space.
4290 ** Pretty-printers can now be individually enabled and disabled.
4292 ** GDB now looks for names of Python scripts to auto-load in a
4293 special section named `.debug_gdb_scripts', in addition to looking
4294 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4296 * Tracepoint actions were unified with breakpoint commands. In particular,
4297 there are no longer differences in "info break" output for breakpoints and
4298 tracepoints and the "commands" command can be used for both tracepoints and
4299 regular breakpoints.
4303 ARM Symbian arm*-*-symbianelf*
4305 * D language support.
4306 GDB now supports debugging programs written in the D programming
4309 * GDB now supports the extended ptrace interface for PowerPC which is
4310 available since Linux kernel version 2.6.34. This automatically enables
4311 any hardware breakpoints and additional hardware watchpoints available in
4312 the processor. The old ptrace interface exposes just one hardware
4313 watchpoint and no hardware breakpoints.
4315 * GDB is now able to use the Data Value Compare (DVC) register available on
4316 embedded PowerPC processors to implement in hardware simple watchpoint
4317 conditions of the form:
4319 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4321 This works in native GDB running on Linux kernels with the extended ptrace
4322 interface mentioned above.
4324 *** Changes in GDB 7.1
4328 ** Namespace Support
4330 GDB now supports importing of namespaces in C++. This enables the
4331 user to inspect variables from imported namespaces. Support for
4332 namepace aliasing has also been added. So, if a namespace is
4333 aliased in the current scope (e.g. namepace C=A; ) the user can
4334 print variables using the alias (e.g. (gdb) print C::x).
4338 All known bugs relating to the printing of virtual base class were
4339 fixed. It is now possible to call overloaded static methods using a
4344 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4345 and reinterpret_cast<> are now handled by the C++ expression parser.
4349 Xilinx MicroBlaze microblaze-*-*
4354 Xilinx MicroBlaze microblaze
4357 * Multi-program debugging.
4359 GDB now has support for multi-program (a.k.a. multi-executable or
4360 multi-exec) debugging. This allows for debugging multiple inferiors
4361 simultaneously each running a different program under the same GDB
4362 session. See "Debugging Multiple Inferiors and Programs" in the
4363 manual for more information. This implied some user visible changes
4364 in the multi-inferior support. For example, "info inferiors" now
4365 lists inferiors that are not running yet or that have exited
4366 already. See also "New commands" and "New options" below.
4368 * New tracing features
4370 GDB's tracepoint facility now includes several new features:
4372 ** Trace state variables
4374 GDB tracepoints now include support for trace state variables, which
4375 are variables managed by the target agent during a tracing
4376 experiment. They are useful for tracepoints that trigger each
4377 other, so for instance one tracepoint can count hits in a variable,
4378 and then a second tracepoint has a condition that is true when the
4379 count reaches a particular value. Trace state variables share the
4380 $-syntax of GDB convenience variables, and can appear in both
4381 tracepoint actions and condition expressions. Use the "tvariable"
4382 command to create, and "info tvariables" to view; see "Trace State
4383 Variables" in the manual for more detail.
4387 GDB now includes an option for defining fast tracepoints, which
4388 targets may implement more efficiently, such as by installing a jump
4389 into the target agent rather than a trap instruction. The resulting
4390 speedup can be by two orders of magnitude or more, although the
4391 tradeoff is that some program locations on some target architectures
4392 might not allow fast tracepoint installation, for instance if the
4393 instruction to be replaced is shorter than the jump. To request a
4394 fast tracepoint, use the "ftrace" command, with syntax identical to
4395 the regular trace command.
4397 ** Disconnected tracing
4399 It is now possible to detach GDB from the target while it is running
4400 a trace experiment, then reconnect later to see how the experiment
4401 is going. In addition, a new variable disconnected-tracing lets you
4402 tell the target agent whether to continue running a trace if the
4403 connection is lost unexpectedly.
4407 GDB now has the ability to save the trace buffer into a file, and
4408 then use that file as a target, similarly to you can do with
4409 corefiles. You can select trace frames, print data that was
4410 collected in them, and use tstatus to display the state of the
4411 tracing run at the moment that it was saved. To create a trace
4412 file, use "tsave <filename>", and to use it, do "target tfile
4415 ** Circular trace buffer
4417 You can ask the target agent to handle the trace buffer as a
4418 circular buffer, discarding the oldest trace frames to make room for
4419 newer ones, by setting circular-trace-buffer to on. This feature may
4420 not be available for all target agents.
4425 The disassemble command, when invoked with two arguments, now requires
4426 the arguments to be comma-separated.
4429 The info variables command now displays variable definitions. Files
4430 which only declare a variable are not shown.
4433 The source command is now capable of sourcing Python scripts.
4434 This feature is dependent on the debugger being build with Python
4437 Related to this enhancement is also the introduction of a new command
4438 "set script-extension" (see below).
4440 * New commands (for set/show, see "New options" below)
4442 record save [<FILENAME>]
4443 Save a file (in core file format) containing the process record
4444 execution log for replay debugging at a later time.
4446 record restore <FILENAME>
4447 Restore the process record execution log that was saved at an
4448 earlier time, for replay debugging.
4450 add-inferior [-copies <N>] [-exec <FILENAME>]
4453 clone-inferior [-copies <N>] [ID]
4454 Make a new inferior ready to execute the same program another
4455 inferior has loaded.
4460 maint info program-spaces
4461 List the program spaces loaded into GDB.
4463 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4464 show remote interrupt-sequence
4465 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4466 as the sequence to the remote target in order to interrupt the execution.
4467 Ctrl-C is a default. Some system prefers BREAK which is high level of
4468 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4469 Magic SysRq g. It is BREAK signal and character 'g'.
4471 set remote interrupt-on-connect [on | off]
4472 show remote interrupt-on-connect
4473 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4474 remote target when gdb connects to it. This is needed when you debug
4477 set remotebreak [on | off]
4479 Deprecated. Use "set/show remote interrupt-sequence" instead.
4481 tvariable $NAME [ = EXP ]
4482 Create or modify a trace state variable.
4485 List trace state variables and their values.
4487 delete tvariable $NAME ...
4488 Delete one or more trace state variables.
4491 Evaluate the given expressions without collecting anything into the
4492 trace buffer. (Valid in tracepoint actions only.)
4494 ftrace FN / FILE:LINE / *ADDR
4495 Define a fast tracepoint at the given function, line, or address.
4497 * New expression syntax
4499 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4500 GDB now parses 0b101010 identically with 42.
4504 set follow-exec-mode new|same
4505 show follow-exec-mode
4506 Control whether GDB reuses the same inferior across an exec call or
4507 creates a new one. This is useful to be able to restart the old
4508 executable after the inferior having done an exec call.
4510 set default-collect EXPR, ...
4511 show default-collect
4512 Define a list of expressions to be collected at each tracepoint.
4513 This is a useful way to ensure essential items are not overlooked,
4514 such as registers or a critical global variable.
4516 set disconnected-tracing
4517 show disconnected-tracing
4518 If set to 1, the target is instructed to continue tracing if it
4519 loses its connection to GDB. If 0, the target is to stop tracing
4522 set circular-trace-buffer
4523 show circular-trace-buffer
4524 If set to on, the target is instructed to use a circular trace buffer
4525 and discard the oldest trace frames instead of stopping the trace due
4526 to a full trace buffer. If set to off, the trace stops when the buffer
4527 fills up. Some targets may not support this.
4529 set script-extension off|soft|strict
4530 show script-extension
4531 If set to "off", the debugger does not perform any script language
4532 recognition, and all sourced files are assumed to be GDB scripts.
4533 If set to "soft" (the default), files are sourced according to
4534 filename extension, falling back to GDB scripts if the first
4536 If set to "strict", files are sourced according to filename extension.
4538 set ada trust-PAD-over-XVS on|off
4539 show ada trust-PAD-over-XVS
4540 If off, activate a workaround against a bug in the debugging information
4541 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4542 the GCC sources for more information about the GNAT encoding and
4543 PAD types in particular). It is always safe to set this option to
4544 off, but this introduces a slight performance penalty. The default
4547 * Python API Improvements
4549 ** GDB provides the new class gdb.LazyString. This is useful in
4550 some pretty-printing cases. The new method gdb.Value.lazy_string
4551 provides a simple way to create objects of this type.
4553 ** The fields returned by gdb.Type.fields now have an
4554 `is_base_class' attribute.
4556 ** The new method gdb.Type.range returns the range of an array type.
4558 ** The new method gdb.parse_and_eval can be used to parse and
4559 evaluate an expression.
4561 * New remote packets
4564 Define a trace state variable.
4567 Get the current value of a trace state variable.
4570 Set desired tracing behavior upon disconnection.
4573 Set the trace buffer to be linear or circular.
4576 Get data about the tracepoints currently in use.
4580 Process record now works correctly with hardware watchpoints.
4582 Multiple bug fixes have been made to the mips-irix port, making it
4583 much more reliable. In particular:
4584 - Debugging threaded applications is now possible again. Previously,
4585 GDB would hang while starting the program, or while waiting for
4586 the program to stop at a breakpoint.
4587 - Attaching to a running process no longer hangs.
4588 - An error occurring while loading a core file has been fixed.
4589 - Changing the value of the PC register now works again. This fixes
4590 problems observed when using the "jump" command, or when calling
4591 a function from GDB, or even when assigning a new value to $pc.
4592 - With the "finish" and "return" commands, the return value for functions
4593 returning a small array is now correctly printed.
4594 - It is now possible to break on shared library code which gets executed
4595 during a shared library init phase (code executed while executing
4596 their .init section). Previously, the breakpoint would have no effect.
4597 - GDB is now able to backtrace through the signal handler for
4598 non-threaded programs.
4600 PIE (Position Independent Executable) programs debugging is now supported.
4601 This includes debugging execution of PIC (Position Independent Code) shared
4602 libraries although for that, it should be possible to run such libraries as an
4605 *** Changes in GDB 7.0
4607 * GDB now has an interface for JIT compilation. Applications that
4608 dynamically generate code can create symbol files in memory and register
4609 them with GDB. For users, the feature should work transparently, and
4610 for JIT developers, the interface is documented in the GDB manual in the
4611 "JIT Compilation Interface" chapter.
4613 * Tracepoints may now be conditional. The syntax is as for
4614 breakpoints; either an "if" clause appended to the "trace" command,
4615 or the "condition" command is available. GDB sends the condition to
4616 the target for evaluation using the same bytecode format as is used
4617 for tracepoint actions.
4619 * The disassemble command now supports: an optional /r modifier, print the
4620 raw instructions in hex as well as in symbolic form, and an optional /m
4621 modifier to print mixed source+assembly.
4623 * Process record and replay
4625 In a architecture environment that supports ``process record and
4626 replay'', ``process record and replay'' target can record a log of
4627 the process execution, and replay it with both forward and reverse
4630 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4631 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4632 set execution-direction {forward|reverse}, for targets that support
4635 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4636 feature is available with a native GDB running on kernel version
4639 * GDB now has support for multi-byte and wide character sets on the
4640 target. Strings whose character type is wchar_t, char16_t, or
4641 char32_t are now correctly printed. GDB supports wide- and unicode-
4642 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4643 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4644 `printf'. This feature requires iconv to work properly; if your
4645 system does not have a working iconv, GDB can use GNU libiconv. See
4646 the installation instructions for more information.
4648 * GDB now supports automatic retrieval of shared library files from
4649 remote targets. To use this feature, specify a system root that begins
4650 with the `remote:' prefix, either via the `set sysroot' command or via
4651 the `--with-sysroot' configure-time option.
4653 * "info sharedlibrary" now takes an optional regex of libraries to show,
4654 and it now reports if a shared library has no debugging information.
4656 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4657 now complete on file names.
4659 * When completing in expressions, gdb will attempt to limit
4660 completions to allowable structure or union fields, where appropriate.
4661 For instance, consider:
4663 # struct example { int f1; double f2; };
4664 # struct example variable;
4667 If the user types TAB at the end of this command line, the available
4668 completions will be "f1" and "f2".
4670 * Inlined functions are now supported. They show up in backtraces, and
4671 the "step", "next", and "finish" commands handle them automatically.
4673 * GDB now supports the token-splicing (##) and stringification (#)
4674 operators when expanding macros. It also supports variable-arity
4677 * GDB now supports inspecting extra signal information, exported by
4678 the new $_siginfo convenience variable. The feature is currently
4679 implemented on linux ARM, i386 and amd64.
4681 * GDB can now display the VFP floating point registers and NEON vector
4682 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4683 can provide these registers (requires Linux 2.6.30 or later). Remote
4684 and simulator targets may also provide them.
4686 * New remote packets
4689 Search memory for a sequence of bytes.
4692 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4693 operation over reliable transport links. Use of this packet is
4694 controlled by the `set remote noack-packet' command.
4697 Kill the process with the specified process ID. Use this in preference
4698 to `k' when multiprocess protocol extensions are supported.
4701 Obtains additional operating system information
4705 Read or write additional signal information.
4707 * Removed remote protocol undocumented extension
4709 An undocumented extension to the remote protocol's `S' stop reply
4710 packet that permitted the stub to pass a process id was removed.
4711 Remote servers should use the `T' stop reply packet instead.
4713 * GDB now supports multiple function calling conventions according to the
4714 DWARF-2 DW_AT_calling_convention function attribute.
4716 * The SH target utilizes the aforementioned change to distinguish between gcc
4717 and Renesas calling convention. It also adds the new CLI commands
4718 `set/show sh calling-convention'.
4720 * GDB can now read compressed debug sections, as produced by GNU gold
4721 with the --compress-debug-sections=zlib flag.
4723 * 64-bit core files are now supported on AIX.
4725 * Thread switching is now supported on Tru64.
4727 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4728 which will be allocated using malloc later in program execution.
4730 * The qXfer:libraries:read remote protocol packet now allows passing a
4731 list of section offsets.
4733 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4734 conditions handling signals delivered during attach or thread creation
4735 have also been fixed.
4737 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4738 From the user's standpoint, all unqualified instances of True and False
4739 are treated as the standard definitions, regardless of context.
4741 * GDB now parses C++ symbol and type names more flexibly. For
4744 template<typename T> class C { };
4747 GDB will now correctly handle all of:
4749 ptype C<char const *>
4750 ptype C<char const*>
4751 ptype C<const char *>
4752 ptype C<const char*>
4754 * New features in the GDB remote stub, gdbserver
4756 - The "--wrapper" command-line argument tells gdbserver to use a
4757 wrapper program to launch programs for debugging.
4759 - On PowerPC and S/390 targets, it is now possible to use a single
4760 gdbserver executable to debug both 32-bit and 64-bit programs.
4761 (This requires gdbserver itself to be built as a 64-bit executable.)
4763 - gdbserver uses the new noack protocol mode for TCP connections to
4764 reduce communications latency, if also supported and enabled in GDB.
4766 - Support for the sparc64-linux-gnu target is now included in
4769 - The amd64-linux build of gdbserver now supports debugging both
4770 32-bit and 64-bit programs.
4772 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
4773 now support hardware watchpoints, and will use them automatically
4778 GDB now has support for scripting using Python. Whether this is
4779 available is determined at configure time.
4781 New GDB commands can now be written in Python.
4783 * Ada tasking support
4785 Ada tasks can now be inspected in GDB. The following commands have
4789 Print the list of Ada tasks.
4791 Print detailed information about task number N.
4793 Print the task number of the current task.
4795 Switch the context of debugging to task number N.
4797 * Support for user-defined prefixed commands. The "define" command can
4798 add new commands to existing prefixes, e.g. "target".
4800 * Multi-inferior, multi-process debugging.
4802 GDB now has generalized support for multi-inferior debugging. See
4803 "Debugging Multiple Inferiors" in the manual for more information.
4804 Although availability still depends on target support, the command
4805 set is more uniform now. The GNU/Linux specific multi-forks support
4806 has been migrated to this new framework. This implied some user
4807 visible changes; see "New commands" and also "Removed commands"
4810 * Target descriptions can now describe the target OS ABI. See the
4811 "Target Description Format" section in the user manual for more
4814 * Target descriptions can now describe "compatible" architectures
4815 to indicate that the target can execute applications for a different
4816 architecture in addition to those for the main target architecture.
4817 See the "Target Description Format" section in the user manual for
4820 * Multi-architecture debugging.
4822 GDB now includes general supports for debugging applications on
4823 hybrid systems that use more than one single processor architecture
4824 at the same time. Each such hybrid architecture still requires
4825 specific support to be added. The only hybrid architecture supported
4826 in this version of GDB is the Cell Broadband Engine.
4828 * GDB now supports integrated debugging of Cell/B.E. applications that
4829 use both the PPU and SPU architectures. To enable support for hybrid
4830 Cell/B.E. debugging, you need to configure GDB to support both the
4831 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
4832 --enable-targets configure option.
4834 * Non-stop mode debugging.
4836 For some targets, GDB now supports an optional mode of operation in
4837 which you can examine stopped threads while other threads continue
4838 to execute freely. This is referred to as non-stop mode, with the
4839 old mode referred to as all-stop mode. See the "Non-Stop Mode"
4840 section in the user manual for more information.
4842 To be able to support remote non-stop debugging, a remote stub needs
4843 to implement the non-stop mode remote protocol extensions, as
4844 described in the "Remote Non-Stop" section of the user manual. The
4845 GDB remote stub, gdbserver, has been adjusted to support these
4846 extensions on linux targets.
4848 * New commands (for set/show, see "New options" below)
4850 catch syscall [NAME(S) | NUMBER(S)]
4851 Catch system calls. Arguments, which should be names of system
4852 calls or their numbers, mean catch only those syscalls. Without
4853 arguments, every syscall will be caught. When the inferior issues
4854 any of the specified syscalls, GDB will stop and announce the system
4855 call, both when it is called and when its call returns. This
4856 feature is currently available with a native GDB running on the
4857 Linux Kernel, under the following architectures: x86, x86_64,
4858 PowerPC and PowerPC64.
4860 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
4862 Search memory for a sequence of bytes.
4864 maint set python print-stack
4865 maint show python print-stack
4866 Show a stack trace when an error is encountered in a Python script.
4869 Invoke CODE by passing it to the Python interpreter.
4874 These allow macros to be defined, undefined, and listed
4878 Show operating system information about processes.
4881 List the inferiors currently under GDB's control.
4884 Switch focus to inferior number NUM.
4887 Detach from inferior number NUM.
4890 Kill inferior number NUM.
4894 set spu stop-on-load
4895 show spu stop-on-load
4896 Control whether to stop for new SPE threads during Cell/B.E. debugging.
4898 set spu auto-flush-cache
4899 show spu auto-flush-cache
4900 Control whether to automatically flush the software-managed cache
4901 during Cell/B.E. debugging.
4903 set sh calling-convention
4904 show sh calling-convention
4905 Control the calling convention used when calling SH target functions.
4908 show debug timestamp
4909 Control display of timestamps with GDB debugging output.
4911 set disassemble-next-line
4912 show disassemble-next-line
4913 Control display of disassembled source lines or instructions when
4916 set remote noack-packet
4917 show remote noack-packet
4918 Set/show the use of remote protocol QStartNoAckMode packet. See above
4919 under "New remote packets."
4921 set remote query-attached-packet
4922 show remote query-attached-packet
4923 Control use of remote protocol `qAttached' (query-attached) packet.
4925 set remote read-siginfo-object
4926 show remote read-siginfo-object
4927 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
4930 set remote write-siginfo-object
4931 show remote write-siginfo-object
4932 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
4935 set remote reverse-continue
4936 show remote reverse-continue
4937 Control use of remote protocol 'bc' (reverse-continue) packet.
4939 set remote reverse-step
4940 show remote reverse-step
4941 Control use of remote protocol 'bs' (reverse-step) packet.
4943 set displaced-stepping
4944 show displaced-stepping
4945 Control displaced stepping mode. Displaced stepping is a way to
4946 single-step over breakpoints without removing them from the debuggee.
4947 Also known as "out-of-line single-stepping".
4950 show debug displaced
4951 Control display of debugging info for displaced stepping.
4953 maint set internal-error
4954 maint show internal-error
4955 Control what GDB does when an internal error is detected.
4957 maint set internal-warning
4958 maint show internal-warning
4959 Control what GDB does when an internal warning is detected.
4964 Use a wrapper program to launch programs for debugging.
4966 set multiple-symbols (all|ask|cancel)
4967 show multiple-symbols
4968 The value of this variable can be changed to adjust the debugger behavior
4969 when an expression or a breakpoint location contains an ambiguous symbol
4970 name (an overloaded function name, for instance).
4972 set breakpoint always-inserted
4973 show breakpoint always-inserted
4974 Keep breakpoints always inserted in the target, as opposed to inserting
4975 them when resuming the target, and removing them when the target stops.
4976 This option can improve debugger performance on slow remote targets.
4978 set arm fallback-mode (arm|thumb|auto)
4979 show arm fallback-mode
4980 set arm force-mode (arm|thumb|auto)
4982 These commands control how ARM GDB determines whether instructions
4983 are ARM or Thumb. The default for both settings is auto, which uses
4984 the current CPSR value for instructions without symbols; previous
4985 versions of GDB behaved as if "set arm fallback-mode arm".
4987 set disable-randomization
4988 show disable-randomization
4989 Standalone programs run with the virtual address space randomization enabled
4990 by default on some platforms. This option keeps the addresses stable across
4991 multiple debugging sessions.
4995 Control whether other threads are stopped or not when some thread hits
5000 Requests that asynchronous execution is enabled in the target, if available.
5001 In this case, it's possible to resume target in the background, and interact
5002 with GDB while the target is running. "show target-async" displays the
5003 current state of asynchronous execution of the target.
5005 set target-wide-charset
5006 show target-wide-charset
5007 The target-wide-charset is the name of the character set that GDB
5008 uses when printing characters whose type is wchar_t.
5010 set tcp auto-retry (on|off)
5012 set tcp connect-timeout
5013 show tcp connect-timeout
5014 These commands allow GDB to retry failed TCP connections to a remote stub
5015 with a specified timeout period; this is useful if the stub is launched
5016 in parallel with GDB but may not be ready to accept connections immediately.
5018 set libthread-db-search-path
5019 show libthread-db-search-path
5020 Control list of directories which GDB will search for appropriate
5023 set schedule-multiple (on|off)
5024 show schedule-multiple
5025 Allow GDB to resume all threads of all processes or only threads of
5026 the current process.
5030 Use more aggressive caching for accesses to the stack. This improves
5031 performance of remote debugging (particularly backtraces) without
5032 affecting correctness.
5034 set interactive-mode (on|off|auto)
5035 show interactive-mode
5036 Control whether GDB runs in interactive mode (on) or not (off).
5037 When in interactive mode, GDB waits for the user to answer all
5038 queries. Otherwise, GDB does not wait and assumes the default
5039 answer. When set to auto (the default), GDB determines which
5040 mode to use based on the stdin settings.
5045 For program forks, this is replaced by the new more generic `info
5046 inferiors' command. To list checkpoints, you can still use the
5047 `info checkpoints' command, which was an alias for the `info forks'
5051 Replaced by the new `inferior' command. To switch between
5052 checkpoints, you can still use the `restart' command, which was an
5053 alias for the `fork' command.
5056 This is removed, since some targets don't have a notion of
5057 processes. To switch between processes, you can still use the
5058 `inferior' command using GDB's own inferior number.
5061 For program forks, this is replaced by the new more generic `kill
5062 inferior' command. To delete a checkpoint, you can still use the
5063 `delete checkpoint' command, which was an alias for the `delete
5067 For program forks, this is replaced by the new more generic `detach
5068 inferior' command. To detach a checkpoint, you can still use the
5069 `detach checkpoint' command, which was an alias for the `detach
5072 * New native configurations
5074 x86/x86_64 Darwin i[34567]86-*-darwin*
5076 x86_64 MinGW x86_64-*-mingw*
5080 Lattice Mico32 lm32-*
5081 x86 DICOS i[34567]86-*-dicos*
5082 x86_64 DICOS x86_64-*-dicos*
5085 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5086 (mingw32ce) debugging.
5092 These commands were actually not implemented on any target.
5094 *** Changes in GDB 6.8
5096 * New native configurations
5098 NetBSD/hppa hppa*-*netbsd*
5099 Xtensa GNU/Linux xtensa*-*-linux*
5103 NetBSD/hppa hppa*-*-netbsd*
5104 Xtensa GNU/Linux xtensa*-*-linux*
5106 * Change in command line behavior -- corefiles vs. process ids.
5108 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5109 attaching to process NUMBER fails, GDB no longer attempts to open a
5110 core file named NUMBER. Attaching to a program using the -c option
5111 is no longer supported. Instead, use the '-p' or '--pid' options.
5113 * GDB can now be built as a native debugger for debugging Windows x86
5114 (mingw32) Portable Executable (PE) programs.
5116 * Pending breakpoints no longer change their number when their address
5119 * GDB now supports breakpoints with multiple locations,
5120 including breakpoints on C++ constructors, inside C++ templates,
5121 and in inlined functions.
5123 * GDB's ability to debug optimized code has been improved. GDB more
5124 accurately identifies function bodies and lexical blocks that occupy
5125 more than one contiguous range of addresses.
5127 * Target descriptions can now describe registers for PowerPC.
5129 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5130 registers on PowerPC targets.
5132 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5133 targets even when the libthread_db library is not available.
5135 * The GDB remote stub, gdbserver, now supports the new file transfer
5136 commands (remote put, remote get, and remote delete).
5138 * The GDB remote stub, gdbserver, now supports run and attach in
5139 extended-remote mode.
5141 * hppa*64*-*-hpux11* target broken
5142 The debugger is unable to start a program and fails with the following
5143 error: "Error trying to get information about dynamic linker".
5144 The gdb-6.7 release is also affected.
5146 * GDB now supports the --enable-targets= configure option to allow
5147 building a single GDB executable that supports multiple remote
5148 target architectures.
5150 * GDB now supports debugging C and C++ programs which use the
5151 Decimal Floating Point extension. In addition, the PowerPC target
5152 now has a set of pseudo-registers to inspect decimal float values
5153 stored in two consecutive float registers.
5155 * The -break-insert MI command can optionally create pending
5158 * Improved support for debugging Ada
5159 Many improvements to the Ada language support have been made. These
5161 - Better support for Ada2005 interface types
5162 - Improved handling of arrays and slices in general
5163 - Better support for Taft-amendment types
5164 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5166 - Improved command completion in Ada
5169 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5174 set print frame-arguments (all|scalars|none)
5175 show print frame-arguments
5176 The value of this variable can be changed to control which argument
5177 values should be printed by the debugger when displaying a frame.
5182 Transfer files to and from a remote target, and delete remote files.
5189 Transfer files to and from a remote target, and delete remote files.
5191 * New remote packets
5198 Open, close, read, write, and delete files on the remote system.
5201 Attach to an existing process on the remote system, in extended-remote
5205 Run a new process on the remote system, in extended-remote mode.
5207 *** Changes in GDB 6.7
5209 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5210 bfd, libiberty and opcodes, as revealed by static analysis donated by
5211 Coverity, Inc. (http://scan.coverity.com).
5213 * When looking up multiply-defined global symbols, GDB will now prefer the
5214 symbol definition in the current shared library if it was built using the
5215 -Bsymbolic linker option.
5217 * When the Text User Interface (TUI) is not configured, GDB will now
5218 recognize the -tui command-line option and print a message that the TUI
5221 * The GDB remote stub, gdbserver, now has lower overhead for high
5222 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5224 * GDB for MIPS targets now autodetects whether a remote target provides
5225 32-bit or 64-bit register values.
5227 * Support for C++ member pointers has been improved.
5229 * GDB now understands XML target descriptions, which specify the
5230 target's overall architecture. GDB can read a description from
5231 a local file or over the remote serial protocol.
5233 * Vectors of single-byte data use a new integer type which is not
5234 automatically displayed as character or string data.
5236 * The /s format now works with the print command. It displays
5237 arrays of single-byte integers and pointers to single-byte integers
5240 * Target descriptions can now describe target-specific registers,
5241 for architectures which have implemented the support (currently
5242 only ARM, M68K, and MIPS).
5244 * GDB and the GDB remote stub, gdbserver, now support the XScale
5247 * The GDB remote stub, gdbserver, has been updated to support
5248 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5249 has been rewritten to use the standard GDB remote protocol.
5251 * GDB can now step into C++ functions which are called through thunks.
5253 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5255 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5256 layout. It also supports a TextSeg= and DataSeg= response when only
5257 segment base addresses (rather than offsets) are available.
5259 * The /i format now outputs any trailing branch delay slot instructions
5260 immediately following the last instruction within the count specified.
5262 * The GDB remote protocol "T" stop reply packet now supports a
5263 "library" response. Combined with the new "qXfer:libraries:read"
5264 packet, this response allows GDB to debug shared libraries on targets
5265 where the operating system manages the list of loaded libraries (e.g.
5266 Windows and SymbianOS).
5268 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5269 (DLLs) on Windows and Windows CE targets.
5271 * GDB now supports a faster verification that a .debug file matches its binary
5272 according to its build-id signature, if the signature is present.
5278 Enable or disable hardware flow control (RTS/CTS) on the serial port
5279 when debugging using remote targets.
5281 set mem inaccessible-by-default
5282 show mem inaccessible-by-default
5283 If the target supplies a memory map, for instance via the remote
5284 protocol's "qXfer:memory-map:read" packet, setting this variable
5285 prevents GDB from accessing memory outside the memory map. This
5286 is useful for targets with memory mapped registers or which react
5287 badly to accesses of unmapped address space.
5289 set breakpoint auto-hw
5290 show breakpoint auto-hw
5291 If the target supplies a memory map, for instance via the remote
5292 protocol's "qXfer:memory-map:read" packet, setting this variable
5293 lets GDB use hardware breakpoints automatically for memory regions
5294 where it can not use software breakpoints. This covers both the
5295 "break" command and internal breakpoints used for other commands
5296 including "next" and "finish".
5299 catch exception unhandled
5300 Stop the program execution when Ada exceptions are raised.
5303 Stop the program execution when an Ada assertion failed.
5307 Set an alternate system root for target files. This is a more
5308 general version of "set solib-absolute-prefix", which is now
5309 an alias to "set sysroot".
5312 Provide extended SPU facility status information. This set of
5313 commands is available only when debugging the Cell/B.E. SPU
5316 * New native configurations
5318 OpenBSD/sh sh*-*openbsd*
5321 unset tdesc filename
5323 Use the specified local file as an XML target description, and do
5324 not query the target for its built-in description.
5328 OpenBSD/sh sh*-*-openbsd*
5329 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5330 Toshiba Media Processor mep-elf
5332 * New remote packets
5335 Ignore the specified signals; pass them directly to the debugged program
5336 without stopping other threads or reporting them to GDB.
5338 qXfer:features:read:
5339 Read an XML target description from the target, which describes its
5344 Read or write contents of an spufs file on the target system. These
5345 packets are available only on the Cell/B.E. SPU architecture.
5347 qXfer:libraries:read:
5348 Report the loaded shared libraries. Combined with new "T" packet
5349 response, this packet allows GDB to debug shared libraries on
5350 targets where the operating system manages the list of loaded
5351 libraries (e.g. Windows and SymbianOS).
5355 Support for these obsolete configurations has been removed.
5363 i[34567]86-*-lynxos*
5364 i[34567]86-*-netware*
5365 i[34567]86-*-sco3.2v5*
5366 i[34567]86-*-sco3.2v4*
5368 i[34567]86-*-sysv4.2*
5371 i[34567]86-*-unixware2*
5372 i[34567]86-*-unixware*
5381 * Other removed features
5388 Various m68k-only ROM monitors.
5395 Various Renesas ROM monitors and debugging interfaces for SH and
5400 Support for a Macraigor serial interface to on-chip debugging.
5401 GDB does not directly support the newer parallel or USB
5406 A debug information format. The predecessor to DWARF 2 and
5407 DWARF 3, which are still supported.
5409 Support for the HP aCC compiler on HP-UX/PA-RISC
5411 SOM-encapsulated symbolic debugging information, automatic
5412 invocation of pxdb, and the aCC custom C++ ABI. This does not
5413 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5414 with aCC can still be debugged on an assembly level.
5416 MIPS ".pdr" sections
5418 A MIPS-specific format used to describe stack frame layout
5419 in debugging information.
5423 GDB could work with an older version of Guile to debug
5424 the interpreter and Scheme programs running in it.
5426 set mips stack-arg-size
5427 set mips saved-gpreg-size
5429 Use "set mips abi" to control parameter passing for MIPS.
5431 *** Changes in GDB 6.6
5436 Cell Broadband Engine SPU spu-elf
5438 * GDB can now be configured as a cross-debugger targeting native Windows
5439 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5440 running on a Windows system over TCP/IP to debug Windows programs.
5442 * The GDB remote stub, gdbserver, has been updated to support Windows and
5443 Cygwin debugging. Both single-threaded and multi-threaded programs are
5446 * The "set trust-readonly-sections" command works again. This command was
5447 broken in GDB 6.3, 6.4, and 6.5.
5449 * The "load" command now supports writing to flash memory, if the remote
5450 stub provides the required support.
5452 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5453 longer requires symbolic debug information (e.g. DWARF-2).
5458 unset substitute-path
5459 show substitute-path
5460 Manage a list of substitution rules that GDB uses to rewrite the name
5461 of the directories where the sources are located. This can be useful
5462 for instance when the sources were moved to a different location
5463 between compilation and debugging.
5467 Print each CLI command as it is executed. Each command is prefixed with
5468 a number of `+' symbols representing the nesting depth.
5469 The source command now has a `-v' option to enable the same feature.
5473 The ARM Demon monitor support (RDP protocol, "target rdp").
5475 Kernel Object Display, an embedded debugging feature which only worked with
5476 an obsolete version of Cisco IOS.
5478 The 'set download-write-size' and 'show download-write-size' commands.
5480 * New remote packets
5483 Tell a stub about GDB client features, and request remote target features.
5484 The first feature implemented is PacketSize, which allows the target to
5485 specify the size of packets it can handle - to minimize the number of
5486 packets required and improve performance when connected to a remote
5490 Fetch an OS auxilliary vector from the remote stub. This packet is a
5491 more efficient replacement for qPart:auxv:read.
5493 qXfer:memory-map:read:
5494 Fetch a memory map from the remote stub, including information about
5495 RAM, ROM, and flash memory devices.
5500 Erase and program a flash memory device.
5502 * Removed remote packets
5505 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5506 used it, and only gdbserver implemented it.
5508 *** Changes in GDB 6.5
5512 Renesas M32C/M16C m32c-elf
5514 Morpho Technologies ms1 ms1-elf
5518 init-if-undefined Initialize a convenience variable, but
5519 only if it doesn't already have a value.
5521 The following commands are presently only implemented for native GNU/Linux:
5523 checkpoint Save a snapshot of the program state.
5525 restart <n> Return the program state to a
5526 previously saved state.
5528 info checkpoints List currently saved checkpoints.
5530 delete-checkpoint <n> Delete a previously saved checkpoint.
5532 set|show detach-on-fork Tell gdb whether to detach from a newly
5533 forked process, or to keep debugging it.
5535 info forks List forks of the user program that
5536 are available to be debugged.
5538 fork <n> Switch to debugging one of several
5539 forks of the user program that are
5540 available to be debugged.
5542 delete-fork <n> Delete a fork from the list of forks
5543 that are available to be debugged (and
5544 kill the forked process).
5546 detach-fork <n> Delete a fork from the list of forks
5547 that are available to be debugged (and
5548 allow the process to continue).
5552 Morpho Technologies ms2 ms1-elf
5554 * Improved Windows host support
5556 GDB now builds as a cross debugger hosted on i686-mingw32, including
5557 native console support, and remote communications using either
5558 network sockets or serial ports.
5560 * Improved Modula-2 language support
5562 GDB can now print most types in the Modula-2 syntax. This includes:
5563 basic types, set types, record types, enumerated types, range types,
5564 pointer types and ARRAY types. Procedure var parameters are correctly
5565 printed and hexadecimal addresses and character constants are also
5566 written in the Modula-2 syntax. Best results can be obtained by using
5567 GNU Modula-2 together with the -gdwarf-2 command line option.
5571 The ARM rdi-share module.
5573 The Netware NLM debug server.
5575 *** Changes in GDB 6.4
5577 * New native configurations
5579 OpenBSD/arm arm*-*-openbsd*
5580 OpenBSD/mips64 mips64-*-openbsd*
5584 Morpho Technologies ms1 ms1-elf
5586 * New command line options
5588 --batch-silent As for --batch, but totally silent.
5589 --return-child-result The debugger will exist with the same value
5590 the child (debugged) program exited with.
5591 --eval-command COMMAND, -ex COMMAND
5592 Execute a single GDB CLI command. This may be
5593 specified multiple times and in conjunction
5594 with the --command (-x) option.
5596 * Deprecated commands removed
5598 The following commands, that were deprecated in 2000, have been
5602 set|show arm disassembly-flavor set|show arm disassembler
5603 othernames set arm disassembler
5604 set|show remotedebug set|show debug remote
5605 set|show archdebug set|show debug arch
5606 set|show eventdebug set|show debug event
5609 * New BSD user-level threads support
5611 It is now possible to debug programs using the user-level threads
5612 library on OpenBSD and FreeBSD. Currently supported (target)
5615 FreeBSD/amd64 x86_64-*-freebsd*
5616 FreeBSD/i386 i386-*-freebsd*
5617 OpenBSD/i386 i386-*-openbsd*
5619 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5620 are not yet supported.
5622 * New support for Matsushita MN10300 w/sim added
5623 (Work in progress). mn10300-elf.
5625 * REMOVED configurations and files
5627 VxWorks and the XDR protocol *-*-vxworks
5628 Motorola MCORE mcore-*-*
5629 National Semiconductor NS32000 ns32k-*-*
5631 * New "set print array-indexes" command
5633 After turning this setting "on", GDB prints the index of each element
5634 when displaying arrays. The default is "off" to preserve the previous
5637 * VAX floating point support
5639 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5641 * User-defined command support
5643 In addition to using $arg0..$arg9 for argument passing, it is now possible
5644 to use $argc to determine now many arguments have been passed. See the
5645 section on user-defined commands in the user manual for more information.
5647 *** Changes in GDB 6.3:
5649 * New command line option
5651 GDB now accepts -l followed by a number to set the timeout for remote
5654 * GDB works with GCC -feliminate-dwarf2-dups
5656 GDB now supports a more compact representation of DWARF-2 debug
5657 information using DW_FORM_ref_addr references. These are produced
5658 by GCC with the option -feliminate-dwarf2-dups and also by some
5659 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5660 to use -feliminate-dwarf2-dups.
5662 * Internationalization
5664 When supported by the host system, GDB will be built with
5665 internationalization (libintl). The task of marking up the sources is
5666 continued, we're looking forward to our first translation.
5670 Initial support for debugging programs compiled with the GNAT
5671 implementation of the Ada programming language has been integrated
5672 into GDB. In this release, support is limited to expression evaluation.
5674 * New native configurations
5676 GNU/Linux/m32r m32r-*-linux-gnu
5680 GDB's remote protocol now includes support for the 'p' packet. This
5681 packet is used to fetch individual registers from a remote inferior.
5683 * END-OF-LIFE registers[] compatibility module
5685 GDB's internal register infrastructure has been completely rewritten.
5686 The new infrastructure making possible the implementation of key new
5687 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5690 GDB 6.3 will be the last release to include the registers[]
5691 compatibility module that allowed out-of-date configurations to
5692 continue to work. This change directly impacts the following
5702 powerpc bdm protocol
5704 Unless there is activity to revive these configurations, they will be
5705 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5707 * OBSOLETE configurations and files
5709 Configurations that have been declared obsolete in this release have
5710 been commented out. Unless there is activity to revive these
5711 configurations, the next release of GDB will have their sources
5712 permanently REMOVED.
5721 *** Changes in GDB 6.2.1:
5723 * MIPS `break main; run' gave an heuristic-fence-post warning
5725 When attempting to run even a simple program, a warning about
5726 heuristic-fence-post being hit would be reported. This problem has
5729 * MIPS IRIX 'long double' crashed GDB
5731 When examining a long double variable, GDB would get a segmentation
5732 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5733 IRIX long double values).
5737 A bug in the VAX stack code was causing problems with the "next"
5738 command. This problem has been fixed.
5740 *** Changes in GDB 6.2:
5742 * Fix for ``many threads''
5744 On GNU/Linux systems that use the NPTL threads library, a program
5745 rapidly creating and deleting threads would confuse GDB leading to the
5748 ptrace: No such process.
5749 thread_db_get_info: cannot get thread info: generic error
5751 This problem has been fixed.
5753 * "-async" and "-noasync" options removed.
5755 Support for the broken "-noasync" option has been removed (it caused
5758 * New ``start'' command.
5760 This command runs the program until the beginning of the main procedure.
5762 * New BSD Kernel Data Access Library (libkvm) interface
5764 Using ``target kvm'' it is now possible to debug kernel core dumps and
5765 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5766 platforms. Currently supported (native-only) configurations are:
5768 FreeBSD/amd64 x86_64-*-freebsd*
5769 FreeBSD/i386 i?86-*-freebsd*
5770 NetBSD/i386 i?86-*-netbsd*
5771 NetBSD/m68k m68*-*-netbsd*
5772 NetBSD/sparc sparc-*-netbsd*
5773 OpenBSD/amd64 x86_64-*-openbsd*
5774 OpenBSD/i386 i?86-*-openbsd*
5775 OpenBSD/m68k m68*-openbsd*
5776 OpenBSD/sparc sparc-*-openbsd*
5778 * Signal trampoline code overhauled
5780 Many generic problems with GDB's signal handling code have been fixed.
5781 These include: backtraces through non-contiguous stacks; recognition
5782 of sa_sigaction signal trampolines; backtrace from a NULL pointer
5783 call; backtrace through a signal trampoline; step into and out of
5784 signal handlers; and single-stepping in the signal trampoline.
5786 Please note that kernel bugs are a limiting factor here. These
5787 features have been shown to work on an s390 GNU/Linux system that
5788 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
5790 * Cygwin support for DWARF 2 added.
5792 * New native configurations
5794 GNU/Linux/hppa hppa*-*-linux*
5795 OpenBSD/hppa hppa*-*-openbsd*
5796 OpenBSD/m68k m68*-*-openbsd*
5797 OpenBSD/m88k m88*-*-openbsd*
5798 OpenBSD/powerpc powerpc-*-openbsd*
5799 NetBSD/vax vax-*-netbsd*
5800 OpenBSD/vax vax-*-openbsd*
5802 * END-OF-LIFE frame compatibility module
5804 GDB's internal frame infrastructure has been completely rewritten.
5805 The new infrastructure making it possible to support key new features
5806 including DWARF 2 Call Frame Information. To aid in the task of
5807 migrating old configurations to this new infrastructure, a
5808 compatibility module, that allowed old configurations to continue to
5809 work, was also included.
5811 GDB 6.2 will be the last release to include this frame compatibility
5812 module. This change directly impacts the following configurations:
5822 Unless there is activity to revive these configurations, they will be
5823 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
5825 * REMOVED configurations and files
5827 Sun 3, running SunOS 3 m68*-*-sunos3*
5828 Sun 3, running SunOS 4 m68*-*-sunos4*
5829 Sun 2, running SunOS 3 m68000-*-sunos3*
5830 Sun 2, running SunOS 4 m68000-*-sunos4*
5831 Motorola 680x0 running LynxOS m68*-*-lynxos*
5832 AT&T 3b1/Unix pc m68*-att-*
5833 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5834 decstation mips-dec-* mips-little-*
5835 riscos mips-*-riscos* mips-*-sysv*
5836 sonymips mips-sony-*
5837 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5839 *** Changes in GDB 6.1.1:
5841 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
5843 The TUI (Text-mode User Interface) is now built as part of a default
5844 GDB configuration. It is enabled by either selecting the TUI with the
5845 command line option "-i=tui" or by running the separate "gdbtui"
5846 program. For more information on the TUI, see the manual "Debugging
5849 * Pending breakpoint support (also included in GDB 6.1)
5851 Support has been added to allow you to specify breakpoints in shared
5852 libraries that have not yet been loaded. If a breakpoint location
5853 cannot be found, and the "breakpoint pending" option is set to auto,
5854 GDB queries you if you wish to make the breakpoint pending on a future
5855 shared-library load. If and when GDB resolves the breakpoint symbol,
5856 the pending breakpoint is removed as one or more regular breakpoints
5859 Pending breakpoints are very useful for GCJ Java debugging.
5861 * Fixed ISO-C build problems
5863 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
5864 non ISO-C code that stopped them being built using a more strict ISO-C
5865 compiler (e.g., IBM's C compiler).
5867 * Fixed build problem on IRIX 5
5869 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
5870 wasn't able to compile compile on an IRIX 5 system.
5872 * Added execute permission to gdb/gdbserver/configure
5874 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
5875 permission. This bug would cause configure to fail on a number of
5876 systems (Solaris, IRIX). Ref: server/519.
5878 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
5880 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
5881 has been updated to use constant array sizes.
5883 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
5885 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
5886 its generated DWARF Call Frame Info. This encoding was causing GDB to
5887 panic, that panic has been fixed. Ref: gdb/1628.
5889 * Fixed a problem when examining parameters in shared library code.
5891 When examining parameters in optimized shared library code generated
5892 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
5893 not available''. GDB now correctly displays the variable's value.
5895 *** Changes in GDB 6.1:
5897 * Removed --with-mmalloc
5899 Support for the mmalloc memory manager has been removed, as it
5900 conflicted with the internal gdb byte cache.
5902 * Changes in AMD64 configurations
5904 The AMD64 target now includes the %cs and %ss registers. As a result
5905 the AMD64 remote protocol has changed; this affects the floating-point
5906 and SSE registers. If you rely on those registers for your debugging,
5907 you should upgrade gdbserver on the remote side.
5909 * Revised SPARC target
5911 The SPARC target has been completely revised, incorporating the
5912 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
5913 support for LynxOS and SunOS 4 has been dropped. Calling functions
5914 from within GDB on operating systems with a non-executable stack
5915 (Solaris, OpenBSD) now works.
5919 GDB has a new C++ demangler which does a better job on the mangled
5920 names generated by current versions of g++. It also runs faster, so
5921 with this and other changes gdb should now start faster on large C++
5924 * DWARF 2 Location Expressions
5926 GDB support for location expressions has been extended to support function
5927 arguments and frame bases. Older versions of GDB could crash when they
5930 * C++ nested types and namespaces
5932 GDB's support for nested types and namespaces in C++ has been
5933 improved, especially if you use the DWARF 2 debugging format. (This
5934 is the default for recent versions of GCC on most platforms.)
5935 Specifically, if you have a class "Inner" defined within a class or
5936 namespace "Outer", then GDB realizes that the class's name is
5937 "Outer::Inner", not simply "Inner". This should greatly reduce the
5938 frequency of complaints about not finding RTTI symbols. In addition,
5939 if you are stopped at inside of a function defined within a namespace,
5940 GDB modifies its name lookup accordingly.
5942 * New native configurations
5944 NetBSD/amd64 x86_64-*-netbsd*
5945 OpenBSD/amd64 x86_64-*-openbsd*
5946 OpenBSD/alpha alpha*-*-openbsd*
5947 OpenBSD/sparc sparc-*-openbsd*
5948 OpenBSD/sparc64 sparc64-*-openbsd*
5950 * New debugging protocols
5952 M32R with SDI protocol m32r-*-elf*
5954 * "set prompt-escape-char" command deleted.
5956 The command "set prompt-escape-char" has been deleted. This command,
5957 and its very obscure effect on GDB's prompt, was never documented,
5958 tested, nor mentioned in the NEWS file.
5960 * OBSOLETE configurations and files
5962 Configurations that have been declared obsolete in this release have
5963 been commented out. Unless there is activity to revive these
5964 configurations, the next release of GDB will have their sources
5965 permanently REMOVED.
5967 Sun 3, running SunOS 3 m68*-*-sunos3*
5968 Sun 3, running SunOS 4 m68*-*-sunos4*
5969 Sun 2, running SunOS 3 m68000-*-sunos3*
5970 Sun 2, running SunOS 4 m68000-*-sunos4*
5971 Motorola 680x0 running LynxOS m68*-*-lynxos*
5972 AT&T 3b1/Unix pc m68*-att-*
5973 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
5974 decstation mips-dec-* mips-little-*
5975 riscos mips-*-riscos* mips-*-sysv*
5976 sonymips mips-sony-*
5977 sysv mips*-*-sysv4* (IRIX 5/6 not included)
5979 * REMOVED configurations and files
5981 SGI Irix-4.x mips-sgi-irix4 or iris4
5982 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5983 Z8000 simulator z8k-zilog-none or z8ksim
5984 Matsushita MN10200 w/simulator mn10200-*-*
5985 H8/500 simulator h8500-hitachi-hms or h8500hms
5986 HP/PA running BSD hppa*-*-bsd*
5987 HP/PA running OSF/1 hppa*-*-osf*
5988 HP/PA Pro target hppa*-*-pro*
5989 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5990 386BSD i[3456]86-*-bsd*
5991 Sequent family i[3456]86-sequent-sysv4*
5992 i[3456]86-sequent-sysv*
5993 i[3456]86-sequent-bsd*
5994 SPARC running LynxOS sparc-*-lynxos*
5995 SPARC running SunOS 4 sparc-*-sunos4*
5996 Tsqware Sparclet sparclet-*-*
5997 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5999 *** Changes in GDB 6.0:
6003 Support for debugging the Objective-C programming language has been
6004 integrated into GDB.
6006 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6008 DWARF 2's Call Frame Information makes available compiler generated
6009 information that more exactly describes the program's run-time stack.
6010 By using this information, GDB is able to provide more robust stack
6013 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6014 have been updated to use a new backtrace mechanism which includes
6015 DWARF 2 CFI support.
6019 GDB's remote protocol has been extended to include support for hosted
6020 file I/O (where the remote target uses GDB's file system). See GDB's
6021 remote protocol documentation for details.
6023 * All targets using the new architecture framework.
6025 All of GDB's targets have been updated to use the new internal
6026 architecture framework. The way is now open for future GDB releases
6027 to include cross-architecture native debugging support (i386 on amd64,
6030 * GNU/Linux's Thread Local Storage (TLS)
6032 GDB now includes support for for the GNU/Linux implementation of
6033 per-thread variables.
6035 * GNU/Linux's Native POSIX Thread Library (NPTL)
6037 GDB's thread code has been updated to work with either the new
6038 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6040 * Separate debug info.
6042 GDB, in conjunction with BINUTILS, now supports a mechanism for
6043 automatically loading debug information from a separate file. Instead
6044 of shipping full debug and non-debug versions of system libraries,
6045 system integrators can now instead ship just the stripped libraries
6046 and optional debug files.
6048 * DWARF 2 Location Expressions
6050 DWARF 2 Location Expressions allow the compiler to more completely
6051 describe the location of variables (even in optimized code) to the
6054 GDB now includes preliminary support for location expressions (support
6055 for DW_OP_piece is still missing).
6059 A number of long standing bugs that caused GDB to die while starting a
6060 Java application have been fixed. GDB's Java support is now
6061 considered "useable".
6063 * GNU/Linux support for fork, vfork, and exec.
6065 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6066 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6069 * GDB supports logging output to a file
6071 There are two new commands, "set logging" and "show logging", which can be
6072 used to capture GDB's output to a file.
6074 * The meaning of "detach" has changed for gdbserver
6076 The "detach" command will now resume the application, as documented. To
6077 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6080 * d10v, m68hc11 `regs' command deprecated
6082 The `info registers' command has been updated so that it displays the
6083 registers using a format identical to the old `regs' command.
6087 A new command, "maint set profile on/off", has been added. This command can
6088 be used to enable or disable profiling while running GDB, to profile a
6089 session or a set of commands. In addition there is a new configure switch,
6090 "--enable-profiling", which will cause GDB to be compiled with profiling
6091 data, for more informative profiling results.
6093 * Default MI syntax changed to "mi2".
6095 The default MI (machine interface) syntax, enabled by the command line
6096 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6097 "mi1", can be enabled by specifying the option "-i=mi1".
6099 Support for the original "mi0" syntax (included in GDB 5.0) has been
6102 Fix for gdb/192: removed extraneous space when displaying frame level.
6103 Fix for gdb/672: update changelist is now output in mi list format.
6104 Fix for gdb/702: a -var-assign that updates the value now shows up
6105 in a subsequent -var-update.
6107 * New native configurations.
6109 FreeBSD/amd64 x86_64-*-freebsd*
6111 * Multi-arched targets.
6113 HP/PA HPUX11 hppa*-*-hpux*
6114 Renesas M32R/D w/simulator m32r-*-elf*
6116 * OBSOLETE configurations and files
6118 Configurations that have been declared obsolete in this release have
6119 been commented out. Unless there is activity to revive these
6120 configurations, the next release of GDB will have their sources
6121 permanently REMOVED.
6123 Z8000 simulator z8k-zilog-none or z8ksim
6124 Matsushita MN10200 w/simulator mn10200-*-*
6125 H8/500 simulator h8500-hitachi-hms or h8500hms
6126 HP/PA running BSD hppa*-*-bsd*
6127 HP/PA running OSF/1 hppa*-*-osf*
6128 HP/PA Pro target hppa*-*-pro*
6129 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6130 Sequent family i[3456]86-sequent-sysv4*
6131 i[3456]86-sequent-sysv*
6132 i[3456]86-sequent-bsd*
6133 Tsqware Sparclet sparclet-*-*
6134 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6136 * REMOVED configurations and files
6139 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6140 IBM AIX PS/2 i[3456]86-*-aix
6141 i386 running Mach 3.0 i[3456]86-*-mach3*
6142 i386 running Mach i[3456]86-*-mach*
6143 i386 running OSF/1 i[3456]86-*osf1mk*
6144 HP/Apollo 68k Family m68*-apollo*-sysv*,
6146 m68*-hp-bsd*, m68*-hp-hpux*
6147 Argonaut Risc Chip (ARC) arc-*-*
6148 Mitsubishi D30V d30v-*-*
6149 Fujitsu FR30 fr30-*-elf*
6150 OS/9000 i[34]86-*-os9k
6151 I960 with MON960 i960-*-coff
6153 * MIPS $fp behavior changed
6155 The convenience variable $fp, for the MIPS, now consistently returns
6156 the address of the current frame's base. Previously, depending on the
6157 context, $fp could refer to either $sp or the current frame's base
6158 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6159 The GNU Source-Level Debugger''.
6161 *** Changes in GDB 5.3:
6163 * GNU/Linux shared library multi-threaded performance improved.
6165 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6166 `/proc', in preference to `ptrace' for memory reads. This may result
6167 in an improvement in the start-up time of multi-threaded, shared
6168 library applications when run under GDB. One GDB user writes: ``loads
6169 shared libs like mad''.
6171 * ``gdbserver'' now supports multi-threaded applications on some targets
6173 Support for debugging multi-threaded applications which use
6174 the GNU/Linux LinuxThreads package has been added for
6175 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6176 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6178 * GDB now supports C/C++ preprocessor macros.
6180 GDB now expands preprocessor macro invocations in C/C++ expressions,
6181 and provides various commands for showing macro definitions and how
6184 The new command `macro expand EXPRESSION' expands any macro
6185 invocations in expression, and shows the result.
6187 The new command `show macro MACRO-NAME' shows the definition of the
6188 macro named MACRO-NAME, and where it was defined.
6190 Most compilers don't include information about macros in the debugging
6191 information by default. In GCC 3.1, for example, you need to compile
6192 your program with the options `-gdwarf-2 -g3'. If the macro
6193 information is present in the executable, GDB will read it.
6195 * Multi-arched targets.
6197 DEC Alpha (partial) alpha*-*-*
6198 DEC VAX (partial) vax-*-*
6200 National Semiconductor NS32000 (partial) ns32k-*-*
6201 Motorola 68000 (partial) m68k-*-*
6202 Motorola MCORE mcore-*-*
6206 Fujitsu FRV architecture added by Red Hat frv*-*-*
6209 * New native configurations
6211 Alpha NetBSD alpha*-*-netbsd*
6212 SH NetBSD sh*-*-netbsdelf*
6213 MIPS NetBSD mips*-*-netbsd*
6214 UltraSPARC NetBSD sparc64-*-netbsd*
6216 * OBSOLETE configurations and files
6218 Configurations that have been declared obsolete in this release have
6219 been commented out. Unless there is activity to revive these
6220 configurations, the next release of GDB will have their sources
6221 permanently REMOVED.
6223 Mitsubishi D30V d30v-*-*
6224 OS/9000 i[34]86-*-os9k
6225 IBM AIX PS/2 i[3456]86-*-aix
6226 Fujitsu FR30 fr30-*-elf*
6227 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6228 Argonaut Risc Chip (ARC) arc-*-*
6229 i386 running Mach 3.0 i[3456]86-*-mach3*
6230 i386 running Mach i[3456]86-*-mach*
6231 i386 running OSF/1 i[3456]86-*osf1mk*
6232 HP/Apollo 68k Family m68*-apollo*-sysv*,
6234 m68*-hp-bsd*, m68*-hp-hpux*
6235 I960 with MON960 i960-*-coff
6237 * OBSOLETE languages
6239 CHILL, a Pascal like language used by telecommunications companies.
6241 * REMOVED configurations and files
6243 AMD 29k family via UDI a29k-amd-udi, udi29k
6244 A29K VxWorks a29k-*-vxworks
6245 AMD 29000 embedded, using EBMON a29k-none-none
6246 AMD 29000 embedded with COFF a29k-none-coff
6247 AMD 29000 embedded with a.out a29k-none-aout
6249 testsuite/gdb.hp/gdb.threads-hp/ directory
6251 * New command "set max-user-call-depth <nnn>"
6253 This command allows the user to limit the call depth of user-defined
6254 commands. The default is 1024.
6256 * Changes in FreeBSD/i386 native debugging.
6258 Support for the "generate-core-file" has been added.
6260 * New commands "dump", "append", and "restore".
6262 These commands allow data to be copied from target memory
6263 to a bfd-format or binary file (dump and append), and back
6264 from a file into memory (restore).
6266 * Improved "next/step" support on multi-processor Alpha Tru64.
6268 The previous single-step mechanism could cause unpredictable problems,
6269 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6270 of a software single-step mechanism prevents this.
6272 *** Changes in GDB 5.2.1:
6280 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6281 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6282 Fix, by Joel Brobecker imported from mainline.
6284 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6285 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6286 Fix, by Fred Fish, imported from mainline.
6288 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6289 Surprisingly enough, it works now.
6290 By Michal Ludvig, imported from mainline.
6292 i386 hardware watchpoint support:
6293 avoid misses on second run for some targets.
6294 By Pierre Muller, imported from mainline.
6296 *** Changes in GDB 5.2:
6298 * New command "set trust-readonly-sections on[off]".
6300 This command is a hint that tells gdb that read-only sections
6301 really are read-only (ie. that their contents will not change).
6302 In this mode, gdb will go to the object file rather than the
6303 target to read memory from read-only sections (such as ".text").
6304 This can be a significant performance improvement on some
6305 (notably embedded) targets.
6307 * New command "generate-core-file" (or "gcore").
6309 This new gdb command allows the user to drop a core file of the child
6310 process state at any time. So far it's been implemented only for
6311 GNU/Linux and Solaris, but should be relatively easily ported to other
6312 hosts. Argument is core file name (defaults to core.<pid>).
6314 * New command line option
6316 GDB now accepts --pid or -p followed by a process id.
6318 * Change in command line behavior -- corefiles vs. process ids.
6320 There is a subtle behavior in the way in which GDB handles
6321 command line arguments. The first non-flag argument is always
6322 a program to debug, but the second non-flag argument may either
6323 be a corefile or a process id. Previously, GDB would attempt to
6324 open the second argument as a corefile, and if that failed, would
6325 issue a superfluous error message and then attempt to attach it as
6326 a process. Now, if the second argument begins with a non-digit,
6327 it will be treated as a corefile. If it begins with a digit,
6328 GDB will attempt to attach it as a process, and if no such process
6329 is found, will then attempt to open it as a corefile.
6331 * Changes in ARM configurations.
6333 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6334 configuration is fully multi-arch.
6336 * New native configurations
6338 ARM NetBSD arm*-*-netbsd*
6339 x86 OpenBSD i[3456]86-*-openbsd*
6340 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6341 Sparc64 running FreeBSD sparc64-*-freebsd*
6345 Sanyo XStormy16 xstormy16-elf
6347 * OBSOLETE configurations and files
6349 Configurations that have been declared obsolete in this release have
6350 been commented out. Unless there is activity to revive these
6351 configurations, the next release of GDB will have their sources
6352 permanently REMOVED.
6354 AMD 29k family via UDI a29k-amd-udi, udi29k
6355 A29K VxWorks a29k-*-vxworks
6356 AMD 29000 embedded, using EBMON a29k-none-none
6357 AMD 29000 embedded with COFF a29k-none-coff
6358 AMD 29000 embedded with a.out a29k-none-aout
6360 testsuite/gdb.hp/gdb.threads-hp/ directory
6362 * REMOVED configurations and files
6364 TI TMS320C80 tic80-*-*
6366 PowerPC Solaris powerpcle-*-solaris*
6367 PowerPC Windows NT powerpcle-*-cygwin32
6368 PowerPC Netware powerpc-*-netware*
6369 Harris/CXUX m88k m88*-harris-cxux*
6370 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6371 ns32k-utek-sysv* ns32k-utek-*
6372 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6373 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6374 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6375 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6376 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6378 * Changes to command line processing
6380 The new `--args' feature can be used to specify command-line arguments
6381 for the inferior from gdb's command line.
6383 * Changes to key bindings
6385 There is a new `operate-and-get-next' function bound to `C-o'.
6387 *** Changes in GDB 5.1.1
6389 Fix compile problem on DJGPP.
6391 Fix a problem with floating-point registers on the i386 being
6394 Fix to stop GDB crashing on .debug_str debug info.
6396 Numerous documentation fixes.
6398 Numerous testsuite fixes.
6400 *** Changes in GDB 5.1:
6402 * New native configurations
6404 Alpha FreeBSD alpha*-*-freebsd*
6405 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6406 MIPS GNU/Linux mips*-*-linux*
6407 MIPS SGI Irix 6.x mips*-sgi-irix6*
6408 ia64 AIX ia64-*-aix*
6409 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6413 Motorola 68HC11 and 68HC12 m68hc11-elf
6415 UltraSparc running GNU/Linux sparc64-*-linux*
6417 * OBSOLETE configurations and files
6419 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6420 Harris/CXUX m88k m88*-harris-cxux*
6421 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6422 ns32k-utek-sysv* ns32k-utek-*
6423 TI TMS320C80 tic80-*-*
6425 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6426 PowerPC Solaris powerpcle-*-solaris*
6427 PowerPC Windows NT powerpcle-*-cygwin32
6428 PowerPC Netware powerpc-*-netware*
6429 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6430 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6431 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6432 Apple Macintosh (MPW) host N/A
6434 stuff.c (Program to stuff files into a specially prepared space in kdb)
6435 kdb-start.c (Main loop for the standalone kernel debugger)
6437 Configurations that have been declared obsolete in this release have
6438 been commented out. Unless there is activity to revive these
6439 configurations, the next release of GDB will have their sources
6440 permanently REMOVED.
6442 * REMOVED configurations and files
6444 Altos 3068 m68*-altos-*
6445 Convex c1-*-*, c2-*-*
6447 ARM RISCix arm-*-* (as host)
6451 * GDB has been converted to ISO C.
6453 GDB's source code has been converted to ISO C. In particular, the
6454 sources are fully protoized, and rely on standard headers being
6459 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6461 * The MI enabled by default.
6463 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6464 revised and enabled by default. Packages which use GDB as a debugging
6465 engine behind a UI or another front end are encouraged to switch to
6466 using the GDB/MI interface, instead of the old annotations interface
6467 which is now deprecated.
6469 * Support for debugging Pascal programs.
6471 GDB now includes support for debugging Pascal programs. The following
6472 main features are supported:
6474 - Pascal-specific data types such as sets;
6476 - automatic recognition of Pascal sources based on file-name
6479 - Pascal-style display of data types, variables, and functions;
6481 - a Pascal expression parser.
6483 However, some important features are not yet supported.
6485 - Pascal string operations are not supported at all;
6487 - there are some problems with boolean types;
6489 - Pascal type hexadecimal constants are not supported
6490 because they conflict with the internal variables format;
6492 - support for Pascal objects and classes is not full yet;
6494 - unlike Pascal, GDB is case-sensitive for symbol names.
6496 * Changes in completion.
6498 Commands such as `shell', `run' and `set args', which pass arguments
6499 to inferior programs, now complete on file names, similar to what
6500 users expect at the shell prompt.
6502 Commands which accept locations, such as `disassemble', `print',
6503 `breakpoint', `until', etc. now complete on filenames as well as
6504 program symbols. Thus, if you type "break foob TAB", and the source
6505 files linked into the programs include `foobar.c', that file name will
6506 be one of the candidates for completion. However, file names are not
6507 considered for completion after you typed a colon that delimits a file
6508 name from a name of a function in that file, as in "break foo.c:bar".
6510 `set demangle-style' completes on available demangling styles.
6512 * New platform-independent commands:
6514 It is now possible to define a post-hook for a command as well as a
6515 hook that runs before the command. For more details, see the
6516 documentation of `hookpost' in the GDB manual.
6518 * Changes in GNU/Linux native debugging.
6520 Support for debugging multi-threaded programs has been completely
6521 revised for all platforms except m68k and sparc. You can now debug as
6522 many threads as your system allows you to have.
6524 Attach/detach is supported for multi-threaded programs.
6526 Support for SSE registers was added for x86. This doesn't work for
6527 multi-threaded programs though.
6529 * Changes in MIPS configurations.
6531 Multi-arch support is enabled for all MIPS configurations.
6533 GDB can now be built as native debugger on SGI Irix 6.x systems for
6534 debugging n32 executables. (Debugging 64-bit executables is not yet
6537 * Unified support for hardware watchpoints in all x86 configurations.
6539 Most (if not all) native x86 configurations support hardware-assisted
6540 breakpoints and watchpoints in a unified manner. This support
6541 implements debug register sharing between watchpoints, which allows to
6542 put a virtually infinite number of watchpoints on the same address,
6543 and also supports watching regions up to 16 bytes with several debug
6546 The new maintenance command `maintenance show-debug-regs' toggles
6547 debugging print-outs in functions that insert, remove, and test
6548 watchpoints and hardware breakpoints.
6550 * Changes in the DJGPP native configuration.
6552 New command ``info dos sysinfo'' displays assorted information about
6553 the CPU, OS, memory, and DPMI server.
6555 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6556 display information about segment descriptors stored in GDT, LDT, and
6559 New commands ``info dos pde'' and ``info dos pte'' display entries
6560 from Page Directory and Page Tables (for now works with CWSDPMI only).
6561 New command ``info dos address-pte'' displays the Page Table entry for
6562 a given linear address.
6564 GDB can now pass command lines longer than 126 characters to the
6565 program being debugged (requires an update to the libdbg.a library
6566 which is part of the DJGPP development kit).
6568 DWARF2 debug info is now supported.
6570 It is now possible to `step' and `next' through calls to `longjmp'.
6572 * Changes in documentation.
6574 All GDB documentation was converted to GFDL, the GNU Free
6575 Documentation License.
6577 Tracepoints-related commands are now fully documented in the GDB
6580 TUI, the Text-mode User Interface, is now documented in the manual.
6582 Tracepoints-related commands are now fully documented in the GDB
6585 The "GDB Internals" manual now has an index. It also includes
6586 documentation of `ui_out' functions, GDB coding standards, x86
6587 hardware watchpoints, and memory region attributes.
6589 * GDB's version number moved to ``version.in''
6591 The Makefile variable VERSION has been replaced by the file
6592 ``version.in''. People creating GDB distributions should update the
6593 contents of this file.
6597 GUD support is now a standard part of the EMACS distribution.
6599 *** Changes in GDB 5.0:
6601 * Improved support for debugging FP programs on x86 targets
6603 Unified and much-improved support for debugging floating-point
6604 programs on all x86 targets. In particular, ``info float'' now
6605 displays the FP registers in the same format on all x86 targets, with
6606 greater level of detail.
6608 * Improvements and bugfixes in hardware-assisted watchpoints
6610 It is now possible to watch array elements, struct members, and
6611 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6612 on x86 targets no longer erroneously trigger when the address is
6615 * Improvements in the native DJGPP version of GDB
6617 The distribution now includes all the scripts and auxiliary files
6618 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6619 machines ``out of the box''.
6621 The DJGPP version can now debug programs that use signals. It is
6622 possible to catch signals that happened in the debuggee, deliver
6623 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6624 would kill the program being debugged.) Programs that hook hardware
6625 interrupts (keyboard, timer, etc.) can also be debugged.
6627 It is now possible to debug DJGPP programs that redirect their
6628 standard handles or switch them to raw (as opposed to cooked) mode, or
6629 even close them. The command ``run < foo > bar'' works as expected,
6630 and ``info terminal'' reports useful information about the debuggee's
6631 terminal, including raw/cooked mode, redirection, etc.
6633 The DJGPP version now uses termios functions for console I/O, which
6634 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6637 DOS-style file names with drive letters are now fully supported by
6640 It is now possible to debug DJGPP programs that switch their working
6641 directory. It is also possible to rerun the debuggee any number of
6642 times without restarting GDB; thus, you can use the same setup,
6643 breakpoints, etc. for many debugging sessions.
6645 * New native configurations
6647 ARM GNU/Linux arm*-*-linux*
6648 PowerPC GNU/Linux powerpc-*-linux*
6652 Motorola MCore mcore-*-*
6653 x86 VxWorks i[3456]86-*-vxworks*
6654 PowerPC VxWorks powerpc-*-vxworks*
6655 TI TMS320C80 tic80-*-*
6657 * OBSOLETE configurations
6659 Altos 3068 m68*-altos-*
6660 Convex c1-*-*, c2-*-*
6662 ARM RISCix arm-*-* (as host)
6665 Configurations that have been declared obsolete will be commented out,
6666 but the code will be left in place. If there is no activity to revive
6667 these configurations before the next release of GDB, the sources will
6668 be permanently REMOVED.
6670 * Gould support removed
6672 Support for the Gould PowerNode and NP1 has been removed.
6674 * New features for SVR4
6676 On SVR4 native platforms (such as Solaris), if you attach to a process
6677 without first loading a symbol file, GDB will now attempt to locate and
6678 load symbols from the running process's executable file.
6680 * Many C++ enhancements
6682 C++ support has been greatly improved. Overload resolution now works properly
6683 in almost all cases. RTTI support is on the way.
6685 * Remote targets can connect to a sub-program
6687 A popen(3) style serial-device has been added. This device starts a
6688 sub-process (such as a stand-alone simulator) and then communicates
6689 with that. The sub-program to run is specified using the syntax
6690 ``|<program> <args>'' vis:
6692 (gdb) set remotedebug 1
6693 (gdb) target extended-remote |mn10300-elf-sim program-args
6695 * MIPS 64 remote protocol
6697 A long standing bug in the mips64 remote protocol where by GDB
6698 expected certain 32 bit registers (ex SR) to be transfered as 32
6699 instead of 64 bits has been fixed.
6701 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6702 added to provide backward compatibility with older versions of GDB.
6704 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6706 The command ``set remotebinarydownload'' command has been replaced by
6707 ``set remote X-packet''. Other commands in ``set remote'' family
6708 include ``set remote P-packet''.
6710 * Breakpoint commands accept ranges.
6712 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6713 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6714 ``tracepoint passcount'' also accepts a range of tracepoints.
6716 * ``apropos'' command added.
6718 The ``apropos'' command searches through command names and
6719 documentation strings, printing out matches, making it much easier to
6720 try to find a command that does what you are looking for.
6724 A new machine oriented interface (MI) has been added to GDB. This
6725 interface is designed for debug environments running GDB as a separate
6726 process. This is part of the long term libGDB project. See the
6727 "GDB/MI" chapter of the GDB manual for further information. It can be
6728 enabled by configuring with:
6730 .../configure --enable-gdbmi
6732 *** Changes in GDB-4.18:
6734 * New native configurations
6736 HP-UX 10.20 hppa*-*-hpux10.20
6737 HP-UX 11.x hppa*-*-hpux11.0*
6738 M68K GNU/Linux m68*-*-linux*
6742 Fujitsu FR30 fr30-*-elf*
6743 Intel StrongARM strongarm-*-*
6744 Mitsubishi D30V d30v-*-*
6746 * OBSOLETE configurations
6748 Gould PowerNode, NP1 np1-*-*, pn-*-*
6750 Configurations that have been declared obsolete will be commented out,
6751 but the code will be left in place. If there is no activity to revive
6752 these configurations before the next release of GDB, the sources will
6753 be permanently REMOVED.
6757 As a compatibility experiment, GDB's source files buildsym.h and
6758 buildsym.c have been converted to pure standard C, no longer
6759 containing any K&R compatibility code. We believe that all systems in
6760 use today either come with a standard C compiler, or have a GCC port
6761 available. If this is not true, please report the affected
6762 configuration to bug-gdb@gnu.org immediately. See the README file for
6763 information about getting a standard C compiler if you don't have one
6768 GDB now uses readline 2.2.
6770 * set extension-language
6772 You can now control the mapping between filename extensions and source
6773 languages by using the `set extension-language' command. For instance,
6774 you can ask GDB to treat .c files as C++ by saying
6775 set extension-language .c c++
6776 The command `info extensions' lists all of the recognized extensions
6777 and their associated languages.
6779 * Setting processor type for PowerPC and RS/6000
6781 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
6782 you can use the `set processor' command to specify what variant of the
6783 PowerPC family you are debugging. The command
6787 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
6788 following PowerPC and RS6000 variants:
6790 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
6791 rs6000 IBM RS6000 ("POWER") architecture, user-level view
6793 403GC IBM PowerPC 403GC
6794 505 Motorola PowerPC 505
6795 860 Motorola PowerPC 860 or 850
6796 601 Motorola PowerPC 601
6797 602 Motorola PowerPC 602
6798 603 Motorola/IBM PowerPC 603 or 603e
6799 604 Motorola PowerPC 604 or 604e
6800 750 Motorola/IBM PowerPC 750 or 750
6802 At the moment, this command just tells GDB what to name the
6803 special-purpose processor registers. Since almost all the affected
6804 registers are inaccessible to user-level programs, this command is
6805 only useful for remote debugging in its present form.
6809 Thanks to a major code donation from Hewlett-Packard, GDB now has much
6810 more extensive support for HP-UX. Added features include shared
6811 library support, kernel threads and hardware watchpoints for 11.00,
6812 support for HP's ANSI C and C++ compilers, and a compatibility mode
6813 for xdb and dbx commands.
6817 HP's donation includes the new concept of catchpoints, which is a
6818 generalization of the old catch command. On HP-UX, it is now possible
6819 to catch exec, fork, and vfork, as well as library loading.
6821 This means that the existing catch command has changed; its first
6822 argument now specifies the type of catch to be set up. See the
6823 output of "help catch" for a list of catchpoint types.
6825 * Debugging across forks
6827 On HP-UX, you can choose which process to debug when a fork() happens
6832 HP has donated a curses-based terminal user interface (TUI). To get
6833 it, build with --enable-tui. Although this can be enabled for any
6834 configuration, at present it only works for native HP debugging.
6836 * GDB remote protocol additions
6838 A new protocol packet 'X' that writes binary data is now available.
6839 Default behavior is to try 'X', then drop back to 'M' if the stub
6840 fails to respond. The settable variable `remotebinarydownload'
6841 allows explicit control over the use of 'X'.
6843 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
6844 full 64-bit address. The command
6846 set remoteaddresssize 32
6848 can be used to revert to the old behaviour. For existing remote stubs
6849 the change should not be noticed, as the additional address information
6852 In order to assist in debugging stubs, you may use the maintenance
6853 command `packet' to send any text string to the stub. For instance,
6855 maint packet heythere
6857 sends the packet "$heythere#<checksum>". Note that it is very easy to
6858 disrupt a debugging session by sending the wrong packet at the wrong
6861 The compare-sections command allows you to compare section data on the
6862 target to what is in the executable file without uploading or
6863 downloading, by comparing CRC checksums.
6865 * Tracing can collect general expressions
6867 You may now collect general expressions at tracepoints. This requires
6868 further additions to the target-side stub; see tracepoint.c and
6869 doc/agentexpr.texi for further details.
6871 * mask-address variable for Mips
6873 For Mips targets, you may control the zeroing of the upper 32 bits of
6874 a 64-bit address by entering `set mask-address on'. This is mainly
6875 of interest to users of embedded R4xxx and R5xxx processors.
6877 * Higher serial baud rates
6879 GDB's serial code now allows you to specify baud rates 57600, 115200,
6880 230400, and 460800 baud. (Note that your host system may not be able
6881 to achieve all of these rates.)
6885 The i960 configuration now includes an initial implementation of a
6886 builtin simulator, contributed by Jim Wilson.
6889 *** Changes in GDB-4.17:
6891 * New native configurations
6893 Alpha GNU/Linux alpha*-*-linux*
6894 Unixware 2.x i[3456]86-unixware2*
6895 Irix 6.x mips*-sgi-irix6*
6896 PowerPC GNU/Linux powerpc-*-linux*
6897 PowerPC Solaris powerpcle-*-solaris*
6898 Sparc GNU/Linux sparc-*-linux*
6899 Motorola sysV68 R3V7.1 m68k-motorola-sysv
6903 Argonaut Risc Chip (ARC) arc-*-*
6904 Hitachi H8/300S h8300*-*-*
6905 Matsushita MN10200 w/simulator mn10200-*-*
6906 Matsushita MN10300 w/simulator mn10300-*-*
6907 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
6908 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
6909 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
6910 Mitsubishi D10V w/simulator d10v-*-*
6911 Mitsubishi M32R/D w/simulator m32r-*-elf*
6912 Tsqware Sparclet sparclet-*-*
6913 NEC V850 w/simulator v850-*-*
6915 * New debugging protocols
6917 ARM with RDI protocol arm*-*-*
6918 M68K with dBUG monitor m68*-*-{aout,coff,elf}
6919 DDB and LSI variants of PMON protocol mips*-*-*
6920 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
6921 PowerPC with SDS protocol powerpc{,le}-*-eabi
6922 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
6926 All configurations can now understand and use the DWARF 2 debugging
6927 format. The choice is automatic, if the symbol file contains DWARF 2
6932 GDB now includes basic Java language support. This support is
6933 only useful with Java compilers that produce native machine code.
6935 * solib-absolute-prefix and solib-search-path
6937 For SunOS and SVR4 shared libraries, you may now set the prefix for
6938 loading absolute shared library symbol files, and the search path for
6939 locating non-absolute shared library symbol files.
6941 * Live range splitting
6943 GDB can now effectively debug code for which GCC has performed live
6944 range splitting as part of its optimization. See gdb/doc/LRS for
6945 more details on the expected format of the stabs information.
6949 GDB's support for the GNU Hurd, including thread debugging, has been
6950 updated to work with current versions of the Hurd.
6954 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
6955 instruction set. ARM GDB automatically detects when Thumb
6956 instructions are in use, and adjusts disassembly and backtracing
6961 GDB's MIPS target configurations now handle the MIP16 16-bit
6966 GDB now includes support for overlays; if an executable has been
6967 linked such that multiple sections are based at the same address, GDB
6968 will decide which section to use for symbolic info. You can choose to
6969 control the decision manually, using overlay commands, or implement
6970 additional target-side support and use "overlay load-target" to bring
6971 in the overlay mapping. Do "help overlay" for more detail.
6975 The command "info symbol <address>" displays information about
6976 the symbol at the specified address.
6980 The standard remote protocol now includes an extension that allows
6981 asynchronous collection and display of trace data. This requires
6982 extensive support in the target-side debugging stub. Tracing mode
6983 includes a new interaction mode in GDB and new commands: see the
6984 file tracepoint.c for more details.
6988 Configurations for embedded MIPS now include a simulator contributed
6989 by Cygnus Solutions. The simulator supports the instruction sets
6990 of most MIPS variants.
6994 Sparc configurations may now include the ERC32 simulator contributed
6995 by the European Space Agency. The simulator is not built into
6996 Sparc targets by default; configure with --enable-sim to include it.
7000 For target configurations that may include multiple variants of a
7001 basic architecture (such as MIPS and SH), you may now set the
7002 architecture explicitly. "set arch" sets, "info arch" lists
7003 the possible architectures.
7005 *** Changes in GDB-4.16:
7007 * New native configurations
7009 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7010 M68K NetBSD m68k-*-netbsd*
7011 PowerPC AIX 4.x powerpc-*-aix*
7012 PowerPC MacOS powerpc-*-macos*
7013 PowerPC Windows NT powerpcle-*-cygwin32
7014 RS/6000 AIX 4.x rs6000-*-aix4*
7018 ARM with RDP protocol arm-*-*
7019 I960 with MON960 i960-*-coff
7020 MIPS VxWorks mips*-*-vxworks*
7021 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7022 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7024 Matra Sparclet sparclet-*-*
7028 The powerpc-eabi configuration now includes the PSIM simulator,
7029 contributed by Andrew Cagney, with assistance from Mike Meissner.
7030 PSIM is a very elaborate model of the PowerPC, including not only
7031 basic instruction set execution, but also details of execution unit
7032 performance and I/O hardware. See sim/ppc/README for more details.
7036 GDB now works with Solaris 2.5.
7038 * Windows 95/NT native
7040 GDB will now work as a native debugger on Windows 95 and Windows NT.
7041 To build it from source, you must use the "gnu-win32" environment,
7042 which uses a DLL to emulate enough of Unix to run the GNU tools.
7043 Further information, binaries, and sources are available at
7044 ftp.cygnus.com, under pub/gnu-win32.
7046 * dont-repeat command
7048 If a user-defined command includes the command `dont-repeat', then the
7049 command will not be repeated if the user just types return. This is
7050 useful if the command is time-consuming to run, so that accidental
7051 extra keystrokes don't run the same command many times.
7053 * Send break instead of ^C
7055 The standard remote protocol now includes an option to send a break
7056 rather than a ^C to the target in order to interrupt it. By default,
7057 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7059 * Remote protocol timeout
7061 The standard remote protocol includes a new variable `remotetimeout'
7062 that allows you to set the number of seconds before GDB gives up trying
7063 to read from the target. The default value is 2.
7065 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7067 By default GDB will automatically keep track of objects as they are
7068 loaded and unloaded by the dynamic linker. By using the command `set
7069 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7070 when shared library events occur, thus allowing you to set breakpoints
7071 in shared libraries which are explicitly loaded by the inferior.
7073 Note this feature does not work on hpux8. On hpux9 you must link
7074 /usr/lib/end.o into your program. This feature should work
7075 automatically on hpux10.
7077 * Irix 5.x hardware watchpoint support
7079 Irix 5 configurations now support the use of hardware watchpoints.
7081 * Mips protocol "SYN garbage limit"
7083 When debugging a Mips target using the `target mips' protocol, you
7084 may set the number of characters that GDB will ignore by setting
7085 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7086 every character. The default value is 1050.
7088 * Recording and replaying remote debug sessions
7090 If you set `remotelogfile' to the name of a file, gdb will write to it
7091 a recording of a remote debug session. This recording may then be
7092 replayed back to gdb using "gdbreplay". See gdbserver/README for
7093 details. This is useful when you have a problem with GDB while doing
7094 remote debugging; you can make a recording of the session and send it
7095 to someone else, who can then recreate the problem.
7097 * Speedups for remote debugging
7099 GDB includes speedups for downloading and stepping MIPS systems using
7100 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7101 and more efficient S-record downloading.
7103 * Memory use reductions and statistics collection
7105 GDB now uses less memory and reports statistics about memory usage.
7106 Try the `maint print statistics' command, for example.
7108 *** Changes in GDB-4.15:
7110 * Psymtabs for XCOFF
7112 The symbol reader for AIX GDB now uses partial symbol tables. This
7113 can greatly improve startup time, especially for large executables.
7115 * Remote targets use caching
7117 Remote targets now use a data cache to speed up communication with the
7118 remote side. The data cache could lead to incorrect results because
7119 it doesn't know about volatile variables, thus making it impossible to
7120 debug targets which use memory mapped I/O devices. `set remotecache
7121 off' turns the data cache off.
7123 * Remote targets may have threads
7125 The standard remote protocol now includes support for multiple threads
7126 in the target system, using new protocol commands 'H' and 'T'. See
7127 gdb/remote.c for details.
7131 If GDB is configured with `--enable-netrom', then it will include
7132 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7133 acts as though it is a bank of ROM on the target board, but you can
7134 write into it over the network. GDB's support consists only of
7135 support for fast loading into the emulated ROM; to debug, you must use
7136 another protocol, such as standard remote protocol. The usual
7137 sequence is something like
7139 target nrom <netrom-hostname>
7141 target remote <netrom-hostname>:1235
7145 GDB now includes support for the Apple Macintosh, as a host only. It
7146 may be run as either an MPW tool or as a standalone application, and
7147 it can debug through the serial port. All the usual GDB commands are
7148 available, but to the target command, you must supply "serial" as the
7149 device type instead of "/dev/ttyXX". See mpw-README in the main
7150 directory for more information on how to build. The MPW configuration
7151 scripts */mpw-config.in support only a few targets, and only the
7152 mips-idt-ecoff target has been tested.
7156 GDB configuration now uses autoconf. This is not user-visible,
7157 but does simplify configuration and building.
7161 GDB now supports hpux10.
7163 *** Changes in GDB-4.14:
7165 * New native configurations
7167 x86 FreeBSD i[345]86-*-freebsd
7168 x86 NetBSD i[345]86-*-netbsd
7169 NS32k NetBSD ns32k-*-netbsd
7170 Sparc NetBSD sparc-*-netbsd
7174 A29K VxWorks a29k-*-vxworks
7175 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7176 CPU32 EST-300 emulator m68*-*-est*
7177 PowerPC ELF powerpc-*-elf
7180 * Alpha OSF/1 support for procfs
7182 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7183 possible to attach to running processes. As the mounting of the /proc
7184 filesystem is optional on the Alpha, GDB automatically determines
7185 the availability of /proc during startup. This can lead to problems
7186 if /proc is unmounted after GDB has been started.
7188 * Arguments to user-defined commands
7190 User commands may accept up to 10 arguments separated by whitespace.
7191 Arguments are accessed within the user command via $arg0..$arg9. A
7194 print $arg0 + $arg1 + $arg2
7196 To execute the command use:
7199 Defines the command "adder" which prints the sum of its three arguments.
7200 Note the arguments are text substitutions, so they may reference variables,
7201 use complex expressions, or even perform inferior function calls.
7203 * New `if' and `while' commands
7205 This makes it possible to write more sophisticated user-defined
7206 commands. Both commands take a single argument, which is the
7207 expression to evaluate, and must be followed by the commands to
7208 execute, one per line, if the expression is nonzero, the list being
7209 terminated by the word `end'. The `if' command list may include an
7210 `else' word, which causes the following commands to be executed only
7211 if the expression is zero.
7213 * Fortran source language mode
7215 GDB now includes partial support for Fortran 77. It will recognize
7216 Fortran programs and can evaluate a subset of Fortran expressions, but
7217 variables and functions may not be handled correctly. GDB will work
7218 with G77, but does not yet know much about symbols emitted by other
7221 * Better HPUX support
7223 Most debugging facilities now work on dynamic executables for HPPAs
7224 running hpux9 or later. You can attach to running dynamically linked
7225 processes, but by default the dynamic libraries will be read-only, so
7226 for instance you won't be able to put breakpoints in them. To change
7227 that behavior do the following before running the program:
7233 This will cause the libraries to be mapped private and read-write.
7234 To revert to the normal behavior, do this:
7240 You cannot set breakpoints or examine data in the library until after
7241 the library is loaded if the function/data symbols do not have
7244 GDB can now also read debug symbols produced by the HP C compiler on
7245 HPPAs (sorry, no C++, Fortran or 68k support).
7247 * Target byte order now dynamically selectable
7249 You can choose which byte order to use with a target system, via the
7250 commands "set endian big" and "set endian little", and you can see the
7251 current setting by using "show endian". You can also give the command
7252 "set endian auto", in which case GDB will use the byte order
7253 associated with the executable. Currently, only embedded MIPS
7254 configurations support dynamic selection of target byte order.
7256 * New DOS host serial code
7258 This version uses DPMI interrupts to handle buffered I/O, so you
7259 no longer need to run asynctsr when debugging boards connected to
7262 *** Changes in GDB-4.13:
7264 * New "complete" command
7266 This lists all the possible completions for the rest of the line, if it
7267 were to be given as a command itself. This is intended for use by emacs.
7269 * Trailing space optional in prompt
7271 "set prompt" no longer adds a space for you after the prompt you set. This
7272 allows you to set a prompt which ends in a space or one that does not.
7274 * Breakpoint hit counts
7276 "info break" now displays a count of the number of times the breakpoint
7277 has been hit. This is especially useful in conjunction with "ignore"; you
7278 can ignore a large number of breakpoint hits, look at the breakpoint info
7279 to see how many times the breakpoint was hit, then run again, ignoring one
7280 less than that number, and this will get you quickly to the last hit of
7283 * Ability to stop printing at NULL character
7285 "set print null-stop" will cause GDB to stop printing the characters of
7286 an array when the first NULL is encountered. This is useful when large
7287 arrays actually contain only short strings.
7289 * Shared library breakpoints
7291 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7292 breakpoints in shared libraries before the executable is run.
7294 * Hardware watchpoints
7296 There is a new hardware breakpoint for the watch command for sparclite
7297 targets. See gdb/sparclite/hw_breakpoint.note.
7299 Hardware watchpoints are also now supported under GNU/Linux.
7303 Annotations have been added. These are for use with graphical interfaces,
7304 and are still experimental. Currently only gdba.el uses these.
7306 * Improved Irix 5 support
7308 GDB now works properly with Irix 5.2.
7310 * Improved HPPA support
7312 GDB now works properly with the latest GCC and GAS.
7314 * New native configurations
7316 Sequent PTX4 i[34]86-sequent-ptx4
7317 HPPA running OSF/1 hppa*-*-osf*
7318 Atari TT running SVR4 m68*-*-sysv4*
7319 RS/6000 LynxOS rs6000-*-lynxos*
7323 OS/9000 i[34]86-*-os9k
7324 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7327 * Hitachi SH7000 and E7000-PC ICE support
7329 There is now support for communicating with the Hitachi E7000-PC ICE.
7330 This is available automatically when GDB is configured for the SH.
7334 As usual, a variety of small fixes and improvements, both generic
7335 and configuration-specific. See the ChangeLog for more detail.
7337 *** Changes in GDB-4.12:
7339 * Irix 5 is now supported
7343 GDB-4.12 on the HPPA has a number of changes which make it unable
7344 to debug the output from the currently released versions of GCC and
7345 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7346 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7347 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7350 *** Changes in GDB-4.11:
7352 * User visible changes:
7356 The "set remotedebug" option is now consistent between the mips remote
7357 target, remote targets using the gdb-specific protocol, UDI (AMD's
7358 debug protocol for the 29k) and the 88k bug monitor. It is now an
7359 integer specifying a debug level (normally 0 or 1, but 2 means more
7360 debugging info for the mips target).
7362 * DEC Alpha native support
7364 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7365 debug info, but GDB works fairly well with the DEC compiler and should
7366 work with a future GCC release. See the README file for a few
7367 Alpha-specific notes.
7369 * Preliminary thread implementation
7371 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7373 * LynxOS native and target support for 386
7375 This release has been hosted on LynxOS 2.2, and also can be configured
7376 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7379 * Improvements in C++ mangling/demangling.
7381 This release has much better g++ debugging, specifically in name
7382 mangling/demangling, virtual function calls, print virtual table,
7383 call methods, ...etc.
7385 *** Changes in GDB-4.10:
7387 * User visible changes:
7389 Remote debugging using the GDB-specific (`target remote') protocol now
7390 supports the `load' command. This is only useful if you have some
7391 other way of getting the stub to the target system, and you can put it
7392 somewhere in memory where it won't get clobbered by the download.
7394 Filename completion now works.
7396 When run under emacs mode, the "info line" command now causes the
7397 arrow to point to the line specified. Also, "info line" prints
7398 addresses in symbolic form (as well as hex).
7400 All vxworks based targets now support a user settable option, called
7401 vxworks-timeout. This option represents the number of seconds gdb
7402 should wait for responses to rpc's. You might want to use this if
7403 your vxworks target is, perhaps, a slow software simulator or happens
7404 to be on the far side of a thin network line.
7408 This release contains support for using a DEC alpha as a GDB host for
7409 cross debugging. Native alpha debugging is not supported yet.
7412 *** Changes in GDB-4.9:
7416 This is the first GDB release which is accompanied by a matching testsuite.
7417 The testsuite requires installation of dejagnu, which should be available
7418 via ftp from most sites that carry GNU software.
7422 'Cfront' style demangling has had its name changed to 'ARM' style, to
7423 emphasize that it was written from the specifications in the C++ Annotated
7424 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7425 disclaimers, it still generated too much confusion with users attempting to
7426 use gdb with AT&T cfront.
7430 GDB now uses a standard remote interface to a simulator library.
7431 So far, the library contains simulators for the Zilog Z8001/2, the
7432 Hitachi H8/300, H8/500 and Super-H.
7434 * New targets supported
7436 H8/300 simulator h8300-hitachi-hms or h8300hms
7437 H8/500 simulator h8500-hitachi-hms or h8500hms
7438 SH simulator sh-hitachi-hms or sh
7439 Z8000 simulator z8k-zilog-none or z8ksim
7440 IDT MIPS board over serial line mips-idt-ecoff
7442 Cross-debugging to GO32 targets is supported. It requires a custom
7443 version of the i386-stub.c module which is integrated with the
7444 GO32 memory extender.
7446 * New remote protocols
7448 MIPS remote debugging protocol.
7450 * New source languages supported
7452 This version includes preliminary support for Chill, a Pascal like language
7453 used by telecommunications companies. Chill support is also being integrated
7454 into the GNU compiler, but we don't know when it will be publically available.
7457 *** Changes in GDB-4.8:
7459 * HP Precision Architecture supported
7461 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7462 version of this support was available as a set of patches from the
7463 University of Utah. GDB does not support debugging of programs
7464 compiled with the HP compiler, because HP will not document their file
7465 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7466 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7468 Many problems in the preliminary version have been fixed.
7470 * Faster and better demangling
7472 We have improved template demangling and fixed numerous bugs in the GNU style
7473 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7474 character types (wchar_t) are now supported. Demangling of each symbol is now
7475 only done once, and is cached when the symbol table for a file is read in.
7476 This results in a small increase in memory usage for C programs, a moderate
7477 increase in memory usage for C++ programs, and a fantastic speedup in
7480 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7481 from the specifications in the Annotated Reference Manual, which AT&T's
7482 compiler does not actually implement.
7484 * G++ multiple inheritance compiler problem
7486 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7487 inheritance lattices was reworked to properly discover ambiguities. We
7488 recently found an example which causes this new algorithm to fail in a
7489 very subtle way, producing bad debug information for those classes.
7490 The file 'gcc.patch' (in this directory) can be applied to gcc to
7491 circumvent the problem. A future GCC release will contain a complete
7494 The previous G++ debug info problem (mentioned below for the gdb-4.7
7495 release) is fixed in gcc version 2.3.2.
7497 * Improved configure script
7499 The `configure' script will now attempt to guess your system type if
7500 you don't supply a host system type. The old scheme of supplying a
7501 host system triplet is preferable over using this. All the magic is
7502 done in the new `config.guess' script. Examine it for details.
7504 We have also brought our configure script much more in line with the FSF's
7505 version. It now supports the --with-xxx options. In particular,
7506 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7507 The resulting GDB will not be able to read arbitrary object file formats --
7508 only the format ``expected'' to be used on the configured target system.
7509 We hope to make this the default in a future release.
7511 * Documentation improvements
7513 There's new internal documentation on how to modify GDB, and how to
7514 produce clean changes to the code. We implore people to read it
7515 before submitting changes.
7517 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7518 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7519 `info' files are also provided. To build `info' files from scratch,
7520 you will need the latest `makeinfo' release, which will be available in
7521 a future texinfo-X.Y release.
7523 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7524 We're not sure exactly which versions have this problem, but it has
7525 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7526 or better. If that isn't possible, there is a patch in
7527 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7528 around this problem.
7532 GDB now supports array constants that can be used in expressions typed in by
7533 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7534 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7537 The new directory `gdb/sparclite' contains a program that demonstrates
7538 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7540 * New native hosts supported
7542 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7543 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7545 * New targets supported
7547 AMD 29k family via UDI a29k-amd-udi or udi29k
7549 * New file formats supported
7551 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7552 HPUX core files, and SCO 3.2v2 core files.
7556 Attaching to processes now works again; thanks for the many bug reports.
7558 We have also stomped on a bunch of core dumps caused by
7559 printf_filtered("%s") problems.
7561 We eliminated a copyright problem on the rpc and ptrace header files
7562 for VxWorks, which was discovered at the last minute during the 4.7
7563 release. You should now be able to build a VxWorks GDB.
7565 You can now interrupt gdb while an attached process is running. This
7566 will cause the attached process to stop, and give control back to GDB.
7568 We fixed problems caused by using too many file descriptors
7569 for reading symbols from object files and libraries. This was
7570 especially a problem for programs that used many (~100) shared
7573 The `step' command now only enters a subroutine if there is line number
7574 information for the subroutine. Otherwise it acts like the `next'
7575 command. Previously, `step' would enter subroutines if there was
7576 any debugging information about the routine. This avoids problems
7577 when using `cc -g1' on MIPS machines.
7579 * Internal improvements
7581 GDB's internal interfaces have been improved to make it easier to support
7582 debugging of multiple languages in the future.
7584 GDB now uses a common structure for symbol information internally.
7585 Minimal symbols (derived from linkage symbols in object files), partial
7586 symbols (from a quick scan of debug information), and full symbols
7587 contain a common subset of information, making it easier to write
7588 shared code that handles any of them.
7590 * New command line options
7592 We now accept --silent as an alias for --quiet.
7596 The memory-mapped-malloc library is now licensed under the GNU Library
7597 General Public License.
7599 *** Changes in GDB-4.7:
7601 * Host/native/target split
7603 GDB has had some major internal surgery to untangle the support for
7604 hosts and remote targets. Now, when you configure GDB for a remote
7605 target, it will no longer load in all of the support for debugging
7606 local programs on the host. When fully completed and tested, this will
7607 ensure that arbitrary host/target combinations are possible.
7609 The primary conceptual shift is to separate the non-portable code in
7610 GDB into three categories. Host specific code is required any time GDB
7611 is compiled on that host, regardless of the target. Target specific
7612 code relates to the peculiarities of the target, but can be compiled on
7613 any host. Native specific code is everything else: it can only be
7614 built when the host and target are the same system. Child process
7615 handling and core file support are two common `native' examples.
7617 GDB's use of /proc for controlling Unix child processes is now cleaner.
7618 It has been split out into a single module under the `target_ops' vector,
7619 plus two native-dependent functions for each system that uses /proc.
7621 * New hosts supported
7623 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7624 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7625 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7627 * New targets supported
7629 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7630 68030 and CPU32 m68030-*-*, m68332-*-*
7632 * New native hosts supported
7634 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7635 (386bsd is not well tested yet)
7636 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7638 * New file formats supported
7640 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7641 supports reading of `a.out.adobe' object files, which are an a.out
7642 format extended with minimal information about multiple sections.
7646 `show copying' is the same as the old `info copying'.
7647 `show warranty' is the same as `info warrantee'.
7648 These were renamed for consistency. The old commands continue to work.
7650 `info handle' is a new alias for `info signals'.
7652 You can now define pre-command hooks, which attach arbitrary command
7653 scripts to any command. The commands in the hook will be executed
7654 prior to the user's command. You can also create a hook which will be
7655 executed whenever the program stops. See gdb.texinfo.
7659 We now deal with Cfront style name mangling, and can even extract type
7660 info from mangled symbols. GDB can automatically figure out which
7661 symbol mangling style your C++ compiler uses.
7663 Calling of methods and virtual functions has been improved as well.
7667 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7668 fixed. This was due to mishandling of the extra N_SO stabs output
7671 We also finally got Ultrix 4.2 running in house, and fixed core file
7672 support, with help from a dozen people on the net.
7674 John M. Farrell discovered that the reason that single-stepping was so
7675 slow on all of the Mips based platforms (primarily SGI and DEC) was
7676 that we were trying to demangle and lookup a symbol used for internal
7677 purposes on every instruction that was being stepped through. Changing
7678 the name of that symbol so that it couldn't be mistaken for a C++
7679 mangled symbol sped things up a great deal.
7681 Rich Pixley sped up symbol lookups in general by getting much smarter
7682 about when C++ symbol mangling is necessary. This should make symbol
7683 completion (TAB on the command line) much faster. It's not as fast as
7684 we'd like, but it's significantly faster than gdb-4.6.
7688 A new user controllable variable 'call_scratch_address' can
7689 specify the location of a scratch area to be used when GDB
7690 calls a function in the target. This is necessary because the
7691 usual method of putting the scratch area on the stack does not work
7692 in systems that have separate instruction and data spaces.
7694 We integrated changes to support the 29k UDI (Universal Debugger
7695 Interface), but discovered at the last minute that we didn't have all
7696 of the appropriate copyright paperwork. We are working with AMD to
7697 resolve this, and hope to have it available soon.
7701 We have sped up the remote serial line protocol, especially for targets
7702 with lots of registers. It now supports a new `expedited status' ('T')
7703 message which can be used in place of the existing 'S' status message.
7704 This allows the remote stub to send only the registers that GDB
7705 needs to make a quick decision about single-stepping or conditional
7706 breakpoints, eliminating the need to fetch the entire register set for
7707 each instruction being stepped through.
7709 The GDB remote serial protocol now implements a write-through cache for
7710 registers, only re-reading the registers if the target has run.
7712 There is also a new remote serial stub for SPARC processors. You can
7713 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7714 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7715 processor with a serial port.
7719 Configure.in files have become much easier to read and modify. A new
7720 `table driven' format makes it more obvious what configurations are
7721 supported, and what files each one uses.
7725 There is a new opcodes library which will eventually contain all of the
7726 disassembly routines and opcode tables. At present, it only contains
7727 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7728 disassembler (binutils/objdump) to share these routines.
7730 The libiberty library is now copylefted under the GNU Library General
7731 Public License. This allows more liberal use, and was done so libg++
7732 can use it. This makes no difference to GDB, since the Library License
7733 grants all the rights from the General Public License.
7737 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7738 reference to the stabs symbol info used by the debugger. It is (as far
7739 as we know) the only published document on this fascinating topic. We
7740 encourage you to read it, compare it to the stabs information on your
7741 system, and send improvements on the document in general (to
7742 bug-gdb@prep.ai.mit.edu).
7744 And, of course, many bugs have been fixed.
7747 *** Changes in GDB-4.6:
7749 * Better support for C++ function names
7751 GDB now accepts as input the "demangled form" of C++ overloaded function
7752 names and member function names, and can do command completion on such names
7753 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7754 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7755 Make use of command completion, it is your friend.
7757 GDB also now accepts a variety of C++ mangled symbol formats. They are
7758 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7759 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7760 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7761 for the list of formats.
7763 * G++ symbol mangling problem
7765 Recent versions of gcc have a bug in how they emit debugging information for
7766 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7767 directory) can be applied to gcc to fix the problem. Alternatively, if you
7768 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7769 usual symptom is difficulty with setting breakpoints on methods. GDB complains
7770 about the method being non-existent. (We believe that version 2.2.2 of GCC has
7773 * New 'maintenance' command
7775 All of the commands related to hacking GDB internals have been moved out of
7776 the main command set, and now live behind the 'maintenance' command. This
7777 can also be abbreviated as 'mt'. The following changes were made:
7779 dump-me -> maintenance dump-me
7780 info all-breakpoints -> maintenance info breakpoints
7781 printmsyms -> maintenance print msyms
7782 printobjfiles -> maintenance print objfiles
7783 printpsyms -> maintenance print psymbols
7784 printsyms -> maintenance print symbols
7786 The following commands are new:
7788 maintenance demangle Call internal GDB demangler routine to
7789 demangle a C++ link name and prints the result.
7790 maintenance print type Print a type chain for a given symbol
7792 * Change to .gdbinit file processing
7794 We now read the $HOME/.gdbinit file before processing the argv arguments
7795 (e.g. reading symbol files or core files). This allows global parameters to
7796 be set, which will apply during the symbol reading. The ./.gdbinit is still
7797 read after argv processing.
7799 * New hosts supported
7801 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
7803 GNU/Linux support i386-unknown-linux or linux
7805 We are also including code to support the HP/PA running BSD and HPUX. This
7806 is almost guaranteed not to work, as we didn't have time to test or build it
7807 for this release. We are including it so that the more adventurous (or
7808 masochistic) of you can play with it. We also had major problems with the
7809 fact that the compiler that we got from HP doesn't support the -g option.
7812 * New targets supported
7814 Hitachi H8/300 h8300-hitachi-hms or h8300hms
7816 * More smarts about finding #include files
7818 GDB now remembers the compilation directory for all include files, and for
7819 all files from which C is generated (like yacc and lex sources). This
7820 greatly improves GDB's ability to find yacc/lex sources, and include files,
7821 especially if you are debugging your program from a directory different from
7822 the one that contains your sources.
7824 We also fixed a bug which caused difficulty with listing and setting
7825 breakpoints in include files which contain C code. (In the past, you had to
7826 try twice in order to list an include file that you hadn't looked at before.)
7828 * Interesting infernals change
7830 GDB now deals with arbitrary numbers of sections, where the symbols for each
7831 section must be relocated relative to that section's landing place in the
7832 target's address space. This work was needed to support ELF with embedded
7833 stabs used by Solaris-2.0.
7835 * Bug fixes (of course!)
7837 There have been loads of fixes for the following things:
7838 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
7839 i960, stabs, DOS(GO32), procfs, etc...
7841 See the ChangeLog for details.
7843 *** Changes in GDB-4.5:
7845 * New machines supported (host and target)
7847 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
7849 SGI Irix-4.x mips-sgi-irix4 or iris4
7851 * New malloc package
7853 GDB now uses a new memory manager called mmalloc, based on gmalloc.
7854 Mmalloc is capable of handling multiple heaps of memory. It is also
7855 capable of saving a heap to a file, and then mapping it back in later.
7856 This can be used to greatly speedup the startup of GDB by using a
7857 pre-parsed symbol table which lives in a mmalloc managed heap. For
7858 more details, please read mmalloc/mmalloc.texi.
7862 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
7863 'help info proc' for details.
7865 * MIPS ecoff symbol table format
7867 The code that reads MIPS symbol table format is now supported on all hosts.
7868 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
7871 * File name changes for MS-DOS
7873 Many files in the config directories have been renamed to make it easier to
7874 support GDB on MS-DOSe systems (which have very restrictive file name
7875 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
7876 environment) is close to working but has some remaining problems. Note
7877 that debugging of DOS programs is not supported, due to limitations
7878 in the ``operating system'', but it can be used to host cross-debugging.
7880 * Cross byte order fixes
7882 Many fixes have been made to support cross debugging of Sparc and MIPS
7883 targets from hosts whose byte order differs.
7885 * New -mapped and -readnow options
7887 If memory-mapped files are available on your system through the 'mmap'
7888 system call, you can use the -mapped option on the `file' or
7889 `symbol-file' commands to cause GDB to write the symbols from your
7890 program into a reusable file. If the program you are debugging is
7891 called `/path/fred', the mapped symbol file will be `./fred.syms'.
7892 Future GDB debugging sessions will notice the presence of this file,
7893 and will quickly map in symbol information from it, rather than reading
7894 the symbol table from the executable program. Using the '-mapped'
7895 option in a GDB `file' or `symbol-file' command has the same effect as
7896 starting GDB with the '-mapped' command-line option.
7898 You can cause GDB to read the entire symbol table immediately by using
7899 the '-readnow' option with any of the commands that load symbol table
7900 information (or on the GDB command line). This makes the command
7901 slower, but makes future operations faster.
7903 The -mapped and -readnow options are typically combined in order to
7904 build a `fred.syms' file that contains complete symbol information.
7905 A simple GDB invocation to do nothing but build a `.syms' file for future
7908 gdb -batch -nx -mapped -readnow programname
7910 The `.syms' file is specific to the host machine on which GDB is run.
7911 It holds an exact image of GDB's internal symbol table. It cannot be
7912 shared across multiple host platforms.
7914 * longjmp() handling
7916 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
7917 siglongjmp() without losing control. This feature has not yet been ported to
7918 all systems. It currently works on many 386 platforms, all MIPS-based
7919 platforms (SGI, DECstation, etc), and Sun3/4.
7923 Preliminary work has been put in to support the new Solaris OS from Sun. At
7924 this time, it can control and debug processes, but it is not capable of
7929 As always, many many bug fixes. The major areas were with g++, and mipsread.
7930 People using the MIPS-based platforms should experience fewer mysterious
7931 crashes and trashed symbol tables.
7933 *** Changes in GDB-4.4:
7935 * New machines supported (host and target)
7937 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
7939 BSD Reno on Vax vax-dec-bsd
7940 Ultrix on Vax vax-dec-ultrix
7942 * New machines supported (target)
7944 AMD 29000 embedded, using EBMON a29k-none-none
7948 GDB continues to improve its handling of C++. `References' work better.
7949 The demangler has also been improved, and now deals with symbols mangled as
7950 per the Annotated C++ Reference Guide.
7952 GDB also now handles `stabs' symbol information embedded in MIPS
7953 `ecoff' symbol tables. Since the ecoff format was not easily
7954 extensible to handle new languages such as C++, this appeared to be a
7955 good way to put C++ debugging info into MIPS binaries. This option
7956 will be supported in the GNU C compiler, version 2, when it is
7959 * New features for SVR4
7961 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
7962 shared libraries. Debugging dynamically linked programs should present
7963 only minor differences from debugging statically linked programs.
7965 The `info proc' command will print out information about any process
7966 on an SVR4 system (including the one you are debugging). At the moment,
7967 it prints the address mappings of the process.
7969 If you bring up GDB on another SVR4 system, please send mail to
7970 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
7972 * Better dynamic linking support in SunOS
7974 Reading symbols from shared libraries which contain debugging symbols
7975 now works properly. However, there remain issues such as automatic
7976 skipping of `transfer vector' code during function calls, which
7977 make it harder to debug code in a shared library, than to debug the
7978 same code linked statically.
7982 GDB is now using the latest `getopt' routines from the FSF. This
7983 version accepts the -- prefix for options with long names. GDB will
7984 continue to accept the old forms (-option and +option) as well.
7985 Various single letter abbreviations for options have been explicity
7986 added to the option table so that they won't get overshadowed in the
7987 future by other options that begin with the same letter.
7991 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
7992 Many assorted bugs have been handled. Many more remain to be handled.
7993 See the various ChangeLog files (primarily in gdb and bfd) for details.
7996 *** Changes in GDB-4.3:
7998 * New machines supported (host and target)
8000 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8001 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8002 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8004 * Almost SCO Unix support
8006 We had hoped to support:
8007 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8008 (except for core file support), but we discovered very late in the release
8009 that it has problems with process groups that render gdb unusable. Sorry
8010 about that. I encourage people to fix it and post the fixes.
8012 * Preliminary ELF and DWARF support
8014 GDB can read ELF object files on System V Release 4, and can handle
8015 debugging records for C, in DWARF format, in ELF files. This support
8016 is preliminary. If you bring up GDB on another SVR4 system, please
8017 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8022 GDB now uses the latest `readline' library. One user-visible change
8023 is that two tabs will list possible command completions, which previously
8024 required typing M-? (meta-question mark, or ESC ?).
8028 The `stepi' bug that many of you noticed has been squashed.
8029 Many bugs in C++ have been handled. Many more remain to be handled.
8030 See the various ChangeLog files (primarily in gdb and bfd) for details.
8032 * State of the MIPS world (in case you wondered):
8034 GDB can understand the symbol tables emitted by the compilers
8035 supplied by most vendors of MIPS-based machines, including DEC. These
8036 symbol tables are in a format that essentially nobody else uses.
8038 Some versions of gcc come with an assembler post-processor called
8039 mips-tfile. This program is required if you want to do source-level
8040 debugging of gcc-compiled programs. I believe FSF does not ship
8041 mips-tfile with gcc version 1, but it will eventually come with gcc
8044 Debugging of g++ output remains a problem. g++ version 1.xx does not
8045 really support it at all. (If you're lucky, you should be able to get
8046 line numbers and stack traces to work, but no parameters or local
8047 variables.) With some work it should be possible to improve the
8050 When gcc version 2 is released, you will have somewhat better luck.
8051 However, even then you will get confusing results for inheritance and
8054 We will eventually provide full debugging of g++ output on
8055 DECstations. This will probably involve some kind of stabs-in-ecoff
8056 encapulation, but the details have not been worked out yet.
8059 *** Changes in GDB-4.2:
8061 * Improved configuration
8063 Only one copy of `configure' exists now, and it is not self-modifying.
8064 Porting BFD is simpler.
8068 The `step' and `next' commands now only stop at the first instruction
8069 of a source line. This prevents the multiple stops that used to occur
8070 in switch statements, for-loops, etc. `Step' continues to stop if a
8071 function that has debugging information is called within the line.
8075 Lots of small bugs fixed. More remain.
8077 * New host supported (not target)
8079 Intel 386 PC clone running Mach i386-none-mach
8082 *** Changes in GDB-4.1:
8084 * Multiple source language support
8086 GDB now has internal scaffolding to handle several source languages.
8087 It determines the type of each source file from its filename extension,
8088 and will switch expression parsing and number formatting to match the
8089 language of the function in the currently selected stack frame.
8090 You can also specifically set the language to be used, with
8091 `set language c' or `set language modula-2'.
8095 GDB now has preliminary support for the GNU Modula-2 compiler,
8096 currently under development at the State University of New York at
8097 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8098 continue through the fall of 1991 and into 1992.
8100 Other Modula-2 compilers are currently not supported, and attempting to
8101 debug programs compiled with them will likely result in an error as the
8102 symbol table is read. Feel free to work on it, though!
8104 There are hooks in GDB for strict type checking and range checking,
8105 in the `Modula-2 philosophy', but they do not currently work.
8109 GDB can now write to executable and core files (e.g. patch
8110 a variable's value). You must turn this switch on, specify
8111 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8112 by assigning a new value to a variable. Modifications take
8115 * Automatic SunOS shared library reading
8117 When you run your program, GDB automatically determines where its
8118 shared libraries (if any) have been loaded, and reads their symbols.
8119 The `share' command is no longer needed. This also works when
8120 examining core files.
8124 You can specify the number of lines that the `list' command shows.
8127 * New machines supported (host and target)
8129 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8130 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8131 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8133 * New hosts supported (not targets)
8135 IBM RT/PC: romp-ibm-aix or rtpc
8137 * New targets supported (not hosts)
8139 AMD 29000 embedded with COFF a29k-none-coff
8140 AMD 29000 embedded with a.out a29k-none-aout
8141 Ultracomputer remote kernel debug a29k-nyu-kern
8143 * New remote interfaces
8149 *** Changes in GDB-4.0:
8153 Wide output is wrapped at good places to make the output more readable.
8155 Gdb now supports cross-debugging from a host machine of one type to a
8156 target machine of another type. Communication with the target system
8157 is over serial lines. The ``target'' command handles connecting to the
8158 remote system; the ``load'' command will download a program into the
8159 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8160 also supports debugging of realtime processes running under VxWorks,
8161 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8162 stub on the target system.
8164 New CPUs supported include the AMD 29000 and Intel 960.
8166 GDB now reads object files and symbol tables via a ``binary file''
8167 library, which allows a single copy of GDB to debug programs of multiple
8168 object file types such as a.out and coff.
8170 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8171 refcard.dvi and refcard.ps are available to format it).
8174 * Control-Variable user interface simplified
8176 All variables that control the operation of the debugger can be set
8177 by the ``set'' command, and displayed by the ``show'' command.
8179 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8180 ``Show prompt'' produces the response:
8181 Gdb's prompt is new-gdb=>.
8183 What follows are the NEW set commands. The command ``help set'' will
8184 print a complete list of old and new set commands. ``help set FOO''
8185 will give a longer description of the variable FOO. ``show'' will show
8186 all of the variable descriptions and their current settings.
8188 confirm on/off: Enables warning questions for operations that are
8189 hard to recover from, e.g. rerunning the program while
8190 it is already running. Default is ON.
8192 editing on/off: Enables EMACS style command line editing
8193 of input. Previous lines can be recalled with
8194 control-P, the current line can be edited with control-B,
8195 you can search for commands with control-R, etc.
8198 history filename NAME: NAME is where the gdb command history
8199 will be stored. The default is .gdb_history,
8200 or the value of the environment variable
8203 history size N: The size, in commands, of the command history. The
8204 default is 256, or the value of the environment variable
8207 history save on/off: If this value is set to ON, the history file will
8208 be saved after exiting gdb. If set to OFF, the
8209 file will not be saved. The default is OFF.
8211 history expansion on/off: If this value is set to ON, then csh-like
8212 history expansion will be performed on
8213 command line input. The default is OFF.
8215 radix N: Sets the default radix for input and output. It can be set
8216 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8217 in the current radix, so "set radix 10" is always a no-op.
8219 height N: This integer value is the number of lines on a page. Default
8220 is 24, the current `stty rows'' setting, or the ``li#''
8221 setting from the termcap entry matching the environment
8224 width N: This integer value is the number of characters on a line.
8225 Default is 80, the current `stty cols'' setting, or the ``co#''
8226 setting from the termcap entry matching the environment
8229 Note: ``set screensize'' is obsolete. Use ``set height'' and
8230 ``set width'' instead.
8232 print address on/off: Print memory addresses in various command displays,
8233 such as stack traces and structure values. Gdb looks
8234 more ``symbolic'' if you turn this off; it looks more
8235 ``machine level'' with it on. Default is ON.
8237 print array on/off: Prettyprint arrays. New convenient format! Default
8240 print demangle on/off: Print C++ symbols in "source" form if on,
8243 print asm-demangle on/off: Same, for assembler level printouts
8246 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8249 * Support for Epoch Environment.
8251 The epoch environment is a version of Emacs v18 with windowing. One
8252 new command, ``inspect'', is identical to ``print'', except that if you
8253 are running in the epoch environment, the value is printed in its own
8257 * Support for Shared Libraries
8259 GDB can now debug programs and core files that use SunOS shared libraries.
8260 Symbols from a shared library cannot be referenced
8261 before the shared library has been linked with the program (this
8262 happens after you type ``run'' and before the function main() is entered).
8263 At any time after this linking (including when examining core files
8264 from dynamically linked programs), gdb reads the symbols from each
8265 shared library when you type the ``sharedlibrary'' command.
8266 It can be abbreviated ``share''.
8268 sharedlibrary REGEXP: Load shared object library symbols for files
8269 matching a unix regular expression. No argument
8270 indicates to load symbols for all shared libraries.
8272 info sharedlibrary: Status of loaded shared libraries.
8277 A watchpoint stops execution of a program whenever the value of an
8278 expression changes. Checking for this slows down execution
8279 tremendously whenever you are in the scope of the expression, but is
8280 quite useful for catching tough ``bit-spreader'' or pointer misuse
8281 problems. Some machines such as the 386 have hardware for doing this
8282 more quickly, and future versions of gdb will use this hardware.
8284 watch EXP: Set a watchpoint (breakpoint) for an expression.
8286 info watchpoints: Information about your watchpoints.
8288 delete N: Deletes watchpoint number N (same as breakpoints).
8289 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8290 enable N: Re-enables watchpoint number N (same as breakpoints).
8293 * C++ multiple inheritance
8295 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8298 * C++ exception handling
8300 Gdb now supports limited C++ exception handling. Besides the existing
8301 ability to breakpoint on an exception handler, gdb can breakpoint on
8302 the raising of an exception (before the stack is peeled back to the
8305 catch FOO: If there is a FOO exception handler in the dynamic scope,
8306 set a breakpoint to catch exceptions which may be raised there.
8307 Multiple exceptions (``catch foo bar baz'') may be caught.
8309 info catch: Lists all exceptions which may be caught in the
8310 current stack frame.
8313 * Minor command changes
8315 The command ``call func (arg, arg, ...)'' now acts like the print
8316 command, except it does not print or save a value if the function's result
8317 is void. This is similar to dbx usage.
8319 The ``up'' and ``down'' commands now always print the frame they end up
8320 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8321 frames without printing.
8323 * New directory command
8325 'dir' now adds directories to the FRONT of the source search path.
8326 The path starts off empty. Source files that contain debug information
8327 about the directory in which they were compiled can be found even
8328 with an empty path; Sun CC and GCC include this information. If GDB can't
8329 find your source file in the current directory, type "dir .".
8331 * Configuring GDB for compilation
8333 For normal use, type ``./configure host''. See README or gdb.texinfo
8336 GDB now handles cross debugging. If you are remotely debugging between
8337 two different machines, type ``./configure host -target=targ''.
8338 Host is the machine where GDB will run; targ is the machine
8339 where the program that you are debugging will run.