1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 12
6 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
8 * Remove support for building against Python 2, it is now only possible to
9 build GDB against Python 3.
11 * DBX mode has been removed.
13 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
14 emit to indicate where a breakpoint should be placed to break in a function
19 maintenance set ignore-prologue-end-flag on|off
20 maintenance show ignore-prologue-end-flag
21 This setting, which is off by default, controls whether GDB ignores the
22 PROLOGUE-END flag from the line-table when skipping prologue. This can be
23 used to force GDB to use prologue analyzers if the line-table is constructed
24 from erroneous debug information.
28 maintenance info line-table
29 Add a PROLOGUE-END column to the output which indicates that an
30 entry corresponds to an address where a breakpoint should be placed
31 to be at the first instruction past a function's prologue.
35 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
36 that formats ADDRESS as 'address <symbol+offset>', where symbol is
37 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
38 This is the same format that GDB uses when printing address, symbol,
39 and offset information from the disassembler.
43 * DBX mode is deprecated, and will be removed in GDB 13
45 * GDB 12 is the last release of GDB that will support building against
46 Python 2. From GDB 13, it will only be possible to build GDB itself
47 with Python 3 support.
49 * Improved C++ template support
51 GDB now treats functions/types involving C++ templates like it does function
52 overloads. Users may omit parameter lists to set breakpoints on families of
53 template functions, including types/functions composed of multiple template types:
55 (gdb) break template_func(template_1, int)
57 The above will set breakpoints at every function `template_func' where
58 the first function parameter is any template type named `template_1' and
59 the second function parameter is `int'.
61 TAB completion also gains similar improvements.
63 * The FreeBSD native target now supports async mode.
69 Enable or disable multithreaded symbol loading. This is enabled
70 by default, but passing --disable-threading or --enable-threading=no
71 to configure will disable it.
73 Disabling this can cause a performance penalty when there are a lot of
74 symbols to load, but is useful for debugging purposes.
78 maint set backtrace-on-fatal-signal on|off
79 maint show backtrace-on-fatal-signal
80 This setting is 'on' by default. When 'on' GDB will print a limited
81 backtrace to stderr in the situation where GDB terminates with a
82 fatal signal. This only supported on some platforms where the
83 backtrace and backtrace_symbols_fd functions are available.
85 set source open on|off
87 This setting, which is on by default, controls whether GDB will try
88 to open source code files. Switching this off will stop GDB trying
89 to open and read source code files, which can be useful if the files
90 are located over a slow network connection.
94 These are now deprecated aliases for "set max-value-size" and
95 "show max-value-size".
97 task apply [all | TASK-IDS...] [FLAG]... COMMAND
98 Like "thread apply", but applies COMMAND to Ada tasks.
101 Watchpoints can now be restricted to a specific Ada task.
103 maint set internal-error backtrace on|off
104 maint show internal-error backtrace
105 maint set internal-warning backtrace on|off
106 maint show internal-warning backtrace
107 GDB can now print a backtrace of itself when it encounters either an
108 internal-error, or an internal-warning. This is on by default for
109 internal-error and off by default for internal-warning.
112 Deprecated and replaced by "set logging enabled on|off".
114 set logging enabled on|off
116 These commands set or show whether logging is enabled or disabled.
119 You can now exit GDB by using the new command "exit", in addition to
120 the existing "quit" command.
122 set debug threads on|off
124 Print additional debug messages about thread creation and deletion.
126 set debug linux-nat on|off
128 These new commands replaced the old 'set debug lin-lwp' and 'show
129 debug lin-lwp' respectively. Turning this setting on prints debug
130 messages relating to GDB's handling of native Linux inferiors.
132 maint flush source-cache
133 Flush the contents of the source code cache.
135 maint set gnu-source-highlight enabled on|off
136 maint show gnu-source-highlight enabled
137 Whether GDB should use the GNU Source Highlight library for adding
138 styling to source code. When off, the library will not be used, even
139 when available. When GNU Source Highlight isn't used, or can't add
140 styling to a particular source file, then the Python Pygments
141 library will be used instead.
143 set suppress-cli-notifications (on|off)
144 show suppress-cli-notifications
145 This controls whether printing the notifications is suppressed for CLI.
146 CLI notifications occur when you change the selected context
147 (i.e., the current inferior, thread and/or the frame), or when
148 the program being debugged stops (e.g., because of hitting a
149 breakpoint, completing source-stepping, an interrupt, etc.).
151 set style disassembler enabled on|off
152 show style disassembler enabled
153 If GDB is compiled with Python support, and the Python Pygments
154 package is available, then, when this setting is on, disassembler
155 output will have styling applied.
157 set ada source-charset
158 show ada source-charset
159 Set the character set encoding that is assumed for Ada symbols. Valid
160 values for this follow the values that can be passed to the GNAT
161 compiler via the '-gnati' option. The default is ISO-8859-1.
167 These are the new names for the old 'layout', 'focus', 'refresh',
168 and 'winheight' tui commands respectively. The old names still
169 exist as aliases to these new commands.
173 The new command 'tui window width', and the alias 'winwidth' allow
174 the width of a tui window to be adjusted when windows are laid out
179 Control the display of debug output about GDB's tui.
184 Printing of floating-point values with base-modifying formats like
185 /x has been changed to display the underlying bytes of the value in
186 the desired base. This was GDB's documented behavior, but was never
187 implemented correctly.
190 This command can now print a reply, if the reply includes
191 non-printable characters. Any non-printable characters are printed
192 as escaped hex, e.g. \x?? where '??' is replaces with the value of
193 the non-printable character.
196 The clone-inferior command now ensures that the TTY, CMD and ARGS
197 settings are copied from the original inferior to the new one.
198 All modifications to the environment variables done using the 'set
199 environment' or 'unset environment' commands are also copied to the new
202 set debug lin-lwp on|off
204 These commands have been removed from GDB. The new command 'set
205 debug linux-nat' and 'show debug linux-nat' should be used
209 This command now includes information about the width of the tui
210 windows in its output.
216 These commands are now aliases for the 'tui layout', 'tui focus',
217 'tui refresh', and 'tui window height' commands respectively.
219 * GDB's Ada parser now supports an extension for specifying the exact
220 byte contents of a floating-point literal. This can be useful for
221 setting floating-point registers to a precise value without loss of
222 precision. The syntax is an extension of the based literal syntax.
223 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
224 of the floating-point type, and the "f" is the marker for floating
229 ** The '-add-inferior' with no option flags now inherits the
230 connection of the current inferior, this restores the behaviour of
231 GDB as it was prior to GDB 10.
233 ** The '-add-inferior' command now accepts a '--no-connection'
234 option, which causes the new inferior to start without a
239 GNU/Linux/LoongArch loongarch*-*-linux*
247 ** New function gdb.add_history(), which takes a gdb.Value object
248 and adds the value it represents to GDB's history list. An
249 integer, the index of the new item in the history list, is
252 ** New function gdb.history_count(), which returns the number of
253 values in GDB's value history.
255 ** New gdb.events.gdb_exiting event. This event is called with a
256 gdb.GdbExitingEvent object which has the read-only attribute
257 'exit_code', which contains the value of the GDB exit code. This
258 event is triggered once GDB decides it is going to exit, but
259 before GDB starts to clean up its internal state.
261 ** New function gdb.architecture_names(), which returns a list
262 containing all of the possible Architecture.name() values. Each
265 ** New function gdb.Architecture.integer_type(), which returns an
266 integer type given a size and a signed-ness.
268 ** New gdb.TargetConnection object type that represents a connection
269 (as displayed by the 'info connections' command). A sub-class,
270 gdb.RemoteTargetConnection, is used to represent 'remote' and
271 'extended-remote' connections.
273 ** The gdb.Inferior type now has a 'connection' property which is an
274 instance of gdb.TargetConnection, the connection used by this
275 inferior. This can be None if the inferior has no connection.
277 ** New 'gdb.events.connection_removed' event registry, which emits a
278 'gdb.ConnectionEvent' when a connection is removed from GDB.
279 This event has a 'connection' property, a gdb.TargetConnection
280 object for the connection being removed.
282 ** New gdb.connections() function that returns a list of all
283 currently active connections.
285 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
286 is equivalent to the existing 'maint packet' CLI command; it
287 allows a user specified packet to be sent to the remote target.
289 ** New function gdb.host_charset(), returns a string, which is the
290 name of the current host charset.
292 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
295 ** New gdb.with_parameter(NAME, VALUE). This returns a context
296 manager that temporarily sets the gdb parameter NAME to VALUE,
297 then resets it when the context is exited.
299 ** The gdb.Value.format_string method now takes a 'styling'
300 argument, which is a boolean. When true, the returned string can
301 include escape sequences to apply styling. The styling will only
302 be present if styling is otherwise turned on in GDB (see 'help
303 set styling'). When false, which is the default if the argument
304 is not given, then no styling is applied to the returned string.
306 ** New read-only attribute gdb.InferiorThread.details, which is
307 either a string, containing additional, target specific thread
308 state information, or None, if there is no such additional
311 ** New read-only attribute gdb.Type.is_scalar, which is True for
312 scalar types, and False for all other types.
314 ** New read-only attribute gdb.Type.is_signed. This attribute
315 should only be read when Type.is_scalar is True, and will be True
316 for signed types, and False for all other types. Attempting to
317 read this attribute for non-scalar types will raise a ValueError.
319 ** It is now possible to add GDB/MI commands implemented in Python.
321 * New features in the GDB remote stub, GDBserver
323 ** GDBserver is now supported on OpenRISC GNU/Linux.
325 * New native configurations
327 GNU/Linux/OpenRISC or1k*-*-linux*
329 *** Changes in GDB 11
331 * The 'set disassembler-options' command now supports specifying options
334 * GDB now supports general memory tagging functionality if the underlying
335 architecture supports the proper primitives and hooks. Currently this is
336 enabled only for AArch64 MTE.
340 - Additional information when the inferior crashes with a SIGSEGV caused by
341 a memory tag violation.
343 - A new modifier 'm' for the "x" command, which displays allocation tags for a
344 particular memory range.
346 - Display of memory tag mismatches by "print", for addresses and
347 pointers, if memory tagging is supported by the architecture.
349 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
354 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
356 The MI -break-insert and -dprintf-insert commands now support a
357 new "--qualified" option that makes GDB interpret a specified
358 function name as a complete fully-qualified name. This is the
359 equivalent of the CLI's "break -qualified" and "dprintf
362 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
364 The MI -break-insert and -dprintf-insert commands now support a
365 '--force-condition' flag to forcibly define a condition even when
366 the condition is invalid at all locations of the breakpoint. This
367 is equivalent to the '-force-condition' flag of the CLI's "break"
370 ** '-break-condition --force'
372 The MI -break-condition command now supports a '--force' flag to
373 forcibly define a condition even when the condition is invalid at
374 all locations of the selected breakpoint. This is equivalent to
375 the '-force' flag of the CLI's "cond" command.
377 ** '-file-list-exec-source-files [--group-by-objfile]
378 [--basename | --dirname]
381 The existing -file-list-exec-source-files command now takes an
382 optional REGEXP which is used to filter the source files that are
383 included in the results.
385 By default REGEXP is matched against the full filename of the
386 source file. When one of --basename or --dirname is given then
387 REGEXP is only matched against the specified part of the full
390 When the optional --group-by-objfile flag is used the output
391 format is changed, the results are now a list of object files
392 (executable and libraries) with the source files that are
393 associated with each object file.
395 The results from -file-list-exec-source-files now include a
396 'debug-fully-read' field which takes the value 'true' or 'false'.
397 A 'true' value indicates the source file is from a compilation
398 unit that has had its debug information fully read in by GDB, a
399 value of 'false' indicates GDB has only performed a partial scan
400 of the debug information so far.
402 * GDB now supports core file debugging for x86_64 Cygwin programs.
404 * GDB will now look for the .gdbinit file in a config directory before
405 looking for ~/.gdbinit. The file is searched for in the following
406 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
407 $HOME/.gdbinit. On Apple hosts the search order is instead:
408 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
410 * GDB now supports fixed point types which are described in DWARF
411 as base types with a fixed-point encoding. Additionally, support
412 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
415 For Ada, this allows support for fixed point types without requiring
416 the use of the GNAT encoding (based on information added to the type's
417 name following a GNAT-specific format).
419 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
420 or ~/.gdbearlyinit if these files are present. These files are
421 processed earlier than any of the other initialization files and
422 can affect parts of GDB's startup that previously had already been
423 completed before the initialization files were read, for example
424 styling of the initial GDB greeting.
426 * GDB now has two new options "--early-init-command" and
427 "--early-init-eval-command" with corresponding short options "-eix"
428 and "-eiex" that allow options (that would normally appear in a
429 gdbearlyinit file) to be passed on the command line.
431 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
432 now understood by GDB, and can be used to describe the vector
433 registers of a target. The precise requirements of this register
434 feature are documented in the GDB manual.
436 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
437 supported by GDB and describes a new VPR register from the ARM MVE
438 (Helium) extension. See the GDB manual for more information.
442 ** TUI windows now support mouse actions. The mouse wheel scrolls
443 the appropriate window.
445 ** Key combinations that do not have a specific action on the
446 focused window are passed to GDB. For example, you now can use
447 Ctrl-Left/Ctrl-Right to move between words in the command window
448 regardless of which window is in focus. Previously you would
449 need to focus on the command window for such key combinations to
455 show debug event-loop
456 Control the display of debug output about GDB's event loop.
458 set print memory-tag-violations
459 show print memory-tag-violations
460 Control whether to display additional information about memory tag violations
461 when printing pointers and addresses. Architecture support for memory
462 tagging is required for this option to have an effect.
464 maintenance flush symbol-cache
465 maintenance flush register-cache
466 These new commands are equivalent to the already existing commands
467 'maintenance flush-symbol-cache' and 'flushregs' respectively.
469 maintenance flush dcache
470 A new command to flush the dcache.
472 maintenance info target-sections
473 Print GDB's internal target sections table.
476 Print the JIT code objects in the inferior known to GDB.
478 memory-tag show-logical-tag POINTER
479 Print the logical tag for POINTER.
480 memory-tag with-logical-tag POINTER TAG
481 Print POINTER with logical tag TAG.
482 memory-tag show-allocation-tag ADDRESS
483 Print the allocation tag for ADDRESS.
484 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
485 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
486 memory-tag check POINTER
487 Validate that POINTER's logical tag matches the allocation tag.
489 set startup-quietly on|off
491 When 'on', this causes GDB to act as if "-silent" were passed on the
492 command line. This command needs to be added to an early
493 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
496 set print type hex on|off
498 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
499 and offsets of struct members. When 'off', decimal notation is used.
501 set python ignore-environment on|off
502 show python ignore-environment
503 When 'on', this causes GDB's builtin Python to ignore any
504 environment variables that would otherwise affect how Python
505 behaves. This command needs to be added to an early initialization
506 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
508 set python dont-write-bytecode auto|on|off
509 show python dont-write-bytecode
510 When 'on', this causes GDB's builtin Python to not write any
511 byte-code (.pyc files) to disk. This command needs to be added to
512 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
513 order to affect GDB. When 'off' byte-code will always be written.
514 When set to 'auto' (the default) Python will check the
515 PYTHONDONTWRITEBYTECODE environment variable.
519 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
520 [-force-condition] [if CONDITION]
521 This command would previously refuse setting a breakpoint if the
522 CONDITION expression is invalid at a location. It now accepts and
523 defines the breakpoint if there is at least one location at which
524 the CONDITION is valid. The locations for which the CONDITION is
525 invalid, are automatically disabled. If CONDITION is invalid at all
526 of the locations, setting the breakpoint is still rejected. However,
527 the '-force-condition' flag can be used in this case for forcing GDB to
528 define the breakpoint, making all the current locations automatically
529 disabled. This may be useful if the user knows the condition will
530 become meaningful at a future location, e.g. due to a shared library
533 condition [-force] N COND
534 The behavior of this command is changed the same way for the 'break'
535 command as explained above. The '-force' flag can be used to force
536 GDB into defining the condition even when COND is invalid for all the
537 current locations of breakpoint N.
540 maintenance flush-symbol-cache
541 These commands are deprecated in favor of the new commands
542 'maintenance flush register-cache' and 'maintenance flush
543 symbol-cache' respectively.
545 set style version foreground COLOR
546 set style version background COLOR
547 set style version intensity VALUE
548 Control the styling of GDB's version number text.
551 When the ID parameter is omitted, then this command prints information
552 about the current inferior. When the ID parameter is present, the
553 behavior of the command is unchanged and have the inferior ID become
554 the current inferior.
556 maintenance info sections
557 The ALLOBJ keyword has been replaced with an -all-objects command
558 line flag. It is now possible to filter which sections are printed
559 even when -all-objects is passed.
561 ptype[/FLAGS] TYPE | EXPRESSION
562 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
563 notation is used when printing sizes and offsets of struct members.
564 When '/d' is set, decimal notation is used when printing sizes and
565 offsets of struct members. Default behavior is given by 'show print
569 The info sources command output has been restructured. The results
570 are now based around a list of objfiles (executable and libraries),
571 and for each objfile the source files that are part of that objfile
574 * Removed targets and native configurations
576 ARM Symbian arm*-*-symbianelf*
581 Request the remote to send allocation tags for a particular memory range.
583 Request the remote to store the specified allocation tags to the requested
588 ** Improved support for rvalue reference values:
589 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
590 value-referenced-value procedure now handles rvalue reference
593 ** New procedures for obtaining value variants:
594 value-reference-value, value-rvalue-reference-value and
597 ** Temporary breakpoints can now be created with make-breakpoint and
598 tested for using breakpoint-temporary?.
602 ** Inferior objects now contain a read-only 'connection_num' attribute that
603 gives the connection number as seen in 'info connections' and
606 ** New method gdb.Frame.level() which returns the stack level of the
609 ** New method gdb.PendingFrame.level() which returns the stack level
612 ** When hitting a catchpoint, the Python API will now emit a
613 gdb.BreakpointEvent rather than a gdb.StopEvent. The
614 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
616 ** Python TUI windows can now receive mouse click events. If the
617 Window object implements the click method, it is called for each
618 mouse click event in this window.
620 *** Changes in GDB 10
622 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
623 and "org.gnu.gdb.arc.aux". The old names are still supported but
624 must be considered obsolete. They will be deprecated after some
627 * Help and apropos commands will now show the documentation of a
628 command only once, even if that command has one or more aliases.
629 These commands now show the command name, then all of its aliases,
630 and finally the description of the command.
632 * 'help aliases' now shows only the user defined aliases. GDB predefined
633 aliases are shown together with their aliased command.
635 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
636 debugging information as well as source code.
638 When built with debuginfod, GDB can automatically query debuginfod
639 servers for the separate debug files and source code of the executable
642 To build GDB with debuginfod, pass --with-debuginfod to configure (this
643 requires libdebuginfod, the debuginfod client library).
645 debuginfod is distributed with elfutils, starting with version 0.178.
647 You can get the latest version from https://sourceware.org/elfutils.
649 * Multi-target debugging support
651 GDB now supports debugging multiple target connections
652 simultaneously. For example, you can now have each inferior
653 connected to different remote servers running in different machines,
654 or have one inferior debugging a local native process, an inferior
655 debugging a core dump, etc.
657 This support is experimental and comes with some limitations -- you
658 can only resume multiple targets simultaneously if all targets
659 support non-stop mode, and all remote stubs or servers must support
660 the same set of remote protocol features exactly. See also "info
661 connections" and "add-inferior -no-connection" below, and "maint set
662 target-non-stop" in the user manual.
664 * New features in the GDB remote stub, GDBserver
666 ** GDBserver is now supported on ARC GNU/Linux.
668 ** GDBserver is now supported on RISC-V GNU/Linux.
670 ** GDBserver no longer supports these host triplets:
681 i[34567]86-*-mingw32ce*
683 * Debugging MS-Windows processes now sets $_exitsignal when the
684 inferior is terminated by a signal, instead of setting $_exitcode.
686 * Multithreaded symbol loading has now been enabled by default on systems
687 that support it (see entry for GDB 9, below), providing faster
688 performance for programs with many symbols.
690 * The $_siginfo convenience variable now also works on Windows targets,
691 and will display the EXCEPTION_RECORD of the last handled exception.
693 * TUI windows can now be arranged horizontally.
695 * The command history filename can now be set to the empty string
696 either using 'set history filename' or by setting 'GDBHISTFILE=' in
697 the environment. The effect of setting this filename to the empty
698 string is that GDB will not try to load any previous command
701 * On Windows targets, it is now possible to debug 32-bit programs with a
706 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
707 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
708 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
709 running process, this new option indicates whether to detect
710 a mismatch between the current executable file loaded by GDB and the
711 executable file used to start the process. If 'ask', the default,
712 display a warning and ask the user whether to load the process
713 executable file; if 'warn', just display a warning; if 'off', don't
714 attempt to detect a mismatch.
716 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
717 Define a new TUI layout, specifying its name and the windows that
720 maintenance print xml-tdesc [FILE]
721 Prints the current target description as an XML document. If the
722 optional FILE is provided (which is an XML target description) then
723 the target description is read from FILE into GDB, and then
726 maintenance print core-file-backed-mappings
727 Prints file-backed mappings loaded from a core file's note section.
728 Output is expected to be similar to that of "info proc mappings".
730 set debug fortran-array-slicing on|off
731 show debug fortran-array-slicing
732 Print debugging when taking slices of Fortran arrays.
734 set fortran repack-array-slices on|off
735 show fortran repack-array-slices
736 When taking slices from Fortran arrays and strings, if the slice is
737 non-contiguous within the original value then, when this option is
738 on, the new value will be repacked into a single contiguous value.
739 When this option is off, then the value returned will consist of a
740 descriptor that describes the slice within the memory of the
741 original parent value.
745 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
746 The alias command can now specify default args for an alias.
747 GDB automatically prepends the alias default args to the argument list
748 provided explicitly by the user.
749 For example, to have a backtrace with full details, you can define
751 'alias bt_ALL = backtrace -entry-values both -frame-arg all
752 -past-main -past-entry -full'.
753 Alias default arguments can also use a set of nested 'with' commands,
754 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
755 defines the alias pp10 that will pretty print a maximum of 10 elements
756 of the given expression (if the expression is an array).
760 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
766 ** gdb.register_window_type can be used to implement new TUI windows
769 ** Dynamic types can now be queried. gdb.Type has a new attribute,
770 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
771 field of a dynamic type may have None for its "bitpos" attribute
774 ** Commands written in Python can be in the "TUI" help class by
775 registering with the new constant gdb.COMMAND_TUI.
777 ** New method gdb.PendingFrame.architecture () to retrieve the
778 architecture of the pending frame.
780 ** New gdb.Architecture.registers method that returns a
781 gdb.RegisterDescriptorIterator object, an iterator that returns
782 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
783 way to query the registers available for an architecture.
785 ** New gdb.Architecture.register_groups method that returns a
786 gdb.RegisterGroupIterator object, an iterator that returns
787 gdb.RegisterGroup objects. The new RegisterGroup is a way to
788 discover the available register groups.
792 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
794 ** Procedures 'memory-port-read-buffer-size',
795 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
796 and 'set-memory-port-write-buffer-size!' are deprecated. When
797 using Guile 2.2 and later, users who need to control the size of
798 a memory port's internal buffer can use the 'setvbuf' procedure.
802 * 'thread-exited' event is now available in the annotations interface.
804 * New built-in convenience variables $_gdb_major and $_gdb_minor
805 provide the GDB version. They are handy for conditionally using
806 features available only in or since specific GDB versions, in
807 scripts that should work error-free with many different versions,
808 such as in system-wide init files.
810 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
811 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
812 of the GDB settings and the GDB maintenance settings. They are handy
813 for changing the logic of user defined commands depending on the
814 current GDB settings.
816 * GDB now supports Thread Local Storage (TLS) variables on several
817 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
818 architectures require kernel changes. TLS is not yet supported for
819 amd64 and i386 process core dumps.
821 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
822 addresses that required unmasking are shown in the backtrace with the
825 * Two new convenience functions $_cimag and $_creal that extract the
826 imaginary and real parts respectively from complex numbers.
828 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
829 provide the exitcode or exit status of the shell commands launched by
830 GDB commands such as "shell", "pipe" and "make".
832 * The command define-prefix can now define user defined prefix commands.
833 User defined commands can now be defined using these user defined prefix
836 * Command names can now use the . character.
838 * The RX port now supports XML target descriptions.
840 * GDB now shows the Ada task names at more places, e.g. in task switching
843 * GDB can now be compiled with Python 3 on Windows.
845 * New convenience variable $_ada_exception holds the address of the
846 Ada exception being thrown. This is set by Ada-related catchpoints.
848 * GDB can now place breakpoints on nested functions and subroutines in
849 Fortran code. The '::' operator can be used between parent and
850 child scopes when placing breakpoints, for example:
852 (gdb) break outer_function::inner_function
854 The 'outer_function::' prefix is only needed if 'inner_function' is
855 not visible in the current scope.
857 * In addition to the system-wide gdbinit file, if configured with
858 --with-system-gdbinit-dir, GDB will now also load files in that directory
859 as system gdbinit files, unless the -nx or -n flag is provided. Files
860 with extensions .gdb, .py and .scm are supported as long as GDB was
861 compiled with support for that language.
863 * GDB now supports multithreaded symbol loading for higher performance.
864 This feature is still in testing, so it is disabled by default. You
865 can turn it on using 'maint set worker-threads unlimited'.
869 ** The gdb.Value type has a new method 'format_string' which returns a
870 string representing the value. The formatting is controlled by the
871 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
872 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
873 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
875 ** gdb.Type has a new property 'objfile' which returns the objfile the
878 ** The frame information printed by the python frame filtering code
879 is now consistent with what the 'backtrace' command prints when
880 there are no filters, or when the 'backtrace' '-no-filters' option
883 ** The new function gdb.lookup_static_symbol can be used to look up
884 symbols with static linkage.
886 ** The new function gdb.lookup_static_symbols can be used to look up
887 all static symbols with static linkage.
889 ** gdb.Objfile has new methods 'lookup_global_symbol' and
890 'lookup_static_symbol' to lookup a symbol from this objfile only.
892 ** gdb.Block now supports the dictionary syntax for accessing symbols in
893 this block (e.g. block['local_variable']).
897 | [COMMAND] | SHELL_COMMAND
898 | -d DELIM COMMAND DELIM SHELL_COMMAND
899 pipe [COMMAND] | SHELL_COMMAND
900 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
901 Executes COMMAND and sends its output to SHELL_COMMAND.
902 With no COMMAND, repeat the last executed command
903 and send its output to SHELL_COMMAND.
905 define-prefix COMMAND
906 Define or mark a command as a user-defined prefix command.
908 with SETTING [VALUE] [-- COMMAND]
909 w SETTING [VALUE] [-- COMMAND]
910 Temporarily set SETTING, run COMMAND, and restore SETTING.
911 Usage: with SETTING -- COMMAND
912 With no COMMAND, repeats the last executed command.
913 SETTING is any GDB setting you can change with the "set"
914 subcommands. For example, 'with language c -- print someobj'
915 temporarily switches to the C language in order to print someobj.
916 Settings can be combined: 'w lang c -- w print elements unlimited --
917 usercmd' switches to the C language and runs usercmd with no limit
918 of array elements to print.
920 maint with SETTING [VALUE] [-- COMMAND]
921 Like "with", but works with "maintenance set" settings.
923 set may-call-functions [on|off]
924 show may-call-functions
925 This controls whether GDB will attempt to call functions in
926 the program, such as with expressions in the print command. It
927 defaults to on. Calling functions in the program being debugged
928 can have undesired side effects. It is now possible to forbid
929 such function calls. If function calls are forbidden, GDB will throw
930 an error when a command (such as print expression) calls a function
933 set print finish [on|off]
935 This controls whether the `finish' command will display the value
936 that is returned by the current function. When `off', the value is
937 still entered into the value history, but it is not printed. The
942 Allows deeply nested structures to be simplified when printing by
943 replacing deeply nested parts (beyond the max-depth) with ellipses.
944 The default max-depth is 20, but this can be set to unlimited to get
945 the old behavior back.
947 set print raw-values [on|off]
948 show print raw-values
949 By default, GDB applies the enabled pretty printers when printing a
950 value. This allows to ignore the enabled pretty printers for a series
951 of commands. The default is 'off'.
953 set logging debugredirect [on|off]
954 By default, GDB debug output will go to both the terminal and the logfile.
955 Set if you want debug output to go only to the log file.
957 set style title foreground COLOR
958 set style title background COLOR
959 set style title intensity VALUE
960 Control the styling of titles.
962 set style highlight foreground COLOR
963 set style highlight background COLOR
964 set style highlight intensity VALUE
965 Control the styling of highlightings.
967 maint set worker-threads
968 maint show worker-threads
969 Control the number of worker threads that can be used by GDB. The
970 default is 0. "unlimited" lets GDB choose a number that is
971 reasonable. Currently worker threads are only used when demangling
972 the names of linker symbols.
974 set style tui-border foreground COLOR
975 set style tui-border background COLOR
976 Control the styling of TUI borders.
978 set style tui-active-border foreground COLOR
979 set style tui-active-border background COLOR
980 Control the styling of the active TUI border.
982 maint set test-settings KIND
983 maint show test-settings KIND
984 A set of commands used by the testsuite for exercising the settings
987 maint set tui-resize-message [on|off]
988 maint show tui-resize-message
989 Control whether GDB prints a message each time the terminal is
990 resized when in TUI mode. This is primarily useful for testing the
993 set print frame-info [short-location|location|location-and-address
994 |source-and-location|source-line|auto]
995 show print frame-info
996 This controls what frame information is printed by the commands printing
997 a frame. This setting will e.g. influence the behaviour of 'backtrace',
998 'frame', 'stepi'. The python frame filtering also respect this setting.
999 The 'backtrace' '-frame-info' option can override this global setting.
1001 set tui compact-source
1002 show tui compact-source
1004 Enable the "compact" display mode for the TUI source window. The
1005 compact display uses only as much space as is needed for the line
1006 numbers in the current file, and only a single space to separate the
1007 line numbers from the source.
1009 info modules [-q] [REGEXP]
1010 Return a list of Fortran modules matching REGEXP, or all modules if
1013 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1014 Return a list of functions within all modules, grouped by module.
1015 The list of functions can be restricted with the optional regular
1016 expressions. MODULE_REGEXP matches against the module name,
1017 TYPE_REGEXP matches against the function type signature, and REGEXP
1018 matches against the function name.
1020 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1021 Return a list of variables within all modules, grouped by module.
1022 The list of variables can be restricted with the optional regular
1023 expressions. MODULE_REGEXP matches against the module name,
1024 TYPE_REGEXP matches against the variable type, and REGEXP matches
1025 against the variable name.
1027 set debug remote-packet-max-chars
1028 show debug remote-packet-max-chars
1029 Controls the number of characters to output in a remote packet when using
1031 The default is 512 bytes.
1034 Lists the target connections currently in use.
1039 The "help" command uses the title style to enhance the
1040 readibility of its output by styling the classes and
1044 Similarly to "help", the "apropos" command also uses the
1045 title style for the command names. "apropos" accepts now
1046 a flag "-v" (verbose) to show the full documentation
1047 of matching commands and to use the highlight style to mark
1048 the documentation parts matching REGEXP.
1052 The GDB printf and eval commands can now print C-style and Ada-style
1053 string convenience variables without calling functions in the program.
1054 This allows to do formatted printing of strings without having
1055 a running inferior, or when debugging a core dump.
1057 info sources [-dirname | -basename] [--] [REGEXP]
1058 This command has now optional arguments to only print the files
1059 whose names match REGEXP. The arguments -dirname and -basename
1060 allow to restrict matching respectively to the dirname and basename
1064 The "show style" and its subcommands are now styling
1065 a style name in their output using its own style, to help
1066 the user visualize the different styles.
1068 set print frame-arguments
1069 The new value 'presence' indicates to only indicate the presence of
1070 arguments using ..., instead of printing argument names and values.
1072 set print raw-frame-arguments
1073 show print raw-frame-arguments
1075 These commands replace the similarly-named "set/show print raw
1076 frame-arguments" commands (now with a dash instead of a space). The
1077 old commands are now deprecated and may be removed in a future
1080 add-inferior [-no-connection]
1081 The add-inferior command now supports a "-no-connection" flag that
1082 makes the new inferior start with no target connection associated.
1083 By default, the new inferior inherits the target connection of the
1084 current inferior. See also "info connections".
1087 This command's output now includes a new "Connection" column
1088 indicating which target connection an inferior is bound to. See
1089 "info connections" above.
1091 maint test-options require-delimiter
1092 maint test-options unknown-is-error
1093 maint test-options unknown-is-operand
1094 maint show test-options-completion-result
1095 Commands used by the testsuite to validate the command options
1098 focus, winheight, +, -, >, <
1099 These commands are now case-sensitive.
1101 * New command options, command completion
1103 GDB now has a standard infrastructure to support dash-style command
1104 options ('-OPT'). One benefit is that commands that use it can
1105 easily support completion of command line arguments. Try "CMD
1106 -[TAB]" or "help CMD" to find options supported by a command. Over
1107 time, we intend to migrate most commands to this infrastructure. A
1108 number of commands got support for new command options in this
1111 ** The "print" and "compile print" commands now support a number of
1112 options that allow overriding relevant global print settings as
1113 set by "set print" subcommands:
1117 -array-indexes [on|off]
1118 -elements NUMBER|unlimited
1122 -raw-values [on|off]
1123 -repeats NUMBER|unlimited
1124 -static-members [on|off]
1129 Note that because the "print"/"compile print" commands accept
1130 arbitrary expressions which may look like options (including
1131 abbreviations), if you specify any command option, then you must
1132 use a double dash ("--") to mark the end of argument processing.
1134 ** The "backtrace" command now supports a number of options that
1135 allow overriding relevant global print settings as set by "set
1136 backtrace" and "set print" subcommands:
1138 -entry-values no|only|preferred|if-needed|both|compact|default
1139 -frame-arguments all|scalars|none
1140 -raw-frame-arguments [on|off]
1141 -frame-info auto|source-line|location|source-and-location
1142 |location-and-address|short-location
1144 -past-entry [on|off]
1146 In addition, the full/no-filters/hide qualifiers are now also
1147 exposed as command options too:
1153 ** The "frame apply", "tfaas" and "faas" commands similarly now
1154 support the following options:
1157 -past-entry [on|off]
1159 ** The new "info sources" options -dirname and -basename options
1160 are using the standard '-OPT' infrastructure.
1162 All options above can also be abbreviated. The argument of boolean
1163 (on/off) options can be 0/1 too, and also the argument is assumed
1164 "on" if omitted. This allows writing compact command invocations,
1167 (gdb) p -ra -p -o 0 -- *myptr
1169 The above is equivalent to:
1171 (gdb) print -raw-values -pretty -object off -- *myptr
1173 ** The "info types" command now supports the '-q' flag to disable
1174 printing of some header information in a similar fashion to "info
1175 variables" and "info functions".
1177 ** The "info variables", "info functions", and "whereis" commands
1178 now take a '-n' flag that excludes non-debug symbols (symbols
1179 from the symbol table, not from the debug info such as DWARF)
1182 * Completion improvements
1184 ** GDB can now complete the options of the "thread apply all" and
1185 "taas" commands, and their "-ascending" option can now be
1188 ** GDB can now complete the options of the "info threads", "info
1189 functions", "info variables", "info locals", and "info args"
1192 ** GDB can now complete the options of the "compile file" and
1193 "compile code" commands. The "compile file" command now
1194 completes on filenames.
1196 ** GDB can now complete the backtrace command's
1197 "full/no-filters/hide" qualifiers.
1199 * In settings, you can now abbreviate "unlimited".
1201 E.g., "set print elements u" is now equivalent to "set print
1202 elements unlimited".
1207 This lists all the possible completions for the rest of the line, if it
1208 were to be given as a command itself. This is intended for use by MI
1209 frontends in cases when separate CLI and MI channels cannot be used.
1211 -catch-throw, -catch-rethrow, and -catch-catch
1212 These can be used to catch C++ exceptions in a similar fashion to
1213 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1215 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1216 These commands are the MI equivalent of the CLI commands 'info
1217 functions', 'info types', and 'info variables' respectively.
1219 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1222 -symbol-info-module-functions and -symbol-info-module-variables.
1223 These commands are the MI equivalent of the CLI commands 'info
1224 module functions' and 'info module variables'.
1228 ** The default version of the MI interpreter is now 3 (-i=mi3).
1230 ** The output of information about multi-location breakpoints (which is
1231 syntactically incorrect in MI 2) has changed in MI 3. This affects
1232 the following commands and events:
1236 - =breakpoint-created
1237 - =breakpoint-modified
1239 The -fix-multi-location-breakpoint-output command can be used to enable
1240 this behavior with previous MI versions.
1242 ** Backtraces and frames include a new optional field addr_flags which is
1243 given after the addr field. On AArch64 this contains PAC if the address
1244 has been masked in the frame. On all other targets the field is not
1249 The testsuite now creates the files gdb.cmd (containing the arguments
1250 used to launch GDB) and gdb.in (containing all the commands sent to
1251 GDB) in the output directory for each test script. Multiple invocations
1252 are appended with .1, .2, .3 etc.
1254 * Building GDB and GDBserver now requires GNU make >= 3.82.
1256 Using another implementation of the make program or an earlier version of
1257 GNU make to build GDB or GDBserver is not supported.
1259 * Building GDB now requires GNU readline >= 7.0.
1261 GDB now bundles GNU readline 8.0, but if you choose to use
1262 --with-system-readline, only readline >= 7.0 can be used.
1264 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1265 from .inputrc to bind keys in this keymap. This feature is only
1266 available when gdb is built against GNU readline 8.0 or later.
1268 * Removed targets and native configurations
1270 GDB no longer supports debugging the Cell Broadband Engine. This includes
1271 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1272 of Cell/B.E. applications that use both the PPU and SPU architectures.
1278 * Removed targets and native configurations
1280 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1281 sparc*-*-solaris2.10
1283 *** Changes in GDB 8.3
1285 * GDB and GDBserver now support access to additional registers on
1286 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1289 * GDB now has experimental support for the compilation and injection of
1290 C++ source code into the inferior. This beta release does not include
1291 support for several language features, such as templates, constructors,
1294 This feature requires GCC 7.1 or higher built with libcp1.so
1297 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1298 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1299 'ADDRESS:PORT' method.
1301 * DWARF index cache: GDB can now automatically save indices of DWARF
1302 symbols on disk to speed up further loading of the same binaries.
1304 * Ada task switching is now supported on aarch64-elf targets when
1305 debugging a program using the Ravenscar Profile. For more information,
1306 see the "Tasking Support when using the Ravenscar Profile" section
1307 in the GDB user manual.
1309 * GDB in batch mode now exits with status 1 if the last command to be
1312 * The RISC-V target now supports target descriptions.
1314 * System call catchpoints now support system call aliases on FreeBSD.
1315 When the ABI of a system call changes in FreeBSD, this is
1316 implemented by leaving a compatibility system call using the old ABI
1317 at the existing number and allocating a new system call number for
1318 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1319 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1320 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1321 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1322 so that a system call catchpoint for the 'kevent' system call will
1323 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1324 binaries. This ensures that 'kevent' system calls are caught for
1325 binaries using either the old or new ABIs.
1327 * Terminal styling is now available for the CLI and the TUI. GNU
1328 Source Highlight can additionally be used to provide styling of
1329 source code snippets. See the "set style" commands, below, for more
1332 * Removed support for old demangling styles arm, edg, gnu, hp and
1337 set debug compile-cplus-types
1338 show debug compile-cplus-types
1339 Control the display of debug output about type conversion in the
1340 C++ compile feature. Commands have no effect while compiling
1341 for other languages.
1345 Control whether debug output about files/functions skipping is
1348 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1349 Apply a command to some frames.
1350 FLAG arguments allow to control what output to produce and how to handle
1351 errors raised when applying COMMAND to a frame.
1354 Apply a command to all threads (ignoring errors and empty output).
1355 Shortcut for 'thread apply all -s COMMAND'.
1358 Apply a command to all frames (ignoring errors and empty output).
1359 Shortcut for 'frame apply all -s COMMAND'.
1362 Apply a command to all frames of all threads (ignoring errors and empty
1364 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1366 maint set dwarf unwinders (on|off)
1367 maint show dwarf unwinders
1368 Control whether DWARF unwinders can be used.
1371 Display a list of open files for a process.
1375 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1376 These commands all now take a frame specification which
1377 is either a frame level, or one of the keywords 'level', 'address',
1378 'function', or 'view' followed by a parameter. Selecting a frame by
1379 address, or viewing a frame outside the current backtrace now
1380 requires the use of a keyword. Selecting a frame by level is
1381 unchanged. The MI comment "-stack-select-frame" is unchanged.
1383 target remote FILENAME
1384 target extended-remote FILENAME
1385 If FILENAME is a Unix domain socket, GDB will attempt to connect
1386 to this socket instead of opening FILENAME as a character device.
1388 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1389 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1390 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1391 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1392 These commands can now print only the searched entities
1393 matching the provided regexp(s), giving a condition
1394 on the entity names or entity types. The flag -q disables
1395 printing headers or informations messages.
1401 These commands now determine the syntax for the shown entities
1402 according to the language chosen by `set language'. In particular,
1403 `set language auto' means to automatically choose the language of
1406 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1407 The 'thread apply' command accepts new FLAG arguments.
1408 FLAG arguments allow to control what output to produce and how to handle
1409 errors raised when applying COMMAND to a thread.
1411 set tui tab-width NCHARS
1412 show tui tab-width NCHARS
1413 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1415 set style enabled [on|off]
1417 Enable or disable terminal styling. Styling is enabled by default
1418 on most hosts, but disabled by default when in batch mode.
1420 set style sources [on|off]
1422 Enable or disable source code styling. Source code styling is
1423 enabled by default, but only takes effect if styling in general is
1424 enabled, and if GDB was linked with GNU Source Highlight.
1426 set style filename foreground COLOR
1427 set style filename background COLOR
1428 set style filename intensity VALUE
1429 Control the styling of file names.
1431 set style function foreground COLOR
1432 set style function background COLOR
1433 set style function intensity VALUE
1434 Control the styling of function names.
1436 set style variable foreground COLOR
1437 set style variable background COLOR
1438 set style variable intensity VALUE
1439 Control the styling of variable names.
1441 set style address foreground COLOR
1442 set style address background COLOR
1443 set style address intensity VALUE
1444 Control the styling of addresses.
1448 ** The '-data-disassemble' MI command now accepts an '-a' option to
1449 disassemble the whole function surrounding the given program
1450 counter value or function name. Support for this feature can be
1451 verified by using the "-list-features" command, which should
1452 contain "data-disassemble-a-option".
1454 ** Command responses and notifications that include a frame now include
1455 the frame's architecture in a new "arch" attribute.
1457 * New native configurations
1459 GNU/Linux/RISC-V riscv*-*-linux*
1460 FreeBSD/riscv riscv*-*-freebsd*
1464 GNU/Linux/RISC-V riscv*-*-linux*
1465 CSKY ELF csky*-*-elf
1466 CSKY GNU/LINUX csky*-*-linux
1467 FreeBSD/riscv riscv*-*-freebsd*
1469 GNU/Linux/OpenRISC or1k*-*-linux*
1473 GDB no longer supports native debugging on versions of MS-Windows
1478 ** GDB no longer supports Python versions less than 2.6.
1480 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1481 space associated to that inferior.
1483 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1484 of objfiles associated to that program space.
1486 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1487 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1490 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1491 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1492 correct and did not work properly.
1494 ** The gdb.Value type has a new constructor, which is used to construct a
1495 gdb.Value from a Python buffer object and a gdb.Type.
1501 Enable or disable the undefined behavior sanitizer. This is
1502 disabled by default, but passing --enable-ubsan=yes or
1503 --enable-ubsan=auto to configure will enable it. Enabling this can
1504 cause a performance penalty. The undefined behavior sanitizer was
1505 first introduced in GCC 4.9.
1507 *** Changes in GDB 8.2
1509 * The 'set disassembler-options' command now supports specifying options
1510 for the MIPS target.
1512 * The 'symbol-file' command now accepts an '-o' option to add a relative
1513 offset to all sections.
1515 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1516 a relative offset to all sections, but it allows to override the load
1517 address of individual sections using '-s'.
1519 * The 'add-symbol-file' command no longer requires the second argument
1520 (address of the text section).
1522 * The endianness used with the 'set endian auto' mode in the absence of
1523 an executable selected for debugging is now the last endianness chosen
1524 either by one of the 'set endian big' and 'set endian little' commands
1525 or by inferring from the last executable used, rather than the startup
1528 * The pager now allows a "c" response, meaning to disable the pager
1529 for the rest of the current command.
1531 * The commands 'info variables/functions/types' now show the source line
1532 numbers of symbol definitions when available.
1534 * 'info proc' now works on running processes on FreeBSD systems and core
1535 files created on FreeBSD systems.
1537 * C expressions can now use _Alignof, and C++ expressions can now use
1540 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1541 the vector length while the process is running.
1547 Control display of debugging info regarding the FreeBSD native target.
1549 set|show varsize-limit
1550 This new setting allows the user to control the maximum size of Ada
1551 objects being printed when those objects have a variable type,
1552 instead of that maximum size being hardcoded to 65536 bytes.
1554 set|show record btrace cpu
1555 Controls the processor to be used for enabling errata workarounds for
1556 branch trace decode.
1558 maint check libthread-db
1559 Run integrity checks on the current inferior's thread debugging
1562 maint set check-libthread-db (on|off)
1563 maint show check-libthread-db
1564 Control whether to run integrity checks on inferior specific thread
1565 debugging libraries as they are loaded. The default is not to
1566 perform such checks.
1570 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1572 ** The commands attached to a breakpoint can be set by assigning to
1573 the breakpoint's "commands" field.
1575 ** gdb.execute can now execute multi-line gdb commands.
1577 ** The new functions gdb.convenience_variable and
1578 gdb.set_convenience_variable can be used to get and set the value
1579 of convenience variables.
1581 ** A gdb.Parameter will no longer print the "set" help text on an
1582 ordinary "set"; instead by default a "set" will be silent unless
1583 the get_set_string method returns a non-empty string.
1587 RiscV ELF riscv*-*-elf
1589 * Removed targets and native configurations
1591 m88k running OpenBSD m88*-*-openbsd*
1592 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1593 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1594 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1596 * Aarch64/Linux hardware watchpoints improvements
1598 Hardware watchpoints on unaligned addresses are now properly
1599 supported when running Linux kernel 4.10 or higher: read and access
1600 watchpoints are no longer spuriously missed, and all watchpoints
1601 lengths between 1 and 8 bytes are supported. On older kernels,
1602 watchpoints set on unaligned addresses are no longer missed, with
1603 the tradeoff that there is a possibility of false hits being
1608 --enable-codesign=CERT
1609 This can be used to invoke "codesign -s CERT" after building gdb.
1610 This option is useful on macOS, where code signing is required for
1611 gdb to work properly.
1613 --disable-gdbcli has been removed
1614 This is now silently accepted, but does nothing.
1616 *** Changes in GDB 8.1
1618 * GDB now supports dynamically creating arbitrary register groups specified
1619 in XML target descriptions. This allows for finer grain grouping of
1620 registers on systems with a large amount of registers.
1622 * The 'ptype' command now accepts a '/o' flag, which prints the
1623 offsets and sizes of fields in a struct, like the pahole(1) tool.
1625 * New "--readnever" command line option instructs GDB to not read each
1626 symbol file's symbolic debug information. This makes startup faster
1627 but at the expense of not being able to perform symbolic debugging.
1628 This option is intended for use cases where symbolic debugging will
1629 not be used, e.g., when you only need to dump the debuggee's core.
1631 * GDB now uses the GNU MPFR library, if available, to emulate target
1632 floating-point arithmetic during expression evaluation when the target
1633 uses different floating-point formats than the host. At least version
1634 3.1 of GNU MPFR is required.
1636 * GDB now supports access to the guarded-storage-control registers and the
1637 software-based guarded-storage broadcast control registers on IBM z14.
1639 * On Unix systems, GDB now supports transmitting environment variables
1640 that are to be set or unset to GDBserver. These variables will
1641 affect the environment to be passed to the remote inferior.
1643 To inform GDB of environment variables that are to be transmitted to
1644 GDBserver, use the "set environment" command. Only user set
1645 environment variables are sent to GDBserver.
1647 To inform GDB of environment variables that are to be unset before
1648 the remote inferior is started by the GDBserver, use the "unset
1649 environment" command.
1651 * Completion improvements
1653 ** GDB can now complete function parameters in linespecs and
1654 explicit locations without quoting. When setting breakpoints,
1655 quoting around functions names to help with TAB-completion is
1656 generally no longer necessary. For example, this now completes
1659 (gdb) b function(in[TAB]
1660 (gdb) b function(int)
1662 Related, GDB is no longer confused with completing functions in
1663 C++ anonymous namespaces:
1666 (gdb) b (anonymous namespace)::[TAB][TAB]
1667 (anonymous namespace)::a_function()
1668 (anonymous namespace)::b_function()
1670 ** GDB now has much improved linespec and explicit locations TAB
1671 completion support, that better understands what you're
1672 completing and offers better suggestions. For example, GDB no
1673 longer offers data symbols as possible completions when you're
1674 setting a breakpoint.
1676 ** GDB now TAB-completes label symbol names.
1678 ** The "complete" command now mimics TAB completion accurately.
1680 * New command line options (gcore)
1683 Dump all memory mappings.
1685 * Breakpoints on C++ functions are now set on all scopes by default
1687 By default, breakpoints on functions/methods are now interpreted as
1688 specifying all functions with the given name ignoring missing
1689 leading scopes (namespaces and classes).
1691 For example, assuming a C++ program with symbols named:
1696 both commands "break func()" and "break B::func()" set a breakpoint
1699 You can use the new flag "-qualified" to override this. This makes
1700 GDB interpret the specified function name as a complete
1701 fully-qualified name instead. For example, using the same C++
1702 program, the "break -q B::func" command sets a breakpoint on
1703 "B::func", only. A parameter has been added to the Python
1704 gdb.Breakpoint constructor to achieve the same result when creating
1705 a breakpoint from Python.
1707 * Breakpoints on functions marked with C++ ABI tags
1709 GDB can now set breakpoints on functions marked with C++ ABI tags
1710 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1711 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1713 Functions with a C++11 abi tag are demangled/displayed like this:
1715 function[abi:cxx11](int)
1718 You can now set a breakpoint on such functions simply as if they had
1721 (gdb) b function(int)
1723 Or if you need to disambiguate between tags, like:
1725 (gdb) b function[abi:other_tag](int)
1727 Tab completion was adjusted accordingly as well.
1731 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1732 gdb.new_thread are emitted. See the manual for further
1733 description of these.
1735 ** A new function, "gdb.rbreak" has been added to the Python API.
1736 This function allows the setting of a large number of breakpoints
1737 via a regex pattern in Python. See the manual for further details.
1739 ** Python breakpoints can now accept explicit locations. See the
1740 manual for a further description of this feature.
1743 * New features in the GDB remote stub, GDBserver
1745 ** GDBserver is now able to start inferior processes with a
1746 specified initial working directory.
1748 The user can set the desired working directory to be used from
1749 GDB using the new "set cwd" command.
1751 ** New "--selftest" command line option runs some GDBserver self
1752 tests. These self tests are disabled in releases.
1754 ** On Unix systems, GDBserver now does globbing expansion and variable
1755 substitution in inferior command line arguments.
1757 This is done by starting inferiors using a shell, like GDB does.
1758 See "set startup-with-shell" in the user manual for how to disable
1759 this from GDB when using "target extended-remote". When using
1760 "target remote", you can disable the startup with shell by using the
1761 new "--no-startup-with-shell" GDBserver command line option.
1763 ** On Unix systems, GDBserver now supports receiving environment
1764 variables that are to be set or unset from GDB. These variables
1765 will affect the environment to be passed to the inferior.
1767 * When catching an Ada exception raised with a message, GDB now prints
1768 the message in the catchpoint hit notification. In GDB/MI mode, that
1769 information is provided as an extra field named "exception-message"
1770 in the *stopped notification.
1772 * Trait objects can now be inspected When debugging Rust code. This
1773 requires compiler support which will appear in Rust 1.24.
1775 * New remote packets
1777 QEnvironmentHexEncoded
1778 Inform GDBserver of an environment variable that is to be passed to
1779 the inferior when starting it.
1782 Inform GDBserver of an environment variable that is to be unset
1783 before starting the remote inferior.
1786 Inform GDBserver that the environment should be reset (i.e.,
1787 user-set environment variables should be unset).
1790 Indicates whether the inferior must be started with a shell or not.
1793 Tell GDBserver that the inferior to be started should use a specific
1796 * The "maintenance print c-tdesc" command now takes an optional
1797 argument which is the file name of XML target description.
1799 * The "maintenance selftest" command now takes an optional argument to
1800 filter the tests to be run.
1802 * The "enable", and "disable" commands now accept a range of
1803 breakpoint locations, e.g. "enable 1.3-5".
1808 Set and show the current working directory for the inferior.
1810 set|show compile-gcc
1811 Set and show compilation command used for compiling and injecting code
1812 with the 'compile' commands.
1814 set debug separate-debug-file
1815 show debug separate-debug-file
1816 Control the display of debug output about separate debug file search.
1818 set dump-excluded-mappings
1819 show dump-excluded-mappings
1820 Control whether mappings marked with the VM_DONTDUMP flag should be
1821 dumped when generating a core file.
1823 maint info selftests
1824 List the registered selftests.
1827 Start the debugged program stopping at the first instruction.
1830 Control display of debugging messages related to OpenRISC targets.
1832 set|show print type nested-type-limit
1833 Set and show the limit of nesting level for nested types that the
1834 type printer will show.
1836 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1839 * Safer/improved support for debugging with no debug info
1841 GDB no longer assumes functions with no debug information return
1844 This means that GDB now refuses to call such functions unless you
1845 tell it the function's type, by either casting the call to the
1846 declared return type, or by casting the function to a function
1847 pointer of the right type, and calling that:
1849 (gdb) p getenv ("PATH")
1850 'getenv' has unknown return type; cast the call to its declared return type
1851 (gdb) p (char *) getenv ("PATH")
1852 $1 = 0x7fffffffe "/usr/local/bin:/"...
1853 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1854 $2 = 0x7fffffffe "/usr/local/bin:/"...
1856 Similarly, GDB no longer assumes that global variables with no debug
1857 info have type 'int', and refuses to print the variable's value
1858 unless you tell it the variable's type:
1861 'var' has unknown type; cast it to its declared type
1865 * New native configurations
1867 FreeBSD/aarch64 aarch64*-*-freebsd*
1868 FreeBSD/arm arm*-*-freebsd*
1872 FreeBSD/aarch64 aarch64*-*-freebsd*
1873 FreeBSD/arm arm*-*-freebsd*
1874 OpenRISC ELF or1k*-*-elf
1876 * Removed targets and native configurations
1878 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1880 *** Changes in GDB 8.0
1882 * GDB now supports access to the PKU register on GNU/Linux. The register is
1883 added by the Memory Protection Keys for Userspace feature which will be
1884 available in future Intel CPUs.
1886 * GDB now supports C++11 rvalue references.
1890 ** New functions to start, stop and access a running btrace recording.
1891 ** Rvalue references are now supported in gdb.Type.
1893 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1896 * Building GDB and GDBserver now requires a C++11 compiler.
1898 For example, GCC 4.8 or later.
1900 It is no longer possible to build GDB or GDBserver with a C
1901 compiler. The --disable-build-with-cxx configure option has been
1904 * Building GDB and GDBserver now requires GNU make >= 3.81.
1906 It is no longer supported to build GDB or GDBserver with another
1907 implementation of the make program or an earlier version of GNU make.
1909 * Native debugging on MS-Windows supports command-line redirection
1911 Command-line arguments used for starting programs on MS-Windows can
1912 now include redirection symbols supported by native Windows shells,
1913 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1914 as "run", "start", and "set args", as well as the corresponding MI
1917 * Support for thread names on MS-Windows.
1919 GDB now catches and handles the special exception that programs
1920 running on MS-Windows use to assign names to threads in the
1923 * Support for Java programs compiled with gcj has been removed.
1925 * User commands now accept an unlimited number of arguments.
1926 Previously, only up to 10 was accepted.
1928 * The "eval" command now expands user-defined command arguments.
1930 This makes it easier to process a variable number of arguments:
1935 eval "print $arg%d", $i
1940 * Target descriptions can now describe registers for sparc32 and sparc64.
1942 * GDB now supports DWARF version 5 (debug information format).
1943 Its .debug_names index is not yet supported.
1945 * New native configurations
1947 FreeBSD/mips mips*-*-freebsd
1951 Synopsys ARC arc*-*-elf32
1952 FreeBSD/mips mips*-*-freebsd
1954 * Removed targets and native configurations
1956 Alpha running FreeBSD alpha*-*-freebsd*
1957 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1962 Erases all the flash memory regions reported by the target.
1964 maint print arc arc-instruction address
1965 Print internal disassembler information about instruction at a given address.
1969 set disassembler-options
1970 show disassembler-options
1971 Controls the passing of target specific information to the disassembler.
1972 If it is necessary to specify more than one disassembler option then
1973 multiple options can be placed together into a comma separated list.
1974 The default value is the empty string. Currently, the only supported
1975 targets are ARM, PowerPC and S/390.
1980 Erases all the flash memory regions reported by the target. This is
1981 equivalent to the CLI command flash-erase.
1983 -file-list-shared-libraries
1984 List the shared libraries in the program. This is
1985 equivalent to the CLI command "info shared".
1988 Catchpoints stopping the program when Ada exceptions are
1989 handled. This is equivalent to the CLI command "catch handlers".
1991 *** Changes in GDB 7.12
1993 * GDB and GDBserver now build with a C++ compiler by default.
1995 The --enable-build-with-cxx configure option is now enabled by
1996 default. One must now explicitly configure with
1997 --disable-build-with-cxx in order to build with a C compiler. This
1998 option will be removed in a future release.
2000 * GDBserver now supports recording btrace without maintaining an active
2003 * GDB now supports a negative repeat count in the 'x' command to examine
2004 memory backward from the given address. For example:
2007 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2008 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2009 (gdb) x/-5i 0x0000000000400580
2010 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2011 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2012 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2013 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2014 0x40057b <main(int, char**)+25>:
2015 callq 0x400536 <Func1(int, char const*)>
2017 * Fortran: Support structures with fields of dynamic types and
2018 arrays of dynamic types.
2020 * The symbol dumping maintenance commands have new syntax.
2021 maint print symbols [-pc address] [--] [filename]
2022 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2023 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2024 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2025 maint print msymbols [-objfile objfile] [--] [filename]
2027 * GDB now supports multibit bitfields and enums in target register
2030 * New Python-based convenience function $_as_string(val), which returns
2031 the textual representation of a value. This function is especially
2032 useful to obtain the text label of an enum value.
2034 * Intel MPX bound violation handling.
2036 Segmentation faults caused by a Intel MPX boundary violation
2037 now display the kind of violation (upper or lower), the memory
2038 address accessed and the memory bounds, along with the usual
2039 signal received and code location.
2043 Program received signal SIGSEGV, Segmentation fault
2044 Upper bound violation while accessing address 0x7fffffffc3b3
2045 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2046 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2048 * Rust language support.
2049 GDB now supports debugging programs written in the Rust programming
2050 language. See https://www.rust-lang.org/ for more information about
2053 * Support for running interpreters on specified input/output devices
2055 GDB now supports a new mechanism that allows frontends to provide
2056 fully featured GDB console views, as a better alternative to
2057 building such views on top of the "-interpreter-exec console"
2058 command. See the new "new-ui" command below. With that command,
2059 frontends can now start GDB in the traditional command-line mode
2060 running in an embedded terminal emulator widget, and create a
2061 separate MI interpreter running on a specified i/o device. In this
2062 way, GDB handles line editing, history, tab completion, etc. in the
2063 console all by itself, and the GUI uses the separate MI interpreter
2064 for its own control and synchronization, invisible to the command
2067 * The "catch syscall" command catches groups of related syscalls.
2069 The "catch syscall" command now supports catching a group of related
2070 syscalls using the 'group:' or 'g:' prefix.
2075 skip -gfile file-glob-pattern
2076 skip -function function
2077 skip -rfunction regular-expression
2078 A generalized form of the skip command, with new support for
2079 glob-style file names and regular expressions for function names.
2080 Additionally, a file spec and a function spec may now be combined.
2082 maint info line-table REGEXP
2083 Display the contents of GDB's internal line table data structure.
2086 Run any GDB unit tests that were compiled in.
2089 Start a new user interface instance running INTERP as interpreter,
2090 using the TTY file for input/output.
2094 ** gdb.Breakpoint objects have a new attribute "pending", which
2095 indicates whether the breakpoint is pending.
2096 ** Three new breakpoint-related events have been added:
2097 gdb.breakpoint_created, gdb.breakpoint_modified, and
2098 gdb.breakpoint_deleted.
2100 signal-event EVENTID
2101 Signal ("set") the given MS-Windows event object. This is used in
2102 conjunction with the Windows JIT debugging (AeDebug) support, where
2103 the OS suspends a crashing process until a debugger can attach to
2104 it. Resuming the crashing process, in order to debug it, is done by
2105 signalling an event.
2107 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2108 was added in GDBserver, including JIT compiling fast tracepoint's
2109 conditional expression bytecode into native code.
2111 * Support for various remote target protocols and ROM monitors has
2114 target m32rsdi Remote M32R debugging over SDI
2115 target mips MIPS remote debugging protocol
2116 target pmon PMON ROM monitor
2117 target ddb NEC's DDB variant of PMON for Vr4300
2118 target rockhopper NEC RockHopper variant of PMON
2119 target lsi LSI variant of PMO
2121 * Support for tracepoints and fast tracepoints on powerpc-linux,
2122 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2123 including JIT compiling fast tracepoint's conditional expression
2124 bytecode into native code.
2126 * MI async record =record-started now includes the method and format used for
2127 recording. For example:
2129 =record-started,thread-group="i1",method="btrace",format="bts"
2131 * MI async record =thread-selected now includes the frame field. For example:
2133 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2137 Andes NDS32 nds32*-*-elf
2139 *** Changes in GDB 7.11
2141 * GDB now supports debugging kernel-based threads on FreeBSD.
2143 * Per-inferior thread numbers
2145 Thread numbers are now per inferior instead of global. If you're
2146 debugging multiple inferiors, GDB displays thread IDs using a
2147 qualified INF_NUM.THR_NUM form. For example:
2151 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2152 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2153 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2154 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2156 As consequence, thread numbers as visible in the $_thread
2157 convenience variable and in Python's InferiorThread.num attribute
2158 are no longer unique between inferiors.
2160 GDB now maintains a second thread ID per thread, referred to as the
2161 global thread ID, which is the new equivalent of thread numbers in
2162 previous releases. See also $_gthread below.
2164 For backwards compatibility, MI's thread IDs always refer to global
2167 * Commands that accept thread IDs now accept the qualified
2168 INF_NUM.THR_NUM form as well. For example:
2171 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2174 * In commands that accept a list of thread IDs, you can now refer to
2175 all threads of an inferior using a star wildcard. GDB accepts
2176 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2177 refer to all threads of the current inferior. For example, "info
2180 * You can use "info threads -gid" to display the global thread ID of
2183 * The new convenience variable $_gthread holds the global number of
2186 * The new convenience variable $_inferior holds the number of the
2189 * GDB now displays the ID and name of the thread that hit a breakpoint
2190 or received a signal, if your program is multi-threaded. For
2193 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2194 Thread 1 "main" received signal SIGINT, Interrupt.
2196 * Record btrace now supports non-stop mode.
2198 * Support for tracepoints on aarch64-linux was added in GDBserver.
2200 * The 'record instruction-history' command now indicates speculative execution
2201 when using the Intel Processor Trace recording format.
2203 * GDB now allows users to specify explicit locations, bypassing
2204 the linespec parser. This feature is also available to GDB/MI
2207 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2208 GDB now is able to debug both AArch64 applications and ARM applications
2211 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2212 including JIT compiling fast tracepoint's conditional expression bytecode
2215 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2217 * "info threads", "info inferiors", "info display", "info checkpoints"
2218 and "maint info program-spaces" now list the corresponding items in
2219 ascending ID order, for consistency with all other "info" commands.
2221 * In Ada, the overloads selection menu has been enhanced to display the
2222 parameter types and the return types for the matching overloaded subprograms.
2226 maint set target-non-stop (on|off|auto)
2227 maint show target-non-stop
2228 Control whether GDB targets always operate in non-stop mode even if
2229 "set non-stop" is "off". The default is "auto", meaning non-stop
2230 mode is enabled if supported by the target.
2232 maint set bfd-sharing
2233 maint show bfd-sharing
2234 Control the reuse of bfd objects.
2237 show debug bfd-cache
2238 Control display of debugging info regarding bfd caching.
2242 Control display of debugging info regarding FreeBSD threads.
2244 set remote multiprocess-extensions-packet
2245 show remote multiprocess-extensions-packet
2246 Set/show the use of the remote protocol multiprocess extensions.
2248 set remote thread-events
2249 show remote thread-events
2250 Set/show the use of thread create/exit events.
2252 set ada print-signatures on|off
2253 show ada print-signatures"
2254 Control whether parameter types and return types are displayed in overloads
2255 selection menus. It is activated (@code{on}) by default.
2259 Controls the maximum size of memory, in bytes, that GDB will
2260 allocate for value contents. Prevents incorrect programs from
2261 causing GDB to allocate overly large buffers. Default is 64k.
2263 * The "disassemble" command accepts a new modifier: /s.
2264 It prints mixed source+disassembly like /m with two differences:
2265 - disassembled instructions are now printed in program order, and
2266 - and source for all relevant files is now printed.
2267 The "/m" option is now considered deprecated: its "source-centric"
2268 output hasn't proved useful in practice.
2270 * The "record instruction-history" command accepts a new modifier: /s.
2271 It behaves exactly like /m and prints mixed source+disassembly.
2273 * The "set scheduler-locking" command supports a new mode "replay".
2274 It behaves like "off" in record mode and like "on" in replay mode.
2276 * Support for various ROM monitors has been removed:
2278 target dbug dBUG ROM monitor for Motorola ColdFire
2279 target picobug Motorola picobug monitor
2280 target dink32 DINK32 ROM monitor for PowerPC
2281 target m32r Renesas M32R/D ROM monitor
2282 target mon2000 mon2000 ROM monitor
2283 target ppcbug PPCBUG ROM monitor for PowerPC
2285 * Support for reading/writing memory and extracting values on architectures
2286 whose memory is addressable in units of any integral multiple of 8 bits.
2289 Allows to break when an Ada exception is handled.
2291 * New remote packets
2294 Indicates that an exec system call was executed.
2296 exec-events feature in qSupported
2297 The qSupported packet allows GDB to request support for exec
2298 events using the new 'gdbfeature' exec-event, and the qSupported
2299 response can contain the corresponding 'stubfeature'. Set and
2300 show commands can be used to display whether these features are enabled.
2303 Equivalent to interrupting with the ^C character, but works in
2306 thread created stop reason (T05 create:...)
2307 Indicates that the thread was just created and is stopped at entry.
2309 thread exit stop reply (w exitcode;tid)
2310 Indicates that the thread has terminated.
2313 Enables/disables thread create and exit event reporting. For
2314 example, this is used in non-stop mode when GDB stops a set of
2315 threads and synchronously waits for the their corresponding stop
2316 replies. Without exit events, if one of the threads exits, GDB
2317 would hang forever not knowing that it should no longer expect a
2318 stop for that same thread.
2321 Indicates that there are no resumed threads left in the target (all
2322 threads are stopped). The remote stub reports support for this stop
2323 reply to GDB's qSupported query.
2326 Enables/disables catching syscalls from the inferior process.
2327 The remote stub reports support for this packet to GDB's qSupported query.
2329 syscall_entry stop reason
2330 Indicates that a syscall was just called.
2332 syscall_return stop reason
2333 Indicates that a syscall just returned.
2335 * Extended-remote exec events
2337 ** GDB now has support for exec events on extended-remote Linux targets.
2338 For such targets with Linux kernels 2.5.46 and later, this enables
2339 follow-exec-mode and exec catchpoints.
2341 set remote exec-event-feature-packet
2342 show remote exec-event-feature-packet
2343 Set/show the use of the remote exec event feature.
2345 * Thread names in remote protocol
2347 The reply to qXfer:threads:read may now include a name attribute for each
2350 * Target remote mode fork and exec events
2352 ** GDB now has support for fork and exec events on target remote mode
2353 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2354 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2355 fork and exec catchpoints.
2357 * Remote syscall events
2359 ** GDB now has support for catch syscall on remote Linux targets,
2360 currently enabled on x86/x86_64 architectures.
2362 set remote catch-syscall-packet
2363 show remote catch-syscall-packet
2364 Set/show the use of the remote catch syscall feature.
2368 ** The -var-set-format command now accepts the zero-hexadecimal
2369 format. It outputs data in hexadecimal format with zero-padding on the
2374 ** gdb.InferiorThread objects have a new attribute "global_num",
2375 which refers to the thread's global thread ID. The existing
2376 "num" attribute now refers to the thread's per-inferior number.
2377 See "Per-inferior thread numbers" above.
2378 ** gdb.InferiorThread objects have a new attribute "inferior", which
2379 is the Inferior object the thread belongs to.
2381 *** Changes in GDB 7.10
2383 * Support for process record-replay and reverse debugging on aarch64*-linux*
2384 targets has been added. GDB now supports recording of A64 instruction set
2385 including advance SIMD instructions.
2387 * Support for Sun's version of the "stabs" debug file format has been removed.
2389 * GDB now honors the content of the file /proc/PID/coredump_filter
2390 (PID is the process ID) on GNU/Linux systems. This file can be used
2391 to specify the types of memory mappings that will be included in a
2392 corefile. For more information, please refer to the manual page of
2393 "core(5)". GDB also has a new command: "set use-coredump-filter
2394 on|off". It allows to set whether GDB will read the content of the
2395 /proc/PID/coredump_filter file when generating a corefile.
2397 * The "info os" command on GNU/Linux can now display information on
2399 "info os cpus" Listing of all cpus/cores on the system
2401 * GDB has two new commands: "set serial parity odd|even|none" and
2402 "show serial parity". These allows to set or show parity for the
2405 * The "info source" command now displays the producer string if it was
2406 present in the debug info. This typically includes the compiler version
2407 and may include things like its command line arguments.
2409 * The "info dll", an alias of the "info sharedlibrary" command,
2410 is now available on all platforms.
2412 * Directory names supplied to the "set sysroot" commands may be
2413 prefixed with "target:" to tell GDB to access shared libraries from
2414 the target system, be it local or remote. This replaces the prefix
2415 "remote:". The default sysroot has been changed from "" to
2416 "target:". "remote:" is automatically converted to "target:" for
2417 backward compatibility.
2419 * The system root specified by "set sysroot" will be prepended to the
2420 filename of the main executable (if reported to GDB as absolute by
2421 the operating system) when starting processes remotely, and when
2422 attaching to already-running local or remote processes.
2424 * GDB now supports automatic location and retrieval of executable
2425 files from remote targets. Remote debugging can now be initiated
2426 using only a "target remote" or "target extended-remote" command
2427 (no "set sysroot" or "file" commands are required). See "New remote
2430 * The "dump" command now supports verilog hex format.
2432 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2434 * On GNU/Linux, GDB and gdbserver are now able to access executable
2435 and shared library files without a "set sysroot" command when
2436 attaching to processes running in different mount namespaces from
2437 the debugger. This makes it possible to attach to processes in
2438 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2439 See "New remote packets" below.
2441 * The "tui reg" command now provides completion for all of the
2442 available register groups, including target specific groups.
2444 * The HISTSIZE environment variable is no longer read when determining
2445 the size of GDB's command history. GDB now instead reads the dedicated
2446 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2447 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2452 ** Memory ports can now be unbuffered.
2456 ** gdb.Objfile objects have a new attribute "username",
2457 which is the name of the objfile as specified by the user,
2458 without, for example, resolving symlinks.
2459 ** You can now write frame unwinders in Python.
2460 ** gdb.Type objects have a new method "optimized_out",
2461 returning optimized out gdb.Value instance of this type.
2462 ** gdb.Value objects have new methods "reference_value" and
2463 "const_value" which return a reference to the value and a
2464 "const" version of the value respectively.
2468 maint print symbol-cache
2469 Print the contents of the symbol cache.
2471 maint print symbol-cache-statistics
2472 Print statistics of symbol cache usage.
2474 maint flush-symbol-cache
2475 Flush the contents of the symbol cache.
2479 Start branch trace recording using Branch Trace Store (BTS) format.
2482 Evaluate expression by using the compiler and print result.
2486 Explicit commands for enabling and disabling tui mode.
2489 set mpx bound on i386 and amd64
2490 Support for bound table investigation on Intel MPX enabled applications.
2494 Start branch trace recording using Intel Processor Trace format.
2497 Print information about branch tracing internals.
2499 maint btrace packet-history
2500 Print the raw branch tracing data.
2502 maint btrace clear-packet-history
2503 Discard the stored raw branch tracing data.
2506 Discard all branch tracing data. It will be fetched and processed
2507 anew by the next "record" command.
2512 Renamed from "set debug dwarf2-die".
2513 show debug dwarf-die
2514 Renamed from "show debug dwarf2-die".
2516 set debug dwarf-read
2517 Renamed from "set debug dwarf2-read".
2518 show debug dwarf-read
2519 Renamed from "show debug dwarf2-read".
2521 maint set dwarf always-disassemble
2522 Renamed from "maint set dwarf2 always-disassemble".
2523 maint show dwarf always-disassemble
2524 Renamed from "maint show dwarf2 always-disassemble".
2526 maint set dwarf max-cache-age
2527 Renamed from "maint set dwarf2 max-cache-age".
2528 maint show dwarf max-cache-age
2529 Renamed from "maint show dwarf2 max-cache-age".
2531 set debug dwarf-line
2532 show debug dwarf-line
2533 Control display of debugging info regarding DWARF line processing.
2536 show max-completions
2537 Set the maximum number of candidates to be considered during
2538 completion. The default value is 200. This limit allows GDB
2539 to avoid generating large completion lists, the computation of
2540 which can cause the debugger to become temporarily unresponsive.
2542 set history remove-duplicates
2543 show history remove-duplicates
2544 Control the removal of duplicate history entries.
2546 maint set symbol-cache-size
2547 maint show symbol-cache-size
2548 Control the size of the symbol cache.
2550 set|show record btrace bts buffer-size
2551 Set and show the size of the ring buffer used for branch tracing in
2553 The obtained size may differ from the requested size. Use "info
2554 record" to see the obtained buffer size.
2556 set debug linux-namespaces
2557 show debug linux-namespaces
2558 Control display of debugging info regarding Linux namespaces.
2560 set|show record btrace pt buffer-size
2561 Set and show the size of the ring buffer used for branch tracing in
2562 Intel Processor Trace format.
2563 The obtained size may differ from the requested size. Use "info
2564 record" to see the obtained buffer size.
2566 maint set|show btrace pt skip-pad
2567 Set and show whether PAD packets are skipped when computing the
2570 * The command 'thread apply all' can now support new option '-ascending'
2571 to call its specified command for all threads in ascending order.
2573 * Python/Guile scripting
2575 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2576 special section named `.debug_gdb_scripts'.
2578 * New remote packets
2580 qXfer:btrace-conf:read
2581 Return the branch trace configuration for the current thread.
2583 Qbtrace-conf:bts:size
2584 Set the requested ring buffer size for branch tracing in BTS format.
2587 Enable Intel Processor Trace-based branch tracing for the current
2588 process. The remote stub reports support for this packet to GDB's
2591 Qbtrace-conf:pt:size
2592 Set the requested ring buffer size for branch tracing in Intel Processor
2596 Indicates a memory breakpoint instruction was executed, irrespective
2597 of whether it was GDB that planted the breakpoint or the breakpoint
2598 is hardcoded in the program. This is required for correct non-stop
2602 Indicates the target stopped for a hardware breakpoint. This is
2603 required for correct non-stop mode operation.
2606 Return information about files on the remote system.
2608 qXfer:exec-file:read
2609 Return the full absolute name of the file that was executed to
2610 create a process running on the remote system.
2613 Select the filesystem on which vFile: operations with filename
2614 arguments will operate. This is required for GDB to be able to
2615 access files on remote targets where the remote stub does not
2616 share a common filesystem with the inferior(s).
2619 Indicates that a fork system call was executed.
2622 Indicates that a vfork system call was executed.
2624 vforkdone stop reason
2625 Indicates that a vfork child of the specified process has executed
2626 an exec or exit, allowing the vfork parent to resume execution.
2628 fork-events and vfork-events features in qSupported
2629 The qSupported packet allows GDB to request support for fork and
2630 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2631 and the qSupported response can contain the corresponding
2632 'stubfeatures'. Set and show commands can be used to display
2633 whether these features are enabled.
2635 * Extended-remote fork events
2637 ** GDB now has support for fork events on extended-remote Linux
2638 targets. For targets with Linux kernels 2.5.60 and later, this
2639 enables follow-fork-mode and detach-on-fork for both fork and
2640 vfork, as well as fork and vfork catchpoints.
2642 * The info record command now shows the recording format and the
2643 branch tracing configuration for the current thread when using
2644 the btrace record target.
2645 For the BTS format, it shows the ring buffer size.
2647 * GDB now has support for DTrace USDT (Userland Static Defined
2648 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2650 * GDB now supports access to vector registers on S/390 GNU/Linux
2653 * Removed command line options
2655 -xdb HP-UX XDB compatibility mode.
2657 * Removed targets and native configurations
2659 HP/PA running HP-UX hppa*-*-hpux*
2660 Itanium running HP-UX ia64-*-hpux*
2662 * New configure options
2665 This configure option allows the user to build GDB with support for
2666 Intel Processor Trace (default: auto). This requires libipt.
2668 --with-libipt-prefix=PATH
2669 Specify the path to the version of libipt that GDB should use.
2670 $PATH/include should contain the intel-pt.h header and
2671 $PATH/lib should contain the libipt.so library.
2673 *** Changes in GDB 7.9.1
2677 ** Xmethods can now specify a result type.
2679 *** Changes in GDB 7.9
2681 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2685 ** You can now access frame registers from Python scripts.
2686 ** New attribute 'producer' for gdb.Symtab objects.
2687 ** gdb.Objfile objects have a new attribute "progspace",
2688 which is the gdb.Progspace object of the containing program space.
2689 ** gdb.Objfile objects have a new attribute "owner".
2690 ** gdb.Objfile objects have a new attribute "build_id",
2691 which is the build ID generated when the file was built.
2692 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2693 ** A new event "gdb.clear_objfiles" has been added, triggered when
2694 selecting a new file to debug.
2695 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2696 ** New function gdb.lookup_objfile.
2698 New events which are triggered when GDB modifies the state of the
2701 ** gdb.events.inferior_call_pre: Function call is about to be made.
2702 ** gdb.events.inferior_call_post: Function call has just been made.
2703 ** gdb.events.memory_changed: A memory location has been altered.
2704 ** gdb.events.register_changed: A register has been altered.
2706 * New Python-based convenience functions:
2708 ** $_caller_is(name [, number_of_frames])
2709 ** $_caller_matches(regexp [, number_of_frames])
2710 ** $_any_caller_is(name [, number_of_frames])
2711 ** $_any_caller_matches(regexp [, number_of_frames])
2713 * GDB now supports the compilation and injection of source code into
2714 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2715 to compile the source code to object code, and if successful, inject
2716 and execute that code within the current context of the inferior.
2717 Currently the C language is supported. The commands used to
2718 interface with this new feature are:
2720 compile code [-raw|-r] [--] [source code]
2721 compile file [-raw|-r] filename
2725 demangle [-l language] [--] name
2726 Demangle "name" in the specified language, or the current language
2727 if elided. This command is renamed from the "maint demangle" command.
2728 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2729 as "maint demangler-warning".
2731 queue-signal signal-name-or-number
2732 Queue a signal to be delivered to the thread when it is resumed.
2734 add-auto-load-scripts-directory directory
2735 Add entries to the list of directories from which to load auto-loaded
2738 maint print user-registers
2739 List all currently available "user" registers.
2741 compile code [-r|-raw] [--] [source code]
2742 Compile, inject, and execute in the inferior the executable object
2743 code produced by compiling the provided source code.
2745 compile file [-r|-raw] filename
2746 Compile and inject into the inferior the executable object code
2747 produced by compiling the source code stored in the filename
2750 * On resume, GDB now always passes the signal the program had stopped
2751 for to the thread the signal was sent to, even if the user changed
2752 threads before resuming. Previously GDB would often (but not
2753 always) deliver the signal to the thread that happens to be current
2756 * Conversely, the "signal" command now consistently delivers the
2757 requested signal to the current thread. GDB now asks for
2758 confirmation if the program had stopped for a signal and the user
2759 switched threads meanwhile.
2761 * "breakpoint always-inserted" modes "off" and "auto" merged.
2763 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2764 won't remove breakpoints from the target until all threads stop,
2765 even in non-stop mode. The "auto" mode has been removed, and "off"
2766 is now the default mode.
2770 set debug symbol-lookup
2771 show debug symbol-lookup
2772 Control display of debugging info regarding symbol lookup.
2776 ** The -list-thread-groups command outputs an exit-code field for
2777 inferiors that have exited.
2781 MIPS SDE mips*-sde*-elf*
2785 Support for these obsolete configurations has been removed.
2787 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2788 SGI Irix-5.x mips-*-irix5*
2789 SGI Irix-6.x mips-*-irix6*
2790 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2791 VAX running Ultrix vax-*-ultrix*
2793 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2794 and "assf"), have been removed. Use the "sharedlibrary" command, or
2795 its alias "share", instead.
2797 *** Changes in GDB 7.8
2799 * New command line options
2802 This is an alias for the --data-directory option.
2804 * GDB supports printing and modifying of variable length automatic arrays
2805 as specified in ISO C99.
2807 * The ARM simulator now supports instruction level tracing
2808 with or without disassembly.
2812 GDB now has support for scripting using Guile. Whether this is
2813 available is determined at configure time.
2814 Guile version 2.0 or greater is required.
2815 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2817 * New commands (for set/show, see "New options" below)
2821 Invoke CODE by passing it to the Guile interpreter.
2825 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2827 info auto-load guile-scripts [regexp]
2828 Print the list of automatically loaded Guile scripts.
2830 * The source command is now capable of sourcing Guile scripts.
2831 This feature is dependent on the debugger being built with Guile support.
2835 set print symbol-loading (off|brief|full)
2836 show print symbol-loading
2837 Control whether to print informational messages when loading symbol
2838 information for a file. The default is "full", but when debugging
2839 programs with large numbers of shared libraries the amount of output
2840 becomes less useful.
2842 set guile print-stack (none|message|full)
2843 show guile print-stack
2844 Show a stack trace when an error is encountered in a Guile script.
2846 set auto-load guile-scripts (on|off)
2847 show auto-load guile-scripts
2848 Control auto-loading of Guile script files.
2850 maint ada set ignore-descriptive-types (on|off)
2851 maint ada show ignore-descriptive-types
2852 Control whether the debugger should ignore descriptive types in Ada
2853 programs. The default is not to ignore the descriptive types. See
2854 the user manual for more details on descriptive types and the intended
2855 usage of this option.
2857 set auto-connect-native-target
2859 Control whether GDB is allowed to automatically connect to the
2860 native target for the run, attach, etc. commands when not connected
2861 to any target yet. See also "target native" below.
2863 set record btrace replay-memory-access (read-only|read-write)
2864 show record btrace replay-memory-access
2865 Control what memory accesses are allowed during replay.
2867 maint set target-async (on|off)
2868 maint show target-async
2869 This controls whether GDB targets operate in synchronous or
2870 asynchronous mode. Normally the default is asynchronous, if it is
2871 available; but this can be changed to more easily debug problems
2872 occurring only in synchronous mode.
2874 set mi-async (on|off)
2876 Control whether MI asynchronous mode is preferred. This supersedes
2877 "set target-async" of previous GDB versions.
2879 * "set target-async" is deprecated as a CLI option and is now an alias
2880 for "set mi-async" (only puts MI into async mode).
2882 * Background execution commands (e.g., "c&", "s&", etc.) are now
2883 possible ``out of the box'' if the target supports them. Previously
2884 the user would need to explicitly enable the possibility with the
2885 "set target-async on" command.
2887 * New features in the GDB remote stub, GDBserver
2889 ** New option --debug-format=option1[,option2,...] allows one to add
2890 additional text to each output. At present only timestamps
2891 are supported: --debug-format=timestamps.
2892 Timestamps can also be turned on with the
2893 "monitor set debug-format timestamps" command from GDB.
2895 * The 'record instruction-history' command now starts counting instructions
2896 at one. This also affects the instruction ranges reported by the
2897 'record function-call-history' command when given the /i modifier.
2899 * The command 'record function-call-history' supports a new modifier '/c' to
2900 indent the function names based on their call stack depth.
2901 The fields for the '/i' and '/l' modifier have been reordered.
2902 The source line range is now prefixed with 'at'.
2903 The instruction range is now prefixed with 'inst'.
2904 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2905 "record instruction-history" and "list" commands.
2907 * The ranges given as arguments to the 'record function-call-history' and
2908 'record instruction-history' commands are now inclusive.
2910 * The btrace record target now supports the 'record goto' command.
2911 For locations inside the execution trace, the back trace is computed
2912 based on the information stored in the execution trace.
2914 * The btrace record target supports limited reverse execution and replay.
2915 The target does not record data and therefore does not allow reading
2916 memory or registers.
2918 * The "catch syscall" command now works on s390*-linux* targets.
2920 * The "compare-sections" command is no longer specific to target
2921 remote. It now works with all targets.
2923 * All native targets are now consistently called "native".
2924 Consequently, the "target child", "target GNU", "target djgpp",
2925 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2926 commands have been replaced with "target native". The QNX/NTO port
2927 leaves the "procfs" target in place and adds a "native" target for
2928 consistency with other ports. The impact on users should be minimal
2929 as these commands previously either throwed an error, or were
2930 no-ops. The target's name is visible in the output of the following
2931 commands: "help target", "info target", "info files", "maint print
2934 * The "target native" command now connects to the native target. This
2935 can be used to launch native programs even when "set
2936 auto-connect-native-target" is set to off.
2938 * GDB now supports access to Intel MPX registers on GNU/Linux.
2940 * Support for Intel AVX-512 registers on GNU/Linux.
2941 Support displaying and modifying Intel AVX-512 registers
2942 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2944 * New remote packets
2946 qXfer:btrace:read's annex
2947 The qXfer:btrace:read packet supports a new annex 'delta' to read
2948 branch trace incrementally.
2952 ** Valid Python operations on gdb.Value objects representing
2953 structs/classes invoke the corresponding overloaded operators if
2955 ** New `Xmethods' feature in the Python API. Xmethods are
2956 additional methods or replacements for existing methods of a C++
2957 class. This feature is useful for those cases where a method
2958 defined in C++ source code could be inlined or optimized out by
2959 the compiler, making it unavailable to GDB.
2962 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2964 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2965 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2966 its alias "share", instead.
2968 * The commands "set remotebaud" and "show remotebaud" are no longer
2969 supported. Use "set serial baud" and "show serial baud" (respectively)
2974 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2975 target-async". The latter is left as a deprecated alias of the
2976 former for backward compatibility. If the target supports it,
2977 CLI background execution commands are now always possible by
2978 default, independently of whether the frontend stated a
2979 preference for asynchronous execution with "-gdb-set mi-async".
2980 Previously "-gdb-set target-async off" affected both MI execution
2981 commands and CLI execution commands.
2983 *** Changes in GDB 7.7
2985 * Improved support for process record-replay and reverse debugging on
2986 arm*-linux* targets. Support for thumb32 and syscall instruction
2987 recording has been added.
2989 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2991 * GDB now supports Fission DWP file format version 2.
2992 http://gcc.gnu.org/wiki/DebugFission
2994 * New convenience function "$_isvoid", to check whether an expression
2995 is void. A void expression is an expression where the type of the
2996 result is "void". For example, some convenience variables may be
2997 "void" when evaluated (e.g., "$_exitcode" before the execution of
2998 the program being debugged; or an undefined convenience variable).
2999 Another example, when calling a function whose return type is
3002 * The "maintenance print objfiles" command now takes an optional regexp.
3004 * The "catch syscall" command now works on arm*-linux* targets.
3006 * GDB now consistently shows "<not saved>" when printing values of
3007 registers the debug info indicates have not been saved in the frame
3008 and there's nowhere to retrieve them from
3009 (callee-saved/call-clobbered registers):
3014 (gdb) info registers rax
3017 Before, the former would print "<optimized out>", and the latter
3018 "*value not available*".
3020 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3025 ** Frame filters and frame decorators have been added.
3026 ** Temporary breakpoints are now supported.
3027 ** Line tables representation has been added.
3028 ** New attribute 'parent_type' for gdb.Field objects.
3029 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3030 ** New attribute 'name' for gdb.Type objects.
3034 Nios II ELF nios2*-*-elf
3035 Nios II GNU/Linux nios2*-*-linux
3036 Texas Instruments MSP430 msp430*-*-elf
3038 * Removed native configurations
3040 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3041 been removed. ELF variants of these configurations are kept supported.
3043 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3044 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3045 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3046 i[34567]86-*-openbsd3.[0-3]
3047 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3048 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3049 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3053 Like "catch throw", but catches a re-thrown exception.
3054 maint check-psymtabs
3055 Renamed from old "maint check-symtabs".
3057 Perform consistency checks on symtabs.
3058 maint expand-symtabs
3059 Expand symtabs matching an optional regexp.
3062 Display the details of GDB configure-time options.
3064 maint set|show per-command
3065 maint set|show per-command space
3066 maint set|show per-command time
3067 maint set|show per-command symtab
3068 Enable display of per-command gdb resource usage.
3070 remove-symbol-file FILENAME
3071 remove-symbol-file -a ADDRESS
3072 Remove a symbol file added via add-symbol-file. The file to remove
3073 can be identified by its filename or by an address that lies within
3074 the boundaries of this symbol file in memory.
3077 info exceptions REGEXP
3078 Display the list of Ada exceptions defined in the program being
3079 debugged. If provided, only the exceptions whose names match REGEXP
3084 set debug symfile off|on
3086 Control display of debugging info regarding reading symbol files and
3087 symbol tables within those files
3089 set print raw frame-arguments
3090 show print raw frame-arguments
3091 Set/show whether to print frame arguments in raw mode,
3092 disregarding any defined pretty-printers.
3094 set remote trace-status-packet
3095 show remote trace-status-packet
3096 Set/show the use of remote protocol qTStatus packet.
3100 Control display of debugging messages related to Nios II targets.
3104 Control whether target-assisted range stepping is enabled.
3106 set startup-with-shell
3107 show startup-with-shell
3108 Specifies whether Unix child processes are started via a shell or
3113 Use the target memory cache for accesses to the code segment. This
3114 improves performance of remote debugging (particularly disassembly).
3116 * You can now use a literal value 'unlimited' for options that
3117 interpret 0 or -1 as meaning "unlimited". E.g., "set
3118 trace-buffer-size unlimited" is now an alias for "set
3119 trace-buffer-size -1" and "set height unlimited" is now an alias for
3122 * The "set debug symtab-create" debugging option of GDB has been changed to
3123 accept a verbosity level. 0 means "off", 1 provides basic debugging
3124 output, and values of 2 or greater provides more verbose output.
3126 * New command-line options
3128 Display the details of GDB configure-time options.
3130 * The command 'tsave' can now support new option '-ctf' to save trace
3131 buffer in Common Trace Format.
3133 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3136 * GDB now implements the C++ 'typeid' operator.
3138 * The new convenience variable $_exception holds the exception being
3139 thrown or caught at an exception-related catchpoint.
3141 * The exception-related catchpoints, like "catch throw", now accept a
3142 regular expression which can be used to filter exceptions by type.
3144 * The new convenience variable $_exitsignal is automatically set to
3145 the terminating signal number when the program being debugged dies
3146 due to an uncaught signal.
3150 ** All MI commands now accept an optional "--language" option.
3151 Support for this feature can be verified by using the "-list-features"
3152 command, which should contain "language-option".
3154 ** The new command -info-gdb-mi-command allows the user to determine
3155 whether a GDB/MI command is supported or not.
3157 ** The "^error" result record returned when trying to execute an undefined
3158 GDB/MI command now provides a variable named "code" whose content is the
3159 "undefined-command" error code. Support for this feature can be verified
3160 by using the "-list-features" command, which should contain
3161 "undefined-command-error-code".
3163 ** The -trace-save MI command can optionally save trace buffer in Common
3166 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3168 ** The command -data-list-register-values now accepts an optional
3169 "--skip-unavailable" option. When used, only the available registers
3172 ** The new command -trace-frame-collected dumps collected variables,
3173 computed expressions, tvars, memory and registers in a traceframe.
3175 ** The commands -stack-list-locals, -stack-list-arguments and
3176 -stack-list-variables now accept an option "--skip-unavailable".
3177 When used, only the available locals or arguments are displayed.
3179 ** The -exec-run command now accepts an optional "--start" option.
3180 When used, the command follows the same semantics as the "start"
3181 command, stopping the program's execution at the start of its
3182 main subprogram. Support for this feature can be verified using
3183 the "-list-features" command, which should contain
3184 "exec-run-start-option".
3186 ** The new commands -catch-assert and -catch-exceptions insert
3187 catchpoints stopping the program when Ada exceptions are raised.
3189 ** The new command -info-ada-exceptions provides the equivalent of
3190 the new "info exceptions" command.
3192 * New system-wide configuration scripts
3193 A GDB installation now provides scripts suitable for use as system-wide
3194 configuration scripts for the following systems:
3198 * GDB now supports target-assigned range stepping with remote targets.
3199 This improves the performance of stepping source lines by reducing
3200 the number of control packets from/to GDB. See "New remote packets"
3203 * GDB now understands the element 'tvar' in the XML traceframe info.
3204 It has the id of the collected trace state variables.
3206 * On S/390 targets that provide the transactional-execution feature,
3207 the program interruption transaction diagnostic block (TDB) is now
3208 represented as a number of additional "registers" in GDB.
3210 * New remote packets
3214 The vCont packet supports a new 'r' action, that tells the remote
3215 stub to step through an address range itself, without GDB
3216 involvemement at each single-step.
3218 qXfer:libraries-svr4:read's annex
3219 The previously unused annex of the qXfer:libraries-svr4:read packet
3220 is now used to support passing an argument list. The remote stub
3221 reports support for this argument list to GDB's qSupported query.
3222 The defined arguments are "start" and "prev", used to reduce work
3223 necessary for library list updating, resulting in significant
3226 * New features in the GDB remote stub, GDBserver
3228 ** GDBserver now supports target-assisted range stepping. Currently
3229 enabled on x86/x86_64 GNU/Linux targets.
3231 ** GDBserver now adds element 'tvar' in the XML in the reply to
3232 'qXfer:traceframe-info:read'. It has the id of the collected
3233 trace state variables.
3235 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3238 * New 'z' formatter for printing and examining memory, this displays the
3239 value as hexadecimal zero padded on the left to the size of the type.
3241 * GDB can now use Windows x64 unwinding data.
3243 * The "set remotebaud" command has been replaced by "set serial baud".
3244 Similarly, "show remotebaud" has been replaced by "show serial baud".
3245 The "set remotebaud" and "show remotebaud" commands are still available
3246 to provide backward compatibility with older versions of GDB.
3248 *** Changes in GDB 7.6
3250 * Target record has been renamed to record-full.
3251 Record/replay is now enabled with the "record full" command.
3252 This also affects settings that are associated with full record/replay
3253 that have been moved from "set/show record" to "set/show record full":
3255 set|show record full insn-number-max
3256 set|show record full stop-at-limit
3257 set|show record full memory-query
3259 * A new record target "record-btrace" has been added. The new target
3260 uses hardware support to record the control-flow of a process. It
3261 does not support replaying the execution, but it implements the
3262 below new commands for investigating the recorded execution log.
3263 This new recording method can be enabled using:
3267 The "record-btrace" target is only available on Intel Atom processors
3268 and requires a Linux kernel 2.6.32 or later.
3270 * Two new commands have been added for record/replay to give information
3271 about the recorded execution without having to replay the execution.
3272 The commands are only supported by "record btrace".
3274 record instruction-history prints the execution history at
3275 instruction granularity
3277 record function-call-history prints the execution history at
3278 function granularity
3280 * New native configurations
3282 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3283 FreeBSD/powerpc powerpc*-*-freebsd
3284 x86_64/Cygwin x86_64-*-cygwin*
3285 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3289 ARM AArch64 aarch64*-*-elf
3290 ARM AArch64 GNU/Linux aarch64*-*-linux
3291 Lynx 178 PowerPC powerpc-*-lynx*178
3292 x86_64/Cygwin x86_64-*-cygwin*
3293 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3295 * If the configured location of system.gdbinit file (as given by the
3296 --with-system-gdbinit option at configure time) is in the
3297 data-directory (as specified by --with-gdb-datadir at configure
3298 time) or in one of its subdirectories, then GDB will look for the
3299 system-wide init file in the directory specified by the
3300 --data-directory command-line option.
3302 * New command line options:
3304 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3305 other initialization files, unlike -nx which disables all of them.
3307 * Removed command line options
3309 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3312 * The 'ptype' and 'whatis' commands now accept an argument to control
3315 * 'info proc' now works on some core files.
3319 ** Vectors can be created with gdb.Type.vector.
3321 ** Python's atexit.register now works in GDB.
3323 ** Types can be pretty-printed via a Python API.
3325 ** Python 3 is now supported (in addition to Python 2.4 or later)
3327 ** New class gdb.Architecture exposes GDB's internal representation
3328 of architecture in the Python API.
3330 ** New method Frame.architecture returns the gdb.Architecture object
3331 corresponding to the frame's architecture.
3333 * New Python-based convenience functions:
3335 ** $_memeq(buf1, buf2, length)
3336 ** $_streq(str1, str2)
3338 ** $_regex(str, regex)
3340 * The 'cd' command now defaults to using '~' (the home directory) if not
3343 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3344 default for GCC since November 2000.
3346 * The command 'forward-search' can now be abbreviated as 'fo'.
3348 * The command 'info tracepoints' can now display 'installed on target'
3349 or 'not installed on target' for each non-pending location of tracepoint.
3351 * New configure options
3353 --enable-libmcheck/--disable-libmcheck
3354 By default, development versions are built with -lmcheck on hosts
3355 that support it, in order to help track memory corruption issues.
3356 Release versions, on the other hand, are built without -lmcheck
3357 by default. The --enable-libmcheck/--disable-libmcheck configure
3358 options allow the user to override that default.
3359 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3360 This configure option allows the user to build GDB with
3361 libbabeltrace using which GDB can read Common Trace Format data.
3363 * New commands (for set/show, see "New options" below)
3366 Catch signals. This is similar to "handle", but allows commands and
3367 conditions to be attached.
3370 List the BFDs known to GDB.
3372 python-interactive [command]
3374 Start a Python interactive prompt, or evaluate the optional command
3375 and print the result of expressions.
3378 "py" is a new alias for "python".
3380 enable type-printer [name]...
3381 disable type-printer [name]...
3382 Enable or disable type printers.
3386 ** For the Renesas Super-H architecture, the "regs" command has been removed
3387 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3392 set print type methods (on|off)
3393 show print type methods
3394 Control whether method declarations are displayed by "ptype".
3395 The default is to show them.
3397 set print type typedefs (on|off)
3398 show print type typedefs
3399 Control whether typedef definitions are displayed by "ptype".
3400 The default is to show them.
3402 set filename-display basename|relative|absolute
3403 show filename-display
3404 Control the way in which filenames is displayed.
3405 The default is "relative", which preserves previous behavior.
3407 set trace-buffer-size
3408 show trace-buffer-size
3409 Request target to change the size of trace buffer.
3411 set remote trace-buffer-size-packet auto|on|off
3412 show remote trace-buffer-size-packet
3413 Control the use of the remote protocol `QTBuffer:size' packet.
3417 Control display of debugging messages related to ARM AArch64.
3420 set debug coff-pe-read
3421 show debug coff-pe-read
3422 Control display of debugging messages related to reading of COFF/PE
3427 Control display of debugging messages related to Mach-O symbols
3430 set debug notification
3431 show debug notification
3432 Control display of debugging info for async remote notification.
3436 ** Command parameter changes are now notified using new async record
3437 "=cmd-param-changed".
3438 ** Trace frame changes caused by command "tfind" are now notified using
3439 new async record "=traceframe-changed".
3440 ** The creation, deletion and modification of trace state variables
3441 are now notified using new async records "=tsv-created",
3442 "=tsv-deleted" and "=tsv-modified".
3443 ** The start and stop of process record are now notified using new
3444 async record "=record-started" and "=record-stopped".
3445 ** Memory changes are now notified using new async record
3447 ** The data-disassemble command response will include a "fullname" field
3448 containing the absolute file name when source has been requested.
3449 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3450 command, to allow pattern filling of memory areas.
3451 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3452 library load/unload events.
3453 ** The response to breakpoint commands and breakpoint async records
3454 includes an "installed" field containing a boolean state about each
3455 non-pending tracepoint location is whether installed on target or not.
3456 ** Output of the "-trace-status" command includes a "trace-file" field
3457 containing the name of the trace file being examined. This field is
3458 optional, and only present when examining a trace file.
3459 ** The "fullname" field is now always present along with the "file" field,
3460 even if the file cannot be found by GDB.
3462 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3463 You must have the LZMA library available when configuring GDB for this
3464 feature to be enabled. For more information, see:
3465 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3467 * New remote packets
3470 Set the size of trace buffer. The remote stub reports support for this
3471 packet to gdb's qSupported query.
3474 Enable Branch Trace Store (BTS)-based branch tracing for the current
3475 thread. The remote stub reports support for this packet to gdb's
3479 Disable branch tracing for the current thread. The remote stub reports
3480 support for this packet to gdb's qSupported query.
3483 Read the traced branches for the current thread. The remote stub
3484 reports support for this packet to gdb's qSupported query.
3486 *** Changes in GDB 7.5
3488 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3489 for more x32 ABI info.
3491 * GDB now supports access to MIPS DSP registers on Linux targets.
3493 * GDB now supports debugging microMIPS binaries.
3495 * The "info os" command on GNU/Linux can now display information on
3496 several new classes of objects managed by the operating system:
3497 "info os procgroups" lists process groups
3498 "info os files" lists file descriptors
3499 "info os sockets" lists internet-domain sockets
3500 "info os shm" lists shared-memory regions
3501 "info os semaphores" lists semaphores
3502 "info os msg" lists message queues
3503 "info os modules" lists loaded kernel modules
3505 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3506 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3507 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3508 options and inspect the probe arguments using the new $_probe_arg family
3509 of convenience variables. You can obtain more information about SystemTap
3510 in <http://sourceware.org/systemtap/>.
3512 * GDB now supports reversible debugging on ARM, it allows you to
3513 debug basic ARM and THUMB instructions, and provides
3514 record/replay support.
3516 * The option "symbol-reloading" has been deleted as it is no longer used.
3520 ** GDB commands implemented in Python can now be put in command class
3523 ** The "maint set python print-stack on|off" is now deleted.
3525 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3526 apply "flag enum"-style pretty-printing to any enum.
3528 ** gdb.lookup_symbol can now work when there is no current frame.
3530 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3531 the source at which the symbol was defined.
3533 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3534 method 'value'. The former indicates whether the symbol needs a
3535 frame in order to compute its value, and the latter computes the
3538 ** A new method 'referenced_value' on gdb.Value objects which can
3539 dereference pointer as well as C++ reference values.
3541 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3542 which return the global and static blocks (as gdb.Block objects),
3543 of the underlying symbol table, respectively.
3545 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3546 object associated with a PC value.
3548 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3549 of the address range occupied by code for the current source line.
3551 * Go language support.
3552 GDB now supports debugging programs written in the Go programming
3555 * GDBserver now supports stdio connections.
3556 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3558 * The binary "gdbtui" can no longer be built or installed.
3559 Use "gdb -tui" instead.
3561 * GDB will now print "flag" enums specially. A flag enum is one where
3562 all the enumerator values have no bits in common when pairwise
3563 "and"ed. When printing a value whose type is a flag enum, GDB will
3564 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3565 (gdb) print (enum E) 3
3568 * The filename part of a linespec will now match trailing components
3569 of a source file name. For example, "break gcc/expr.c:1000" will
3570 now set a breakpoint in build/gcc/expr.c, but not
3571 build/libcpp/expr.c.
3573 * The "info proc" and "generate-core-file" commands will now also
3574 work on remote targets connected to GDBserver on Linux.
3576 * The command "info catch" has been removed. It has been disabled
3577 since December 2007.
3579 * The "catch exception" and "catch assert" commands now accept
3580 a condition at the end of the command, much like the "break"
3581 command does. For instance:
3583 (gdb) catch exception Constraint_Error if Barrier = True
3585 Previously, it was possible to add a condition to such catchpoints,
3586 but it had to be done as a second step, after the catchpoint had been
3587 created, using the "condition" command.
3589 * The "info static-tracepoint-marker" command will now also work on
3590 native Linux targets with in-process agent.
3592 * GDB can now set breakpoints on inlined functions.
3594 * The .gdb_index section has been updated to include symbols for
3595 inlined functions. GDB will ignore older .gdb_index sections by
3596 default, which could cause symbol files to be loaded more slowly
3597 until their .gdb_index sections can be recreated. The new command
3598 "set use-deprecated-index-sections on" will cause GDB to use any older
3599 .gdb_index sections it finds. This will restore performance, but the
3600 ability to set breakpoints on inlined functions will be lost in symbol
3601 files with older .gdb_index sections.
3603 The .gdb_index section has also been updated to record more information
3604 about each symbol. This speeds up the "info variables", "info functions"
3605 and "info types" commands when used with programs having the .gdb_index
3606 section, as well as speeding up debugging with shared libraries using
3607 the .gdb_index section.
3609 * Ada support for GDB/MI Variable Objects has been added.
3611 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3616 ** New command -info-os is the MI equivalent of "info os".
3618 ** Output logs ("set logging" and related) now include MI output.
3622 ** "set use-deprecated-index-sections on|off"
3623 "show use-deprecated-index-sections on|off"
3624 Controls the use of deprecated .gdb_index sections.
3626 ** "catch load" and "catch unload" can be used to stop when a shared
3627 library is loaded or unloaded, respectively.
3629 ** "enable count" can be used to auto-disable a breakpoint after
3632 ** "info vtbl" can be used to show the virtual method tables for
3633 C++ and Java objects.
3635 ** "explore" and its sub commands "explore value" and "explore type"
3636 can be used to recursively explore values and types of
3637 expressions. These commands are available only if GDB is
3638 configured with '--with-python'.
3640 ** "info auto-load" shows status of all kinds of auto-loaded files,
3641 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3642 sequences of commands files, "info auto-load python-scripts"
3643 shows status of auto-loading Python script files,
3644 "info auto-load local-gdbinit" shows status of loading init file
3645 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3646 status of inferior specific thread debugging shared library loading.
3648 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3649 and "show auto-load-scripts" commands have been deprecated, use their
3650 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3651 and "show auto-load python-scripts" counterparts instead.
3653 ** "dprintf location,format,args..." creates a dynamic printf, which
3654 is basically a breakpoint that does a printf and immediately
3655 resumes your program's execution, so it is like a printf that you
3656 can insert dynamically at runtime instead of at compiletime.
3658 ** "set print symbol"
3660 Controls whether GDB attempts to display the symbol, if any,
3661 corresponding to addresses it prints. This defaults to "on", but
3662 you can set it to "off" to restore GDB's previous behavior.
3664 * Deprecated commands
3666 ** For the Renesas Super-H architecture, the "regs" command has been
3667 deprecated, and "info all-registers" should be used instead.
3671 Renesas RL78 rl78-*-elf
3672 HP OpenVMS ia64 ia64-hp-openvms*
3674 * GDBserver supports evaluation of breakpoint conditions. When
3675 support is advertised by GDBserver, GDB may be told to send the
3676 breakpoint conditions in bytecode form to GDBserver. GDBserver
3677 will only report the breakpoint trigger to GDB when its condition
3682 set mips compression
3683 show mips compression
3684 Select the compressed ISA encoding used in functions that have no symbol
3685 information available. The encoding can be set to either of:
3688 and is updated automatically from ELF file flags if available.
3690 set breakpoint condition-evaluation
3691 show breakpoint condition-evaluation
3692 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3693 GDBserver ("target"). Default option "auto" chooses the most efficient
3695 This option can improve debugger efficiency depending on the speed of the
3699 Disable auto-loading globally.
3702 Show auto-loading setting of all kinds of auto-loaded files.
3704 set auto-load gdb-scripts on|off
3705 show auto-load gdb-scripts
3706 Control auto-loading of GDB canned sequences of commands files.
3708 set auto-load python-scripts on|off
3709 show auto-load python-scripts
3710 Control auto-loading of Python script files.
3712 set auto-load local-gdbinit on|off
3713 show auto-load local-gdbinit
3714 Control loading of init file (.gdbinit) from current directory.
3716 set auto-load libthread-db on|off
3717 show auto-load libthread-db
3718 Control auto-loading of inferior specific thread debugging shared library.
3720 set auto-load scripts-directory <dir1>[:<dir2>...]
3721 show auto-load scripts-directory
3722 Set a list of directories from which to load auto-loaded scripts.
3723 Automatically loaded Python scripts and GDB scripts are located in one
3724 of the directories listed by this option.
3725 The delimiter (':' above) may differ according to the host platform.
3727 set auto-load safe-path <dir1>[:<dir2>...]
3728 show auto-load safe-path
3729 Set a list of directories from which it is safe to auto-load files.
3730 The delimiter (':' above) may differ according to the host platform.
3732 set debug auto-load on|off
3733 show debug auto-load
3734 Control display of debugging info for auto-loading the files above.
3736 set dprintf-style gdb|call|agent
3738 Control the way in which a dynamic printf is performed; "gdb"
3739 requests a GDB printf command, while "call" causes dprintf to call a
3740 function in the inferior. "agent" requests that the target agent
3741 (such as GDBserver) do the printing.
3743 set dprintf-function <expr>
3744 show dprintf-function
3745 set dprintf-channel <expr>
3746 show dprintf-channel
3747 Set the function and optional first argument to the call when using
3748 the "call" style of dynamic printf.
3750 set disconnected-dprintf on|off
3751 show disconnected-dprintf
3752 Control whether agent-style dynamic printfs continue to be in effect
3753 after GDB disconnects.
3755 * New configure options
3757 --with-auto-load-dir
3758 Configure default value for the 'set auto-load scripts-directory'
3759 setting above. It defaults to '$debugdir:$datadir/auto-load',
3760 $debugdir representing global debugging info directories (available
3761 via 'show debug-file-directory') and $datadir representing GDB's data
3762 directory (available via 'show data-directory').
3764 --with-auto-load-safe-path
3765 Configure default value for the 'set auto-load safe-path' setting
3766 above. It defaults to the --with-auto-load-dir setting.
3768 --without-auto-load-safe-path
3769 Set 'set auto-load safe-path' to '/', effectively disabling this
3772 * New remote packets
3774 z0/z1 conditional breakpoints extension
3776 The z0/z1 breakpoint insertion packets have been extended to carry
3777 a list of conditional expressions over to the remote stub depending on the
3778 condition evaluation mode. The use of this extension can be controlled
3779 via the "set remote conditional-breakpoints-packet" command.
3783 Specify the signals which the remote stub may pass to the debugged
3784 program without GDB involvement.
3786 * New command line options
3788 --init-command=FILE, -ix Like --command, -x but execute it
3789 before loading inferior.
3790 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3791 execute it before loading inferior.
3793 *** Changes in GDB 7.4
3795 * GDB now handles ambiguous linespecs more consistently; the existing
3796 FILE:LINE support has been expanded to other types of linespecs. A
3797 breakpoint will now be set on all matching locations in all
3798 inferiors, and locations will be added or removed according to
3801 * GDB now allows you to skip uninteresting functions and files when
3802 stepping with the "skip function" and "skip file" commands.
3804 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3805 and "show remote hardware-watchpoint-length-limit". These allows to
3806 set or show the maximum length limit (in bytes) of a remote
3807 target hardware watchpoint.
3809 This allows e.g. to use "unlimited" hardware watchpoints with the
3810 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3811 watchpoints are slower than real hardware watchpoints but are
3812 significantly faster than gdb software watchpoints.
3816 ** The register_pretty_printer function in module gdb.printing now takes
3817 an optional `replace' argument. If True, the new printer replaces any
3820 ** The "maint set python print-stack on|off" command has been
3821 deprecated and will be deleted in GDB 7.5.
3822 A new command: "set python print-stack none|full|message" has
3823 replaced it. Additionally, the default for "print-stack" is
3824 now "message", which just prints the error message without
3827 ** A prompt substitution hook (prompt_hook) is now available to the
3830 ** A new Python module, gdb.prompt has been added to the GDB Python
3831 modules library. This module provides functionality for
3832 escape sequences in prompts (used by set/show
3833 extended-prompt). These escape sequences are replaced by their
3834 corresponding value.
3836 ** Python commands and convenience-functions located in
3837 'data-directory'/python/gdb/command and
3838 'data-directory'/python/gdb/function are now automatically loaded
3841 ** Blocks now provide four new attributes. global_block and
3842 static_block will return the global and static blocks
3843 respectively. is_static and is_global are boolean attributes
3844 that indicate if the block is one of those two types.
3846 ** Symbols now provide the "type" attribute, the type of the symbol.
3848 ** The "gdb.breakpoint" function has been deprecated in favor of
3851 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3852 of a function. This class is based on the "finish" command
3853 available in the CLI.
3855 ** Type objects for struct and union types now allow access to
3856 the fields using standard Python dictionary (mapping) methods.
3857 For example, "some_type['myfield']" now works, as does
3858 "some_type.items()".
3860 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3863 ** A new function, "deep_items" has been added to the gdb.types
3864 module in the GDB Python modules library. This function returns
3865 an iterator over the fields of a struct or union type. Unlike
3866 the standard Python "iteritems" method, it will recursively traverse
3867 any anonymous fields.
3871 ** "*stopped" events can report several new "reason"s, such as
3874 ** Breakpoint changes are now notified using new async records, like
3875 "=breakpoint-modified".
3877 ** New command -ada-task-info.
3879 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3880 $sdir specifies the default system locations of shared libraries.
3881 $pdir specifies the directory where the libpthread used by the application
3884 GDB no longer looks in $sdir and $pdir after it has searched the directories
3885 mentioned in libthread-db-search-path. If you want to search those
3886 directories, they must be specified in libthread-db-search-path.
3887 The default value of libthread-db-search-path on GNU/Linux and Solaris
3888 systems is now "$sdir:$pdir".
3890 $pdir is not supported by gdbserver, it is currently ignored.
3891 $sdir is supported by gdbserver.
3893 * New configure option --with-iconv-bin.
3894 When using the internationalization support like the one in the GNU C
3895 library, GDB will invoke the "iconv" program to get a list of supported
3896 character sets. If this program lives in a non-standard location, one can
3897 use this option to specify where to find it.
3899 * When natively debugging programs on PowerPC BookE processors running
3900 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3901 watchpoints, which specify a mask in addition to an address to watch.
3902 The mask specifies that some bits of an address (the bits which are
3903 reset in the mask) should be ignored when matching the address accessed
3904 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3905 section in the user manual for more details.
3907 * The new option --once causes GDBserver to stop listening for connections once
3908 the first connection is made. The listening port used by GDBserver will
3909 become available after that.
3911 * New commands "info macros" and "alias" have been added.
3913 * New function parameters suffix @entry specifies value of function parameter
3914 at the time the function got called. Entry values are available only since
3920 "!" is now an alias of the "shell" command.
3921 Note that no space is needed between "!" and SHELL COMMAND.
3925 watch EXPRESSION mask MASK_VALUE
3926 The watch command now supports the mask argument which allows creation
3927 of masked watchpoints, if the current architecture supports this feature.
3929 info auto-load-scripts [REGEXP]
3930 This command was formerly named "maintenance print section-scripts".
3931 It is now generally useful and is no longer a maintenance-only command.
3933 info macro [-all] [--] MACRO
3934 The info macro command has new options `-all' and `--'. The first for
3935 printing all definitions of a macro. The second for explicitly specifying
3936 the end of arguments and the beginning of the macro name in case the macro
3937 name starts with a hyphen.
3939 collect[/s] EXPRESSIONS
3940 The tracepoint collect command now takes an optional modifier "/s"
3941 that directs it to dereference pointer-to-character types and
3942 collect the bytes of memory up to a zero byte. The behavior is
3943 similar to what you see when you use the regular print command on a
3944 string. An optional integer following the "/s" sets a bound on the
3945 number of bytes that will be collected.
3948 The trace start command now interprets any supplied arguments as a
3949 note to be recorded with the trace run, with an effect similar to
3950 setting the variable trace-notes.
3953 The trace stop command now interprets any arguments as a note to be
3954 mentioned along with the tstatus report that the trace was stopped
3955 with a command. The effect is similar to setting the variable
3958 * Tracepoints can now be enabled and disabled at any time after a trace
3959 experiment has been started using the standard "enable" and "disable"
3960 commands. It is now possible to start a trace experiment with no enabled
3961 tracepoints; GDB will display a warning, but will allow the experiment to
3962 begin, assuming that tracepoints will be enabled as needed while the trace
3965 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3966 locations with 4-byte instructions, when they were previously
3967 limited to locations with instructions of 5 bytes or longer.
3971 set debug dwarf2-read
3972 show debug dwarf2-read
3973 Turns on or off display of debugging messages related to reading
3974 DWARF debug info. The default is off.
3976 set debug symtab-create
3977 show debug symtab-create
3978 Turns on or off display of debugging messages related to symbol table
3979 creation. The default is off.
3982 show extended-prompt
3983 Set the GDB prompt, and allow escape sequences to be inserted to
3984 display miscellaneous information (see 'help set extended-prompt'
3985 for the list of sequences). This prompt (and any information
3986 accessed through the escape sequences) is updated every time the
3987 prompt is displayed.
3989 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3990 show print entry-values
3991 Set printing of frame argument values at function entry. In some cases
3992 GDB can determine the value of function argument which was passed by the
3993 function caller, even if the value was modified inside the called function.
3995 set debug entry-values
3996 show debug entry-values
3997 Control display of debugging info for determining frame argument values at
3998 function entry and virtual tail call frames.
4000 set basenames-may-differ
4001 show basenames-may-differ
4002 Set whether a source file may have multiple base names.
4003 (A "base name" is the name of a file with the directory part removed.
4004 Example: The base name of "/home/user/hello.c" is "hello.c".)
4005 If set, GDB will canonicalize file names (e.g., expand symlinks)
4006 before comparing them. Canonicalization is an expensive operation,
4007 but it allows the same file be known by more than one base name.
4008 If not set (the default), all source files are assumed to have just
4009 one base name, and gdb will do file name comparisons more efficiently.
4015 Set a user name and notes for the current and any future trace runs.
4016 This is useful for long-running and/or disconnected traces, to
4017 inform others (or yourself) as to who is running the trace, supply
4018 contact information, or otherwise explain what is going on.
4020 set trace-stop-notes
4021 show trace-stop-notes
4022 Set a note attached to the trace run, that is displayed when the
4023 trace has been stopped by a tstop command. This is useful for
4024 instance as an explanation, if you are stopping a trace run that was
4025 started by someone else.
4027 * New remote packets
4031 Dynamically enable a tracepoint in a started trace experiment.
4035 Dynamically disable a tracepoint in a started trace experiment.
4039 Set the user and notes of the trace run.
4043 Query the current status of a tracepoint.
4047 Query the minimum length of instruction at which a fast tracepoint may
4050 * Dcache size (number of lines) and line-size are now runtime-configurable
4051 via "set dcache line" and "set dcache line-size" commands.
4055 Texas Instruments TMS320C6x tic6x-*-*
4059 Renesas RL78 rl78-*-elf
4061 *** Changes in GDB 7.3.1
4063 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4065 *** Changes in GDB 7.3
4067 * GDB has a new command: "thread find [REGEXP]".
4068 It finds the thread id whose name, target id, or thread extra info
4069 matches the given regular expression.
4071 * The "catch syscall" command now works on mips*-linux* targets.
4073 * The -data-disassemble MI command now supports modes 2 and 3 for
4074 dumping the instruction opcodes.
4076 * New command line options
4078 -data-directory DIR Specify DIR as the "data-directory".
4079 This is mostly for testing purposes.
4081 * The "maint set python auto-load on|off" command has been renamed to
4082 "set auto-load-scripts on|off".
4084 * GDB has a new command: "set directories".
4085 It is like the "dir" command except that it replaces the
4086 source path list instead of augmenting it.
4088 * GDB now understands thread names.
4090 On GNU/Linux, "info threads" will display the thread name as set by
4091 prctl or pthread_setname_np.
4093 There is also a new command, "thread name", which can be used to
4094 assign a name internally for GDB to display.
4097 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4098 has been integrated into GDB.
4102 ** The function gdb.Write now accepts an optional keyword 'stream'.
4103 This keyword, when provided, will direct the output to either
4104 stdout, stderr, or GDB's logging output.
4106 ** Parameters can now be be sub-classed in Python, and in particular
4107 you may implement the get_set_doc and get_show_doc functions.
4108 This improves how Parameter set/show documentation is processed
4109 and allows for more dynamic content.
4111 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4112 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4113 have an is_valid method.
4115 ** Breakpoints can now be sub-classed in Python, and in particular
4116 you may implement a 'stop' function that is executed each time
4117 the inferior reaches that breakpoint.
4119 ** New function gdb.lookup_global_symbol looks up a global symbol.
4121 ** GDB values in Python are now callable if the value represents a
4122 function. For example, if 'some_value' represents a function that
4123 takes two integer parameters and returns a value, you can call
4124 that function like so:
4126 result = some_value (10,20)
4128 ** Module gdb.types has been added.
4129 It contains a collection of utilities for working with gdb.Types objects:
4130 get_basic_type, has_field, make_enum_dict.
4132 ** Module gdb.printing has been added.
4133 It contains utilities for writing and registering pretty-printers.
4134 New classes: PrettyPrinter, SubPrettyPrinter,
4135 RegexpCollectionPrettyPrinter.
4136 New function: register_pretty_printer.
4138 ** New commands "info pretty-printers", "enable pretty-printer" and
4139 "disable pretty-printer" have been added.
4141 ** gdb.parameter("directories") is now available.
4143 ** New function gdb.newest_frame returns the newest frame in the
4146 ** The gdb.InferiorThread class has a new "name" attribute. This
4147 holds the thread's name.
4149 ** Python Support for Inferior events.
4150 Python scripts can add observers to be notified of events
4151 occurring in the process being debugged.
4152 The following events are currently supported:
4153 - gdb.events.cont Continue event.
4154 - gdb.events.exited Inferior exited event.
4155 - gdb.events.stop Signal received, and Breakpoint hit events.
4159 ** GDB now puts template parameters in scope when debugging in an
4160 instantiation. For example, if you have:
4162 template<int X> int func (void) { return X; }
4164 then if you step into func<5>, "print X" will show "5". This
4165 feature requires proper debuginfo support from the compiler; it
4166 was added to GCC 4.5.
4168 ** The motion commands "next", "finish", "until", and "advance" now
4169 work better when exceptions are thrown. In particular, GDB will
4170 no longer lose control of the inferior; instead, the GDB will
4171 stop the inferior at the point at which the exception is caught.
4172 This functionality requires a change in the exception handling
4173 code that was introduced in GCC 4.5.
4175 * GDB now follows GCC's rules on accessing volatile objects when
4176 reading or writing target state during expression evaluation.
4177 One notable difference to prior behavior is that "print x = 0"
4178 no longer generates a read of x; the value of the assignment is
4179 now always taken directly from the value being assigned.
4181 * GDB now has some support for using labels in the program's source in
4182 linespecs. For instance, you can use "advance label" to continue
4183 execution to a label.
4185 * GDB now has support for reading and writing a new .gdb_index
4186 section. This section holds a fast index of DWARF debugging
4187 information and can be used to greatly speed up GDB startup and
4188 operation. See the documentation for `save gdb-index' for details.
4190 * The "watch" command now accepts an optional "-location" argument.
4191 When used, this causes GDB to watch the memory referred to by the
4192 expression. Such a watchpoint is never deleted due to it going out
4195 * GDB now supports thread debugging of core dumps on GNU/Linux.
4197 GDB now activates thread debugging using the libthread_db library
4198 when debugging GNU/Linux core dumps, similarly to when debugging
4199 live processes. As a result, when debugging a core dump file, GDB
4200 is now able to display pthread_t ids of threads. For example, "info
4201 threads" shows the same output as when debugging the process when it
4202 was live. In earlier releases, you'd see something like this:
4205 * 1 LWP 6780 main () at main.c:10
4207 While now you see this:
4210 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4212 It is also now possible to inspect TLS variables when debugging core
4215 When debugging a core dump generated on a machine other than the one
4216 used to run GDB, you may need to point GDB at the correct
4217 libthread_db library with the "set libthread-db-search-path"
4218 command. See the user manual for more details on this command.
4220 * When natively debugging programs on PowerPC BookE processors running
4221 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4222 which stop execution of the inferior whenever it executes an instruction
4223 at any address within the specified range. See the "PowerPC Embedded"
4224 section in the user manual for more details.
4226 * New features in the GDB remote stub, GDBserver
4228 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4229 and i686 LynxOS (version 5.x).
4231 ** GDBserver is now supported on Blackfin Linux.
4233 * New native configurations
4235 ia64 HP-UX ia64-*-hpux*
4239 Analog Devices, Inc. Blackfin Processor bfin-*
4241 * Ada task switching is now supported on sparc-elf targets when
4242 debugging a program using the Ravenscar Profile. For more information,
4243 see the "Tasking Support when using the Ravenscar Profile" section
4244 in the GDB user manual.
4246 * Guile support was removed.
4248 * New features in the GNU simulator
4250 ** The --map-info flag lists all known core mappings.
4252 ** CFI flashes may be simulated via the "cfi" device.
4254 *** Changes in GDB 7.2
4256 * Shared library support for remote targets by default
4258 When GDB is configured for a generic, non-OS specific target, like
4259 for example, --target=arm-eabi or one of the many *-*-elf targets,
4260 GDB now queries remote stubs for loaded shared libraries using the
4261 `qXfer:libraries:read' packet. Previously, shared library support
4262 was always disabled for such configurations.
4266 ** Argument Dependent Lookup (ADL)
4268 In C++ ADL lookup directs function search to the namespaces of its
4269 arguments even if the namespace has not been imported.
4279 Here the compiler will search for `foo' in the namespace of 'b'
4280 and find A::foo. GDB now supports this. This construct is commonly
4281 used in the Standard Template Library for operators.
4283 ** Improved User Defined Operator Support
4285 In addition to member operators, GDB now supports lookup of operators
4286 defined in a namespace and imported with a `using' directive, operators
4287 defined in the global scope, operators imported implicitly from an
4288 anonymous namespace, and the ADL operators mentioned in the previous
4290 GDB now also supports proper overload resolution for all the previously
4291 mentioned flavors of operators.
4293 ** static const class members
4295 Printing of static const class members that are initialized in the
4296 class definition has been fixed.
4298 * Windows Thread Information Block access.
4300 On Windows targets, GDB now supports displaying the Windows Thread
4301 Information Block (TIB) structure. This structure is visible either
4302 by using the new command `info w32 thread-information-block' or, by
4303 dereferencing the new convenience variable named `$_tlb', a
4304 thread-specific pointer to the TIB. This feature is also supported
4305 when remote debugging using GDBserver.
4307 * Static tracepoints
4309 Static tracepoints are calls in the user program into a tracing
4310 library. One such library is a port of the LTTng kernel tracer to
4311 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4312 When debugging with GDBserver, GDB now supports combining the GDB
4313 tracepoint machinery with such libraries. For example: the user can
4314 use GDB to probe a static tracepoint marker (a call from the user
4315 program into the tracing library) with the new "strace" command (see
4316 "New commands" below). This creates a "static tracepoint" in the
4317 breakpoint list, that can be manipulated with the same feature set
4318 as fast and regular tracepoints. E.g., collect registers, local and
4319 global variables, collect trace state variables, and define
4320 tracepoint conditions. In addition, the user can collect extra
4321 static tracepoint marker specific data, by collecting the new
4322 $_sdata internal variable. When analyzing the trace buffer, you can
4323 inspect $_sdata like any other variable available to GDB. For more
4324 information, see the "Tracepoints" chapter in GDB user manual. New
4325 remote packets have been defined to support static tracepoints, see
4326 the "New remote packets" section below.
4328 * Better reconstruction of tracepoints after disconnected tracing
4330 GDB will attempt to download the original source form of tracepoint
4331 definitions when starting a trace run, and then will upload these
4332 upon reconnection to the target, resulting in a more accurate
4333 reconstruction of the tracepoints that are in use on the target.
4337 You can now exercise direct control over the ways that GDB can
4338 affect your program. For instance, you can disallow the setting of
4339 breakpoints, so that the program can run continuously (assuming
4340 non-stop mode). In addition, the "observer" variable is available
4341 to switch all of the different controls; in observer mode, GDB
4342 cannot affect the target's behavior at all, which is useful for
4343 tasks like diagnosing live systems in the field.
4345 * The new convenience variable $_thread holds the number of the
4348 * New remote packets
4352 Return the address of the Windows Thread Information Block of a given thread.
4356 In response to several of the tracepoint packets, the target may now
4357 also respond with a number of intermediate `qRelocInsn' request
4358 packets before the final result packet, to have GDB handle
4359 relocating an instruction to execute at a different address. This
4360 is particularly useful for stubs that support fast tracepoints. GDB
4361 reports support for this feature in the qSupported packet.
4365 List static tracepoint markers in the target program.
4369 List static tracepoint markers at a given address in the target
4372 qXfer:statictrace:read
4374 Read the static trace data collected (by a `collect $_sdata'
4375 tracepoint action). The remote stub reports support for this packet
4376 to gdb's qSupported query.
4380 Send the current settings of GDB's permission flags.
4384 Send part of the source (textual) form of a tracepoint definition,
4385 which includes location, conditional, and action list.
4387 * The source command now accepts a -s option to force searching for the
4388 script in the source search path even if the script name specifies
4391 * New features in the GDB remote stub, GDBserver
4393 - GDBserver now support tracepoints (including fast tracepoints, and
4394 static tracepoints). The feature is currently supported by the
4395 i386-linux and amd64-linux builds. See the "Tracepoints support
4396 in gdbserver" section in the manual for more information.
4398 GDBserver JIT compiles the tracepoint's conditional agent
4399 expression bytecode into native code whenever possible for low
4400 overhead dynamic tracepoints conditionals. For such tracepoints,
4401 an expression that examines program state is evaluated when the
4402 tracepoint is reached, in order to determine whether to capture
4403 trace data. If the condition is simple and false, processing the
4404 tracepoint finishes very quickly and no data is gathered.
4406 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4407 for static tracepoints support.
4409 - GDBserver now supports x86_64 Windows 64-bit debugging.
4411 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4412 it understands register description.
4414 * The --batch flag now disables pagination and queries.
4416 * X86 general purpose registers
4418 GDB now supports reading/writing byte, word and double-word x86
4419 general purpose registers directly. This means you can use, say,
4420 $ah or $ax to refer, respectively, to the byte register AH and
4421 16-bit word register AX that are actually portions of the 32-bit
4422 register EAX or 64-bit register RAX.
4424 * The `commands' command now accepts a range of breakpoints to modify.
4425 A plain `commands' following a command that creates multiple
4426 breakpoints affects all the breakpoints set by that command. This
4427 applies to breakpoints set by `rbreak', and also applies when a
4428 single `break' command creates multiple breakpoints (e.g.,
4429 breakpoints on overloaded c++ functions).
4431 * The `rbreak' command now accepts a filename specification as part of
4432 its argument, limiting the functions selected by the regex to those
4433 in the specified file.
4435 * Support for remote debugging Windows and SymbianOS shared libraries
4436 from Unix hosts has been improved. Non Windows GDB builds now can
4437 understand target reported file names that follow MS-DOS based file
4438 system semantics, such as file names that include drive letters and
4439 use the backslash character as directory separator. This makes it
4440 possible to transparently use the "set sysroot" and "set
4441 solib-search-path" on Unix hosts to point as host copies of the
4442 target's shared libraries. See the new command "set
4443 target-file-system-kind" described below, and the "Commands to
4444 specify files" section in the user manual for more information.
4448 eval template, expressions...
4449 Convert the values of one or more expressions under the control
4450 of the string template to a command line, and call it.
4452 set target-file-system-kind unix|dos-based|auto
4453 show target-file-system-kind
4454 Set or show the assumed file system kind for target reported file
4457 save breakpoints <filename>
4458 Save all current breakpoint definitions to a file suitable for use
4459 in a later debugging session. To read the saved breakpoint
4460 definitions, use the `source' command.
4462 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4465 info static-tracepoint-markers
4466 Display information about static tracepoint markers in the target.
4468 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4469 Define a static tracepoint by probing a marker at the given
4470 function, line, address, or marker ID.
4474 Enable and disable observer mode.
4476 set may-write-registers on|off
4477 set may-write-memory on|off
4478 set may-insert-breakpoints on|off
4479 set may-insert-tracepoints on|off
4480 set may-insert-fast-tracepoints on|off
4481 set may-interrupt on|off
4482 Set individual permissions for GDB effects on the target. Note that
4483 some of these settings can have undesirable or surprising
4484 consequences, particularly when changed in the middle of a session.
4485 For instance, disabling the writing of memory can prevent
4486 breakpoints from being inserted, cause single-stepping to fail, or
4487 even crash your program, if you disable after breakpoints have been
4488 inserted. However, GDB should not crash.
4490 set record memory-query on|off
4491 show record memory-query
4492 Control whether to stop the inferior if memory changes caused
4493 by an instruction cannot be recorded.
4498 The disassemble command now supports "start,+length" form of two arguments.
4502 ** GDB now provides a new directory location, called the python directory,
4503 where Python scripts written for GDB can be installed. The location
4504 of that directory is <data-directory>/python, where <data-directory>
4505 is the GDB data directory. For more details, see section `Scripting
4506 GDB using Python' in the manual.
4508 ** The GDB Python API now has access to breakpoints, symbols, symbol
4509 tables, program spaces, inferiors, threads and frame's code blocks.
4510 Additionally, GDB Parameters can now be created from the API, and
4511 manipulated via set/show in the CLI.
4513 ** New functions gdb.target_charset, gdb.target_wide_charset,
4514 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4516 ** New exception gdb.GdbError.
4518 ** Pretty-printers are now also looked up in the current program space.
4520 ** Pretty-printers can now be individually enabled and disabled.
4522 ** GDB now looks for names of Python scripts to auto-load in a
4523 special section named `.debug_gdb_scripts', in addition to looking
4524 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4526 * Tracepoint actions were unified with breakpoint commands. In particular,
4527 there are no longer differences in "info break" output for breakpoints and
4528 tracepoints and the "commands" command can be used for both tracepoints and
4529 regular breakpoints.
4533 ARM Symbian arm*-*-symbianelf*
4535 * D language support.
4536 GDB now supports debugging programs written in the D programming
4539 * GDB now supports the extended ptrace interface for PowerPC which is
4540 available since Linux kernel version 2.6.34. This automatically enables
4541 any hardware breakpoints and additional hardware watchpoints available in
4542 the processor. The old ptrace interface exposes just one hardware
4543 watchpoint and no hardware breakpoints.
4545 * GDB is now able to use the Data Value Compare (DVC) register available on
4546 embedded PowerPC processors to implement in hardware simple watchpoint
4547 conditions of the form:
4549 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4551 This works in native GDB running on Linux kernels with the extended ptrace
4552 interface mentioned above.
4554 *** Changes in GDB 7.1
4558 ** Namespace Support
4560 GDB now supports importing of namespaces in C++. This enables the
4561 user to inspect variables from imported namespaces. Support for
4562 namepace aliasing has also been added. So, if a namespace is
4563 aliased in the current scope (e.g. namepace C=A; ) the user can
4564 print variables using the alias (e.g. (gdb) print C::x).
4568 All known bugs relating to the printing of virtual base class were
4569 fixed. It is now possible to call overloaded static methods using a
4574 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4575 and reinterpret_cast<> are now handled by the C++ expression parser.
4579 Xilinx MicroBlaze microblaze-*-*
4584 Xilinx MicroBlaze microblaze
4587 * Multi-program debugging.
4589 GDB now has support for multi-program (a.k.a. multi-executable or
4590 multi-exec) debugging. This allows for debugging multiple inferiors
4591 simultaneously each running a different program under the same GDB
4592 session. See "Debugging Multiple Inferiors and Programs" in the
4593 manual for more information. This implied some user visible changes
4594 in the multi-inferior support. For example, "info inferiors" now
4595 lists inferiors that are not running yet or that have exited
4596 already. See also "New commands" and "New options" below.
4598 * New tracing features
4600 GDB's tracepoint facility now includes several new features:
4602 ** Trace state variables
4604 GDB tracepoints now include support for trace state variables, which
4605 are variables managed by the target agent during a tracing
4606 experiment. They are useful for tracepoints that trigger each
4607 other, so for instance one tracepoint can count hits in a variable,
4608 and then a second tracepoint has a condition that is true when the
4609 count reaches a particular value. Trace state variables share the
4610 $-syntax of GDB convenience variables, and can appear in both
4611 tracepoint actions and condition expressions. Use the "tvariable"
4612 command to create, and "info tvariables" to view; see "Trace State
4613 Variables" in the manual for more detail.
4617 GDB now includes an option for defining fast tracepoints, which
4618 targets may implement more efficiently, such as by installing a jump
4619 into the target agent rather than a trap instruction. The resulting
4620 speedup can be by two orders of magnitude or more, although the
4621 tradeoff is that some program locations on some target architectures
4622 might not allow fast tracepoint installation, for instance if the
4623 instruction to be replaced is shorter than the jump. To request a
4624 fast tracepoint, use the "ftrace" command, with syntax identical to
4625 the regular trace command.
4627 ** Disconnected tracing
4629 It is now possible to detach GDB from the target while it is running
4630 a trace experiment, then reconnect later to see how the experiment
4631 is going. In addition, a new variable disconnected-tracing lets you
4632 tell the target agent whether to continue running a trace if the
4633 connection is lost unexpectedly.
4637 GDB now has the ability to save the trace buffer into a file, and
4638 then use that file as a target, similarly to you can do with
4639 corefiles. You can select trace frames, print data that was
4640 collected in them, and use tstatus to display the state of the
4641 tracing run at the moment that it was saved. To create a trace
4642 file, use "tsave <filename>", and to use it, do "target tfile
4645 ** Circular trace buffer
4647 You can ask the target agent to handle the trace buffer as a
4648 circular buffer, discarding the oldest trace frames to make room for
4649 newer ones, by setting circular-trace-buffer to on. This feature may
4650 not be available for all target agents.
4655 The disassemble command, when invoked with two arguments, now requires
4656 the arguments to be comma-separated.
4659 The info variables command now displays variable definitions. Files
4660 which only declare a variable are not shown.
4663 The source command is now capable of sourcing Python scripts.
4664 This feature is dependent on the debugger being build with Python
4667 Related to this enhancement is also the introduction of a new command
4668 "set script-extension" (see below).
4670 * New commands (for set/show, see "New options" below)
4672 record save [<FILENAME>]
4673 Save a file (in core file format) containing the process record
4674 execution log for replay debugging at a later time.
4676 record restore <FILENAME>
4677 Restore the process record execution log that was saved at an
4678 earlier time, for replay debugging.
4680 add-inferior [-copies <N>] [-exec <FILENAME>]
4683 clone-inferior [-copies <N>] [ID]
4684 Make a new inferior ready to execute the same program another
4685 inferior has loaded.
4690 maint info program-spaces
4691 List the program spaces loaded into GDB.
4693 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4694 show remote interrupt-sequence
4695 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4696 as the sequence to the remote target in order to interrupt the execution.
4697 Ctrl-C is a default. Some system prefers BREAK which is high level of
4698 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4699 Magic SysRq g. It is BREAK signal and character 'g'.
4701 set remote interrupt-on-connect [on | off]
4702 show remote interrupt-on-connect
4703 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4704 remote target when gdb connects to it. This is needed when you debug
4707 set remotebreak [on | off]
4709 Deprecated. Use "set/show remote interrupt-sequence" instead.
4711 tvariable $NAME [ = EXP ]
4712 Create or modify a trace state variable.
4715 List trace state variables and their values.
4717 delete tvariable $NAME ...
4718 Delete one or more trace state variables.
4721 Evaluate the given expressions without collecting anything into the
4722 trace buffer. (Valid in tracepoint actions only.)
4724 ftrace FN / FILE:LINE / *ADDR
4725 Define a fast tracepoint at the given function, line, or address.
4727 * New expression syntax
4729 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4730 GDB now parses 0b101010 identically with 42.
4734 set follow-exec-mode new|same
4735 show follow-exec-mode
4736 Control whether GDB reuses the same inferior across an exec call or
4737 creates a new one. This is useful to be able to restart the old
4738 executable after the inferior having done an exec call.
4740 set default-collect EXPR, ...
4741 show default-collect
4742 Define a list of expressions to be collected at each tracepoint.
4743 This is a useful way to ensure essential items are not overlooked,
4744 such as registers or a critical global variable.
4746 set disconnected-tracing
4747 show disconnected-tracing
4748 If set to 1, the target is instructed to continue tracing if it
4749 loses its connection to GDB. If 0, the target is to stop tracing
4752 set circular-trace-buffer
4753 show circular-trace-buffer
4754 If set to on, the target is instructed to use a circular trace buffer
4755 and discard the oldest trace frames instead of stopping the trace due
4756 to a full trace buffer. If set to off, the trace stops when the buffer
4757 fills up. Some targets may not support this.
4759 set script-extension off|soft|strict
4760 show script-extension
4761 If set to "off", the debugger does not perform any script language
4762 recognition, and all sourced files are assumed to be GDB scripts.
4763 If set to "soft" (the default), files are sourced according to
4764 filename extension, falling back to GDB scripts if the first
4766 If set to "strict", files are sourced according to filename extension.
4768 set ada trust-PAD-over-XVS on|off
4769 show ada trust-PAD-over-XVS
4770 If off, activate a workaround against a bug in the debugging information
4771 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4772 the GCC sources for more information about the GNAT encoding and
4773 PAD types in particular). It is always safe to set this option to
4774 off, but this introduces a slight performance penalty. The default
4777 * Python API Improvements
4779 ** GDB provides the new class gdb.LazyString. This is useful in
4780 some pretty-printing cases. The new method gdb.Value.lazy_string
4781 provides a simple way to create objects of this type.
4783 ** The fields returned by gdb.Type.fields now have an
4784 `is_base_class' attribute.
4786 ** The new method gdb.Type.range returns the range of an array type.
4788 ** The new method gdb.parse_and_eval can be used to parse and
4789 evaluate an expression.
4791 * New remote packets
4794 Define a trace state variable.
4797 Get the current value of a trace state variable.
4800 Set desired tracing behavior upon disconnection.
4803 Set the trace buffer to be linear or circular.
4806 Get data about the tracepoints currently in use.
4810 Process record now works correctly with hardware watchpoints.
4812 Multiple bug fixes have been made to the mips-irix port, making it
4813 much more reliable. In particular:
4814 - Debugging threaded applications is now possible again. Previously,
4815 GDB would hang while starting the program, or while waiting for
4816 the program to stop at a breakpoint.
4817 - Attaching to a running process no longer hangs.
4818 - An error occurring while loading a core file has been fixed.
4819 - Changing the value of the PC register now works again. This fixes
4820 problems observed when using the "jump" command, or when calling
4821 a function from GDB, or even when assigning a new value to $pc.
4822 - With the "finish" and "return" commands, the return value for functions
4823 returning a small array is now correctly printed.
4824 - It is now possible to break on shared library code which gets executed
4825 during a shared library init phase (code executed while executing
4826 their .init section). Previously, the breakpoint would have no effect.
4827 - GDB is now able to backtrace through the signal handler for
4828 non-threaded programs.
4830 PIE (Position Independent Executable) programs debugging is now supported.
4831 This includes debugging execution of PIC (Position Independent Code) shared
4832 libraries although for that, it should be possible to run such libraries as an
4835 *** Changes in GDB 7.0
4837 * GDB now has an interface for JIT compilation. Applications that
4838 dynamically generate code can create symbol files in memory and register
4839 them with GDB. For users, the feature should work transparently, and
4840 for JIT developers, the interface is documented in the GDB manual in the
4841 "JIT Compilation Interface" chapter.
4843 * Tracepoints may now be conditional. The syntax is as for
4844 breakpoints; either an "if" clause appended to the "trace" command,
4845 or the "condition" command is available. GDB sends the condition to
4846 the target for evaluation using the same bytecode format as is used
4847 for tracepoint actions.
4849 * The disassemble command now supports: an optional /r modifier, print the
4850 raw instructions in hex as well as in symbolic form, and an optional /m
4851 modifier to print mixed source+assembly.
4853 * Process record and replay
4855 In a architecture environment that supports ``process record and
4856 replay'', ``process record and replay'' target can record a log of
4857 the process execution, and replay it with both forward and reverse
4860 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4861 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4862 set execution-direction {forward|reverse}, for targets that support
4865 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4866 feature is available with a native GDB running on kernel version
4869 * GDB now has support for multi-byte and wide character sets on the
4870 target. Strings whose character type is wchar_t, char16_t, or
4871 char32_t are now correctly printed. GDB supports wide- and unicode-
4872 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4873 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4874 `printf'. This feature requires iconv to work properly; if your
4875 system does not have a working iconv, GDB can use GNU libiconv. See
4876 the installation instructions for more information.
4878 * GDB now supports automatic retrieval of shared library files from
4879 remote targets. To use this feature, specify a system root that begins
4880 with the `remote:' prefix, either via the `set sysroot' command or via
4881 the `--with-sysroot' configure-time option.
4883 * "info sharedlibrary" now takes an optional regex of libraries to show,
4884 and it now reports if a shared library has no debugging information.
4886 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4887 now complete on file names.
4889 * When completing in expressions, gdb will attempt to limit
4890 completions to allowable structure or union fields, where appropriate.
4891 For instance, consider:
4893 # struct example { int f1; double f2; };
4894 # struct example variable;
4897 If the user types TAB at the end of this command line, the available
4898 completions will be "f1" and "f2".
4900 * Inlined functions are now supported. They show up in backtraces, and
4901 the "step", "next", and "finish" commands handle them automatically.
4903 * GDB now supports the token-splicing (##) and stringification (#)
4904 operators when expanding macros. It also supports variable-arity
4907 * GDB now supports inspecting extra signal information, exported by
4908 the new $_siginfo convenience variable. The feature is currently
4909 implemented on linux ARM, i386 and amd64.
4911 * GDB can now display the VFP floating point registers and NEON vector
4912 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4913 can provide these registers (requires Linux 2.6.30 or later). Remote
4914 and simulator targets may also provide them.
4916 * New remote packets
4919 Search memory for a sequence of bytes.
4922 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4923 operation over reliable transport links. Use of this packet is
4924 controlled by the `set remote noack-packet' command.
4927 Kill the process with the specified process ID. Use this in preference
4928 to `k' when multiprocess protocol extensions are supported.
4931 Obtains additional operating system information
4935 Read or write additional signal information.
4937 * Removed remote protocol undocumented extension
4939 An undocumented extension to the remote protocol's `S' stop reply
4940 packet that permitted the stub to pass a process id was removed.
4941 Remote servers should use the `T' stop reply packet instead.
4943 * GDB now supports multiple function calling conventions according to the
4944 DWARF-2 DW_AT_calling_convention function attribute.
4946 * The SH target utilizes the aforementioned change to distinguish between gcc
4947 and Renesas calling convention. It also adds the new CLI commands
4948 `set/show sh calling-convention'.
4950 * GDB can now read compressed debug sections, as produced by GNU gold
4951 with the --compress-debug-sections=zlib flag.
4953 * 64-bit core files are now supported on AIX.
4955 * Thread switching is now supported on Tru64.
4957 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4958 which will be allocated using malloc later in program execution.
4960 * The qXfer:libraries:read remote protocol packet now allows passing a
4961 list of section offsets.
4963 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4964 conditions handling signals delivered during attach or thread creation
4965 have also been fixed.
4967 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4968 From the user's standpoint, all unqualified instances of True and False
4969 are treated as the standard definitions, regardless of context.
4971 * GDB now parses C++ symbol and type names more flexibly. For
4974 template<typename T> class C { };
4977 GDB will now correctly handle all of:
4979 ptype C<char const *>
4980 ptype C<char const*>
4981 ptype C<const char *>
4982 ptype C<const char*>
4984 * New features in the GDB remote stub, gdbserver
4986 - The "--wrapper" command-line argument tells gdbserver to use a
4987 wrapper program to launch programs for debugging.
4989 - On PowerPC and S/390 targets, it is now possible to use a single
4990 gdbserver executable to debug both 32-bit and 64-bit programs.
4991 (This requires gdbserver itself to be built as a 64-bit executable.)
4993 - gdbserver uses the new noack protocol mode for TCP connections to
4994 reduce communications latency, if also supported and enabled in GDB.
4996 - Support for the sparc64-linux-gnu target is now included in
4999 - The amd64-linux build of gdbserver now supports debugging both
5000 32-bit and 64-bit programs.
5002 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5003 now support hardware watchpoints, and will use them automatically
5008 GDB now has support for scripting using Python. Whether this is
5009 available is determined at configure time.
5011 New GDB commands can now be written in Python.
5013 * Ada tasking support
5015 Ada tasks can now be inspected in GDB. The following commands have
5019 Print the list of Ada tasks.
5021 Print detailed information about task number N.
5023 Print the task number of the current task.
5025 Switch the context of debugging to task number N.
5027 * Support for user-defined prefixed commands. The "define" command can
5028 add new commands to existing prefixes, e.g. "target".
5030 * Multi-inferior, multi-process debugging.
5032 GDB now has generalized support for multi-inferior debugging. See
5033 "Debugging Multiple Inferiors" in the manual for more information.
5034 Although availability still depends on target support, the command
5035 set is more uniform now. The GNU/Linux specific multi-forks support
5036 has been migrated to this new framework. This implied some user
5037 visible changes; see "New commands" and also "Removed commands"
5040 * Target descriptions can now describe the target OS ABI. See the
5041 "Target Description Format" section in the user manual for more
5044 * Target descriptions can now describe "compatible" architectures
5045 to indicate that the target can execute applications for a different
5046 architecture in addition to those for the main target architecture.
5047 See the "Target Description Format" section in the user manual for
5050 * Multi-architecture debugging.
5052 GDB now includes general supports for debugging applications on
5053 hybrid systems that use more than one single processor architecture
5054 at the same time. Each such hybrid architecture still requires
5055 specific support to be added. The only hybrid architecture supported
5056 in this version of GDB is the Cell Broadband Engine.
5058 * GDB now supports integrated debugging of Cell/B.E. applications that
5059 use both the PPU and SPU architectures. To enable support for hybrid
5060 Cell/B.E. debugging, you need to configure GDB to support both the
5061 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5062 --enable-targets configure option.
5064 * Non-stop mode debugging.
5066 For some targets, GDB now supports an optional mode of operation in
5067 which you can examine stopped threads while other threads continue
5068 to execute freely. This is referred to as non-stop mode, with the
5069 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5070 section in the user manual for more information.
5072 To be able to support remote non-stop debugging, a remote stub needs
5073 to implement the non-stop mode remote protocol extensions, as
5074 described in the "Remote Non-Stop" section of the user manual. The
5075 GDB remote stub, gdbserver, has been adjusted to support these
5076 extensions on linux targets.
5078 * New commands (for set/show, see "New options" below)
5080 catch syscall [NAME(S) | NUMBER(S)]
5081 Catch system calls. Arguments, which should be names of system
5082 calls or their numbers, mean catch only those syscalls. Without
5083 arguments, every syscall will be caught. When the inferior issues
5084 any of the specified syscalls, GDB will stop and announce the system
5085 call, both when it is called and when its call returns. This
5086 feature is currently available with a native GDB running on the
5087 Linux Kernel, under the following architectures: x86, x86_64,
5088 PowerPC and PowerPC64.
5090 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5092 Search memory for a sequence of bytes.
5094 maint set python print-stack
5095 maint show python print-stack
5096 Show a stack trace when an error is encountered in a Python script.
5099 Invoke CODE by passing it to the Python interpreter.
5104 These allow macros to be defined, undefined, and listed
5108 Show operating system information about processes.
5111 List the inferiors currently under GDB's control.
5114 Switch focus to inferior number NUM.
5117 Detach from inferior number NUM.
5120 Kill inferior number NUM.
5124 set spu stop-on-load
5125 show spu stop-on-load
5126 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5128 set spu auto-flush-cache
5129 show spu auto-flush-cache
5130 Control whether to automatically flush the software-managed cache
5131 during Cell/B.E. debugging.
5133 set sh calling-convention
5134 show sh calling-convention
5135 Control the calling convention used when calling SH target functions.
5138 show debug timestamp
5139 Control display of timestamps with GDB debugging output.
5141 set disassemble-next-line
5142 show disassemble-next-line
5143 Control display of disassembled source lines or instructions when
5146 set remote noack-packet
5147 show remote noack-packet
5148 Set/show the use of remote protocol QStartNoAckMode packet. See above
5149 under "New remote packets."
5151 set remote query-attached-packet
5152 show remote query-attached-packet
5153 Control use of remote protocol `qAttached' (query-attached) packet.
5155 set remote read-siginfo-object
5156 show remote read-siginfo-object
5157 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5160 set remote write-siginfo-object
5161 show remote write-siginfo-object
5162 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5165 set remote reverse-continue
5166 show remote reverse-continue
5167 Control use of remote protocol 'bc' (reverse-continue) packet.
5169 set remote reverse-step
5170 show remote reverse-step
5171 Control use of remote protocol 'bs' (reverse-step) packet.
5173 set displaced-stepping
5174 show displaced-stepping
5175 Control displaced stepping mode. Displaced stepping is a way to
5176 single-step over breakpoints without removing them from the debuggee.
5177 Also known as "out-of-line single-stepping".
5180 show debug displaced
5181 Control display of debugging info for displaced stepping.
5183 maint set internal-error
5184 maint show internal-error
5185 Control what GDB does when an internal error is detected.
5187 maint set internal-warning
5188 maint show internal-warning
5189 Control what GDB does when an internal warning is detected.
5194 Use a wrapper program to launch programs for debugging.
5196 set multiple-symbols (all|ask|cancel)
5197 show multiple-symbols
5198 The value of this variable can be changed to adjust the debugger behavior
5199 when an expression or a breakpoint location contains an ambiguous symbol
5200 name (an overloaded function name, for instance).
5202 set breakpoint always-inserted
5203 show breakpoint always-inserted
5204 Keep breakpoints always inserted in the target, as opposed to inserting
5205 them when resuming the target, and removing them when the target stops.
5206 This option can improve debugger performance on slow remote targets.
5208 set arm fallback-mode (arm|thumb|auto)
5209 show arm fallback-mode
5210 set arm force-mode (arm|thumb|auto)
5212 These commands control how ARM GDB determines whether instructions
5213 are ARM or Thumb. The default for both settings is auto, which uses
5214 the current CPSR value for instructions without symbols; previous
5215 versions of GDB behaved as if "set arm fallback-mode arm".
5217 set disable-randomization
5218 show disable-randomization
5219 Standalone programs run with the virtual address space randomization enabled
5220 by default on some platforms. This option keeps the addresses stable across
5221 multiple debugging sessions.
5225 Control whether other threads are stopped or not when some thread hits
5230 Requests that asynchronous execution is enabled in the target, if available.
5231 In this case, it's possible to resume target in the background, and interact
5232 with GDB while the target is running. "show target-async" displays the
5233 current state of asynchronous execution of the target.
5235 set target-wide-charset
5236 show target-wide-charset
5237 The target-wide-charset is the name of the character set that GDB
5238 uses when printing characters whose type is wchar_t.
5240 set tcp auto-retry (on|off)
5242 set tcp connect-timeout
5243 show tcp connect-timeout
5244 These commands allow GDB to retry failed TCP connections to a remote stub
5245 with a specified timeout period; this is useful if the stub is launched
5246 in parallel with GDB but may not be ready to accept connections immediately.
5248 set libthread-db-search-path
5249 show libthread-db-search-path
5250 Control list of directories which GDB will search for appropriate
5253 set schedule-multiple (on|off)
5254 show schedule-multiple
5255 Allow GDB to resume all threads of all processes or only threads of
5256 the current process.
5260 Use more aggressive caching for accesses to the stack. This improves
5261 performance of remote debugging (particularly backtraces) without
5262 affecting correctness.
5264 set interactive-mode (on|off|auto)
5265 show interactive-mode
5266 Control whether GDB runs in interactive mode (on) or not (off).
5267 When in interactive mode, GDB waits for the user to answer all
5268 queries. Otherwise, GDB does not wait and assumes the default
5269 answer. When set to auto (the default), GDB determines which
5270 mode to use based on the stdin settings.
5275 For program forks, this is replaced by the new more generic `info
5276 inferiors' command. To list checkpoints, you can still use the
5277 `info checkpoints' command, which was an alias for the `info forks'
5281 Replaced by the new `inferior' command. To switch between
5282 checkpoints, you can still use the `restart' command, which was an
5283 alias for the `fork' command.
5286 This is removed, since some targets don't have a notion of
5287 processes. To switch between processes, you can still use the
5288 `inferior' command using GDB's own inferior number.
5291 For program forks, this is replaced by the new more generic `kill
5292 inferior' command. To delete a checkpoint, you can still use the
5293 `delete checkpoint' command, which was an alias for the `delete
5297 For program forks, this is replaced by the new more generic `detach
5298 inferior' command. To detach a checkpoint, you can still use the
5299 `detach checkpoint' command, which was an alias for the `detach
5302 * New native configurations
5304 x86/x86_64 Darwin i[34567]86-*-darwin*
5306 x86_64 MinGW x86_64-*-mingw*
5310 Lattice Mico32 lm32-*
5311 x86 DICOS i[34567]86-*-dicos*
5312 x86_64 DICOS x86_64-*-dicos*
5315 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5316 (mingw32ce) debugging.
5322 These commands were actually not implemented on any target.
5324 *** Changes in GDB 6.8
5326 * New native configurations
5328 NetBSD/hppa hppa*-*netbsd*
5329 Xtensa GNU/Linux xtensa*-*-linux*
5333 NetBSD/hppa hppa*-*-netbsd*
5334 Xtensa GNU/Linux xtensa*-*-linux*
5336 * Change in command line behavior -- corefiles vs. process ids.
5338 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5339 attaching to process NUMBER fails, GDB no longer attempts to open a
5340 core file named NUMBER. Attaching to a program using the -c option
5341 is no longer supported. Instead, use the '-p' or '--pid' options.
5343 * GDB can now be built as a native debugger for debugging Windows x86
5344 (mingw32) Portable Executable (PE) programs.
5346 * Pending breakpoints no longer change their number when their address
5349 * GDB now supports breakpoints with multiple locations,
5350 including breakpoints on C++ constructors, inside C++ templates,
5351 and in inlined functions.
5353 * GDB's ability to debug optimized code has been improved. GDB more
5354 accurately identifies function bodies and lexical blocks that occupy
5355 more than one contiguous range of addresses.
5357 * Target descriptions can now describe registers for PowerPC.
5359 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5360 registers on PowerPC targets.
5362 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5363 targets even when the libthread_db library is not available.
5365 * The GDB remote stub, gdbserver, now supports the new file transfer
5366 commands (remote put, remote get, and remote delete).
5368 * The GDB remote stub, gdbserver, now supports run and attach in
5369 extended-remote mode.
5371 * hppa*64*-*-hpux11* target broken
5372 The debugger is unable to start a program and fails with the following
5373 error: "Error trying to get information about dynamic linker".
5374 The gdb-6.7 release is also affected.
5376 * GDB now supports the --enable-targets= configure option to allow
5377 building a single GDB executable that supports multiple remote
5378 target architectures.
5380 * GDB now supports debugging C and C++ programs which use the
5381 Decimal Floating Point extension. In addition, the PowerPC target
5382 now has a set of pseudo-registers to inspect decimal float values
5383 stored in two consecutive float registers.
5385 * The -break-insert MI command can optionally create pending
5388 * Improved support for debugging Ada
5389 Many improvements to the Ada language support have been made. These
5391 - Better support for Ada2005 interface types
5392 - Improved handling of arrays and slices in general
5393 - Better support for Taft-amendment types
5394 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5396 - Improved command completion in Ada
5399 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5404 set print frame-arguments (all|scalars|none)
5405 show print frame-arguments
5406 The value of this variable can be changed to control which argument
5407 values should be printed by the debugger when displaying a frame.
5412 Transfer files to and from a remote target, and delete remote files.
5419 Transfer files to and from a remote target, and delete remote files.
5421 * New remote packets
5428 Open, close, read, write, and delete files on the remote system.
5431 Attach to an existing process on the remote system, in extended-remote
5435 Run a new process on the remote system, in extended-remote mode.
5437 *** Changes in GDB 6.7
5439 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5440 bfd, libiberty and opcodes, as revealed by static analysis donated by
5441 Coverity, Inc. (http://scan.coverity.com).
5443 * When looking up multiply-defined global symbols, GDB will now prefer the
5444 symbol definition in the current shared library if it was built using the
5445 -Bsymbolic linker option.
5447 * When the Text User Interface (TUI) is not configured, GDB will now
5448 recognize the -tui command-line option and print a message that the TUI
5451 * The GDB remote stub, gdbserver, now has lower overhead for high
5452 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5454 * GDB for MIPS targets now autodetects whether a remote target provides
5455 32-bit or 64-bit register values.
5457 * Support for C++ member pointers has been improved.
5459 * GDB now understands XML target descriptions, which specify the
5460 target's overall architecture. GDB can read a description from
5461 a local file or over the remote serial protocol.
5463 * Vectors of single-byte data use a new integer type which is not
5464 automatically displayed as character or string data.
5466 * The /s format now works with the print command. It displays
5467 arrays of single-byte integers and pointers to single-byte integers
5470 * Target descriptions can now describe target-specific registers,
5471 for architectures which have implemented the support (currently
5472 only ARM, M68K, and MIPS).
5474 * GDB and the GDB remote stub, gdbserver, now support the XScale
5477 * The GDB remote stub, gdbserver, has been updated to support
5478 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5479 has been rewritten to use the standard GDB remote protocol.
5481 * GDB can now step into C++ functions which are called through thunks.
5483 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5485 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5486 layout. It also supports a TextSeg= and DataSeg= response when only
5487 segment base addresses (rather than offsets) are available.
5489 * The /i format now outputs any trailing branch delay slot instructions
5490 immediately following the last instruction within the count specified.
5492 * The GDB remote protocol "T" stop reply packet now supports a
5493 "library" response. Combined with the new "qXfer:libraries:read"
5494 packet, this response allows GDB to debug shared libraries on targets
5495 where the operating system manages the list of loaded libraries (e.g.
5496 Windows and SymbianOS).
5498 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5499 (DLLs) on Windows and Windows CE targets.
5501 * GDB now supports a faster verification that a .debug file matches its binary
5502 according to its build-id signature, if the signature is present.
5508 Enable or disable hardware flow control (RTS/CTS) on the serial port
5509 when debugging using remote targets.
5511 set mem inaccessible-by-default
5512 show mem inaccessible-by-default
5513 If the target supplies a memory map, for instance via the remote
5514 protocol's "qXfer:memory-map:read" packet, setting this variable
5515 prevents GDB from accessing memory outside the memory map. This
5516 is useful for targets with memory mapped registers or which react
5517 badly to accesses of unmapped address space.
5519 set breakpoint auto-hw
5520 show breakpoint auto-hw
5521 If the target supplies a memory map, for instance via the remote
5522 protocol's "qXfer:memory-map:read" packet, setting this variable
5523 lets GDB use hardware breakpoints automatically for memory regions
5524 where it can not use software breakpoints. This covers both the
5525 "break" command and internal breakpoints used for other commands
5526 including "next" and "finish".
5529 catch exception unhandled
5530 Stop the program execution when Ada exceptions are raised.
5533 Stop the program execution when an Ada assertion failed.
5537 Set an alternate system root for target files. This is a more
5538 general version of "set solib-absolute-prefix", which is now
5539 an alias to "set sysroot".
5542 Provide extended SPU facility status information. This set of
5543 commands is available only when debugging the Cell/B.E. SPU
5546 * New native configurations
5548 OpenBSD/sh sh*-*openbsd*
5551 unset tdesc filename
5553 Use the specified local file as an XML target description, and do
5554 not query the target for its built-in description.
5558 OpenBSD/sh sh*-*-openbsd*
5559 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5560 Toshiba Media Processor mep-elf
5562 * New remote packets
5565 Ignore the specified signals; pass them directly to the debugged program
5566 without stopping other threads or reporting them to GDB.
5568 qXfer:features:read:
5569 Read an XML target description from the target, which describes its
5574 Read or write contents of an spufs file on the target system. These
5575 packets are available only on the Cell/B.E. SPU architecture.
5577 qXfer:libraries:read:
5578 Report the loaded shared libraries. Combined with new "T" packet
5579 response, this packet allows GDB to debug shared libraries on
5580 targets where the operating system manages the list of loaded
5581 libraries (e.g. Windows and SymbianOS).
5585 Support for these obsolete configurations has been removed.
5593 i[34567]86-*-lynxos*
5594 i[34567]86-*-netware*
5595 i[34567]86-*-sco3.2v5*
5596 i[34567]86-*-sco3.2v4*
5598 i[34567]86-*-sysv4.2*
5601 i[34567]86-*-unixware2*
5602 i[34567]86-*-unixware*
5611 * Other removed features
5618 Various m68k-only ROM monitors.
5625 Various Renesas ROM monitors and debugging interfaces for SH and
5630 Support for a Macraigor serial interface to on-chip debugging.
5631 GDB does not directly support the newer parallel or USB
5636 A debug information format. The predecessor to DWARF 2 and
5637 DWARF 3, which are still supported.
5639 Support for the HP aCC compiler on HP-UX/PA-RISC
5641 SOM-encapsulated symbolic debugging information, automatic
5642 invocation of pxdb, and the aCC custom C++ ABI. This does not
5643 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5644 with aCC can still be debugged on an assembly level.
5646 MIPS ".pdr" sections
5648 A MIPS-specific format used to describe stack frame layout
5649 in debugging information.
5653 GDB could work with an older version of Guile to debug
5654 the interpreter and Scheme programs running in it.
5656 set mips stack-arg-size
5657 set mips saved-gpreg-size
5659 Use "set mips abi" to control parameter passing for MIPS.
5661 *** Changes in GDB 6.6
5666 Cell Broadband Engine SPU spu-elf
5668 * GDB can now be configured as a cross-debugger targeting native Windows
5669 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5670 running on a Windows system over TCP/IP to debug Windows programs.
5672 * The GDB remote stub, gdbserver, has been updated to support Windows and
5673 Cygwin debugging. Both single-threaded and multi-threaded programs are
5676 * The "set trust-readonly-sections" command works again. This command was
5677 broken in GDB 6.3, 6.4, and 6.5.
5679 * The "load" command now supports writing to flash memory, if the remote
5680 stub provides the required support.
5682 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5683 longer requires symbolic debug information (e.g. DWARF-2).
5688 unset substitute-path
5689 show substitute-path
5690 Manage a list of substitution rules that GDB uses to rewrite the name
5691 of the directories where the sources are located. This can be useful
5692 for instance when the sources were moved to a different location
5693 between compilation and debugging.
5697 Print each CLI command as it is executed. Each command is prefixed with
5698 a number of `+' symbols representing the nesting depth.
5699 The source command now has a `-v' option to enable the same feature.
5703 The ARM Demon monitor support (RDP protocol, "target rdp").
5705 Kernel Object Display, an embedded debugging feature which only worked with
5706 an obsolete version of Cisco IOS.
5708 The 'set download-write-size' and 'show download-write-size' commands.
5710 * New remote packets
5713 Tell a stub about GDB client features, and request remote target features.
5714 The first feature implemented is PacketSize, which allows the target to
5715 specify the size of packets it can handle - to minimize the number of
5716 packets required and improve performance when connected to a remote
5720 Fetch an OS auxilliary vector from the remote stub. This packet is a
5721 more efficient replacement for qPart:auxv:read.
5723 qXfer:memory-map:read:
5724 Fetch a memory map from the remote stub, including information about
5725 RAM, ROM, and flash memory devices.
5730 Erase and program a flash memory device.
5732 * Removed remote packets
5735 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5736 used it, and only gdbserver implemented it.
5738 *** Changes in GDB 6.5
5742 Renesas M32C/M16C m32c-elf
5744 Morpho Technologies ms1 ms1-elf
5748 init-if-undefined Initialize a convenience variable, but
5749 only if it doesn't already have a value.
5751 The following commands are presently only implemented for native GNU/Linux:
5753 checkpoint Save a snapshot of the program state.
5755 restart <n> Return the program state to a
5756 previously saved state.
5758 info checkpoints List currently saved checkpoints.
5760 delete-checkpoint <n> Delete a previously saved checkpoint.
5762 set|show detach-on-fork Tell gdb whether to detach from a newly
5763 forked process, or to keep debugging it.
5765 info forks List forks of the user program that
5766 are available to be debugged.
5768 fork <n> Switch to debugging one of several
5769 forks of the user program that are
5770 available to be debugged.
5772 delete-fork <n> Delete a fork from the list of forks
5773 that are available to be debugged (and
5774 kill the forked process).
5776 detach-fork <n> Delete a fork from the list of forks
5777 that are available to be debugged (and
5778 allow the process to continue).
5782 Morpho Technologies ms2 ms1-elf
5784 * Improved Windows host support
5786 GDB now builds as a cross debugger hosted on i686-mingw32, including
5787 native console support, and remote communications using either
5788 network sockets or serial ports.
5790 * Improved Modula-2 language support
5792 GDB can now print most types in the Modula-2 syntax. This includes:
5793 basic types, set types, record types, enumerated types, range types,
5794 pointer types and ARRAY types. Procedure var parameters are correctly
5795 printed and hexadecimal addresses and character constants are also
5796 written in the Modula-2 syntax. Best results can be obtained by using
5797 GNU Modula-2 together with the -gdwarf-2 command line option.
5801 The ARM rdi-share module.
5803 The Netware NLM debug server.
5805 *** Changes in GDB 6.4
5807 * New native configurations
5809 OpenBSD/arm arm*-*-openbsd*
5810 OpenBSD/mips64 mips64-*-openbsd*
5814 Morpho Technologies ms1 ms1-elf
5816 * New command line options
5818 --batch-silent As for --batch, but totally silent.
5819 --return-child-result The debugger will exist with the same value
5820 the child (debugged) program exited with.
5821 --eval-command COMMAND, -ex COMMAND
5822 Execute a single GDB CLI command. This may be
5823 specified multiple times and in conjunction
5824 with the --command (-x) option.
5826 * Deprecated commands removed
5828 The following commands, that were deprecated in 2000, have been
5832 set|show arm disassembly-flavor set|show arm disassembler
5833 othernames set arm disassembler
5834 set|show remotedebug set|show debug remote
5835 set|show archdebug set|show debug arch
5836 set|show eventdebug set|show debug event
5839 * New BSD user-level threads support
5841 It is now possible to debug programs using the user-level threads
5842 library on OpenBSD and FreeBSD. Currently supported (target)
5845 FreeBSD/amd64 x86_64-*-freebsd*
5846 FreeBSD/i386 i386-*-freebsd*
5847 OpenBSD/i386 i386-*-openbsd*
5849 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5850 are not yet supported.
5852 * New support for Matsushita MN10300 w/sim added
5853 (Work in progress). mn10300-elf.
5855 * REMOVED configurations and files
5857 VxWorks and the XDR protocol *-*-vxworks
5858 Motorola MCORE mcore-*-*
5859 National Semiconductor NS32000 ns32k-*-*
5861 * New "set print array-indexes" command
5863 After turning this setting "on", GDB prints the index of each element
5864 when displaying arrays. The default is "off" to preserve the previous
5867 * VAX floating point support
5869 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5871 * User-defined command support
5873 In addition to using $arg0..$arg9 for argument passing, it is now possible
5874 to use $argc to determine now many arguments have been passed. See the
5875 section on user-defined commands in the user manual for more information.
5877 *** Changes in GDB 6.3:
5879 * New command line option
5881 GDB now accepts -l followed by a number to set the timeout for remote
5884 * GDB works with GCC -feliminate-dwarf2-dups
5886 GDB now supports a more compact representation of DWARF-2 debug
5887 information using DW_FORM_ref_addr references. These are produced
5888 by GCC with the option -feliminate-dwarf2-dups and also by some
5889 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5890 to use -feliminate-dwarf2-dups.
5892 * Internationalization
5894 When supported by the host system, GDB will be built with
5895 internationalization (libintl). The task of marking up the sources is
5896 continued, we're looking forward to our first translation.
5900 Initial support for debugging programs compiled with the GNAT
5901 implementation of the Ada programming language has been integrated
5902 into GDB. In this release, support is limited to expression evaluation.
5904 * New native configurations
5906 GNU/Linux/m32r m32r-*-linux-gnu
5910 GDB's remote protocol now includes support for the 'p' packet. This
5911 packet is used to fetch individual registers from a remote inferior.
5913 * END-OF-LIFE registers[] compatibility module
5915 GDB's internal register infrastructure has been completely rewritten.
5916 The new infrastructure making possible the implementation of key new
5917 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5920 GDB 6.3 will be the last release to include the registers[]
5921 compatibility module that allowed out-of-date configurations to
5922 continue to work. This change directly impacts the following
5932 powerpc bdm protocol
5934 Unless there is activity to revive these configurations, they will be
5935 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5937 * OBSOLETE configurations and files
5939 Configurations that have been declared obsolete in this release have
5940 been commented out. Unless there is activity to revive these
5941 configurations, the next release of GDB will have their sources
5942 permanently REMOVED.
5951 *** Changes in GDB 6.2.1:
5953 * MIPS `break main; run' gave an heuristic-fence-post warning
5955 When attempting to run even a simple program, a warning about
5956 heuristic-fence-post being hit would be reported. This problem has
5959 * MIPS IRIX 'long double' crashed GDB
5961 When examining a long double variable, GDB would get a segmentation
5962 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5963 IRIX long double values).
5967 A bug in the VAX stack code was causing problems with the "next"
5968 command. This problem has been fixed.
5970 *** Changes in GDB 6.2:
5972 * Fix for ``many threads''
5974 On GNU/Linux systems that use the NPTL threads library, a program
5975 rapidly creating and deleting threads would confuse GDB leading to the
5978 ptrace: No such process.
5979 thread_db_get_info: cannot get thread info: generic error
5981 This problem has been fixed.
5983 * "-async" and "-noasync" options removed.
5985 Support for the broken "-noasync" option has been removed (it caused
5988 * New ``start'' command.
5990 This command runs the program until the beginning of the main procedure.
5992 * New BSD Kernel Data Access Library (libkvm) interface
5994 Using ``target kvm'' it is now possible to debug kernel core dumps and
5995 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
5996 platforms. Currently supported (native-only) configurations are:
5998 FreeBSD/amd64 x86_64-*-freebsd*
5999 FreeBSD/i386 i?86-*-freebsd*
6000 NetBSD/i386 i?86-*-netbsd*
6001 NetBSD/m68k m68*-*-netbsd*
6002 NetBSD/sparc sparc-*-netbsd*
6003 OpenBSD/amd64 x86_64-*-openbsd*
6004 OpenBSD/i386 i?86-*-openbsd*
6005 OpenBSD/m68k m68*-openbsd*
6006 OpenBSD/sparc sparc-*-openbsd*
6008 * Signal trampoline code overhauled
6010 Many generic problems with GDB's signal handling code have been fixed.
6011 These include: backtraces through non-contiguous stacks; recognition
6012 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6013 call; backtrace through a signal trampoline; step into and out of
6014 signal handlers; and single-stepping in the signal trampoline.
6016 Please note that kernel bugs are a limiting factor here. These
6017 features have been shown to work on an s390 GNU/Linux system that
6018 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6020 * Cygwin support for DWARF 2 added.
6022 * New native configurations
6024 GNU/Linux/hppa hppa*-*-linux*
6025 OpenBSD/hppa hppa*-*-openbsd*
6026 OpenBSD/m68k m68*-*-openbsd*
6027 OpenBSD/m88k m88*-*-openbsd*
6028 OpenBSD/powerpc powerpc-*-openbsd*
6029 NetBSD/vax vax-*-netbsd*
6030 OpenBSD/vax vax-*-openbsd*
6032 * END-OF-LIFE frame compatibility module
6034 GDB's internal frame infrastructure has been completely rewritten.
6035 The new infrastructure making it possible to support key new features
6036 including DWARF 2 Call Frame Information. To aid in the task of
6037 migrating old configurations to this new infrastructure, a
6038 compatibility module, that allowed old configurations to continue to
6039 work, was also included.
6041 GDB 6.2 will be the last release to include this frame compatibility
6042 module. This change directly impacts the following configurations:
6052 Unless there is activity to revive these configurations, they will be
6053 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6055 * REMOVED configurations and files
6057 Sun 3, running SunOS 3 m68*-*-sunos3*
6058 Sun 3, running SunOS 4 m68*-*-sunos4*
6059 Sun 2, running SunOS 3 m68000-*-sunos3*
6060 Sun 2, running SunOS 4 m68000-*-sunos4*
6061 Motorola 680x0 running LynxOS m68*-*-lynxos*
6062 AT&T 3b1/Unix pc m68*-att-*
6063 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6064 decstation mips-dec-* mips-little-*
6065 riscos mips-*-riscos* mips-*-sysv*
6066 sonymips mips-sony-*
6067 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6069 *** Changes in GDB 6.1.1:
6071 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6073 The TUI (Text-mode User Interface) is now built as part of a default
6074 GDB configuration. It is enabled by either selecting the TUI with the
6075 command line option "-i=tui" or by running the separate "gdbtui"
6076 program. For more information on the TUI, see the manual "Debugging
6079 * Pending breakpoint support (also included in GDB 6.1)
6081 Support has been added to allow you to specify breakpoints in shared
6082 libraries that have not yet been loaded. If a breakpoint location
6083 cannot be found, and the "breakpoint pending" option is set to auto,
6084 GDB queries you if you wish to make the breakpoint pending on a future
6085 shared-library load. If and when GDB resolves the breakpoint symbol,
6086 the pending breakpoint is removed as one or more regular breakpoints
6089 Pending breakpoints are very useful for GCJ Java debugging.
6091 * Fixed ISO-C build problems
6093 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6094 non ISO-C code that stopped them being built using a more strict ISO-C
6095 compiler (e.g., IBM's C compiler).
6097 * Fixed build problem on IRIX 5
6099 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6100 wasn't able to compile compile on an IRIX 5 system.
6102 * Added execute permission to gdb/gdbserver/configure
6104 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6105 permission. This bug would cause configure to fail on a number of
6106 systems (Solaris, IRIX). Ref: server/519.
6108 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6110 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6111 has been updated to use constant array sizes.
6113 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6115 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6116 its generated DWARF Call Frame Info. This encoding was causing GDB to
6117 panic, that panic has been fixed. Ref: gdb/1628.
6119 * Fixed a problem when examining parameters in shared library code.
6121 When examining parameters in optimized shared library code generated
6122 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6123 not available''. GDB now correctly displays the variable's value.
6125 *** Changes in GDB 6.1:
6127 * Removed --with-mmalloc
6129 Support for the mmalloc memory manager has been removed, as it
6130 conflicted with the internal gdb byte cache.
6132 * Changes in AMD64 configurations
6134 The AMD64 target now includes the %cs and %ss registers. As a result
6135 the AMD64 remote protocol has changed; this affects the floating-point
6136 and SSE registers. If you rely on those registers for your debugging,
6137 you should upgrade gdbserver on the remote side.
6139 * Revised SPARC target
6141 The SPARC target has been completely revised, incorporating the
6142 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6143 support for LynxOS and SunOS 4 has been dropped. Calling functions
6144 from within GDB on operating systems with a non-executable stack
6145 (Solaris, OpenBSD) now works.
6149 GDB has a new C++ demangler which does a better job on the mangled
6150 names generated by current versions of g++. It also runs faster, so
6151 with this and other changes gdb should now start faster on large C++
6154 * DWARF 2 Location Expressions
6156 GDB support for location expressions has been extended to support function
6157 arguments and frame bases. Older versions of GDB could crash when they
6160 * C++ nested types and namespaces
6162 GDB's support for nested types and namespaces in C++ has been
6163 improved, especially if you use the DWARF 2 debugging format. (This
6164 is the default for recent versions of GCC on most platforms.)
6165 Specifically, if you have a class "Inner" defined within a class or
6166 namespace "Outer", then GDB realizes that the class's name is
6167 "Outer::Inner", not simply "Inner". This should greatly reduce the
6168 frequency of complaints about not finding RTTI symbols. In addition,
6169 if you are stopped at inside of a function defined within a namespace,
6170 GDB modifies its name lookup accordingly.
6172 * New native configurations
6174 NetBSD/amd64 x86_64-*-netbsd*
6175 OpenBSD/amd64 x86_64-*-openbsd*
6176 OpenBSD/alpha alpha*-*-openbsd*
6177 OpenBSD/sparc sparc-*-openbsd*
6178 OpenBSD/sparc64 sparc64-*-openbsd*
6180 * New debugging protocols
6182 M32R with SDI protocol m32r-*-elf*
6184 * "set prompt-escape-char" command deleted.
6186 The command "set prompt-escape-char" has been deleted. This command,
6187 and its very obscure effect on GDB's prompt, was never documented,
6188 tested, nor mentioned in the NEWS file.
6190 * OBSOLETE configurations and files
6192 Configurations that have been declared obsolete in this release have
6193 been commented out. Unless there is activity to revive these
6194 configurations, the next release of GDB will have their sources
6195 permanently REMOVED.
6197 Sun 3, running SunOS 3 m68*-*-sunos3*
6198 Sun 3, running SunOS 4 m68*-*-sunos4*
6199 Sun 2, running SunOS 3 m68000-*-sunos3*
6200 Sun 2, running SunOS 4 m68000-*-sunos4*
6201 Motorola 680x0 running LynxOS m68*-*-lynxos*
6202 AT&T 3b1/Unix pc m68*-att-*
6203 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6204 decstation mips-dec-* mips-little-*
6205 riscos mips-*-riscos* mips-*-sysv*
6206 sonymips mips-sony-*
6207 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6209 * REMOVED configurations and files
6211 SGI Irix-4.x mips-sgi-irix4 or iris4
6212 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6213 Z8000 simulator z8k-zilog-none or z8ksim
6214 Matsushita MN10200 w/simulator mn10200-*-*
6215 H8/500 simulator h8500-hitachi-hms or h8500hms
6216 HP/PA running BSD hppa*-*-bsd*
6217 HP/PA running OSF/1 hppa*-*-osf*
6218 HP/PA Pro target hppa*-*-pro*
6219 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6220 386BSD i[3456]86-*-bsd*
6221 Sequent family i[3456]86-sequent-sysv4*
6222 i[3456]86-sequent-sysv*
6223 i[3456]86-sequent-bsd*
6224 SPARC running LynxOS sparc-*-lynxos*
6225 SPARC running SunOS 4 sparc-*-sunos4*
6226 Tsqware Sparclet sparclet-*-*
6227 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6229 *** Changes in GDB 6.0:
6233 Support for debugging the Objective-C programming language has been
6234 integrated into GDB.
6236 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6238 DWARF 2's Call Frame Information makes available compiler generated
6239 information that more exactly describes the program's run-time stack.
6240 By using this information, GDB is able to provide more robust stack
6243 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6244 have been updated to use a new backtrace mechanism which includes
6245 DWARF 2 CFI support.
6249 GDB's remote protocol has been extended to include support for hosted
6250 file I/O (where the remote target uses GDB's file system). See GDB's
6251 remote protocol documentation for details.
6253 * All targets using the new architecture framework.
6255 All of GDB's targets have been updated to use the new internal
6256 architecture framework. The way is now open for future GDB releases
6257 to include cross-architecture native debugging support (i386 on amd64,
6260 * GNU/Linux's Thread Local Storage (TLS)
6262 GDB now includes support for for the GNU/Linux implementation of
6263 per-thread variables.
6265 * GNU/Linux's Native POSIX Thread Library (NPTL)
6267 GDB's thread code has been updated to work with either the new
6268 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6270 * Separate debug info.
6272 GDB, in conjunction with BINUTILS, now supports a mechanism for
6273 automatically loading debug information from a separate file. Instead
6274 of shipping full debug and non-debug versions of system libraries,
6275 system integrators can now instead ship just the stripped libraries
6276 and optional debug files.
6278 * DWARF 2 Location Expressions
6280 DWARF 2 Location Expressions allow the compiler to more completely
6281 describe the location of variables (even in optimized code) to the
6284 GDB now includes preliminary support for location expressions (support
6285 for DW_OP_piece is still missing).
6289 A number of long standing bugs that caused GDB to die while starting a
6290 Java application have been fixed. GDB's Java support is now
6291 considered "useable".
6293 * GNU/Linux support for fork, vfork, and exec.
6295 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6296 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6299 * GDB supports logging output to a file
6301 There are two new commands, "set logging" and "show logging", which can be
6302 used to capture GDB's output to a file.
6304 * The meaning of "detach" has changed for gdbserver
6306 The "detach" command will now resume the application, as documented. To
6307 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6310 * d10v, m68hc11 `regs' command deprecated
6312 The `info registers' command has been updated so that it displays the
6313 registers using a format identical to the old `regs' command.
6317 A new command, "maint set profile on/off", has been added. This command can
6318 be used to enable or disable profiling while running GDB, to profile a
6319 session or a set of commands. In addition there is a new configure switch,
6320 "--enable-profiling", which will cause GDB to be compiled with profiling
6321 data, for more informative profiling results.
6323 * Default MI syntax changed to "mi2".
6325 The default MI (machine interface) syntax, enabled by the command line
6326 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6327 "mi1", can be enabled by specifying the option "-i=mi1".
6329 Support for the original "mi0" syntax (included in GDB 5.0) has been
6332 Fix for gdb/192: removed extraneous space when displaying frame level.
6333 Fix for gdb/672: update changelist is now output in mi list format.
6334 Fix for gdb/702: a -var-assign that updates the value now shows up
6335 in a subsequent -var-update.
6337 * New native configurations.
6339 FreeBSD/amd64 x86_64-*-freebsd*
6341 * Multi-arched targets.
6343 HP/PA HPUX11 hppa*-*-hpux*
6344 Renesas M32R/D w/simulator m32r-*-elf*
6346 * OBSOLETE configurations and files
6348 Configurations that have been declared obsolete in this release have
6349 been commented out. Unless there is activity to revive these
6350 configurations, the next release of GDB will have their sources
6351 permanently REMOVED.
6353 Z8000 simulator z8k-zilog-none or z8ksim
6354 Matsushita MN10200 w/simulator mn10200-*-*
6355 H8/500 simulator h8500-hitachi-hms or h8500hms
6356 HP/PA running BSD hppa*-*-bsd*
6357 HP/PA running OSF/1 hppa*-*-osf*
6358 HP/PA Pro target hppa*-*-pro*
6359 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6360 Sequent family i[3456]86-sequent-sysv4*
6361 i[3456]86-sequent-sysv*
6362 i[3456]86-sequent-bsd*
6363 Tsqware Sparclet sparclet-*-*
6364 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6366 * REMOVED configurations and files
6369 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6370 IBM AIX PS/2 i[3456]86-*-aix
6371 i386 running Mach 3.0 i[3456]86-*-mach3*
6372 i386 running Mach i[3456]86-*-mach*
6373 i386 running OSF/1 i[3456]86-*osf1mk*
6374 HP/Apollo 68k Family m68*-apollo*-sysv*,
6376 m68*-hp-bsd*, m68*-hp-hpux*
6377 Argonaut Risc Chip (ARC) arc-*-*
6378 Mitsubishi D30V d30v-*-*
6379 Fujitsu FR30 fr30-*-elf*
6380 OS/9000 i[34]86-*-os9k
6381 I960 with MON960 i960-*-coff
6383 * MIPS $fp behavior changed
6385 The convenience variable $fp, for the MIPS, now consistently returns
6386 the address of the current frame's base. Previously, depending on the
6387 context, $fp could refer to either $sp or the current frame's base
6388 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6389 The GNU Source-Level Debugger''.
6391 *** Changes in GDB 5.3:
6393 * GNU/Linux shared library multi-threaded performance improved.
6395 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6396 `/proc', in preference to `ptrace' for memory reads. This may result
6397 in an improvement in the start-up time of multi-threaded, shared
6398 library applications when run under GDB. One GDB user writes: ``loads
6399 shared libs like mad''.
6401 * ``gdbserver'' now supports multi-threaded applications on some targets
6403 Support for debugging multi-threaded applications which use
6404 the GNU/Linux LinuxThreads package has been added for
6405 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6406 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6408 * GDB now supports C/C++ preprocessor macros.
6410 GDB now expands preprocessor macro invocations in C/C++ expressions,
6411 and provides various commands for showing macro definitions and how
6414 The new command `macro expand EXPRESSION' expands any macro
6415 invocations in expression, and shows the result.
6417 The new command `show macro MACRO-NAME' shows the definition of the
6418 macro named MACRO-NAME, and where it was defined.
6420 Most compilers don't include information about macros in the debugging
6421 information by default. In GCC 3.1, for example, you need to compile
6422 your program with the options `-gdwarf-2 -g3'. If the macro
6423 information is present in the executable, GDB will read it.
6425 * Multi-arched targets.
6427 DEC Alpha (partial) alpha*-*-*
6428 DEC VAX (partial) vax-*-*
6430 National Semiconductor NS32000 (partial) ns32k-*-*
6431 Motorola 68000 (partial) m68k-*-*
6432 Motorola MCORE mcore-*-*
6436 Fujitsu FRV architecture added by Red Hat frv*-*-*
6439 * New native configurations
6441 Alpha NetBSD alpha*-*-netbsd*
6442 SH NetBSD sh*-*-netbsdelf*
6443 MIPS NetBSD mips*-*-netbsd*
6444 UltraSPARC NetBSD sparc64-*-netbsd*
6446 * OBSOLETE configurations and files
6448 Configurations that have been declared obsolete in this release have
6449 been commented out. Unless there is activity to revive these
6450 configurations, the next release of GDB will have their sources
6451 permanently REMOVED.
6453 Mitsubishi D30V d30v-*-*
6454 OS/9000 i[34]86-*-os9k
6455 IBM AIX PS/2 i[3456]86-*-aix
6456 Fujitsu FR30 fr30-*-elf*
6457 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6458 Argonaut Risc Chip (ARC) arc-*-*
6459 i386 running Mach 3.0 i[3456]86-*-mach3*
6460 i386 running Mach i[3456]86-*-mach*
6461 i386 running OSF/1 i[3456]86-*osf1mk*
6462 HP/Apollo 68k Family m68*-apollo*-sysv*,
6464 m68*-hp-bsd*, m68*-hp-hpux*
6465 I960 with MON960 i960-*-coff
6467 * OBSOLETE languages
6469 CHILL, a Pascal like language used by telecommunications companies.
6471 * REMOVED configurations and files
6473 AMD 29k family via UDI a29k-amd-udi, udi29k
6474 A29K VxWorks a29k-*-vxworks
6475 AMD 29000 embedded, using EBMON a29k-none-none
6476 AMD 29000 embedded with COFF a29k-none-coff
6477 AMD 29000 embedded with a.out a29k-none-aout
6479 testsuite/gdb.hp/gdb.threads-hp/ directory
6481 * New command "set max-user-call-depth <nnn>"
6483 This command allows the user to limit the call depth of user-defined
6484 commands. The default is 1024.
6486 * Changes in FreeBSD/i386 native debugging.
6488 Support for the "generate-core-file" has been added.
6490 * New commands "dump", "append", and "restore".
6492 These commands allow data to be copied from target memory
6493 to a bfd-format or binary file (dump and append), and back
6494 from a file into memory (restore).
6496 * Improved "next/step" support on multi-processor Alpha Tru64.
6498 The previous single-step mechanism could cause unpredictable problems,
6499 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6500 of a software single-step mechanism prevents this.
6502 *** Changes in GDB 5.2.1:
6510 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6511 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6512 Fix, by Joel Brobecker imported from mainline.
6514 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6515 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6516 Fix, by Fred Fish, imported from mainline.
6518 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6519 Surprisingly enough, it works now.
6520 By Michal Ludvig, imported from mainline.
6522 i386 hardware watchpoint support:
6523 avoid misses on second run for some targets.
6524 By Pierre Muller, imported from mainline.
6526 *** Changes in GDB 5.2:
6528 * New command "set trust-readonly-sections on[off]".
6530 This command is a hint that tells gdb that read-only sections
6531 really are read-only (ie. that their contents will not change).
6532 In this mode, gdb will go to the object file rather than the
6533 target to read memory from read-only sections (such as ".text").
6534 This can be a significant performance improvement on some
6535 (notably embedded) targets.
6537 * New command "generate-core-file" (or "gcore").
6539 This new gdb command allows the user to drop a core file of the child
6540 process state at any time. So far it's been implemented only for
6541 GNU/Linux and Solaris, but should be relatively easily ported to other
6542 hosts. Argument is core file name (defaults to core.<pid>).
6544 * New command line option
6546 GDB now accepts --pid or -p followed by a process id.
6548 * Change in command line behavior -- corefiles vs. process ids.
6550 There is a subtle behavior in the way in which GDB handles
6551 command line arguments. The first non-flag argument is always
6552 a program to debug, but the second non-flag argument may either
6553 be a corefile or a process id. Previously, GDB would attempt to
6554 open the second argument as a corefile, and if that failed, would
6555 issue a superfluous error message and then attempt to attach it as
6556 a process. Now, if the second argument begins with a non-digit,
6557 it will be treated as a corefile. If it begins with a digit,
6558 GDB will attempt to attach it as a process, and if no such process
6559 is found, will then attempt to open it as a corefile.
6561 * Changes in ARM configurations.
6563 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6564 configuration is fully multi-arch.
6566 * New native configurations
6568 ARM NetBSD arm*-*-netbsd*
6569 x86 OpenBSD i[3456]86-*-openbsd*
6570 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6571 Sparc64 running FreeBSD sparc64-*-freebsd*
6575 Sanyo XStormy16 xstormy16-elf
6577 * OBSOLETE configurations and files
6579 Configurations that have been declared obsolete in this release have
6580 been commented out. Unless there is activity to revive these
6581 configurations, the next release of GDB will have their sources
6582 permanently REMOVED.
6584 AMD 29k family via UDI a29k-amd-udi, udi29k
6585 A29K VxWorks a29k-*-vxworks
6586 AMD 29000 embedded, using EBMON a29k-none-none
6587 AMD 29000 embedded with COFF a29k-none-coff
6588 AMD 29000 embedded with a.out a29k-none-aout
6590 testsuite/gdb.hp/gdb.threads-hp/ directory
6592 * REMOVED configurations and files
6594 TI TMS320C80 tic80-*-*
6596 PowerPC Solaris powerpcle-*-solaris*
6597 PowerPC Windows NT powerpcle-*-cygwin32
6598 PowerPC Netware powerpc-*-netware*
6599 Harris/CXUX m88k m88*-harris-cxux*
6600 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6601 ns32k-utek-sysv* ns32k-utek-*
6602 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6603 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6604 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6605 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6606 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6608 * Changes to command line processing
6610 The new `--args' feature can be used to specify command-line arguments
6611 for the inferior from gdb's command line.
6613 * Changes to key bindings
6615 There is a new `operate-and-get-next' function bound to `C-o'.
6617 *** Changes in GDB 5.1.1
6619 Fix compile problem on DJGPP.
6621 Fix a problem with floating-point registers on the i386 being
6624 Fix to stop GDB crashing on .debug_str debug info.
6626 Numerous documentation fixes.
6628 Numerous testsuite fixes.
6630 *** Changes in GDB 5.1:
6632 * New native configurations
6634 Alpha FreeBSD alpha*-*-freebsd*
6635 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6636 MIPS GNU/Linux mips*-*-linux*
6637 MIPS SGI Irix 6.x mips*-sgi-irix6*
6638 ia64 AIX ia64-*-aix*
6639 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6643 Motorola 68HC11 and 68HC12 m68hc11-elf
6645 UltraSparc running GNU/Linux sparc64-*-linux*
6647 * OBSOLETE configurations and files
6649 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6650 Harris/CXUX m88k m88*-harris-cxux*
6651 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6652 ns32k-utek-sysv* ns32k-utek-*
6653 TI TMS320C80 tic80-*-*
6655 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6656 PowerPC Solaris powerpcle-*-solaris*
6657 PowerPC Windows NT powerpcle-*-cygwin32
6658 PowerPC Netware powerpc-*-netware*
6659 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6660 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6661 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6662 Apple Macintosh (MPW) host N/A
6664 stuff.c (Program to stuff files into a specially prepared space in kdb)
6665 kdb-start.c (Main loop for the standalone kernel debugger)
6667 Configurations that have been declared obsolete in this release have
6668 been commented out. Unless there is activity to revive these
6669 configurations, the next release of GDB will have their sources
6670 permanently REMOVED.
6672 * REMOVED configurations and files
6674 Altos 3068 m68*-altos-*
6675 Convex c1-*-*, c2-*-*
6677 ARM RISCix arm-*-* (as host)
6681 * GDB has been converted to ISO C.
6683 GDB's source code has been converted to ISO C. In particular, the
6684 sources are fully protoized, and rely on standard headers being
6689 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6691 * The MI enabled by default.
6693 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6694 revised and enabled by default. Packages which use GDB as a debugging
6695 engine behind a UI or another front end are encouraged to switch to
6696 using the GDB/MI interface, instead of the old annotations interface
6697 which is now deprecated.
6699 * Support for debugging Pascal programs.
6701 GDB now includes support for debugging Pascal programs. The following
6702 main features are supported:
6704 - Pascal-specific data types such as sets;
6706 - automatic recognition of Pascal sources based on file-name
6709 - Pascal-style display of data types, variables, and functions;
6711 - a Pascal expression parser.
6713 However, some important features are not yet supported.
6715 - Pascal string operations are not supported at all;
6717 - there are some problems with boolean types;
6719 - Pascal type hexadecimal constants are not supported
6720 because they conflict with the internal variables format;
6722 - support for Pascal objects and classes is not full yet;
6724 - unlike Pascal, GDB is case-sensitive for symbol names.
6726 * Changes in completion.
6728 Commands such as `shell', `run' and `set args', which pass arguments
6729 to inferior programs, now complete on file names, similar to what
6730 users expect at the shell prompt.
6732 Commands which accept locations, such as `disassemble', `print',
6733 `breakpoint', `until', etc. now complete on filenames as well as
6734 program symbols. Thus, if you type "break foob TAB", and the source
6735 files linked into the programs include `foobar.c', that file name will
6736 be one of the candidates for completion. However, file names are not
6737 considered for completion after you typed a colon that delimits a file
6738 name from a name of a function in that file, as in "break foo.c:bar".
6740 `set demangle-style' completes on available demangling styles.
6742 * New platform-independent commands:
6744 It is now possible to define a post-hook for a command as well as a
6745 hook that runs before the command. For more details, see the
6746 documentation of `hookpost' in the GDB manual.
6748 * Changes in GNU/Linux native debugging.
6750 Support for debugging multi-threaded programs has been completely
6751 revised for all platforms except m68k and sparc. You can now debug as
6752 many threads as your system allows you to have.
6754 Attach/detach is supported for multi-threaded programs.
6756 Support for SSE registers was added for x86. This doesn't work for
6757 multi-threaded programs though.
6759 * Changes in MIPS configurations.
6761 Multi-arch support is enabled for all MIPS configurations.
6763 GDB can now be built as native debugger on SGI Irix 6.x systems for
6764 debugging n32 executables. (Debugging 64-bit executables is not yet
6767 * Unified support for hardware watchpoints in all x86 configurations.
6769 Most (if not all) native x86 configurations support hardware-assisted
6770 breakpoints and watchpoints in a unified manner. This support
6771 implements debug register sharing between watchpoints, which allows to
6772 put a virtually infinite number of watchpoints on the same address,
6773 and also supports watching regions up to 16 bytes with several debug
6776 The new maintenance command `maintenance show-debug-regs' toggles
6777 debugging print-outs in functions that insert, remove, and test
6778 watchpoints and hardware breakpoints.
6780 * Changes in the DJGPP native configuration.
6782 New command ``info dos sysinfo'' displays assorted information about
6783 the CPU, OS, memory, and DPMI server.
6785 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6786 display information about segment descriptors stored in GDT, LDT, and
6789 New commands ``info dos pde'' and ``info dos pte'' display entries
6790 from Page Directory and Page Tables (for now works with CWSDPMI only).
6791 New command ``info dos address-pte'' displays the Page Table entry for
6792 a given linear address.
6794 GDB can now pass command lines longer than 126 characters to the
6795 program being debugged (requires an update to the libdbg.a library
6796 which is part of the DJGPP development kit).
6798 DWARF2 debug info is now supported.
6800 It is now possible to `step' and `next' through calls to `longjmp'.
6802 * Changes in documentation.
6804 All GDB documentation was converted to GFDL, the GNU Free
6805 Documentation License.
6807 Tracepoints-related commands are now fully documented in the GDB
6810 TUI, the Text-mode User Interface, is now documented in the manual.
6812 Tracepoints-related commands are now fully documented in the GDB
6815 The "GDB Internals" manual now has an index. It also includes
6816 documentation of `ui_out' functions, GDB coding standards, x86
6817 hardware watchpoints, and memory region attributes.
6819 * GDB's version number moved to ``version.in''
6821 The Makefile variable VERSION has been replaced by the file
6822 ``version.in''. People creating GDB distributions should update the
6823 contents of this file.
6827 GUD support is now a standard part of the EMACS distribution.
6829 *** Changes in GDB 5.0:
6831 * Improved support for debugging FP programs on x86 targets
6833 Unified and much-improved support for debugging floating-point
6834 programs on all x86 targets. In particular, ``info float'' now
6835 displays the FP registers in the same format on all x86 targets, with
6836 greater level of detail.
6838 * Improvements and bugfixes in hardware-assisted watchpoints
6840 It is now possible to watch array elements, struct members, and
6841 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6842 on x86 targets no longer erroneously trigger when the address is
6845 * Improvements in the native DJGPP version of GDB
6847 The distribution now includes all the scripts and auxiliary files
6848 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6849 machines ``out of the box''.
6851 The DJGPP version can now debug programs that use signals. It is
6852 possible to catch signals that happened in the debuggee, deliver
6853 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6854 would kill the program being debugged.) Programs that hook hardware
6855 interrupts (keyboard, timer, etc.) can also be debugged.
6857 It is now possible to debug DJGPP programs that redirect their
6858 standard handles or switch them to raw (as opposed to cooked) mode, or
6859 even close them. The command ``run < foo > bar'' works as expected,
6860 and ``info terminal'' reports useful information about the debuggee's
6861 terminal, including raw/cooked mode, redirection, etc.
6863 The DJGPP version now uses termios functions for console I/O, which
6864 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6867 DOS-style file names with drive letters are now fully supported by
6870 It is now possible to debug DJGPP programs that switch their working
6871 directory. It is also possible to rerun the debuggee any number of
6872 times without restarting GDB; thus, you can use the same setup,
6873 breakpoints, etc. for many debugging sessions.
6875 * New native configurations
6877 ARM GNU/Linux arm*-*-linux*
6878 PowerPC GNU/Linux powerpc-*-linux*
6882 Motorola MCore mcore-*-*
6883 x86 VxWorks i[3456]86-*-vxworks*
6884 PowerPC VxWorks powerpc-*-vxworks*
6885 TI TMS320C80 tic80-*-*
6887 * OBSOLETE configurations
6889 Altos 3068 m68*-altos-*
6890 Convex c1-*-*, c2-*-*
6892 ARM RISCix arm-*-* (as host)
6895 Configurations that have been declared obsolete will be commented out,
6896 but the code will be left in place. If there is no activity to revive
6897 these configurations before the next release of GDB, the sources will
6898 be permanently REMOVED.
6900 * Gould support removed
6902 Support for the Gould PowerNode and NP1 has been removed.
6904 * New features for SVR4
6906 On SVR4 native platforms (such as Solaris), if you attach to a process
6907 without first loading a symbol file, GDB will now attempt to locate and
6908 load symbols from the running process's executable file.
6910 * Many C++ enhancements
6912 C++ support has been greatly improved. Overload resolution now works properly
6913 in almost all cases. RTTI support is on the way.
6915 * Remote targets can connect to a sub-program
6917 A popen(3) style serial-device has been added. This device starts a
6918 sub-process (such as a stand-alone simulator) and then communicates
6919 with that. The sub-program to run is specified using the syntax
6920 ``|<program> <args>'' vis:
6922 (gdb) set remotedebug 1
6923 (gdb) target extended-remote |mn10300-elf-sim program-args
6925 * MIPS 64 remote protocol
6927 A long standing bug in the mips64 remote protocol where by GDB
6928 expected certain 32 bit registers (ex SR) to be transfered as 32
6929 instead of 64 bits has been fixed.
6931 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6932 added to provide backward compatibility with older versions of GDB.
6934 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6936 The command ``set remotebinarydownload'' command has been replaced by
6937 ``set remote X-packet''. Other commands in ``set remote'' family
6938 include ``set remote P-packet''.
6940 * Breakpoint commands accept ranges.
6942 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6943 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6944 ``tracepoint passcount'' also accepts a range of tracepoints.
6946 * ``apropos'' command added.
6948 The ``apropos'' command searches through command names and
6949 documentation strings, printing out matches, making it much easier to
6950 try to find a command that does what you are looking for.
6954 A new machine oriented interface (MI) has been added to GDB. This
6955 interface is designed for debug environments running GDB as a separate
6956 process. This is part of the long term libGDB project. See the
6957 "GDB/MI" chapter of the GDB manual for further information. It can be
6958 enabled by configuring with:
6960 .../configure --enable-gdbmi
6962 *** Changes in GDB-4.18:
6964 * New native configurations
6966 HP-UX 10.20 hppa*-*-hpux10.20
6967 HP-UX 11.x hppa*-*-hpux11.0*
6968 M68K GNU/Linux m68*-*-linux*
6972 Fujitsu FR30 fr30-*-elf*
6973 Intel StrongARM strongarm-*-*
6974 Mitsubishi D30V d30v-*-*
6976 * OBSOLETE configurations
6978 Gould PowerNode, NP1 np1-*-*, pn-*-*
6980 Configurations that have been declared obsolete will be commented out,
6981 but the code will be left in place. If there is no activity to revive
6982 these configurations before the next release of GDB, the sources will
6983 be permanently REMOVED.
6987 As a compatibility experiment, GDB's source files buildsym.h and
6988 buildsym.c have been converted to pure standard C, no longer
6989 containing any K&R compatibility code. We believe that all systems in
6990 use today either come with a standard C compiler, or have a GCC port
6991 available. If this is not true, please report the affected
6992 configuration to bug-gdb@gnu.org immediately. See the README file for
6993 information about getting a standard C compiler if you don't have one
6998 GDB now uses readline 2.2.
7000 * set extension-language
7002 You can now control the mapping between filename extensions and source
7003 languages by using the `set extension-language' command. For instance,
7004 you can ask GDB to treat .c files as C++ by saying
7005 set extension-language .c c++
7006 The command `info extensions' lists all of the recognized extensions
7007 and their associated languages.
7009 * Setting processor type for PowerPC and RS/6000
7011 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7012 you can use the `set processor' command to specify what variant of the
7013 PowerPC family you are debugging. The command
7017 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7018 following PowerPC and RS6000 variants:
7020 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7021 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7023 403GC IBM PowerPC 403GC
7024 505 Motorola PowerPC 505
7025 860 Motorola PowerPC 860 or 850
7026 601 Motorola PowerPC 601
7027 602 Motorola PowerPC 602
7028 603 Motorola/IBM PowerPC 603 or 603e
7029 604 Motorola PowerPC 604 or 604e
7030 750 Motorola/IBM PowerPC 750 or 750
7032 At the moment, this command just tells GDB what to name the
7033 special-purpose processor registers. Since almost all the affected
7034 registers are inaccessible to user-level programs, this command is
7035 only useful for remote debugging in its present form.
7039 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7040 more extensive support for HP-UX. Added features include shared
7041 library support, kernel threads and hardware watchpoints for 11.00,
7042 support for HP's ANSI C and C++ compilers, and a compatibility mode
7043 for xdb and dbx commands.
7047 HP's donation includes the new concept of catchpoints, which is a
7048 generalization of the old catch command. On HP-UX, it is now possible
7049 to catch exec, fork, and vfork, as well as library loading.
7051 This means that the existing catch command has changed; its first
7052 argument now specifies the type of catch to be set up. See the
7053 output of "help catch" for a list of catchpoint types.
7055 * Debugging across forks
7057 On HP-UX, you can choose which process to debug when a fork() happens
7062 HP has donated a curses-based terminal user interface (TUI). To get
7063 it, build with --enable-tui. Although this can be enabled for any
7064 configuration, at present it only works for native HP debugging.
7066 * GDB remote protocol additions
7068 A new protocol packet 'X' that writes binary data is now available.
7069 Default behavior is to try 'X', then drop back to 'M' if the stub
7070 fails to respond. The settable variable `remotebinarydownload'
7071 allows explicit control over the use of 'X'.
7073 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7074 full 64-bit address. The command
7076 set remoteaddresssize 32
7078 can be used to revert to the old behaviour. For existing remote stubs
7079 the change should not be noticed, as the additional address information
7082 In order to assist in debugging stubs, you may use the maintenance
7083 command `packet' to send any text string to the stub. For instance,
7085 maint packet heythere
7087 sends the packet "$heythere#<checksum>". Note that it is very easy to
7088 disrupt a debugging session by sending the wrong packet at the wrong
7091 The compare-sections command allows you to compare section data on the
7092 target to what is in the executable file without uploading or
7093 downloading, by comparing CRC checksums.
7095 * Tracing can collect general expressions
7097 You may now collect general expressions at tracepoints. This requires
7098 further additions to the target-side stub; see tracepoint.c and
7099 doc/agentexpr.texi for further details.
7101 * mask-address variable for Mips
7103 For Mips targets, you may control the zeroing of the upper 32 bits of
7104 a 64-bit address by entering `set mask-address on'. This is mainly
7105 of interest to users of embedded R4xxx and R5xxx processors.
7107 * Higher serial baud rates
7109 GDB's serial code now allows you to specify baud rates 57600, 115200,
7110 230400, and 460800 baud. (Note that your host system may not be able
7111 to achieve all of these rates.)
7115 The i960 configuration now includes an initial implementation of a
7116 builtin simulator, contributed by Jim Wilson.
7119 *** Changes in GDB-4.17:
7121 * New native configurations
7123 Alpha GNU/Linux alpha*-*-linux*
7124 Unixware 2.x i[3456]86-unixware2*
7125 Irix 6.x mips*-sgi-irix6*
7126 PowerPC GNU/Linux powerpc-*-linux*
7127 PowerPC Solaris powerpcle-*-solaris*
7128 Sparc GNU/Linux sparc-*-linux*
7129 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7133 Argonaut Risc Chip (ARC) arc-*-*
7134 Hitachi H8/300S h8300*-*-*
7135 Matsushita MN10200 w/simulator mn10200-*-*
7136 Matsushita MN10300 w/simulator mn10300-*-*
7137 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7138 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7139 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7140 Mitsubishi D10V w/simulator d10v-*-*
7141 Mitsubishi M32R/D w/simulator m32r-*-elf*
7142 Tsqware Sparclet sparclet-*-*
7143 NEC V850 w/simulator v850-*-*
7145 * New debugging protocols
7147 ARM with RDI protocol arm*-*-*
7148 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7149 DDB and LSI variants of PMON protocol mips*-*-*
7150 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7151 PowerPC with SDS protocol powerpc{,le}-*-eabi
7152 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7156 All configurations can now understand and use the DWARF 2 debugging
7157 format. The choice is automatic, if the symbol file contains DWARF 2
7162 GDB now includes basic Java language support. This support is
7163 only useful with Java compilers that produce native machine code.
7165 * solib-absolute-prefix and solib-search-path
7167 For SunOS and SVR4 shared libraries, you may now set the prefix for
7168 loading absolute shared library symbol files, and the search path for
7169 locating non-absolute shared library symbol files.
7171 * Live range splitting
7173 GDB can now effectively debug code for which GCC has performed live
7174 range splitting as part of its optimization. See gdb/doc/LRS for
7175 more details on the expected format of the stabs information.
7179 GDB's support for the GNU Hurd, including thread debugging, has been
7180 updated to work with current versions of the Hurd.
7184 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7185 instruction set. ARM GDB automatically detects when Thumb
7186 instructions are in use, and adjusts disassembly and backtracing
7191 GDB's MIPS target configurations now handle the MIP16 16-bit
7196 GDB now includes support for overlays; if an executable has been
7197 linked such that multiple sections are based at the same address, GDB
7198 will decide which section to use for symbolic info. You can choose to
7199 control the decision manually, using overlay commands, or implement
7200 additional target-side support and use "overlay load-target" to bring
7201 in the overlay mapping. Do "help overlay" for more detail.
7205 The command "info symbol <address>" displays information about
7206 the symbol at the specified address.
7210 The standard remote protocol now includes an extension that allows
7211 asynchronous collection and display of trace data. This requires
7212 extensive support in the target-side debugging stub. Tracing mode
7213 includes a new interaction mode in GDB and new commands: see the
7214 file tracepoint.c for more details.
7218 Configurations for embedded MIPS now include a simulator contributed
7219 by Cygnus Solutions. The simulator supports the instruction sets
7220 of most MIPS variants.
7224 Sparc configurations may now include the ERC32 simulator contributed
7225 by the European Space Agency. The simulator is not built into
7226 Sparc targets by default; configure with --enable-sim to include it.
7230 For target configurations that may include multiple variants of a
7231 basic architecture (such as MIPS and SH), you may now set the
7232 architecture explicitly. "set arch" sets, "info arch" lists
7233 the possible architectures.
7235 *** Changes in GDB-4.16:
7237 * New native configurations
7239 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7240 M68K NetBSD m68k-*-netbsd*
7241 PowerPC AIX 4.x powerpc-*-aix*
7242 PowerPC MacOS powerpc-*-macos*
7243 PowerPC Windows NT powerpcle-*-cygwin32
7244 RS/6000 AIX 4.x rs6000-*-aix4*
7248 ARM with RDP protocol arm-*-*
7249 I960 with MON960 i960-*-coff
7250 MIPS VxWorks mips*-*-vxworks*
7251 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7252 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7254 Matra Sparclet sparclet-*-*
7258 The powerpc-eabi configuration now includes the PSIM simulator,
7259 contributed by Andrew Cagney, with assistance from Mike Meissner.
7260 PSIM is a very elaborate model of the PowerPC, including not only
7261 basic instruction set execution, but also details of execution unit
7262 performance and I/O hardware. See sim/ppc/README for more details.
7266 GDB now works with Solaris 2.5.
7268 * Windows 95/NT native
7270 GDB will now work as a native debugger on Windows 95 and Windows NT.
7271 To build it from source, you must use the "gnu-win32" environment,
7272 which uses a DLL to emulate enough of Unix to run the GNU tools.
7273 Further information, binaries, and sources are available at
7274 ftp.cygnus.com, under pub/gnu-win32.
7276 * dont-repeat command
7278 If a user-defined command includes the command `dont-repeat', then the
7279 command will not be repeated if the user just types return. This is
7280 useful if the command is time-consuming to run, so that accidental
7281 extra keystrokes don't run the same command many times.
7283 * Send break instead of ^C
7285 The standard remote protocol now includes an option to send a break
7286 rather than a ^C to the target in order to interrupt it. By default,
7287 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7289 * Remote protocol timeout
7291 The standard remote protocol includes a new variable `remotetimeout'
7292 that allows you to set the number of seconds before GDB gives up trying
7293 to read from the target. The default value is 2.
7295 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7297 By default GDB will automatically keep track of objects as they are
7298 loaded and unloaded by the dynamic linker. By using the command `set
7299 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7300 when shared library events occur, thus allowing you to set breakpoints
7301 in shared libraries which are explicitly loaded by the inferior.
7303 Note this feature does not work on hpux8. On hpux9 you must link
7304 /usr/lib/end.o into your program. This feature should work
7305 automatically on hpux10.
7307 * Irix 5.x hardware watchpoint support
7309 Irix 5 configurations now support the use of hardware watchpoints.
7311 * Mips protocol "SYN garbage limit"
7313 When debugging a Mips target using the `target mips' protocol, you
7314 may set the number of characters that GDB will ignore by setting
7315 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7316 every character. The default value is 1050.
7318 * Recording and replaying remote debug sessions
7320 If you set `remotelogfile' to the name of a file, gdb will write to it
7321 a recording of a remote debug session. This recording may then be
7322 replayed back to gdb using "gdbreplay". See gdbserver/README for
7323 details. This is useful when you have a problem with GDB while doing
7324 remote debugging; you can make a recording of the session and send it
7325 to someone else, who can then recreate the problem.
7327 * Speedups for remote debugging
7329 GDB includes speedups for downloading and stepping MIPS systems using
7330 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7331 and more efficient S-record downloading.
7333 * Memory use reductions and statistics collection
7335 GDB now uses less memory and reports statistics about memory usage.
7336 Try the `maint print statistics' command, for example.
7338 *** Changes in GDB-4.15:
7340 * Psymtabs for XCOFF
7342 The symbol reader for AIX GDB now uses partial symbol tables. This
7343 can greatly improve startup time, especially for large executables.
7345 * Remote targets use caching
7347 Remote targets now use a data cache to speed up communication with the
7348 remote side. The data cache could lead to incorrect results because
7349 it doesn't know about volatile variables, thus making it impossible to
7350 debug targets which use memory mapped I/O devices. `set remotecache
7351 off' turns the data cache off.
7353 * Remote targets may have threads
7355 The standard remote protocol now includes support for multiple threads
7356 in the target system, using new protocol commands 'H' and 'T'. See
7357 gdb/remote.c for details.
7361 If GDB is configured with `--enable-netrom', then it will include
7362 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7363 acts as though it is a bank of ROM on the target board, but you can
7364 write into it over the network. GDB's support consists only of
7365 support for fast loading into the emulated ROM; to debug, you must use
7366 another protocol, such as standard remote protocol. The usual
7367 sequence is something like
7369 target nrom <netrom-hostname>
7371 target remote <netrom-hostname>:1235
7375 GDB now includes support for the Apple Macintosh, as a host only. It
7376 may be run as either an MPW tool or as a standalone application, and
7377 it can debug through the serial port. All the usual GDB commands are
7378 available, but to the target command, you must supply "serial" as the
7379 device type instead of "/dev/ttyXX". See mpw-README in the main
7380 directory for more information on how to build. The MPW configuration
7381 scripts */mpw-config.in support only a few targets, and only the
7382 mips-idt-ecoff target has been tested.
7386 GDB configuration now uses autoconf. This is not user-visible,
7387 but does simplify configuration and building.
7391 GDB now supports hpux10.
7393 *** Changes in GDB-4.14:
7395 * New native configurations
7397 x86 FreeBSD i[345]86-*-freebsd
7398 x86 NetBSD i[345]86-*-netbsd
7399 NS32k NetBSD ns32k-*-netbsd
7400 Sparc NetBSD sparc-*-netbsd
7404 A29K VxWorks a29k-*-vxworks
7405 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7406 CPU32 EST-300 emulator m68*-*-est*
7407 PowerPC ELF powerpc-*-elf
7410 * Alpha OSF/1 support for procfs
7412 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7413 possible to attach to running processes. As the mounting of the /proc
7414 filesystem is optional on the Alpha, GDB automatically determines
7415 the availability of /proc during startup. This can lead to problems
7416 if /proc is unmounted after GDB has been started.
7418 * Arguments to user-defined commands
7420 User commands may accept up to 10 arguments separated by whitespace.
7421 Arguments are accessed within the user command via $arg0..$arg9. A
7424 print $arg0 + $arg1 + $arg2
7426 To execute the command use:
7429 Defines the command "adder" which prints the sum of its three arguments.
7430 Note the arguments are text substitutions, so they may reference variables,
7431 use complex expressions, or even perform inferior function calls.
7433 * New `if' and `while' commands
7435 This makes it possible to write more sophisticated user-defined
7436 commands. Both commands take a single argument, which is the
7437 expression to evaluate, and must be followed by the commands to
7438 execute, one per line, if the expression is nonzero, the list being
7439 terminated by the word `end'. The `if' command list may include an
7440 `else' word, which causes the following commands to be executed only
7441 if the expression is zero.
7443 * Fortran source language mode
7445 GDB now includes partial support for Fortran 77. It will recognize
7446 Fortran programs and can evaluate a subset of Fortran expressions, but
7447 variables and functions may not be handled correctly. GDB will work
7448 with G77, but does not yet know much about symbols emitted by other
7451 * Better HPUX support
7453 Most debugging facilities now work on dynamic executables for HPPAs
7454 running hpux9 or later. You can attach to running dynamically linked
7455 processes, but by default the dynamic libraries will be read-only, so
7456 for instance you won't be able to put breakpoints in them. To change
7457 that behavior do the following before running the program:
7463 This will cause the libraries to be mapped private and read-write.
7464 To revert to the normal behavior, do this:
7470 You cannot set breakpoints or examine data in the library until after
7471 the library is loaded if the function/data symbols do not have
7474 GDB can now also read debug symbols produced by the HP C compiler on
7475 HPPAs (sorry, no C++, Fortran or 68k support).
7477 * Target byte order now dynamically selectable
7479 You can choose which byte order to use with a target system, via the
7480 commands "set endian big" and "set endian little", and you can see the
7481 current setting by using "show endian". You can also give the command
7482 "set endian auto", in which case GDB will use the byte order
7483 associated with the executable. Currently, only embedded MIPS
7484 configurations support dynamic selection of target byte order.
7486 * New DOS host serial code
7488 This version uses DPMI interrupts to handle buffered I/O, so you
7489 no longer need to run asynctsr when debugging boards connected to
7492 *** Changes in GDB-4.13:
7494 * New "complete" command
7496 This lists all the possible completions for the rest of the line, if it
7497 were to be given as a command itself. This is intended for use by emacs.
7499 * Trailing space optional in prompt
7501 "set prompt" no longer adds a space for you after the prompt you set. This
7502 allows you to set a prompt which ends in a space or one that does not.
7504 * Breakpoint hit counts
7506 "info break" now displays a count of the number of times the breakpoint
7507 has been hit. This is especially useful in conjunction with "ignore"; you
7508 can ignore a large number of breakpoint hits, look at the breakpoint info
7509 to see how many times the breakpoint was hit, then run again, ignoring one
7510 less than that number, and this will get you quickly to the last hit of
7513 * Ability to stop printing at NULL character
7515 "set print null-stop" will cause GDB to stop printing the characters of
7516 an array when the first NULL is encountered. This is useful when large
7517 arrays actually contain only short strings.
7519 * Shared library breakpoints
7521 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7522 breakpoints in shared libraries before the executable is run.
7524 * Hardware watchpoints
7526 There is a new hardware breakpoint for the watch command for sparclite
7527 targets. See gdb/sparclite/hw_breakpoint.note.
7529 Hardware watchpoints are also now supported under GNU/Linux.
7533 Annotations have been added. These are for use with graphical interfaces,
7534 and are still experimental. Currently only gdba.el uses these.
7536 * Improved Irix 5 support
7538 GDB now works properly with Irix 5.2.
7540 * Improved HPPA support
7542 GDB now works properly with the latest GCC and GAS.
7544 * New native configurations
7546 Sequent PTX4 i[34]86-sequent-ptx4
7547 HPPA running OSF/1 hppa*-*-osf*
7548 Atari TT running SVR4 m68*-*-sysv4*
7549 RS/6000 LynxOS rs6000-*-lynxos*
7553 OS/9000 i[34]86-*-os9k
7554 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7557 * Hitachi SH7000 and E7000-PC ICE support
7559 There is now support for communicating with the Hitachi E7000-PC ICE.
7560 This is available automatically when GDB is configured for the SH.
7564 As usual, a variety of small fixes and improvements, both generic
7565 and configuration-specific. See the ChangeLog for more detail.
7567 *** Changes in GDB-4.12:
7569 * Irix 5 is now supported
7573 GDB-4.12 on the HPPA has a number of changes which make it unable
7574 to debug the output from the currently released versions of GCC and
7575 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7576 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7577 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7580 *** Changes in GDB-4.11:
7582 * User visible changes:
7586 The "set remotedebug" option is now consistent between the mips remote
7587 target, remote targets using the gdb-specific protocol, UDI (AMD's
7588 debug protocol for the 29k) and the 88k bug monitor. It is now an
7589 integer specifying a debug level (normally 0 or 1, but 2 means more
7590 debugging info for the mips target).
7592 * DEC Alpha native support
7594 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7595 debug info, but GDB works fairly well with the DEC compiler and should
7596 work with a future GCC release. See the README file for a few
7597 Alpha-specific notes.
7599 * Preliminary thread implementation
7601 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7603 * LynxOS native and target support for 386
7605 This release has been hosted on LynxOS 2.2, and also can be configured
7606 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7609 * Improvements in C++ mangling/demangling.
7611 This release has much better g++ debugging, specifically in name
7612 mangling/demangling, virtual function calls, print virtual table,
7613 call methods, ...etc.
7615 *** Changes in GDB-4.10:
7617 * User visible changes:
7619 Remote debugging using the GDB-specific (`target remote') protocol now
7620 supports the `load' command. This is only useful if you have some
7621 other way of getting the stub to the target system, and you can put it
7622 somewhere in memory where it won't get clobbered by the download.
7624 Filename completion now works.
7626 When run under emacs mode, the "info line" command now causes the
7627 arrow to point to the line specified. Also, "info line" prints
7628 addresses in symbolic form (as well as hex).
7630 All vxworks based targets now support a user settable option, called
7631 vxworks-timeout. This option represents the number of seconds gdb
7632 should wait for responses to rpc's. You might want to use this if
7633 your vxworks target is, perhaps, a slow software simulator or happens
7634 to be on the far side of a thin network line.
7638 This release contains support for using a DEC alpha as a GDB host for
7639 cross debugging. Native alpha debugging is not supported yet.
7642 *** Changes in GDB-4.9:
7646 This is the first GDB release which is accompanied by a matching testsuite.
7647 The testsuite requires installation of dejagnu, which should be available
7648 via ftp from most sites that carry GNU software.
7652 'Cfront' style demangling has had its name changed to 'ARM' style, to
7653 emphasize that it was written from the specifications in the C++ Annotated
7654 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7655 disclaimers, it still generated too much confusion with users attempting to
7656 use gdb with AT&T cfront.
7660 GDB now uses a standard remote interface to a simulator library.
7661 So far, the library contains simulators for the Zilog Z8001/2, the
7662 Hitachi H8/300, H8/500 and Super-H.
7664 * New targets supported
7666 H8/300 simulator h8300-hitachi-hms or h8300hms
7667 H8/500 simulator h8500-hitachi-hms or h8500hms
7668 SH simulator sh-hitachi-hms or sh
7669 Z8000 simulator z8k-zilog-none or z8ksim
7670 IDT MIPS board over serial line mips-idt-ecoff
7672 Cross-debugging to GO32 targets is supported. It requires a custom
7673 version of the i386-stub.c module which is integrated with the
7674 GO32 memory extender.
7676 * New remote protocols
7678 MIPS remote debugging protocol.
7680 * New source languages supported
7682 This version includes preliminary support for Chill, a Pascal like language
7683 used by telecommunications companies. Chill support is also being integrated
7684 into the GNU compiler, but we don't know when it will be publically available.
7687 *** Changes in GDB-4.8:
7689 * HP Precision Architecture supported
7691 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7692 version of this support was available as a set of patches from the
7693 University of Utah. GDB does not support debugging of programs
7694 compiled with the HP compiler, because HP will not document their file
7695 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7696 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7698 Many problems in the preliminary version have been fixed.
7700 * Faster and better demangling
7702 We have improved template demangling and fixed numerous bugs in the GNU style
7703 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7704 character types (wchar_t) are now supported. Demangling of each symbol is now
7705 only done once, and is cached when the symbol table for a file is read in.
7706 This results in a small increase in memory usage for C programs, a moderate
7707 increase in memory usage for C++ programs, and a fantastic speedup in
7710 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7711 from the specifications in the Annotated Reference Manual, which AT&T's
7712 compiler does not actually implement.
7714 * G++ multiple inheritance compiler problem
7716 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7717 inheritance lattices was reworked to properly discover ambiguities. We
7718 recently found an example which causes this new algorithm to fail in a
7719 very subtle way, producing bad debug information for those classes.
7720 The file 'gcc.patch' (in this directory) can be applied to gcc to
7721 circumvent the problem. A future GCC release will contain a complete
7724 The previous G++ debug info problem (mentioned below for the gdb-4.7
7725 release) is fixed in gcc version 2.3.2.
7727 * Improved configure script
7729 The `configure' script will now attempt to guess your system type if
7730 you don't supply a host system type. The old scheme of supplying a
7731 host system triplet is preferable over using this. All the magic is
7732 done in the new `config.guess' script. Examine it for details.
7734 We have also brought our configure script much more in line with the FSF's
7735 version. It now supports the --with-xxx options. In particular,
7736 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7737 The resulting GDB will not be able to read arbitrary object file formats --
7738 only the format ``expected'' to be used on the configured target system.
7739 We hope to make this the default in a future release.
7741 * Documentation improvements
7743 There's new internal documentation on how to modify GDB, and how to
7744 produce clean changes to the code. We implore people to read it
7745 before submitting changes.
7747 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7748 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7749 `info' files are also provided. To build `info' files from scratch,
7750 you will need the latest `makeinfo' release, which will be available in
7751 a future texinfo-X.Y release.
7753 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7754 We're not sure exactly which versions have this problem, but it has
7755 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7756 or better. If that isn't possible, there is a patch in
7757 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7758 around this problem.
7762 GDB now supports array constants that can be used in expressions typed in by
7763 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7764 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7767 The new directory `gdb/sparclite' contains a program that demonstrates
7768 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7770 * New native hosts supported
7772 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7773 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7775 * New targets supported
7777 AMD 29k family via UDI a29k-amd-udi or udi29k
7779 * New file formats supported
7781 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7782 HPUX core files, and SCO 3.2v2 core files.
7786 Attaching to processes now works again; thanks for the many bug reports.
7788 We have also stomped on a bunch of core dumps caused by
7789 printf_filtered("%s") problems.
7791 We eliminated a copyright problem on the rpc and ptrace header files
7792 for VxWorks, which was discovered at the last minute during the 4.7
7793 release. You should now be able to build a VxWorks GDB.
7795 You can now interrupt gdb while an attached process is running. This
7796 will cause the attached process to stop, and give control back to GDB.
7798 We fixed problems caused by using too many file descriptors
7799 for reading symbols from object files and libraries. This was
7800 especially a problem for programs that used many (~100) shared
7803 The `step' command now only enters a subroutine if there is line number
7804 information for the subroutine. Otherwise it acts like the `next'
7805 command. Previously, `step' would enter subroutines if there was
7806 any debugging information about the routine. This avoids problems
7807 when using `cc -g1' on MIPS machines.
7809 * Internal improvements
7811 GDB's internal interfaces have been improved to make it easier to support
7812 debugging of multiple languages in the future.
7814 GDB now uses a common structure for symbol information internally.
7815 Minimal symbols (derived from linkage symbols in object files), partial
7816 symbols (from a quick scan of debug information), and full symbols
7817 contain a common subset of information, making it easier to write
7818 shared code that handles any of them.
7820 * New command line options
7822 We now accept --silent as an alias for --quiet.
7826 The memory-mapped-malloc library is now licensed under the GNU Library
7827 General Public License.
7829 *** Changes in GDB-4.7:
7831 * Host/native/target split
7833 GDB has had some major internal surgery to untangle the support for
7834 hosts and remote targets. Now, when you configure GDB for a remote
7835 target, it will no longer load in all of the support for debugging
7836 local programs on the host. When fully completed and tested, this will
7837 ensure that arbitrary host/target combinations are possible.
7839 The primary conceptual shift is to separate the non-portable code in
7840 GDB into three categories. Host specific code is required any time GDB
7841 is compiled on that host, regardless of the target. Target specific
7842 code relates to the peculiarities of the target, but can be compiled on
7843 any host. Native specific code is everything else: it can only be
7844 built when the host and target are the same system. Child process
7845 handling and core file support are two common `native' examples.
7847 GDB's use of /proc for controlling Unix child processes is now cleaner.
7848 It has been split out into a single module under the `target_ops' vector,
7849 plus two native-dependent functions for each system that uses /proc.
7851 * New hosts supported
7853 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7854 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7855 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7857 * New targets supported
7859 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7860 68030 and CPU32 m68030-*-*, m68332-*-*
7862 * New native hosts supported
7864 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7865 (386bsd is not well tested yet)
7866 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7868 * New file formats supported
7870 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7871 supports reading of `a.out.adobe' object files, which are an a.out
7872 format extended with minimal information about multiple sections.
7876 `show copying' is the same as the old `info copying'.
7877 `show warranty' is the same as `info warrantee'.
7878 These were renamed for consistency. The old commands continue to work.
7880 `info handle' is a new alias for `info signals'.
7882 You can now define pre-command hooks, which attach arbitrary command
7883 scripts to any command. The commands in the hook will be executed
7884 prior to the user's command. You can also create a hook which will be
7885 executed whenever the program stops. See gdb.texinfo.
7889 We now deal with Cfront style name mangling, and can even extract type
7890 info from mangled symbols. GDB can automatically figure out which
7891 symbol mangling style your C++ compiler uses.
7893 Calling of methods and virtual functions has been improved as well.
7897 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7898 fixed. This was due to mishandling of the extra N_SO stabs output
7901 We also finally got Ultrix 4.2 running in house, and fixed core file
7902 support, with help from a dozen people on the net.
7904 John M. Farrell discovered that the reason that single-stepping was so
7905 slow on all of the Mips based platforms (primarily SGI and DEC) was
7906 that we were trying to demangle and lookup a symbol used for internal
7907 purposes on every instruction that was being stepped through. Changing
7908 the name of that symbol so that it couldn't be mistaken for a C++
7909 mangled symbol sped things up a great deal.
7911 Rich Pixley sped up symbol lookups in general by getting much smarter
7912 about when C++ symbol mangling is necessary. This should make symbol
7913 completion (TAB on the command line) much faster. It's not as fast as
7914 we'd like, but it's significantly faster than gdb-4.6.
7918 A new user controllable variable 'call_scratch_address' can
7919 specify the location of a scratch area to be used when GDB
7920 calls a function in the target. This is necessary because the
7921 usual method of putting the scratch area on the stack does not work
7922 in systems that have separate instruction and data spaces.
7924 We integrated changes to support the 29k UDI (Universal Debugger
7925 Interface), but discovered at the last minute that we didn't have all
7926 of the appropriate copyright paperwork. We are working with AMD to
7927 resolve this, and hope to have it available soon.
7931 We have sped up the remote serial line protocol, especially for targets
7932 with lots of registers. It now supports a new `expedited status' ('T')
7933 message which can be used in place of the existing 'S' status message.
7934 This allows the remote stub to send only the registers that GDB
7935 needs to make a quick decision about single-stepping or conditional
7936 breakpoints, eliminating the need to fetch the entire register set for
7937 each instruction being stepped through.
7939 The GDB remote serial protocol now implements a write-through cache for
7940 registers, only re-reading the registers if the target has run.
7942 There is also a new remote serial stub for SPARC processors. You can
7943 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7944 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7945 processor with a serial port.
7949 Configure.in files have become much easier to read and modify. A new
7950 `table driven' format makes it more obvious what configurations are
7951 supported, and what files each one uses.
7955 There is a new opcodes library which will eventually contain all of the
7956 disassembly routines and opcode tables. At present, it only contains
7957 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7958 disassembler (binutils/objdump) to share these routines.
7960 The libiberty library is now copylefted under the GNU Library General
7961 Public License. This allows more liberal use, and was done so libg++
7962 can use it. This makes no difference to GDB, since the Library License
7963 grants all the rights from the General Public License.
7967 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7968 reference to the stabs symbol info used by the debugger. It is (as far
7969 as we know) the only published document on this fascinating topic. We
7970 encourage you to read it, compare it to the stabs information on your
7971 system, and send improvements on the document in general (to
7972 bug-gdb@prep.ai.mit.edu).
7974 And, of course, many bugs have been fixed.
7977 *** Changes in GDB-4.6:
7979 * Better support for C++ function names
7981 GDB now accepts as input the "demangled form" of C++ overloaded function
7982 names and member function names, and can do command completion on such names
7983 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7984 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7985 Make use of command completion, it is your friend.
7987 GDB also now accepts a variety of C++ mangled symbol formats. They are
7988 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7989 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7990 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7991 for the list of formats.
7993 * G++ symbol mangling problem
7995 Recent versions of gcc have a bug in how they emit debugging information for
7996 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
7997 directory) can be applied to gcc to fix the problem. Alternatively, if you
7998 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
7999 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8000 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8003 * New 'maintenance' command
8005 All of the commands related to hacking GDB internals have been moved out of
8006 the main command set, and now live behind the 'maintenance' command. This
8007 can also be abbreviated as 'mt'. The following changes were made:
8009 dump-me -> maintenance dump-me
8010 info all-breakpoints -> maintenance info breakpoints
8011 printmsyms -> maintenance print msyms
8012 printobjfiles -> maintenance print objfiles
8013 printpsyms -> maintenance print psymbols
8014 printsyms -> maintenance print symbols
8016 The following commands are new:
8018 maintenance demangle Call internal GDB demangler routine to
8019 demangle a C++ link name and prints the result.
8020 maintenance print type Print a type chain for a given symbol
8022 * Change to .gdbinit file processing
8024 We now read the $HOME/.gdbinit file before processing the argv arguments
8025 (e.g. reading symbol files or core files). This allows global parameters to
8026 be set, which will apply during the symbol reading. The ./.gdbinit is still
8027 read after argv processing.
8029 * New hosts supported
8031 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8033 GNU/Linux support i386-unknown-linux or linux
8035 We are also including code to support the HP/PA running BSD and HPUX. This
8036 is almost guaranteed not to work, as we didn't have time to test or build it
8037 for this release. We are including it so that the more adventurous (or
8038 masochistic) of you can play with it. We also had major problems with the
8039 fact that the compiler that we got from HP doesn't support the -g option.
8042 * New targets supported
8044 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8046 * More smarts about finding #include files
8048 GDB now remembers the compilation directory for all include files, and for
8049 all files from which C is generated (like yacc and lex sources). This
8050 greatly improves GDB's ability to find yacc/lex sources, and include files,
8051 especially if you are debugging your program from a directory different from
8052 the one that contains your sources.
8054 We also fixed a bug which caused difficulty with listing and setting
8055 breakpoints in include files which contain C code. (In the past, you had to
8056 try twice in order to list an include file that you hadn't looked at before.)
8058 * Interesting infernals change
8060 GDB now deals with arbitrary numbers of sections, where the symbols for each
8061 section must be relocated relative to that section's landing place in the
8062 target's address space. This work was needed to support ELF with embedded
8063 stabs used by Solaris-2.0.
8065 * Bug fixes (of course!)
8067 There have been loads of fixes for the following things:
8068 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8069 i960, stabs, DOS(GO32), procfs, etc...
8071 See the ChangeLog for details.
8073 *** Changes in GDB-4.5:
8075 * New machines supported (host and target)
8077 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8079 SGI Irix-4.x mips-sgi-irix4 or iris4
8081 * New malloc package
8083 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8084 Mmalloc is capable of handling multiple heaps of memory. It is also
8085 capable of saving a heap to a file, and then mapping it back in later.
8086 This can be used to greatly speedup the startup of GDB by using a
8087 pre-parsed symbol table which lives in a mmalloc managed heap. For
8088 more details, please read mmalloc/mmalloc.texi.
8092 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8093 'help info proc' for details.
8095 * MIPS ecoff symbol table format
8097 The code that reads MIPS symbol table format is now supported on all hosts.
8098 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8101 * File name changes for MS-DOS
8103 Many files in the config directories have been renamed to make it easier to
8104 support GDB on MS-DOSe systems (which have very restrictive file name
8105 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8106 environment) is close to working but has some remaining problems. Note
8107 that debugging of DOS programs is not supported, due to limitations
8108 in the ``operating system'', but it can be used to host cross-debugging.
8110 * Cross byte order fixes
8112 Many fixes have been made to support cross debugging of Sparc and MIPS
8113 targets from hosts whose byte order differs.
8115 * New -mapped and -readnow options
8117 If memory-mapped files are available on your system through the 'mmap'
8118 system call, you can use the -mapped option on the `file' or
8119 `symbol-file' commands to cause GDB to write the symbols from your
8120 program into a reusable file. If the program you are debugging is
8121 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8122 Future GDB debugging sessions will notice the presence of this file,
8123 and will quickly map in symbol information from it, rather than reading
8124 the symbol table from the executable program. Using the '-mapped'
8125 option in a GDB `file' or `symbol-file' command has the same effect as
8126 starting GDB with the '-mapped' command-line option.
8128 You can cause GDB to read the entire symbol table immediately by using
8129 the '-readnow' option with any of the commands that load symbol table
8130 information (or on the GDB command line). This makes the command
8131 slower, but makes future operations faster.
8133 The -mapped and -readnow options are typically combined in order to
8134 build a `fred.syms' file that contains complete symbol information.
8135 A simple GDB invocation to do nothing but build a `.syms' file for future
8138 gdb -batch -nx -mapped -readnow programname
8140 The `.syms' file is specific to the host machine on which GDB is run.
8141 It holds an exact image of GDB's internal symbol table. It cannot be
8142 shared across multiple host platforms.
8144 * longjmp() handling
8146 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8147 siglongjmp() without losing control. This feature has not yet been ported to
8148 all systems. It currently works on many 386 platforms, all MIPS-based
8149 platforms (SGI, DECstation, etc), and Sun3/4.
8153 Preliminary work has been put in to support the new Solaris OS from Sun. At
8154 this time, it can control and debug processes, but it is not capable of
8159 As always, many many bug fixes. The major areas were with g++, and mipsread.
8160 People using the MIPS-based platforms should experience fewer mysterious
8161 crashes and trashed symbol tables.
8163 *** Changes in GDB-4.4:
8165 * New machines supported (host and target)
8167 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8169 BSD Reno on Vax vax-dec-bsd
8170 Ultrix on Vax vax-dec-ultrix
8172 * New machines supported (target)
8174 AMD 29000 embedded, using EBMON a29k-none-none
8178 GDB continues to improve its handling of C++. `References' work better.
8179 The demangler has also been improved, and now deals with symbols mangled as
8180 per the Annotated C++ Reference Guide.
8182 GDB also now handles `stabs' symbol information embedded in MIPS
8183 `ecoff' symbol tables. Since the ecoff format was not easily
8184 extensible to handle new languages such as C++, this appeared to be a
8185 good way to put C++ debugging info into MIPS binaries. This option
8186 will be supported in the GNU C compiler, version 2, when it is
8189 * New features for SVR4
8191 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8192 shared libraries. Debugging dynamically linked programs should present
8193 only minor differences from debugging statically linked programs.
8195 The `info proc' command will print out information about any process
8196 on an SVR4 system (including the one you are debugging). At the moment,
8197 it prints the address mappings of the process.
8199 If you bring up GDB on another SVR4 system, please send mail to
8200 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8202 * Better dynamic linking support in SunOS
8204 Reading symbols from shared libraries which contain debugging symbols
8205 now works properly. However, there remain issues such as automatic
8206 skipping of `transfer vector' code during function calls, which
8207 make it harder to debug code in a shared library, than to debug the
8208 same code linked statically.
8212 GDB is now using the latest `getopt' routines from the FSF. This
8213 version accepts the -- prefix for options with long names. GDB will
8214 continue to accept the old forms (-option and +option) as well.
8215 Various single letter abbreviations for options have been explicity
8216 added to the option table so that they won't get overshadowed in the
8217 future by other options that begin with the same letter.
8221 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8222 Many assorted bugs have been handled. Many more remain to be handled.
8223 See the various ChangeLog files (primarily in gdb and bfd) for details.
8226 *** Changes in GDB-4.3:
8228 * New machines supported (host and target)
8230 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8231 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8232 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8234 * Almost SCO Unix support
8236 We had hoped to support:
8237 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8238 (except for core file support), but we discovered very late in the release
8239 that it has problems with process groups that render gdb unusable. Sorry
8240 about that. I encourage people to fix it and post the fixes.
8242 * Preliminary ELF and DWARF support
8244 GDB can read ELF object files on System V Release 4, and can handle
8245 debugging records for C, in DWARF format, in ELF files. This support
8246 is preliminary. If you bring up GDB on another SVR4 system, please
8247 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8252 GDB now uses the latest `readline' library. One user-visible change
8253 is that two tabs will list possible command completions, which previously
8254 required typing M-? (meta-question mark, or ESC ?).
8258 The `stepi' bug that many of you noticed has been squashed.
8259 Many bugs in C++ have been handled. Many more remain to be handled.
8260 See the various ChangeLog files (primarily in gdb and bfd) for details.
8262 * State of the MIPS world (in case you wondered):
8264 GDB can understand the symbol tables emitted by the compilers
8265 supplied by most vendors of MIPS-based machines, including DEC. These
8266 symbol tables are in a format that essentially nobody else uses.
8268 Some versions of gcc come with an assembler post-processor called
8269 mips-tfile. This program is required if you want to do source-level
8270 debugging of gcc-compiled programs. I believe FSF does not ship
8271 mips-tfile with gcc version 1, but it will eventually come with gcc
8274 Debugging of g++ output remains a problem. g++ version 1.xx does not
8275 really support it at all. (If you're lucky, you should be able to get
8276 line numbers and stack traces to work, but no parameters or local
8277 variables.) With some work it should be possible to improve the
8280 When gcc version 2 is released, you will have somewhat better luck.
8281 However, even then you will get confusing results for inheritance and
8284 We will eventually provide full debugging of g++ output on
8285 DECstations. This will probably involve some kind of stabs-in-ecoff
8286 encapulation, but the details have not been worked out yet.
8289 *** Changes in GDB-4.2:
8291 * Improved configuration
8293 Only one copy of `configure' exists now, and it is not self-modifying.
8294 Porting BFD is simpler.
8298 The `step' and `next' commands now only stop at the first instruction
8299 of a source line. This prevents the multiple stops that used to occur
8300 in switch statements, for-loops, etc. `Step' continues to stop if a
8301 function that has debugging information is called within the line.
8305 Lots of small bugs fixed. More remain.
8307 * New host supported (not target)
8309 Intel 386 PC clone running Mach i386-none-mach
8312 *** Changes in GDB-4.1:
8314 * Multiple source language support
8316 GDB now has internal scaffolding to handle several source languages.
8317 It determines the type of each source file from its filename extension,
8318 and will switch expression parsing and number formatting to match the
8319 language of the function in the currently selected stack frame.
8320 You can also specifically set the language to be used, with
8321 `set language c' or `set language modula-2'.
8325 GDB now has preliminary support for the GNU Modula-2 compiler,
8326 currently under development at the State University of New York at
8327 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8328 continue through the fall of 1991 and into 1992.
8330 Other Modula-2 compilers are currently not supported, and attempting to
8331 debug programs compiled with them will likely result in an error as the
8332 symbol table is read. Feel free to work on it, though!
8334 There are hooks in GDB for strict type checking and range checking,
8335 in the `Modula-2 philosophy', but they do not currently work.
8339 GDB can now write to executable and core files (e.g. patch
8340 a variable's value). You must turn this switch on, specify
8341 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8342 by assigning a new value to a variable. Modifications take
8345 * Automatic SunOS shared library reading
8347 When you run your program, GDB automatically determines where its
8348 shared libraries (if any) have been loaded, and reads their symbols.
8349 The `share' command is no longer needed. This also works when
8350 examining core files.
8354 You can specify the number of lines that the `list' command shows.
8357 * New machines supported (host and target)
8359 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8360 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8361 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8363 * New hosts supported (not targets)
8365 IBM RT/PC: romp-ibm-aix or rtpc
8367 * New targets supported (not hosts)
8369 AMD 29000 embedded with COFF a29k-none-coff
8370 AMD 29000 embedded with a.out a29k-none-aout
8371 Ultracomputer remote kernel debug a29k-nyu-kern
8373 * New remote interfaces
8379 *** Changes in GDB-4.0:
8383 Wide output is wrapped at good places to make the output more readable.
8385 Gdb now supports cross-debugging from a host machine of one type to a
8386 target machine of another type. Communication with the target system
8387 is over serial lines. The ``target'' command handles connecting to the
8388 remote system; the ``load'' command will download a program into the
8389 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8390 also supports debugging of realtime processes running under VxWorks,
8391 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8392 stub on the target system.
8394 New CPUs supported include the AMD 29000 and Intel 960.
8396 GDB now reads object files and symbol tables via a ``binary file''
8397 library, which allows a single copy of GDB to debug programs of multiple
8398 object file types such as a.out and coff.
8400 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8401 refcard.dvi and refcard.ps are available to format it).
8404 * Control-Variable user interface simplified
8406 All variables that control the operation of the debugger can be set
8407 by the ``set'' command, and displayed by the ``show'' command.
8409 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8410 ``Show prompt'' produces the response:
8411 Gdb's prompt is new-gdb=>.
8413 What follows are the NEW set commands. The command ``help set'' will
8414 print a complete list of old and new set commands. ``help set FOO''
8415 will give a longer description of the variable FOO. ``show'' will show
8416 all of the variable descriptions and their current settings.
8418 confirm on/off: Enables warning questions for operations that are
8419 hard to recover from, e.g. rerunning the program while
8420 it is already running. Default is ON.
8422 editing on/off: Enables EMACS style command line editing
8423 of input. Previous lines can be recalled with
8424 control-P, the current line can be edited with control-B,
8425 you can search for commands with control-R, etc.
8428 history filename NAME: NAME is where the gdb command history
8429 will be stored. The default is .gdb_history,
8430 or the value of the environment variable
8433 history size N: The size, in commands, of the command history. The
8434 default is 256, or the value of the environment variable
8437 history save on/off: If this value is set to ON, the history file will
8438 be saved after exiting gdb. If set to OFF, the
8439 file will not be saved. The default is OFF.
8441 history expansion on/off: If this value is set to ON, then csh-like
8442 history expansion will be performed on
8443 command line input. The default is OFF.
8445 radix N: Sets the default radix for input and output. It can be set
8446 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8447 in the current radix, so "set radix 10" is always a no-op.
8449 height N: This integer value is the number of lines on a page. Default
8450 is 24, the current `stty rows'' setting, or the ``li#''
8451 setting from the termcap entry matching the environment
8454 width N: This integer value is the number of characters on a line.
8455 Default is 80, the current `stty cols'' setting, or the ``co#''
8456 setting from the termcap entry matching the environment
8459 Note: ``set screensize'' is obsolete. Use ``set height'' and
8460 ``set width'' instead.
8462 print address on/off: Print memory addresses in various command displays,
8463 such as stack traces and structure values. Gdb looks
8464 more ``symbolic'' if you turn this off; it looks more
8465 ``machine level'' with it on. Default is ON.
8467 print array on/off: Prettyprint arrays. New convenient format! Default
8470 print demangle on/off: Print C++ symbols in "source" form if on,
8473 print asm-demangle on/off: Same, for assembler level printouts
8476 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8479 * Support for Epoch Environment.
8481 The epoch environment is a version of Emacs v18 with windowing. One
8482 new command, ``inspect'', is identical to ``print'', except that if you
8483 are running in the epoch environment, the value is printed in its own
8487 * Support for Shared Libraries
8489 GDB can now debug programs and core files that use SunOS shared libraries.
8490 Symbols from a shared library cannot be referenced
8491 before the shared library has been linked with the program (this
8492 happens after you type ``run'' and before the function main() is entered).
8493 At any time after this linking (including when examining core files
8494 from dynamically linked programs), gdb reads the symbols from each
8495 shared library when you type the ``sharedlibrary'' command.
8496 It can be abbreviated ``share''.
8498 sharedlibrary REGEXP: Load shared object library symbols for files
8499 matching a unix regular expression. No argument
8500 indicates to load symbols for all shared libraries.
8502 info sharedlibrary: Status of loaded shared libraries.
8507 A watchpoint stops execution of a program whenever the value of an
8508 expression changes. Checking for this slows down execution
8509 tremendously whenever you are in the scope of the expression, but is
8510 quite useful for catching tough ``bit-spreader'' or pointer misuse
8511 problems. Some machines such as the 386 have hardware for doing this
8512 more quickly, and future versions of gdb will use this hardware.
8514 watch EXP: Set a watchpoint (breakpoint) for an expression.
8516 info watchpoints: Information about your watchpoints.
8518 delete N: Deletes watchpoint number N (same as breakpoints).
8519 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8520 enable N: Re-enables watchpoint number N (same as breakpoints).
8523 * C++ multiple inheritance
8525 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8528 * C++ exception handling
8530 Gdb now supports limited C++ exception handling. Besides the existing
8531 ability to breakpoint on an exception handler, gdb can breakpoint on
8532 the raising of an exception (before the stack is peeled back to the
8535 catch FOO: If there is a FOO exception handler in the dynamic scope,
8536 set a breakpoint to catch exceptions which may be raised there.
8537 Multiple exceptions (``catch foo bar baz'') may be caught.
8539 info catch: Lists all exceptions which may be caught in the
8540 current stack frame.
8543 * Minor command changes
8545 The command ``call func (arg, arg, ...)'' now acts like the print
8546 command, except it does not print or save a value if the function's result
8547 is void. This is similar to dbx usage.
8549 The ``up'' and ``down'' commands now always print the frame they end up
8550 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8551 frames without printing.
8553 * New directory command
8555 'dir' now adds directories to the FRONT of the source search path.
8556 The path starts off empty. Source files that contain debug information
8557 about the directory in which they were compiled can be found even
8558 with an empty path; Sun CC and GCC include this information. If GDB can't
8559 find your source file in the current directory, type "dir .".
8561 * Configuring GDB for compilation
8563 For normal use, type ``./configure host''. See README or gdb.texinfo
8566 GDB now handles cross debugging. If you are remotely debugging between
8567 two different machines, type ``./configure host -target=targ''.
8568 Host is the machine where GDB will run; targ is the machine
8569 where the program that you are debugging will run.