1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 12
6 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
7 reading memory tag data for AArch64 MTE from core files generated by
8 the gcore command or the Linux kernel.
10 When a process uses memory-mapped pages protected by memory tags (for
11 example, AArch64 MTE), this additional information will be recorded in
12 the core file in the event of a crash or if GDB generates a core file
13 from the current process state. GDB will show this additional information
14 automatically, or through one of the memory-tag subcommands.
16 * "info breakpoints" now displays enabled breakpoint locations of
17 disabled breakpoints as in the "y-" state. For example:
19 (gdb) info breakpoints
20 Num Type Disp Enb Address What
21 1 breakpoint keep n <MULTIPLE>
22 1.1 y- 0x00000000000011b6 in ...
23 1.2 y- 0x00000000000011c2 in ...
24 1.3 n 0x00000000000011ce in ...
26 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
27 aarch64 architectures.
29 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
31 * Remove support for building against Python 2, it is now only possible to
32 build GDB against Python 3.
34 * DBX mode has been removed.
36 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
37 emit to indicate where a breakpoint should be placed to break in a function
40 * Completion now also offers "NUMBER" for "set" commands that accept
41 a numeric argument and the "unlimited" keyword. For example:
48 (gdb) complete set width
52 * Disassembler styling using libopcodes. GDB now supports
53 disassembler styling using libopcodes. This is only available for
54 some targets (currently x86 and RISC-V). For unsupported targets
55 Python Pygments is still used. For supported targets, libopcodes
56 styling is used by default.
60 maintenance set ignore-prologue-end-flag on|off
61 maintenance show ignore-prologue-end-flag
62 This setting, which is off by default, controls whether GDB ignores the
63 PROLOGUE-END flag from the line-table when skipping prologue. This can be
64 used to force GDB to use prologue analyzers if the line-table is constructed
65 from erroneous debug information.
67 set print nibbles [on|off]
69 This controls whether the 'print/t' command will display binary values
70 in groups of four bits, known as "nibbles". The default is 'off'.
72 maintenance set libopcodes-styling on|off
73 maintenance show libopcodes-styling
74 These can be used to force off libopcodes based styling, the Python
75 Pygments styling will then be used instead.
77 set style disassembler comment
78 show style disassembler comment
79 set style disassembler immediate
80 show style disassembler immediate
81 set style disassembler mnemonic
82 show style disassembler mnemonic
83 set style disassembler register
84 show style disassembler register
85 set style disassembler address
86 show style disassembler address
87 set style disassembler symbol
88 show style disassembler symbol
89 For targets that support libopcodes based styling, these settings
90 control how various aspects of the disassembler output are styled.
91 The 'disassembler address' and 'disassembler symbol' styles are
92 aliases for the 'address' and 'function' styles respectively.
96 maintenance info line-table
97 Add a PROLOGUE-END column to the output which indicates that an
98 entry corresponds to an address where a breakpoint should be placed
99 to be at the first instruction past a function's prologue.
103 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
107 ** GDB will now reformat the doc string for gdb.Command and
108 gdb.Parameter sub-classes to remove unnecessary leading
109 whitespace from each line before using the string as the help
112 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
113 that formats ADDRESS as 'address <symbol+offset>', where symbol is
114 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
115 This is the same format that GDB uses when printing address, symbol,
116 and offset information from the disassembler.
118 ** New function gdb.current_language that returns the name of the
119 current language. Unlike gdb.parameter('language'), this will
122 ** New method gdb.Frame.language that returns the name of the
125 ** New Python API for wrapping GDB's disassembler:
127 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
128 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
129 ARCH is either None or a string containing a bfd architecture
130 name. DISASSEMBLER is registered as a disassembler for
131 architecture ARCH, or for all architectures if ARCH is None.
132 The previous disassembler registered for ARCH is returned, this
133 can be None if no previous disassembler was registered.
135 - gdb.disassembler.Disassembler is the class from which all
136 disassemblers should inherit. Its constructor takes a string,
137 a name for the disassembler, which is currently only used in
138 some debug output. Sub-classes should override the __call__
139 method to perform disassembly, invoking __call__ on this base
140 class will raise an exception.
142 - gdb.disassembler.DisassembleInfo is the class used to describe
143 a single disassembly request from GDB. An instance of this
144 class is passed to the __call__ method of
145 gdb.disassembler.Disassembler and has the following read-only
146 attributes: 'address', and 'architecture', as well as the
147 following method: 'read_memory'.
149 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
150 calls GDB's builtin disassembler on INFO, which is a
151 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
152 optional, its default value is None. If MEMORY_SOURCE is not
153 None then it must be an object that has a 'read_memory' method.
155 - gdb.disassembler.DisassemblerResult is a class that can be used
156 to wrap the result of a call to a Disassembler. It has
157 read-only attributes 'length' and 'string'.
159 ** gdb.Objfile now has an attribute named "is_file". This is True
160 if the objfile comes from a file, and False otherwise.
162 ** New function gdb.print_options that returns a dictionary of the
163 prevailing print options, in the form accepted by
164 gdb.Value.format_string.
166 ** gdb.Value.format_string now uses the format provided by 'print',
167 if it is called during a 'print' or other similar operation.
169 ** gdb.Value.format_string now accepts the 'summary' keyword. This
170 can be used to request a shorter representation of a value, the
171 way that 'set print frame-arguments scalars' does.
173 ** New Python type gdb.BreakpointLocation.
174 The new attribute 'locations' of gdb.Breakpoint returns a list of
175 gdb.BreakpointLocation objects specifying the locations where the
176 breakpoint is inserted into the debuggee.
178 * New features in the GDB remote stub, GDBserver
180 ** GDBserver is now supported on LoongArch GNU/Linux.
182 * LoongArch floating-point support
184 GDB now supports floating-point on LoongArch GNU/Linux.
186 *** Changes in GDB 12
188 * DBX mode is deprecated, and will be removed in GDB 13
190 * GDB 12 is the last release of GDB that will support building against
191 Python 2. From GDB 13, it will only be possible to build GDB itself
192 with Python 3 support.
194 * The disable-randomization setting now works on Windows.
196 * Improved C++ template support
198 GDB now treats functions/types involving C++ templates like it does function
199 overloads. Users may omit parameter lists to set breakpoints on families of
200 template functions, including types/functions composed of multiple template types:
202 (gdb) break template_func(template_1, int)
204 The above will set breakpoints at every function `template_func' where
205 the first function parameter is any template type named `template_1' and
206 the second function parameter is `int'.
208 TAB completion also gains similar improvements.
210 * The FreeBSD native target now supports async mode.
216 Enable or disable multithreaded symbol loading. This is enabled
217 by default, but passing --disable-threading or --enable-threading=no
218 to configure will disable it.
220 Disabling this can cause a performance penalty when there are a lot of
221 symbols to load, but is useful for debugging purposes.
225 maint set backtrace-on-fatal-signal on|off
226 maint show backtrace-on-fatal-signal
227 This setting is 'on' by default. When 'on' GDB will print a limited
228 backtrace to stderr in the situation where GDB terminates with a
229 fatal signal. This only supported on some platforms where the
230 backtrace and backtrace_symbols_fd functions are available.
232 set source open on|off
234 This setting, which is on by default, controls whether GDB will try
235 to open source code files. Switching this off will stop GDB trying
236 to open and read source code files, which can be useful if the files
237 are located over a slow network connection.
241 These are now deprecated aliases for "set max-value-size" and
242 "show max-value-size".
244 task apply [all | TASK-IDS...] [FLAG]... COMMAND
245 Like "thread apply", but applies COMMAND to Ada tasks.
248 Watchpoints can now be restricted to a specific Ada task.
250 maint set internal-error backtrace on|off
251 maint show internal-error backtrace
252 maint set internal-warning backtrace on|off
253 maint show internal-warning backtrace
254 GDB can now print a backtrace of itself when it encounters either an
255 internal-error, or an internal-warning. This is on by default for
256 internal-error and off by default for internal-warning.
259 Deprecated and replaced by "set logging enabled on|off".
261 set logging enabled on|off
263 These commands set or show whether logging is enabled or disabled.
266 You can now exit GDB by using the new command "exit", in addition to
267 the existing "quit" command.
269 set debug threads on|off
271 Print additional debug messages about thread creation and deletion.
273 set debug linux-nat on|off
275 These new commands replaced the old 'set debug lin-lwp' and 'show
276 debug lin-lwp' respectively. Turning this setting on prints debug
277 messages relating to GDB's handling of native Linux inferiors.
279 maint flush source-cache
280 Flush the contents of the source code cache.
282 maint set gnu-source-highlight enabled on|off
283 maint show gnu-source-highlight enabled
284 Whether GDB should use the GNU Source Highlight library for adding
285 styling to source code. When off, the library will not be used, even
286 when available. When GNU Source Highlight isn't used, or can't add
287 styling to a particular source file, then the Python Pygments
288 library will be used instead.
290 set suppress-cli-notifications (on|off)
291 show suppress-cli-notifications
292 This controls whether printing the notifications is suppressed for CLI.
293 CLI notifications occur when you change the selected context
294 (i.e., the current inferior, thread and/or the frame), or when
295 the program being debugged stops (e.g., because of hitting a
296 breakpoint, completing source-stepping, an interrupt, etc.).
298 set style disassembler enabled on|off
299 show style disassembler enabled
300 If GDB is compiled with Python support, and the Python Pygments
301 package is available, then, when this setting is on, disassembler
302 output will have styling applied.
304 set ada source-charset
305 show ada source-charset
306 Set the character set encoding that is assumed for Ada symbols. Valid
307 values for this follow the values that can be passed to the GNAT
308 compiler via the '-gnati' option. The default is ISO-8859-1.
314 These are the new names for the old 'layout', 'focus', 'refresh',
315 and 'winheight' tui commands respectively. The old names still
316 exist as aliases to these new commands.
320 The new command 'tui window width', and the alias 'winwidth' allow
321 the width of a tui window to be adjusted when windows are laid out
326 Control the display of debug output about GDB's tui.
331 Printing of floating-point values with base-modifying formats like
332 /x has been changed to display the underlying bytes of the value in
333 the desired base. This was GDB's documented behavior, but was never
334 implemented correctly.
337 This command can now print a reply, if the reply includes
338 non-printable characters. Any non-printable characters are printed
339 as escaped hex, e.g. \x?? where '??' is replaces with the value of
340 the non-printable character.
343 The clone-inferior command now ensures that the TTY, CMD and ARGS
344 settings are copied from the original inferior to the new one.
345 All modifications to the environment variables done using the 'set
346 environment' or 'unset environment' commands are also copied to the new
349 set debug lin-lwp on|off
351 These commands have been removed from GDB. The new command 'set
352 debug linux-nat' and 'show debug linux-nat' should be used
356 This command now includes information about the width of the tui
357 windows in its output.
363 These commands are now aliases for the 'tui layout', 'tui focus',
364 'tui refresh', and 'tui window height' commands respectively.
366 * GDB's Ada parser now supports an extension for specifying the exact
367 byte contents of a floating-point literal. This can be useful for
368 setting floating-point registers to a precise value without loss of
369 precision. The syntax is an extension of the based literal syntax.
370 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
371 of the floating-point type, and the "f" is the marker for floating
376 ** The '-add-inferior' with no option flags now inherits the
377 connection of the current inferior, this restores the behaviour of
378 GDB as it was prior to GDB 10.
380 ** The '-add-inferior' command now accepts a '--no-connection'
381 option, which causes the new inferior to start without a
386 GNU/Linux/LoongArch loongarch*-*-linux*
394 ** New function gdb.add_history(), which takes a gdb.Value object
395 and adds the value it represents to GDB's history list. An
396 integer, the index of the new item in the history list, is
399 ** New function gdb.history_count(), which returns the number of
400 values in GDB's value history.
402 ** New gdb.events.gdb_exiting event. This event is called with a
403 gdb.GdbExitingEvent object which has the read-only attribute
404 'exit_code', which contains the value of the GDB exit code. This
405 event is triggered once GDB decides it is going to exit, but
406 before GDB starts to clean up its internal state.
408 ** New function gdb.architecture_names(), which returns a list
409 containing all of the possible Architecture.name() values. Each
412 ** New function gdb.Architecture.integer_type(), which returns an
413 integer type given a size and a signed-ness.
415 ** New gdb.TargetConnection object type that represents a connection
416 (as displayed by the 'info connections' command). A sub-class,
417 gdb.RemoteTargetConnection, is used to represent 'remote' and
418 'extended-remote' connections.
420 ** The gdb.Inferior type now has a 'connection' property which is an
421 instance of gdb.TargetConnection, the connection used by this
422 inferior. This can be None if the inferior has no connection.
424 ** New 'gdb.events.connection_removed' event registry, which emits a
425 'gdb.ConnectionEvent' when a connection is removed from GDB.
426 This event has a 'connection' property, a gdb.TargetConnection
427 object for the connection being removed.
429 ** New gdb.connections() function that returns a list of all
430 currently active connections.
432 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
433 is equivalent to the existing 'maint packet' CLI command; it
434 allows a user specified packet to be sent to the remote target.
436 ** New function gdb.host_charset(), returns a string, which is the
437 name of the current host charset.
439 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
442 ** New gdb.with_parameter(NAME, VALUE). This returns a context
443 manager that temporarily sets the gdb parameter NAME to VALUE,
444 then resets it when the context is exited.
446 ** The gdb.Value.format_string method now takes a 'styling'
447 argument, which is a boolean. When true, the returned string can
448 include escape sequences to apply styling. The styling will only
449 be present if styling is otherwise turned on in GDB (see 'help
450 set styling'). When false, which is the default if the argument
451 is not given, then no styling is applied to the returned string.
453 ** New read-only attribute gdb.InferiorThread.details, which is
454 either a string, containing additional, target specific thread
455 state information, or None, if there is no such additional
458 ** New read-only attribute gdb.Type.is_scalar, which is True for
459 scalar types, and False for all other types.
461 ** New read-only attribute gdb.Type.is_signed. This attribute
462 should only be read when Type.is_scalar is True, and will be True
463 for signed types, and False for all other types. Attempting to
464 read this attribute for non-scalar types will raise a ValueError.
466 ** It is now possible to add GDB/MI commands implemented in Python.
468 * New features in the GDB remote stub, GDBserver
470 ** GDBserver is now supported on OpenRISC GNU/Linux.
472 * New native configurations
474 GNU/Linux/OpenRISC or1k*-*-linux*
476 *** Changes in GDB 11
478 * The 'set disassembler-options' command now supports specifying options
481 * GDB now supports general memory tagging functionality if the underlying
482 architecture supports the proper primitives and hooks. Currently this is
483 enabled only for AArch64 MTE.
487 - Additional information when the inferior crashes with a SIGSEGV caused by
488 a memory tag violation.
490 - A new modifier 'm' for the "x" command, which displays allocation tags for a
491 particular memory range.
493 - Display of memory tag mismatches by "print", for addresses and
494 pointers, if memory tagging is supported by the architecture.
496 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
501 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
503 The MI -break-insert and -dprintf-insert commands now support a
504 new "--qualified" option that makes GDB interpret a specified
505 function name as a complete fully-qualified name. This is the
506 equivalent of the CLI's "break -qualified" and "dprintf
509 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
511 The MI -break-insert and -dprintf-insert commands now support a
512 '--force-condition' flag to forcibly define a condition even when
513 the condition is invalid at all locations of the breakpoint. This
514 is equivalent to the '-force-condition' flag of the CLI's "break"
517 ** '-break-condition --force'
519 The MI -break-condition command now supports a '--force' flag to
520 forcibly define a condition even when the condition is invalid at
521 all locations of the selected breakpoint. This is equivalent to
522 the '-force' flag of the CLI's "cond" command.
524 ** '-file-list-exec-source-files [--group-by-objfile]
525 [--basename | --dirname]
528 The existing -file-list-exec-source-files command now takes an
529 optional REGEXP which is used to filter the source files that are
530 included in the results.
532 By default REGEXP is matched against the full filename of the
533 source file. When one of --basename or --dirname is given then
534 REGEXP is only matched against the specified part of the full
537 When the optional --group-by-objfile flag is used the output
538 format is changed, the results are now a list of object files
539 (executable and libraries) with the source files that are
540 associated with each object file.
542 The results from -file-list-exec-source-files now include a
543 'debug-fully-read' field which takes the value 'true' or 'false'.
544 A 'true' value indicates the source file is from a compilation
545 unit that has had its debug information fully read in by GDB, a
546 value of 'false' indicates GDB has only performed a partial scan
547 of the debug information so far.
549 * GDB now supports core file debugging for x86_64 Cygwin programs.
551 * GDB will now look for the .gdbinit file in a config directory before
552 looking for ~/.gdbinit. The file is searched for in the following
553 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
554 $HOME/.gdbinit. On Apple hosts the search order is instead:
555 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
557 * GDB now supports fixed point types which are described in DWARF
558 as base types with a fixed-point encoding. Additionally, support
559 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
562 For Ada, this allows support for fixed point types without requiring
563 the use of the GNAT encoding (based on information added to the type's
564 name following a GNAT-specific format).
566 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
567 or ~/.gdbearlyinit if these files are present. These files are
568 processed earlier than any of the other initialization files and
569 can affect parts of GDB's startup that previously had already been
570 completed before the initialization files were read, for example
571 styling of the initial GDB greeting.
573 * GDB now has two new options "--early-init-command" and
574 "--early-init-eval-command" with corresponding short options "-eix"
575 and "-eiex" that allow options (that would normally appear in a
576 gdbearlyinit file) to be passed on the command line.
578 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
579 now understood by GDB, and can be used to describe the vector
580 registers of a target. The precise requirements of this register
581 feature are documented in the GDB manual.
583 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
584 supported by GDB and describes a new VPR register from the ARM MVE
585 (Helium) extension. See the GDB manual for more information.
589 ** TUI windows now support mouse actions. The mouse wheel scrolls
590 the appropriate window.
592 ** Key combinations that do not have a specific action on the
593 focused window are passed to GDB. For example, you now can use
594 Ctrl-Left/Ctrl-Right to move between words in the command window
595 regardless of which window is in focus. Previously you would
596 need to focus on the command window for such key combinations to
602 show debug event-loop
603 Control the display of debug output about GDB's event loop.
605 set print memory-tag-violations
606 show print memory-tag-violations
607 Control whether to display additional information about memory tag violations
608 when printing pointers and addresses. Architecture support for memory
609 tagging is required for this option to have an effect.
611 maintenance flush symbol-cache
612 maintenance flush register-cache
613 These new commands are equivalent to the already existing commands
614 'maintenance flush-symbol-cache' and 'flushregs' respectively.
616 maintenance flush dcache
617 A new command to flush the dcache.
619 maintenance info target-sections
620 Print GDB's internal target sections table.
623 Print the JIT code objects in the inferior known to GDB.
625 memory-tag show-logical-tag POINTER
626 Print the logical tag for POINTER.
627 memory-tag with-logical-tag POINTER TAG
628 Print POINTER with logical tag TAG.
629 memory-tag show-allocation-tag ADDRESS
630 Print the allocation tag for ADDRESS.
631 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
632 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
633 memory-tag check POINTER
634 Validate that POINTER's logical tag matches the allocation tag.
636 set startup-quietly on|off
638 When 'on', this causes GDB to act as if "-silent" were passed on the
639 command line. This command needs to be added to an early
640 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
643 set print type hex on|off
645 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
646 and offsets of struct members. When 'off', decimal notation is used.
648 set python ignore-environment on|off
649 show python ignore-environment
650 When 'on', this causes GDB's builtin Python to ignore any
651 environment variables that would otherwise affect how Python
652 behaves. This command needs to be added to an early initialization
653 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
655 set python dont-write-bytecode auto|on|off
656 show python dont-write-bytecode
657 When 'on', this causes GDB's builtin Python to not write any
658 byte-code (.pyc files) to disk. This command needs to be added to
659 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
660 order to affect GDB. When 'off' byte-code will always be written.
661 When set to 'auto' (the default) Python will check the
662 PYTHONDONTWRITEBYTECODE environment variable.
666 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
667 [-force-condition] [if CONDITION]
668 This command would previously refuse setting a breakpoint if the
669 CONDITION expression is invalid at a location. It now accepts and
670 defines the breakpoint if there is at least one location at which
671 the CONDITION is valid. The locations for which the CONDITION is
672 invalid, are automatically disabled. If CONDITION is invalid at all
673 of the locations, setting the breakpoint is still rejected. However,
674 the '-force-condition' flag can be used in this case for forcing GDB to
675 define the breakpoint, making all the current locations automatically
676 disabled. This may be useful if the user knows the condition will
677 become meaningful at a future location, e.g. due to a shared library
680 condition [-force] N COND
681 The behavior of this command is changed the same way for the 'break'
682 command as explained above. The '-force' flag can be used to force
683 GDB into defining the condition even when COND is invalid for all the
684 current locations of breakpoint N.
687 maintenance flush-symbol-cache
688 These commands are deprecated in favor of the new commands
689 'maintenance flush register-cache' and 'maintenance flush
690 symbol-cache' respectively.
692 set style version foreground COLOR
693 set style version background COLOR
694 set style version intensity VALUE
695 Control the styling of GDB's version number text.
698 When the ID parameter is omitted, then this command prints information
699 about the current inferior. When the ID parameter is present, the
700 behavior of the command is unchanged and have the inferior ID become
701 the current inferior.
703 maintenance info sections
704 The ALLOBJ keyword has been replaced with an -all-objects command
705 line flag. It is now possible to filter which sections are printed
706 even when -all-objects is passed.
708 ptype[/FLAGS] TYPE | EXPRESSION
709 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
710 notation is used when printing sizes and offsets of struct members.
711 When '/d' is set, decimal notation is used when printing sizes and
712 offsets of struct members. Default behavior is given by 'show print
716 The info sources command output has been restructured. The results
717 are now based around a list of objfiles (executable and libraries),
718 and for each objfile the source files that are part of that objfile
721 * Removed targets and native configurations
723 ARM Symbian arm*-*-symbianelf*
728 Request the remote to send allocation tags for a particular memory range.
730 Request the remote to store the specified allocation tags to the requested
735 ** Improved support for rvalue reference values:
736 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
737 value-referenced-value procedure now handles rvalue reference
740 ** New procedures for obtaining value variants:
741 value-reference-value, value-rvalue-reference-value and
744 ** Temporary breakpoints can now be created with make-breakpoint and
745 tested for using breakpoint-temporary?.
749 ** Inferior objects now contain a read-only 'connection_num' attribute that
750 gives the connection number as seen in 'info connections' and
753 ** New method gdb.Frame.level() which returns the stack level of the
756 ** New method gdb.PendingFrame.level() which returns the stack level
759 ** When hitting a catchpoint, the Python API will now emit a
760 gdb.BreakpointEvent rather than a gdb.StopEvent. The
761 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
763 ** Python TUI windows can now receive mouse click events. If the
764 Window object implements the click method, it is called for each
765 mouse click event in this window.
767 *** Changes in GDB 10
769 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
770 and "org.gnu.gdb.arc.aux". The old names are still supported but
771 must be considered obsolete. They will be deprecated after some
774 * Help and apropos commands will now show the documentation of a
775 command only once, even if that command has one or more aliases.
776 These commands now show the command name, then all of its aliases,
777 and finally the description of the command.
779 * 'help aliases' now shows only the user defined aliases. GDB predefined
780 aliases are shown together with their aliased command.
782 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
783 debugging information as well as source code.
785 When built with debuginfod, GDB can automatically query debuginfod
786 servers for the separate debug files and source code of the executable
789 To build GDB with debuginfod, pass --with-debuginfod to configure (this
790 requires libdebuginfod, the debuginfod client library).
792 debuginfod is distributed with elfutils, starting with version 0.178.
794 You can get the latest version from https://sourceware.org/elfutils.
796 * Multi-target debugging support
798 GDB now supports debugging multiple target connections
799 simultaneously. For example, you can now have each inferior
800 connected to different remote servers running in different machines,
801 or have one inferior debugging a local native process, an inferior
802 debugging a core dump, etc.
804 This support is experimental and comes with some limitations -- you
805 can only resume multiple targets simultaneously if all targets
806 support non-stop mode, and all remote stubs or servers must support
807 the same set of remote protocol features exactly. See also "info
808 connections" and "add-inferior -no-connection" below, and "maint set
809 target-non-stop" in the user manual.
811 * New features in the GDB remote stub, GDBserver
813 ** GDBserver is now supported on ARC GNU/Linux.
815 ** GDBserver is now supported on RISC-V GNU/Linux.
817 ** GDBserver no longer supports these host triplets:
828 i[34567]86-*-mingw32ce*
830 * Debugging MS-Windows processes now sets $_exitsignal when the
831 inferior is terminated by a signal, instead of setting $_exitcode.
833 * Multithreaded symbol loading has now been enabled by default on systems
834 that support it (see entry for GDB 9, below), providing faster
835 performance for programs with many symbols.
837 * The $_siginfo convenience variable now also works on Windows targets,
838 and will display the EXCEPTION_RECORD of the last handled exception.
840 * TUI windows can now be arranged horizontally.
842 * The command history filename can now be set to the empty string
843 either using 'set history filename' or by setting 'GDBHISTFILE=' in
844 the environment. The effect of setting this filename to the empty
845 string is that GDB will not try to load any previous command
848 * On Windows targets, it is now possible to debug 32-bit programs with a
853 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
854 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
855 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
856 running process, this new option indicates whether to detect
857 a mismatch between the current executable file loaded by GDB and the
858 executable file used to start the process. If 'ask', the default,
859 display a warning and ask the user whether to load the process
860 executable file; if 'warn', just display a warning; if 'off', don't
861 attempt to detect a mismatch.
863 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
864 Define a new TUI layout, specifying its name and the windows that
867 maintenance print xml-tdesc [FILE]
868 Prints the current target description as an XML document. If the
869 optional FILE is provided (which is an XML target description) then
870 the target description is read from FILE into GDB, and then
873 maintenance print core-file-backed-mappings
874 Prints file-backed mappings loaded from a core file's note section.
875 Output is expected to be similar to that of "info proc mappings".
877 set debug fortran-array-slicing on|off
878 show debug fortran-array-slicing
879 Print debugging when taking slices of Fortran arrays.
881 set fortran repack-array-slices on|off
882 show fortran repack-array-slices
883 When taking slices from Fortran arrays and strings, if the slice is
884 non-contiguous within the original value then, when this option is
885 on, the new value will be repacked into a single contiguous value.
886 When this option is off, then the value returned will consist of a
887 descriptor that describes the slice within the memory of the
888 original parent value.
892 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
893 The alias command can now specify default args for an alias.
894 GDB automatically prepends the alias default args to the argument list
895 provided explicitly by the user.
896 For example, to have a backtrace with full details, you can define
898 'alias bt_ALL = backtrace -entry-values both -frame-arg all
899 -past-main -past-entry -full'.
900 Alias default arguments can also use a set of nested 'with' commands,
901 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
902 defines the alias pp10 that will pretty print a maximum of 10 elements
903 of the given expression (if the expression is an array).
907 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
913 ** gdb.register_window_type can be used to implement new TUI windows
916 ** Dynamic types can now be queried. gdb.Type has a new attribute,
917 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
918 field of a dynamic type may have None for its "bitpos" attribute
921 ** Commands written in Python can be in the "TUI" help class by
922 registering with the new constant gdb.COMMAND_TUI.
924 ** New method gdb.PendingFrame.architecture () to retrieve the
925 architecture of the pending frame.
927 ** New gdb.Architecture.registers method that returns a
928 gdb.RegisterDescriptorIterator object, an iterator that returns
929 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
930 way to query the registers available for an architecture.
932 ** New gdb.Architecture.register_groups method that returns a
933 gdb.RegisterGroupIterator object, an iterator that returns
934 gdb.RegisterGroup objects. The new RegisterGroup is a way to
935 discover the available register groups.
939 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
941 ** Procedures 'memory-port-read-buffer-size',
942 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
943 and 'set-memory-port-write-buffer-size!' are deprecated. When
944 using Guile 2.2 and later, users who need to control the size of
945 a memory port's internal buffer can use the 'setvbuf' procedure.
949 * 'thread-exited' event is now available in the annotations interface.
951 * New built-in convenience variables $_gdb_major and $_gdb_minor
952 provide the GDB version. They are handy for conditionally using
953 features available only in or since specific GDB versions, in
954 scripts that should work error-free with many different versions,
955 such as in system-wide init files.
957 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
958 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
959 of the GDB settings and the GDB maintenance settings. They are handy
960 for changing the logic of user defined commands depending on the
961 current GDB settings.
963 * GDB now supports Thread Local Storage (TLS) variables on several
964 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
965 architectures require kernel changes. TLS is not yet supported for
966 amd64 and i386 process core dumps.
968 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
969 addresses that required unmasking are shown in the backtrace with the
972 * Two new convenience functions $_cimag and $_creal that extract the
973 imaginary and real parts respectively from complex numbers.
975 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
976 provide the exitcode or exit status of the shell commands launched by
977 GDB commands such as "shell", "pipe" and "make".
979 * The command define-prefix can now define user defined prefix commands.
980 User defined commands can now be defined using these user defined prefix
983 * Command names can now use the . character.
985 * The RX port now supports XML target descriptions.
987 * GDB now shows the Ada task names at more places, e.g. in task switching
990 * GDB can now be compiled with Python 3 on Windows.
992 * New convenience variable $_ada_exception holds the address of the
993 Ada exception being thrown. This is set by Ada-related catchpoints.
995 * GDB can now place breakpoints on nested functions and subroutines in
996 Fortran code. The '::' operator can be used between parent and
997 child scopes when placing breakpoints, for example:
999 (gdb) break outer_function::inner_function
1001 The 'outer_function::' prefix is only needed if 'inner_function' is
1002 not visible in the current scope.
1004 * In addition to the system-wide gdbinit file, if configured with
1005 --with-system-gdbinit-dir, GDB will now also load files in that directory
1006 as system gdbinit files, unless the -nx or -n flag is provided. Files
1007 with extensions .gdb, .py and .scm are supported as long as GDB was
1008 compiled with support for that language.
1010 * GDB now supports multithreaded symbol loading for higher performance.
1011 This feature is still in testing, so it is disabled by default. You
1012 can turn it on using 'maint set worker-threads unlimited'.
1016 ** The gdb.Value type has a new method 'format_string' which returns a
1017 string representing the value. The formatting is controlled by the
1018 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1019 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1020 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1022 ** gdb.Type has a new property 'objfile' which returns the objfile the
1023 type was defined in.
1025 ** The frame information printed by the python frame filtering code
1026 is now consistent with what the 'backtrace' command prints when
1027 there are no filters, or when the 'backtrace' '-no-filters' option
1030 ** The new function gdb.lookup_static_symbol can be used to look up
1031 symbols with static linkage.
1033 ** The new function gdb.lookup_static_symbols can be used to look up
1034 all static symbols with static linkage.
1036 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1037 'lookup_static_symbol' to lookup a symbol from this objfile only.
1039 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1040 this block (e.g. block['local_variable']).
1044 | [COMMAND] | SHELL_COMMAND
1045 | -d DELIM COMMAND DELIM SHELL_COMMAND
1046 pipe [COMMAND] | SHELL_COMMAND
1047 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1048 Executes COMMAND and sends its output to SHELL_COMMAND.
1049 With no COMMAND, repeat the last executed command
1050 and send its output to SHELL_COMMAND.
1052 define-prefix COMMAND
1053 Define or mark a command as a user-defined prefix command.
1055 with SETTING [VALUE] [-- COMMAND]
1056 w SETTING [VALUE] [-- COMMAND]
1057 Temporarily set SETTING, run COMMAND, and restore SETTING.
1058 Usage: with SETTING -- COMMAND
1059 With no COMMAND, repeats the last executed command.
1060 SETTING is any GDB setting you can change with the "set"
1061 subcommands. For example, 'with language c -- print someobj'
1062 temporarily switches to the C language in order to print someobj.
1063 Settings can be combined: 'w lang c -- w print elements unlimited --
1064 usercmd' switches to the C language and runs usercmd with no limit
1065 of array elements to print.
1067 maint with SETTING [VALUE] [-- COMMAND]
1068 Like "with", but works with "maintenance set" settings.
1070 set may-call-functions [on|off]
1071 show may-call-functions
1072 This controls whether GDB will attempt to call functions in
1073 the program, such as with expressions in the print command. It
1074 defaults to on. Calling functions in the program being debugged
1075 can have undesired side effects. It is now possible to forbid
1076 such function calls. If function calls are forbidden, GDB will throw
1077 an error when a command (such as print expression) calls a function
1080 set print finish [on|off]
1082 This controls whether the `finish' command will display the value
1083 that is returned by the current function. When `off', the value is
1084 still entered into the value history, but it is not printed. The
1088 show print max-depth
1089 Allows deeply nested structures to be simplified when printing by
1090 replacing deeply nested parts (beyond the max-depth) with ellipses.
1091 The default max-depth is 20, but this can be set to unlimited to get
1092 the old behavior back.
1094 set print raw-values [on|off]
1095 show print raw-values
1096 By default, GDB applies the enabled pretty printers when printing a
1097 value. This allows to ignore the enabled pretty printers for a series
1098 of commands. The default is 'off'.
1100 set logging debugredirect [on|off]
1101 By default, GDB debug output will go to both the terminal and the logfile.
1102 Set if you want debug output to go only to the log file.
1104 set style title foreground COLOR
1105 set style title background COLOR
1106 set style title intensity VALUE
1107 Control the styling of titles.
1109 set style highlight foreground COLOR
1110 set style highlight background COLOR
1111 set style highlight intensity VALUE
1112 Control the styling of highlightings.
1114 maint set worker-threads
1115 maint show worker-threads
1116 Control the number of worker threads that can be used by GDB. The
1117 default is 0. "unlimited" lets GDB choose a number that is
1118 reasonable. Currently worker threads are only used when demangling
1119 the names of linker symbols.
1121 set style tui-border foreground COLOR
1122 set style tui-border background COLOR
1123 Control the styling of TUI borders.
1125 set style tui-active-border foreground COLOR
1126 set style tui-active-border background COLOR
1127 Control the styling of the active TUI border.
1129 maint set test-settings KIND
1130 maint show test-settings KIND
1131 A set of commands used by the testsuite for exercising the settings
1134 maint set tui-resize-message [on|off]
1135 maint show tui-resize-message
1136 Control whether GDB prints a message each time the terminal is
1137 resized when in TUI mode. This is primarily useful for testing the
1140 set print frame-info [short-location|location|location-and-address
1141 |source-and-location|source-line|auto]
1142 show print frame-info
1143 This controls what frame information is printed by the commands printing
1144 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1145 'frame', 'stepi'. The python frame filtering also respect this setting.
1146 The 'backtrace' '-frame-info' option can override this global setting.
1148 set tui compact-source
1149 show tui compact-source
1151 Enable the "compact" display mode for the TUI source window. The
1152 compact display uses only as much space as is needed for the line
1153 numbers in the current file, and only a single space to separate the
1154 line numbers from the source.
1156 info modules [-q] [REGEXP]
1157 Return a list of Fortran modules matching REGEXP, or all modules if
1160 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1161 Return a list of functions within all modules, grouped by module.
1162 The list of functions can be restricted with the optional regular
1163 expressions. MODULE_REGEXP matches against the module name,
1164 TYPE_REGEXP matches against the function type signature, and REGEXP
1165 matches against the function name.
1167 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1168 Return a list of variables within all modules, grouped by module.
1169 The list of variables can be restricted with the optional regular
1170 expressions. MODULE_REGEXP matches against the module name,
1171 TYPE_REGEXP matches against the variable type, and REGEXP matches
1172 against the variable name.
1174 set debug remote-packet-max-chars
1175 show debug remote-packet-max-chars
1176 Controls the number of characters to output in a remote packet when using
1178 The default is 512 bytes.
1181 Lists the target connections currently in use.
1186 The "help" command uses the title style to enhance the
1187 readibility of its output by styling the classes and
1191 Similarly to "help", the "apropos" command also uses the
1192 title style for the command names. "apropos" accepts now
1193 a flag "-v" (verbose) to show the full documentation
1194 of matching commands and to use the highlight style to mark
1195 the documentation parts matching REGEXP.
1199 The GDB printf and eval commands can now print C-style and Ada-style
1200 string convenience variables without calling functions in the program.
1201 This allows to do formatted printing of strings without having
1202 a running inferior, or when debugging a core dump.
1204 info sources [-dirname | -basename] [--] [REGEXP]
1205 This command has now optional arguments to only print the files
1206 whose names match REGEXP. The arguments -dirname and -basename
1207 allow to restrict matching respectively to the dirname and basename
1211 The "show style" and its subcommands are now styling
1212 a style name in their output using its own style, to help
1213 the user visualize the different styles.
1215 set print frame-arguments
1216 The new value 'presence' indicates to only indicate the presence of
1217 arguments using ..., instead of printing argument names and values.
1219 set print raw-frame-arguments
1220 show print raw-frame-arguments
1222 These commands replace the similarly-named "set/show print raw
1223 frame-arguments" commands (now with a dash instead of a space). The
1224 old commands are now deprecated and may be removed in a future
1227 add-inferior [-no-connection]
1228 The add-inferior command now supports a "-no-connection" flag that
1229 makes the new inferior start with no target connection associated.
1230 By default, the new inferior inherits the target connection of the
1231 current inferior. See also "info connections".
1234 This command's output now includes a new "Connection" column
1235 indicating which target connection an inferior is bound to. See
1236 "info connections" above.
1238 maint test-options require-delimiter
1239 maint test-options unknown-is-error
1240 maint test-options unknown-is-operand
1241 maint show test-options-completion-result
1242 Commands used by the testsuite to validate the command options
1245 focus, winheight, +, -, >, <
1246 These commands are now case-sensitive.
1248 * New command options, command completion
1250 GDB now has a standard infrastructure to support dash-style command
1251 options ('-OPT'). One benefit is that commands that use it can
1252 easily support completion of command line arguments. Try "CMD
1253 -[TAB]" or "help CMD" to find options supported by a command. Over
1254 time, we intend to migrate most commands to this infrastructure. A
1255 number of commands got support for new command options in this
1258 ** The "print" and "compile print" commands now support a number of
1259 options that allow overriding relevant global print settings as
1260 set by "set print" subcommands:
1264 -array-indexes [on|off]
1265 -elements NUMBER|unlimited
1269 -raw-values [on|off]
1270 -repeats NUMBER|unlimited
1271 -static-members [on|off]
1276 Note that because the "print"/"compile print" commands accept
1277 arbitrary expressions which may look like options (including
1278 abbreviations), if you specify any command option, then you must
1279 use a double dash ("--") to mark the end of argument processing.
1281 ** The "backtrace" command now supports a number of options that
1282 allow overriding relevant global print settings as set by "set
1283 backtrace" and "set print" subcommands:
1285 -entry-values no|only|preferred|if-needed|both|compact|default
1286 -frame-arguments all|scalars|none
1287 -raw-frame-arguments [on|off]
1288 -frame-info auto|source-line|location|source-and-location
1289 |location-and-address|short-location
1291 -past-entry [on|off]
1293 In addition, the full/no-filters/hide qualifiers are now also
1294 exposed as command options too:
1300 ** The "frame apply", "tfaas" and "faas" commands similarly now
1301 support the following options:
1304 -past-entry [on|off]
1306 ** The new "info sources" options -dirname and -basename options
1307 are using the standard '-OPT' infrastructure.
1309 All options above can also be abbreviated. The argument of boolean
1310 (on/off) options can be 0/1 too, and also the argument is assumed
1311 "on" if omitted. This allows writing compact command invocations,
1314 (gdb) p -ra -p -o 0 -- *myptr
1316 The above is equivalent to:
1318 (gdb) print -raw-values -pretty -object off -- *myptr
1320 ** The "info types" command now supports the '-q' flag to disable
1321 printing of some header information in a similar fashion to "info
1322 variables" and "info functions".
1324 ** The "info variables", "info functions", and "whereis" commands
1325 now take a '-n' flag that excludes non-debug symbols (symbols
1326 from the symbol table, not from the debug info such as DWARF)
1329 * Completion improvements
1331 ** GDB can now complete the options of the "thread apply all" and
1332 "taas" commands, and their "-ascending" option can now be
1335 ** GDB can now complete the options of the "info threads", "info
1336 functions", "info variables", "info locals", and "info args"
1339 ** GDB can now complete the options of the "compile file" and
1340 "compile code" commands. The "compile file" command now
1341 completes on filenames.
1343 ** GDB can now complete the backtrace command's
1344 "full/no-filters/hide" qualifiers.
1346 * In settings, you can now abbreviate "unlimited".
1348 E.g., "set print elements u" is now equivalent to "set print
1349 elements unlimited".
1354 This lists all the possible completions for the rest of the line, if it
1355 were to be given as a command itself. This is intended for use by MI
1356 frontends in cases when separate CLI and MI channels cannot be used.
1358 -catch-throw, -catch-rethrow, and -catch-catch
1359 These can be used to catch C++ exceptions in a similar fashion to
1360 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1362 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1363 These commands are the MI equivalent of the CLI commands 'info
1364 functions', 'info types', and 'info variables' respectively.
1366 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1369 -symbol-info-module-functions and -symbol-info-module-variables.
1370 These commands are the MI equivalent of the CLI commands 'info
1371 module functions' and 'info module variables'.
1375 ** The default version of the MI interpreter is now 3 (-i=mi3).
1377 ** The output of information about multi-location breakpoints (which is
1378 syntactically incorrect in MI 2) has changed in MI 3. This affects
1379 the following commands and events:
1383 - =breakpoint-created
1384 - =breakpoint-modified
1386 The -fix-multi-location-breakpoint-output command can be used to enable
1387 this behavior with previous MI versions.
1389 ** Backtraces and frames include a new optional field addr_flags which is
1390 given after the addr field. On AArch64 this contains PAC if the address
1391 has been masked in the frame. On all other targets the field is not
1396 The testsuite now creates the files gdb.cmd (containing the arguments
1397 used to launch GDB) and gdb.in (containing all the commands sent to
1398 GDB) in the output directory for each test script. Multiple invocations
1399 are appended with .1, .2, .3 etc.
1401 * Building GDB and GDBserver now requires GNU make >= 3.82.
1403 Using another implementation of the make program or an earlier version of
1404 GNU make to build GDB or GDBserver is not supported.
1406 * Building GDB now requires GNU readline >= 7.0.
1408 GDB now bundles GNU readline 8.0, but if you choose to use
1409 --with-system-readline, only readline >= 7.0 can be used.
1411 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1412 from .inputrc to bind keys in this keymap. This feature is only
1413 available when gdb is built against GNU readline 8.0 or later.
1415 * Removed targets and native configurations
1417 GDB no longer supports debugging the Cell Broadband Engine. This includes
1418 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1419 of Cell/B.E. applications that use both the PPU and SPU architectures.
1425 * Removed targets and native configurations
1427 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1428 sparc*-*-solaris2.10
1430 *** Changes in GDB 8.3
1432 * GDB and GDBserver now support access to additional registers on
1433 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1436 * GDB now has experimental support for the compilation and injection of
1437 C++ source code into the inferior. This beta release does not include
1438 support for several language features, such as templates, constructors,
1441 This feature requires GCC 7.1 or higher built with libcp1.so
1444 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1445 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1446 'ADDRESS:PORT' method.
1448 * DWARF index cache: GDB can now automatically save indices of DWARF
1449 symbols on disk to speed up further loading of the same binaries.
1451 * Ada task switching is now supported on aarch64-elf targets when
1452 debugging a program using the Ravenscar Profile. For more information,
1453 see the "Tasking Support when using the Ravenscar Profile" section
1454 in the GDB user manual.
1456 * GDB in batch mode now exits with status 1 if the last command to be
1459 * The RISC-V target now supports target descriptions.
1461 * System call catchpoints now support system call aliases on FreeBSD.
1462 When the ABI of a system call changes in FreeBSD, this is
1463 implemented by leaving a compatibility system call using the old ABI
1464 at the existing number and allocating a new system call number for
1465 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1466 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1467 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1468 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1469 so that a system call catchpoint for the 'kevent' system call will
1470 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1471 binaries. This ensures that 'kevent' system calls are caught for
1472 binaries using either the old or new ABIs.
1474 * Terminal styling is now available for the CLI and the TUI. GNU
1475 Source Highlight can additionally be used to provide styling of
1476 source code snippets. See the "set style" commands, below, for more
1479 * Removed support for old demangling styles arm, edg, gnu, hp and
1484 set debug compile-cplus-types
1485 show debug compile-cplus-types
1486 Control the display of debug output about type conversion in the
1487 C++ compile feature. Commands have no effect while compiling
1488 for other languages.
1492 Control whether debug output about files/functions skipping is
1495 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1496 Apply a command to some frames.
1497 FLAG arguments allow to control what output to produce and how to handle
1498 errors raised when applying COMMAND to a frame.
1501 Apply a command to all threads (ignoring errors and empty output).
1502 Shortcut for 'thread apply all -s COMMAND'.
1505 Apply a command to all frames (ignoring errors and empty output).
1506 Shortcut for 'frame apply all -s COMMAND'.
1509 Apply a command to all frames of all threads (ignoring errors and empty
1511 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1513 maint set dwarf unwinders (on|off)
1514 maint show dwarf unwinders
1515 Control whether DWARF unwinders can be used.
1518 Display a list of open files for a process.
1522 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1523 These commands all now take a frame specification which
1524 is either a frame level, or one of the keywords 'level', 'address',
1525 'function', or 'view' followed by a parameter. Selecting a frame by
1526 address, or viewing a frame outside the current backtrace now
1527 requires the use of a keyword. Selecting a frame by level is
1528 unchanged. The MI comment "-stack-select-frame" is unchanged.
1530 target remote FILENAME
1531 target extended-remote FILENAME
1532 If FILENAME is a Unix domain socket, GDB will attempt to connect
1533 to this socket instead of opening FILENAME as a character device.
1535 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1536 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1537 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1538 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1539 These commands can now print only the searched entities
1540 matching the provided regexp(s), giving a condition
1541 on the entity names or entity types. The flag -q disables
1542 printing headers or informations messages.
1548 These commands now determine the syntax for the shown entities
1549 according to the language chosen by `set language'. In particular,
1550 `set language auto' means to automatically choose the language of
1553 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1554 The 'thread apply' command accepts new FLAG arguments.
1555 FLAG arguments allow to control what output to produce and how to handle
1556 errors raised when applying COMMAND to a thread.
1558 set tui tab-width NCHARS
1559 show tui tab-width NCHARS
1560 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1562 set style enabled [on|off]
1564 Enable or disable terminal styling. Styling is enabled by default
1565 on most hosts, but disabled by default when in batch mode.
1567 set style sources [on|off]
1569 Enable or disable source code styling. Source code styling is
1570 enabled by default, but only takes effect if styling in general is
1571 enabled, and if GDB was linked with GNU Source Highlight.
1573 set style filename foreground COLOR
1574 set style filename background COLOR
1575 set style filename intensity VALUE
1576 Control the styling of file names.
1578 set style function foreground COLOR
1579 set style function background COLOR
1580 set style function intensity VALUE
1581 Control the styling of function names.
1583 set style variable foreground COLOR
1584 set style variable background COLOR
1585 set style variable intensity VALUE
1586 Control the styling of variable names.
1588 set style address foreground COLOR
1589 set style address background COLOR
1590 set style address intensity VALUE
1591 Control the styling of addresses.
1595 ** The '-data-disassemble' MI command now accepts an '-a' option to
1596 disassemble the whole function surrounding the given program
1597 counter value or function name. Support for this feature can be
1598 verified by using the "-list-features" command, which should
1599 contain "data-disassemble-a-option".
1601 ** Command responses and notifications that include a frame now include
1602 the frame's architecture in a new "arch" attribute.
1604 * New native configurations
1606 GNU/Linux/RISC-V riscv*-*-linux*
1607 FreeBSD/riscv riscv*-*-freebsd*
1611 GNU/Linux/RISC-V riscv*-*-linux*
1612 CSKY ELF csky*-*-elf
1613 CSKY GNU/LINUX csky*-*-linux
1614 FreeBSD/riscv riscv*-*-freebsd*
1616 GNU/Linux/OpenRISC or1k*-*-linux*
1620 GDB no longer supports native debugging on versions of MS-Windows
1625 ** GDB no longer supports Python versions less than 2.6.
1627 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1628 space associated to that inferior.
1630 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1631 of objfiles associated to that program space.
1633 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1634 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1637 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1638 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1639 correct and did not work properly.
1641 ** The gdb.Value type has a new constructor, which is used to construct a
1642 gdb.Value from a Python buffer object and a gdb.Type.
1648 Enable or disable the undefined behavior sanitizer. This is
1649 disabled by default, but passing --enable-ubsan=yes or
1650 --enable-ubsan=auto to configure will enable it. Enabling this can
1651 cause a performance penalty. The undefined behavior sanitizer was
1652 first introduced in GCC 4.9.
1654 *** Changes in GDB 8.2
1656 * The 'set disassembler-options' command now supports specifying options
1657 for the MIPS target.
1659 * The 'symbol-file' command now accepts an '-o' option to add a relative
1660 offset to all sections.
1662 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1663 a relative offset to all sections, but it allows to override the load
1664 address of individual sections using '-s'.
1666 * The 'add-symbol-file' command no longer requires the second argument
1667 (address of the text section).
1669 * The endianness used with the 'set endian auto' mode in the absence of
1670 an executable selected for debugging is now the last endianness chosen
1671 either by one of the 'set endian big' and 'set endian little' commands
1672 or by inferring from the last executable used, rather than the startup
1675 * The pager now allows a "c" response, meaning to disable the pager
1676 for the rest of the current command.
1678 * The commands 'info variables/functions/types' now show the source line
1679 numbers of symbol definitions when available.
1681 * 'info proc' now works on running processes on FreeBSD systems and core
1682 files created on FreeBSD systems.
1684 * C expressions can now use _Alignof, and C++ expressions can now use
1687 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1688 the vector length while the process is running.
1694 Control display of debugging info regarding the FreeBSD native target.
1696 set|show varsize-limit
1697 This new setting allows the user to control the maximum size of Ada
1698 objects being printed when those objects have a variable type,
1699 instead of that maximum size being hardcoded to 65536 bytes.
1701 set|show record btrace cpu
1702 Controls the processor to be used for enabling errata workarounds for
1703 branch trace decode.
1705 maint check libthread-db
1706 Run integrity checks on the current inferior's thread debugging
1709 maint set check-libthread-db (on|off)
1710 maint show check-libthread-db
1711 Control whether to run integrity checks on inferior specific thread
1712 debugging libraries as they are loaded. The default is not to
1713 perform such checks.
1717 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1719 ** The commands attached to a breakpoint can be set by assigning to
1720 the breakpoint's "commands" field.
1722 ** gdb.execute can now execute multi-line gdb commands.
1724 ** The new functions gdb.convenience_variable and
1725 gdb.set_convenience_variable can be used to get and set the value
1726 of convenience variables.
1728 ** A gdb.Parameter will no longer print the "set" help text on an
1729 ordinary "set"; instead by default a "set" will be silent unless
1730 the get_set_string method returns a non-empty string.
1734 RiscV ELF riscv*-*-elf
1736 * Removed targets and native configurations
1738 m88k running OpenBSD m88*-*-openbsd*
1739 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1740 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1741 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1743 * Aarch64/Linux hardware watchpoints improvements
1745 Hardware watchpoints on unaligned addresses are now properly
1746 supported when running Linux kernel 4.10 or higher: read and access
1747 watchpoints are no longer spuriously missed, and all watchpoints
1748 lengths between 1 and 8 bytes are supported. On older kernels,
1749 watchpoints set on unaligned addresses are no longer missed, with
1750 the tradeoff that there is a possibility of false hits being
1755 --enable-codesign=CERT
1756 This can be used to invoke "codesign -s CERT" after building gdb.
1757 This option is useful on macOS, where code signing is required for
1758 gdb to work properly.
1760 --disable-gdbcli has been removed
1761 This is now silently accepted, but does nothing.
1763 *** Changes in GDB 8.1
1765 * GDB now supports dynamically creating arbitrary register groups specified
1766 in XML target descriptions. This allows for finer grain grouping of
1767 registers on systems with a large amount of registers.
1769 * The 'ptype' command now accepts a '/o' flag, which prints the
1770 offsets and sizes of fields in a struct, like the pahole(1) tool.
1772 * New "--readnever" command line option instructs GDB to not read each
1773 symbol file's symbolic debug information. This makes startup faster
1774 but at the expense of not being able to perform symbolic debugging.
1775 This option is intended for use cases where symbolic debugging will
1776 not be used, e.g., when you only need to dump the debuggee's core.
1778 * GDB now uses the GNU MPFR library, if available, to emulate target
1779 floating-point arithmetic during expression evaluation when the target
1780 uses different floating-point formats than the host. At least version
1781 3.1 of GNU MPFR is required.
1783 * GDB now supports access to the guarded-storage-control registers and the
1784 software-based guarded-storage broadcast control registers on IBM z14.
1786 * On Unix systems, GDB now supports transmitting environment variables
1787 that are to be set or unset to GDBserver. These variables will
1788 affect the environment to be passed to the remote inferior.
1790 To inform GDB of environment variables that are to be transmitted to
1791 GDBserver, use the "set environment" command. Only user set
1792 environment variables are sent to GDBserver.
1794 To inform GDB of environment variables that are to be unset before
1795 the remote inferior is started by the GDBserver, use the "unset
1796 environment" command.
1798 * Completion improvements
1800 ** GDB can now complete function parameters in linespecs and
1801 explicit locations without quoting. When setting breakpoints,
1802 quoting around functions names to help with TAB-completion is
1803 generally no longer necessary. For example, this now completes
1806 (gdb) b function(in[TAB]
1807 (gdb) b function(int)
1809 Related, GDB is no longer confused with completing functions in
1810 C++ anonymous namespaces:
1813 (gdb) b (anonymous namespace)::[TAB][TAB]
1814 (anonymous namespace)::a_function()
1815 (anonymous namespace)::b_function()
1817 ** GDB now has much improved linespec and explicit locations TAB
1818 completion support, that better understands what you're
1819 completing and offers better suggestions. For example, GDB no
1820 longer offers data symbols as possible completions when you're
1821 setting a breakpoint.
1823 ** GDB now TAB-completes label symbol names.
1825 ** The "complete" command now mimics TAB completion accurately.
1827 * New command line options (gcore)
1830 Dump all memory mappings.
1832 * Breakpoints on C++ functions are now set on all scopes by default
1834 By default, breakpoints on functions/methods are now interpreted as
1835 specifying all functions with the given name ignoring missing
1836 leading scopes (namespaces and classes).
1838 For example, assuming a C++ program with symbols named:
1843 both commands "break func()" and "break B::func()" set a breakpoint
1846 You can use the new flag "-qualified" to override this. This makes
1847 GDB interpret the specified function name as a complete
1848 fully-qualified name instead. For example, using the same C++
1849 program, the "break -q B::func" command sets a breakpoint on
1850 "B::func", only. A parameter has been added to the Python
1851 gdb.Breakpoint constructor to achieve the same result when creating
1852 a breakpoint from Python.
1854 * Breakpoints on functions marked with C++ ABI tags
1856 GDB can now set breakpoints on functions marked with C++ ABI tags
1857 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1858 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1860 Functions with a C++11 abi tag are demangled/displayed like this:
1862 function[abi:cxx11](int)
1865 You can now set a breakpoint on such functions simply as if they had
1868 (gdb) b function(int)
1870 Or if you need to disambiguate between tags, like:
1872 (gdb) b function[abi:other_tag](int)
1874 Tab completion was adjusted accordingly as well.
1878 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1879 gdb.new_thread are emitted. See the manual for further
1880 description of these.
1882 ** A new function, "gdb.rbreak" has been added to the Python API.
1883 This function allows the setting of a large number of breakpoints
1884 via a regex pattern in Python. See the manual for further details.
1886 ** Python breakpoints can now accept explicit locations. See the
1887 manual for a further description of this feature.
1890 * New features in the GDB remote stub, GDBserver
1892 ** GDBserver is now able to start inferior processes with a
1893 specified initial working directory.
1895 The user can set the desired working directory to be used from
1896 GDB using the new "set cwd" command.
1898 ** New "--selftest" command line option runs some GDBserver self
1899 tests. These self tests are disabled in releases.
1901 ** On Unix systems, GDBserver now does globbing expansion and variable
1902 substitution in inferior command line arguments.
1904 This is done by starting inferiors using a shell, like GDB does.
1905 See "set startup-with-shell" in the user manual for how to disable
1906 this from GDB when using "target extended-remote". When using
1907 "target remote", you can disable the startup with shell by using the
1908 new "--no-startup-with-shell" GDBserver command line option.
1910 ** On Unix systems, GDBserver now supports receiving environment
1911 variables that are to be set or unset from GDB. These variables
1912 will affect the environment to be passed to the inferior.
1914 * When catching an Ada exception raised with a message, GDB now prints
1915 the message in the catchpoint hit notification. In GDB/MI mode, that
1916 information is provided as an extra field named "exception-message"
1917 in the *stopped notification.
1919 * Trait objects can now be inspected When debugging Rust code. This
1920 requires compiler support which will appear in Rust 1.24.
1922 * New remote packets
1924 QEnvironmentHexEncoded
1925 Inform GDBserver of an environment variable that is to be passed to
1926 the inferior when starting it.
1929 Inform GDBserver of an environment variable that is to be unset
1930 before starting the remote inferior.
1933 Inform GDBserver that the environment should be reset (i.e.,
1934 user-set environment variables should be unset).
1937 Indicates whether the inferior must be started with a shell or not.
1940 Tell GDBserver that the inferior to be started should use a specific
1943 * The "maintenance print c-tdesc" command now takes an optional
1944 argument which is the file name of XML target description.
1946 * The "maintenance selftest" command now takes an optional argument to
1947 filter the tests to be run.
1949 * The "enable", and "disable" commands now accept a range of
1950 breakpoint locations, e.g. "enable 1.3-5".
1955 Set and show the current working directory for the inferior.
1957 set|show compile-gcc
1958 Set and show compilation command used for compiling and injecting code
1959 with the 'compile' commands.
1961 set debug separate-debug-file
1962 show debug separate-debug-file
1963 Control the display of debug output about separate debug file search.
1965 set dump-excluded-mappings
1966 show dump-excluded-mappings
1967 Control whether mappings marked with the VM_DONTDUMP flag should be
1968 dumped when generating a core file.
1970 maint info selftests
1971 List the registered selftests.
1974 Start the debugged program stopping at the first instruction.
1977 Control display of debugging messages related to OpenRISC targets.
1979 set|show print type nested-type-limit
1980 Set and show the limit of nesting level for nested types that the
1981 type printer will show.
1983 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1986 * Safer/improved support for debugging with no debug info
1988 GDB no longer assumes functions with no debug information return
1991 This means that GDB now refuses to call such functions unless you
1992 tell it the function's type, by either casting the call to the
1993 declared return type, or by casting the function to a function
1994 pointer of the right type, and calling that:
1996 (gdb) p getenv ("PATH")
1997 'getenv' has unknown return type; cast the call to its declared return type
1998 (gdb) p (char *) getenv ("PATH")
1999 $1 = 0x7fffffffe "/usr/local/bin:/"...
2000 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2001 $2 = 0x7fffffffe "/usr/local/bin:/"...
2003 Similarly, GDB no longer assumes that global variables with no debug
2004 info have type 'int', and refuses to print the variable's value
2005 unless you tell it the variable's type:
2008 'var' has unknown type; cast it to its declared type
2012 * New native configurations
2014 FreeBSD/aarch64 aarch64*-*-freebsd*
2015 FreeBSD/arm arm*-*-freebsd*
2019 FreeBSD/aarch64 aarch64*-*-freebsd*
2020 FreeBSD/arm arm*-*-freebsd*
2021 OpenRISC ELF or1k*-*-elf
2023 * Removed targets and native configurations
2025 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2027 *** Changes in GDB 8.0
2029 * GDB now supports access to the PKU register on GNU/Linux. The register is
2030 added by the Memory Protection Keys for Userspace feature which will be
2031 available in future Intel CPUs.
2033 * GDB now supports C++11 rvalue references.
2037 ** New functions to start, stop and access a running btrace recording.
2038 ** Rvalue references are now supported in gdb.Type.
2040 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2043 * Building GDB and GDBserver now requires a C++11 compiler.
2045 For example, GCC 4.8 or later.
2047 It is no longer possible to build GDB or GDBserver with a C
2048 compiler. The --disable-build-with-cxx configure option has been
2051 * Building GDB and GDBserver now requires GNU make >= 3.81.
2053 It is no longer supported to build GDB or GDBserver with another
2054 implementation of the make program or an earlier version of GNU make.
2056 * Native debugging on MS-Windows supports command-line redirection
2058 Command-line arguments used for starting programs on MS-Windows can
2059 now include redirection symbols supported by native Windows shells,
2060 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2061 as "run", "start", and "set args", as well as the corresponding MI
2064 * Support for thread names on MS-Windows.
2066 GDB now catches and handles the special exception that programs
2067 running on MS-Windows use to assign names to threads in the
2070 * Support for Java programs compiled with gcj has been removed.
2072 * User commands now accept an unlimited number of arguments.
2073 Previously, only up to 10 was accepted.
2075 * The "eval" command now expands user-defined command arguments.
2077 This makes it easier to process a variable number of arguments:
2082 eval "print $arg%d", $i
2087 * Target descriptions can now describe registers for sparc32 and sparc64.
2089 * GDB now supports DWARF version 5 (debug information format).
2090 Its .debug_names index is not yet supported.
2092 * New native configurations
2094 FreeBSD/mips mips*-*-freebsd
2098 Synopsys ARC arc*-*-elf32
2099 FreeBSD/mips mips*-*-freebsd
2101 * Removed targets and native configurations
2103 Alpha running FreeBSD alpha*-*-freebsd*
2104 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2109 Erases all the flash memory regions reported by the target.
2111 maint print arc arc-instruction address
2112 Print internal disassembler information about instruction at a given address.
2116 set disassembler-options
2117 show disassembler-options
2118 Controls the passing of target specific information to the disassembler.
2119 If it is necessary to specify more than one disassembler option then
2120 multiple options can be placed together into a comma separated list.
2121 The default value is the empty string. Currently, the only supported
2122 targets are ARM, PowerPC and S/390.
2127 Erases all the flash memory regions reported by the target. This is
2128 equivalent to the CLI command flash-erase.
2130 -file-list-shared-libraries
2131 List the shared libraries in the program. This is
2132 equivalent to the CLI command "info shared".
2135 Catchpoints stopping the program when Ada exceptions are
2136 handled. This is equivalent to the CLI command "catch handlers".
2138 *** Changes in GDB 7.12
2140 * GDB and GDBserver now build with a C++ compiler by default.
2142 The --enable-build-with-cxx configure option is now enabled by
2143 default. One must now explicitly configure with
2144 --disable-build-with-cxx in order to build with a C compiler. This
2145 option will be removed in a future release.
2147 * GDBserver now supports recording btrace without maintaining an active
2150 * GDB now supports a negative repeat count in the 'x' command to examine
2151 memory backward from the given address. For example:
2154 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2155 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2156 (gdb) x/-5i 0x0000000000400580
2157 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2158 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2159 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2160 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2161 0x40057b <main(int, char**)+25>:
2162 callq 0x400536 <Func1(int, char const*)>
2164 * Fortran: Support structures with fields of dynamic types and
2165 arrays of dynamic types.
2167 * The symbol dumping maintenance commands have new syntax.
2168 maint print symbols [-pc address] [--] [filename]
2169 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2170 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2171 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2172 maint print msymbols [-objfile objfile] [--] [filename]
2174 * GDB now supports multibit bitfields and enums in target register
2177 * New Python-based convenience function $_as_string(val), which returns
2178 the textual representation of a value. This function is especially
2179 useful to obtain the text label of an enum value.
2181 * Intel MPX bound violation handling.
2183 Segmentation faults caused by a Intel MPX boundary violation
2184 now display the kind of violation (upper or lower), the memory
2185 address accessed and the memory bounds, along with the usual
2186 signal received and code location.
2190 Program received signal SIGSEGV, Segmentation fault
2191 Upper bound violation while accessing address 0x7fffffffc3b3
2192 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2193 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2195 * Rust language support.
2196 GDB now supports debugging programs written in the Rust programming
2197 language. See https://www.rust-lang.org/ for more information about
2200 * Support for running interpreters on specified input/output devices
2202 GDB now supports a new mechanism that allows frontends to provide
2203 fully featured GDB console views, as a better alternative to
2204 building such views on top of the "-interpreter-exec console"
2205 command. See the new "new-ui" command below. With that command,
2206 frontends can now start GDB in the traditional command-line mode
2207 running in an embedded terminal emulator widget, and create a
2208 separate MI interpreter running on a specified i/o device. In this
2209 way, GDB handles line editing, history, tab completion, etc. in the
2210 console all by itself, and the GUI uses the separate MI interpreter
2211 for its own control and synchronization, invisible to the command
2214 * The "catch syscall" command catches groups of related syscalls.
2216 The "catch syscall" command now supports catching a group of related
2217 syscalls using the 'group:' or 'g:' prefix.
2222 skip -gfile file-glob-pattern
2223 skip -function function
2224 skip -rfunction regular-expression
2225 A generalized form of the skip command, with new support for
2226 glob-style file names and regular expressions for function names.
2227 Additionally, a file spec and a function spec may now be combined.
2229 maint info line-table REGEXP
2230 Display the contents of GDB's internal line table data structure.
2233 Run any GDB unit tests that were compiled in.
2236 Start a new user interface instance running INTERP as interpreter,
2237 using the TTY file for input/output.
2241 ** gdb.Breakpoint objects have a new attribute "pending", which
2242 indicates whether the breakpoint is pending.
2243 ** Three new breakpoint-related events have been added:
2244 gdb.breakpoint_created, gdb.breakpoint_modified, and
2245 gdb.breakpoint_deleted.
2247 signal-event EVENTID
2248 Signal ("set") the given MS-Windows event object. This is used in
2249 conjunction with the Windows JIT debugging (AeDebug) support, where
2250 the OS suspends a crashing process until a debugger can attach to
2251 it. Resuming the crashing process, in order to debug it, is done by
2252 signalling an event.
2254 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2255 was added in GDBserver, including JIT compiling fast tracepoint's
2256 conditional expression bytecode into native code.
2258 * Support for various remote target protocols and ROM monitors has
2261 target m32rsdi Remote M32R debugging over SDI
2262 target mips MIPS remote debugging protocol
2263 target pmon PMON ROM monitor
2264 target ddb NEC's DDB variant of PMON for Vr4300
2265 target rockhopper NEC RockHopper variant of PMON
2266 target lsi LSI variant of PMO
2268 * Support for tracepoints and fast tracepoints on powerpc-linux,
2269 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2270 including JIT compiling fast tracepoint's conditional expression
2271 bytecode into native code.
2273 * MI async record =record-started now includes the method and format used for
2274 recording. For example:
2276 =record-started,thread-group="i1",method="btrace",format="bts"
2278 * MI async record =thread-selected now includes the frame field. For example:
2280 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2284 Andes NDS32 nds32*-*-elf
2286 *** Changes in GDB 7.11
2288 * GDB now supports debugging kernel-based threads on FreeBSD.
2290 * Per-inferior thread numbers
2292 Thread numbers are now per inferior instead of global. If you're
2293 debugging multiple inferiors, GDB displays thread IDs using a
2294 qualified INF_NUM.THR_NUM form. For example:
2298 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2299 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2300 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2301 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2303 As consequence, thread numbers as visible in the $_thread
2304 convenience variable and in Python's InferiorThread.num attribute
2305 are no longer unique between inferiors.
2307 GDB now maintains a second thread ID per thread, referred to as the
2308 global thread ID, which is the new equivalent of thread numbers in
2309 previous releases. See also $_gthread below.
2311 For backwards compatibility, MI's thread IDs always refer to global
2314 * Commands that accept thread IDs now accept the qualified
2315 INF_NUM.THR_NUM form as well. For example:
2318 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2321 * In commands that accept a list of thread IDs, you can now refer to
2322 all threads of an inferior using a star wildcard. GDB accepts
2323 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2324 refer to all threads of the current inferior. For example, "info
2327 * You can use "info threads -gid" to display the global thread ID of
2330 * The new convenience variable $_gthread holds the global number of
2333 * The new convenience variable $_inferior holds the number of the
2336 * GDB now displays the ID and name of the thread that hit a breakpoint
2337 or received a signal, if your program is multi-threaded. For
2340 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2341 Thread 1 "main" received signal SIGINT, Interrupt.
2343 * Record btrace now supports non-stop mode.
2345 * Support for tracepoints on aarch64-linux was added in GDBserver.
2347 * The 'record instruction-history' command now indicates speculative execution
2348 when using the Intel Processor Trace recording format.
2350 * GDB now allows users to specify explicit locations, bypassing
2351 the linespec parser. This feature is also available to GDB/MI
2354 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2355 GDB now is able to debug both AArch64 applications and ARM applications
2358 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2359 including JIT compiling fast tracepoint's conditional expression bytecode
2362 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2364 * "info threads", "info inferiors", "info display", "info checkpoints"
2365 and "maint info program-spaces" now list the corresponding items in
2366 ascending ID order, for consistency with all other "info" commands.
2368 * In Ada, the overloads selection menu has been enhanced to display the
2369 parameter types and the return types for the matching overloaded subprograms.
2373 maint set target-non-stop (on|off|auto)
2374 maint show target-non-stop
2375 Control whether GDB targets always operate in non-stop mode even if
2376 "set non-stop" is "off". The default is "auto", meaning non-stop
2377 mode is enabled if supported by the target.
2379 maint set bfd-sharing
2380 maint show bfd-sharing
2381 Control the reuse of bfd objects.
2384 show debug bfd-cache
2385 Control display of debugging info regarding bfd caching.
2389 Control display of debugging info regarding FreeBSD threads.
2391 set remote multiprocess-extensions-packet
2392 show remote multiprocess-extensions-packet
2393 Set/show the use of the remote protocol multiprocess extensions.
2395 set remote thread-events
2396 show remote thread-events
2397 Set/show the use of thread create/exit events.
2399 set ada print-signatures on|off
2400 show ada print-signatures"
2401 Control whether parameter types and return types are displayed in overloads
2402 selection menus. It is activated (@code{on}) by default.
2406 Controls the maximum size of memory, in bytes, that GDB will
2407 allocate for value contents. Prevents incorrect programs from
2408 causing GDB to allocate overly large buffers. Default is 64k.
2410 * The "disassemble" command accepts a new modifier: /s.
2411 It prints mixed source+disassembly like /m with two differences:
2412 - disassembled instructions are now printed in program order, and
2413 - and source for all relevant files is now printed.
2414 The "/m" option is now considered deprecated: its "source-centric"
2415 output hasn't proved useful in practice.
2417 * The "record instruction-history" command accepts a new modifier: /s.
2418 It behaves exactly like /m and prints mixed source+disassembly.
2420 * The "set scheduler-locking" command supports a new mode "replay".
2421 It behaves like "off" in record mode and like "on" in replay mode.
2423 * Support for various ROM monitors has been removed:
2425 target dbug dBUG ROM monitor for Motorola ColdFire
2426 target picobug Motorola picobug monitor
2427 target dink32 DINK32 ROM monitor for PowerPC
2428 target m32r Renesas M32R/D ROM monitor
2429 target mon2000 mon2000 ROM monitor
2430 target ppcbug PPCBUG ROM monitor for PowerPC
2432 * Support for reading/writing memory and extracting values on architectures
2433 whose memory is addressable in units of any integral multiple of 8 bits.
2436 Allows to break when an Ada exception is handled.
2438 * New remote packets
2441 Indicates that an exec system call was executed.
2443 exec-events feature in qSupported
2444 The qSupported packet allows GDB to request support for exec
2445 events using the new 'gdbfeature' exec-event, and the qSupported
2446 response can contain the corresponding 'stubfeature'. Set and
2447 show commands can be used to display whether these features are enabled.
2450 Equivalent to interrupting with the ^C character, but works in
2453 thread created stop reason (T05 create:...)
2454 Indicates that the thread was just created and is stopped at entry.
2456 thread exit stop reply (w exitcode;tid)
2457 Indicates that the thread has terminated.
2460 Enables/disables thread create and exit event reporting. For
2461 example, this is used in non-stop mode when GDB stops a set of
2462 threads and synchronously waits for the their corresponding stop
2463 replies. Without exit events, if one of the threads exits, GDB
2464 would hang forever not knowing that it should no longer expect a
2465 stop for that same thread.
2468 Indicates that there are no resumed threads left in the target (all
2469 threads are stopped). The remote stub reports support for this stop
2470 reply to GDB's qSupported query.
2473 Enables/disables catching syscalls from the inferior process.
2474 The remote stub reports support for this packet to GDB's qSupported query.
2476 syscall_entry stop reason
2477 Indicates that a syscall was just called.
2479 syscall_return stop reason
2480 Indicates that a syscall just returned.
2482 * Extended-remote exec events
2484 ** GDB now has support for exec events on extended-remote Linux targets.
2485 For such targets with Linux kernels 2.5.46 and later, this enables
2486 follow-exec-mode and exec catchpoints.
2488 set remote exec-event-feature-packet
2489 show remote exec-event-feature-packet
2490 Set/show the use of the remote exec event feature.
2492 * Thread names in remote protocol
2494 The reply to qXfer:threads:read may now include a name attribute for each
2497 * Target remote mode fork and exec events
2499 ** GDB now has support for fork and exec events on target remote mode
2500 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2501 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2502 fork and exec catchpoints.
2504 * Remote syscall events
2506 ** GDB now has support for catch syscall on remote Linux targets,
2507 currently enabled on x86/x86_64 architectures.
2509 set remote catch-syscall-packet
2510 show remote catch-syscall-packet
2511 Set/show the use of the remote catch syscall feature.
2515 ** The -var-set-format command now accepts the zero-hexadecimal
2516 format. It outputs data in hexadecimal format with zero-padding on the
2521 ** gdb.InferiorThread objects have a new attribute "global_num",
2522 which refers to the thread's global thread ID. The existing
2523 "num" attribute now refers to the thread's per-inferior number.
2524 See "Per-inferior thread numbers" above.
2525 ** gdb.InferiorThread objects have a new attribute "inferior", which
2526 is the Inferior object the thread belongs to.
2528 *** Changes in GDB 7.10
2530 * Support for process record-replay and reverse debugging on aarch64*-linux*
2531 targets has been added. GDB now supports recording of A64 instruction set
2532 including advance SIMD instructions.
2534 * Support for Sun's version of the "stabs" debug file format has been removed.
2536 * GDB now honors the content of the file /proc/PID/coredump_filter
2537 (PID is the process ID) on GNU/Linux systems. This file can be used
2538 to specify the types of memory mappings that will be included in a
2539 corefile. For more information, please refer to the manual page of
2540 "core(5)". GDB also has a new command: "set use-coredump-filter
2541 on|off". It allows to set whether GDB will read the content of the
2542 /proc/PID/coredump_filter file when generating a corefile.
2544 * The "info os" command on GNU/Linux can now display information on
2546 "info os cpus" Listing of all cpus/cores on the system
2548 * GDB has two new commands: "set serial parity odd|even|none" and
2549 "show serial parity". These allows to set or show parity for the
2552 * The "info source" command now displays the producer string if it was
2553 present in the debug info. This typically includes the compiler version
2554 and may include things like its command line arguments.
2556 * The "info dll", an alias of the "info sharedlibrary" command,
2557 is now available on all platforms.
2559 * Directory names supplied to the "set sysroot" commands may be
2560 prefixed with "target:" to tell GDB to access shared libraries from
2561 the target system, be it local or remote. This replaces the prefix
2562 "remote:". The default sysroot has been changed from "" to
2563 "target:". "remote:" is automatically converted to "target:" for
2564 backward compatibility.
2566 * The system root specified by "set sysroot" will be prepended to the
2567 filename of the main executable (if reported to GDB as absolute by
2568 the operating system) when starting processes remotely, and when
2569 attaching to already-running local or remote processes.
2571 * GDB now supports automatic location and retrieval of executable
2572 files from remote targets. Remote debugging can now be initiated
2573 using only a "target remote" or "target extended-remote" command
2574 (no "set sysroot" or "file" commands are required). See "New remote
2577 * The "dump" command now supports verilog hex format.
2579 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2581 * On GNU/Linux, GDB and gdbserver are now able to access executable
2582 and shared library files without a "set sysroot" command when
2583 attaching to processes running in different mount namespaces from
2584 the debugger. This makes it possible to attach to processes in
2585 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2586 See "New remote packets" below.
2588 * The "tui reg" command now provides completion for all of the
2589 available register groups, including target specific groups.
2591 * The HISTSIZE environment variable is no longer read when determining
2592 the size of GDB's command history. GDB now instead reads the dedicated
2593 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2594 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2599 ** Memory ports can now be unbuffered.
2603 ** gdb.Objfile objects have a new attribute "username",
2604 which is the name of the objfile as specified by the user,
2605 without, for example, resolving symlinks.
2606 ** You can now write frame unwinders in Python.
2607 ** gdb.Type objects have a new method "optimized_out",
2608 returning optimized out gdb.Value instance of this type.
2609 ** gdb.Value objects have new methods "reference_value" and
2610 "const_value" which return a reference to the value and a
2611 "const" version of the value respectively.
2615 maint print symbol-cache
2616 Print the contents of the symbol cache.
2618 maint print symbol-cache-statistics
2619 Print statistics of symbol cache usage.
2621 maint flush-symbol-cache
2622 Flush the contents of the symbol cache.
2626 Start branch trace recording using Branch Trace Store (BTS) format.
2629 Evaluate expression by using the compiler and print result.
2633 Explicit commands for enabling and disabling tui mode.
2636 set mpx bound on i386 and amd64
2637 Support for bound table investigation on Intel MPX enabled applications.
2641 Start branch trace recording using Intel Processor Trace format.
2644 Print information about branch tracing internals.
2646 maint btrace packet-history
2647 Print the raw branch tracing data.
2649 maint btrace clear-packet-history
2650 Discard the stored raw branch tracing data.
2653 Discard all branch tracing data. It will be fetched and processed
2654 anew by the next "record" command.
2659 Renamed from "set debug dwarf2-die".
2660 show debug dwarf-die
2661 Renamed from "show debug dwarf2-die".
2663 set debug dwarf-read
2664 Renamed from "set debug dwarf2-read".
2665 show debug dwarf-read
2666 Renamed from "show debug dwarf2-read".
2668 maint set dwarf always-disassemble
2669 Renamed from "maint set dwarf2 always-disassemble".
2670 maint show dwarf always-disassemble
2671 Renamed from "maint show dwarf2 always-disassemble".
2673 maint set dwarf max-cache-age
2674 Renamed from "maint set dwarf2 max-cache-age".
2675 maint show dwarf max-cache-age
2676 Renamed from "maint show dwarf2 max-cache-age".
2678 set debug dwarf-line
2679 show debug dwarf-line
2680 Control display of debugging info regarding DWARF line processing.
2683 show max-completions
2684 Set the maximum number of candidates to be considered during
2685 completion. The default value is 200. This limit allows GDB
2686 to avoid generating large completion lists, the computation of
2687 which can cause the debugger to become temporarily unresponsive.
2689 set history remove-duplicates
2690 show history remove-duplicates
2691 Control the removal of duplicate history entries.
2693 maint set symbol-cache-size
2694 maint show symbol-cache-size
2695 Control the size of the symbol cache.
2697 set|show record btrace bts buffer-size
2698 Set and show the size of the ring buffer used for branch tracing in
2700 The obtained size may differ from the requested size. Use "info
2701 record" to see the obtained buffer size.
2703 set debug linux-namespaces
2704 show debug linux-namespaces
2705 Control display of debugging info regarding Linux namespaces.
2707 set|show record btrace pt buffer-size
2708 Set and show the size of the ring buffer used for branch tracing in
2709 Intel Processor Trace format.
2710 The obtained size may differ from the requested size. Use "info
2711 record" to see the obtained buffer size.
2713 maint set|show btrace pt skip-pad
2714 Set and show whether PAD packets are skipped when computing the
2717 * The command 'thread apply all' can now support new option '-ascending'
2718 to call its specified command for all threads in ascending order.
2720 * Python/Guile scripting
2722 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2723 special section named `.debug_gdb_scripts'.
2725 * New remote packets
2727 qXfer:btrace-conf:read
2728 Return the branch trace configuration for the current thread.
2730 Qbtrace-conf:bts:size
2731 Set the requested ring buffer size for branch tracing in BTS format.
2734 Enable Intel Processor Trace-based branch tracing for the current
2735 process. The remote stub reports support for this packet to GDB's
2738 Qbtrace-conf:pt:size
2739 Set the requested ring buffer size for branch tracing in Intel Processor
2743 Indicates a memory breakpoint instruction was executed, irrespective
2744 of whether it was GDB that planted the breakpoint or the breakpoint
2745 is hardcoded in the program. This is required for correct non-stop
2749 Indicates the target stopped for a hardware breakpoint. This is
2750 required for correct non-stop mode operation.
2753 Return information about files on the remote system.
2755 qXfer:exec-file:read
2756 Return the full absolute name of the file that was executed to
2757 create a process running on the remote system.
2760 Select the filesystem on which vFile: operations with filename
2761 arguments will operate. This is required for GDB to be able to
2762 access files on remote targets where the remote stub does not
2763 share a common filesystem with the inferior(s).
2766 Indicates that a fork system call was executed.
2769 Indicates that a vfork system call was executed.
2771 vforkdone stop reason
2772 Indicates that a vfork child of the specified process has executed
2773 an exec or exit, allowing the vfork parent to resume execution.
2775 fork-events and vfork-events features in qSupported
2776 The qSupported packet allows GDB to request support for fork and
2777 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2778 and the qSupported response can contain the corresponding
2779 'stubfeatures'. Set and show commands can be used to display
2780 whether these features are enabled.
2782 * Extended-remote fork events
2784 ** GDB now has support for fork events on extended-remote Linux
2785 targets. For targets with Linux kernels 2.5.60 and later, this
2786 enables follow-fork-mode and detach-on-fork for both fork and
2787 vfork, as well as fork and vfork catchpoints.
2789 * The info record command now shows the recording format and the
2790 branch tracing configuration for the current thread when using
2791 the btrace record target.
2792 For the BTS format, it shows the ring buffer size.
2794 * GDB now has support for DTrace USDT (Userland Static Defined
2795 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2797 * GDB now supports access to vector registers on S/390 GNU/Linux
2800 * Removed command line options
2802 -xdb HP-UX XDB compatibility mode.
2804 * Removed targets and native configurations
2806 HP/PA running HP-UX hppa*-*-hpux*
2807 Itanium running HP-UX ia64-*-hpux*
2809 * New configure options
2812 This configure option allows the user to build GDB with support for
2813 Intel Processor Trace (default: auto). This requires libipt.
2815 --with-libipt-prefix=PATH
2816 Specify the path to the version of libipt that GDB should use.
2817 $PATH/include should contain the intel-pt.h header and
2818 $PATH/lib should contain the libipt.so library.
2820 *** Changes in GDB 7.9.1
2824 ** Xmethods can now specify a result type.
2826 *** Changes in GDB 7.9
2828 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2832 ** You can now access frame registers from Python scripts.
2833 ** New attribute 'producer' for gdb.Symtab objects.
2834 ** gdb.Objfile objects have a new attribute "progspace",
2835 which is the gdb.Progspace object of the containing program space.
2836 ** gdb.Objfile objects have a new attribute "owner".
2837 ** gdb.Objfile objects have a new attribute "build_id",
2838 which is the build ID generated when the file was built.
2839 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2840 ** A new event "gdb.clear_objfiles" has been added, triggered when
2841 selecting a new file to debug.
2842 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2843 ** New function gdb.lookup_objfile.
2845 New events which are triggered when GDB modifies the state of the
2848 ** gdb.events.inferior_call_pre: Function call is about to be made.
2849 ** gdb.events.inferior_call_post: Function call has just been made.
2850 ** gdb.events.memory_changed: A memory location has been altered.
2851 ** gdb.events.register_changed: A register has been altered.
2853 * New Python-based convenience functions:
2855 ** $_caller_is(name [, number_of_frames])
2856 ** $_caller_matches(regexp [, number_of_frames])
2857 ** $_any_caller_is(name [, number_of_frames])
2858 ** $_any_caller_matches(regexp [, number_of_frames])
2860 * GDB now supports the compilation and injection of source code into
2861 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2862 to compile the source code to object code, and if successful, inject
2863 and execute that code within the current context of the inferior.
2864 Currently the C language is supported. The commands used to
2865 interface with this new feature are:
2867 compile code [-raw|-r] [--] [source code]
2868 compile file [-raw|-r] filename
2872 demangle [-l language] [--] name
2873 Demangle "name" in the specified language, or the current language
2874 if elided. This command is renamed from the "maint demangle" command.
2875 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2876 as "maint demangler-warning".
2878 queue-signal signal-name-or-number
2879 Queue a signal to be delivered to the thread when it is resumed.
2881 add-auto-load-scripts-directory directory
2882 Add entries to the list of directories from which to load auto-loaded
2885 maint print user-registers
2886 List all currently available "user" registers.
2888 compile code [-r|-raw] [--] [source code]
2889 Compile, inject, and execute in the inferior the executable object
2890 code produced by compiling the provided source code.
2892 compile file [-r|-raw] filename
2893 Compile and inject into the inferior the executable object code
2894 produced by compiling the source code stored in the filename
2897 * On resume, GDB now always passes the signal the program had stopped
2898 for to the thread the signal was sent to, even if the user changed
2899 threads before resuming. Previously GDB would often (but not
2900 always) deliver the signal to the thread that happens to be current
2903 * Conversely, the "signal" command now consistently delivers the
2904 requested signal to the current thread. GDB now asks for
2905 confirmation if the program had stopped for a signal and the user
2906 switched threads meanwhile.
2908 * "breakpoint always-inserted" modes "off" and "auto" merged.
2910 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2911 won't remove breakpoints from the target until all threads stop,
2912 even in non-stop mode. The "auto" mode has been removed, and "off"
2913 is now the default mode.
2917 set debug symbol-lookup
2918 show debug symbol-lookup
2919 Control display of debugging info regarding symbol lookup.
2923 ** The -list-thread-groups command outputs an exit-code field for
2924 inferiors that have exited.
2928 MIPS SDE mips*-sde*-elf*
2932 Support for these obsolete configurations has been removed.
2934 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2935 SGI Irix-5.x mips-*-irix5*
2936 SGI Irix-6.x mips-*-irix6*
2937 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2938 VAX running Ultrix vax-*-ultrix*
2940 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2941 and "assf"), have been removed. Use the "sharedlibrary" command, or
2942 its alias "share", instead.
2944 *** Changes in GDB 7.8
2946 * New command line options
2949 This is an alias for the --data-directory option.
2951 * GDB supports printing and modifying of variable length automatic arrays
2952 as specified in ISO C99.
2954 * The ARM simulator now supports instruction level tracing
2955 with or without disassembly.
2959 GDB now has support for scripting using Guile. Whether this is
2960 available is determined at configure time.
2961 Guile version 2.0 or greater is required.
2962 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2964 * New commands (for set/show, see "New options" below)
2968 Invoke CODE by passing it to the Guile interpreter.
2972 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2974 info auto-load guile-scripts [regexp]
2975 Print the list of automatically loaded Guile scripts.
2977 * The source command is now capable of sourcing Guile scripts.
2978 This feature is dependent on the debugger being built with Guile support.
2982 set print symbol-loading (off|brief|full)
2983 show print symbol-loading
2984 Control whether to print informational messages when loading symbol
2985 information for a file. The default is "full", but when debugging
2986 programs with large numbers of shared libraries the amount of output
2987 becomes less useful.
2989 set guile print-stack (none|message|full)
2990 show guile print-stack
2991 Show a stack trace when an error is encountered in a Guile script.
2993 set auto-load guile-scripts (on|off)
2994 show auto-load guile-scripts
2995 Control auto-loading of Guile script files.
2997 maint ada set ignore-descriptive-types (on|off)
2998 maint ada show ignore-descriptive-types
2999 Control whether the debugger should ignore descriptive types in Ada
3000 programs. The default is not to ignore the descriptive types. See
3001 the user manual for more details on descriptive types and the intended
3002 usage of this option.
3004 set auto-connect-native-target
3006 Control whether GDB is allowed to automatically connect to the
3007 native target for the run, attach, etc. commands when not connected
3008 to any target yet. See also "target native" below.
3010 set record btrace replay-memory-access (read-only|read-write)
3011 show record btrace replay-memory-access
3012 Control what memory accesses are allowed during replay.
3014 maint set target-async (on|off)
3015 maint show target-async
3016 This controls whether GDB targets operate in synchronous or
3017 asynchronous mode. Normally the default is asynchronous, if it is
3018 available; but this can be changed to more easily debug problems
3019 occurring only in synchronous mode.
3021 set mi-async (on|off)
3023 Control whether MI asynchronous mode is preferred. This supersedes
3024 "set target-async" of previous GDB versions.
3026 * "set target-async" is deprecated as a CLI option and is now an alias
3027 for "set mi-async" (only puts MI into async mode).
3029 * Background execution commands (e.g., "c&", "s&", etc.) are now
3030 possible ``out of the box'' if the target supports them. Previously
3031 the user would need to explicitly enable the possibility with the
3032 "set target-async on" command.
3034 * New features in the GDB remote stub, GDBserver
3036 ** New option --debug-format=option1[,option2,...] allows one to add
3037 additional text to each output. At present only timestamps
3038 are supported: --debug-format=timestamps.
3039 Timestamps can also be turned on with the
3040 "monitor set debug-format timestamps" command from GDB.
3042 * The 'record instruction-history' command now starts counting instructions
3043 at one. This also affects the instruction ranges reported by the
3044 'record function-call-history' command when given the /i modifier.
3046 * The command 'record function-call-history' supports a new modifier '/c' to
3047 indent the function names based on their call stack depth.
3048 The fields for the '/i' and '/l' modifier have been reordered.
3049 The source line range is now prefixed with 'at'.
3050 The instruction range is now prefixed with 'inst'.
3051 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3052 "record instruction-history" and "list" commands.
3054 * The ranges given as arguments to the 'record function-call-history' and
3055 'record instruction-history' commands are now inclusive.
3057 * The btrace record target now supports the 'record goto' command.
3058 For locations inside the execution trace, the back trace is computed
3059 based on the information stored in the execution trace.
3061 * The btrace record target supports limited reverse execution and replay.
3062 The target does not record data and therefore does not allow reading
3063 memory or registers.
3065 * The "catch syscall" command now works on s390*-linux* targets.
3067 * The "compare-sections" command is no longer specific to target
3068 remote. It now works with all targets.
3070 * All native targets are now consistently called "native".
3071 Consequently, the "target child", "target GNU", "target djgpp",
3072 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3073 commands have been replaced with "target native". The QNX/NTO port
3074 leaves the "procfs" target in place and adds a "native" target for
3075 consistency with other ports. The impact on users should be minimal
3076 as these commands previously either throwed an error, or were
3077 no-ops. The target's name is visible in the output of the following
3078 commands: "help target", "info target", "info files", "maint print
3081 * The "target native" command now connects to the native target. This
3082 can be used to launch native programs even when "set
3083 auto-connect-native-target" is set to off.
3085 * GDB now supports access to Intel MPX registers on GNU/Linux.
3087 * Support for Intel AVX-512 registers on GNU/Linux.
3088 Support displaying and modifying Intel AVX-512 registers
3089 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3091 * New remote packets
3093 qXfer:btrace:read's annex
3094 The qXfer:btrace:read packet supports a new annex 'delta' to read
3095 branch trace incrementally.
3099 ** Valid Python operations on gdb.Value objects representing
3100 structs/classes invoke the corresponding overloaded operators if
3102 ** New `Xmethods' feature in the Python API. Xmethods are
3103 additional methods or replacements for existing methods of a C++
3104 class. This feature is useful for those cases where a method
3105 defined in C++ source code could be inlined or optimized out by
3106 the compiler, making it unavailable to GDB.
3109 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3111 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3112 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3113 its alias "share", instead.
3115 * The commands "set remotebaud" and "show remotebaud" are no longer
3116 supported. Use "set serial baud" and "show serial baud" (respectively)
3121 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3122 target-async". The latter is left as a deprecated alias of the
3123 former for backward compatibility. If the target supports it,
3124 CLI background execution commands are now always possible by
3125 default, independently of whether the frontend stated a
3126 preference for asynchronous execution with "-gdb-set mi-async".
3127 Previously "-gdb-set target-async off" affected both MI execution
3128 commands and CLI execution commands.
3130 *** Changes in GDB 7.7
3132 * Improved support for process record-replay and reverse debugging on
3133 arm*-linux* targets. Support for thumb32 and syscall instruction
3134 recording has been added.
3136 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3138 * GDB now supports Fission DWP file format version 2.
3139 http://gcc.gnu.org/wiki/DebugFission
3141 * New convenience function "$_isvoid", to check whether an expression
3142 is void. A void expression is an expression where the type of the
3143 result is "void". For example, some convenience variables may be
3144 "void" when evaluated (e.g., "$_exitcode" before the execution of
3145 the program being debugged; or an undefined convenience variable).
3146 Another example, when calling a function whose return type is
3149 * The "maintenance print objfiles" command now takes an optional regexp.
3151 * The "catch syscall" command now works on arm*-linux* targets.
3153 * GDB now consistently shows "<not saved>" when printing values of
3154 registers the debug info indicates have not been saved in the frame
3155 and there's nowhere to retrieve them from
3156 (callee-saved/call-clobbered registers):
3161 (gdb) info registers rax
3164 Before, the former would print "<optimized out>", and the latter
3165 "*value not available*".
3167 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3172 ** Frame filters and frame decorators have been added.
3173 ** Temporary breakpoints are now supported.
3174 ** Line tables representation has been added.
3175 ** New attribute 'parent_type' for gdb.Field objects.
3176 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3177 ** New attribute 'name' for gdb.Type objects.
3181 Nios II ELF nios2*-*-elf
3182 Nios II GNU/Linux nios2*-*-linux
3183 Texas Instruments MSP430 msp430*-*-elf
3185 * Removed native configurations
3187 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3188 been removed. ELF variants of these configurations are kept supported.
3190 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3191 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3192 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3193 i[34567]86-*-openbsd3.[0-3]
3194 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3195 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3196 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3200 Like "catch throw", but catches a re-thrown exception.
3201 maint check-psymtabs
3202 Renamed from old "maint check-symtabs".
3204 Perform consistency checks on symtabs.
3205 maint expand-symtabs
3206 Expand symtabs matching an optional regexp.
3209 Display the details of GDB configure-time options.
3211 maint set|show per-command
3212 maint set|show per-command space
3213 maint set|show per-command time
3214 maint set|show per-command symtab
3215 Enable display of per-command gdb resource usage.
3217 remove-symbol-file FILENAME
3218 remove-symbol-file -a ADDRESS
3219 Remove a symbol file added via add-symbol-file. The file to remove
3220 can be identified by its filename or by an address that lies within
3221 the boundaries of this symbol file in memory.
3224 info exceptions REGEXP
3225 Display the list of Ada exceptions defined in the program being
3226 debugged. If provided, only the exceptions whose names match REGEXP
3231 set debug symfile off|on
3233 Control display of debugging info regarding reading symbol files and
3234 symbol tables within those files
3236 set print raw frame-arguments
3237 show print raw frame-arguments
3238 Set/show whether to print frame arguments in raw mode,
3239 disregarding any defined pretty-printers.
3241 set remote trace-status-packet
3242 show remote trace-status-packet
3243 Set/show the use of remote protocol qTStatus packet.
3247 Control display of debugging messages related to Nios II targets.
3251 Control whether target-assisted range stepping is enabled.
3253 set startup-with-shell
3254 show startup-with-shell
3255 Specifies whether Unix child processes are started via a shell or
3260 Use the target memory cache for accesses to the code segment. This
3261 improves performance of remote debugging (particularly disassembly).
3263 * You can now use a literal value 'unlimited' for options that
3264 interpret 0 or -1 as meaning "unlimited". E.g., "set
3265 trace-buffer-size unlimited" is now an alias for "set
3266 trace-buffer-size -1" and "set height unlimited" is now an alias for
3269 * The "set debug symtab-create" debugging option of GDB has been changed to
3270 accept a verbosity level. 0 means "off", 1 provides basic debugging
3271 output, and values of 2 or greater provides more verbose output.
3273 * New command-line options
3275 Display the details of GDB configure-time options.
3277 * The command 'tsave' can now support new option '-ctf' to save trace
3278 buffer in Common Trace Format.
3280 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3283 * GDB now implements the C++ 'typeid' operator.
3285 * The new convenience variable $_exception holds the exception being
3286 thrown or caught at an exception-related catchpoint.
3288 * The exception-related catchpoints, like "catch throw", now accept a
3289 regular expression which can be used to filter exceptions by type.
3291 * The new convenience variable $_exitsignal is automatically set to
3292 the terminating signal number when the program being debugged dies
3293 due to an uncaught signal.
3297 ** All MI commands now accept an optional "--language" option.
3298 Support for this feature can be verified by using the "-list-features"
3299 command, which should contain "language-option".
3301 ** The new command -info-gdb-mi-command allows the user to determine
3302 whether a GDB/MI command is supported or not.
3304 ** The "^error" result record returned when trying to execute an undefined
3305 GDB/MI command now provides a variable named "code" whose content is the
3306 "undefined-command" error code. Support for this feature can be verified
3307 by using the "-list-features" command, which should contain
3308 "undefined-command-error-code".
3310 ** The -trace-save MI command can optionally save trace buffer in Common
3313 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3315 ** The command -data-list-register-values now accepts an optional
3316 "--skip-unavailable" option. When used, only the available registers
3319 ** The new command -trace-frame-collected dumps collected variables,
3320 computed expressions, tvars, memory and registers in a traceframe.
3322 ** The commands -stack-list-locals, -stack-list-arguments and
3323 -stack-list-variables now accept an option "--skip-unavailable".
3324 When used, only the available locals or arguments are displayed.
3326 ** The -exec-run command now accepts an optional "--start" option.
3327 When used, the command follows the same semantics as the "start"
3328 command, stopping the program's execution at the start of its
3329 main subprogram. Support for this feature can be verified using
3330 the "-list-features" command, which should contain
3331 "exec-run-start-option".
3333 ** The new commands -catch-assert and -catch-exceptions insert
3334 catchpoints stopping the program when Ada exceptions are raised.
3336 ** The new command -info-ada-exceptions provides the equivalent of
3337 the new "info exceptions" command.
3339 * New system-wide configuration scripts
3340 A GDB installation now provides scripts suitable for use as system-wide
3341 configuration scripts for the following systems:
3345 * GDB now supports target-assigned range stepping with remote targets.
3346 This improves the performance of stepping source lines by reducing
3347 the number of control packets from/to GDB. See "New remote packets"
3350 * GDB now understands the element 'tvar' in the XML traceframe info.
3351 It has the id of the collected trace state variables.
3353 * On S/390 targets that provide the transactional-execution feature,
3354 the program interruption transaction diagnostic block (TDB) is now
3355 represented as a number of additional "registers" in GDB.
3357 * New remote packets
3361 The vCont packet supports a new 'r' action, that tells the remote
3362 stub to step through an address range itself, without GDB
3363 involvemement at each single-step.
3365 qXfer:libraries-svr4:read's annex
3366 The previously unused annex of the qXfer:libraries-svr4:read packet
3367 is now used to support passing an argument list. The remote stub
3368 reports support for this argument list to GDB's qSupported query.
3369 The defined arguments are "start" and "prev", used to reduce work
3370 necessary for library list updating, resulting in significant
3373 * New features in the GDB remote stub, GDBserver
3375 ** GDBserver now supports target-assisted range stepping. Currently
3376 enabled on x86/x86_64 GNU/Linux targets.
3378 ** GDBserver now adds element 'tvar' in the XML in the reply to
3379 'qXfer:traceframe-info:read'. It has the id of the collected
3380 trace state variables.
3382 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3385 * New 'z' formatter for printing and examining memory, this displays the
3386 value as hexadecimal zero padded on the left to the size of the type.
3388 * GDB can now use Windows x64 unwinding data.
3390 * The "set remotebaud" command has been replaced by "set serial baud".
3391 Similarly, "show remotebaud" has been replaced by "show serial baud".
3392 The "set remotebaud" and "show remotebaud" commands are still available
3393 to provide backward compatibility with older versions of GDB.
3395 *** Changes in GDB 7.6
3397 * Target record has been renamed to record-full.
3398 Record/replay is now enabled with the "record full" command.
3399 This also affects settings that are associated with full record/replay
3400 that have been moved from "set/show record" to "set/show record full":
3402 set|show record full insn-number-max
3403 set|show record full stop-at-limit
3404 set|show record full memory-query
3406 * A new record target "record-btrace" has been added. The new target
3407 uses hardware support to record the control-flow of a process. It
3408 does not support replaying the execution, but it implements the
3409 below new commands for investigating the recorded execution log.
3410 This new recording method can be enabled using:
3414 The "record-btrace" target is only available on Intel Atom processors
3415 and requires a Linux kernel 2.6.32 or later.
3417 * Two new commands have been added for record/replay to give information
3418 about the recorded execution without having to replay the execution.
3419 The commands are only supported by "record btrace".
3421 record instruction-history prints the execution history at
3422 instruction granularity
3424 record function-call-history prints the execution history at
3425 function granularity
3427 * New native configurations
3429 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3430 FreeBSD/powerpc powerpc*-*-freebsd
3431 x86_64/Cygwin x86_64-*-cygwin*
3432 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3436 ARM AArch64 aarch64*-*-elf
3437 ARM AArch64 GNU/Linux aarch64*-*-linux
3438 Lynx 178 PowerPC powerpc-*-lynx*178
3439 x86_64/Cygwin x86_64-*-cygwin*
3440 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3442 * If the configured location of system.gdbinit file (as given by the
3443 --with-system-gdbinit option at configure time) is in the
3444 data-directory (as specified by --with-gdb-datadir at configure
3445 time) or in one of its subdirectories, then GDB will look for the
3446 system-wide init file in the directory specified by the
3447 --data-directory command-line option.
3449 * New command line options:
3451 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3452 other initialization files, unlike -nx which disables all of them.
3454 * Removed command line options
3456 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3459 * The 'ptype' and 'whatis' commands now accept an argument to control
3462 * 'info proc' now works on some core files.
3466 ** Vectors can be created with gdb.Type.vector.
3468 ** Python's atexit.register now works in GDB.
3470 ** Types can be pretty-printed via a Python API.
3472 ** Python 3 is now supported (in addition to Python 2.4 or later)
3474 ** New class gdb.Architecture exposes GDB's internal representation
3475 of architecture in the Python API.
3477 ** New method Frame.architecture returns the gdb.Architecture object
3478 corresponding to the frame's architecture.
3480 * New Python-based convenience functions:
3482 ** $_memeq(buf1, buf2, length)
3483 ** $_streq(str1, str2)
3485 ** $_regex(str, regex)
3487 * The 'cd' command now defaults to using '~' (the home directory) if not
3490 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3491 default for GCC since November 2000.
3493 * The command 'forward-search' can now be abbreviated as 'fo'.
3495 * The command 'info tracepoints' can now display 'installed on target'
3496 or 'not installed on target' for each non-pending location of tracepoint.
3498 * New configure options
3500 --enable-libmcheck/--disable-libmcheck
3501 By default, development versions are built with -lmcheck on hosts
3502 that support it, in order to help track memory corruption issues.
3503 Release versions, on the other hand, are built without -lmcheck
3504 by default. The --enable-libmcheck/--disable-libmcheck configure
3505 options allow the user to override that default.
3506 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3507 This configure option allows the user to build GDB with
3508 libbabeltrace using which GDB can read Common Trace Format data.
3510 * New commands (for set/show, see "New options" below)
3513 Catch signals. This is similar to "handle", but allows commands and
3514 conditions to be attached.
3517 List the BFDs known to GDB.
3519 python-interactive [command]
3521 Start a Python interactive prompt, or evaluate the optional command
3522 and print the result of expressions.
3525 "py" is a new alias for "python".
3527 enable type-printer [name]...
3528 disable type-printer [name]...
3529 Enable or disable type printers.
3533 ** For the Renesas Super-H architecture, the "regs" command has been removed
3534 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3539 set print type methods (on|off)
3540 show print type methods
3541 Control whether method declarations are displayed by "ptype".
3542 The default is to show them.
3544 set print type typedefs (on|off)
3545 show print type typedefs
3546 Control whether typedef definitions are displayed by "ptype".
3547 The default is to show them.
3549 set filename-display basename|relative|absolute
3550 show filename-display
3551 Control the way in which filenames is displayed.
3552 The default is "relative", which preserves previous behavior.
3554 set trace-buffer-size
3555 show trace-buffer-size
3556 Request target to change the size of trace buffer.
3558 set remote trace-buffer-size-packet auto|on|off
3559 show remote trace-buffer-size-packet
3560 Control the use of the remote protocol `QTBuffer:size' packet.
3564 Control display of debugging messages related to ARM AArch64.
3567 set debug coff-pe-read
3568 show debug coff-pe-read
3569 Control display of debugging messages related to reading of COFF/PE
3574 Control display of debugging messages related to Mach-O symbols
3577 set debug notification
3578 show debug notification
3579 Control display of debugging info for async remote notification.
3583 ** Command parameter changes are now notified using new async record
3584 "=cmd-param-changed".
3585 ** Trace frame changes caused by command "tfind" are now notified using
3586 new async record "=traceframe-changed".
3587 ** The creation, deletion and modification of trace state variables
3588 are now notified using new async records "=tsv-created",
3589 "=tsv-deleted" and "=tsv-modified".
3590 ** The start and stop of process record are now notified using new
3591 async record "=record-started" and "=record-stopped".
3592 ** Memory changes are now notified using new async record
3594 ** The data-disassemble command response will include a "fullname" field
3595 containing the absolute file name when source has been requested.
3596 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3597 command, to allow pattern filling of memory areas.
3598 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3599 library load/unload events.
3600 ** The response to breakpoint commands and breakpoint async records
3601 includes an "installed" field containing a boolean state about each
3602 non-pending tracepoint location is whether installed on target or not.
3603 ** Output of the "-trace-status" command includes a "trace-file" field
3604 containing the name of the trace file being examined. This field is
3605 optional, and only present when examining a trace file.
3606 ** The "fullname" field is now always present along with the "file" field,
3607 even if the file cannot be found by GDB.
3609 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3610 You must have the LZMA library available when configuring GDB for this
3611 feature to be enabled. For more information, see:
3612 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3614 * New remote packets
3617 Set the size of trace buffer. The remote stub reports support for this
3618 packet to gdb's qSupported query.
3621 Enable Branch Trace Store (BTS)-based branch tracing for the current
3622 thread. The remote stub reports support for this packet to gdb's
3626 Disable branch tracing for the current thread. The remote stub reports
3627 support for this packet to gdb's qSupported query.
3630 Read the traced branches for the current thread. The remote stub
3631 reports support for this packet to gdb's qSupported query.
3633 *** Changes in GDB 7.5
3635 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3636 for more x32 ABI info.
3638 * GDB now supports access to MIPS DSP registers on Linux targets.
3640 * GDB now supports debugging microMIPS binaries.
3642 * The "info os" command on GNU/Linux can now display information on
3643 several new classes of objects managed by the operating system:
3644 "info os procgroups" lists process groups
3645 "info os files" lists file descriptors
3646 "info os sockets" lists internet-domain sockets
3647 "info os shm" lists shared-memory regions
3648 "info os semaphores" lists semaphores
3649 "info os msg" lists message queues
3650 "info os modules" lists loaded kernel modules
3652 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3653 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3654 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3655 options and inspect the probe arguments using the new $_probe_arg family
3656 of convenience variables. You can obtain more information about SystemTap
3657 in <http://sourceware.org/systemtap/>.
3659 * GDB now supports reversible debugging on ARM, it allows you to
3660 debug basic ARM and THUMB instructions, and provides
3661 record/replay support.
3663 * The option "symbol-reloading" has been deleted as it is no longer used.
3667 ** GDB commands implemented in Python can now be put in command class
3670 ** The "maint set python print-stack on|off" is now deleted.
3672 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3673 apply "flag enum"-style pretty-printing to any enum.
3675 ** gdb.lookup_symbol can now work when there is no current frame.
3677 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3678 the source at which the symbol was defined.
3680 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3681 method 'value'. The former indicates whether the symbol needs a
3682 frame in order to compute its value, and the latter computes the
3685 ** A new method 'referenced_value' on gdb.Value objects which can
3686 dereference pointer as well as C++ reference values.
3688 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3689 which return the global and static blocks (as gdb.Block objects),
3690 of the underlying symbol table, respectively.
3692 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3693 object associated with a PC value.
3695 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3696 of the address range occupied by code for the current source line.
3698 * Go language support.
3699 GDB now supports debugging programs written in the Go programming
3702 * GDBserver now supports stdio connections.
3703 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3705 * The binary "gdbtui" can no longer be built or installed.
3706 Use "gdb -tui" instead.
3708 * GDB will now print "flag" enums specially. A flag enum is one where
3709 all the enumerator values have no bits in common when pairwise
3710 "and"ed. When printing a value whose type is a flag enum, GDB will
3711 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3712 (gdb) print (enum E) 3
3715 * The filename part of a linespec will now match trailing components
3716 of a source file name. For example, "break gcc/expr.c:1000" will
3717 now set a breakpoint in build/gcc/expr.c, but not
3718 build/libcpp/expr.c.
3720 * The "info proc" and "generate-core-file" commands will now also
3721 work on remote targets connected to GDBserver on Linux.
3723 * The command "info catch" has been removed. It has been disabled
3724 since December 2007.
3726 * The "catch exception" and "catch assert" commands now accept
3727 a condition at the end of the command, much like the "break"
3728 command does. For instance:
3730 (gdb) catch exception Constraint_Error if Barrier = True
3732 Previously, it was possible to add a condition to such catchpoints,
3733 but it had to be done as a second step, after the catchpoint had been
3734 created, using the "condition" command.
3736 * The "info static-tracepoint-marker" command will now also work on
3737 native Linux targets with in-process agent.
3739 * GDB can now set breakpoints on inlined functions.
3741 * The .gdb_index section has been updated to include symbols for
3742 inlined functions. GDB will ignore older .gdb_index sections by
3743 default, which could cause symbol files to be loaded more slowly
3744 until their .gdb_index sections can be recreated. The new command
3745 "set use-deprecated-index-sections on" will cause GDB to use any older
3746 .gdb_index sections it finds. This will restore performance, but the
3747 ability to set breakpoints on inlined functions will be lost in symbol
3748 files with older .gdb_index sections.
3750 The .gdb_index section has also been updated to record more information
3751 about each symbol. This speeds up the "info variables", "info functions"
3752 and "info types" commands when used with programs having the .gdb_index
3753 section, as well as speeding up debugging with shared libraries using
3754 the .gdb_index section.
3756 * Ada support for GDB/MI Variable Objects has been added.
3758 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3763 ** New command -info-os is the MI equivalent of "info os".
3765 ** Output logs ("set logging" and related) now include MI output.
3769 ** "set use-deprecated-index-sections on|off"
3770 "show use-deprecated-index-sections on|off"
3771 Controls the use of deprecated .gdb_index sections.
3773 ** "catch load" and "catch unload" can be used to stop when a shared
3774 library is loaded or unloaded, respectively.
3776 ** "enable count" can be used to auto-disable a breakpoint after
3779 ** "info vtbl" can be used to show the virtual method tables for
3780 C++ and Java objects.
3782 ** "explore" and its sub commands "explore value" and "explore type"
3783 can be used to recursively explore values and types of
3784 expressions. These commands are available only if GDB is
3785 configured with '--with-python'.
3787 ** "info auto-load" shows status of all kinds of auto-loaded files,
3788 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3789 sequences of commands files, "info auto-load python-scripts"
3790 shows status of auto-loading Python script files,
3791 "info auto-load local-gdbinit" shows status of loading init file
3792 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3793 status of inferior specific thread debugging shared library loading.
3795 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3796 and "show auto-load-scripts" commands have been deprecated, use their
3797 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3798 and "show auto-load python-scripts" counterparts instead.
3800 ** "dprintf location,format,args..." creates a dynamic printf, which
3801 is basically a breakpoint that does a printf and immediately
3802 resumes your program's execution, so it is like a printf that you
3803 can insert dynamically at runtime instead of at compiletime.
3805 ** "set print symbol"
3807 Controls whether GDB attempts to display the symbol, if any,
3808 corresponding to addresses it prints. This defaults to "on", but
3809 you can set it to "off" to restore GDB's previous behavior.
3811 * Deprecated commands
3813 ** For the Renesas Super-H architecture, the "regs" command has been
3814 deprecated, and "info all-registers" should be used instead.
3818 Renesas RL78 rl78-*-elf
3819 HP OpenVMS ia64 ia64-hp-openvms*
3821 * GDBserver supports evaluation of breakpoint conditions. When
3822 support is advertised by GDBserver, GDB may be told to send the
3823 breakpoint conditions in bytecode form to GDBserver. GDBserver
3824 will only report the breakpoint trigger to GDB when its condition
3829 set mips compression
3830 show mips compression
3831 Select the compressed ISA encoding used in functions that have no symbol
3832 information available. The encoding can be set to either of:
3835 and is updated automatically from ELF file flags if available.
3837 set breakpoint condition-evaluation
3838 show breakpoint condition-evaluation
3839 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3840 GDBserver ("target"). Default option "auto" chooses the most efficient
3842 This option can improve debugger efficiency depending on the speed of the
3846 Disable auto-loading globally.
3849 Show auto-loading setting of all kinds of auto-loaded files.
3851 set auto-load gdb-scripts on|off
3852 show auto-load gdb-scripts
3853 Control auto-loading of GDB canned sequences of commands files.
3855 set auto-load python-scripts on|off
3856 show auto-load python-scripts
3857 Control auto-loading of Python script files.
3859 set auto-load local-gdbinit on|off
3860 show auto-load local-gdbinit
3861 Control loading of init file (.gdbinit) from current directory.
3863 set auto-load libthread-db on|off
3864 show auto-load libthread-db
3865 Control auto-loading of inferior specific thread debugging shared library.
3867 set auto-load scripts-directory <dir1>[:<dir2>...]
3868 show auto-load scripts-directory
3869 Set a list of directories from which to load auto-loaded scripts.
3870 Automatically loaded Python scripts and GDB scripts are located in one
3871 of the directories listed by this option.
3872 The delimiter (':' above) may differ according to the host platform.
3874 set auto-load safe-path <dir1>[:<dir2>...]
3875 show auto-load safe-path
3876 Set a list of directories from which it is safe to auto-load files.
3877 The delimiter (':' above) may differ according to the host platform.
3879 set debug auto-load on|off
3880 show debug auto-load
3881 Control display of debugging info for auto-loading the files above.
3883 set dprintf-style gdb|call|agent
3885 Control the way in which a dynamic printf is performed; "gdb"
3886 requests a GDB printf command, while "call" causes dprintf to call a
3887 function in the inferior. "agent" requests that the target agent
3888 (such as GDBserver) do the printing.
3890 set dprintf-function <expr>
3891 show dprintf-function
3892 set dprintf-channel <expr>
3893 show dprintf-channel
3894 Set the function and optional first argument to the call when using
3895 the "call" style of dynamic printf.
3897 set disconnected-dprintf on|off
3898 show disconnected-dprintf
3899 Control whether agent-style dynamic printfs continue to be in effect
3900 after GDB disconnects.
3902 * New configure options
3904 --with-auto-load-dir
3905 Configure default value for the 'set auto-load scripts-directory'
3906 setting above. It defaults to '$debugdir:$datadir/auto-load',
3907 $debugdir representing global debugging info directories (available
3908 via 'show debug-file-directory') and $datadir representing GDB's data
3909 directory (available via 'show data-directory').
3911 --with-auto-load-safe-path
3912 Configure default value for the 'set auto-load safe-path' setting
3913 above. It defaults to the --with-auto-load-dir setting.
3915 --without-auto-load-safe-path
3916 Set 'set auto-load safe-path' to '/', effectively disabling this
3919 * New remote packets
3921 z0/z1 conditional breakpoints extension
3923 The z0/z1 breakpoint insertion packets have been extended to carry
3924 a list of conditional expressions over to the remote stub depending on the
3925 condition evaluation mode. The use of this extension can be controlled
3926 via the "set remote conditional-breakpoints-packet" command.
3930 Specify the signals which the remote stub may pass to the debugged
3931 program without GDB involvement.
3933 * New command line options
3935 --init-command=FILE, -ix Like --command, -x but execute it
3936 before loading inferior.
3937 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3938 execute it before loading inferior.
3940 *** Changes in GDB 7.4
3942 * GDB now handles ambiguous linespecs more consistently; the existing
3943 FILE:LINE support has been expanded to other types of linespecs. A
3944 breakpoint will now be set on all matching locations in all
3945 inferiors, and locations will be added or removed according to
3948 * GDB now allows you to skip uninteresting functions and files when
3949 stepping with the "skip function" and "skip file" commands.
3951 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3952 and "show remote hardware-watchpoint-length-limit". These allows to
3953 set or show the maximum length limit (in bytes) of a remote
3954 target hardware watchpoint.
3956 This allows e.g. to use "unlimited" hardware watchpoints with the
3957 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3958 watchpoints are slower than real hardware watchpoints but are
3959 significantly faster than gdb software watchpoints.
3963 ** The register_pretty_printer function in module gdb.printing now takes
3964 an optional `replace' argument. If True, the new printer replaces any
3967 ** The "maint set python print-stack on|off" command has been
3968 deprecated and will be deleted in GDB 7.5.
3969 A new command: "set python print-stack none|full|message" has
3970 replaced it. Additionally, the default for "print-stack" is
3971 now "message", which just prints the error message without
3974 ** A prompt substitution hook (prompt_hook) is now available to the
3977 ** A new Python module, gdb.prompt has been added to the GDB Python
3978 modules library. This module provides functionality for
3979 escape sequences in prompts (used by set/show
3980 extended-prompt). These escape sequences are replaced by their
3981 corresponding value.
3983 ** Python commands and convenience-functions located in
3984 'data-directory'/python/gdb/command and
3985 'data-directory'/python/gdb/function are now automatically loaded
3988 ** Blocks now provide four new attributes. global_block and
3989 static_block will return the global and static blocks
3990 respectively. is_static and is_global are boolean attributes
3991 that indicate if the block is one of those two types.
3993 ** Symbols now provide the "type" attribute, the type of the symbol.
3995 ** The "gdb.breakpoint" function has been deprecated in favor of
3998 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3999 of a function. This class is based on the "finish" command
4000 available in the CLI.
4002 ** Type objects for struct and union types now allow access to
4003 the fields using standard Python dictionary (mapping) methods.
4004 For example, "some_type['myfield']" now works, as does
4005 "some_type.items()".
4007 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4010 ** A new function, "deep_items" has been added to the gdb.types
4011 module in the GDB Python modules library. This function returns
4012 an iterator over the fields of a struct or union type. Unlike
4013 the standard Python "iteritems" method, it will recursively traverse
4014 any anonymous fields.
4018 ** "*stopped" events can report several new "reason"s, such as
4021 ** Breakpoint changes are now notified using new async records, like
4022 "=breakpoint-modified".
4024 ** New command -ada-task-info.
4026 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4027 $sdir specifies the default system locations of shared libraries.
4028 $pdir specifies the directory where the libpthread used by the application
4031 GDB no longer looks in $sdir and $pdir after it has searched the directories
4032 mentioned in libthread-db-search-path. If you want to search those
4033 directories, they must be specified in libthread-db-search-path.
4034 The default value of libthread-db-search-path on GNU/Linux and Solaris
4035 systems is now "$sdir:$pdir".
4037 $pdir is not supported by gdbserver, it is currently ignored.
4038 $sdir is supported by gdbserver.
4040 * New configure option --with-iconv-bin.
4041 When using the internationalization support like the one in the GNU C
4042 library, GDB will invoke the "iconv" program to get a list of supported
4043 character sets. If this program lives in a non-standard location, one can
4044 use this option to specify where to find it.
4046 * When natively debugging programs on PowerPC BookE processors running
4047 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4048 watchpoints, which specify a mask in addition to an address to watch.
4049 The mask specifies that some bits of an address (the bits which are
4050 reset in the mask) should be ignored when matching the address accessed
4051 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4052 section in the user manual for more details.
4054 * The new option --once causes GDBserver to stop listening for connections once
4055 the first connection is made. The listening port used by GDBserver will
4056 become available after that.
4058 * New commands "info macros" and "alias" have been added.
4060 * New function parameters suffix @entry specifies value of function parameter
4061 at the time the function got called. Entry values are available only since
4067 "!" is now an alias of the "shell" command.
4068 Note that no space is needed between "!" and SHELL COMMAND.
4072 watch EXPRESSION mask MASK_VALUE
4073 The watch command now supports the mask argument which allows creation
4074 of masked watchpoints, if the current architecture supports this feature.
4076 info auto-load-scripts [REGEXP]
4077 This command was formerly named "maintenance print section-scripts".
4078 It is now generally useful and is no longer a maintenance-only command.
4080 info macro [-all] [--] MACRO
4081 The info macro command has new options `-all' and `--'. The first for
4082 printing all definitions of a macro. The second for explicitly specifying
4083 the end of arguments and the beginning of the macro name in case the macro
4084 name starts with a hyphen.
4086 collect[/s] EXPRESSIONS
4087 The tracepoint collect command now takes an optional modifier "/s"
4088 that directs it to dereference pointer-to-character types and
4089 collect the bytes of memory up to a zero byte. The behavior is
4090 similar to what you see when you use the regular print command on a
4091 string. An optional integer following the "/s" sets a bound on the
4092 number of bytes that will be collected.
4095 The trace start command now interprets any supplied arguments as a
4096 note to be recorded with the trace run, with an effect similar to
4097 setting the variable trace-notes.
4100 The trace stop command now interprets any arguments as a note to be
4101 mentioned along with the tstatus report that the trace was stopped
4102 with a command. The effect is similar to setting the variable
4105 * Tracepoints can now be enabled and disabled at any time after a trace
4106 experiment has been started using the standard "enable" and "disable"
4107 commands. It is now possible to start a trace experiment with no enabled
4108 tracepoints; GDB will display a warning, but will allow the experiment to
4109 begin, assuming that tracepoints will be enabled as needed while the trace
4112 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4113 locations with 4-byte instructions, when they were previously
4114 limited to locations with instructions of 5 bytes or longer.
4118 set debug dwarf2-read
4119 show debug dwarf2-read
4120 Turns on or off display of debugging messages related to reading
4121 DWARF debug info. The default is off.
4123 set debug symtab-create
4124 show debug symtab-create
4125 Turns on or off display of debugging messages related to symbol table
4126 creation. The default is off.
4129 show extended-prompt
4130 Set the GDB prompt, and allow escape sequences to be inserted to
4131 display miscellaneous information (see 'help set extended-prompt'
4132 for the list of sequences). This prompt (and any information
4133 accessed through the escape sequences) is updated every time the
4134 prompt is displayed.
4136 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4137 show print entry-values
4138 Set printing of frame argument values at function entry. In some cases
4139 GDB can determine the value of function argument which was passed by the
4140 function caller, even if the value was modified inside the called function.
4142 set debug entry-values
4143 show debug entry-values
4144 Control display of debugging info for determining frame argument values at
4145 function entry and virtual tail call frames.
4147 set basenames-may-differ
4148 show basenames-may-differ
4149 Set whether a source file may have multiple base names.
4150 (A "base name" is the name of a file with the directory part removed.
4151 Example: The base name of "/home/user/hello.c" is "hello.c".)
4152 If set, GDB will canonicalize file names (e.g., expand symlinks)
4153 before comparing them. Canonicalization is an expensive operation,
4154 but it allows the same file be known by more than one base name.
4155 If not set (the default), all source files are assumed to have just
4156 one base name, and gdb will do file name comparisons more efficiently.
4162 Set a user name and notes for the current and any future trace runs.
4163 This is useful for long-running and/or disconnected traces, to
4164 inform others (or yourself) as to who is running the trace, supply
4165 contact information, or otherwise explain what is going on.
4167 set trace-stop-notes
4168 show trace-stop-notes
4169 Set a note attached to the trace run, that is displayed when the
4170 trace has been stopped by a tstop command. This is useful for
4171 instance as an explanation, if you are stopping a trace run that was
4172 started by someone else.
4174 * New remote packets
4178 Dynamically enable a tracepoint in a started trace experiment.
4182 Dynamically disable a tracepoint in a started trace experiment.
4186 Set the user and notes of the trace run.
4190 Query the current status of a tracepoint.
4194 Query the minimum length of instruction at which a fast tracepoint may
4197 * Dcache size (number of lines) and line-size are now runtime-configurable
4198 via "set dcache line" and "set dcache line-size" commands.
4202 Texas Instruments TMS320C6x tic6x-*-*
4206 Renesas RL78 rl78-*-elf
4208 *** Changes in GDB 7.3.1
4210 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4212 *** Changes in GDB 7.3
4214 * GDB has a new command: "thread find [REGEXP]".
4215 It finds the thread id whose name, target id, or thread extra info
4216 matches the given regular expression.
4218 * The "catch syscall" command now works on mips*-linux* targets.
4220 * The -data-disassemble MI command now supports modes 2 and 3 for
4221 dumping the instruction opcodes.
4223 * New command line options
4225 -data-directory DIR Specify DIR as the "data-directory".
4226 This is mostly for testing purposes.
4228 * The "maint set python auto-load on|off" command has been renamed to
4229 "set auto-load-scripts on|off".
4231 * GDB has a new command: "set directories".
4232 It is like the "dir" command except that it replaces the
4233 source path list instead of augmenting it.
4235 * GDB now understands thread names.
4237 On GNU/Linux, "info threads" will display the thread name as set by
4238 prctl or pthread_setname_np.
4240 There is also a new command, "thread name", which can be used to
4241 assign a name internally for GDB to display.
4244 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4245 has been integrated into GDB.
4249 ** The function gdb.Write now accepts an optional keyword 'stream'.
4250 This keyword, when provided, will direct the output to either
4251 stdout, stderr, or GDB's logging output.
4253 ** Parameters can now be be sub-classed in Python, and in particular
4254 you may implement the get_set_doc and get_show_doc functions.
4255 This improves how Parameter set/show documentation is processed
4256 and allows for more dynamic content.
4258 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4259 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4260 have an is_valid method.
4262 ** Breakpoints can now be sub-classed in Python, and in particular
4263 you may implement a 'stop' function that is executed each time
4264 the inferior reaches that breakpoint.
4266 ** New function gdb.lookup_global_symbol looks up a global symbol.
4268 ** GDB values in Python are now callable if the value represents a
4269 function. For example, if 'some_value' represents a function that
4270 takes two integer parameters and returns a value, you can call
4271 that function like so:
4273 result = some_value (10,20)
4275 ** Module gdb.types has been added.
4276 It contains a collection of utilities for working with gdb.Types objects:
4277 get_basic_type, has_field, make_enum_dict.
4279 ** Module gdb.printing has been added.
4280 It contains utilities for writing and registering pretty-printers.
4281 New classes: PrettyPrinter, SubPrettyPrinter,
4282 RegexpCollectionPrettyPrinter.
4283 New function: register_pretty_printer.
4285 ** New commands "info pretty-printers", "enable pretty-printer" and
4286 "disable pretty-printer" have been added.
4288 ** gdb.parameter("directories") is now available.
4290 ** New function gdb.newest_frame returns the newest frame in the
4293 ** The gdb.InferiorThread class has a new "name" attribute. This
4294 holds the thread's name.
4296 ** Python Support for Inferior events.
4297 Python scripts can add observers to be notified of events
4298 occurring in the process being debugged.
4299 The following events are currently supported:
4300 - gdb.events.cont Continue event.
4301 - gdb.events.exited Inferior exited event.
4302 - gdb.events.stop Signal received, and Breakpoint hit events.
4306 ** GDB now puts template parameters in scope when debugging in an
4307 instantiation. For example, if you have:
4309 template<int X> int func (void) { return X; }
4311 then if you step into func<5>, "print X" will show "5". This
4312 feature requires proper debuginfo support from the compiler; it
4313 was added to GCC 4.5.
4315 ** The motion commands "next", "finish", "until", and "advance" now
4316 work better when exceptions are thrown. In particular, GDB will
4317 no longer lose control of the inferior; instead, the GDB will
4318 stop the inferior at the point at which the exception is caught.
4319 This functionality requires a change in the exception handling
4320 code that was introduced in GCC 4.5.
4322 * GDB now follows GCC's rules on accessing volatile objects when
4323 reading or writing target state during expression evaluation.
4324 One notable difference to prior behavior is that "print x = 0"
4325 no longer generates a read of x; the value of the assignment is
4326 now always taken directly from the value being assigned.
4328 * GDB now has some support for using labels in the program's source in
4329 linespecs. For instance, you can use "advance label" to continue
4330 execution to a label.
4332 * GDB now has support for reading and writing a new .gdb_index
4333 section. This section holds a fast index of DWARF debugging
4334 information and can be used to greatly speed up GDB startup and
4335 operation. See the documentation for `save gdb-index' for details.
4337 * The "watch" command now accepts an optional "-location" argument.
4338 When used, this causes GDB to watch the memory referred to by the
4339 expression. Such a watchpoint is never deleted due to it going out
4342 * GDB now supports thread debugging of core dumps on GNU/Linux.
4344 GDB now activates thread debugging using the libthread_db library
4345 when debugging GNU/Linux core dumps, similarly to when debugging
4346 live processes. As a result, when debugging a core dump file, GDB
4347 is now able to display pthread_t ids of threads. For example, "info
4348 threads" shows the same output as when debugging the process when it
4349 was live. In earlier releases, you'd see something like this:
4352 * 1 LWP 6780 main () at main.c:10
4354 While now you see this:
4357 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4359 It is also now possible to inspect TLS variables when debugging core
4362 When debugging a core dump generated on a machine other than the one
4363 used to run GDB, you may need to point GDB at the correct
4364 libthread_db library with the "set libthread-db-search-path"
4365 command. See the user manual for more details on this command.
4367 * When natively debugging programs on PowerPC BookE processors running
4368 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4369 which stop execution of the inferior whenever it executes an instruction
4370 at any address within the specified range. See the "PowerPC Embedded"
4371 section in the user manual for more details.
4373 * New features in the GDB remote stub, GDBserver
4375 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4376 and i686 LynxOS (version 5.x).
4378 ** GDBserver is now supported on Blackfin Linux.
4380 * New native configurations
4382 ia64 HP-UX ia64-*-hpux*
4386 Analog Devices, Inc. Blackfin Processor bfin-*
4388 * Ada task switching is now supported on sparc-elf targets when
4389 debugging a program using the Ravenscar Profile. For more information,
4390 see the "Tasking Support when using the Ravenscar Profile" section
4391 in the GDB user manual.
4393 * Guile support was removed.
4395 * New features in the GNU simulator
4397 ** The --map-info flag lists all known core mappings.
4399 ** CFI flashes may be simulated via the "cfi" device.
4401 *** Changes in GDB 7.2
4403 * Shared library support for remote targets by default
4405 When GDB is configured for a generic, non-OS specific target, like
4406 for example, --target=arm-eabi or one of the many *-*-elf targets,
4407 GDB now queries remote stubs for loaded shared libraries using the
4408 `qXfer:libraries:read' packet. Previously, shared library support
4409 was always disabled for such configurations.
4413 ** Argument Dependent Lookup (ADL)
4415 In C++ ADL lookup directs function search to the namespaces of its
4416 arguments even if the namespace has not been imported.
4426 Here the compiler will search for `foo' in the namespace of 'b'
4427 and find A::foo. GDB now supports this. This construct is commonly
4428 used in the Standard Template Library for operators.
4430 ** Improved User Defined Operator Support
4432 In addition to member operators, GDB now supports lookup of operators
4433 defined in a namespace and imported with a `using' directive, operators
4434 defined in the global scope, operators imported implicitly from an
4435 anonymous namespace, and the ADL operators mentioned in the previous
4437 GDB now also supports proper overload resolution for all the previously
4438 mentioned flavors of operators.
4440 ** static const class members
4442 Printing of static const class members that are initialized in the
4443 class definition has been fixed.
4445 * Windows Thread Information Block access.
4447 On Windows targets, GDB now supports displaying the Windows Thread
4448 Information Block (TIB) structure. This structure is visible either
4449 by using the new command `info w32 thread-information-block' or, by
4450 dereferencing the new convenience variable named `$_tlb', a
4451 thread-specific pointer to the TIB. This feature is also supported
4452 when remote debugging using GDBserver.
4454 * Static tracepoints
4456 Static tracepoints are calls in the user program into a tracing
4457 library. One such library is a port of the LTTng kernel tracer to
4458 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4459 When debugging with GDBserver, GDB now supports combining the GDB
4460 tracepoint machinery with such libraries. For example: the user can
4461 use GDB to probe a static tracepoint marker (a call from the user
4462 program into the tracing library) with the new "strace" command (see
4463 "New commands" below). This creates a "static tracepoint" in the
4464 breakpoint list, that can be manipulated with the same feature set
4465 as fast and regular tracepoints. E.g., collect registers, local and
4466 global variables, collect trace state variables, and define
4467 tracepoint conditions. In addition, the user can collect extra
4468 static tracepoint marker specific data, by collecting the new
4469 $_sdata internal variable. When analyzing the trace buffer, you can
4470 inspect $_sdata like any other variable available to GDB. For more
4471 information, see the "Tracepoints" chapter in GDB user manual. New
4472 remote packets have been defined to support static tracepoints, see
4473 the "New remote packets" section below.
4475 * Better reconstruction of tracepoints after disconnected tracing
4477 GDB will attempt to download the original source form of tracepoint
4478 definitions when starting a trace run, and then will upload these
4479 upon reconnection to the target, resulting in a more accurate
4480 reconstruction of the tracepoints that are in use on the target.
4484 You can now exercise direct control over the ways that GDB can
4485 affect your program. For instance, you can disallow the setting of
4486 breakpoints, so that the program can run continuously (assuming
4487 non-stop mode). In addition, the "observer" variable is available
4488 to switch all of the different controls; in observer mode, GDB
4489 cannot affect the target's behavior at all, which is useful for
4490 tasks like diagnosing live systems in the field.
4492 * The new convenience variable $_thread holds the number of the
4495 * New remote packets
4499 Return the address of the Windows Thread Information Block of a given thread.
4503 In response to several of the tracepoint packets, the target may now
4504 also respond with a number of intermediate `qRelocInsn' request
4505 packets before the final result packet, to have GDB handle
4506 relocating an instruction to execute at a different address. This
4507 is particularly useful for stubs that support fast tracepoints. GDB
4508 reports support for this feature in the qSupported packet.
4512 List static tracepoint markers in the target program.
4516 List static tracepoint markers at a given address in the target
4519 qXfer:statictrace:read
4521 Read the static trace data collected (by a `collect $_sdata'
4522 tracepoint action). The remote stub reports support for this packet
4523 to gdb's qSupported query.
4527 Send the current settings of GDB's permission flags.
4531 Send part of the source (textual) form of a tracepoint definition,
4532 which includes location, conditional, and action list.
4534 * The source command now accepts a -s option to force searching for the
4535 script in the source search path even if the script name specifies
4538 * New features in the GDB remote stub, GDBserver
4540 - GDBserver now support tracepoints (including fast tracepoints, and
4541 static tracepoints). The feature is currently supported by the
4542 i386-linux and amd64-linux builds. See the "Tracepoints support
4543 in gdbserver" section in the manual for more information.
4545 GDBserver JIT compiles the tracepoint's conditional agent
4546 expression bytecode into native code whenever possible for low
4547 overhead dynamic tracepoints conditionals. For such tracepoints,
4548 an expression that examines program state is evaluated when the
4549 tracepoint is reached, in order to determine whether to capture
4550 trace data. If the condition is simple and false, processing the
4551 tracepoint finishes very quickly and no data is gathered.
4553 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4554 for static tracepoints support.
4556 - GDBserver now supports x86_64 Windows 64-bit debugging.
4558 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4559 it understands register description.
4561 * The --batch flag now disables pagination and queries.
4563 * X86 general purpose registers
4565 GDB now supports reading/writing byte, word and double-word x86
4566 general purpose registers directly. This means you can use, say,
4567 $ah or $ax to refer, respectively, to the byte register AH and
4568 16-bit word register AX that are actually portions of the 32-bit
4569 register EAX or 64-bit register RAX.
4571 * The `commands' command now accepts a range of breakpoints to modify.
4572 A plain `commands' following a command that creates multiple
4573 breakpoints affects all the breakpoints set by that command. This
4574 applies to breakpoints set by `rbreak', and also applies when a
4575 single `break' command creates multiple breakpoints (e.g.,
4576 breakpoints on overloaded c++ functions).
4578 * The `rbreak' command now accepts a filename specification as part of
4579 its argument, limiting the functions selected by the regex to those
4580 in the specified file.
4582 * Support for remote debugging Windows and SymbianOS shared libraries
4583 from Unix hosts has been improved. Non Windows GDB builds now can
4584 understand target reported file names that follow MS-DOS based file
4585 system semantics, such as file names that include drive letters and
4586 use the backslash character as directory separator. This makes it
4587 possible to transparently use the "set sysroot" and "set
4588 solib-search-path" on Unix hosts to point as host copies of the
4589 target's shared libraries. See the new command "set
4590 target-file-system-kind" described below, and the "Commands to
4591 specify files" section in the user manual for more information.
4595 eval template, expressions...
4596 Convert the values of one or more expressions under the control
4597 of the string template to a command line, and call it.
4599 set target-file-system-kind unix|dos-based|auto
4600 show target-file-system-kind
4601 Set or show the assumed file system kind for target reported file
4604 save breakpoints <filename>
4605 Save all current breakpoint definitions to a file suitable for use
4606 in a later debugging session. To read the saved breakpoint
4607 definitions, use the `source' command.
4609 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4612 info static-tracepoint-markers
4613 Display information about static tracepoint markers in the target.
4615 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4616 Define a static tracepoint by probing a marker at the given
4617 function, line, address, or marker ID.
4621 Enable and disable observer mode.
4623 set may-write-registers on|off
4624 set may-write-memory on|off
4625 set may-insert-breakpoints on|off
4626 set may-insert-tracepoints on|off
4627 set may-insert-fast-tracepoints on|off
4628 set may-interrupt on|off
4629 Set individual permissions for GDB effects on the target. Note that
4630 some of these settings can have undesirable or surprising
4631 consequences, particularly when changed in the middle of a session.
4632 For instance, disabling the writing of memory can prevent
4633 breakpoints from being inserted, cause single-stepping to fail, or
4634 even crash your program, if you disable after breakpoints have been
4635 inserted. However, GDB should not crash.
4637 set record memory-query on|off
4638 show record memory-query
4639 Control whether to stop the inferior if memory changes caused
4640 by an instruction cannot be recorded.
4645 The disassemble command now supports "start,+length" form of two arguments.
4649 ** GDB now provides a new directory location, called the python directory,
4650 where Python scripts written for GDB can be installed. The location
4651 of that directory is <data-directory>/python, where <data-directory>
4652 is the GDB data directory. For more details, see section `Scripting
4653 GDB using Python' in the manual.
4655 ** The GDB Python API now has access to breakpoints, symbols, symbol
4656 tables, program spaces, inferiors, threads and frame's code blocks.
4657 Additionally, GDB Parameters can now be created from the API, and
4658 manipulated via set/show in the CLI.
4660 ** New functions gdb.target_charset, gdb.target_wide_charset,
4661 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4663 ** New exception gdb.GdbError.
4665 ** Pretty-printers are now also looked up in the current program space.
4667 ** Pretty-printers can now be individually enabled and disabled.
4669 ** GDB now looks for names of Python scripts to auto-load in a
4670 special section named `.debug_gdb_scripts', in addition to looking
4671 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4673 * Tracepoint actions were unified with breakpoint commands. In particular,
4674 there are no longer differences in "info break" output for breakpoints and
4675 tracepoints and the "commands" command can be used for both tracepoints and
4676 regular breakpoints.
4680 ARM Symbian arm*-*-symbianelf*
4682 * D language support.
4683 GDB now supports debugging programs written in the D programming
4686 * GDB now supports the extended ptrace interface for PowerPC which is
4687 available since Linux kernel version 2.6.34. This automatically enables
4688 any hardware breakpoints and additional hardware watchpoints available in
4689 the processor. The old ptrace interface exposes just one hardware
4690 watchpoint and no hardware breakpoints.
4692 * GDB is now able to use the Data Value Compare (DVC) register available on
4693 embedded PowerPC processors to implement in hardware simple watchpoint
4694 conditions of the form:
4696 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4698 This works in native GDB running on Linux kernels with the extended ptrace
4699 interface mentioned above.
4701 *** Changes in GDB 7.1
4705 ** Namespace Support
4707 GDB now supports importing of namespaces in C++. This enables the
4708 user to inspect variables from imported namespaces. Support for
4709 namepace aliasing has also been added. So, if a namespace is
4710 aliased in the current scope (e.g. namepace C=A; ) the user can
4711 print variables using the alias (e.g. (gdb) print C::x).
4715 All known bugs relating to the printing of virtual base class were
4716 fixed. It is now possible to call overloaded static methods using a
4721 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4722 and reinterpret_cast<> are now handled by the C++ expression parser.
4726 Xilinx MicroBlaze microblaze-*-*
4731 Xilinx MicroBlaze microblaze
4734 * Multi-program debugging.
4736 GDB now has support for multi-program (a.k.a. multi-executable or
4737 multi-exec) debugging. This allows for debugging multiple inferiors
4738 simultaneously each running a different program under the same GDB
4739 session. See "Debugging Multiple Inferiors and Programs" in the
4740 manual for more information. This implied some user visible changes
4741 in the multi-inferior support. For example, "info inferiors" now
4742 lists inferiors that are not running yet or that have exited
4743 already. See also "New commands" and "New options" below.
4745 * New tracing features
4747 GDB's tracepoint facility now includes several new features:
4749 ** Trace state variables
4751 GDB tracepoints now include support for trace state variables, which
4752 are variables managed by the target agent during a tracing
4753 experiment. They are useful for tracepoints that trigger each
4754 other, so for instance one tracepoint can count hits in a variable,
4755 and then a second tracepoint has a condition that is true when the
4756 count reaches a particular value. Trace state variables share the
4757 $-syntax of GDB convenience variables, and can appear in both
4758 tracepoint actions and condition expressions. Use the "tvariable"
4759 command to create, and "info tvariables" to view; see "Trace State
4760 Variables" in the manual for more detail.
4764 GDB now includes an option for defining fast tracepoints, which
4765 targets may implement more efficiently, such as by installing a jump
4766 into the target agent rather than a trap instruction. The resulting
4767 speedup can be by two orders of magnitude or more, although the
4768 tradeoff is that some program locations on some target architectures
4769 might not allow fast tracepoint installation, for instance if the
4770 instruction to be replaced is shorter than the jump. To request a
4771 fast tracepoint, use the "ftrace" command, with syntax identical to
4772 the regular trace command.
4774 ** Disconnected tracing
4776 It is now possible to detach GDB from the target while it is running
4777 a trace experiment, then reconnect later to see how the experiment
4778 is going. In addition, a new variable disconnected-tracing lets you
4779 tell the target agent whether to continue running a trace if the
4780 connection is lost unexpectedly.
4784 GDB now has the ability to save the trace buffer into a file, and
4785 then use that file as a target, similarly to you can do with
4786 corefiles. You can select trace frames, print data that was
4787 collected in them, and use tstatus to display the state of the
4788 tracing run at the moment that it was saved. To create a trace
4789 file, use "tsave <filename>", and to use it, do "target tfile
4792 ** Circular trace buffer
4794 You can ask the target agent to handle the trace buffer as a
4795 circular buffer, discarding the oldest trace frames to make room for
4796 newer ones, by setting circular-trace-buffer to on. This feature may
4797 not be available for all target agents.
4802 The disassemble command, when invoked with two arguments, now requires
4803 the arguments to be comma-separated.
4806 The info variables command now displays variable definitions. Files
4807 which only declare a variable are not shown.
4810 The source command is now capable of sourcing Python scripts.
4811 This feature is dependent on the debugger being build with Python
4814 Related to this enhancement is also the introduction of a new command
4815 "set script-extension" (see below).
4817 * New commands (for set/show, see "New options" below)
4819 record save [<FILENAME>]
4820 Save a file (in core file format) containing the process record
4821 execution log for replay debugging at a later time.
4823 record restore <FILENAME>
4824 Restore the process record execution log that was saved at an
4825 earlier time, for replay debugging.
4827 add-inferior [-copies <N>] [-exec <FILENAME>]
4830 clone-inferior [-copies <N>] [ID]
4831 Make a new inferior ready to execute the same program another
4832 inferior has loaded.
4837 maint info program-spaces
4838 List the program spaces loaded into GDB.
4840 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4841 show remote interrupt-sequence
4842 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4843 as the sequence to the remote target in order to interrupt the execution.
4844 Ctrl-C is a default. Some system prefers BREAK which is high level of
4845 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4846 Magic SysRq g. It is BREAK signal and character 'g'.
4848 set remote interrupt-on-connect [on | off]
4849 show remote interrupt-on-connect
4850 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4851 remote target when gdb connects to it. This is needed when you debug
4854 set remotebreak [on | off]
4856 Deprecated. Use "set/show remote interrupt-sequence" instead.
4858 tvariable $NAME [ = EXP ]
4859 Create or modify a trace state variable.
4862 List trace state variables and their values.
4864 delete tvariable $NAME ...
4865 Delete one or more trace state variables.
4868 Evaluate the given expressions without collecting anything into the
4869 trace buffer. (Valid in tracepoint actions only.)
4871 ftrace FN / FILE:LINE / *ADDR
4872 Define a fast tracepoint at the given function, line, or address.
4874 * New expression syntax
4876 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4877 GDB now parses 0b101010 identically with 42.
4881 set follow-exec-mode new|same
4882 show follow-exec-mode
4883 Control whether GDB reuses the same inferior across an exec call or
4884 creates a new one. This is useful to be able to restart the old
4885 executable after the inferior having done an exec call.
4887 set default-collect EXPR, ...
4888 show default-collect
4889 Define a list of expressions to be collected at each tracepoint.
4890 This is a useful way to ensure essential items are not overlooked,
4891 such as registers or a critical global variable.
4893 set disconnected-tracing
4894 show disconnected-tracing
4895 If set to 1, the target is instructed to continue tracing if it
4896 loses its connection to GDB. If 0, the target is to stop tracing
4899 set circular-trace-buffer
4900 show circular-trace-buffer
4901 If set to on, the target is instructed to use a circular trace buffer
4902 and discard the oldest trace frames instead of stopping the trace due
4903 to a full trace buffer. If set to off, the trace stops when the buffer
4904 fills up. Some targets may not support this.
4906 set script-extension off|soft|strict
4907 show script-extension
4908 If set to "off", the debugger does not perform any script language
4909 recognition, and all sourced files are assumed to be GDB scripts.
4910 If set to "soft" (the default), files are sourced according to
4911 filename extension, falling back to GDB scripts if the first
4913 If set to "strict", files are sourced according to filename extension.
4915 set ada trust-PAD-over-XVS on|off
4916 show ada trust-PAD-over-XVS
4917 If off, activate a workaround against a bug in the debugging information
4918 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4919 the GCC sources for more information about the GNAT encoding and
4920 PAD types in particular). It is always safe to set this option to
4921 off, but this introduces a slight performance penalty. The default
4924 * Python API Improvements
4926 ** GDB provides the new class gdb.LazyString. This is useful in
4927 some pretty-printing cases. The new method gdb.Value.lazy_string
4928 provides a simple way to create objects of this type.
4930 ** The fields returned by gdb.Type.fields now have an
4931 `is_base_class' attribute.
4933 ** The new method gdb.Type.range returns the range of an array type.
4935 ** The new method gdb.parse_and_eval can be used to parse and
4936 evaluate an expression.
4938 * New remote packets
4941 Define a trace state variable.
4944 Get the current value of a trace state variable.
4947 Set desired tracing behavior upon disconnection.
4950 Set the trace buffer to be linear or circular.
4953 Get data about the tracepoints currently in use.
4957 Process record now works correctly with hardware watchpoints.
4959 Multiple bug fixes have been made to the mips-irix port, making it
4960 much more reliable. In particular:
4961 - Debugging threaded applications is now possible again. Previously,
4962 GDB would hang while starting the program, or while waiting for
4963 the program to stop at a breakpoint.
4964 - Attaching to a running process no longer hangs.
4965 - An error occurring while loading a core file has been fixed.
4966 - Changing the value of the PC register now works again. This fixes
4967 problems observed when using the "jump" command, or when calling
4968 a function from GDB, or even when assigning a new value to $pc.
4969 - With the "finish" and "return" commands, the return value for functions
4970 returning a small array is now correctly printed.
4971 - It is now possible to break on shared library code which gets executed
4972 during a shared library init phase (code executed while executing
4973 their .init section). Previously, the breakpoint would have no effect.
4974 - GDB is now able to backtrace through the signal handler for
4975 non-threaded programs.
4977 PIE (Position Independent Executable) programs debugging is now supported.
4978 This includes debugging execution of PIC (Position Independent Code) shared
4979 libraries although for that, it should be possible to run such libraries as an
4982 *** Changes in GDB 7.0
4984 * GDB now has an interface for JIT compilation. Applications that
4985 dynamically generate code can create symbol files in memory and register
4986 them with GDB. For users, the feature should work transparently, and
4987 for JIT developers, the interface is documented in the GDB manual in the
4988 "JIT Compilation Interface" chapter.
4990 * Tracepoints may now be conditional. The syntax is as for
4991 breakpoints; either an "if" clause appended to the "trace" command,
4992 or the "condition" command is available. GDB sends the condition to
4993 the target for evaluation using the same bytecode format as is used
4994 for tracepoint actions.
4996 * The disassemble command now supports: an optional /r modifier, print the
4997 raw instructions in hex as well as in symbolic form, and an optional /m
4998 modifier to print mixed source+assembly.
5000 * Process record and replay
5002 In a architecture environment that supports ``process record and
5003 replay'', ``process record and replay'' target can record a log of
5004 the process execution, and replay it with both forward and reverse
5007 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5008 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5009 set execution-direction {forward|reverse}, for targets that support
5012 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5013 feature is available with a native GDB running on kernel version
5016 * GDB now has support for multi-byte and wide character sets on the
5017 target. Strings whose character type is wchar_t, char16_t, or
5018 char32_t are now correctly printed. GDB supports wide- and unicode-
5019 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5020 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5021 `printf'. This feature requires iconv to work properly; if your
5022 system does not have a working iconv, GDB can use GNU libiconv. See
5023 the installation instructions for more information.
5025 * GDB now supports automatic retrieval of shared library files from
5026 remote targets. To use this feature, specify a system root that begins
5027 with the `remote:' prefix, either via the `set sysroot' command or via
5028 the `--with-sysroot' configure-time option.
5030 * "info sharedlibrary" now takes an optional regex of libraries to show,
5031 and it now reports if a shared library has no debugging information.
5033 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5034 now complete on file names.
5036 * When completing in expressions, gdb will attempt to limit
5037 completions to allowable structure or union fields, where appropriate.
5038 For instance, consider:
5040 # struct example { int f1; double f2; };
5041 # struct example variable;
5044 If the user types TAB at the end of this command line, the available
5045 completions will be "f1" and "f2".
5047 * Inlined functions are now supported. They show up in backtraces, and
5048 the "step", "next", and "finish" commands handle them automatically.
5050 * GDB now supports the token-splicing (##) and stringification (#)
5051 operators when expanding macros. It also supports variable-arity
5054 * GDB now supports inspecting extra signal information, exported by
5055 the new $_siginfo convenience variable. The feature is currently
5056 implemented on linux ARM, i386 and amd64.
5058 * GDB can now display the VFP floating point registers and NEON vector
5059 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5060 can provide these registers (requires Linux 2.6.30 or later). Remote
5061 and simulator targets may also provide them.
5063 * New remote packets
5066 Search memory for a sequence of bytes.
5069 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5070 operation over reliable transport links. Use of this packet is
5071 controlled by the `set remote noack-packet' command.
5074 Kill the process with the specified process ID. Use this in preference
5075 to `k' when multiprocess protocol extensions are supported.
5078 Obtains additional operating system information
5082 Read or write additional signal information.
5084 * Removed remote protocol undocumented extension
5086 An undocumented extension to the remote protocol's `S' stop reply
5087 packet that permitted the stub to pass a process id was removed.
5088 Remote servers should use the `T' stop reply packet instead.
5090 * GDB now supports multiple function calling conventions according to the
5091 DWARF-2 DW_AT_calling_convention function attribute.
5093 * The SH target utilizes the aforementioned change to distinguish between gcc
5094 and Renesas calling convention. It also adds the new CLI commands
5095 `set/show sh calling-convention'.
5097 * GDB can now read compressed debug sections, as produced by GNU gold
5098 with the --compress-debug-sections=zlib flag.
5100 * 64-bit core files are now supported on AIX.
5102 * Thread switching is now supported on Tru64.
5104 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5105 which will be allocated using malloc later in program execution.
5107 * The qXfer:libraries:read remote protocol packet now allows passing a
5108 list of section offsets.
5110 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5111 conditions handling signals delivered during attach or thread creation
5112 have also been fixed.
5114 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5115 From the user's standpoint, all unqualified instances of True and False
5116 are treated as the standard definitions, regardless of context.
5118 * GDB now parses C++ symbol and type names more flexibly. For
5121 template<typename T> class C { };
5124 GDB will now correctly handle all of:
5126 ptype C<char const *>
5127 ptype C<char const*>
5128 ptype C<const char *>
5129 ptype C<const char*>
5131 * New features in the GDB remote stub, gdbserver
5133 - The "--wrapper" command-line argument tells gdbserver to use a
5134 wrapper program to launch programs for debugging.
5136 - On PowerPC and S/390 targets, it is now possible to use a single
5137 gdbserver executable to debug both 32-bit and 64-bit programs.
5138 (This requires gdbserver itself to be built as a 64-bit executable.)
5140 - gdbserver uses the new noack protocol mode for TCP connections to
5141 reduce communications latency, if also supported and enabled in GDB.
5143 - Support for the sparc64-linux-gnu target is now included in
5146 - The amd64-linux build of gdbserver now supports debugging both
5147 32-bit and 64-bit programs.
5149 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5150 now support hardware watchpoints, and will use them automatically
5155 GDB now has support for scripting using Python. Whether this is
5156 available is determined at configure time.
5158 New GDB commands can now be written in Python.
5160 * Ada tasking support
5162 Ada tasks can now be inspected in GDB. The following commands have
5166 Print the list of Ada tasks.
5168 Print detailed information about task number N.
5170 Print the task number of the current task.
5172 Switch the context of debugging to task number N.
5174 * Support for user-defined prefixed commands. The "define" command can
5175 add new commands to existing prefixes, e.g. "target".
5177 * Multi-inferior, multi-process debugging.
5179 GDB now has generalized support for multi-inferior debugging. See
5180 "Debugging Multiple Inferiors" in the manual for more information.
5181 Although availability still depends on target support, the command
5182 set is more uniform now. The GNU/Linux specific multi-forks support
5183 has been migrated to this new framework. This implied some user
5184 visible changes; see "New commands" and also "Removed commands"
5187 * Target descriptions can now describe the target OS ABI. See the
5188 "Target Description Format" section in the user manual for more
5191 * Target descriptions can now describe "compatible" architectures
5192 to indicate that the target can execute applications for a different
5193 architecture in addition to those for the main target architecture.
5194 See the "Target Description Format" section in the user manual for
5197 * Multi-architecture debugging.
5199 GDB now includes general supports for debugging applications on
5200 hybrid systems that use more than one single processor architecture
5201 at the same time. Each such hybrid architecture still requires
5202 specific support to be added. The only hybrid architecture supported
5203 in this version of GDB is the Cell Broadband Engine.
5205 * GDB now supports integrated debugging of Cell/B.E. applications that
5206 use both the PPU and SPU architectures. To enable support for hybrid
5207 Cell/B.E. debugging, you need to configure GDB to support both the
5208 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5209 --enable-targets configure option.
5211 * Non-stop mode debugging.
5213 For some targets, GDB now supports an optional mode of operation in
5214 which you can examine stopped threads while other threads continue
5215 to execute freely. This is referred to as non-stop mode, with the
5216 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5217 section in the user manual for more information.
5219 To be able to support remote non-stop debugging, a remote stub needs
5220 to implement the non-stop mode remote protocol extensions, as
5221 described in the "Remote Non-Stop" section of the user manual. The
5222 GDB remote stub, gdbserver, has been adjusted to support these
5223 extensions on linux targets.
5225 * New commands (for set/show, see "New options" below)
5227 catch syscall [NAME(S) | NUMBER(S)]
5228 Catch system calls. Arguments, which should be names of system
5229 calls or their numbers, mean catch only those syscalls. Without
5230 arguments, every syscall will be caught. When the inferior issues
5231 any of the specified syscalls, GDB will stop and announce the system
5232 call, both when it is called and when its call returns. This
5233 feature is currently available with a native GDB running on the
5234 Linux Kernel, under the following architectures: x86, x86_64,
5235 PowerPC and PowerPC64.
5237 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5239 Search memory for a sequence of bytes.
5241 maint set python print-stack
5242 maint show python print-stack
5243 Show a stack trace when an error is encountered in a Python script.
5246 Invoke CODE by passing it to the Python interpreter.
5251 These allow macros to be defined, undefined, and listed
5255 Show operating system information about processes.
5258 List the inferiors currently under GDB's control.
5261 Switch focus to inferior number NUM.
5264 Detach from inferior number NUM.
5267 Kill inferior number NUM.
5271 set spu stop-on-load
5272 show spu stop-on-load
5273 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5275 set spu auto-flush-cache
5276 show spu auto-flush-cache
5277 Control whether to automatically flush the software-managed cache
5278 during Cell/B.E. debugging.
5280 set sh calling-convention
5281 show sh calling-convention
5282 Control the calling convention used when calling SH target functions.
5285 show debug timestamp
5286 Control display of timestamps with GDB debugging output.
5288 set disassemble-next-line
5289 show disassemble-next-line
5290 Control display of disassembled source lines or instructions when
5293 set remote noack-packet
5294 show remote noack-packet
5295 Set/show the use of remote protocol QStartNoAckMode packet. See above
5296 under "New remote packets."
5298 set remote query-attached-packet
5299 show remote query-attached-packet
5300 Control use of remote protocol `qAttached' (query-attached) packet.
5302 set remote read-siginfo-object
5303 show remote read-siginfo-object
5304 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5307 set remote write-siginfo-object
5308 show remote write-siginfo-object
5309 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5312 set remote reverse-continue
5313 show remote reverse-continue
5314 Control use of remote protocol 'bc' (reverse-continue) packet.
5316 set remote reverse-step
5317 show remote reverse-step
5318 Control use of remote protocol 'bs' (reverse-step) packet.
5320 set displaced-stepping
5321 show displaced-stepping
5322 Control displaced stepping mode. Displaced stepping is a way to
5323 single-step over breakpoints without removing them from the debuggee.
5324 Also known as "out-of-line single-stepping".
5327 show debug displaced
5328 Control display of debugging info for displaced stepping.
5330 maint set internal-error
5331 maint show internal-error
5332 Control what GDB does when an internal error is detected.
5334 maint set internal-warning
5335 maint show internal-warning
5336 Control what GDB does when an internal warning is detected.
5341 Use a wrapper program to launch programs for debugging.
5343 set multiple-symbols (all|ask|cancel)
5344 show multiple-symbols
5345 The value of this variable can be changed to adjust the debugger behavior
5346 when an expression or a breakpoint location contains an ambiguous symbol
5347 name (an overloaded function name, for instance).
5349 set breakpoint always-inserted
5350 show breakpoint always-inserted
5351 Keep breakpoints always inserted in the target, as opposed to inserting
5352 them when resuming the target, and removing them when the target stops.
5353 This option can improve debugger performance on slow remote targets.
5355 set arm fallback-mode (arm|thumb|auto)
5356 show arm fallback-mode
5357 set arm force-mode (arm|thumb|auto)
5359 These commands control how ARM GDB determines whether instructions
5360 are ARM or Thumb. The default for both settings is auto, which uses
5361 the current CPSR value for instructions without symbols; previous
5362 versions of GDB behaved as if "set arm fallback-mode arm".
5364 set arm unwind-secure-frames
5365 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5367 This can trigger security exceptions when unwinding exception stacks.
5369 set disable-randomization
5370 show disable-randomization
5371 Standalone programs run with the virtual address space randomization enabled
5372 by default on some platforms. This option keeps the addresses stable across
5373 multiple debugging sessions.
5377 Control whether other threads are stopped or not when some thread hits
5382 Requests that asynchronous execution is enabled in the target, if available.
5383 In this case, it's possible to resume target in the background, and interact
5384 with GDB while the target is running. "show target-async" displays the
5385 current state of asynchronous execution of the target.
5387 set target-wide-charset
5388 show target-wide-charset
5389 The target-wide-charset is the name of the character set that GDB
5390 uses when printing characters whose type is wchar_t.
5392 set tcp auto-retry (on|off)
5394 set tcp connect-timeout
5395 show tcp connect-timeout
5396 These commands allow GDB to retry failed TCP connections to a remote stub
5397 with a specified timeout period; this is useful if the stub is launched
5398 in parallel with GDB but may not be ready to accept connections immediately.
5400 set libthread-db-search-path
5401 show libthread-db-search-path
5402 Control list of directories which GDB will search for appropriate
5405 set schedule-multiple (on|off)
5406 show schedule-multiple
5407 Allow GDB to resume all threads of all processes or only threads of
5408 the current process.
5412 Use more aggressive caching for accesses to the stack. This improves
5413 performance of remote debugging (particularly backtraces) without
5414 affecting correctness.
5416 set interactive-mode (on|off|auto)
5417 show interactive-mode
5418 Control whether GDB runs in interactive mode (on) or not (off).
5419 When in interactive mode, GDB waits for the user to answer all
5420 queries. Otherwise, GDB does not wait and assumes the default
5421 answer. When set to auto (the default), GDB determines which
5422 mode to use based on the stdin settings.
5427 For program forks, this is replaced by the new more generic `info
5428 inferiors' command. To list checkpoints, you can still use the
5429 `info checkpoints' command, which was an alias for the `info forks'
5433 Replaced by the new `inferior' command. To switch between
5434 checkpoints, you can still use the `restart' command, which was an
5435 alias for the `fork' command.
5438 This is removed, since some targets don't have a notion of
5439 processes. To switch between processes, you can still use the
5440 `inferior' command using GDB's own inferior number.
5443 For program forks, this is replaced by the new more generic `kill
5444 inferior' command. To delete a checkpoint, you can still use the
5445 `delete checkpoint' command, which was an alias for the `delete
5449 For program forks, this is replaced by the new more generic `detach
5450 inferior' command. To detach a checkpoint, you can still use the
5451 `detach checkpoint' command, which was an alias for the `detach
5454 * New native configurations
5456 x86/x86_64 Darwin i[34567]86-*-darwin*
5458 x86_64 MinGW x86_64-*-mingw*
5462 Lattice Mico32 lm32-*
5463 x86 DICOS i[34567]86-*-dicos*
5464 x86_64 DICOS x86_64-*-dicos*
5467 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5468 (mingw32ce) debugging.
5474 These commands were actually not implemented on any target.
5476 *** Changes in GDB 6.8
5478 * New native configurations
5480 NetBSD/hppa hppa*-*netbsd*
5481 Xtensa GNU/Linux xtensa*-*-linux*
5485 NetBSD/hppa hppa*-*-netbsd*
5486 Xtensa GNU/Linux xtensa*-*-linux*
5488 * Change in command line behavior -- corefiles vs. process ids.
5490 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5491 attaching to process NUMBER fails, GDB no longer attempts to open a
5492 core file named NUMBER. Attaching to a program using the -c option
5493 is no longer supported. Instead, use the '-p' or '--pid' options.
5495 * GDB can now be built as a native debugger for debugging Windows x86
5496 (mingw32) Portable Executable (PE) programs.
5498 * Pending breakpoints no longer change their number when their address
5501 * GDB now supports breakpoints with multiple locations,
5502 including breakpoints on C++ constructors, inside C++ templates,
5503 and in inlined functions.
5505 * GDB's ability to debug optimized code has been improved. GDB more
5506 accurately identifies function bodies and lexical blocks that occupy
5507 more than one contiguous range of addresses.
5509 * Target descriptions can now describe registers for PowerPC.
5511 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5512 registers on PowerPC targets.
5514 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5515 targets even when the libthread_db library is not available.
5517 * The GDB remote stub, gdbserver, now supports the new file transfer
5518 commands (remote put, remote get, and remote delete).
5520 * The GDB remote stub, gdbserver, now supports run and attach in
5521 extended-remote mode.
5523 * hppa*64*-*-hpux11* target broken
5524 The debugger is unable to start a program and fails with the following
5525 error: "Error trying to get information about dynamic linker".
5526 The gdb-6.7 release is also affected.
5528 * GDB now supports the --enable-targets= configure option to allow
5529 building a single GDB executable that supports multiple remote
5530 target architectures.
5532 * GDB now supports debugging C and C++ programs which use the
5533 Decimal Floating Point extension. In addition, the PowerPC target
5534 now has a set of pseudo-registers to inspect decimal float values
5535 stored in two consecutive float registers.
5537 * The -break-insert MI command can optionally create pending
5540 * Improved support for debugging Ada
5541 Many improvements to the Ada language support have been made. These
5543 - Better support for Ada2005 interface types
5544 - Improved handling of arrays and slices in general
5545 - Better support for Taft-amendment types
5546 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5548 - Improved command completion in Ada
5551 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5556 set print frame-arguments (all|scalars|none)
5557 show print frame-arguments
5558 The value of this variable can be changed to control which argument
5559 values should be printed by the debugger when displaying a frame.
5564 Transfer files to and from a remote target, and delete remote files.
5571 Transfer files to and from a remote target, and delete remote files.
5573 * New remote packets
5580 Open, close, read, write, and delete files on the remote system.
5583 Attach to an existing process on the remote system, in extended-remote
5587 Run a new process on the remote system, in extended-remote mode.
5589 *** Changes in GDB 6.7
5591 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5592 bfd, libiberty and opcodes, as revealed by static analysis donated by
5593 Coverity, Inc. (http://scan.coverity.com).
5595 * When looking up multiply-defined global symbols, GDB will now prefer the
5596 symbol definition in the current shared library if it was built using the
5597 -Bsymbolic linker option.
5599 * When the Text User Interface (TUI) is not configured, GDB will now
5600 recognize the -tui command-line option and print a message that the TUI
5603 * The GDB remote stub, gdbserver, now has lower overhead for high
5604 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5606 * GDB for MIPS targets now autodetects whether a remote target provides
5607 32-bit or 64-bit register values.
5609 * Support for C++ member pointers has been improved.
5611 * GDB now understands XML target descriptions, which specify the
5612 target's overall architecture. GDB can read a description from
5613 a local file or over the remote serial protocol.
5615 * Vectors of single-byte data use a new integer type which is not
5616 automatically displayed as character or string data.
5618 * The /s format now works with the print command. It displays
5619 arrays of single-byte integers and pointers to single-byte integers
5622 * Target descriptions can now describe target-specific registers,
5623 for architectures which have implemented the support (currently
5624 only ARM, M68K, and MIPS).
5626 * GDB and the GDB remote stub, gdbserver, now support the XScale
5629 * The GDB remote stub, gdbserver, has been updated to support
5630 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5631 has been rewritten to use the standard GDB remote protocol.
5633 * GDB can now step into C++ functions which are called through thunks.
5635 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5637 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5638 layout. It also supports a TextSeg= and DataSeg= response when only
5639 segment base addresses (rather than offsets) are available.
5641 * The /i format now outputs any trailing branch delay slot instructions
5642 immediately following the last instruction within the count specified.
5644 * The GDB remote protocol "T" stop reply packet now supports a
5645 "library" response. Combined with the new "qXfer:libraries:read"
5646 packet, this response allows GDB to debug shared libraries on targets
5647 where the operating system manages the list of loaded libraries (e.g.
5648 Windows and SymbianOS).
5650 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5651 (DLLs) on Windows and Windows CE targets.
5653 * GDB now supports a faster verification that a .debug file matches its binary
5654 according to its build-id signature, if the signature is present.
5660 Enable or disable hardware flow control (RTS/CTS) on the serial port
5661 when debugging using remote targets.
5663 set mem inaccessible-by-default
5664 show mem inaccessible-by-default
5665 If the target supplies a memory map, for instance via the remote
5666 protocol's "qXfer:memory-map:read" packet, setting this variable
5667 prevents GDB from accessing memory outside the memory map. This
5668 is useful for targets with memory mapped registers or which react
5669 badly to accesses of unmapped address space.
5671 set breakpoint auto-hw
5672 show breakpoint auto-hw
5673 If the target supplies a memory map, for instance via the remote
5674 protocol's "qXfer:memory-map:read" packet, setting this variable
5675 lets GDB use hardware breakpoints automatically for memory regions
5676 where it can not use software breakpoints. This covers both the
5677 "break" command and internal breakpoints used for other commands
5678 including "next" and "finish".
5681 catch exception unhandled
5682 Stop the program execution when Ada exceptions are raised.
5685 Stop the program execution when an Ada assertion failed.
5689 Set an alternate system root for target files. This is a more
5690 general version of "set solib-absolute-prefix", which is now
5691 an alias to "set sysroot".
5694 Provide extended SPU facility status information. This set of
5695 commands is available only when debugging the Cell/B.E. SPU
5698 * New native configurations
5700 OpenBSD/sh sh*-*openbsd*
5703 unset tdesc filename
5705 Use the specified local file as an XML target description, and do
5706 not query the target for its built-in description.
5710 OpenBSD/sh sh*-*-openbsd*
5711 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5712 Toshiba Media Processor mep-elf
5714 * New remote packets
5717 Ignore the specified signals; pass them directly to the debugged program
5718 without stopping other threads or reporting them to GDB.
5720 qXfer:features:read:
5721 Read an XML target description from the target, which describes its
5726 Read or write contents of an spufs file on the target system. These
5727 packets are available only on the Cell/B.E. SPU architecture.
5729 qXfer:libraries:read:
5730 Report the loaded shared libraries. Combined with new "T" packet
5731 response, this packet allows GDB to debug shared libraries on
5732 targets where the operating system manages the list of loaded
5733 libraries (e.g. Windows and SymbianOS).
5737 Support for these obsolete configurations has been removed.
5745 i[34567]86-*-lynxos*
5746 i[34567]86-*-netware*
5747 i[34567]86-*-sco3.2v5*
5748 i[34567]86-*-sco3.2v4*
5750 i[34567]86-*-sysv4.2*
5753 i[34567]86-*-unixware2*
5754 i[34567]86-*-unixware*
5763 * Other removed features
5770 Various m68k-only ROM monitors.
5777 Various Renesas ROM monitors and debugging interfaces for SH and
5782 Support for a Macraigor serial interface to on-chip debugging.
5783 GDB does not directly support the newer parallel or USB
5788 A debug information format. The predecessor to DWARF 2 and
5789 DWARF 3, which are still supported.
5791 Support for the HP aCC compiler on HP-UX/PA-RISC
5793 SOM-encapsulated symbolic debugging information, automatic
5794 invocation of pxdb, and the aCC custom C++ ABI. This does not
5795 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5796 with aCC can still be debugged on an assembly level.
5798 MIPS ".pdr" sections
5800 A MIPS-specific format used to describe stack frame layout
5801 in debugging information.
5805 GDB could work with an older version of Guile to debug
5806 the interpreter and Scheme programs running in it.
5808 set mips stack-arg-size
5809 set mips saved-gpreg-size
5811 Use "set mips abi" to control parameter passing for MIPS.
5813 *** Changes in GDB 6.6
5818 Cell Broadband Engine SPU spu-elf
5820 * GDB can now be configured as a cross-debugger targeting native Windows
5821 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5822 running on a Windows system over TCP/IP to debug Windows programs.
5824 * The GDB remote stub, gdbserver, has been updated to support Windows and
5825 Cygwin debugging. Both single-threaded and multi-threaded programs are
5828 * The "set trust-readonly-sections" command works again. This command was
5829 broken in GDB 6.3, 6.4, and 6.5.
5831 * The "load" command now supports writing to flash memory, if the remote
5832 stub provides the required support.
5834 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5835 longer requires symbolic debug information (e.g. DWARF-2).
5840 unset substitute-path
5841 show substitute-path
5842 Manage a list of substitution rules that GDB uses to rewrite the name
5843 of the directories where the sources are located. This can be useful
5844 for instance when the sources were moved to a different location
5845 between compilation and debugging.
5849 Print each CLI command as it is executed. Each command is prefixed with
5850 a number of `+' symbols representing the nesting depth.
5851 The source command now has a `-v' option to enable the same feature.
5855 The ARM Demon monitor support (RDP protocol, "target rdp").
5857 Kernel Object Display, an embedded debugging feature which only worked with
5858 an obsolete version of Cisco IOS.
5860 The 'set download-write-size' and 'show download-write-size' commands.
5862 * New remote packets
5865 Tell a stub about GDB client features, and request remote target features.
5866 The first feature implemented is PacketSize, which allows the target to
5867 specify the size of packets it can handle - to minimize the number of
5868 packets required and improve performance when connected to a remote
5872 Fetch an OS auxilliary vector from the remote stub. This packet is a
5873 more efficient replacement for qPart:auxv:read.
5875 qXfer:memory-map:read:
5876 Fetch a memory map from the remote stub, including information about
5877 RAM, ROM, and flash memory devices.
5882 Erase and program a flash memory device.
5884 * Removed remote packets
5887 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5888 used it, and only gdbserver implemented it.
5890 *** Changes in GDB 6.5
5894 Renesas M32C/M16C m32c-elf
5896 Morpho Technologies ms1 ms1-elf
5900 init-if-undefined Initialize a convenience variable, but
5901 only if it doesn't already have a value.
5903 The following commands are presently only implemented for native GNU/Linux:
5905 checkpoint Save a snapshot of the program state.
5907 restart <n> Return the program state to a
5908 previously saved state.
5910 info checkpoints List currently saved checkpoints.
5912 delete-checkpoint <n> Delete a previously saved checkpoint.
5914 set|show detach-on-fork Tell gdb whether to detach from a newly
5915 forked process, or to keep debugging it.
5917 info forks List forks of the user program that
5918 are available to be debugged.
5920 fork <n> Switch to debugging one of several
5921 forks of the user program that are
5922 available to be debugged.
5924 delete-fork <n> Delete a fork from the list of forks
5925 that are available to be debugged (and
5926 kill the forked process).
5928 detach-fork <n> Delete a fork from the list of forks
5929 that are available to be debugged (and
5930 allow the process to continue).
5934 Morpho Technologies ms2 ms1-elf
5936 * Improved Windows host support
5938 GDB now builds as a cross debugger hosted on i686-mingw32, including
5939 native console support, and remote communications using either
5940 network sockets or serial ports.
5942 * Improved Modula-2 language support
5944 GDB can now print most types in the Modula-2 syntax. This includes:
5945 basic types, set types, record types, enumerated types, range types,
5946 pointer types and ARRAY types. Procedure var parameters are correctly
5947 printed and hexadecimal addresses and character constants are also
5948 written in the Modula-2 syntax. Best results can be obtained by using
5949 GNU Modula-2 together with the -gdwarf-2 command line option.
5953 The ARM rdi-share module.
5955 The Netware NLM debug server.
5957 *** Changes in GDB 6.4
5959 * New native configurations
5961 OpenBSD/arm arm*-*-openbsd*
5962 OpenBSD/mips64 mips64-*-openbsd*
5966 Morpho Technologies ms1 ms1-elf
5968 * New command line options
5970 --batch-silent As for --batch, but totally silent.
5971 --return-child-result The debugger will exist with the same value
5972 the child (debugged) program exited with.
5973 --eval-command COMMAND, -ex COMMAND
5974 Execute a single GDB CLI command. This may be
5975 specified multiple times and in conjunction
5976 with the --command (-x) option.
5978 * Deprecated commands removed
5980 The following commands, that were deprecated in 2000, have been
5984 set|show arm disassembly-flavor set|show arm disassembler
5985 othernames set arm disassembler
5986 set|show remotedebug set|show debug remote
5987 set|show archdebug set|show debug arch
5988 set|show eventdebug set|show debug event
5991 * New BSD user-level threads support
5993 It is now possible to debug programs using the user-level threads
5994 library on OpenBSD and FreeBSD. Currently supported (target)
5997 FreeBSD/amd64 x86_64-*-freebsd*
5998 FreeBSD/i386 i386-*-freebsd*
5999 OpenBSD/i386 i386-*-openbsd*
6001 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6002 are not yet supported.
6004 * New support for Matsushita MN10300 w/sim added
6005 (Work in progress). mn10300-elf.
6007 * REMOVED configurations and files
6009 VxWorks and the XDR protocol *-*-vxworks
6010 Motorola MCORE mcore-*-*
6011 National Semiconductor NS32000 ns32k-*-*
6013 * New "set print array-indexes" command
6015 After turning this setting "on", GDB prints the index of each element
6016 when displaying arrays. The default is "off" to preserve the previous
6019 * VAX floating point support
6021 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6023 * User-defined command support
6025 In addition to using $arg0..$arg9 for argument passing, it is now possible
6026 to use $argc to determine now many arguments have been passed. See the
6027 section on user-defined commands in the user manual for more information.
6029 *** Changes in GDB 6.3:
6031 * New command line option
6033 GDB now accepts -l followed by a number to set the timeout for remote
6036 * GDB works with GCC -feliminate-dwarf2-dups
6038 GDB now supports a more compact representation of DWARF-2 debug
6039 information using DW_FORM_ref_addr references. These are produced
6040 by GCC with the option -feliminate-dwarf2-dups and also by some
6041 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6042 to use -feliminate-dwarf2-dups.
6044 * Internationalization
6046 When supported by the host system, GDB will be built with
6047 internationalization (libintl). The task of marking up the sources is
6048 continued, we're looking forward to our first translation.
6052 Initial support for debugging programs compiled with the GNAT
6053 implementation of the Ada programming language has been integrated
6054 into GDB. In this release, support is limited to expression evaluation.
6056 * New native configurations
6058 GNU/Linux/m32r m32r-*-linux-gnu
6062 GDB's remote protocol now includes support for the 'p' packet. This
6063 packet is used to fetch individual registers from a remote inferior.
6065 * END-OF-LIFE registers[] compatibility module
6067 GDB's internal register infrastructure has been completely rewritten.
6068 The new infrastructure making possible the implementation of key new
6069 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6072 GDB 6.3 will be the last release to include the registers[]
6073 compatibility module that allowed out-of-date configurations to
6074 continue to work. This change directly impacts the following
6084 powerpc bdm protocol
6086 Unless there is activity to revive these configurations, they will be
6087 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6089 * OBSOLETE configurations and files
6091 Configurations that have been declared obsolete in this release have
6092 been commented out. Unless there is activity to revive these
6093 configurations, the next release of GDB will have their sources
6094 permanently REMOVED.
6103 *** Changes in GDB 6.2.1:
6105 * MIPS `break main; run' gave an heuristic-fence-post warning
6107 When attempting to run even a simple program, a warning about
6108 heuristic-fence-post being hit would be reported. This problem has
6111 * MIPS IRIX 'long double' crashed GDB
6113 When examining a long double variable, GDB would get a segmentation
6114 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6115 IRIX long double values).
6119 A bug in the VAX stack code was causing problems with the "next"
6120 command. This problem has been fixed.
6122 *** Changes in GDB 6.2:
6124 * Fix for ``many threads''
6126 On GNU/Linux systems that use the NPTL threads library, a program
6127 rapidly creating and deleting threads would confuse GDB leading to the
6130 ptrace: No such process.
6131 thread_db_get_info: cannot get thread info: generic error
6133 This problem has been fixed.
6135 * "-async" and "-noasync" options removed.
6137 Support for the broken "-noasync" option has been removed (it caused
6140 * New ``start'' command.
6142 This command runs the program until the beginning of the main procedure.
6144 * New BSD Kernel Data Access Library (libkvm) interface
6146 Using ``target kvm'' it is now possible to debug kernel core dumps and
6147 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6148 platforms. Currently supported (native-only) configurations are:
6150 FreeBSD/amd64 x86_64-*-freebsd*
6151 FreeBSD/i386 i?86-*-freebsd*
6152 NetBSD/i386 i?86-*-netbsd*
6153 NetBSD/m68k m68*-*-netbsd*
6154 NetBSD/sparc sparc-*-netbsd*
6155 OpenBSD/amd64 x86_64-*-openbsd*
6156 OpenBSD/i386 i?86-*-openbsd*
6157 OpenBSD/m68k m68*-openbsd*
6158 OpenBSD/sparc sparc-*-openbsd*
6160 * Signal trampoline code overhauled
6162 Many generic problems with GDB's signal handling code have been fixed.
6163 These include: backtraces through non-contiguous stacks; recognition
6164 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6165 call; backtrace through a signal trampoline; step into and out of
6166 signal handlers; and single-stepping in the signal trampoline.
6168 Please note that kernel bugs are a limiting factor here. These
6169 features have been shown to work on an s390 GNU/Linux system that
6170 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6172 * Cygwin support for DWARF 2 added.
6174 * New native configurations
6176 GNU/Linux/hppa hppa*-*-linux*
6177 OpenBSD/hppa hppa*-*-openbsd*
6178 OpenBSD/m68k m68*-*-openbsd*
6179 OpenBSD/m88k m88*-*-openbsd*
6180 OpenBSD/powerpc powerpc-*-openbsd*
6181 NetBSD/vax vax-*-netbsd*
6182 OpenBSD/vax vax-*-openbsd*
6184 * END-OF-LIFE frame compatibility module
6186 GDB's internal frame infrastructure has been completely rewritten.
6187 The new infrastructure making it possible to support key new features
6188 including DWARF 2 Call Frame Information. To aid in the task of
6189 migrating old configurations to this new infrastructure, a
6190 compatibility module, that allowed old configurations to continue to
6191 work, was also included.
6193 GDB 6.2 will be the last release to include this frame compatibility
6194 module. This change directly impacts the following configurations:
6204 Unless there is activity to revive these configurations, they will be
6205 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6207 * REMOVED configurations and files
6209 Sun 3, running SunOS 3 m68*-*-sunos3*
6210 Sun 3, running SunOS 4 m68*-*-sunos4*
6211 Sun 2, running SunOS 3 m68000-*-sunos3*
6212 Sun 2, running SunOS 4 m68000-*-sunos4*
6213 Motorola 680x0 running LynxOS m68*-*-lynxos*
6214 AT&T 3b1/Unix pc m68*-att-*
6215 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6216 decstation mips-dec-* mips-little-*
6217 riscos mips-*-riscos* mips-*-sysv*
6218 sonymips mips-sony-*
6219 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6221 *** Changes in GDB 6.1.1:
6223 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6225 The TUI (Text-mode User Interface) is now built as part of a default
6226 GDB configuration. It is enabled by either selecting the TUI with the
6227 command line option "-i=tui" or by running the separate "gdbtui"
6228 program. For more information on the TUI, see the manual "Debugging
6231 * Pending breakpoint support (also included in GDB 6.1)
6233 Support has been added to allow you to specify breakpoints in shared
6234 libraries that have not yet been loaded. If a breakpoint location
6235 cannot be found, and the "breakpoint pending" option is set to auto,
6236 GDB queries you if you wish to make the breakpoint pending on a future
6237 shared-library load. If and when GDB resolves the breakpoint symbol,
6238 the pending breakpoint is removed as one or more regular breakpoints
6241 Pending breakpoints are very useful for GCJ Java debugging.
6243 * Fixed ISO-C build problems
6245 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6246 non ISO-C code that stopped them being built using a more strict ISO-C
6247 compiler (e.g., IBM's C compiler).
6249 * Fixed build problem on IRIX 5
6251 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6252 wasn't able to compile compile on an IRIX 5 system.
6254 * Added execute permission to gdb/gdbserver/configure
6256 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6257 permission. This bug would cause configure to fail on a number of
6258 systems (Solaris, IRIX). Ref: server/519.
6260 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6262 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6263 has been updated to use constant array sizes.
6265 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6267 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6268 its generated DWARF Call Frame Info. This encoding was causing GDB to
6269 panic, that panic has been fixed. Ref: gdb/1628.
6271 * Fixed a problem when examining parameters in shared library code.
6273 When examining parameters in optimized shared library code generated
6274 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6275 not available''. GDB now correctly displays the variable's value.
6277 *** Changes in GDB 6.1:
6279 * Removed --with-mmalloc
6281 Support for the mmalloc memory manager has been removed, as it
6282 conflicted with the internal gdb byte cache.
6284 * Changes in AMD64 configurations
6286 The AMD64 target now includes the %cs and %ss registers. As a result
6287 the AMD64 remote protocol has changed; this affects the floating-point
6288 and SSE registers. If you rely on those registers for your debugging,
6289 you should upgrade gdbserver on the remote side.
6291 * Revised SPARC target
6293 The SPARC target has been completely revised, incorporating the
6294 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6295 support for LynxOS and SunOS 4 has been dropped. Calling functions
6296 from within GDB on operating systems with a non-executable stack
6297 (Solaris, OpenBSD) now works.
6301 GDB has a new C++ demangler which does a better job on the mangled
6302 names generated by current versions of g++. It also runs faster, so
6303 with this and other changes gdb should now start faster on large C++
6306 * DWARF 2 Location Expressions
6308 GDB support for location expressions has been extended to support function
6309 arguments and frame bases. Older versions of GDB could crash when they
6312 * C++ nested types and namespaces
6314 GDB's support for nested types and namespaces in C++ has been
6315 improved, especially if you use the DWARF 2 debugging format. (This
6316 is the default for recent versions of GCC on most platforms.)
6317 Specifically, if you have a class "Inner" defined within a class or
6318 namespace "Outer", then GDB realizes that the class's name is
6319 "Outer::Inner", not simply "Inner". This should greatly reduce the
6320 frequency of complaints about not finding RTTI symbols. In addition,
6321 if you are stopped at inside of a function defined within a namespace,
6322 GDB modifies its name lookup accordingly.
6324 * New native configurations
6326 NetBSD/amd64 x86_64-*-netbsd*
6327 OpenBSD/amd64 x86_64-*-openbsd*
6328 OpenBSD/alpha alpha*-*-openbsd*
6329 OpenBSD/sparc sparc-*-openbsd*
6330 OpenBSD/sparc64 sparc64-*-openbsd*
6332 * New debugging protocols
6334 M32R with SDI protocol m32r-*-elf*
6336 * "set prompt-escape-char" command deleted.
6338 The command "set prompt-escape-char" has been deleted. This command,
6339 and its very obscure effect on GDB's prompt, was never documented,
6340 tested, nor mentioned in the NEWS file.
6342 * OBSOLETE configurations and files
6344 Configurations that have been declared obsolete in this release have
6345 been commented out. Unless there is activity to revive these
6346 configurations, the next release of GDB will have their sources
6347 permanently REMOVED.
6349 Sun 3, running SunOS 3 m68*-*-sunos3*
6350 Sun 3, running SunOS 4 m68*-*-sunos4*
6351 Sun 2, running SunOS 3 m68000-*-sunos3*
6352 Sun 2, running SunOS 4 m68000-*-sunos4*
6353 Motorola 680x0 running LynxOS m68*-*-lynxos*
6354 AT&T 3b1/Unix pc m68*-att-*
6355 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6356 decstation mips-dec-* mips-little-*
6357 riscos mips-*-riscos* mips-*-sysv*
6358 sonymips mips-sony-*
6359 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6361 * REMOVED configurations and files
6363 SGI Irix-4.x mips-sgi-irix4 or iris4
6364 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6365 Z8000 simulator z8k-zilog-none or z8ksim
6366 Matsushita MN10200 w/simulator mn10200-*-*
6367 H8/500 simulator h8500-hitachi-hms or h8500hms
6368 HP/PA running BSD hppa*-*-bsd*
6369 HP/PA running OSF/1 hppa*-*-osf*
6370 HP/PA Pro target hppa*-*-pro*
6371 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6372 386BSD i[3456]86-*-bsd*
6373 Sequent family i[3456]86-sequent-sysv4*
6374 i[3456]86-sequent-sysv*
6375 i[3456]86-sequent-bsd*
6376 SPARC running LynxOS sparc-*-lynxos*
6377 SPARC running SunOS 4 sparc-*-sunos4*
6378 Tsqware Sparclet sparclet-*-*
6379 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6381 *** Changes in GDB 6.0:
6385 Support for debugging the Objective-C programming language has been
6386 integrated into GDB.
6388 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6390 DWARF 2's Call Frame Information makes available compiler generated
6391 information that more exactly describes the program's run-time stack.
6392 By using this information, GDB is able to provide more robust stack
6395 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6396 have been updated to use a new backtrace mechanism which includes
6397 DWARF 2 CFI support.
6401 GDB's remote protocol has been extended to include support for hosted
6402 file I/O (where the remote target uses GDB's file system). See GDB's
6403 remote protocol documentation for details.
6405 * All targets using the new architecture framework.
6407 All of GDB's targets have been updated to use the new internal
6408 architecture framework. The way is now open for future GDB releases
6409 to include cross-architecture native debugging support (i386 on amd64,
6412 * GNU/Linux's Thread Local Storage (TLS)
6414 GDB now includes support for for the GNU/Linux implementation of
6415 per-thread variables.
6417 * GNU/Linux's Native POSIX Thread Library (NPTL)
6419 GDB's thread code has been updated to work with either the new
6420 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6422 * Separate debug info.
6424 GDB, in conjunction with BINUTILS, now supports a mechanism for
6425 automatically loading debug information from a separate file. Instead
6426 of shipping full debug and non-debug versions of system libraries,
6427 system integrators can now instead ship just the stripped libraries
6428 and optional debug files.
6430 * DWARF 2 Location Expressions
6432 DWARF 2 Location Expressions allow the compiler to more completely
6433 describe the location of variables (even in optimized code) to the
6436 GDB now includes preliminary support for location expressions (support
6437 for DW_OP_piece is still missing).
6441 A number of long standing bugs that caused GDB to die while starting a
6442 Java application have been fixed. GDB's Java support is now
6443 considered "useable".
6445 * GNU/Linux support for fork, vfork, and exec.
6447 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6448 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6451 * GDB supports logging output to a file
6453 There are two new commands, "set logging" and "show logging", which can be
6454 used to capture GDB's output to a file.
6456 * The meaning of "detach" has changed for gdbserver
6458 The "detach" command will now resume the application, as documented. To
6459 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6462 * d10v, m68hc11 `regs' command deprecated
6464 The `info registers' command has been updated so that it displays the
6465 registers using a format identical to the old `regs' command.
6469 A new command, "maint set profile on/off", has been added. This command can
6470 be used to enable or disable profiling while running GDB, to profile a
6471 session or a set of commands. In addition there is a new configure switch,
6472 "--enable-profiling", which will cause GDB to be compiled with profiling
6473 data, for more informative profiling results.
6475 * Default MI syntax changed to "mi2".
6477 The default MI (machine interface) syntax, enabled by the command line
6478 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6479 "mi1", can be enabled by specifying the option "-i=mi1".
6481 Support for the original "mi0" syntax (included in GDB 5.0) has been
6484 Fix for gdb/192: removed extraneous space when displaying frame level.
6485 Fix for gdb/672: update changelist is now output in mi list format.
6486 Fix for gdb/702: a -var-assign that updates the value now shows up
6487 in a subsequent -var-update.
6489 * New native configurations.
6491 FreeBSD/amd64 x86_64-*-freebsd*
6493 * Multi-arched targets.
6495 HP/PA HPUX11 hppa*-*-hpux*
6496 Renesas M32R/D w/simulator m32r-*-elf*
6498 * OBSOLETE configurations and files
6500 Configurations that have been declared obsolete in this release have
6501 been commented out. Unless there is activity to revive these
6502 configurations, the next release of GDB will have their sources
6503 permanently REMOVED.
6505 Z8000 simulator z8k-zilog-none or z8ksim
6506 Matsushita MN10200 w/simulator mn10200-*-*
6507 H8/500 simulator h8500-hitachi-hms or h8500hms
6508 HP/PA running BSD hppa*-*-bsd*
6509 HP/PA running OSF/1 hppa*-*-osf*
6510 HP/PA Pro target hppa*-*-pro*
6511 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6512 Sequent family i[3456]86-sequent-sysv4*
6513 i[3456]86-sequent-sysv*
6514 i[3456]86-sequent-bsd*
6515 Tsqware Sparclet sparclet-*-*
6516 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6518 * REMOVED configurations and files
6521 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6522 IBM AIX PS/2 i[3456]86-*-aix
6523 i386 running Mach 3.0 i[3456]86-*-mach3*
6524 i386 running Mach i[3456]86-*-mach*
6525 i386 running OSF/1 i[3456]86-*osf1mk*
6526 HP/Apollo 68k Family m68*-apollo*-sysv*,
6528 m68*-hp-bsd*, m68*-hp-hpux*
6529 Argonaut Risc Chip (ARC) arc-*-*
6530 Mitsubishi D30V d30v-*-*
6531 Fujitsu FR30 fr30-*-elf*
6532 OS/9000 i[34]86-*-os9k
6533 I960 with MON960 i960-*-coff
6535 * MIPS $fp behavior changed
6537 The convenience variable $fp, for the MIPS, now consistently returns
6538 the address of the current frame's base. Previously, depending on the
6539 context, $fp could refer to either $sp or the current frame's base
6540 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6541 The GNU Source-Level Debugger''.
6543 *** Changes in GDB 5.3:
6545 * GNU/Linux shared library multi-threaded performance improved.
6547 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6548 `/proc', in preference to `ptrace' for memory reads. This may result
6549 in an improvement in the start-up time of multi-threaded, shared
6550 library applications when run under GDB. One GDB user writes: ``loads
6551 shared libs like mad''.
6553 * ``gdbserver'' now supports multi-threaded applications on some targets
6555 Support for debugging multi-threaded applications which use
6556 the GNU/Linux LinuxThreads package has been added for
6557 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6558 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6560 * GDB now supports C/C++ preprocessor macros.
6562 GDB now expands preprocessor macro invocations in C/C++ expressions,
6563 and provides various commands for showing macro definitions and how
6566 The new command `macro expand EXPRESSION' expands any macro
6567 invocations in expression, and shows the result.
6569 The new command `show macro MACRO-NAME' shows the definition of the
6570 macro named MACRO-NAME, and where it was defined.
6572 Most compilers don't include information about macros in the debugging
6573 information by default. In GCC 3.1, for example, you need to compile
6574 your program with the options `-gdwarf-2 -g3'. If the macro
6575 information is present in the executable, GDB will read it.
6577 * Multi-arched targets.
6579 DEC Alpha (partial) alpha*-*-*
6580 DEC VAX (partial) vax-*-*
6582 National Semiconductor NS32000 (partial) ns32k-*-*
6583 Motorola 68000 (partial) m68k-*-*
6584 Motorola MCORE mcore-*-*
6588 Fujitsu FRV architecture added by Red Hat frv*-*-*
6591 * New native configurations
6593 Alpha NetBSD alpha*-*-netbsd*
6594 SH NetBSD sh*-*-netbsdelf*
6595 MIPS NetBSD mips*-*-netbsd*
6596 UltraSPARC NetBSD sparc64-*-netbsd*
6598 * OBSOLETE configurations and files
6600 Configurations that have been declared obsolete in this release have
6601 been commented out. Unless there is activity to revive these
6602 configurations, the next release of GDB will have their sources
6603 permanently REMOVED.
6605 Mitsubishi D30V d30v-*-*
6606 OS/9000 i[34]86-*-os9k
6607 IBM AIX PS/2 i[3456]86-*-aix
6608 Fujitsu FR30 fr30-*-elf*
6609 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6610 Argonaut Risc Chip (ARC) arc-*-*
6611 i386 running Mach 3.0 i[3456]86-*-mach3*
6612 i386 running Mach i[3456]86-*-mach*
6613 i386 running OSF/1 i[3456]86-*osf1mk*
6614 HP/Apollo 68k Family m68*-apollo*-sysv*,
6616 m68*-hp-bsd*, m68*-hp-hpux*
6617 I960 with MON960 i960-*-coff
6619 * OBSOLETE languages
6621 CHILL, a Pascal like language used by telecommunications companies.
6623 * REMOVED configurations and files
6625 AMD 29k family via UDI a29k-amd-udi, udi29k
6626 A29K VxWorks a29k-*-vxworks
6627 AMD 29000 embedded, using EBMON a29k-none-none
6628 AMD 29000 embedded with COFF a29k-none-coff
6629 AMD 29000 embedded with a.out a29k-none-aout
6631 testsuite/gdb.hp/gdb.threads-hp/ directory
6633 * New command "set max-user-call-depth <nnn>"
6635 This command allows the user to limit the call depth of user-defined
6636 commands. The default is 1024.
6638 * Changes in FreeBSD/i386 native debugging.
6640 Support for the "generate-core-file" has been added.
6642 * New commands "dump", "append", and "restore".
6644 These commands allow data to be copied from target memory
6645 to a bfd-format or binary file (dump and append), and back
6646 from a file into memory (restore).
6648 * Improved "next/step" support on multi-processor Alpha Tru64.
6650 The previous single-step mechanism could cause unpredictable problems,
6651 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6652 of a software single-step mechanism prevents this.
6654 *** Changes in GDB 5.2.1:
6662 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6663 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6664 Fix, by Joel Brobecker imported from mainline.
6666 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6667 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6668 Fix, by Fred Fish, imported from mainline.
6670 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6671 Surprisingly enough, it works now.
6672 By Michal Ludvig, imported from mainline.
6674 i386 hardware watchpoint support:
6675 avoid misses on second run for some targets.
6676 By Pierre Muller, imported from mainline.
6678 *** Changes in GDB 5.2:
6680 * New command "set trust-readonly-sections on[off]".
6682 This command is a hint that tells gdb that read-only sections
6683 really are read-only (ie. that their contents will not change).
6684 In this mode, gdb will go to the object file rather than the
6685 target to read memory from read-only sections (such as ".text").
6686 This can be a significant performance improvement on some
6687 (notably embedded) targets.
6689 * New command "generate-core-file" (or "gcore").
6691 This new gdb command allows the user to drop a core file of the child
6692 process state at any time. So far it's been implemented only for
6693 GNU/Linux and Solaris, but should be relatively easily ported to other
6694 hosts. Argument is core file name (defaults to core.<pid>).
6696 * New command line option
6698 GDB now accepts --pid or -p followed by a process id.
6700 * Change in command line behavior -- corefiles vs. process ids.
6702 There is a subtle behavior in the way in which GDB handles
6703 command line arguments. The first non-flag argument is always
6704 a program to debug, but the second non-flag argument may either
6705 be a corefile or a process id. Previously, GDB would attempt to
6706 open the second argument as a corefile, and if that failed, would
6707 issue a superfluous error message and then attempt to attach it as
6708 a process. Now, if the second argument begins with a non-digit,
6709 it will be treated as a corefile. If it begins with a digit,
6710 GDB will attempt to attach it as a process, and if no such process
6711 is found, will then attempt to open it as a corefile.
6713 * Changes in ARM configurations.
6715 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6716 configuration is fully multi-arch.
6718 * New native configurations
6720 ARM NetBSD arm*-*-netbsd*
6721 x86 OpenBSD i[3456]86-*-openbsd*
6722 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6723 Sparc64 running FreeBSD sparc64-*-freebsd*
6727 Sanyo XStormy16 xstormy16-elf
6729 * OBSOLETE configurations and files
6731 Configurations that have been declared obsolete in this release have
6732 been commented out. Unless there is activity to revive these
6733 configurations, the next release of GDB will have their sources
6734 permanently REMOVED.
6736 AMD 29k family via UDI a29k-amd-udi, udi29k
6737 A29K VxWorks a29k-*-vxworks
6738 AMD 29000 embedded, using EBMON a29k-none-none
6739 AMD 29000 embedded with COFF a29k-none-coff
6740 AMD 29000 embedded with a.out a29k-none-aout
6742 testsuite/gdb.hp/gdb.threads-hp/ directory
6744 * REMOVED configurations and files
6746 TI TMS320C80 tic80-*-*
6748 PowerPC Solaris powerpcle-*-solaris*
6749 PowerPC Windows NT powerpcle-*-cygwin32
6750 PowerPC Netware powerpc-*-netware*
6751 Harris/CXUX m88k m88*-harris-cxux*
6752 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6753 ns32k-utek-sysv* ns32k-utek-*
6754 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6755 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6756 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6757 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6758 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6760 * Changes to command line processing
6762 The new `--args' feature can be used to specify command-line arguments
6763 for the inferior from gdb's command line.
6765 * Changes to key bindings
6767 There is a new `operate-and-get-next' function bound to `C-o'.
6769 *** Changes in GDB 5.1.1
6771 Fix compile problem on DJGPP.
6773 Fix a problem with floating-point registers on the i386 being
6776 Fix to stop GDB crashing on .debug_str debug info.
6778 Numerous documentation fixes.
6780 Numerous testsuite fixes.
6782 *** Changes in GDB 5.1:
6784 * New native configurations
6786 Alpha FreeBSD alpha*-*-freebsd*
6787 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6788 MIPS GNU/Linux mips*-*-linux*
6789 MIPS SGI Irix 6.x mips*-sgi-irix6*
6790 ia64 AIX ia64-*-aix*
6791 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6795 Motorola 68HC11 and 68HC12 m68hc11-elf
6797 UltraSparc running GNU/Linux sparc64-*-linux*
6799 * OBSOLETE configurations and files
6801 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6802 Harris/CXUX m88k m88*-harris-cxux*
6803 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6804 ns32k-utek-sysv* ns32k-utek-*
6805 TI TMS320C80 tic80-*-*
6807 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6808 PowerPC Solaris powerpcle-*-solaris*
6809 PowerPC Windows NT powerpcle-*-cygwin32
6810 PowerPC Netware powerpc-*-netware*
6811 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6812 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6813 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6814 Apple Macintosh (MPW) host N/A
6816 stuff.c (Program to stuff files into a specially prepared space in kdb)
6817 kdb-start.c (Main loop for the standalone kernel debugger)
6819 Configurations that have been declared obsolete in this release have
6820 been commented out. Unless there is activity to revive these
6821 configurations, the next release of GDB will have their sources
6822 permanently REMOVED.
6824 * REMOVED configurations and files
6826 Altos 3068 m68*-altos-*
6827 Convex c1-*-*, c2-*-*
6829 ARM RISCix arm-*-* (as host)
6833 * GDB has been converted to ISO C.
6835 GDB's source code has been converted to ISO C. In particular, the
6836 sources are fully protoized, and rely on standard headers being
6841 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6843 * The MI enabled by default.
6845 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6846 revised and enabled by default. Packages which use GDB as a debugging
6847 engine behind a UI or another front end are encouraged to switch to
6848 using the GDB/MI interface, instead of the old annotations interface
6849 which is now deprecated.
6851 * Support for debugging Pascal programs.
6853 GDB now includes support for debugging Pascal programs. The following
6854 main features are supported:
6856 - Pascal-specific data types such as sets;
6858 - automatic recognition of Pascal sources based on file-name
6861 - Pascal-style display of data types, variables, and functions;
6863 - a Pascal expression parser.
6865 However, some important features are not yet supported.
6867 - Pascal string operations are not supported at all;
6869 - there are some problems with boolean types;
6871 - Pascal type hexadecimal constants are not supported
6872 because they conflict with the internal variables format;
6874 - support for Pascal objects and classes is not full yet;
6876 - unlike Pascal, GDB is case-sensitive for symbol names.
6878 * Changes in completion.
6880 Commands such as `shell', `run' and `set args', which pass arguments
6881 to inferior programs, now complete on file names, similar to what
6882 users expect at the shell prompt.
6884 Commands which accept locations, such as `disassemble', `print',
6885 `breakpoint', `until', etc. now complete on filenames as well as
6886 program symbols. Thus, if you type "break foob TAB", and the source
6887 files linked into the programs include `foobar.c', that file name will
6888 be one of the candidates for completion. However, file names are not
6889 considered for completion after you typed a colon that delimits a file
6890 name from a name of a function in that file, as in "break foo.c:bar".
6892 `set demangle-style' completes on available demangling styles.
6894 * New platform-independent commands:
6896 It is now possible to define a post-hook for a command as well as a
6897 hook that runs before the command. For more details, see the
6898 documentation of `hookpost' in the GDB manual.
6900 * Changes in GNU/Linux native debugging.
6902 Support for debugging multi-threaded programs has been completely
6903 revised for all platforms except m68k and sparc. You can now debug as
6904 many threads as your system allows you to have.
6906 Attach/detach is supported for multi-threaded programs.
6908 Support for SSE registers was added for x86. This doesn't work for
6909 multi-threaded programs though.
6911 * Changes in MIPS configurations.
6913 Multi-arch support is enabled for all MIPS configurations.
6915 GDB can now be built as native debugger on SGI Irix 6.x systems for
6916 debugging n32 executables. (Debugging 64-bit executables is not yet
6919 * Unified support for hardware watchpoints in all x86 configurations.
6921 Most (if not all) native x86 configurations support hardware-assisted
6922 breakpoints and watchpoints in a unified manner. This support
6923 implements debug register sharing between watchpoints, which allows to
6924 put a virtually infinite number of watchpoints on the same address,
6925 and also supports watching regions up to 16 bytes with several debug
6928 The new maintenance command `maintenance show-debug-regs' toggles
6929 debugging print-outs in functions that insert, remove, and test
6930 watchpoints and hardware breakpoints.
6932 * Changes in the DJGPP native configuration.
6934 New command ``info dos sysinfo'' displays assorted information about
6935 the CPU, OS, memory, and DPMI server.
6937 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6938 display information about segment descriptors stored in GDT, LDT, and
6941 New commands ``info dos pde'' and ``info dos pte'' display entries
6942 from Page Directory and Page Tables (for now works with CWSDPMI only).
6943 New command ``info dos address-pte'' displays the Page Table entry for
6944 a given linear address.
6946 GDB can now pass command lines longer than 126 characters to the
6947 program being debugged (requires an update to the libdbg.a library
6948 which is part of the DJGPP development kit).
6950 DWARF2 debug info is now supported.
6952 It is now possible to `step' and `next' through calls to `longjmp'.
6954 * Changes in documentation.
6956 All GDB documentation was converted to GFDL, the GNU Free
6957 Documentation License.
6959 Tracepoints-related commands are now fully documented in the GDB
6962 TUI, the Text-mode User Interface, is now documented in the manual.
6964 Tracepoints-related commands are now fully documented in the GDB
6967 The "GDB Internals" manual now has an index. It also includes
6968 documentation of `ui_out' functions, GDB coding standards, x86
6969 hardware watchpoints, and memory region attributes.
6971 * GDB's version number moved to ``version.in''
6973 The Makefile variable VERSION has been replaced by the file
6974 ``version.in''. People creating GDB distributions should update the
6975 contents of this file.
6979 GUD support is now a standard part of the EMACS distribution.
6981 *** Changes in GDB 5.0:
6983 * Improved support for debugging FP programs on x86 targets
6985 Unified and much-improved support for debugging floating-point
6986 programs on all x86 targets. In particular, ``info float'' now
6987 displays the FP registers in the same format on all x86 targets, with
6988 greater level of detail.
6990 * Improvements and bugfixes in hardware-assisted watchpoints
6992 It is now possible to watch array elements, struct members, and
6993 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6994 on x86 targets no longer erroneously trigger when the address is
6997 * Improvements in the native DJGPP version of GDB
6999 The distribution now includes all the scripts and auxiliary files
7000 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7001 machines ``out of the box''.
7003 The DJGPP version can now debug programs that use signals. It is
7004 possible to catch signals that happened in the debuggee, deliver
7005 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7006 would kill the program being debugged.) Programs that hook hardware
7007 interrupts (keyboard, timer, etc.) can also be debugged.
7009 It is now possible to debug DJGPP programs that redirect their
7010 standard handles or switch them to raw (as opposed to cooked) mode, or
7011 even close them. The command ``run < foo > bar'' works as expected,
7012 and ``info terminal'' reports useful information about the debuggee's
7013 terminal, including raw/cooked mode, redirection, etc.
7015 The DJGPP version now uses termios functions for console I/O, which
7016 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7019 DOS-style file names with drive letters are now fully supported by
7022 It is now possible to debug DJGPP programs that switch their working
7023 directory. It is also possible to rerun the debuggee any number of
7024 times without restarting GDB; thus, you can use the same setup,
7025 breakpoints, etc. for many debugging sessions.
7027 * New native configurations
7029 ARM GNU/Linux arm*-*-linux*
7030 PowerPC GNU/Linux powerpc-*-linux*
7034 Motorola MCore mcore-*-*
7035 x86 VxWorks i[3456]86-*-vxworks*
7036 PowerPC VxWorks powerpc-*-vxworks*
7037 TI TMS320C80 tic80-*-*
7039 * OBSOLETE configurations
7041 Altos 3068 m68*-altos-*
7042 Convex c1-*-*, c2-*-*
7044 ARM RISCix arm-*-* (as host)
7047 Configurations that have been declared obsolete will be commented out,
7048 but the code will be left in place. If there is no activity to revive
7049 these configurations before the next release of GDB, the sources will
7050 be permanently REMOVED.
7052 * Gould support removed
7054 Support for the Gould PowerNode and NP1 has been removed.
7056 * New features for SVR4
7058 On SVR4 native platforms (such as Solaris), if you attach to a process
7059 without first loading a symbol file, GDB will now attempt to locate and
7060 load symbols from the running process's executable file.
7062 * Many C++ enhancements
7064 C++ support has been greatly improved. Overload resolution now works properly
7065 in almost all cases. RTTI support is on the way.
7067 * Remote targets can connect to a sub-program
7069 A popen(3) style serial-device has been added. This device starts a
7070 sub-process (such as a stand-alone simulator) and then communicates
7071 with that. The sub-program to run is specified using the syntax
7072 ``|<program> <args>'' vis:
7074 (gdb) set remotedebug 1
7075 (gdb) target extended-remote |mn10300-elf-sim program-args
7077 * MIPS 64 remote protocol
7079 A long standing bug in the mips64 remote protocol where by GDB
7080 expected certain 32 bit registers (ex SR) to be transfered as 32
7081 instead of 64 bits has been fixed.
7083 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7084 added to provide backward compatibility with older versions of GDB.
7086 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7088 The command ``set remotebinarydownload'' command has been replaced by
7089 ``set remote X-packet''. Other commands in ``set remote'' family
7090 include ``set remote P-packet''.
7092 * Breakpoint commands accept ranges.
7094 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7095 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7096 ``tracepoint passcount'' also accepts a range of tracepoints.
7098 * ``apropos'' command added.
7100 The ``apropos'' command searches through command names and
7101 documentation strings, printing out matches, making it much easier to
7102 try to find a command that does what you are looking for.
7106 A new machine oriented interface (MI) has been added to GDB. This
7107 interface is designed for debug environments running GDB as a separate
7108 process. This is part of the long term libGDB project. See the
7109 "GDB/MI" chapter of the GDB manual for further information. It can be
7110 enabled by configuring with:
7112 .../configure --enable-gdbmi
7114 *** Changes in GDB-4.18:
7116 * New native configurations
7118 HP-UX 10.20 hppa*-*-hpux10.20
7119 HP-UX 11.x hppa*-*-hpux11.0*
7120 M68K GNU/Linux m68*-*-linux*
7124 Fujitsu FR30 fr30-*-elf*
7125 Intel StrongARM strongarm-*-*
7126 Mitsubishi D30V d30v-*-*
7128 * OBSOLETE configurations
7130 Gould PowerNode, NP1 np1-*-*, pn-*-*
7132 Configurations that have been declared obsolete will be commented out,
7133 but the code will be left in place. If there is no activity to revive
7134 these configurations before the next release of GDB, the sources will
7135 be permanently REMOVED.
7139 As a compatibility experiment, GDB's source files buildsym.h and
7140 buildsym.c have been converted to pure standard C, no longer
7141 containing any K&R compatibility code. We believe that all systems in
7142 use today either come with a standard C compiler, or have a GCC port
7143 available. If this is not true, please report the affected
7144 configuration to bug-gdb@gnu.org immediately. See the README file for
7145 information about getting a standard C compiler if you don't have one
7150 GDB now uses readline 2.2.
7152 * set extension-language
7154 You can now control the mapping between filename extensions and source
7155 languages by using the `set extension-language' command. For instance,
7156 you can ask GDB to treat .c files as C++ by saying
7157 set extension-language .c c++
7158 The command `info extensions' lists all of the recognized extensions
7159 and their associated languages.
7161 * Setting processor type for PowerPC and RS/6000
7163 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7164 you can use the `set processor' command to specify what variant of the
7165 PowerPC family you are debugging. The command
7169 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7170 following PowerPC and RS6000 variants:
7172 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7173 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7175 403GC IBM PowerPC 403GC
7176 505 Motorola PowerPC 505
7177 860 Motorola PowerPC 860 or 850
7178 601 Motorola PowerPC 601
7179 602 Motorola PowerPC 602
7180 603 Motorola/IBM PowerPC 603 or 603e
7181 604 Motorola PowerPC 604 or 604e
7182 750 Motorola/IBM PowerPC 750 or 750
7184 At the moment, this command just tells GDB what to name the
7185 special-purpose processor registers. Since almost all the affected
7186 registers are inaccessible to user-level programs, this command is
7187 only useful for remote debugging in its present form.
7191 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7192 more extensive support for HP-UX. Added features include shared
7193 library support, kernel threads and hardware watchpoints for 11.00,
7194 support for HP's ANSI C and C++ compilers, and a compatibility mode
7195 for xdb and dbx commands.
7199 HP's donation includes the new concept of catchpoints, which is a
7200 generalization of the old catch command. On HP-UX, it is now possible
7201 to catch exec, fork, and vfork, as well as library loading.
7203 This means that the existing catch command has changed; its first
7204 argument now specifies the type of catch to be set up. See the
7205 output of "help catch" for a list of catchpoint types.
7207 * Debugging across forks
7209 On HP-UX, you can choose which process to debug when a fork() happens
7214 HP has donated a curses-based terminal user interface (TUI). To get
7215 it, build with --enable-tui. Although this can be enabled for any
7216 configuration, at present it only works for native HP debugging.
7218 * GDB remote protocol additions
7220 A new protocol packet 'X' that writes binary data is now available.
7221 Default behavior is to try 'X', then drop back to 'M' if the stub
7222 fails to respond. The settable variable `remotebinarydownload'
7223 allows explicit control over the use of 'X'.
7225 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7226 full 64-bit address. The command
7228 set remoteaddresssize 32
7230 can be used to revert to the old behaviour. For existing remote stubs
7231 the change should not be noticed, as the additional address information
7234 In order to assist in debugging stubs, you may use the maintenance
7235 command `packet' to send any text string to the stub. For instance,
7237 maint packet heythere
7239 sends the packet "$heythere#<checksum>". Note that it is very easy to
7240 disrupt a debugging session by sending the wrong packet at the wrong
7243 The compare-sections command allows you to compare section data on the
7244 target to what is in the executable file without uploading or
7245 downloading, by comparing CRC checksums.
7247 * Tracing can collect general expressions
7249 You may now collect general expressions at tracepoints. This requires
7250 further additions to the target-side stub; see tracepoint.c and
7251 doc/agentexpr.texi for further details.
7253 * mask-address variable for Mips
7255 For Mips targets, you may control the zeroing of the upper 32 bits of
7256 a 64-bit address by entering `set mask-address on'. This is mainly
7257 of interest to users of embedded R4xxx and R5xxx processors.
7259 * Higher serial baud rates
7261 GDB's serial code now allows you to specify baud rates 57600, 115200,
7262 230400, and 460800 baud. (Note that your host system may not be able
7263 to achieve all of these rates.)
7267 The i960 configuration now includes an initial implementation of a
7268 builtin simulator, contributed by Jim Wilson.
7271 *** Changes in GDB-4.17:
7273 * New native configurations
7275 Alpha GNU/Linux alpha*-*-linux*
7276 Unixware 2.x i[3456]86-unixware2*
7277 Irix 6.x mips*-sgi-irix6*
7278 PowerPC GNU/Linux powerpc-*-linux*
7279 PowerPC Solaris powerpcle-*-solaris*
7280 Sparc GNU/Linux sparc-*-linux*
7281 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7285 Argonaut Risc Chip (ARC) arc-*-*
7286 Hitachi H8/300S h8300*-*-*
7287 Matsushita MN10200 w/simulator mn10200-*-*
7288 Matsushita MN10300 w/simulator mn10300-*-*
7289 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7290 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7291 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7292 Mitsubishi D10V w/simulator d10v-*-*
7293 Mitsubishi M32R/D w/simulator m32r-*-elf*
7294 Tsqware Sparclet sparclet-*-*
7295 NEC V850 w/simulator v850-*-*
7297 * New debugging protocols
7299 ARM with RDI protocol arm*-*-*
7300 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7301 DDB and LSI variants of PMON protocol mips*-*-*
7302 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7303 PowerPC with SDS protocol powerpc{,le}-*-eabi
7304 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7308 All configurations can now understand and use the DWARF 2 debugging
7309 format. The choice is automatic, if the symbol file contains DWARF 2
7314 GDB now includes basic Java language support. This support is
7315 only useful with Java compilers that produce native machine code.
7317 * solib-absolute-prefix and solib-search-path
7319 For SunOS and SVR4 shared libraries, you may now set the prefix for
7320 loading absolute shared library symbol files, and the search path for
7321 locating non-absolute shared library symbol files.
7323 * Live range splitting
7325 GDB can now effectively debug code for which GCC has performed live
7326 range splitting as part of its optimization. See gdb/doc/LRS for
7327 more details on the expected format of the stabs information.
7331 GDB's support for the GNU Hurd, including thread debugging, has been
7332 updated to work with current versions of the Hurd.
7336 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7337 instruction set. ARM GDB automatically detects when Thumb
7338 instructions are in use, and adjusts disassembly and backtracing
7343 GDB's MIPS target configurations now handle the MIP16 16-bit
7348 GDB now includes support for overlays; if an executable has been
7349 linked such that multiple sections are based at the same address, GDB
7350 will decide which section to use for symbolic info. You can choose to
7351 control the decision manually, using overlay commands, or implement
7352 additional target-side support and use "overlay load-target" to bring
7353 in the overlay mapping. Do "help overlay" for more detail.
7357 The command "info symbol <address>" displays information about
7358 the symbol at the specified address.
7362 The standard remote protocol now includes an extension that allows
7363 asynchronous collection and display of trace data. This requires
7364 extensive support in the target-side debugging stub. Tracing mode
7365 includes a new interaction mode in GDB and new commands: see the
7366 file tracepoint.c for more details.
7370 Configurations for embedded MIPS now include a simulator contributed
7371 by Cygnus Solutions. The simulator supports the instruction sets
7372 of most MIPS variants.
7376 Sparc configurations may now include the ERC32 simulator contributed
7377 by the European Space Agency. The simulator is not built into
7378 Sparc targets by default; configure with --enable-sim to include it.
7382 For target configurations that may include multiple variants of a
7383 basic architecture (such as MIPS and SH), you may now set the
7384 architecture explicitly. "set arch" sets, "info arch" lists
7385 the possible architectures.
7387 *** Changes in GDB-4.16:
7389 * New native configurations
7391 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7392 M68K NetBSD m68k-*-netbsd*
7393 PowerPC AIX 4.x powerpc-*-aix*
7394 PowerPC MacOS powerpc-*-macos*
7395 PowerPC Windows NT powerpcle-*-cygwin32
7396 RS/6000 AIX 4.x rs6000-*-aix4*
7400 ARM with RDP protocol arm-*-*
7401 I960 with MON960 i960-*-coff
7402 MIPS VxWorks mips*-*-vxworks*
7403 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7404 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7406 Matra Sparclet sparclet-*-*
7410 The powerpc-eabi configuration now includes the PSIM simulator,
7411 contributed by Andrew Cagney, with assistance from Mike Meissner.
7412 PSIM is a very elaborate model of the PowerPC, including not only
7413 basic instruction set execution, but also details of execution unit
7414 performance and I/O hardware. See sim/ppc/README for more details.
7418 GDB now works with Solaris 2.5.
7420 * Windows 95/NT native
7422 GDB will now work as a native debugger on Windows 95 and Windows NT.
7423 To build it from source, you must use the "gnu-win32" environment,
7424 which uses a DLL to emulate enough of Unix to run the GNU tools.
7425 Further information, binaries, and sources are available at
7426 ftp.cygnus.com, under pub/gnu-win32.
7428 * dont-repeat command
7430 If a user-defined command includes the command `dont-repeat', then the
7431 command will not be repeated if the user just types return. This is
7432 useful if the command is time-consuming to run, so that accidental
7433 extra keystrokes don't run the same command many times.
7435 * Send break instead of ^C
7437 The standard remote protocol now includes an option to send a break
7438 rather than a ^C to the target in order to interrupt it. By default,
7439 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7441 * Remote protocol timeout
7443 The standard remote protocol includes a new variable `remotetimeout'
7444 that allows you to set the number of seconds before GDB gives up trying
7445 to read from the target. The default value is 2.
7447 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7449 By default GDB will automatically keep track of objects as they are
7450 loaded and unloaded by the dynamic linker. By using the command `set
7451 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7452 when shared library events occur, thus allowing you to set breakpoints
7453 in shared libraries which are explicitly loaded by the inferior.
7455 Note this feature does not work on hpux8. On hpux9 you must link
7456 /usr/lib/end.o into your program. This feature should work
7457 automatically on hpux10.
7459 * Irix 5.x hardware watchpoint support
7461 Irix 5 configurations now support the use of hardware watchpoints.
7463 * Mips protocol "SYN garbage limit"
7465 When debugging a Mips target using the `target mips' protocol, you
7466 may set the number of characters that GDB will ignore by setting
7467 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7468 every character. The default value is 1050.
7470 * Recording and replaying remote debug sessions
7472 If you set `remotelogfile' to the name of a file, gdb will write to it
7473 a recording of a remote debug session. This recording may then be
7474 replayed back to gdb using "gdbreplay". See gdbserver/README for
7475 details. This is useful when you have a problem with GDB while doing
7476 remote debugging; you can make a recording of the session and send it
7477 to someone else, who can then recreate the problem.
7479 * Speedups for remote debugging
7481 GDB includes speedups for downloading and stepping MIPS systems using
7482 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7483 and more efficient S-record downloading.
7485 * Memory use reductions and statistics collection
7487 GDB now uses less memory and reports statistics about memory usage.
7488 Try the `maint print statistics' command, for example.
7490 *** Changes in GDB-4.15:
7492 * Psymtabs for XCOFF
7494 The symbol reader for AIX GDB now uses partial symbol tables. This
7495 can greatly improve startup time, especially for large executables.
7497 * Remote targets use caching
7499 Remote targets now use a data cache to speed up communication with the
7500 remote side. The data cache could lead to incorrect results because
7501 it doesn't know about volatile variables, thus making it impossible to
7502 debug targets which use memory mapped I/O devices. `set remotecache
7503 off' turns the data cache off.
7505 * Remote targets may have threads
7507 The standard remote protocol now includes support for multiple threads
7508 in the target system, using new protocol commands 'H' and 'T'. See
7509 gdb/remote.c for details.
7513 If GDB is configured with `--enable-netrom', then it will include
7514 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7515 acts as though it is a bank of ROM on the target board, but you can
7516 write into it over the network. GDB's support consists only of
7517 support for fast loading into the emulated ROM; to debug, you must use
7518 another protocol, such as standard remote protocol. The usual
7519 sequence is something like
7521 target nrom <netrom-hostname>
7523 target remote <netrom-hostname>:1235
7527 GDB now includes support for the Apple Macintosh, as a host only. It
7528 may be run as either an MPW tool or as a standalone application, and
7529 it can debug through the serial port. All the usual GDB commands are
7530 available, but to the target command, you must supply "serial" as the
7531 device type instead of "/dev/ttyXX". See mpw-README in the main
7532 directory for more information on how to build. The MPW configuration
7533 scripts */mpw-config.in support only a few targets, and only the
7534 mips-idt-ecoff target has been tested.
7538 GDB configuration now uses autoconf. This is not user-visible,
7539 but does simplify configuration and building.
7543 GDB now supports hpux10.
7545 *** Changes in GDB-4.14:
7547 * New native configurations
7549 x86 FreeBSD i[345]86-*-freebsd
7550 x86 NetBSD i[345]86-*-netbsd
7551 NS32k NetBSD ns32k-*-netbsd
7552 Sparc NetBSD sparc-*-netbsd
7556 A29K VxWorks a29k-*-vxworks
7557 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7558 CPU32 EST-300 emulator m68*-*-est*
7559 PowerPC ELF powerpc-*-elf
7562 * Alpha OSF/1 support for procfs
7564 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7565 possible to attach to running processes. As the mounting of the /proc
7566 filesystem is optional on the Alpha, GDB automatically determines
7567 the availability of /proc during startup. This can lead to problems
7568 if /proc is unmounted after GDB has been started.
7570 * Arguments to user-defined commands
7572 User commands may accept up to 10 arguments separated by whitespace.
7573 Arguments are accessed within the user command via $arg0..$arg9. A
7576 print $arg0 + $arg1 + $arg2
7578 To execute the command use:
7581 Defines the command "adder" which prints the sum of its three arguments.
7582 Note the arguments are text substitutions, so they may reference variables,
7583 use complex expressions, or even perform inferior function calls.
7585 * New `if' and `while' commands
7587 This makes it possible to write more sophisticated user-defined
7588 commands. Both commands take a single argument, which is the
7589 expression to evaluate, and must be followed by the commands to
7590 execute, one per line, if the expression is nonzero, the list being
7591 terminated by the word `end'. The `if' command list may include an
7592 `else' word, which causes the following commands to be executed only
7593 if the expression is zero.
7595 * Fortran source language mode
7597 GDB now includes partial support for Fortran 77. It will recognize
7598 Fortran programs and can evaluate a subset of Fortran expressions, but
7599 variables and functions may not be handled correctly. GDB will work
7600 with G77, but does not yet know much about symbols emitted by other
7603 * Better HPUX support
7605 Most debugging facilities now work on dynamic executables for HPPAs
7606 running hpux9 or later. You can attach to running dynamically linked
7607 processes, but by default the dynamic libraries will be read-only, so
7608 for instance you won't be able to put breakpoints in them. To change
7609 that behavior do the following before running the program:
7615 This will cause the libraries to be mapped private and read-write.
7616 To revert to the normal behavior, do this:
7622 You cannot set breakpoints or examine data in the library until after
7623 the library is loaded if the function/data symbols do not have
7626 GDB can now also read debug symbols produced by the HP C compiler on
7627 HPPAs (sorry, no C++, Fortran or 68k support).
7629 * Target byte order now dynamically selectable
7631 You can choose which byte order to use with a target system, via the
7632 commands "set endian big" and "set endian little", and you can see the
7633 current setting by using "show endian". You can also give the command
7634 "set endian auto", in which case GDB will use the byte order
7635 associated with the executable. Currently, only embedded MIPS
7636 configurations support dynamic selection of target byte order.
7638 * New DOS host serial code
7640 This version uses DPMI interrupts to handle buffered I/O, so you
7641 no longer need to run asynctsr when debugging boards connected to
7644 *** Changes in GDB-4.13:
7646 * New "complete" command
7648 This lists all the possible completions for the rest of the line, if it
7649 were to be given as a command itself. This is intended for use by emacs.
7651 * Trailing space optional in prompt
7653 "set prompt" no longer adds a space for you after the prompt you set. This
7654 allows you to set a prompt which ends in a space or one that does not.
7656 * Breakpoint hit counts
7658 "info break" now displays a count of the number of times the breakpoint
7659 has been hit. This is especially useful in conjunction with "ignore"; you
7660 can ignore a large number of breakpoint hits, look at the breakpoint info
7661 to see how many times the breakpoint was hit, then run again, ignoring one
7662 less than that number, and this will get you quickly to the last hit of
7665 * Ability to stop printing at NULL character
7667 "set print null-stop" will cause GDB to stop printing the characters of
7668 an array when the first NULL is encountered. This is useful when large
7669 arrays actually contain only short strings.
7671 * Shared library breakpoints
7673 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7674 breakpoints in shared libraries before the executable is run.
7676 * Hardware watchpoints
7678 There is a new hardware breakpoint for the watch command for sparclite
7679 targets. See gdb/sparclite/hw_breakpoint.note.
7681 Hardware watchpoints are also now supported under GNU/Linux.
7685 Annotations have been added. These are for use with graphical interfaces,
7686 and are still experimental. Currently only gdba.el uses these.
7688 * Improved Irix 5 support
7690 GDB now works properly with Irix 5.2.
7692 * Improved HPPA support
7694 GDB now works properly with the latest GCC and GAS.
7696 * New native configurations
7698 Sequent PTX4 i[34]86-sequent-ptx4
7699 HPPA running OSF/1 hppa*-*-osf*
7700 Atari TT running SVR4 m68*-*-sysv4*
7701 RS/6000 LynxOS rs6000-*-lynxos*
7705 OS/9000 i[34]86-*-os9k
7706 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7709 * Hitachi SH7000 and E7000-PC ICE support
7711 There is now support for communicating with the Hitachi E7000-PC ICE.
7712 This is available automatically when GDB is configured for the SH.
7716 As usual, a variety of small fixes and improvements, both generic
7717 and configuration-specific. See the ChangeLog for more detail.
7719 *** Changes in GDB-4.12:
7721 * Irix 5 is now supported
7725 GDB-4.12 on the HPPA has a number of changes which make it unable
7726 to debug the output from the currently released versions of GCC and
7727 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7728 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7729 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7732 *** Changes in GDB-4.11:
7734 * User visible changes:
7738 The "set remotedebug" option is now consistent between the mips remote
7739 target, remote targets using the gdb-specific protocol, UDI (AMD's
7740 debug protocol for the 29k) and the 88k bug monitor. It is now an
7741 integer specifying a debug level (normally 0 or 1, but 2 means more
7742 debugging info for the mips target).
7744 * DEC Alpha native support
7746 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7747 debug info, but GDB works fairly well with the DEC compiler and should
7748 work with a future GCC release. See the README file for a few
7749 Alpha-specific notes.
7751 * Preliminary thread implementation
7753 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7755 * LynxOS native and target support for 386
7757 This release has been hosted on LynxOS 2.2, and also can be configured
7758 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7761 * Improvements in C++ mangling/demangling.
7763 This release has much better g++ debugging, specifically in name
7764 mangling/demangling, virtual function calls, print virtual table,
7765 call methods, ...etc.
7767 *** Changes in GDB-4.10:
7769 * User visible changes:
7771 Remote debugging using the GDB-specific (`target remote') protocol now
7772 supports the `load' command. This is only useful if you have some
7773 other way of getting the stub to the target system, and you can put it
7774 somewhere in memory where it won't get clobbered by the download.
7776 Filename completion now works.
7778 When run under emacs mode, the "info line" command now causes the
7779 arrow to point to the line specified. Also, "info line" prints
7780 addresses in symbolic form (as well as hex).
7782 All vxworks based targets now support a user settable option, called
7783 vxworks-timeout. This option represents the number of seconds gdb
7784 should wait for responses to rpc's. You might want to use this if
7785 your vxworks target is, perhaps, a slow software simulator or happens
7786 to be on the far side of a thin network line.
7790 This release contains support for using a DEC alpha as a GDB host for
7791 cross debugging. Native alpha debugging is not supported yet.
7794 *** Changes in GDB-4.9:
7798 This is the first GDB release which is accompanied by a matching testsuite.
7799 The testsuite requires installation of dejagnu, which should be available
7800 via ftp from most sites that carry GNU software.
7804 'Cfront' style demangling has had its name changed to 'ARM' style, to
7805 emphasize that it was written from the specifications in the C++ Annotated
7806 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7807 disclaimers, it still generated too much confusion with users attempting to
7808 use gdb with AT&T cfront.
7812 GDB now uses a standard remote interface to a simulator library.
7813 So far, the library contains simulators for the Zilog Z8001/2, the
7814 Hitachi H8/300, H8/500 and Super-H.
7816 * New targets supported
7818 H8/300 simulator h8300-hitachi-hms or h8300hms
7819 H8/500 simulator h8500-hitachi-hms or h8500hms
7820 SH simulator sh-hitachi-hms or sh
7821 Z8000 simulator z8k-zilog-none or z8ksim
7822 IDT MIPS board over serial line mips-idt-ecoff
7824 Cross-debugging to GO32 targets is supported. It requires a custom
7825 version of the i386-stub.c module which is integrated with the
7826 GO32 memory extender.
7828 * New remote protocols
7830 MIPS remote debugging protocol.
7832 * New source languages supported
7834 This version includes preliminary support for Chill, a Pascal like language
7835 used by telecommunications companies. Chill support is also being integrated
7836 into the GNU compiler, but we don't know when it will be publically available.
7839 *** Changes in GDB-4.8:
7841 * HP Precision Architecture supported
7843 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7844 version of this support was available as a set of patches from the
7845 University of Utah. GDB does not support debugging of programs
7846 compiled with the HP compiler, because HP will not document their file
7847 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7848 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7850 Many problems in the preliminary version have been fixed.
7852 * Faster and better demangling
7854 We have improved template demangling and fixed numerous bugs in the GNU style
7855 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7856 character types (wchar_t) are now supported. Demangling of each symbol is now
7857 only done once, and is cached when the symbol table for a file is read in.
7858 This results in a small increase in memory usage for C programs, a moderate
7859 increase in memory usage for C++ programs, and a fantastic speedup in
7862 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7863 from the specifications in the Annotated Reference Manual, which AT&T's
7864 compiler does not actually implement.
7866 * G++ multiple inheritance compiler problem
7868 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7869 inheritance lattices was reworked to properly discover ambiguities. We
7870 recently found an example which causes this new algorithm to fail in a
7871 very subtle way, producing bad debug information for those classes.
7872 The file 'gcc.patch' (in this directory) can be applied to gcc to
7873 circumvent the problem. A future GCC release will contain a complete
7876 The previous G++ debug info problem (mentioned below for the gdb-4.7
7877 release) is fixed in gcc version 2.3.2.
7879 * Improved configure script
7881 The `configure' script will now attempt to guess your system type if
7882 you don't supply a host system type. The old scheme of supplying a
7883 host system triplet is preferable over using this. All the magic is
7884 done in the new `config.guess' script. Examine it for details.
7886 We have also brought our configure script much more in line with the FSF's
7887 version. It now supports the --with-xxx options. In particular,
7888 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7889 The resulting GDB will not be able to read arbitrary object file formats --
7890 only the format ``expected'' to be used on the configured target system.
7891 We hope to make this the default in a future release.
7893 * Documentation improvements
7895 There's new internal documentation on how to modify GDB, and how to
7896 produce clean changes to the code. We implore people to read it
7897 before submitting changes.
7899 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7900 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7901 `info' files are also provided. To build `info' files from scratch,
7902 you will need the latest `makeinfo' release, which will be available in
7903 a future texinfo-X.Y release.
7905 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7906 We're not sure exactly which versions have this problem, but it has
7907 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7908 or better. If that isn't possible, there is a patch in
7909 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7910 around this problem.
7914 GDB now supports array constants that can be used in expressions typed in by
7915 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7916 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7919 The new directory `gdb/sparclite' contains a program that demonstrates
7920 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7922 * New native hosts supported
7924 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7925 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7927 * New targets supported
7929 AMD 29k family via UDI a29k-amd-udi or udi29k
7931 * New file formats supported
7933 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7934 HPUX core files, and SCO 3.2v2 core files.
7938 Attaching to processes now works again; thanks for the many bug reports.
7940 We have also stomped on a bunch of core dumps caused by
7941 printf_filtered("%s") problems.
7943 We eliminated a copyright problem on the rpc and ptrace header files
7944 for VxWorks, which was discovered at the last minute during the 4.7
7945 release. You should now be able to build a VxWorks GDB.
7947 You can now interrupt gdb while an attached process is running. This
7948 will cause the attached process to stop, and give control back to GDB.
7950 We fixed problems caused by using too many file descriptors
7951 for reading symbols from object files and libraries. This was
7952 especially a problem for programs that used many (~100) shared
7955 The `step' command now only enters a subroutine if there is line number
7956 information for the subroutine. Otherwise it acts like the `next'
7957 command. Previously, `step' would enter subroutines if there was
7958 any debugging information about the routine. This avoids problems
7959 when using `cc -g1' on MIPS machines.
7961 * Internal improvements
7963 GDB's internal interfaces have been improved to make it easier to support
7964 debugging of multiple languages in the future.
7966 GDB now uses a common structure for symbol information internally.
7967 Minimal symbols (derived from linkage symbols in object files), partial
7968 symbols (from a quick scan of debug information), and full symbols
7969 contain a common subset of information, making it easier to write
7970 shared code that handles any of them.
7972 * New command line options
7974 We now accept --silent as an alias for --quiet.
7978 The memory-mapped-malloc library is now licensed under the GNU Library
7979 General Public License.
7981 *** Changes in GDB-4.7:
7983 * Host/native/target split
7985 GDB has had some major internal surgery to untangle the support for
7986 hosts and remote targets. Now, when you configure GDB for a remote
7987 target, it will no longer load in all of the support for debugging
7988 local programs on the host. When fully completed and tested, this will
7989 ensure that arbitrary host/target combinations are possible.
7991 The primary conceptual shift is to separate the non-portable code in
7992 GDB into three categories. Host specific code is required any time GDB
7993 is compiled on that host, regardless of the target. Target specific
7994 code relates to the peculiarities of the target, but can be compiled on
7995 any host. Native specific code is everything else: it can only be
7996 built when the host and target are the same system. Child process
7997 handling and core file support are two common `native' examples.
7999 GDB's use of /proc for controlling Unix child processes is now cleaner.
8000 It has been split out into a single module under the `target_ops' vector,
8001 plus two native-dependent functions for each system that uses /proc.
8003 * New hosts supported
8005 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8006 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8007 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8009 * New targets supported
8011 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8012 68030 and CPU32 m68030-*-*, m68332-*-*
8014 * New native hosts supported
8016 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8017 (386bsd is not well tested yet)
8018 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8020 * New file formats supported
8022 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8023 supports reading of `a.out.adobe' object files, which are an a.out
8024 format extended with minimal information about multiple sections.
8028 `show copying' is the same as the old `info copying'.
8029 `show warranty' is the same as `info warrantee'.
8030 These were renamed for consistency. The old commands continue to work.
8032 `info handle' is a new alias for `info signals'.
8034 You can now define pre-command hooks, which attach arbitrary command
8035 scripts to any command. The commands in the hook will be executed
8036 prior to the user's command. You can also create a hook which will be
8037 executed whenever the program stops. See gdb.texinfo.
8041 We now deal with Cfront style name mangling, and can even extract type
8042 info from mangled symbols. GDB can automatically figure out which
8043 symbol mangling style your C++ compiler uses.
8045 Calling of methods and virtual functions has been improved as well.
8049 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8050 fixed. This was due to mishandling of the extra N_SO stabs output
8053 We also finally got Ultrix 4.2 running in house, and fixed core file
8054 support, with help from a dozen people on the net.
8056 John M. Farrell discovered that the reason that single-stepping was so
8057 slow on all of the Mips based platforms (primarily SGI and DEC) was
8058 that we were trying to demangle and lookup a symbol used for internal
8059 purposes on every instruction that was being stepped through. Changing
8060 the name of that symbol so that it couldn't be mistaken for a C++
8061 mangled symbol sped things up a great deal.
8063 Rich Pixley sped up symbol lookups in general by getting much smarter
8064 about when C++ symbol mangling is necessary. This should make symbol
8065 completion (TAB on the command line) much faster. It's not as fast as
8066 we'd like, but it's significantly faster than gdb-4.6.
8070 A new user controllable variable 'call_scratch_address' can
8071 specify the location of a scratch area to be used when GDB
8072 calls a function in the target. This is necessary because the
8073 usual method of putting the scratch area on the stack does not work
8074 in systems that have separate instruction and data spaces.
8076 We integrated changes to support the 29k UDI (Universal Debugger
8077 Interface), but discovered at the last minute that we didn't have all
8078 of the appropriate copyright paperwork. We are working with AMD to
8079 resolve this, and hope to have it available soon.
8083 We have sped up the remote serial line protocol, especially for targets
8084 with lots of registers. It now supports a new `expedited status' ('T')
8085 message which can be used in place of the existing 'S' status message.
8086 This allows the remote stub to send only the registers that GDB
8087 needs to make a quick decision about single-stepping or conditional
8088 breakpoints, eliminating the need to fetch the entire register set for
8089 each instruction being stepped through.
8091 The GDB remote serial protocol now implements a write-through cache for
8092 registers, only re-reading the registers if the target has run.
8094 There is also a new remote serial stub for SPARC processors. You can
8095 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8096 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8097 processor with a serial port.
8101 Configure.in files have become much easier to read and modify. A new
8102 `table driven' format makes it more obvious what configurations are
8103 supported, and what files each one uses.
8107 There is a new opcodes library which will eventually contain all of the
8108 disassembly routines and opcode tables. At present, it only contains
8109 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8110 disassembler (binutils/objdump) to share these routines.
8112 The libiberty library is now copylefted under the GNU Library General
8113 Public License. This allows more liberal use, and was done so libg++
8114 can use it. This makes no difference to GDB, since the Library License
8115 grants all the rights from the General Public License.
8119 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8120 reference to the stabs symbol info used by the debugger. It is (as far
8121 as we know) the only published document on this fascinating topic. We
8122 encourage you to read it, compare it to the stabs information on your
8123 system, and send improvements on the document in general (to
8124 bug-gdb@prep.ai.mit.edu).
8126 And, of course, many bugs have been fixed.
8129 *** Changes in GDB-4.6:
8131 * Better support for C++ function names
8133 GDB now accepts as input the "demangled form" of C++ overloaded function
8134 names and member function names, and can do command completion on such names
8135 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8136 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8137 Make use of command completion, it is your friend.
8139 GDB also now accepts a variety of C++ mangled symbol formats. They are
8140 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8141 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8142 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8143 for the list of formats.
8145 * G++ symbol mangling problem
8147 Recent versions of gcc have a bug in how they emit debugging information for
8148 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8149 directory) can be applied to gcc to fix the problem. Alternatively, if you
8150 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8151 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8152 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8155 * New 'maintenance' command
8157 All of the commands related to hacking GDB internals have been moved out of
8158 the main command set, and now live behind the 'maintenance' command. This
8159 can also be abbreviated as 'mt'. The following changes were made:
8161 dump-me -> maintenance dump-me
8162 info all-breakpoints -> maintenance info breakpoints
8163 printmsyms -> maintenance print msyms
8164 printobjfiles -> maintenance print objfiles
8165 printpsyms -> maintenance print psymbols
8166 printsyms -> maintenance print symbols
8168 The following commands are new:
8170 maintenance demangle Call internal GDB demangler routine to
8171 demangle a C++ link name and prints the result.
8172 maintenance print type Print a type chain for a given symbol
8174 * Change to .gdbinit file processing
8176 We now read the $HOME/.gdbinit file before processing the argv arguments
8177 (e.g. reading symbol files or core files). This allows global parameters to
8178 be set, which will apply during the symbol reading. The ./.gdbinit is still
8179 read after argv processing.
8181 * New hosts supported
8183 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8185 GNU/Linux support i386-unknown-linux or linux
8187 We are also including code to support the HP/PA running BSD and HPUX. This
8188 is almost guaranteed not to work, as we didn't have time to test or build it
8189 for this release. We are including it so that the more adventurous (or
8190 masochistic) of you can play with it. We also had major problems with the
8191 fact that the compiler that we got from HP doesn't support the -g option.
8194 * New targets supported
8196 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8198 * More smarts about finding #include files
8200 GDB now remembers the compilation directory for all include files, and for
8201 all files from which C is generated (like yacc and lex sources). This
8202 greatly improves GDB's ability to find yacc/lex sources, and include files,
8203 especially if you are debugging your program from a directory different from
8204 the one that contains your sources.
8206 We also fixed a bug which caused difficulty with listing and setting
8207 breakpoints in include files which contain C code. (In the past, you had to
8208 try twice in order to list an include file that you hadn't looked at before.)
8210 * Interesting infernals change
8212 GDB now deals with arbitrary numbers of sections, where the symbols for each
8213 section must be relocated relative to that section's landing place in the
8214 target's address space. This work was needed to support ELF with embedded
8215 stabs used by Solaris-2.0.
8217 * Bug fixes (of course!)
8219 There have been loads of fixes for the following things:
8220 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8221 i960, stabs, DOS(GO32), procfs, etc...
8223 See the ChangeLog for details.
8225 *** Changes in GDB-4.5:
8227 * New machines supported (host and target)
8229 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8231 SGI Irix-4.x mips-sgi-irix4 or iris4
8233 * New malloc package
8235 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8236 Mmalloc is capable of handling multiple heaps of memory. It is also
8237 capable of saving a heap to a file, and then mapping it back in later.
8238 This can be used to greatly speedup the startup of GDB by using a
8239 pre-parsed symbol table which lives in a mmalloc managed heap. For
8240 more details, please read mmalloc/mmalloc.texi.
8244 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8245 'help info proc' for details.
8247 * MIPS ecoff symbol table format
8249 The code that reads MIPS symbol table format is now supported on all hosts.
8250 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8253 * File name changes for MS-DOS
8255 Many files in the config directories have been renamed to make it easier to
8256 support GDB on MS-DOSe systems (which have very restrictive file name
8257 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8258 environment) is close to working but has some remaining problems. Note
8259 that debugging of DOS programs is not supported, due to limitations
8260 in the ``operating system'', but it can be used to host cross-debugging.
8262 * Cross byte order fixes
8264 Many fixes have been made to support cross debugging of Sparc and MIPS
8265 targets from hosts whose byte order differs.
8267 * New -mapped and -readnow options
8269 If memory-mapped files are available on your system through the 'mmap'
8270 system call, you can use the -mapped option on the `file' or
8271 `symbol-file' commands to cause GDB to write the symbols from your
8272 program into a reusable file. If the program you are debugging is
8273 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8274 Future GDB debugging sessions will notice the presence of this file,
8275 and will quickly map in symbol information from it, rather than reading
8276 the symbol table from the executable program. Using the '-mapped'
8277 option in a GDB `file' or `symbol-file' command has the same effect as
8278 starting GDB with the '-mapped' command-line option.
8280 You can cause GDB to read the entire symbol table immediately by using
8281 the '-readnow' option with any of the commands that load symbol table
8282 information (or on the GDB command line). This makes the command
8283 slower, but makes future operations faster.
8285 The -mapped and -readnow options are typically combined in order to
8286 build a `fred.syms' file that contains complete symbol information.
8287 A simple GDB invocation to do nothing but build a `.syms' file for future
8290 gdb -batch -nx -mapped -readnow programname
8292 The `.syms' file is specific to the host machine on which GDB is run.
8293 It holds an exact image of GDB's internal symbol table. It cannot be
8294 shared across multiple host platforms.
8296 * longjmp() handling
8298 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8299 siglongjmp() without losing control. This feature has not yet been ported to
8300 all systems. It currently works on many 386 platforms, all MIPS-based
8301 platforms (SGI, DECstation, etc), and Sun3/4.
8305 Preliminary work has been put in to support the new Solaris OS from Sun. At
8306 this time, it can control and debug processes, but it is not capable of
8311 As always, many many bug fixes. The major areas were with g++, and mipsread.
8312 People using the MIPS-based platforms should experience fewer mysterious
8313 crashes and trashed symbol tables.
8315 *** Changes in GDB-4.4:
8317 * New machines supported (host and target)
8319 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8321 BSD Reno on Vax vax-dec-bsd
8322 Ultrix on Vax vax-dec-ultrix
8324 * New machines supported (target)
8326 AMD 29000 embedded, using EBMON a29k-none-none
8330 GDB continues to improve its handling of C++. `References' work better.
8331 The demangler has also been improved, and now deals with symbols mangled as
8332 per the Annotated C++ Reference Guide.
8334 GDB also now handles `stabs' symbol information embedded in MIPS
8335 `ecoff' symbol tables. Since the ecoff format was not easily
8336 extensible to handle new languages such as C++, this appeared to be a
8337 good way to put C++ debugging info into MIPS binaries. This option
8338 will be supported in the GNU C compiler, version 2, when it is
8341 * New features for SVR4
8343 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8344 shared libraries. Debugging dynamically linked programs should present
8345 only minor differences from debugging statically linked programs.
8347 The `info proc' command will print out information about any process
8348 on an SVR4 system (including the one you are debugging). At the moment,
8349 it prints the address mappings of the process.
8351 If you bring up GDB on another SVR4 system, please send mail to
8352 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8354 * Better dynamic linking support in SunOS
8356 Reading symbols from shared libraries which contain debugging symbols
8357 now works properly. However, there remain issues such as automatic
8358 skipping of `transfer vector' code during function calls, which
8359 make it harder to debug code in a shared library, than to debug the
8360 same code linked statically.
8364 GDB is now using the latest `getopt' routines from the FSF. This
8365 version accepts the -- prefix for options with long names. GDB will
8366 continue to accept the old forms (-option and +option) as well.
8367 Various single letter abbreviations for options have been explicity
8368 added to the option table so that they won't get overshadowed in the
8369 future by other options that begin with the same letter.
8373 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8374 Many assorted bugs have been handled. Many more remain to be handled.
8375 See the various ChangeLog files (primarily in gdb and bfd) for details.
8378 *** Changes in GDB-4.3:
8380 * New machines supported (host and target)
8382 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8383 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8384 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8386 * Almost SCO Unix support
8388 We had hoped to support:
8389 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8390 (except for core file support), but we discovered very late in the release
8391 that it has problems with process groups that render gdb unusable. Sorry
8392 about that. I encourage people to fix it and post the fixes.
8394 * Preliminary ELF and DWARF support
8396 GDB can read ELF object files on System V Release 4, and can handle
8397 debugging records for C, in DWARF format, in ELF files. This support
8398 is preliminary. If you bring up GDB on another SVR4 system, please
8399 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8404 GDB now uses the latest `readline' library. One user-visible change
8405 is that two tabs will list possible command completions, which previously
8406 required typing M-? (meta-question mark, or ESC ?).
8410 The `stepi' bug that many of you noticed has been squashed.
8411 Many bugs in C++ have been handled. Many more remain to be handled.
8412 See the various ChangeLog files (primarily in gdb and bfd) for details.
8414 * State of the MIPS world (in case you wondered):
8416 GDB can understand the symbol tables emitted by the compilers
8417 supplied by most vendors of MIPS-based machines, including DEC. These
8418 symbol tables are in a format that essentially nobody else uses.
8420 Some versions of gcc come with an assembler post-processor called
8421 mips-tfile. This program is required if you want to do source-level
8422 debugging of gcc-compiled programs. I believe FSF does not ship
8423 mips-tfile with gcc version 1, but it will eventually come with gcc
8426 Debugging of g++ output remains a problem. g++ version 1.xx does not
8427 really support it at all. (If you're lucky, you should be able to get
8428 line numbers and stack traces to work, but no parameters or local
8429 variables.) With some work it should be possible to improve the
8432 When gcc version 2 is released, you will have somewhat better luck.
8433 However, even then you will get confusing results for inheritance and
8436 We will eventually provide full debugging of g++ output on
8437 DECstations. This will probably involve some kind of stabs-in-ecoff
8438 encapulation, but the details have not been worked out yet.
8441 *** Changes in GDB-4.2:
8443 * Improved configuration
8445 Only one copy of `configure' exists now, and it is not self-modifying.
8446 Porting BFD is simpler.
8450 The `step' and `next' commands now only stop at the first instruction
8451 of a source line. This prevents the multiple stops that used to occur
8452 in switch statements, for-loops, etc. `Step' continues to stop if a
8453 function that has debugging information is called within the line.
8457 Lots of small bugs fixed. More remain.
8459 * New host supported (not target)
8461 Intel 386 PC clone running Mach i386-none-mach
8464 *** Changes in GDB-4.1:
8466 * Multiple source language support
8468 GDB now has internal scaffolding to handle several source languages.
8469 It determines the type of each source file from its filename extension,
8470 and will switch expression parsing and number formatting to match the
8471 language of the function in the currently selected stack frame.
8472 You can also specifically set the language to be used, with
8473 `set language c' or `set language modula-2'.
8477 GDB now has preliminary support for the GNU Modula-2 compiler,
8478 currently under development at the State University of New York at
8479 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8480 continue through the fall of 1991 and into 1992.
8482 Other Modula-2 compilers are currently not supported, and attempting to
8483 debug programs compiled with them will likely result in an error as the
8484 symbol table is read. Feel free to work on it, though!
8486 There are hooks in GDB for strict type checking and range checking,
8487 in the `Modula-2 philosophy', but they do not currently work.
8491 GDB can now write to executable and core files (e.g. patch
8492 a variable's value). You must turn this switch on, specify
8493 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8494 by assigning a new value to a variable. Modifications take
8497 * Automatic SunOS shared library reading
8499 When you run your program, GDB automatically determines where its
8500 shared libraries (if any) have been loaded, and reads their symbols.
8501 The `share' command is no longer needed. This also works when
8502 examining core files.
8506 You can specify the number of lines that the `list' command shows.
8509 * New machines supported (host and target)
8511 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8512 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8513 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8515 * New hosts supported (not targets)
8517 IBM RT/PC: romp-ibm-aix or rtpc
8519 * New targets supported (not hosts)
8521 AMD 29000 embedded with COFF a29k-none-coff
8522 AMD 29000 embedded with a.out a29k-none-aout
8523 Ultracomputer remote kernel debug a29k-nyu-kern
8525 * New remote interfaces
8531 *** Changes in GDB-4.0:
8535 Wide output is wrapped at good places to make the output more readable.
8537 Gdb now supports cross-debugging from a host machine of one type to a
8538 target machine of another type. Communication with the target system
8539 is over serial lines. The ``target'' command handles connecting to the
8540 remote system; the ``load'' command will download a program into the
8541 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8542 also supports debugging of realtime processes running under VxWorks,
8543 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8544 stub on the target system.
8546 New CPUs supported include the AMD 29000 and Intel 960.
8548 GDB now reads object files and symbol tables via a ``binary file''
8549 library, which allows a single copy of GDB to debug programs of multiple
8550 object file types such as a.out and coff.
8552 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8553 refcard.dvi and refcard.ps are available to format it).
8556 * Control-Variable user interface simplified
8558 All variables that control the operation of the debugger can be set
8559 by the ``set'' command, and displayed by the ``show'' command.
8561 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8562 ``Show prompt'' produces the response:
8563 Gdb's prompt is new-gdb=>.
8565 What follows are the NEW set commands. The command ``help set'' will
8566 print a complete list of old and new set commands. ``help set FOO''
8567 will give a longer description of the variable FOO. ``show'' will show
8568 all of the variable descriptions and their current settings.
8570 confirm on/off: Enables warning questions for operations that are
8571 hard to recover from, e.g. rerunning the program while
8572 it is already running. Default is ON.
8574 editing on/off: Enables EMACS style command line editing
8575 of input. Previous lines can be recalled with
8576 control-P, the current line can be edited with control-B,
8577 you can search for commands with control-R, etc.
8580 history filename NAME: NAME is where the gdb command history
8581 will be stored. The default is .gdb_history,
8582 or the value of the environment variable
8585 history size N: The size, in commands, of the command history. The
8586 default is 256, or the value of the environment variable
8589 history save on/off: If this value is set to ON, the history file will
8590 be saved after exiting gdb. If set to OFF, the
8591 file will not be saved. The default is OFF.
8593 history expansion on/off: If this value is set to ON, then csh-like
8594 history expansion will be performed on
8595 command line input. The default is OFF.
8597 radix N: Sets the default radix for input and output. It can be set
8598 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8599 in the current radix, so "set radix 10" is always a no-op.
8601 height N: This integer value is the number of lines on a page. Default
8602 is 24, the current `stty rows'' setting, or the ``li#''
8603 setting from the termcap entry matching the environment
8606 width N: This integer value is the number of characters on a line.
8607 Default is 80, the current `stty cols'' setting, or the ``co#''
8608 setting from the termcap entry matching the environment
8611 Note: ``set screensize'' is obsolete. Use ``set height'' and
8612 ``set width'' instead.
8614 print address on/off: Print memory addresses in various command displays,
8615 such as stack traces and structure values. Gdb looks
8616 more ``symbolic'' if you turn this off; it looks more
8617 ``machine level'' with it on. Default is ON.
8619 print array on/off: Prettyprint arrays. New convenient format! Default
8622 print demangle on/off: Print C++ symbols in "source" form if on,
8625 print asm-demangle on/off: Same, for assembler level printouts
8628 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8631 * Support for Epoch Environment.
8633 The epoch environment is a version of Emacs v18 with windowing. One
8634 new command, ``inspect'', is identical to ``print'', except that if you
8635 are running in the epoch environment, the value is printed in its own
8639 * Support for Shared Libraries
8641 GDB can now debug programs and core files that use SunOS shared libraries.
8642 Symbols from a shared library cannot be referenced
8643 before the shared library has been linked with the program (this
8644 happens after you type ``run'' and before the function main() is entered).
8645 At any time after this linking (including when examining core files
8646 from dynamically linked programs), gdb reads the symbols from each
8647 shared library when you type the ``sharedlibrary'' command.
8648 It can be abbreviated ``share''.
8650 sharedlibrary REGEXP: Load shared object library symbols for files
8651 matching a unix regular expression. No argument
8652 indicates to load symbols for all shared libraries.
8654 info sharedlibrary: Status of loaded shared libraries.
8659 A watchpoint stops execution of a program whenever the value of an
8660 expression changes. Checking for this slows down execution
8661 tremendously whenever you are in the scope of the expression, but is
8662 quite useful for catching tough ``bit-spreader'' or pointer misuse
8663 problems. Some machines such as the 386 have hardware for doing this
8664 more quickly, and future versions of gdb will use this hardware.
8666 watch EXP: Set a watchpoint (breakpoint) for an expression.
8668 info watchpoints: Information about your watchpoints.
8670 delete N: Deletes watchpoint number N (same as breakpoints).
8671 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8672 enable N: Re-enables watchpoint number N (same as breakpoints).
8675 * C++ multiple inheritance
8677 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8680 * C++ exception handling
8682 Gdb now supports limited C++ exception handling. Besides the existing
8683 ability to breakpoint on an exception handler, gdb can breakpoint on
8684 the raising of an exception (before the stack is peeled back to the
8687 catch FOO: If there is a FOO exception handler in the dynamic scope,
8688 set a breakpoint to catch exceptions which may be raised there.
8689 Multiple exceptions (``catch foo bar baz'') may be caught.
8691 info catch: Lists all exceptions which may be caught in the
8692 current stack frame.
8695 * Minor command changes
8697 The command ``call func (arg, arg, ...)'' now acts like the print
8698 command, except it does not print or save a value if the function's result
8699 is void. This is similar to dbx usage.
8701 The ``up'' and ``down'' commands now always print the frame they end up
8702 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8703 frames without printing.
8705 * New directory command
8707 'dir' now adds directories to the FRONT of the source search path.
8708 The path starts off empty. Source files that contain debug information
8709 about the directory in which they were compiled can be found even
8710 with an empty path; Sun CC and GCC include this information. If GDB can't
8711 find your source file in the current directory, type "dir .".
8713 * Configuring GDB for compilation
8715 For normal use, type ``./configure host''. See README or gdb.texinfo
8718 GDB now handles cross debugging. If you are remotely debugging between
8719 two different machines, type ``./configure host -target=targ''.
8720 Host is the machine where GDB will run; targ is the machine
8721 where the program that you are debugging will run.