1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 12
6 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
9 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
11 * Remove support for building against Python 2, it is now only possible to
12 build GDB against Python 3.
14 * DBX mode has been removed.
16 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
17 emit to indicate where a breakpoint should be placed to break in a function
22 maintenance set ignore-prologue-end-flag on|off
23 maintenance show ignore-prologue-end-flag
24 This setting, which is off by default, controls whether GDB ignores the
25 PROLOGUE-END flag from the line-table when skipping prologue. This can be
26 used to force GDB to use prologue analyzers if the line-table is constructed
27 from erroneous debug information.
31 maintenance info line-table
32 Add a PROLOGUE-END column to the output which indicates that an
33 entry corresponds to an address where a breakpoint should be placed
34 to be at the first instruction past a function's prologue.
38 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
39 that formats ADDRESS as 'address <symbol+offset>', where symbol is
40 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
41 This is the same format that GDB uses when printing address, symbol,
42 and offset information from the disassembler.
46 * DBX mode is deprecated, and will be removed in GDB 13
48 * GDB 12 is the last release of GDB that will support building against
49 Python 2. From GDB 13, it will only be possible to build GDB itself
50 with Python 3 support.
52 * Improved C++ template support
54 GDB now treats functions/types involving C++ templates like it does function
55 overloads. Users may omit parameter lists to set breakpoints on families of
56 template functions, including types/functions composed of multiple template types:
58 (gdb) break template_func(template_1, int)
60 The above will set breakpoints at every function `template_func' where
61 the first function parameter is any template type named `template_1' and
62 the second function parameter is `int'.
64 TAB completion also gains similar improvements.
66 * The FreeBSD native target now supports async mode.
72 Enable or disable multithreaded symbol loading. This is enabled
73 by default, but passing --disable-threading or --enable-threading=no
74 to configure will disable it.
76 Disabling this can cause a performance penalty when there are a lot of
77 symbols to load, but is useful for debugging purposes.
81 maint set backtrace-on-fatal-signal on|off
82 maint show backtrace-on-fatal-signal
83 This setting is 'on' by default. When 'on' GDB will print a limited
84 backtrace to stderr in the situation where GDB terminates with a
85 fatal signal. This only supported on some platforms where the
86 backtrace and backtrace_symbols_fd functions are available.
88 set source open on|off
90 This setting, which is on by default, controls whether GDB will try
91 to open source code files. Switching this off will stop GDB trying
92 to open and read source code files, which can be useful if the files
93 are located over a slow network connection.
97 These are now deprecated aliases for "set max-value-size" and
98 "show max-value-size".
100 task apply [all | TASK-IDS...] [FLAG]... COMMAND
101 Like "thread apply", but applies COMMAND to Ada tasks.
104 Watchpoints can now be restricted to a specific Ada task.
106 maint set internal-error backtrace on|off
107 maint show internal-error backtrace
108 maint set internal-warning backtrace on|off
109 maint show internal-warning backtrace
110 GDB can now print a backtrace of itself when it encounters either an
111 internal-error, or an internal-warning. This is on by default for
112 internal-error and off by default for internal-warning.
115 Deprecated and replaced by "set logging enabled on|off".
117 set logging enabled on|off
119 These commands set or show whether logging is enabled or disabled.
122 You can now exit GDB by using the new command "exit", in addition to
123 the existing "quit" command.
125 set debug threads on|off
127 Print additional debug messages about thread creation and deletion.
129 set debug linux-nat on|off
131 These new commands replaced the old 'set debug lin-lwp' and 'show
132 debug lin-lwp' respectively. Turning this setting on prints debug
133 messages relating to GDB's handling of native Linux inferiors.
135 maint flush source-cache
136 Flush the contents of the source code cache.
138 maint set gnu-source-highlight enabled on|off
139 maint show gnu-source-highlight enabled
140 Whether GDB should use the GNU Source Highlight library for adding
141 styling to source code. When off, the library will not be used, even
142 when available. When GNU Source Highlight isn't used, or can't add
143 styling to a particular source file, then the Python Pygments
144 library will be used instead.
146 set suppress-cli-notifications (on|off)
147 show suppress-cli-notifications
148 This controls whether printing the notifications is suppressed for CLI.
149 CLI notifications occur when you change the selected context
150 (i.e., the current inferior, thread and/or the frame), or when
151 the program being debugged stops (e.g., because of hitting a
152 breakpoint, completing source-stepping, an interrupt, etc.).
154 set style disassembler enabled on|off
155 show style disassembler enabled
156 If GDB is compiled with Python support, and the Python Pygments
157 package is available, then, when this setting is on, disassembler
158 output will have styling applied.
160 set ada source-charset
161 show ada source-charset
162 Set the character set encoding that is assumed for Ada symbols. Valid
163 values for this follow the values that can be passed to the GNAT
164 compiler via the '-gnati' option. The default is ISO-8859-1.
170 These are the new names for the old 'layout', 'focus', 'refresh',
171 and 'winheight' tui commands respectively. The old names still
172 exist as aliases to these new commands.
176 The new command 'tui window width', and the alias 'winwidth' allow
177 the width of a tui window to be adjusted when windows are laid out
182 Control the display of debug output about GDB's tui.
187 Printing of floating-point values with base-modifying formats like
188 /x has been changed to display the underlying bytes of the value in
189 the desired base. This was GDB's documented behavior, but was never
190 implemented correctly.
193 This command can now print a reply, if the reply includes
194 non-printable characters. Any non-printable characters are printed
195 as escaped hex, e.g. \x?? where '??' is replaces with the value of
196 the non-printable character.
199 The clone-inferior command now ensures that the TTY, CMD and ARGS
200 settings are copied from the original inferior to the new one.
201 All modifications to the environment variables done using the 'set
202 environment' or 'unset environment' commands are also copied to the new
205 set debug lin-lwp on|off
207 These commands have been removed from GDB. The new command 'set
208 debug linux-nat' and 'show debug linux-nat' should be used
212 This command now includes information about the width of the tui
213 windows in its output.
219 These commands are now aliases for the 'tui layout', 'tui focus',
220 'tui refresh', and 'tui window height' commands respectively.
222 * GDB's Ada parser now supports an extension for specifying the exact
223 byte contents of a floating-point literal. This can be useful for
224 setting floating-point registers to a precise value without loss of
225 precision. The syntax is an extension of the based literal syntax.
226 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
227 of the floating-point type, and the "f" is the marker for floating
232 ** The '-add-inferior' with no option flags now inherits the
233 connection of the current inferior, this restores the behaviour of
234 GDB as it was prior to GDB 10.
236 ** The '-add-inferior' command now accepts a '--no-connection'
237 option, which causes the new inferior to start without a
242 GNU/Linux/LoongArch loongarch*-*-linux*
250 ** New function gdb.add_history(), which takes a gdb.Value object
251 and adds the value it represents to GDB's history list. An
252 integer, the index of the new item in the history list, is
255 ** New function gdb.history_count(), which returns the number of
256 values in GDB's value history.
258 ** New gdb.events.gdb_exiting event. This event is called with a
259 gdb.GdbExitingEvent object which has the read-only attribute
260 'exit_code', which contains the value of the GDB exit code. This
261 event is triggered once GDB decides it is going to exit, but
262 before GDB starts to clean up its internal state.
264 ** New function gdb.architecture_names(), which returns a list
265 containing all of the possible Architecture.name() values. Each
268 ** New function gdb.Architecture.integer_type(), which returns an
269 integer type given a size and a signed-ness.
271 ** New gdb.TargetConnection object type that represents a connection
272 (as displayed by the 'info connections' command). A sub-class,
273 gdb.RemoteTargetConnection, is used to represent 'remote' and
274 'extended-remote' connections.
276 ** The gdb.Inferior type now has a 'connection' property which is an
277 instance of gdb.TargetConnection, the connection used by this
278 inferior. This can be None if the inferior has no connection.
280 ** New 'gdb.events.connection_removed' event registry, which emits a
281 'gdb.ConnectionEvent' when a connection is removed from GDB.
282 This event has a 'connection' property, a gdb.TargetConnection
283 object for the connection being removed.
285 ** New gdb.connections() function that returns a list of all
286 currently active connections.
288 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
289 is equivalent to the existing 'maint packet' CLI command; it
290 allows a user specified packet to be sent to the remote target.
292 ** New function gdb.host_charset(), returns a string, which is the
293 name of the current host charset.
295 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
298 ** New gdb.with_parameter(NAME, VALUE). This returns a context
299 manager that temporarily sets the gdb parameter NAME to VALUE,
300 then resets it when the context is exited.
302 ** The gdb.Value.format_string method now takes a 'styling'
303 argument, which is a boolean. When true, the returned string can
304 include escape sequences to apply styling. The styling will only
305 be present if styling is otherwise turned on in GDB (see 'help
306 set styling'). When false, which is the default if the argument
307 is not given, then no styling is applied to the returned string.
309 ** New read-only attribute gdb.InferiorThread.details, which is
310 either a string, containing additional, target specific thread
311 state information, or None, if there is no such additional
314 ** New read-only attribute gdb.Type.is_scalar, which is True for
315 scalar types, and False for all other types.
317 ** New read-only attribute gdb.Type.is_signed. This attribute
318 should only be read when Type.is_scalar is True, and will be True
319 for signed types, and False for all other types. Attempting to
320 read this attribute for non-scalar types will raise a ValueError.
322 ** It is now possible to add GDB/MI commands implemented in Python.
324 * New features in the GDB remote stub, GDBserver
326 ** GDBserver is now supported on OpenRISC GNU/Linux.
328 * New native configurations
330 GNU/Linux/OpenRISC or1k*-*-linux*
332 *** Changes in GDB 11
334 * The 'set disassembler-options' command now supports specifying options
337 * GDB now supports general memory tagging functionality if the underlying
338 architecture supports the proper primitives and hooks. Currently this is
339 enabled only for AArch64 MTE.
343 - Additional information when the inferior crashes with a SIGSEGV caused by
344 a memory tag violation.
346 - A new modifier 'm' for the "x" command, which displays allocation tags for a
347 particular memory range.
349 - Display of memory tag mismatches by "print", for addresses and
350 pointers, if memory tagging is supported by the architecture.
352 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
357 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
359 The MI -break-insert and -dprintf-insert commands now support a
360 new "--qualified" option that makes GDB interpret a specified
361 function name as a complete fully-qualified name. This is the
362 equivalent of the CLI's "break -qualified" and "dprintf
365 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
367 The MI -break-insert and -dprintf-insert commands now support a
368 '--force-condition' flag to forcibly define a condition even when
369 the condition is invalid at all locations of the breakpoint. This
370 is equivalent to the '-force-condition' flag of the CLI's "break"
373 ** '-break-condition --force'
375 The MI -break-condition command now supports a '--force' flag to
376 forcibly define a condition even when the condition is invalid at
377 all locations of the selected breakpoint. This is equivalent to
378 the '-force' flag of the CLI's "cond" command.
380 ** '-file-list-exec-source-files [--group-by-objfile]
381 [--basename | --dirname]
384 The existing -file-list-exec-source-files command now takes an
385 optional REGEXP which is used to filter the source files that are
386 included in the results.
388 By default REGEXP is matched against the full filename of the
389 source file. When one of --basename or --dirname is given then
390 REGEXP is only matched against the specified part of the full
393 When the optional --group-by-objfile flag is used the output
394 format is changed, the results are now a list of object files
395 (executable and libraries) with the source files that are
396 associated with each object file.
398 The results from -file-list-exec-source-files now include a
399 'debug-fully-read' field which takes the value 'true' or 'false'.
400 A 'true' value indicates the source file is from a compilation
401 unit that has had its debug information fully read in by GDB, a
402 value of 'false' indicates GDB has only performed a partial scan
403 of the debug information so far.
405 * GDB now supports core file debugging for x86_64 Cygwin programs.
407 * GDB will now look for the .gdbinit file in a config directory before
408 looking for ~/.gdbinit. The file is searched for in the following
409 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
410 $HOME/.gdbinit. On Apple hosts the search order is instead:
411 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
413 * GDB now supports fixed point types which are described in DWARF
414 as base types with a fixed-point encoding. Additionally, support
415 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
418 For Ada, this allows support for fixed point types without requiring
419 the use of the GNAT encoding (based on information added to the type's
420 name following a GNAT-specific format).
422 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
423 or ~/.gdbearlyinit if these files are present. These files are
424 processed earlier than any of the other initialization files and
425 can affect parts of GDB's startup that previously had already been
426 completed before the initialization files were read, for example
427 styling of the initial GDB greeting.
429 * GDB now has two new options "--early-init-command" and
430 "--early-init-eval-command" with corresponding short options "-eix"
431 and "-eiex" that allow options (that would normally appear in a
432 gdbearlyinit file) to be passed on the command line.
434 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
435 now understood by GDB, and can be used to describe the vector
436 registers of a target. The precise requirements of this register
437 feature are documented in the GDB manual.
439 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
440 supported by GDB and describes a new VPR register from the ARM MVE
441 (Helium) extension. See the GDB manual for more information.
445 ** TUI windows now support mouse actions. The mouse wheel scrolls
446 the appropriate window.
448 ** Key combinations that do not have a specific action on the
449 focused window are passed to GDB. For example, you now can use
450 Ctrl-Left/Ctrl-Right to move between words in the command window
451 regardless of which window is in focus. Previously you would
452 need to focus on the command window for such key combinations to
458 show debug event-loop
459 Control the display of debug output about GDB's event loop.
461 set print memory-tag-violations
462 show print memory-tag-violations
463 Control whether to display additional information about memory tag violations
464 when printing pointers and addresses. Architecture support for memory
465 tagging is required for this option to have an effect.
467 maintenance flush symbol-cache
468 maintenance flush register-cache
469 These new commands are equivalent to the already existing commands
470 'maintenance flush-symbol-cache' and 'flushregs' respectively.
472 maintenance flush dcache
473 A new command to flush the dcache.
475 maintenance info target-sections
476 Print GDB's internal target sections table.
479 Print the JIT code objects in the inferior known to GDB.
481 memory-tag show-logical-tag POINTER
482 Print the logical tag for POINTER.
483 memory-tag with-logical-tag POINTER TAG
484 Print POINTER with logical tag TAG.
485 memory-tag show-allocation-tag ADDRESS
486 Print the allocation tag for ADDRESS.
487 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
488 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
489 memory-tag check POINTER
490 Validate that POINTER's logical tag matches the allocation tag.
492 set startup-quietly on|off
494 When 'on', this causes GDB to act as if "-silent" were passed on the
495 command line. This command needs to be added to an early
496 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
499 set print type hex on|off
501 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
502 and offsets of struct members. When 'off', decimal notation is used.
504 set python ignore-environment on|off
505 show python ignore-environment
506 When 'on', this causes GDB's builtin Python to ignore any
507 environment variables that would otherwise affect how Python
508 behaves. This command needs to be added to an early initialization
509 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
511 set python dont-write-bytecode auto|on|off
512 show python dont-write-bytecode
513 When 'on', this causes GDB's builtin Python to not write any
514 byte-code (.pyc files) to disk. This command needs to be added to
515 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
516 order to affect GDB. When 'off' byte-code will always be written.
517 When set to 'auto' (the default) Python will check the
518 PYTHONDONTWRITEBYTECODE environment variable.
522 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
523 [-force-condition] [if CONDITION]
524 This command would previously refuse setting a breakpoint if the
525 CONDITION expression is invalid at a location. It now accepts and
526 defines the breakpoint if there is at least one location at which
527 the CONDITION is valid. The locations for which the CONDITION is
528 invalid, are automatically disabled. If CONDITION is invalid at all
529 of the locations, setting the breakpoint is still rejected. However,
530 the '-force-condition' flag can be used in this case for forcing GDB to
531 define the breakpoint, making all the current locations automatically
532 disabled. This may be useful if the user knows the condition will
533 become meaningful at a future location, e.g. due to a shared library
536 condition [-force] N COND
537 The behavior of this command is changed the same way for the 'break'
538 command as explained above. The '-force' flag can be used to force
539 GDB into defining the condition even when COND is invalid for all the
540 current locations of breakpoint N.
543 maintenance flush-symbol-cache
544 These commands are deprecated in favor of the new commands
545 'maintenance flush register-cache' and 'maintenance flush
546 symbol-cache' respectively.
548 set style version foreground COLOR
549 set style version background COLOR
550 set style version intensity VALUE
551 Control the styling of GDB's version number text.
554 When the ID parameter is omitted, then this command prints information
555 about the current inferior. When the ID parameter is present, the
556 behavior of the command is unchanged and have the inferior ID become
557 the current inferior.
559 maintenance info sections
560 The ALLOBJ keyword has been replaced with an -all-objects command
561 line flag. It is now possible to filter which sections are printed
562 even when -all-objects is passed.
564 ptype[/FLAGS] TYPE | EXPRESSION
565 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
566 notation is used when printing sizes and offsets of struct members.
567 When '/d' is set, decimal notation is used when printing sizes and
568 offsets of struct members. Default behavior is given by 'show print
572 The info sources command output has been restructured. The results
573 are now based around a list of objfiles (executable and libraries),
574 and for each objfile the source files that are part of that objfile
577 * Removed targets and native configurations
579 ARM Symbian arm*-*-symbianelf*
584 Request the remote to send allocation tags for a particular memory range.
586 Request the remote to store the specified allocation tags to the requested
591 ** Improved support for rvalue reference values:
592 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
593 value-referenced-value procedure now handles rvalue reference
596 ** New procedures for obtaining value variants:
597 value-reference-value, value-rvalue-reference-value and
600 ** Temporary breakpoints can now be created with make-breakpoint and
601 tested for using breakpoint-temporary?.
605 ** Inferior objects now contain a read-only 'connection_num' attribute that
606 gives the connection number as seen in 'info connections' and
609 ** New method gdb.Frame.level() which returns the stack level of the
612 ** New method gdb.PendingFrame.level() which returns the stack level
615 ** When hitting a catchpoint, the Python API will now emit a
616 gdb.BreakpointEvent rather than a gdb.StopEvent. The
617 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
619 ** Python TUI windows can now receive mouse click events. If the
620 Window object implements the click method, it is called for each
621 mouse click event in this window.
623 *** Changes in GDB 10
625 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
626 and "org.gnu.gdb.arc.aux". The old names are still supported but
627 must be considered obsolete. They will be deprecated after some
630 * Help and apropos commands will now show the documentation of a
631 command only once, even if that command has one or more aliases.
632 These commands now show the command name, then all of its aliases,
633 and finally the description of the command.
635 * 'help aliases' now shows only the user defined aliases. GDB predefined
636 aliases are shown together with their aliased command.
638 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
639 debugging information as well as source code.
641 When built with debuginfod, GDB can automatically query debuginfod
642 servers for the separate debug files and source code of the executable
645 To build GDB with debuginfod, pass --with-debuginfod to configure (this
646 requires libdebuginfod, the debuginfod client library).
648 debuginfod is distributed with elfutils, starting with version 0.178.
650 You can get the latest version from https://sourceware.org/elfutils.
652 * Multi-target debugging support
654 GDB now supports debugging multiple target connections
655 simultaneously. For example, you can now have each inferior
656 connected to different remote servers running in different machines,
657 or have one inferior debugging a local native process, an inferior
658 debugging a core dump, etc.
660 This support is experimental and comes with some limitations -- you
661 can only resume multiple targets simultaneously if all targets
662 support non-stop mode, and all remote stubs or servers must support
663 the same set of remote protocol features exactly. See also "info
664 connections" and "add-inferior -no-connection" below, and "maint set
665 target-non-stop" in the user manual.
667 * New features in the GDB remote stub, GDBserver
669 ** GDBserver is now supported on ARC GNU/Linux.
671 ** GDBserver is now supported on RISC-V GNU/Linux.
673 ** GDBserver no longer supports these host triplets:
684 i[34567]86-*-mingw32ce*
686 * Debugging MS-Windows processes now sets $_exitsignal when the
687 inferior is terminated by a signal, instead of setting $_exitcode.
689 * Multithreaded symbol loading has now been enabled by default on systems
690 that support it (see entry for GDB 9, below), providing faster
691 performance for programs with many symbols.
693 * The $_siginfo convenience variable now also works on Windows targets,
694 and will display the EXCEPTION_RECORD of the last handled exception.
696 * TUI windows can now be arranged horizontally.
698 * The command history filename can now be set to the empty string
699 either using 'set history filename' or by setting 'GDBHISTFILE=' in
700 the environment. The effect of setting this filename to the empty
701 string is that GDB will not try to load any previous command
704 * On Windows targets, it is now possible to debug 32-bit programs with a
709 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
710 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
711 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
712 running process, this new option indicates whether to detect
713 a mismatch between the current executable file loaded by GDB and the
714 executable file used to start the process. If 'ask', the default,
715 display a warning and ask the user whether to load the process
716 executable file; if 'warn', just display a warning; if 'off', don't
717 attempt to detect a mismatch.
719 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
720 Define a new TUI layout, specifying its name and the windows that
723 maintenance print xml-tdesc [FILE]
724 Prints the current target description as an XML document. If the
725 optional FILE is provided (which is an XML target description) then
726 the target description is read from FILE into GDB, and then
729 maintenance print core-file-backed-mappings
730 Prints file-backed mappings loaded from a core file's note section.
731 Output is expected to be similar to that of "info proc mappings".
733 set debug fortran-array-slicing on|off
734 show debug fortran-array-slicing
735 Print debugging when taking slices of Fortran arrays.
737 set fortran repack-array-slices on|off
738 show fortran repack-array-slices
739 When taking slices from Fortran arrays and strings, if the slice is
740 non-contiguous within the original value then, when this option is
741 on, the new value will be repacked into a single contiguous value.
742 When this option is off, then the value returned will consist of a
743 descriptor that describes the slice within the memory of the
744 original parent value.
748 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
749 The alias command can now specify default args for an alias.
750 GDB automatically prepends the alias default args to the argument list
751 provided explicitly by the user.
752 For example, to have a backtrace with full details, you can define
754 'alias bt_ALL = backtrace -entry-values both -frame-arg all
755 -past-main -past-entry -full'.
756 Alias default arguments can also use a set of nested 'with' commands,
757 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
758 defines the alias pp10 that will pretty print a maximum of 10 elements
759 of the given expression (if the expression is an array).
763 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
769 ** gdb.register_window_type can be used to implement new TUI windows
772 ** Dynamic types can now be queried. gdb.Type has a new attribute,
773 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
774 field of a dynamic type may have None for its "bitpos" attribute
777 ** Commands written in Python can be in the "TUI" help class by
778 registering with the new constant gdb.COMMAND_TUI.
780 ** New method gdb.PendingFrame.architecture () to retrieve the
781 architecture of the pending frame.
783 ** New gdb.Architecture.registers method that returns a
784 gdb.RegisterDescriptorIterator object, an iterator that returns
785 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
786 way to query the registers available for an architecture.
788 ** New gdb.Architecture.register_groups method that returns a
789 gdb.RegisterGroupIterator object, an iterator that returns
790 gdb.RegisterGroup objects. The new RegisterGroup is a way to
791 discover the available register groups.
795 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
797 ** Procedures 'memory-port-read-buffer-size',
798 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
799 and 'set-memory-port-write-buffer-size!' are deprecated. When
800 using Guile 2.2 and later, users who need to control the size of
801 a memory port's internal buffer can use the 'setvbuf' procedure.
805 * 'thread-exited' event is now available in the annotations interface.
807 * New built-in convenience variables $_gdb_major and $_gdb_minor
808 provide the GDB version. They are handy for conditionally using
809 features available only in or since specific GDB versions, in
810 scripts that should work error-free with many different versions,
811 such as in system-wide init files.
813 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
814 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
815 of the GDB settings and the GDB maintenance settings. They are handy
816 for changing the logic of user defined commands depending on the
817 current GDB settings.
819 * GDB now supports Thread Local Storage (TLS) variables on several
820 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
821 architectures require kernel changes. TLS is not yet supported for
822 amd64 and i386 process core dumps.
824 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
825 addresses that required unmasking are shown in the backtrace with the
828 * Two new convenience functions $_cimag and $_creal that extract the
829 imaginary and real parts respectively from complex numbers.
831 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
832 provide the exitcode or exit status of the shell commands launched by
833 GDB commands such as "shell", "pipe" and "make".
835 * The command define-prefix can now define user defined prefix commands.
836 User defined commands can now be defined using these user defined prefix
839 * Command names can now use the . character.
841 * The RX port now supports XML target descriptions.
843 * GDB now shows the Ada task names at more places, e.g. in task switching
846 * GDB can now be compiled with Python 3 on Windows.
848 * New convenience variable $_ada_exception holds the address of the
849 Ada exception being thrown. This is set by Ada-related catchpoints.
851 * GDB can now place breakpoints on nested functions and subroutines in
852 Fortran code. The '::' operator can be used between parent and
853 child scopes when placing breakpoints, for example:
855 (gdb) break outer_function::inner_function
857 The 'outer_function::' prefix is only needed if 'inner_function' is
858 not visible in the current scope.
860 * In addition to the system-wide gdbinit file, if configured with
861 --with-system-gdbinit-dir, GDB will now also load files in that directory
862 as system gdbinit files, unless the -nx or -n flag is provided. Files
863 with extensions .gdb, .py and .scm are supported as long as GDB was
864 compiled with support for that language.
866 * GDB now supports multithreaded symbol loading for higher performance.
867 This feature is still in testing, so it is disabled by default. You
868 can turn it on using 'maint set worker-threads unlimited'.
872 ** The gdb.Value type has a new method 'format_string' which returns a
873 string representing the value. The formatting is controlled by the
874 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
875 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
876 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
878 ** gdb.Type has a new property 'objfile' which returns the objfile the
881 ** The frame information printed by the python frame filtering code
882 is now consistent with what the 'backtrace' command prints when
883 there are no filters, or when the 'backtrace' '-no-filters' option
886 ** The new function gdb.lookup_static_symbol can be used to look up
887 symbols with static linkage.
889 ** The new function gdb.lookup_static_symbols can be used to look up
890 all static symbols with static linkage.
892 ** gdb.Objfile has new methods 'lookup_global_symbol' and
893 'lookup_static_symbol' to lookup a symbol from this objfile only.
895 ** gdb.Block now supports the dictionary syntax for accessing symbols in
896 this block (e.g. block['local_variable']).
900 | [COMMAND] | SHELL_COMMAND
901 | -d DELIM COMMAND DELIM SHELL_COMMAND
902 pipe [COMMAND] | SHELL_COMMAND
903 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
904 Executes COMMAND and sends its output to SHELL_COMMAND.
905 With no COMMAND, repeat the last executed command
906 and send its output to SHELL_COMMAND.
908 define-prefix COMMAND
909 Define or mark a command as a user-defined prefix command.
911 with SETTING [VALUE] [-- COMMAND]
912 w SETTING [VALUE] [-- COMMAND]
913 Temporarily set SETTING, run COMMAND, and restore SETTING.
914 Usage: with SETTING -- COMMAND
915 With no COMMAND, repeats the last executed command.
916 SETTING is any GDB setting you can change with the "set"
917 subcommands. For example, 'with language c -- print someobj'
918 temporarily switches to the C language in order to print someobj.
919 Settings can be combined: 'w lang c -- w print elements unlimited --
920 usercmd' switches to the C language and runs usercmd with no limit
921 of array elements to print.
923 maint with SETTING [VALUE] [-- COMMAND]
924 Like "with", but works with "maintenance set" settings.
926 set may-call-functions [on|off]
927 show may-call-functions
928 This controls whether GDB will attempt to call functions in
929 the program, such as with expressions in the print command. It
930 defaults to on. Calling functions in the program being debugged
931 can have undesired side effects. It is now possible to forbid
932 such function calls. If function calls are forbidden, GDB will throw
933 an error when a command (such as print expression) calls a function
936 set print finish [on|off]
938 This controls whether the `finish' command will display the value
939 that is returned by the current function. When `off', the value is
940 still entered into the value history, but it is not printed. The
945 Allows deeply nested structures to be simplified when printing by
946 replacing deeply nested parts (beyond the max-depth) with ellipses.
947 The default max-depth is 20, but this can be set to unlimited to get
948 the old behavior back.
950 set print raw-values [on|off]
951 show print raw-values
952 By default, GDB applies the enabled pretty printers when printing a
953 value. This allows to ignore the enabled pretty printers for a series
954 of commands. The default is 'off'.
956 set logging debugredirect [on|off]
957 By default, GDB debug output will go to both the terminal and the logfile.
958 Set if you want debug output to go only to the log file.
960 set style title foreground COLOR
961 set style title background COLOR
962 set style title intensity VALUE
963 Control the styling of titles.
965 set style highlight foreground COLOR
966 set style highlight background COLOR
967 set style highlight intensity VALUE
968 Control the styling of highlightings.
970 maint set worker-threads
971 maint show worker-threads
972 Control the number of worker threads that can be used by GDB. The
973 default is 0. "unlimited" lets GDB choose a number that is
974 reasonable. Currently worker threads are only used when demangling
975 the names of linker symbols.
977 set style tui-border foreground COLOR
978 set style tui-border background COLOR
979 Control the styling of TUI borders.
981 set style tui-active-border foreground COLOR
982 set style tui-active-border background COLOR
983 Control the styling of the active TUI border.
985 maint set test-settings KIND
986 maint show test-settings KIND
987 A set of commands used by the testsuite for exercising the settings
990 maint set tui-resize-message [on|off]
991 maint show tui-resize-message
992 Control whether GDB prints a message each time the terminal is
993 resized when in TUI mode. This is primarily useful for testing the
996 set print frame-info [short-location|location|location-and-address
997 |source-and-location|source-line|auto]
998 show print frame-info
999 This controls what frame information is printed by the commands printing
1000 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1001 'frame', 'stepi'. The python frame filtering also respect this setting.
1002 The 'backtrace' '-frame-info' option can override this global setting.
1004 set tui compact-source
1005 show tui compact-source
1007 Enable the "compact" display mode for the TUI source window. The
1008 compact display uses only as much space as is needed for the line
1009 numbers in the current file, and only a single space to separate the
1010 line numbers from the source.
1012 info modules [-q] [REGEXP]
1013 Return a list of Fortran modules matching REGEXP, or all modules if
1016 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1017 Return a list of functions within all modules, grouped by module.
1018 The list of functions can be restricted with the optional regular
1019 expressions. MODULE_REGEXP matches against the module name,
1020 TYPE_REGEXP matches against the function type signature, and REGEXP
1021 matches against the function name.
1023 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1024 Return a list of variables within all modules, grouped by module.
1025 The list of variables can be restricted with the optional regular
1026 expressions. MODULE_REGEXP matches against the module name,
1027 TYPE_REGEXP matches against the variable type, and REGEXP matches
1028 against the variable name.
1030 set debug remote-packet-max-chars
1031 show debug remote-packet-max-chars
1032 Controls the number of characters to output in a remote packet when using
1034 The default is 512 bytes.
1037 Lists the target connections currently in use.
1042 The "help" command uses the title style to enhance the
1043 readibility of its output by styling the classes and
1047 Similarly to "help", the "apropos" command also uses the
1048 title style for the command names. "apropos" accepts now
1049 a flag "-v" (verbose) to show the full documentation
1050 of matching commands and to use the highlight style to mark
1051 the documentation parts matching REGEXP.
1055 The GDB printf and eval commands can now print C-style and Ada-style
1056 string convenience variables without calling functions in the program.
1057 This allows to do formatted printing of strings without having
1058 a running inferior, or when debugging a core dump.
1060 info sources [-dirname | -basename] [--] [REGEXP]
1061 This command has now optional arguments to only print the files
1062 whose names match REGEXP. The arguments -dirname and -basename
1063 allow to restrict matching respectively to the dirname and basename
1067 The "show style" and its subcommands are now styling
1068 a style name in their output using its own style, to help
1069 the user visualize the different styles.
1071 set print frame-arguments
1072 The new value 'presence' indicates to only indicate the presence of
1073 arguments using ..., instead of printing argument names and values.
1075 set print raw-frame-arguments
1076 show print raw-frame-arguments
1078 These commands replace the similarly-named "set/show print raw
1079 frame-arguments" commands (now with a dash instead of a space). The
1080 old commands are now deprecated and may be removed in a future
1083 add-inferior [-no-connection]
1084 The add-inferior command now supports a "-no-connection" flag that
1085 makes the new inferior start with no target connection associated.
1086 By default, the new inferior inherits the target connection of the
1087 current inferior. See also "info connections".
1090 This command's output now includes a new "Connection" column
1091 indicating which target connection an inferior is bound to. See
1092 "info connections" above.
1094 maint test-options require-delimiter
1095 maint test-options unknown-is-error
1096 maint test-options unknown-is-operand
1097 maint show test-options-completion-result
1098 Commands used by the testsuite to validate the command options
1101 focus, winheight, +, -, >, <
1102 These commands are now case-sensitive.
1104 * New command options, command completion
1106 GDB now has a standard infrastructure to support dash-style command
1107 options ('-OPT'). One benefit is that commands that use it can
1108 easily support completion of command line arguments. Try "CMD
1109 -[TAB]" or "help CMD" to find options supported by a command. Over
1110 time, we intend to migrate most commands to this infrastructure. A
1111 number of commands got support for new command options in this
1114 ** The "print" and "compile print" commands now support a number of
1115 options that allow overriding relevant global print settings as
1116 set by "set print" subcommands:
1120 -array-indexes [on|off]
1121 -elements NUMBER|unlimited
1125 -raw-values [on|off]
1126 -repeats NUMBER|unlimited
1127 -static-members [on|off]
1132 Note that because the "print"/"compile print" commands accept
1133 arbitrary expressions which may look like options (including
1134 abbreviations), if you specify any command option, then you must
1135 use a double dash ("--") to mark the end of argument processing.
1137 ** The "backtrace" command now supports a number of options that
1138 allow overriding relevant global print settings as set by "set
1139 backtrace" and "set print" subcommands:
1141 -entry-values no|only|preferred|if-needed|both|compact|default
1142 -frame-arguments all|scalars|none
1143 -raw-frame-arguments [on|off]
1144 -frame-info auto|source-line|location|source-and-location
1145 |location-and-address|short-location
1147 -past-entry [on|off]
1149 In addition, the full/no-filters/hide qualifiers are now also
1150 exposed as command options too:
1156 ** The "frame apply", "tfaas" and "faas" commands similarly now
1157 support the following options:
1160 -past-entry [on|off]
1162 ** The new "info sources" options -dirname and -basename options
1163 are using the standard '-OPT' infrastructure.
1165 All options above can also be abbreviated. The argument of boolean
1166 (on/off) options can be 0/1 too, and also the argument is assumed
1167 "on" if omitted. This allows writing compact command invocations,
1170 (gdb) p -ra -p -o 0 -- *myptr
1172 The above is equivalent to:
1174 (gdb) print -raw-values -pretty -object off -- *myptr
1176 ** The "info types" command now supports the '-q' flag to disable
1177 printing of some header information in a similar fashion to "info
1178 variables" and "info functions".
1180 ** The "info variables", "info functions", and "whereis" commands
1181 now take a '-n' flag that excludes non-debug symbols (symbols
1182 from the symbol table, not from the debug info such as DWARF)
1185 * Completion improvements
1187 ** GDB can now complete the options of the "thread apply all" and
1188 "taas" commands, and their "-ascending" option can now be
1191 ** GDB can now complete the options of the "info threads", "info
1192 functions", "info variables", "info locals", and "info args"
1195 ** GDB can now complete the options of the "compile file" and
1196 "compile code" commands. The "compile file" command now
1197 completes on filenames.
1199 ** GDB can now complete the backtrace command's
1200 "full/no-filters/hide" qualifiers.
1202 * In settings, you can now abbreviate "unlimited".
1204 E.g., "set print elements u" is now equivalent to "set print
1205 elements unlimited".
1210 This lists all the possible completions for the rest of the line, if it
1211 were to be given as a command itself. This is intended for use by MI
1212 frontends in cases when separate CLI and MI channels cannot be used.
1214 -catch-throw, -catch-rethrow, and -catch-catch
1215 These can be used to catch C++ exceptions in a similar fashion to
1216 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1218 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1219 These commands are the MI equivalent of the CLI commands 'info
1220 functions', 'info types', and 'info variables' respectively.
1222 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1225 -symbol-info-module-functions and -symbol-info-module-variables.
1226 These commands are the MI equivalent of the CLI commands 'info
1227 module functions' and 'info module variables'.
1231 ** The default version of the MI interpreter is now 3 (-i=mi3).
1233 ** The output of information about multi-location breakpoints (which is
1234 syntactically incorrect in MI 2) has changed in MI 3. This affects
1235 the following commands and events:
1239 - =breakpoint-created
1240 - =breakpoint-modified
1242 The -fix-multi-location-breakpoint-output command can be used to enable
1243 this behavior with previous MI versions.
1245 ** Backtraces and frames include a new optional field addr_flags which is
1246 given after the addr field. On AArch64 this contains PAC if the address
1247 has been masked in the frame. On all other targets the field is not
1252 The testsuite now creates the files gdb.cmd (containing the arguments
1253 used to launch GDB) and gdb.in (containing all the commands sent to
1254 GDB) in the output directory for each test script. Multiple invocations
1255 are appended with .1, .2, .3 etc.
1257 * Building GDB and GDBserver now requires GNU make >= 3.82.
1259 Using another implementation of the make program or an earlier version of
1260 GNU make to build GDB or GDBserver is not supported.
1262 * Building GDB now requires GNU readline >= 7.0.
1264 GDB now bundles GNU readline 8.0, but if you choose to use
1265 --with-system-readline, only readline >= 7.0 can be used.
1267 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1268 from .inputrc to bind keys in this keymap. This feature is only
1269 available when gdb is built against GNU readline 8.0 or later.
1271 * Removed targets and native configurations
1273 GDB no longer supports debugging the Cell Broadband Engine. This includes
1274 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1275 of Cell/B.E. applications that use both the PPU and SPU architectures.
1281 * Removed targets and native configurations
1283 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1284 sparc*-*-solaris2.10
1286 *** Changes in GDB 8.3
1288 * GDB and GDBserver now support access to additional registers on
1289 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1292 * GDB now has experimental support for the compilation and injection of
1293 C++ source code into the inferior. This beta release does not include
1294 support for several language features, such as templates, constructors,
1297 This feature requires GCC 7.1 or higher built with libcp1.so
1300 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1301 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1302 'ADDRESS:PORT' method.
1304 * DWARF index cache: GDB can now automatically save indices of DWARF
1305 symbols on disk to speed up further loading of the same binaries.
1307 * Ada task switching is now supported on aarch64-elf targets when
1308 debugging a program using the Ravenscar Profile. For more information,
1309 see the "Tasking Support when using the Ravenscar Profile" section
1310 in the GDB user manual.
1312 * GDB in batch mode now exits with status 1 if the last command to be
1315 * The RISC-V target now supports target descriptions.
1317 * System call catchpoints now support system call aliases on FreeBSD.
1318 When the ABI of a system call changes in FreeBSD, this is
1319 implemented by leaving a compatibility system call using the old ABI
1320 at the existing number and allocating a new system call number for
1321 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1322 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1323 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1324 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1325 so that a system call catchpoint for the 'kevent' system call will
1326 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1327 binaries. This ensures that 'kevent' system calls are caught for
1328 binaries using either the old or new ABIs.
1330 * Terminal styling is now available for the CLI and the TUI. GNU
1331 Source Highlight can additionally be used to provide styling of
1332 source code snippets. See the "set style" commands, below, for more
1335 * Removed support for old demangling styles arm, edg, gnu, hp and
1340 set debug compile-cplus-types
1341 show debug compile-cplus-types
1342 Control the display of debug output about type conversion in the
1343 C++ compile feature. Commands have no effect while compiling
1344 for other languages.
1348 Control whether debug output about files/functions skipping is
1351 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1352 Apply a command to some frames.
1353 FLAG arguments allow to control what output to produce and how to handle
1354 errors raised when applying COMMAND to a frame.
1357 Apply a command to all threads (ignoring errors and empty output).
1358 Shortcut for 'thread apply all -s COMMAND'.
1361 Apply a command to all frames (ignoring errors and empty output).
1362 Shortcut for 'frame apply all -s COMMAND'.
1365 Apply a command to all frames of all threads (ignoring errors and empty
1367 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1369 maint set dwarf unwinders (on|off)
1370 maint show dwarf unwinders
1371 Control whether DWARF unwinders can be used.
1374 Display a list of open files for a process.
1378 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1379 These commands all now take a frame specification which
1380 is either a frame level, or one of the keywords 'level', 'address',
1381 'function', or 'view' followed by a parameter. Selecting a frame by
1382 address, or viewing a frame outside the current backtrace now
1383 requires the use of a keyword. Selecting a frame by level is
1384 unchanged. The MI comment "-stack-select-frame" is unchanged.
1386 target remote FILENAME
1387 target extended-remote FILENAME
1388 If FILENAME is a Unix domain socket, GDB will attempt to connect
1389 to this socket instead of opening FILENAME as a character device.
1391 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1392 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1393 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1394 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1395 These commands can now print only the searched entities
1396 matching the provided regexp(s), giving a condition
1397 on the entity names or entity types. The flag -q disables
1398 printing headers or informations messages.
1404 These commands now determine the syntax for the shown entities
1405 according to the language chosen by `set language'. In particular,
1406 `set language auto' means to automatically choose the language of
1409 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1410 The 'thread apply' command accepts new FLAG arguments.
1411 FLAG arguments allow to control what output to produce and how to handle
1412 errors raised when applying COMMAND to a thread.
1414 set tui tab-width NCHARS
1415 show tui tab-width NCHARS
1416 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1418 set style enabled [on|off]
1420 Enable or disable terminal styling. Styling is enabled by default
1421 on most hosts, but disabled by default when in batch mode.
1423 set style sources [on|off]
1425 Enable or disable source code styling. Source code styling is
1426 enabled by default, but only takes effect if styling in general is
1427 enabled, and if GDB was linked with GNU Source Highlight.
1429 set style filename foreground COLOR
1430 set style filename background COLOR
1431 set style filename intensity VALUE
1432 Control the styling of file names.
1434 set style function foreground COLOR
1435 set style function background COLOR
1436 set style function intensity VALUE
1437 Control the styling of function names.
1439 set style variable foreground COLOR
1440 set style variable background COLOR
1441 set style variable intensity VALUE
1442 Control the styling of variable names.
1444 set style address foreground COLOR
1445 set style address background COLOR
1446 set style address intensity VALUE
1447 Control the styling of addresses.
1451 ** The '-data-disassemble' MI command now accepts an '-a' option to
1452 disassemble the whole function surrounding the given program
1453 counter value or function name. Support for this feature can be
1454 verified by using the "-list-features" command, which should
1455 contain "data-disassemble-a-option".
1457 ** Command responses and notifications that include a frame now include
1458 the frame's architecture in a new "arch" attribute.
1460 * New native configurations
1462 GNU/Linux/RISC-V riscv*-*-linux*
1463 FreeBSD/riscv riscv*-*-freebsd*
1467 GNU/Linux/RISC-V riscv*-*-linux*
1468 CSKY ELF csky*-*-elf
1469 CSKY GNU/LINUX csky*-*-linux
1470 FreeBSD/riscv riscv*-*-freebsd*
1472 GNU/Linux/OpenRISC or1k*-*-linux*
1476 GDB no longer supports native debugging on versions of MS-Windows
1481 ** GDB no longer supports Python versions less than 2.6.
1483 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1484 space associated to that inferior.
1486 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1487 of objfiles associated to that program space.
1489 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1490 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1493 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1494 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1495 correct and did not work properly.
1497 ** The gdb.Value type has a new constructor, which is used to construct a
1498 gdb.Value from a Python buffer object and a gdb.Type.
1504 Enable or disable the undefined behavior sanitizer. This is
1505 disabled by default, but passing --enable-ubsan=yes or
1506 --enable-ubsan=auto to configure will enable it. Enabling this can
1507 cause a performance penalty. The undefined behavior sanitizer was
1508 first introduced in GCC 4.9.
1510 *** Changes in GDB 8.2
1512 * The 'set disassembler-options' command now supports specifying options
1513 for the MIPS target.
1515 * The 'symbol-file' command now accepts an '-o' option to add a relative
1516 offset to all sections.
1518 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1519 a relative offset to all sections, but it allows to override the load
1520 address of individual sections using '-s'.
1522 * The 'add-symbol-file' command no longer requires the second argument
1523 (address of the text section).
1525 * The endianness used with the 'set endian auto' mode in the absence of
1526 an executable selected for debugging is now the last endianness chosen
1527 either by one of the 'set endian big' and 'set endian little' commands
1528 or by inferring from the last executable used, rather than the startup
1531 * The pager now allows a "c" response, meaning to disable the pager
1532 for the rest of the current command.
1534 * The commands 'info variables/functions/types' now show the source line
1535 numbers of symbol definitions when available.
1537 * 'info proc' now works on running processes on FreeBSD systems and core
1538 files created on FreeBSD systems.
1540 * C expressions can now use _Alignof, and C++ expressions can now use
1543 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1544 the vector length while the process is running.
1550 Control display of debugging info regarding the FreeBSD native target.
1552 set|show varsize-limit
1553 This new setting allows the user to control the maximum size of Ada
1554 objects being printed when those objects have a variable type,
1555 instead of that maximum size being hardcoded to 65536 bytes.
1557 set|show record btrace cpu
1558 Controls the processor to be used for enabling errata workarounds for
1559 branch trace decode.
1561 maint check libthread-db
1562 Run integrity checks on the current inferior's thread debugging
1565 maint set check-libthread-db (on|off)
1566 maint show check-libthread-db
1567 Control whether to run integrity checks on inferior specific thread
1568 debugging libraries as they are loaded. The default is not to
1569 perform such checks.
1573 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1575 ** The commands attached to a breakpoint can be set by assigning to
1576 the breakpoint's "commands" field.
1578 ** gdb.execute can now execute multi-line gdb commands.
1580 ** The new functions gdb.convenience_variable and
1581 gdb.set_convenience_variable can be used to get and set the value
1582 of convenience variables.
1584 ** A gdb.Parameter will no longer print the "set" help text on an
1585 ordinary "set"; instead by default a "set" will be silent unless
1586 the get_set_string method returns a non-empty string.
1590 RiscV ELF riscv*-*-elf
1592 * Removed targets and native configurations
1594 m88k running OpenBSD m88*-*-openbsd*
1595 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1596 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1597 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1599 * Aarch64/Linux hardware watchpoints improvements
1601 Hardware watchpoints on unaligned addresses are now properly
1602 supported when running Linux kernel 4.10 or higher: read and access
1603 watchpoints are no longer spuriously missed, and all watchpoints
1604 lengths between 1 and 8 bytes are supported. On older kernels,
1605 watchpoints set on unaligned addresses are no longer missed, with
1606 the tradeoff that there is a possibility of false hits being
1611 --enable-codesign=CERT
1612 This can be used to invoke "codesign -s CERT" after building gdb.
1613 This option is useful on macOS, where code signing is required for
1614 gdb to work properly.
1616 --disable-gdbcli has been removed
1617 This is now silently accepted, but does nothing.
1619 *** Changes in GDB 8.1
1621 * GDB now supports dynamically creating arbitrary register groups specified
1622 in XML target descriptions. This allows for finer grain grouping of
1623 registers on systems with a large amount of registers.
1625 * The 'ptype' command now accepts a '/o' flag, which prints the
1626 offsets and sizes of fields in a struct, like the pahole(1) tool.
1628 * New "--readnever" command line option instructs GDB to not read each
1629 symbol file's symbolic debug information. This makes startup faster
1630 but at the expense of not being able to perform symbolic debugging.
1631 This option is intended for use cases where symbolic debugging will
1632 not be used, e.g., when you only need to dump the debuggee's core.
1634 * GDB now uses the GNU MPFR library, if available, to emulate target
1635 floating-point arithmetic during expression evaluation when the target
1636 uses different floating-point formats than the host. At least version
1637 3.1 of GNU MPFR is required.
1639 * GDB now supports access to the guarded-storage-control registers and the
1640 software-based guarded-storage broadcast control registers on IBM z14.
1642 * On Unix systems, GDB now supports transmitting environment variables
1643 that are to be set or unset to GDBserver. These variables will
1644 affect the environment to be passed to the remote inferior.
1646 To inform GDB of environment variables that are to be transmitted to
1647 GDBserver, use the "set environment" command. Only user set
1648 environment variables are sent to GDBserver.
1650 To inform GDB of environment variables that are to be unset before
1651 the remote inferior is started by the GDBserver, use the "unset
1652 environment" command.
1654 * Completion improvements
1656 ** GDB can now complete function parameters in linespecs and
1657 explicit locations without quoting. When setting breakpoints,
1658 quoting around functions names to help with TAB-completion is
1659 generally no longer necessary. For example, this now completes
1662 (gdb) b function(in[TAB]
1663 (gdb) b function(int)
1665 Related, GDB is no longer confused with completing functions in
1666 C++ anonymous namespaces:
1669 (gdb) b (anonymous namespace)::[TAB][TAB]
1670 (anonymous namespace)::a_function()
1671 (anonymous namespace)::b_function()
1673 ** GDB now has much improved linespec and explicit locations TAB
1674 completion support, that better understands what you're
1675 completing and offers better suggestions. For example, GDB no
1676 longer offers data symbols as possible completions when you're
1677 setting a breakpoint.
1679 ** GDB now TAB-completes label symbol names.
1681 ** The "complete" command now mimics TAB completion accurately.
1683 * New command line options (gcore)
1686 Dump all memory mappings.
1688 * Breakpoints on C++ functions are now set on all scopes by default
1690 By default, breakpoints on functions/methods are now interpreted as
1691 specifying all functions with the given name ignoring missing
1692 leading scopes (namespaces and classes).
1694 For example, assuming a C++ program with symbols named:
1699 both commands "break func()" and "break B::func()" set a breakpoint
1702 You can use the new flag "-qualified" to override this. This makes
1703 GDB interpret the specified function name as a complete
1704 fully-qualified name instead. For example, using the same C++
1705 program, the "break -q B::func" command sets a breakpoint on
1706 "B::func", only. A parameter has been added to the Python
1707 gdb.Breakpoint constructor to achieve the same result when creating
1708 a breakpoint from Python.
1710 * Breakpoints on functions marked with C++ ABI tags
1712 GDB can now set breakpoints on functions marked with C++ ABI tags
1713 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1714 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1716 Functions with a C++11 abi tag are demangled/displayed like this:
1718 function[abi:cxx11](int)
1721 You can now set a breakpoint on such functions simply as if they had
1724 (gdb) b function(int)
1726 Or if you need to disambiguate between tags, like:
1728 (gdb) b function[abi:other_tag](int)
1730 Tab completion was adjusted accordingly as well.
1734 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1735 gdb.new_thread are emitted. See the manual for further
1736 description of these.
1738 ** A new function, "gdb.rbreak" has been added to the Python API.
1739 This function allows the setting of a large number of breakpoints
1740 via a regex pattern in Python. See the manual for further details.
1742 ** Python breakpoints can now accept explicit locations. See the
1743 manual for a further description of this feature.
1746 * New features in the GDB remote stub, GDBserver
1748 ** GDBserver is now able to start inferior processes with a
1749 specified initial working directory.
1751 The user can set the desired working directory to be used from
1752 GDB using the new "set cwd" command.
1754 ** New "--selftest" command line option runs some GDBserver self
1755 tests. These self tests are disabled in releases.
1757 ** On Unix systems, GDBserver now does globbing expansion and variable
1758 substitution in inferior command line arguments.
1760 This is done by starting inferiors using a shell, like GDB does.
1761 See "set startup-with-shell" in the user manual for how to disable
1762 this from GDB when using "target extended-remote". When using
1763 "target remote", you can disable the startup with shell by using the
1764 new "--no-startup-with-shell" GDBserver command line option.
1766 ** On Unix systems, GDBserver now supports receiving environment
1767 variables that are to be set or unset from GDB. These variables
1768 will affect the environment to be passed to the inferior.
1770 * When catching an Ada exception raised with a message, GDB now prints
1771 the message in the catchpoint hit notification. In GDB/MI mode, that
1772 information is provided as an extra field named "exception-message"
1773 in the *stopped notification.
1775 * Trait objects can now be inspected When debugging Rust code. This
1776 requires compiler support which will appear in Rust 1.24.
1778 * New remote packets
1780 QEnvironmentHexEncoded
1781 Inform GDBserver of an environment variable that is to be passed to
1782 the inferior when starting it.
1785 Inform GDBserver of an environment variable that is to be unset
1786 before starting the remote inferior.
1789 Inform GDBserver that the environment should be reset (i.e.,
1790 user-set environment variables should be unset).
1793 Indicates whether the inferior must be started with a shell or not.
1796 Tell GDBserver that the inferior to be started should use a specific
1799 * The "maintenance print c-tdesc" command now takes an optional
1800 argument which is the file name of XML target description.
1802 * The "maintenance selftest" command now takes an optional argument to
1803 filter the tests to be run.
1805 * The "enable", and "disable" commands now accept a range of
1806 breakpoint locations, e.g. "enable 1.3-5".
1811 Set and show the current working directory for the inferior.
1813 set|show compile-gcc
1814 Set and show compilation command used for compiling and injecting code
1815 with the 'compile' commands.
1817 set debug separate-debug-file
1818 show debug separate-debug-file
1819 Control the display of debug output about separate debug file search.
1821 set dump-excluded-mappings
1822 show dump-excluded-mappings
1823 Control whether mappings marked with the VM_DONTDUMP flag should be
1824 dumped when generating a core file.
1826 maint info selftests
1827 List the registered selftests.
1830 Start the debugged program stopping at the first instruction.
1833 Control display of debugging messages related to OpenRISC targets.
1835 set|show print type nested-type-limit
1836 Set and show the limit of nesting level for nested types that the
1837 type printer will show.
1839 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
1842 * Safer/improved support for debugging with no debug info
1844 GDB no longer assumes functions with no debug information return
1847 This means that GDB now refuses to call such functions unless you
1848 tell it the function's type, by either casting the call to the
1849 declared return type, or by casting the function to a function
1850 pointer of the right type, and calling that:
1852 (gdb) p getenv ("PATH")
1853 'getenv' has unknown return type; cast the call to its declared return type
1854 (gdb) p (char *) getenv ("PATH")
1855 $1 = 0x7fffffffe "/usr/local/bin:/"...
1856 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
1857 $2 = 0x7fffffffe "/usr/local/bin:/"...
1859 Similarly, GDB no longer assumes that global variables with no debug
1860 info have type 'int', and refuses to print the variable's value
1861 unless you tell it the variable's type:
1864 'var' has unknown type; cast it to its declared type
1868 * New native configurations
1870 FreeBSD/aarch64 aarch64*-*-freebsd*
1871 FreeBSD/arm arm*-*-freebsd*
1875 FreeBSD/aarch64 aarch64*-*-freebsd*
1876 FreeBSD/arm arm*-*-freebsd*
1877 OpenRISC ELF or1k*-*-elf
1879 * Removed targets and native configurations
1881 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
1883 *** Changes in GDB 8.0
1885 * GDB now supports access to the PKU register on GNU/Linux. The register is
1886 added by the Memory Protection Keys for Userspace feature which will be
1887 available in future Intel CPUs.
1889 * GDB now supports C++11 rvalue references.
1893 ** New functions to start, stop and access a running btrace recording.
1894 ** Rvalue references are now supported in gdb.Type.
1896 * GDB now supports recording and replaying rdrand and rdseed Intel 64
1899 * Building GDB and GDBserver now requires a C++11 compiler.
1901 For example, GCC 4.8 or later.
1903 It is no longer possible to build GDB or GDBserver with a C
1904 compiler. The --disable-build-with-cxx configure option has been
1907 * Building GDB and GDBserver now requires GNU make >= 3.81.
1909 It is no longer supported to build GDB or GDBserver with another
1910 implementation of the make program or an earlier version of GNU make.
1912 * Native debugging on MS-Windows supports command-line redirection
1914 Command-line arguments used for starting programs on MS-Windows can
1915 now include redirection symbols supported by native Windows shells,
1916 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
1917 as "run", "start", and "set args", as well as the corresponding MI
1920 * Support for thread names on MS-Windows.
1922 GDB now catches and handles the special exception that programs
1923 running on MS-Windows use to assign names to threads in the
1926 * Support for Java programs compiled with gcj has been removed.
1928 * User commands now accept an unlimited number of arguments.
1929 Previously, only up to 10 was accepted.
1931 * The "eval" command now expands user-defined command arguments.
1933 This makes it easier to process a variable number of arguments:
1938 eval "print $arg%d", $i
1943 * Target descriptions can now describe registers for sparc32 and sparc64.
1945 * GDB now supports DWARF version 5 (debug information format).
1946 Its .debug_names index is not yet supported.
1948 * New native configurations
1950 FreeBSD/mips mips*-*-freebsd
1954 Synopsys ARC arc*-*-elf32
1955 FreeBSD/mips mips*-*-freebsd
1957 * Removed targets and native configurations
1959 Alpha running FreeBSD alpha*-*-freebsd*
1960 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
1965 Erases all the flash memory regions reported by the target.
1967 maint print arc arc-instruction address
1968 Print internal disassembler information about instruction at a given address.
1972 set disassembler-options
1973 show disassembler-options
1974 Controls the passing of target specific information to the disassembler.
1975 If it is necessary to specify more than one disassembler option then
1976 multiple options can be placed together into a comma separated list.
1977 The default value is the empty string. Currently, the only supported
1978 targets are ARM, PowerPC and S/390.
1983 Erases all the flash memory regions reported by the target. This is
1984 equivalent to the CLI command flash-erase.
1986 -file-list-shared-libraries
1987 List the shared libraries in the program. This is
1988 equivalent to the CLI command "info shared".
1991 Catchpoints stopping the program when Ada exceptions are
1992 handled. This is equivalent to the CLI command "catch handlers".
1994 *** Changes in GDB 7.12
1996 * GDB and GDBserver now build with a C++ compiler by default.
1998 The --enable-build-with-cxx configure option is now enabled by
1999 default. One must now explicitly configure with
2000 --disable-build-with-cxx in order to build with a C compiler. This
2001 option will be removed in a future release.
2003 * GDBserver now supports recording btrace without maintaining an active
2006 * GDB now supports a negative repeat count in the 'x' command to examine
2007 memory backward from the given address. For example:
2010 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2011 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2012 (gdb) x/-5i 0x0000000000400580
2013 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2014 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2015 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2016 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2017 0x40057b <main(int, char**)+25>:
2018 callq 0x400536 <Func1(int, char const*)>
2020 * Fortran: Support structures with fields of dynamic types and
2021 arrays of dynamic types.
2023 * The symbol dumping maintenance commands have new syntax.
2024 maint print symbols [-pc address] [--] [filename]
2025 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2026 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2027 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2028 maint print msymbols [-objfile objfile] [--] [filename]
2030 * GDB now supports multibit bitfields and enums in target register
2033 * New Python-based convenience function $_as_string(val), which returns
2034 the textual representation of a value. This function is especially
2035 useful to obtain the text label of an enum value.
2037 * Intel MPX bound violation handling.
2039 Segmentation faults caused by a Intel MPX boundary violation
2040 now display the kind of violation (upper or lower), the memory
2041 address accessed and the memory bounds, along with the usual
2042 signal received and code location.
2046 Program received signal SIGSEGV, Segmentation fault
2047 Upper bound violation while accessing address 0x7fffffffc3b3
2048 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2049 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2051 * Rust language support.
2052 GDB now supports debugging programs written in the Rust programming
2053 language. See https://www.rust-lang.org/ for more information about
2056 * Support for running interpreters on specified input/output devices
2058 GDB now supports a new mechanism that allows frontends to provide
2059 fully featured GDB console views, as a better alternative to
2060 building such views on top of the "-interpreter-exec console"
2061 command. See the new "new-ui" command below. With that command,
2062 frontends can now start GDB in the traditional command-line mode
2063 running in an embedded terminal emulator widget, and create a
2064 separate MI interpreter running on a specified i/o device. In this
2065 way, GDB handles line editing, history, tab completion, etc. in the
2066 console all by itself, and the GUI uses the separate MI interpreter
2067 for its own control and synchronization, invisible to the command
2070 * The "catch syscall" command catches groups of related syscalls.
2072 The "catch syscall" command now supports catching a group of related
2073 syscalls using the 'group:' or 'g:' prefix.
2078 skip -gfile file-glob-pattern
2079 skip -function function
2080 skip -rfunction regular-expression
2081 A generalized form of the skip command, with new support for
2082 glob-style file names and regular expressions for function names.
2083 Additionally, a file spec and a function spec may now be combined.
2085 maint info line-table REGEXP
2086 Display the contents of GDB's internal line table data structure.
2089 Run any GDB unit tests that were compiled in.
2092 Start a new user interface instance running INTERP as interpreter,
2093 using the TTY file for input/output.
2097 ** gdb.Breakpoint objects have a new attribute "pending", which
2098 indicates whether the breakpoint is pending.
2099 ** Three new breakpoint-related events have been added:
2100 gdb.breakpoint_created, gdb.breakpoint_modified, and
2101 gdb.breakpoint_deleted.
2103 signal-event EVENTID
2104 Signal ("set") the given MS-Windows event object. This is used in
2105 conjunction with the Windows JIT debugging (AeDebug) support, where
2106 the OS suspends a crashing process until a debugger can attach to
2107 it. Resuming the crashing process, in order to debug it, is done by
2108 signalling an event.
2110 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2111 was added in GDBserver, including JIT compiling fast tracepoint's
2112 conditional expression bytecode into native code.
2114 * Support for various remote target protocols and ROM monitors has
2117 target m32rsdi Remote M32R debugging over SDI
2118 target mips MIPS remote debugging protocol
2119 target pmon PMON ROM monitor
2120 target ddb NEC's DDB variant of PMON for Vr4300
2121 target rockhopper NEC RockHopper variant of PMON
2122 target lsi LSI variant of PMO
2124 * Support for tracepoints and fast tracepoints on powerpc-linux,
2125 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2126 including JIT compiling fast tracepoint's conditional expression
2127 bytecode into native code.
2129 * MI async record =record-started now includes the method and format used for
2130 recording. For example:
2132 =record-started,thread-group="i1",method="btrace",format="bts"
2134 * MI async record =thread-selected now includes the frame field. For example:
2136 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2140 Andes NDS32 nds32*-*-elf
2142 *** Changes in GDB 7.11
2144 * GDB now supports debugging kernel-based threads on FreeBSD.
2146 * Per-inferior thread numbers
2148 Thread numbers are now per inferior instead of global. If you're
2149 debugging multiple inferiors, GDB displays thread IDs using a
2150 qualified INF_NUM.THR_NUM form. For example:
2154 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2155 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2156 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2157 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2159 As consequence, thread numbers as visible in the $_thread
2160 convenience variable and in Python's InferiorThread.num attribute
2161 are no longer unique between inferiors.
2163 GDB now maintains a second thread ID per thread, referred to as the
2164 global thread ID, which is the new equivalent of thread numbers in
2165 previous releases. See also $_gthread below.
2167 For backwards compatibility, MI's thread IDs always refer to global
2170 * Commands that accept thread IDs now accept the qualified
2171 INF_NUM.THR_NUM form as well. For example:
2174 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2177 * In commands that accept a list of thread IDs, you can now refer to
2178 all threads of an inferior using a star wildcard. GDB accepts
2179 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2180 refer to all threads of the current inferior. For example, "info
2183 * You can use "info threads -gid" to display the global thread ID of
2186 * The new convenience variable $_gthread holds the global number of
2189 * The new convenience variable $_inferior holds the number of the
2192 * GDB now displays the ID and name of the thread that hit a breakpoint
2193 or received a signal, if your program is multi-threaded. For
2196 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2197 Thread 1 "main" received signal SIGINT, Interrupt.
2199 * Record btrace now supports non-stop mode.
2201 * Support for tracepoints on aarch64-linux was added in GDBserver.
2203 * The 'record instruction-history' command now indicates speculative execution
2204 when using the Intel Processor Trace recording format.
2206 * GDB now allows users to specify explicit locations, bypassing
2207 the linespec parser. This feature is also available to GDB/MI
2210 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2211 GDB now is able to debug both AArch64 applications and ARM applications
2214 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2215 including JIT compiling fast tracepoint's conditional expression bytecode
2218 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2220 * "info threads", "info inferiors", "info display", "info checkpoints"
2221 and "maint info program-spaces" now list the corresponding items in
2222 ascending ID order, for consistency with all other "info" commands.
2224 * In Ada, the overloads selection menu has been enhanced to display the
2225 parameter types and the return types for the matching overloaded subprograms.
2229 maint set target-non-stop (on|off|auto)
2230 maint show target-non-stop
2231 Control whether GDB targets always operate in non-stop mode even if
2232 "set non-stop" is "off". The default is "auto", meaning non-stop
2233 mode is enabled if supported by the target.
2235 maint set bfd-sharing
2236 maint show bfd-sharing
2237 Control the reuse of bfd objects.
2240 show debug bfd-cache
2241 Control display of debugging info regarding bfd caching.
2245 Control display of debugging info regarding FreeBSD threads.
2247 set remote multiprocess-extensions-packet
2248 show remote multiprocess-extensions-packet
2249 Set/show the use of the remote protocol multiprocess extensions.
2251 set remote thread-events
2252 show remote thread-events
2253 Set/show the use of thread create/exit events.
2255 set ada print-signatures on|off
2256 show ada print-signatures"
2257 Control whether parameter types and return types are displayed in overloads
2258 selection menus. It is activated (@code{on}) by default.
2262 Controls the maximum size of memory, in bytes, that GDB will
2263 allocate for value contents. Prevents incorrect programs from
2264 causing GDB to allocate overly large buffers. Default is 64k.
2266 * The "disassemble" command accepts a new modifier: /s.
2267 It prints mixed source+disassembly like /m with two differences:
2268 - disassembled instructions are now printed in program order, and
2269 - and source for all relevant files is now printed.
2270 The "/m" option is now considered deprecated: its "source-centric"
2271 output hasn't proved useful in practice.
2273 * The "record instruction-history" command accepts a new modifier: /s.
2274 It behaves exactly like /m and prints mixed source+disassembly.
2276 * The "set scheduler-locking" command supports a new mode "replay".
2277 It behaves like "off" in record mode and like "on" in replay mode.
2279 * Support for various ROM monitors has been removed:
2281 target dbug dBUG ROM monitor for Motorola ColdFire
2282 target picobug Motorola picobug monitor
2283 target dink32 DINK32 ROM monitor for PowerPC
2284 target m32r Renesas M32R/D ROM monitor
2285 target mon2000 mon2000 ROM monitor
2286 target ppcbug PPCBUG ROM monitor for PowerPC
2288 * Support for reading/writing memory and extracting values on architectures
2289 whose memory is addressable in units of any integral multiple of 8 bits.
2292 Allows to break when an Ada exception is handled.
2294 * New remote packets
2297 Indicates that an exec system call was executed.
2299 exec-events feature in qSupported
2300 The qSupported packet allows GDB to request support for exec
2301 events using the new 'gdbfeature' exec-event, and the qSupported
2302 response can contain the corresponding 'stubfeature'. Set and
2303 show commands can be used to display whether these features are enabled.
2306 Equivalent to interrupting with the ^C character, but works in
2309 thread created stop reason (T05 create:...)
2310 Indicates that the thread was just created and is stopped at entry.
2312 thread exit stop reply (w exitcode;tid)
2313 Indicates that the thread has terminated.
2316 Enables/disables thread create and exit event reporting. For
2317 example, this is used in non-stop mode when GDB stops a set of
2318 threads and synchronously waits for the their corresponding stop
2319 replies. Without exit events, if one of the threads exits, GDB
2320 would hang forever not knowing that it should no longer expect a
2321 stop for that same thread.
2324 Indicates that there are no resumed threads left in the target (all
2325 threads are stopped). The remote stub reports support for this stop
2326 reply to GDB's qSupported query.
2329 Enables/disables catching syscalls from the inferior process.
2330 The remote stub reports support for this packet to GDB's qSupported query.
2332 syscall_entry stop reason
2333 Indicates that a syscall was just called.
2335 syscall_return stop reason
2336 Indicates that a syscall just returned.
2338 * Extended-remote exec events
2340 ** GDB now has support for exec events on extended-remote Linux targets.
2341 For such targets with Linux kernels 2.5.46 and later, this enables
2342 follow-exec-mode and exec catchpoints.
2344 set remote exec-event-feature-packet
2345 show remote exec-event-feature-packet
2346 Set/show the use of the remote exec event feature.
2348 * Thread names in remote protocol
2350 The reply to qXfer:threads:read may now include a name attribute for each
2353 * Target remote mode fork and exec events
2355 ** GDB now has support for fork and exec events on target remote mode
2356 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2357 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2358 fork and exec catchpoints.
2360 * Remote syscall events
2362 ** GDB now has support for catch syscall on remote Linux targets,
2363 currently enabled on x86/x86_64 architectures.
2365 set remote catch-syscall-packet
2366 show remote catch-syscall-packet
2367 Set/show the use of the remote catch syscall feature.
2371 ** The -var-set-format command now accepts the zero-hexadecimal
2372 format. It outputs data in hexadecimal format with zero-padding on the
2377 ** gdb.InferiorThread objects have a new attribute "global_num",
2378 which refers to the thread's global thread ID. The existing
2379 "num" attribute now refers to the thread's per-inferior number.
2380 See "Per-inferior thread numbers" above.
2381 ** gdb.InferiorThread objects have a new attribute "inferior", which
2382 is the Inferior object the thread belongs to.
2384 *** Changes in GDB 7.10
2386 * Support for process record-replay and reverse debugging on aarch64*-linux*
2387 targets has been added. GDB now supports recording of A64 instruction set
2388 including advance SIMD instructions.
2390 * Support for Sun's version of the "stabs" debug file format has been removed.
2392 * GDB now honors the content of the file /proc/PID/coredump_filter
2393 (PID is the process ID) on GNU/Linux systems. This file can be used
2394 to specify the types of memory mappings that will be included in a
2395 corefile. For more information, please refer to the manual page of
2396 "core(5)". GDB also has a new command: "set use-coredump-filter
2397 on|off". It allows to set whether GDB will read the content of the
2398 /proc/PID/coredump_filter file when generating a corefile.
2400 * The "info os" command on GNU/Linux can now display information on
2402 "info os cpus" Listing of all cpus/cores on the system
2404 * GDB has two new commands: "set serial parity odd|even|none" and
2405 "show serial parity". These allows to set or show parity for the
2408 * The "info source" command now displays the producer string if it was
2409 present in the debug info. This typically includes the compiler version
2410 and may include things like its command line arguments.
2412 * The "info dll", an alias of the "info sharedlibrary" command,
2413 is now available on all platforms.
2415 * Directory names supplied to the "set sysroot" commands may be
2416 prefixed with "target:" to tell GDB to access shared libraries from
2417 the target system, be it local or remote. This replaces the prefix
2418 "remote:". The default sysroot has been changed from "" to
2419 "target:". "remote:" is automatically converted to "target:" for
2420 backward compatibility.
2422 * The system root specified by "set sysroot" will be prepended to the
2423 filename of the main executable (if reported to GDB as absolute by
2424 the operating system) when starting processes remotely, and when
2425 attaching to already-running local or remote processes.
2427 * GDB now supports automatic location and retrieval of executable
2428 files from remote targets. Remote debugging can now be initiated
2429 using only a "target remote" or "target extended-remote" command
2430 (no "set sysroot" or "file" commands are required). See "New remote
2433 * The "dump" command now supports verilog hex format.
2435 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2437 * On GNU/Linux, GDB and gdbserver are now able to access executable
2438 and shared library files without a "set sysroot" command when
2439 attaching to processes running in different mount namespaces from
2440 the debugger. This makes it possible to attach to processes in
2441 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2442 See "New remote packets" below.
2444 * The "tui reg" command now provides completion for all of the
2445 available register groups, including target specific groups.
2447 * The HISTSIZE environment variable is no longer read when determining
2448 the size of GDB's command history. GDB now instead reads the dedicated
2449 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2450 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2455 ** Memory ports can now be unbuffered.
2459 ** gdb.Objfile objects have a new attribute "username",
2460 which is the name of the objfile as specified by the user,
2461 without, for example, resolving symlinks.
2462 ** You can now write frame unwinders in Python.
2463 ** gdb.Type objects have a new method "optimized_out",
2464 returning optimized out gdb.Value instance of this type.
2465 ** gdb.Value objects have new methods "reference_value" and
2466 "const_value" which return a reference to the value and a
2467 "const" version of the value respectively.
2471 maint print symbol-cache
2472 Print the contents of the symbol cache.
2474 maint print symbol-cache-statistics
2475 Print statistics of symbol cache usage.
2477 maint flush-symbol-cache
2478 Flush the contents of the symbol cache.
2482 Start branch trace recording using Branch Trace Store (BTS) format.
2485 Evaluate expression by using the compiler and print result.
2489 Explicit commands for enabling and disabling tui mode.
2492 set mpx bound on i386 and amd64
2493 Support for bound table investigation on Intel MPX enabled applications.
2497 Start branch trace recording using Intel Processor Trace format.
2500 Print information about branch tracing internals.
2502 maint btrace packet-history
2503 Print the raw branch tracing data.
2505 maint btrace clear-packet-history
2506 Discard the stored raw branch tracing data.
2509 Discard all branch tracing data. It will be fetched and processed
2510 anew by the next "record" command.
2515 Renamed from "set debug dwarf2-die".
2516 show debug dwarf-die
2517 Renamed from "show debug dwarf2-die".
2519 set debug dwarf-read
2520 Renamed from "set debug dwarf2-read".
2521 show debug dwarf-read
2522 Renamed from "show debug dwarf2-read".
2524 maint set dwarf always-disassemble
2525 Renamed from "maint set dwarf2 always-disassemble".
2526 maint show dwarf always-disassemble
2527 Renamed from "maint show dwarf2 always-disassemble".
2529 maint set dwarf max-cache-age
2530 Renamed from "maint set dwarf2 max-cache-age".
2531 maint show dwarf max-cache-age
2532 Renamed from "maint show dwarf2 max-cache-age".
2534 set debug dwarf-line
2535 show debug dwarf-line
2536 Control display of debugging info regarding DWARF line processing.
2539 show max-completions
2540 Set the maximum number of candidates to be considered during
2541 completion. The default value is 200. This limit allows GDB
2542 to avoid generating large completion lists, the computation of
2543 which can cause the debugger to become temporarily unresponsive.
2545 set history remove-duplicates
2546 show history remove-duplicates
2547 Control the removal of duplicate history entries.
2549 maint set symbol-cache-size
2550 maint show symbol-cache-size
2551 Control the size of the symbol cache.
2553 set|show record btrace bts buffer-size
2554 Set and show the size of the ring buffer used for branch tracing in
2556 The obtained size may differ from the requested size. Use "info
2557 record" to see the obtained buffer size.
2559 set debug linux-namespaces
2560 show debug linux-namespaces
2561 Control display of debugging info regarding Linux namespaces.
2563 set|show record btrace pt buffer-size
2564 Set and show the size of the ring buffer used for branch tracing in
2565 Intel Processor Trace format.
2566 The obtained size may differ from the requested size. Use "info
2567 record" to see the obtained buffer size.
2569 maint set|show btrace pt skip-pad
2570 Set and show whether PAD packets are skipped when computing the
2573 * The command 'thread apply all' can now support new option '-ascending'
2574 to call its specified command for all threads in ascending order.
2576 * Python/Guile scripting
2578 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2579 special section named `.debug_gdb_scripts'.
2581 * New remote packets
2583 qXfer:btrace-conf:read
2584 Return the branch trace configuration for the current thread.
2586 Qbtrace-conf:bts:size
2587 Set the requested ring buffer size for branch tracing in BTS format.
2590 Enable Intel Processor Trace-based branch tracing for the current
2591 process. The remote stub reports support for this packet to GDB's
2594 Qbtrace-conf:pt:size
2595 Set the requested ring buffer size for branch tracing in Intel Processor
2599 Indicates a memory breakpoint instruction was executed, irrespective
2600 of whether it was GDB that planted the breakpoint or the breakpoint
2601 is hardcoded in the program. This is required for correct non-stop
2605 Indicates the target stopped for a hardware breakpoint. This is
2606 required for correct non-stop mode operation.
2609 Return information about files on the remote system.
2611 qXfer:exec-file:read
2612 Return the full absolute name of the file that was executed to
2613 create a process running on the remote system.
2616 Select the filesystem on which vFile: operations with filename
2617 arguments will operate. This is required for GDB to be able to
2618 access files on remote targets where the remote stub does not
2619 share a common filesystem with the inferior(s).
2622 Indicates that a fork system call was executed.
2625 Indicates that a vfork system call was executed.
2627 vforkdone stop reason
2628 Indicates that a vfork child of the specified process has executed
2629 an exec or exit, allowing the vfork parent to resume execution.
2631 fork-events and vfork-events features in qSupported
2632 The qSupported packet allows GDB to request support for fork and
2633 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2634 and the qSupported response can contain the corresponding
2635 'stubfeatures'. Set and show commands can be used to display
2636 whether these features are enabled.
2638 * Extended-remote fork events
2640 ** GDB now has support for fork events on extended-remote Linux
2641 targets. For targets with Linux kernels 2.5.60 and later, this
2642 enables follow-fork-mode and detach-on-fork for both fork and
2643 vfork, as well as fork and vfork catchpoints.
2645 * The info record command now shows the recording format and the
2646 branch tracing configuration for the current thread when using
2647 the btrace record target.
2648 For the BTS format, it shows the ring buffer size.
2650 * GDB now has support for DTrace USDT (Userland Static Defined
2651 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2653 * GDB now supports access to vector registers on S/390 GNU/Linux
2656 * Removed command line options
2658 -xdb HP-UX XDB compatibility mode.
2660 * Removed targets and native configurations
2662 HP/PA running HP-UX hppa*-*-hpux*
2663 Itanium running HP-UX ia64-*-hpux*
2665 * New configure options
2668 This configure option allows the user to build GDB with support for
2669 Intel Processor Trace (default: auto). This requires libipt.
2671 --with-libipt-prefix=PATH
2672 Specify the path to the version of libipt that GDB should use.
2673 $PATH/include should contain the intel-pt.h header and
2674 $PATH/lib should contain the libipt.so library.
2676 *** Changes in GDB 7.9.1
2680 ** Xmethods can now specify a result type.
2682 *** Changes in GDB 7.9
2684 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2688 ** You can now access frame registers from Python scripts.
2689 ** New attribute 'producer' for gdb.Symtab objects.
2690 ** gdb.Objfile objects have a new attribute "progspace",
2691 which is the gdb.Progspace object of the containing program space.
2692 ** gdb.Objfile objects have a new attribute "owner".
2693 ** gdb.Objfile objects have a new attribute "build_id",
2694 which is the build ID generated when the file was built.
2695 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2696 ** A new event "gdb.clear_objfiles" has been added, triggered when
2697 selecting a new file to debug.
2698 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2699 ** New function gdb.lookup_objfile.
2701 New events which are triggered when GDB modifies the state of the
2704 ** gdb.events.inferior_call_pre: Function call is about to be made.
2705 ** gdb.events.inferior_call_post: Function call has just been made.
2706 ** gdb.events.memory_changed: A memory location has been altered.
2707 ** gdb.events.register_changed: A register has been altered.
2709 * New Python-based convenience functions:
2711 ** $_caller_is(name [, number_of_frames])
2712 ** $_caller_matches(regexp [, number_of_frames])
2713 ** $_any_caller_is(name [, number_of_frames])
2714 ** $_any_caller_matches(regexp [, number_of_frames])
2716 * GDB now supports the compilation and injection of source code into
2717 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2718 to compile the source code to object code, and if successful, inject
2719 and execute that code within the current context of the inferior.
2720 Currently the C language is supported. The commands used to
2721 interface with this new feature are:
2723 compile code [-raw|-r] [--] [source code]
2724 compile file [-raw|-r] filename
2728 demangle [-l language] [--] name
2729 Demangle "name" in the specified language, or the current language
2730 if elided. This command is renamed from the "maint demangle" command.
2731 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2732 as "maint demangler-warning".
2734 queue-signal signal-name-or-number
2735 Queue a signal to be delivered to the thread when it is resumed.
2737 add-auto-load-scripts-directory directory
2738 Add entries to the list of directories from which to load auto-loaded
2741 maint print user-registers
2742 List all currently available "user" registers.
2744 compile code [-r|-raw] [--] [source code]
2745 Compile, inject, and execute in the inferior the executable object
2746 code produced by compiling the provided source code.
2748 compile file [-r|-raw] filename
2749 Compile and inject into the inferior the executable object code
2750 produced by compiling the source code stored in the filename
2753 * On resume, GDB now always passes the signal the program had stopped
2754 for to the thread the signal was sent to, even if the user changed
2755 threads before resuming. Previously GDB would often (but not
2756 always) deliver the signal to the thread that happens to be current
2759 * Conversely, the "signal" command now consistently delivers the
2760 requested signal to the current thread. GDB now asks for
2761 confirmation if the program had stopped for a signal and the user
2762 switched threads meanwhile.
2764 * "breakpoint always-inserted" modes "off" and "auto" merged.
2766 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2767 won't remove breakpoints from the target until all threads stop,
2768 even in non-stop mode. The "auto" mode has been removed, and "off"
2769 is now the default mode.
2773 set debug symbol-lookup
2774 show debug symbol-lookup
2775 Control display of debugging info regarding symbol lookup.
2779 ** The -list-thread-groups command outputs an exit-code field for
2780 inferiors that have exited.
2784 MIPS SDE mips*-sde*-elf*
2788 Support for these obsolete configurations has been removed.
2790 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2791 SGI Irix-5.x mips-*-irix5*
2792 SGI Irix-6.x mips-*-irix6*
2793 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2794 VAX running Ultrix vax-*-ultrix*
2796 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2797 and "assf"), have been removed. Use the "sharedlibrary" command, or
2798 its alias "share", instead.
2800 *** Changes in GDB 7.8
2802 * New command line options
2805 This is an alias for the --data-directory option.
2807 * GDB supports printing and modifying of variable length automatic arrays
2808 as specified in ISO C99.
2810 * The ARM simulator now supports instruction level tracing
2811 with or without disassembly.
2815 GDB now has support for scripting using Guile. Whether this is
2816 available is determined at configure time.
2817 Guile version 2.0 or greater is required.
2818 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
2820 * New commands (for set/show, see "New options" below)
2824 Invoke CODE by passing it to the Guile interpreter.
2828 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
2830 info auto-load guile-scripts [regexp]
2831 Print the list of automatically loaded Guile scripts.
2833 * The source command is now capable of sourcing Guile scripts.
2834 This feature is dependent on the debugger being built with Guile support.
2838 set print symbol-loading (off|brief|full)
2839 show print symbol-loading
2840 Control whether to print informational messages when loading symbol
2841 information for a file. The default is "full", but when debugging
2842 programs with large numbers of shared libraries the amount of output
2843 becomes less useful.
2845 set guile print-stack (none|message|full)
2846 show guile print-stack
2847 Show a stack trace when an error is encountered in a Guile script.
2849 set auto-load guile-scripts (on|off)
2850 show auto-load guile-scripts
2851 Control auto-loading of Guile script files.
2853 maint ada set ignore-descriptive-types (on|off)
2854 maint ada show ignore-descriptive-types
2855 Control whether the debugger should ignore descriptive types in Ada
2856 programs. The default is not to ignore the descriptive types. See
2857 the user manual for more details on descriptive types and the intended
2858 usage of this option.
2860 set auto-connect-native-target
2862 Control whether GDB is allowed to automatically connect to the
2863 native target for the run, attach, etc. commands when not connected
2864 to any target yet. See also "target native" below.
2866 set record btrace replay-memory-access (read-only|read-write)
2867 show record btrace replay-memory-access
2868 Control what memory accesses are allowed during replay.
2870 maint set target-async (on|off)
2871 maint show target-async
2872 This controls whether GDB targets operate in synchronous or
2873 asynchronous mode. Normally the default is asynchronous, if it is
2874 available; but this can be changed to more easily debug problems
2875 occurring only in synchronous mode.
2877 set mi-async (on|off)
2879 Control whether MI asynchronous mode is preferred. This supersedes
2880 "set target-async" of previous GDB versions.
2882 * "set target-async" is deprecated as a CLI option and is now an alias
2883 for "set mi-async" (only puts MI into async mode).
2885 * Background execution commands (e.g., "c&", "s&", etc.) are now
2886 possible ``out of the box'' if the target supports them. Previously
2887 the user would need to explicitly enable the possibility with the
2888 "set target-async on" command.
2890 * New features in the GDB remote stub, GDBserver
2892 ** New option --debug-format=option1[,option2,...] allows one to add
2893 additional text to each output. At present only timestamps
2894 are supported: --debug-format=timestamps.
2895 Timestamps can also be turned on with the
2896 "monitor set debug-format timestamps" command from GDB.
2898 * The 'record instruction-history' command now starts counting instructions
2899 at one. This also affects the instruction ranges reported by the
2900 'record function-call-history' command when given the /i modifier.
2902 * The command 'record function-call-history' supports a new modifier '/c' to
2903 indent the function names based on their call stack depth.
2904 The fields for the '/i' and '/l' modifier have been reordered.
2905 The source line range is now prefixed with 'at'.
2906 The instruction range is now prefixed with 'inst'.
2907 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
2908 "record instruction-history" and "list" commands.
2910 * The ranges given as arguments to the 'record function-call-history' and
2911 'record instruction-history' commands are now inclusive.
2913 * The btrace record target now supports the 'record goto' command.
2914 For locations inside the execution trace, the back trace is computed
2915 based on the information stored in the execution trace.
2917 * The btrace record target supports limited reverse execution and replay.
2918 The target does not record data and therefore does not allow reading
2919 memory or registers.
2921 * The "catch syscall" command now works on s390*-linux* targets.
2923 * The "compare-sections" command is no longer specific to target
2924 remote. It now works with all targets.
2926 * All native targets are now consistently called "native".
2927 Consequently, the "target child", "target GNU", "target djgpp",
2928 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
2929 commands have been replaced with "target native". The QNX/NTO port
2930 leaves the "procfs" target in place and adds a "native" target for
2931 consistency with other ports. The impact on users should be minimal
2932 as these commands previously either throwed an error, or were
2933 no-ops. The target's name is visible in the output of the following
2934 commands: "help target", "info target", "info files", "maint print
2937 * The "target native" command now connects to the native target. This
2938 can be used to launch native programs even when "set
2939 auto-connect-native-target" is set to off.
2941 * GDB now supports access to Intel MPX registers on GNU/Linux.
2943 * Support for Intel AVX-512 registers on GNU/Linux.
2944 Support displaying and modifying Intel AVX-512 registers
2945 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
2947 * New remote packets
2949 qXfer:btrace:read's annex
2950 The qXfer:btrace:read packet supports a new annex 'delta' to read
2951 branch trace incrementally.
2955 ** Valid Python operations on gdb.Value objects representing
2956 structs/classes invoke the corresponding overloaded operators if
2958 ** New `Xmethods' feature in the Python API. Xmethods are
2959 additional methods or replacements for existing methods of a C++
2960 class. This feature is useful for those cases where a method
2961 defined in C++ source code could be inlined or optimized out by
2962 the compiler, making it unavailable to GDB.
2965 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
2967 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2968 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
2969 its alias "share", instead.
2971 * The commands "set remotebaud" and "show remotebaud" are no longer
2972 supported. Use "set serial baud" and "show serial baud" (respectively)
2977 ** A new option "-gdb-set mi-async" replaces "-gdb-set
2978 target-async". The latter is left as a deprecated alias of the
2979 former for backward compatibility. If the target supports it,
2980 CLI background execution commands are now always possible by
2981 default, independently of whether the frontend stated a
2982 preference for asynchronous execution with "-gdb-set mi-async".
2983 Previously "-gdb-set target-async off" affected both MI execution
2984 commands and CLI execution commands.
2986 *** Changes in GDB 7.7
2988 * Improved support for process record-replay and reverse debugging on
2989 arm*-linux* targets. Support for thumb32 and syscall instruction
2990 recording has been added.
2992 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
2994 * GDB now supports Fission DWP file format version 2.
2995 http://gcc.gnu.org/wiki/DebugFission
2997 * New convenience function "$_isvoid", to check whether an expression
2998 is void. A void expression is an expression where the type of the
2999 result is "void". For example, some convenience variables may be
3000 "void" when evaluated (e.g., "$_exitcode" before the execution of
3001 the program being debugged; or an undefined convenience variable).
3002 Another example, when calling a function whose return type is
3005 * The "maintenance print objfiles" command now takes an optional regexp.
3007 * The "catch syscall" command now works on arm*-linux* targets.
3009 * GDB now consistently shows "<not saved>" when printing values of
3010 registers the debug info indicates have not been saved in the frame
3011 and there's nowhere to retrieve them from
3012 (callee-saved/call-clobbered registers):
3017 (gdb) info registers rax
3020 Before, the former would print "<optimized out>", and the latter
3021 "*value not available*".
3023 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3028 ** Frame filters and frame decorators have been added.
3029 ** Temporary breakpoints are now supported.
3030 ** Line tables representation has been added.
3031 ** New attribute 'parent_type' for gdb.Field objects.
3032 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3033 ** New attribute 'name' for gdb.Type objects.
3037 Nios II ELF nios2*-*-elf
3038 Nios II GNU/Linux nios2*-*-linux
3039 Texas Instruments MSP430 msp430*-*-elf
3041 * Removed native configurations
3043 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3044 been removed. ELF variants of these configurations are kept supported.
3046 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3047 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3048 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3049 i[34567]86-*-openbsd3.[0-3]
3050 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3051 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3052 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3056 Like "catch throw", but catches a re-thrown exception.
3057 maint check-psymtabs
3058 Renamed from old "maint check-symtabs".
3060 Perform consistency checks on symtabs.
3061 maint expand-symtabs
3062 Expand symtabs matching an optional regexp.
3065 Display the details of GDB configure-time options.
3067 maint set|show per-command
3068 maint set|show per-command space
3069 maint set|show per-command time
3070 maint set|show per-command symtab
3071 Enable display of per-command gdb resource usage.
3073 remove-symbol-file FILENAME
3074 remove-symbol-file -a ADDRESS
3075 Remove a symbol file added via add-symbol-file. The file to remove
3076 can be identified by its filename or by an address that lies within
3077 the boundaries of this symbol file in memory.
3080 info exceptions REGEXP
3081 Display the list of Ada exceptions defined in the program being
3082 debugged. If provided, only the exceptions whose names match REGEXP
3087 set debug symfile off|on
3089 Control display of debugging info regarding reading symbol files and
3090 symbol tables within those files
3092 set print raw frame-arguments
3093 show print raw frame-arguments
3094 Set/show whether to print frame arguments in raw mode,
3095 disregarding any defined pretty-printers.
3097 set remote trace-status-packet
3098 show remote trace-status-packet
3099 Set/show the use of remote protocol qTStatus packet.
3103 Control display of debugging messages related to Nios II targets.
3107 Control whether target-assisted range stepping is enabled.
3109 set startup-with-shell
3110 show startup-with-shell
3111 Specifies whether Unix child processes are started via a shell or
3116 Use the target memory cache for accesses to the code segment. This
3117 improves performance of remote debugging (particularly disassembly).
3119 * You can now use a literal value 'unlimited' for options that
3120 interpret 0 or -1 as meaning "unlimited". E.g., "set
3121 trace-buffer-size unlimited" is now an alias for "set
3122 trace-buffer-size -1" and "set height unlimited" is now an alias for
3125 * The "set debug symtab-create" debugging option of GDB has been changed to
3126 accept a verbosity level. 0 means "off", 1 provides basic debugging
3127 output, and values of 2 or greater provides more verbose output.
3129 * New command-line options
3131 Display the details of GDB configure-time options.
3133 * The command 'tsave' can now support new option '-ctf' to save trace
3134 buffer in Common Trace Format.
3136 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3139 * GDB now implements the C++ 'typeid' operator.
3141 * The new convenience variable $_exception holds the exception being
3142 thrown or caught at an exception-related catchpoint.
3144 * The exception-related catchpoints, like "catch throw", now accept a
3145 regular expression which can be used to filter exceptions by type.
3147 * The new convenience variable $_exitsignal is automatically set to
3148 the terminating signal number when the program being debugged dies
3149 due to an uncaught signal.
3153 ** All MI commands now accept an optional "--language" option.
3154 Support for this feature can be verified by using the "-list-features"
3155 command, which should contain "language-option".
3157 ** The new command -info-gdb-mi-command allows the user to determine
3158 whether a GDB/MI command is supported or not.
3160 ** The "^error" result record returned when trying to execute an undefined
3161 GDB/MI command now provides a variable named "code" whose content is the
3162 "undefined-command" error code. Support for this feature can be verified
3163 by using the "-list-features" command, which should contain
3164 "undefined-command-error-code".
3166 ** The -trace-save MI command can optionally save trace buffer in Common
3169 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3171 ** The command -data-list-register-values now accepts an optional
3172 "--skip-unavailable" option. When used, only the available registers
3175 ** The new command -trace-frame-collected dumps collected variables,
3176 computed expressions, tvars, memory and registers in a traceframe.
3178 ** The commands -stack-list-locals, -stack-list-arguments and
3179 -stack-list-variables now accept an option "--skip-unavailable".
3180 When used, only the available locals or arguments are displayed.
3182 ** The -exec-run command now accepts an optional "--start" option.
3183 When used, the command follows the same semantics as the "start"
3184 command, stopping the program's execution at the start of its
3185 main subprogram. Support for this feature can be verified using
3186 the "-list-features" command, which should contain
3187 "exec-run-start-option".
3189 ** The new commands -catch-assert and -catch-exceptions insert
3190 catchpoints stopping the program when Ada exceptions are raised.
3192 ** The new command -info-ada-exceptions provides the equivalent of
3193 the new "info exceptions" command.
3195 * New system-wide configuration scripts
3196 A GDB installation now provides scripts suitable for use as system-wide
3197 configuration scripts for the following systems:
3201 * GDB now supports target-assigned range stepping with remote targets.
3202 This improves the performance of stepping source lines by reducing
3203 the number of control packets from/to GDB. See "New remote packets"
3206 * GDB now understands the element 'tvar' in the XML traceframe info.
3207 It has the id of the collected trace state variables.
3209 * On S/390 targets that provide the transactional-execution feature,
3210 the program interruption transaction diagnostic block (TDB) is now
3211 represented as a number of additional "registers" in GDB.
3213 * New remote packets
3217 The vCont packet supports a new 'r' action, that tells the remote
3218 stub to step through an address range itself, without GDB
3219 involvemement at each single-step.
3221 qXfer:libraries-svr4:read's annex
3222 The previously unused annex of the qXfer:libraries-svr4:read packet
3223 is now used to support passing an argument list. The remote stub
3224 reports support for this argument list to GDB's qSupported query.
3225 The defined arguments are "start" and "prev", used to reduce work
3226 necessary for library list updating, resulting in significant
3229 * New features in the GDB remote stub, GDBserver
3231 ** GDBserver now supports target-assisted range stepping. Currently
3232 enabled on x86/x86_64 GNU/Linux targets.
3234 ** GDBserver now adds element 'tvar' in the XML in the reply to
3235 'qXfer:traceframe-info:read'. It has the id of the collected
3236 trace state variables.
3238 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3241 * New 'z' formatter for printing and examining memory, this displays the
3242 value as hexadecimal zero padded on the left to the size of the type.
3244 * GDB can now use Windows x64 unwinding data.
3246 * The "set remotebaud" command has been replaced by "set serial baud".
3247 Similarly, "show remotebaud" has been replaced by "show serial baud".
3248 The "set remotebaud" and "show remotebaud" commands are still available
3249 to provide backward compatibility with older versions of GDB.
3251 *** Changes in GDB 7.6
3253 * Target record has been renamed to record-full.
3254 Record/replay is now enabled with the "record full" command.
3255 This also affects settings that are associated with full record/replay
3256 that have been moved from "set/show record" to "set/show record full":
3258 set|show record full insn-number-max
3259 set|show record full stop-at-limit
3260 set|show record full memory-query
3262 * A new record target "record-btrace" has been added. The new target
3263 uses hardware support to record the control-flow of a process. It
3264 does not support replaying the execution, but it implements the
3265 below new commands for investigating the recorded execution log.
3266 This new recording method can be enabled using:
3270 The "record-btrace" target is only available on Intel Atom processors
3271 and requires a Linux kernel 2.6.32 or later.
3273 * Two new commands have been added for record/replay to give information
3274 about the recorded execution without having to replay the execution.
3275 The commands are only supported by "record btrace".
3277 record instruction-history prints the execution history at
3278 instruction granularity
3280 record function-call-history prints the execution history at
3281 function granularity
3283 * New native configurations
3285 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3286 FreeBSD/powerpc powerpc*-*-freebsd
3287 x86_64/Cygwin x86_64-*-cygwin*
3288 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3292 ARM AArch64 aarch64*-*-elf
3293 ARM AArch64 GNU/Linux aarch64*-*-linux
3294 Lynx 178 PowerPC powerpc-*-lynx*178
3295 x86_64/Cygwin x86_64-*-cygwin*
3296 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3298 * If the configured location of system.gdbinit file (as given by the
3299 --with-system-gdbinit option at configure time) is in the
3300 data-directory (as specified by --with-gdb-datadir at configure
3301 time) or in one of its subdirectories, then GDB will look for the
3302 system-wide init file in the directory specified by the
3303 --data-directory command-line option.
3305 * New command line options:
3307 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3308 other initialization files, unlike -nx which disables all of them.
3310 * Removed command line options
3312 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3315 * The 'ptype' and 'whatis' commands now accept an argument to control
3318 * 'info proc' now works on some core files.
3322 ** Vectors can be created with gdb.Type.vector.
3324 ** Python's atexit.register now works in GDB.
3326 ** Types can be pretty-printed via a Python API.
3328 ** Python 3 is now supported (in addition to Python 2.4 or later)
3330 ** New class gdb.Architecture exposes GDB's internal representation
3331 of architecture in the Python API.
3333 ** New method Frame.architecture returns the gdb.Architecture object
3334 corresponding to the frame's architecture.
3336 * New Python-based convenience functions:
3338 ** $_memeq(buf1, buf2, length)
3339 ** $_streq(str1, str2)
3341 ** $_regex(str, regex)
3343 * The 'cd' command now defaults to using '~' (the home directory) if not
3346 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3347 default for GCC since November 2000.
3349 * The command 'forward-search' can now be abbreviated as 'fo'.
3351 * The command 'info tracepoints' can now display 'installed on target'
3352 or 'not installed on target' for each non-pending location of tracepoint.
3354 * New configure options
3356 --enable-libmcheck/--disable-libmcheck
3357 By default, development versions are built with -lmcheck on hosts
3358 that support it, in order to help track memory corruption issues.
3359 Release versions, on the other hand, are built without -lmcheck
3360 by default. The --enable-libmcheck/--disable-libmcheck configure
3361 options allow the user to override that default.
3362 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3363 This configure option allows the user to build GDB with
3364 libbabeltrace using which GDB can read Common Trace Format data.
3366 * New commands (for set/show, see "New options" below)
3369 Catch signals. This is similar to "handle", but allows commands and
3370 conditions to be attached.
3373 List the BFDs known to GDB.
3375 python-interactive [command]
3377 Start a Python interactive prompt, or evaluate the optional command
3378 and print the result of expressions.
3381 "py" is a new alias for "python".
3383 enable type-printer [name]...
3384 disable type-printer [name]...
3385 Enable or disable type printers.
3389 ** For the Renesas Super-H architecture, the "regs" command has been removed
3390 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3395 set print type methods (on|off)
3396 show print type methods
3397 Control whether method declarations are displayed by "ptype".
3398 The default is to show them.
3400 set print type typedefs (on|off)
3401 show print type typedefs
3402 Control whether typedef definitions are displayed by "ptype".
3403 The default is to show them.
3405 set filename-display basename|relative|absolute
3406 show filename-display
3407 Control the way in which filenames is displayed.
3408 The default is "relative", which preserves previous behavior.
3410 set trace-buffer-size
3411 show trace-buffer-size
3412 Request target to change the size of trace buffer.
3414 set remote trace-buffer-size-packet auto|on|off
3415 show remote trace-buffer-size-packet
3416 Control the use of the remote protocol `QTBuffer:size' packet.
3420 Control display of debugging messages related to ARM AArch64.
3423 set debug coff-pe-read
3424 show debug coff-pe-read
3425 Control display of debugging messages related to reading of COFF/PE
3430 Control display of debugging messages related to Mach-O symbols
3433 set debug notification
3434 show debug notification
3435 Control display of debugging info for async remote notification.
3439 ** Command parameter changes are now notified using new async record
3440 "=cmd-param-changed".
3441 ** Trace frame changes caused by command "tfind" are now notified using
3442 new async record "=traceframe-changed".
3443 ** The creation, deletion and modification of trace state variables
3444 are now notified using new async records "=tsv-created",
3445 "=tsv-deleted" and "=tsv-modified".
3446 ** The start and stop of process record are now notified using new
3447 async record "=record-started" and "=record-stopped".
3448 ** Memory changes are now notified using new async record
3450 ** The data-disassemble command response will include a "fullname" field
3451 containing the absolute file name when source has been requested.
3452 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3453 command, to allow pattern filling of memory areas.
3454 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3455 library load/unload events.
3456 ** The response to breakpoint commands and breakpoint async records
3457 includes an "installed" field containing a boolean state about each
3458 non-pending tracepoint location is whether installed on target or not.
3459 ** Output of the "-trace-status" command includes a "trace-file" field
3460 containing the name of the trace file being examined. This field is
3461 optional, and only present when examining a trace file.
3462 ** The "fullname" field is now always present along with the "file" field,
3463 even if the file cannot be found by GDB.
3465 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3466 You must have the LZMA library available when configuring GDB for this
3467 feature to be enabled. For more information, see:
3468 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3470 * New remote packets
3473 Set the size of trace buffer. The remote stub reports support for this
3474 packet to gdb's qSupported query.
3477 Enable Branch Trace Store (BTS)-based branch tracing for the current
3478 thread. The remote stub reports support for this packet to gdb's
3482 Disable branch tracing for the current thread. The remote stub reports
3483 support for this packet to gdb's qSupported query.
3486 Read the traced branches for the current thread. The remote stub
3487 reports support for this packet to gdb's qSupported query.
3489 *** Changes in GDB 7.5
3491 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3492 for more x32 ABI info.
3494 * GDB now supports access to MIPS DSP registers on Linux targets.
3496 * GDB now supports debugging microMIPS binaries.
3498 * The "info os" command on GNU/Linux can now display information on
3499 several new classes of objects managed by the operating system:
3500 "info os procgroups" lists process groups
3501 "info os files" lists file descriptors
3502 "info os sockets" lists internet-domain sockets
3503 "info os shm" lists shared-memory regions
3504 "info os semaphores" lists semaphores
3505 "info os msg" lists message queues
3506 "info os modules" lists loaded kernel modules
3508 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3509 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3510 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3511 options and inspect the probe arguments using the new $_probe_arg family
3512 of convenience variables. You can obtain more information about SystemTap
3513 in <http://sourceware.org/systemtap/>.
3515 * GDB now supports reversible debugging on ARM, it allows you to
3516 debug basic ARM and THUMB instructions, and provides
3517 record/replay support.
3519 * The option "symbol-reloading" has been deleted as it is no longer used.
3523 ** GDB commands implemented in Python can now be put in command class
3526 ** The "maint set python print-stack on|off" is now deleted.
3528 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3529 apply "flag enum"-style pretty-printing to any enum.
3531 ** gdb.lookup_symbol can now work when there is no current frame.
3533 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3534 the source at which the symbol was defined.
3536 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3537 method 'value'. The former indicates whether the symbol needs a
3538 frame in order to compute its value, and the latter computes the
3541 ** A new method 'referenced_value' on gdb.Value objects which can
3542 dereference pointer as well as C++ reference values.
3544 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3545 which return the global and static blocks (as gdb.Block objects),
3546 of the underlying symbol table, respectively.
3548 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3549 object associated with a PC value.
3551 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3552 of the address range occupied by code for the current source line.
3554 * Go language support.
3555 GDB now supports debugging programs written in the Go programming
3558 * GDBserver now supports stdio connections.
3559 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3561 * The binary "gdbtui" can no longer be built or installed.
3562 Use "gdb -tui" instead.
3564 * GDB will now print "flag" enums specially. A flag enum is one where
3565 all the enumerator values have no bits in common when pairwise
3566 "and"ed. When printing a value whose type is a flag enum, GDB will
3567 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3568 (gdb) print (enum E) 3
3571 * The filename part of a linespec will now match trailing components
3572 of a source file name. For example, "break gcc/expr.c:1000" will
3573 now set a breakpoint in build/gcc/expr.c, but not
3574 build/libcpp/expr.c.
3576 * The "info proc" and "generate-core-file" commands will now also
3577 work on remote targets connected to GDBserver on Linux.
3579 * The command "info catch" has been removed. It has been disabled
3580 since December 2007.
3582 * The "catch exception" and "catch assert" commands now accept
3583 a condition at the end of the command, much like the "break"
3584 command does. For instance:
3586 (gdb) catch exception Constraint_Error if Barrier = True
3588 Previously, it was possible to add a condition to such catchpoints,
3589 but it had to be done as a second step, after the catchpoint had been
3590 created, using the "condition" command.
3592 * The "info static-tracepoint-marker" command will now also work on
3593 native Linux targets with in-process agent.
3595 * GDB can now set breakpoints on inlined functions.
3597 * The .gdb_index section has been updated to include symbols for
3598 inlined functions. GDB will ignore older .gdb_index sections by
3599 default, which could cause symbol files to be loaded more slowly
3600 until their .gdb_index sections can be recreated. The new command
3601 "set use-deprecated-index-sections on" will cause GDB to use any older
3602 .gdb_index sections it finds. This will restore performance, but the
3603 ability to set breakpoints on inlined functions will be lost in symbol
3604 files with older .gdb_index sections.
3606 The .gdb_index section has also been updated to record more information
3607 about each symbol. This speeds up the "info variables", "info functions"
3608 and "info types" commands when used with programs having the .gdb_index
3609 section, as well as speeding up debugging with shared libraries using
3610 the .gdb_index section.
3612 * Ada support for GDB/MI Variable Objects has been added.
3614 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3619 ** New command -info-os is the MI equivalent of "info os".
3621 ** Output logs ("set logging" and related) now include MI output.
3625 ** "set use-deprecated-index-sections on|off"
3626 "show use-deprecated-index-sections on|off"
3627 Controls the use of deprecated .gdb_index sections.
3629 ** "catch load" and "catch unload" can be used to stop when a shared
3630 library is loaded or unloaded, respectively.
3632 ** "enable count" can be used to auto-disable a breakpoint after
3635 ** "info vtbl" can be used to show the virtual method tables for
3636 C++ and Java objects.
3638 ** "explore" and its sub commands "explore value" and "explore type"
3639 can be used to recursively explore values and types of
3640 expressions. These commands are available only if GDB is
3641 configured with '--with-python'.
3643 ** "info auto-load" shows status of all kinds of auto-loaded files,
3644 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3645 sequences of commands files, "info auto-load python-scripts"
3646 shows status of auto-loading Python script files,
3647 "info auto-load local-gdbinit" shows status of loading init file
3648 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3649 status of inferior specific thread debugging shared library loading.
3651 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3652 and "show auto-load-scripts" commands have been deprecated, use their
3653 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3654 and "show auto-load python-scripts" counterparts instead.
3656 ** "dprintf location,format,args..." creates a dynamic printf, which
3657 is basically a breakpoint that does a printf and immediately
3658 resumes your program's execution, so it is like a printf that you
3659 can insert dynamically at runtime instead of at compiletime.
3661 ** "set print symbol"
3663 Controls whether GDB attempts to display the symbol, if any,
3664 corresponding to addresses it prints. This defaults to "on", but
3665 you can set it to "off" to restore GDB's previous behavior.
3667 * Deprecated commands
3669 ** For the Renesas Super-H architecture, the "regs" command has been
3670 deprecated, and "info all-registers" should be used instead.
3674 Renesas RL78 rl78-*-elf
3675 HP OpenVMS ia64 ia64-hp-openvms*
3677 * GDBserver supports evaluation of breakpoint conditions. When
3678 support is advertised by GDBserver, GDB may be told to send the
3679 breakpoint conditions in bytecode form to GDBserver. GDBserver
3680 will only report the breakpoint trigger to GDB when its condition
3685 set mips compression
3686 show mips compression
3687 Select the compressed ISA encoding used in functions that have no symbol
3688 information available. The encoding can be set to either of:
3691 and is updated automatically from ELF file flags if available.
3693 set breakpoint condition-evaluation
3694 show breakpoint condition-evaluation
3695 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3696 GDBserver ("target"). Default option "auto" chooses the most efficient
3698 This option can improve debugger efficiency depending on the speed of the
3702 Disable auto-loading globally.
3705 Show auto-loading setting of all kinds of auto-loaded files.
3707 set auto-load gdb-scripts on|off
3708 show auto-load gdb-scripts
3709 Control auto-loading of GDB canned sequences of commands files.
3711 set auto-load python-scripts on|off
3712 show auto-load python-scripts
3713 Control auto-loading of Python script files.
3715 set auto-load local-gdbinit on|off
3716 show auto-load local-gdbinit
3717 Control loading of init file (.gdbinit) from current directory.
3719 set auto-load libthread-db on|off
3720 show auto-load libthread-db
3721 Control auto-loading of inferior specific thread debugging shared library.
3723 set auto-load scripts-directory <dir1>[:<dir2>...]
3724 show auto-load scripts-directory
3725 Set a list of directories from which to load auto-loaded scripts.
3726 Automatically loaded Python scripts and GDB scripts are located in one
3727 of the directories listed by this option.
3728 The delimiter (':' above) may differ according to the host platform.
3730 set auto-load safe-path <dir1>[:<dir2>...]
3731 show auto-load safe-path
3732 Set a list of directories from which it is safe to auto-load files.
3733 The delimiter (':' above) may differ according to the host platform.
3735 set debug auto-load on|off
3736 show debug auto-load
3737 Control display of debugging info for auto-loading the files above.
3739 set dprintf-style gdb|call|agent
3741 Control the way in which a dynamic printf is performed; "gdb"
3742 requests a GDB printf command, while "call" causes dprintf to call a
3743 function in the inferior. "agent" requests that the target agent
3744 (such as GDBserver) do the printing.
3746 set dprintf-function <expr>
3747 show dprintf-function
3748 set dprintf-channel <expr>
3749 show dprintf-channel
3750 Set the function and optional first argument to the call when using
3751 the "call" style of dynamic printf.
3753 set disconnected-dprintf on|off
3754 show disconnected-dprintf
3755 Control whether agent-style dynamic printfs continue to be in effect
3756 after GDB disconnects.
3758 * New configure options
3760 --with-auto-load-dir
3761 Configure default value for the 'set auto-load scripts-directory'
3762 setting above. It defaults to '$debugdir:$datadir/auto-load',
3763 $debugdir representing global debugging info directories (available
3764 via 'show debug-file-directory') and $datadir representing GDB's data
3765 directory (available via 'show data-directory').
3767 --with-auto-load-safe-path
3768 Configure default value for the 'set auto-load safe-path' setting
3769 above. It defaults to the --with-auto-load-dir setting.
3771 --without-auto-load-safe-path
3772 Set 'set auto-load safe-path' to '/', effectively disabling this
3775 * New remote packets
3777 z0/z1 conditional breakpoints extension
3779 The z0/z1 breakpoint insertion packets have been extended to carry
3780 a list of conditional expressions over to the remote stub depending on the
3781 condition evaluation mode. The use of this extension can be controlled
3782 via the "set remote conditional-breakpoints-packet" command.
3786 Specify the signals which the remote stub may pass to the debugged
3787 program without GDB involvement.
3789 * New command line options
3791 --init-command=FILE, -ix Like --command, -x but execute it
3792 before loading inferior.
3793 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3794 execute it before loading inferior.
3796 *** Changes in GDB 7.4
3798 * GDB now handles ambiguous linespecs more consistently; the existing
3799 FILE:LINE support has been expanded to other types of linespecs. A
3800 breakpoint will now be set on all matching locations in all
3801 inferiors, and locations will be added or removed according to
3804 * GDB now allows you to skip uninteresting functions and files when
3805 stepping with the "skip function" and "skip file" commands.
3807 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3808 and "show remote hardware-watchpoint-length-limit". These allows to
3809 set or show the maximum length limit (in bytes) of a remote
3810 target hardware watchpoint.
3812 This allows e.g. to use "unlimited" hardware watchpoints with the
3813 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3814 watchpoints are slower than real hardware watchpoints but are
3815 significantly faster than gdb software watchpoints.
3819 ** The register_pretty_printer function in module gdb.printing now takes
3820 an optional `replace' argument. If True, the new printer replaces any
3823 ** The "maint set python print-stack on|off" command has been
3824 deprecated and will be deleted in GDB 7.5.
3825 A new command: "set python print-stack none|full|message" has
3826 replaced it. Additionally, the default for "print-stack" is
3827 now "message", which just prints the error message without
3830 ** A prompt substitution hook (prompt_hook) is now available to the
3833 ** A new Python module, gdb.prompt has been added to the GDB Python
3834 modules library. This module provides functionality for
3835 escape sequences in prompts (used by set/show
3836 extended-prompt). These escape sequences are replaced by their
3837 corresponding value.
3839 ** Python commands and convenience-functions located in
3840 'data-directory'/python/gdb/command and
3841 'data-directory'/python/gdb/function are now automatically loaded
3844 ** Blocks now provide four new attributes. global_block and
3845 static_block will return the global and static blocks
3846 respectively. is_static and is_global are boolean attributes
3847 that indicate if the block is one of those two types.
3849 ** Symbols now provide the "type" attribute, the type of the symbol.
3851 ** The "gdb.breakpoint" function has been deprecated in favor of
3854 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
3855 of a function. This class is based on the "finish" command
3856 available in the CLI.
3858 ** Type objects for struct and union types now allow access to
3859 the fields using standard Python dictionary (mapping) methods.
3860 For example, "some_type['myfield']" now works, as does
3861 "some_type.items()".
3863 ** A new event "gdb.new_objfile" has been added, triggered by loading a
3866 ** A new function, "deep_items" has been added to the gdb.types
3867 module in the GDB Python modules library. This function returns
3868 an iterator over the fields of a struct or union type. Unlike
3869 the standard Python "iteritems" method, it will recursively traverse
3870 any anonymous fields.
3874 ** "*stopped" events can report several new "reason"s, such as
3877 ** Breakpoint changes are now notified using new async records, like
3878 "=breakpoint-modified".
3880 ** New command -ada-task-info.
3882 * libthread-db-search-path now supports two special values: $sdir and $pdir.
3883 $sdir specifies the default system locations of shared libraries.
3884 $pdir specifies the directory where the libpthread used by the application
3887 GDB no longer looks in $sdir and $pdir after it has searched the directories
3888 mentioned in libthread-db-search-path. If you want to search those
3889 directories, they must be specified in libthread-db-search-path.
3890 The default value of libthread-db-search-path on GNU/Linux and Solaris
3891 systems is now "$sdir:$pdir".
3893 $pdir is not supported by gdbserver, it is currently ignored.
3894 $sdir is supported by gdbserver.
3896 * New configure option --with-iconv-bin.
3897 When using the internationalization support like the one in the GNU C
3898 library, GDB will invoke the "iconv" program to get a list of supported
3899 character sets. If this program lives in a non-standard location, one can
3900 use this option to specify where to find it.
3902 * When natively debugging programs on PowerPC BookE processors running
3903 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
3904 watchpoints, which specify a mask in addition to an address to watch.
3905 The mask specifies that some bits of an address (the bits which are
3906 reset in the mask) should be ignored when matching the address accessed
3907 by the inferior against the watchpoint address. See the "PowerPC Embedded"
3908 section in the user manual for more details.
3910 * The new option --once causes GDBserver to stop listening for connections once
3911 the first connection is made. The listening port used by GDBserver will
3912 become available after that.
3914 * New commands "info macros" and "alias" have been added.
3916 * New function parameters suffix @entry specifies value of function parameter
3917 at the time the function got called. Entry values are available only since
3923 "!" is now an alias of the "shell" command.
3924 Note that no space is needed between "!" and SHELL COMMAND.
3928 watch EXPRESSION mask MASK_VALUE
3929 The watch command now supports the mask argument which allows creation
3930 of masked watchpoints, if the current architecture supports this feature.
3932 info auto-load-scripts [REGEXP]
3933 This command was formerly named "maintenance print section-scripts".
3934 It is now generally useful and is no longer a maintenance-only command.
3936 info macro [-all] [--] MACRO
3937 The info macro command has new options `-all' and `--'. The first for
3938 printing all definitions of a macro. The second for explicitly specifying
3939 the end of arguments and the beginning of the macro name in case the macro
3940 name starts with a hyphen.
3942 collect[/s] EXPRESSIONS
3943 The tracepoint collect command now takes an optional modifier "/s"
3944 that directs it to dereference pointer-to-character types and
3945 collect the bytes of memory up to a zero byte. The behavior is
3946 similar to what you see when you use the regular print command on a
3947 string. An optional integer following the "/s" sets a bound on the
3948 number of bytes that will be collected.
3951 The trace start command now interprets any supplied arguments as a
3952 note to be recorded with the trace run, with an effect similar to
3953 setting the variable trace-notes.
3956 The trace stop command now interprets any arguments as a note to be
3957 mentioned along with the tstatus report that the trace was stopped
3958 with a command. The effect is similar to setting the variable
3961 * Tracepoints can now be enabled and disabled at any time after a trace
3962 experiment has been started using the standard "enable" and "disable"
3963 commands. It is now possible to start a trace experiment with no enabled
3964 tracepoints; GDB will display a warning, but will allow the experiment to
3965 begin, assuming that tracepoints will be enabled as needed while the trace
3968 * Fast tracepoints on 32-bit x86-architectures can now be placed at
3969 locations with 4-byte instructions, when they were previously
3970 limited to locations with instructions of 5 bytes or longer.
3974 set debug dwarf2-read
3975 show debug dwarf2-read
3976 Turns on or off display of debugging messages related to reading
3977 DWARF debug info. The default is off.
3979 set debug symtab-create
3980 show debug symtab-create
3981 Turns on or off display of debugging messages related to symbol table
3982 creation. The default is off.
3985 show extended-prompt
3986 Set the GDB prompt, and allow escape sequences to be inserted to
3987 display miscellaneous information (see 'help set extended-prompt'
3988 for the list of sequences). This prompt (and any information
3989 accessed through the escape sequences) is updated every time the
3990 prompt is displayed.
3992 set print entry-values (both|compact|default|if-needed|no|only|preferred)
3993 show print entry-values
3994 Set printing of frame argument values at function entry. In some cases
3995 GDB can determine the value of function argument which was passed by the
3996 function caller, even if the value was modified inside the called function.
3998 set debug entry-values
3999 show debug entry-values
4000 Control display of debugging info for determining frame argument values at
4001 function entry and virtual tail call frames.
4003 set basenames-may-differ
4004 show basenames-may-differ
4005 Set whether a source file may have multiple base names.
4006 (A "base name" is the name of a file with the directory part removed.
4007 Example: The base name of "/home/user/hello.c" is "hello.c".)
4008 If set, GDB will canonicalize file names (e.g., expand symlinks)
4009 before comparing them. Canonicalization is an expensive operation,
4010 but it allows the same file be known by more than one base name.
4011 If not set (the default), all source files are assumed to have just
4012 one base name, and gdb will do file name comparisons more efficiently.
4018 Set a user name and notes for the current and any future trace runs.
4019 This is useful for long-running and/or disconnected traces, to
4020 inform others (or yourself) as to who is running the trace, supply
4021 contact information, or otherwise explain what is going on.
4023 set trace-stop-notes
4024 show trace-stop-notes
4025 Set a note attached to the trace run, that is displayed when the
4026 trace has been stopped by a tstop command. This is useful for
4027 instance as an explanation, if you are stopping a trace run that was
4028 started by someone else.
4030 * New remote packets
4034 Dynamically enable a tracepoint in a started trace experiment.
4038 Dynamically disable a tracepoint in a started trace experiment.
4042 Set the user and notes of the trace run.
4046 Query the current status of a tracepoint.
4050 Query the minimum length of instruction at which a fast tracepoint may
4053 * Dcache size (number of lines) and line-size are now runtime-configurable
4054 via "set dcache line" and "set dcache line-size" commands.
4058 Texas Instruments TMS320C6x tic6x-*-*
4062 Renesas RL78 rl78-*-elf
4064 *** Changes in GDB 7.3.1
4066 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4068 *** Changes in GDB 7.3
4070 * GDB has a new command: "thread find [REGEXP]".
4071 It finds the thread id whose name, target id, or thread extra info
4072 matches the given regular expression.
4074 * The "catch syscall" command now works on mips*-linux* targets.
4076 * The -data-disassemble MI command now supports modes 2 and 3 for
4077 dumping the instruction opcodes.
4079 * New command line options
4081 -data-directory DIR Specify DIR as the "data-directory".
4082 This is mostly for testing purposes.
4084 * The "maint set python auto-load on|off" command has been renamed to
4085 "set auto-load-scripts on|off".
4087 * GDB has a new command: "set directories".
4088 It is like the "dir" command except that it replaces the
4089 source path list instead of augmenting it.
4091 * GDB now understands thread names.
4093 On GNU/Linux, "info threads" will display the thread name as set by
4094 prctl or pthread_setname_np.
4096 There is also a new command, "thread name", which can be used to
4097 assign a name internally for GDB to display.
4100 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4101 has been integrated into GDB.
4105 ** The function gdb.Write now accepts an optional keyword 'stream'.
4106 This keyword, when provided, will direct the output to either
4107 stdout, stderr, or GDB's logging output.
4109 ** Parameters can now be be sub-classed in Python, and in particular
4110 you may implement the get_set_doc and get_show_doc functions.
4111 This improves how Parameter set/show documentation is processed
4112 and allows for more dynamic content.
4114 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4115 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4116 have an is_valid method.
4118 ** Breakpoints can now be sub-classed in Python, and in particular
4119 you may implement a 'stop' function that is executed each time
4120 the inferior reaches that breakpoint.
4122 ** New function gdb.lookup_global_symbol looks up a global symbol.
4124 ** GDB values in Python are now callable if the value represents a
4125 function. For example, if 'some_value' represents a function that
4126 takes two integer parameters and returns a value, you can call
4127 that function like so:
4129 result = some_value (10,20)
4131 ** Module gdb.types has been added.
4132 It contains a collection of utilities for working with gdb.Types objects:
4133 get_basic_type, has_field, make_enum_dict.
4135 ** Module gdb.printing has been added.
4136 It contains utilities for writing and registering pretty-printers.
4137 New classes: PrettyPrinter, SubPrettyPrinter,
4138 RegexpCollectionPrettyPrinter.
4139 New function: register_pretty_printer.
4141 ** New commands "info pretty-printers", "enable pretty-printer" and
4142 "disable pretty-printer" have been added.
4144 ** gdb.parameter("directories") is now available.
4146 ** New function gdb.newest_frame returns the newest frame in the
4149 ** The gdb.InferiorThread class has a new "name" attribute. This
4150 holds the thread's name.
4152 ** Python Support for Inferior events.
4153 Python scripts can add observers to be notified of events
4154 occurring in the process being debugged.
4155 The following events are currently supported:
4156 - gdb.events.cont Continue event.
4157 - gdb.events.exited Inferior exited event.
4158 - gdb.events.stop Signal received, and Breakpoint hit events.
4162 ** GDB now puts template parameters in scope when debugging in an
4163 instantiation. For example, if you have:
4165 template<int X> int func (void) { return X; }
4167 then if you step into func<5>, "print X" will show "5". This
4168 feature requires proper debuginfo support from the compiler; it
4169 was added to GCC 4.5.
4171 ** The motion commands "next", "finish", "until", and "advance" now
4172 work better when exceptions are thrown. In particular, GDB will
4173 no longer lose control of the inferior; instead, the GDB will
4174 stop the inferior at the point at which the exception is caught.
4175 This functionality requires a change in the exception handling
4176 code that was introduced in GCC 4.5.
4178 * GDB now follows GCC's rules on accessing volatile objects when
4179 reading or writing target state during expression evaluation.
4180 One notable difference to prior behavior is that "print x = 0"
4181 no longer generates a read of x; the value of the assignment is
4182 now always taken directly from the value being assigned.
4184 * GDB now has some support for using labels in the program's source in
4185 linespecs. For instance, you can use "advance label" to continue
4186 execution to a label.
4188 * GDB now has support for reading and writing a new .gdb_index
4189 section. This section holds a fast index of DWARF debugging
4190 information and can be used to greatly speed up GDB startup and
4191 operation. See the documentation for `save gdb-index' for details.
4193 * The "watch" command now accepts an optional "-location" argument.
4194 When used, this causes GDB to watch the memory referred to by the
4195 expression. Such a watchpoint is never deleted due to it going out
4198 * GDB now supports thread debugging of core dumps on GNU/Linux.
4200 GDB now activates thread debugging using the libthread_db library
4201 when debugging GNU/Linux core dumps, similarly to when debugging
4202 live processes. As a result, when debugging a core dump file, GDB
4203 is now able to display pthread_t ids of threads. For example, "info
4204 threads" shows the same output as when debugging the process when it
4205 was live. In earlier releases, you'd see something like this:
4208 * 1 LWP 6780 main () at main.c:10
4210 While now you see this:
4213 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4215 It is also now possible to inspect TLS variables when debugging core
4218 When debugging a core dump generated on a machine other than the one
4219 used to run GDB, you may need to point GDB at the correct
4220 libthread_db library with the "set libthread-db-search-path"
4221 command. See the user manual for more details on this command.
4223 * When natively debugging programs on PowerPC BookE processors running
4224 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4225 which stop execution of the inferior whenever it executes an instruction
4226 at any address within the specified range. See the "PowerPC Embedded"
4227 section in the user manual for more details.
4229 * New features in the GDB remote stub, GDBserver
4231 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4232 and i686 LynxOS (version 5.x).
4234 ** GDBserver is now supported on Blackfin Linux.
4236 * New native configurations
4238 ia64 HP-UX ia64-*-hpux*
4242 Analog Devices, Inc. Blackfin Processor bfin-*
4244 * Ada task switching is now supported on sparc-elf targets when
4245 debugging a program using the Ravenscar Profile. For more information,
4246 see the "Tasking Support when using the Ravenscar Profile" section
4247 in the GDB user manual.
4249 * Guile support was removed.
4251 * New features in the GNU simulator
4253 ** The --map-info flag lists all known core mappings.
4255 ** CFI flashes may be simulated via the "cfi" device.
4257 *** Changes in GDB 7.2
4259 * Shared library support for remote targets by default
4261 When GDB is configured for a generic, non-OS specific target, like
4262 for example, --target=arm-eabi or one of the many *-*-elf targets,
4263 GDB now queries remote stubs for loaded shared libraries using the
4264 `qXfer:libraries:read' packet. Previously, shared library support
4265 was always disabled for such configurations.
4269 ** Argument Dependent Lookup (ADL)
4271 In C++ ADL lookup directs function search to the namespaces of its
4272 arguments even if the namespace has not been imported.
4282 Here the compiler will search for `foo' in the namespace of 'b'
4283 and find A::foo. GDB now supports this. This construct is commonly
4284 used in the Standard Template Library for operators.
4286 ** Improved User Defined Operator Support
4288 In addition to member operators, GDB now supports lookup of operators
4289 defined in a namespace and imported with a `using' directive, operators
4290 defined in the global scope, operators imported implicitly from an
4291 anonymous namespace, and the ADL operators mentioned in the previous
4293 GDB now also supports proper overload resolution for all the previously
4294 mentioned flavors of operators.
4296 ** static const class members
4298 Printing of static const class members that are initialized in the
4299 class definition has been fixed.
4301 * Windows Thread Information Block access.
4303 On Windows targets, GDB now supports displaying the Windows Thread
4304 Information Block (TIB) structure. This structure is visible either
4305 by using the new command `info w32 thread-information-block' or, by
4306 dereferencing the new convenience variable named `$_tlb', a
4307 thread-specific pointer to the TIB. This feature is also supported
4308 when remote debugging using GDBserver.
4310 * Static tracepoints
4312 Static tracepoints are calls in the user program into a tracing
4313 library. One such library is a port of the LTTng kernel tracer to
4314 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4315 When debugging with GDBserver, GDB now supports combining the GDB
4316 tracepoint machinery with such libraries. For example: the user can
4317 use GDB to probe a static tracepoint marker (a call from the user
4318 program into the tracing library) with the new "strace" command (see
4319 "New commands" below). This creates a "static tracepoint" in the
4320 breakpoint list, that can be manipulated with the same feature set
4321 as fast and regular tracepoints. E.g., collect registers, local and
4322 global variables, collect trace state variables, and define
4323 tracepoint conditions. In addition, the user can collect extra
4324 static tracepoint marker specific data, by collecting the new
4325 $_sdata internal variable. When analyzing the trace buffer, you can
4326 inspect $_sdata like any other variable available to GDB. For more
4327 information, see the "Tracepoints" chapter in GDB user manual. New
4328 remote packets have been defined to support static tracepoints, see
4329 the "New remote packets" section below.
4331 * Better reconstruction of tracepoints after disconnected tracing
4333 GDB will attempt to download the original source form of tracepoint
4334 definitions when starting a trace run, and then will upload these
4335 upon reconnection to the target, resulting in a more accurate
4336 reconstruction of the tracepoints that are in use on the target.
4340 You can now exercise direct control over the ways that GDB can
4341 affect your program. For instance, you can disallow the setting of
4342 breakpoints, so that the program can run continuously (assuming
4343 non-stop mode). In addition, the "observer" variable is available
4344 to switch all of the different controls; in observer mode, GDB
4345 cannot affect the target's behavior at all, which is useful for
4346 tasks like diagnosing live systems in the field.
4348 * The new convenience variable $_thread holds the number of the
4351 * New remote packets
4355 Return the address of the Windows Thread Information Block of a given thread.
4359 In response to several of the tracepoint packets, the target may now
4360 also respond with a number of intermediate `qRelocInsn' request
4361 packets before the final result packet, to have GDB handle
4362 relocating an instruction to execute at a different address. This
4363 is particularly useful for stubs that support fast tracepoints. GDB
4364 reports support for this feature in the qSupported packet.
4368 List static tracepoint markers in the target program.
4372 List static tracepoint markers at a given address in the target
4375 qXfer:statictrace:read
4377 Read the static trace data collected (by a `collect $_sdata'
4378 tracepoint action). The remote stub reports support for this packet
4379 to gdb's qSupported query.
4383 Send the current settings of GDB's permission flags.
4387 Send part of the source (textual) form of a tracepoint definition,
4388 which includes location, conditional, and action list.
4390 * The source command now accepts a -s option to force searching for the
4391 script in the source search path even if the script name specifies
4394 * New features in the GDB remote stub, GDBserver
4396 - GDBserver now support tracepoints (including fast tracepoints, and
4397 static tracepoints). The feature is currently supported by the
4398 i386-linux and amd64-linux builds. See the "Tracepoints support
4399 in gdbserver" section in the manual for more information.
4401 GDBserver JIT compiles the tracepoint's conditional agent
4402 expression bytecode into native code whenever possible for low
4403 overhead dynamic tracepoints conditionals. For such tracepoints,
4404 an expression that examines program state is evaluated when the
4405 tracepoint is reached, in order to determine whether to capture
4406 trace data. If the condition is simple and false, processing the
4407 tracepoint finishes very quickly and no data is gathered.
4409 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4410 for static tracepoints support.
4412 - GDBserver now supports x86_64 Windows 64-bit debugging.
4414 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4415 it understands register description.
4417 * The --batch flag now disables pagination and queries.
4419 * X86 general purpose registers
4421 GDB now supports reading/writing byte, word and double-word x86
4422 general purpose registers directly. This means you can use, say,
4423 $ah or $ax to refer, respectively, to the byte register AH and
4424 16-bit word register AX that are actually portions of the 32-bit
4425 register EAX or 64-bit register RAX.
4427 * The `commands' command now accepts a range of breakpoints to modify.
4428 A plain `commands' following a command that creates multiple
4429 breakpoints affects all the breakpoints set by that command. This
4430 applies to breakpoints set by `rbreak', and also applies when a
4431 single `break' command creates multiple breakpoints (e.g.,
4432 breakpoints on overloaded c++ functions).
4434 * The `rbreak' command now accepts a filename specification as part of
4435 its argument, limiting the functions selected by the regex to those
4436 in the specified file.
4438 * Support for remote debugging Windows and SymbianOS shared libraries
4439 from Unix hosts has been improved. Non Windows GDB builds now can
4440 understand target reported file names that follow MS-DOS based file
4441 system semantics, such as file names that include drive letters and
4442 use the backslash character as directory separator. This makes it
4443 possible to transparently use the "set sysroot" and "set
4444 solib-search-path" on Unix hosts to point as host copies of the
4445 target's shared libraries. See the new command "set
4446 target-file-system-kind" described below, and the "Commands to
4447 specify files" section in the user manual for more information.
4451 eval template, expressions...
4452 Convert the values of one or more expressions under the control
4453 of the string template to a command line, and call it.
4455 set target-file-system-kind unix|dos-based|auto
4456 show target-file-system-kind
4457 Set or show the assumed file system kind for target reported file
4460 save breakpoints <filename>
4461 Save all current breakpoint definitions to a file suitable for use
4462 in a later debugging session. To read the saved breakpoint
4463 definitions, use the `source' command.
4465 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4468 info static-tracepoint-markers
4469 Display information about static tracepoint markers in the target.
4471 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4472 Define a static tracepoint by probing a marker at the given
4473 function, line, address, or marker ID.
4477 Enable and disable observer mode.
4479 set may-write-registers on|off
4480 set may-write-memory on|off
4481 set may-insert-breakpoints on|off
4482 set may-insert-tracepoints on|off
4483 set may-insert-fast-tracepoints on|off
4484 set may-interrupt on|off
4485 Set individual permissions for GDB effects on the target. Note that
4486 some of these settings can have undesirable or surprising
4487 consequences, particularly when changed in the middle of a session.
4488 For instance, disabling the writing of memory can prevent
4489 breakpoints from being inserted, cause single-stepping to fail, or
4490 even crash your program, if you disable after breakpoints have been
4491 inserted. However, GDB should not crash.
4493 set record memory-query on|off
4494 show record memory-query
4495 Control whether to stop the inferior if memory changes caused
4496 by an instruction cannot be recorded.
4501 The disassemble command now supports "start,+length" form of two arguments.
4505 ** GDB now provides a new directory location, called the python directory,
4506 where Python scripts written for GDB can be installed. The location
4507 of that directory is <data-directory>/python, where <data-directory>
4508 is the GDB data directory. For more details, see section `Scripting
4509 GDB using Python' in the manual.
4511 ** The GDB Python API now has access to breakpoints, symbols, symbol
4512 tables, program spaces, inferiors, threads and frame's code blocks.
4513 Additionally, GDB Parameters can now be created from the API, and
4514 manipulated via set/show in the CLI.
4516 ** New functions gdb.target_charset, gdb.target_wide_charset,
4517 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4519 ** New exception gdb.GdbError.
4521 ** Pretty-printers are now also looked up in the current program space.
4523 ** Pretty-printers can now be individually enabled and disabled.
4525 ** GDB now looks for names of Python scripts to auto-load in a
4526 special section named `.debug_gdb_scripts', in addition to looking
4527 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4529 * Tracepoint actions were unified with breakpoint commands. In particular,
4530 there are no longer differences in "info break" output for breakpoints and
4531 tracepoints and the "commands" command can be used for both tracepoints and
4532 regular breakpoints.
4536 ARM Symbian arm*-*-symbianelf*
4538 * D language support.
4539 GDB now supports debugging programs written in the D programming
4542 * GDB now supports the extended ptrace interface for PowerPC which is
4543 available since Linux kernel version 2.6.34. This automatically enables
4544 any hardware breakpoints and additional hardware watchpoints available in
4545 the processor. The old ptrace interface exposes just one hardware
4546 watchpoint and no hardware breakpoints.
4548 * GDB is now able to use the Data Value Compare (DVC) register available on
4549 embedded PowerPC processors to implement in hardware simple watchpoint
4550 conditions of the form:
4552 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4554 This works in native GDB running on Linux kernels with the extended ptrace
4555 interface mentioned above.
4557 *** Changes in GDB 7.1
4561 ** Namespace Support
4563 GDB now supports importing of namespaces in C++. This enables the
4564 user to inspect variables from imported namespaces. Support for
4565 namepace aliasing has also been added. So, if a namespace is
4566 aliased in the current scope (e.g. namepace C=A; ) the user can
4567 print variables using the alias (e.g. (gdb) print C::x).
4571 All known bugs relating to the printing of virtual base class were
4572 fixed. It is now possible to call overloaded static methods using a
4577 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4578 and reinterpret_cast<> are now handled by the C++ expression parser.
4582 Xilinx MicroBlaze microblaze-*-*
4587 Xilinx MicroBlaze microblaze
4590 * Multi-program debugging.
4592 GDB now has support for multi-program (a.k.a. multi-executable or
4593 multi-exec) debugging. This allows for debugging multiple inferiors
4594 simultaneously each running a different program under the same GDB
4595 session. See "Debugging Multiple Inferiors and Programs" in the
4596 manual for more information. This implied some user visible changes
4597 in the multi-inferior support. For example, "info inferiors" now
4598 lists inferiors that are not running yet or that have exited
4599 already. See also "New commands" and "New options" below.
4601 * New tracing features
4603 GDB's tracepoint facility now includes several new features:
4605 ** Trace state variables
4607 GDB tracepoints now include support for trace state variables, which
4608 are variables managed by the target agent during a tracing
4609 experiment. They are useful for tracepoints that trigger each
4610 other, so for instance one tracepoint can count hits in a variable,
4611 and then a second tracepoint has a condition that is true when the
4612 count reaches a particular value. Trace state variables share the
4613 $-syntax of GDB convenience variables, and can appear in both
4614 tracepoint actions and condition expressions. Use the "tvariable"
4615 command to create, and "info tvariables" to view; see "Trace State
4616 Variables" in the manual for more detail.
4620 GDB now includes an option for defining fast tracepoints, which
4621 targets may implement more efficiently, such as by installing a jump
4622 into the target agent rather than a trap instruction. The resulting
4623 speedup can be by two orders of magnitude or more, although the
4624 tradeoff is that some program locations on some target architectures
4625 might not allow fast tracepoint installation, for instance if the
4626 instruction to be replaced is shorter than the jump. To request a
4627 fast tracepoint, use the "ftrace" command, with syntax identical to
4628 the regular trace command.
4630 ** Disconnected tracing
4632 It is now possible to detach GDB from the target while it is running
4633 a trace experiment, then reconnect later to see how the experiment
4634 is going. In addition, a new variable disconnected-tracing lets you
4635 tell the target agent whether to continue running a trace if the
4636 connection is lost unexpectedly.
4640 GDB now has the ability to save the trace buffer into a file, and
4641 then use that file as a target, similarly to you can do with
4642 corefiles. You can select trace frames, print data that was
4643 collected in them, and use tstatus to display the state of the
4644 tracing run at the moment that it was saved. To create a trace
4645 file, use "tsave <filename>", and to use it, do "target tfile
4648 ** Circular trace buffer
4650 You can ask the target agent to handle the trace buffer as a
4651 circular buffer, discarding the oldest trace frames to make room for
4652 newer ones, by setting circular-trace-buffer to on. This feature may
4653 not be available for all target agents.
4658 The disassemble command, when invoked with two arguments, now requires
4659 the arguments to be comma-separated.
4662 The info variables command now displays variable definitions. Files
4663 which only declare a variable are not shown.
4666 The source command is now capable of sourcing Python scripts.
4667 This feature is dependent on the debugger being build with Python
4670 Related to this enhancement is also the introduction of a new command
4671 "set script-extension" (see below).
4673 * New commands (for set/show, see "New options" below)
4675 record save [<FILENAME>]
4676 Save a file (in core file format) containing the process record
4677 execution log for replay debugging at a later time.
4679 record restore <FILENAME>
4680 Restore the process record execution log that was saved at an
4681 earlier time, for replay debugging.
4683 add-inferior [-copies <N>] [-exec <FILENAME>]
4686 clone-inferior [-copies <N>] [ID]
4687 Make a new inferior ready to execute the same program another
4688 inferior has loaded.
4693 maint info program-spaces
4694 List the program spaces loaded into GDB.
4696 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4697 show remote interrupt-sequence
4698 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4699 as the sequence to the remote target in order to interrupt the execution.
4700 Ctrl-C is a default. Some system prefers BREAK which is high level of
4701 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4702 Magic SysRq g. It is BREAK signal and character 'g'.
4704 set remote interrupt-on-connect [on | off]
4705 show remote interrupt-on-connect
4706 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4707 remote target when gdb connects to it. This is needed when you debug
4710 set remotebreak [on | off]
4712 Deprecated. Use "set/show remote interrupt-sequence" instead.
4714 tvariable $NAME [ = EXP ]
4715 Create or modify a trace state variable.
4718 List trace state variables and their values.
4720 delete tvariable $NAME ...
4721 Delete one or more trace state variables.
4724 Evaluate the given expressions without collecting anything into the
4725 trace buffer. (Valid in tracepoint actions only.)
4727 ftrace FN / FILE:LINE / *ADDR
4728 Define a fast tracepoint at the given function, line, or address.
4730 * New expression syntax
4732 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4733 GDB now parses 0b101010 identically with 42.
4737 set follow-exec-mode new|same
4738 show follow-exec-mode
4739 Control whether GDB reuses the same inferior across an exec call or
4740 creates a new one. This is useful to be able to restart the old
4741 executable after the inferior having done an exec call.
4743 set default-collect EXPR, ...
4744 show default-collect
4745 Define a list of expressions to be collected at each tracepoint.
4746 This is a useful way to ensure essential items are not overlooked,
4747 such as registers or a critical global variable.
4749 set disconnected-tracing
4750 show disconnected-tracing
4751 If set to 1, the target is instructed to continue tracing if it
4752 loses its connection to GDB. If 0, the target is to stop tracing
4755 set circular-trace-buffer
4756 show circular-trace-buffer
4757 If set to on, the target is instructed to use a circular trace buffer
4758 and discard the oldest trace frames instead of stopping the trace due
4759 to a full trace buffer. If set to off, the trace stops when the buffer
4760 fills up. Some targets may not support this.
4762 set script-extension off|soft|strict
4763 show script-extension
4764 If set to "off", the debugger does not perform any script language
4765 recognition, and all sourced files are assumed to be GDB scripts.
4766 If set to "soft" (the default), files are sourced according to
4767 filename extension, falling back to GDB scripts if the first
4769 If set to "strict", files are sourced according to filename extension.
4771 set ada trust-PAD-over-XVS on|off
4772 show ada trust-PAD-over-XVS
4773 If off, activate a workaround against a bug in the debugging information
4774 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4775 the GCC sources for more information about the GNAT encoding and
4776 PAD types in particular). It is always safe to set this option to
4777 off, but this introduces a slight performance penalty. The default
4780 * Python API Improvements
4782 ** GDB provides the new class gdb.LazyString. This is useful in
4783 some pretty-printing cases. The new method gdb.Value.lazy_string
4784 provides a simple way to create objects of this type.
4786 ** The fields returned by gdb.Type.fields now have an
4787 `is_base_class' attribute.
4789 ** The new method gdb.Type.range returns the range of an array type.
4791 ** The new method gdb.parse_and_eval can be used to parse and
4792 evaluate an expression.
4794 * New remote packets
4797 Define a trace state variable.
4800 Get the current value of a trace state variable.
4803 Set desired tracing behavior upon disconnection.
4806 Set the trace buffer to be linear or circular.
4809 Get data about the tracepoints currently in use.
4813 Process record now works correctly with hardware watchpoints.
4815 Multiple bug fixes have been made to the mips-irix port, making it
4816 much more reliable. In particular:
4817 - Debugging threaded applications is now possible again. Previously,
4818 GDB would hang while starting the program, or while waiting for
4819 the program to stop at a breakpoint.
4820 - Attaching to a running process no longer hangs.
4821 - An error occurring while loading a core file has been fixed.
4822 - Changing the value of the PC register now works again. This fixes
4823 problems observed when using the "jump" command, or when calling
4824 a function from GDB, or even when assigning a new value to $pc.
4825 - With the "finish" and "return" commands, the return value for functions
4826 returning a small array is now correctly printed.
4827 - It is now possible to break on shared library code which gets executed
4828 during a shared library init phase (code executed while executing
4829 their .init section). Previously, the breakpoint would have no effect.
4830 - GDB is now able to backtrace through the signal handler for
4831 non-threaded programs.
4833 PIE (Position Independent Executable) programs debugging is now supported.
4834 This includes debugging execution of PIC (Position Independent Code) shared
4835 libraries although for that, it should be possible to run such libraries as an
4838 *** Changes in GDB 7.0
4840 * GDB now has an interface for JIT compilation. Applications that
4841 dynamically generate code can create symbol files in memory and register
4842 them with GDB. For users, the feature should work transparently, and
4843 for JIT developers, the interface is documented in the GDB manual in the
4844 "JIT Compilation Interface" chapter.
4846 * Tracepoints may now be conditional. The syntax is as for
4847 breakpoints; either an "if" clause appended to the "trace" command,
4848 or the "condition" command is available. GDB sends the condition to
4849 the target for evaluation using the same bytecode format as is used
4850 for tracepoint actions.
4852 * The disassemble command now supports: an optional /r modifier, print the
4853 raw instructions in hex as well as in symbolic form, and an optional /m
4854 modifier to print mixed source+assembly.
4856 * Process record and replay
4858 In a architecture environment that supports ``process record and
4859 replay'', ``process record and replay'' target can record a log of
4860 the process execution, and replay it with both forward and reverse
4863 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
4864 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
4865 set execution-direction {forward|reverse}, for targets that support
4868 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
4869 feature is available with a native GDB running on kernel version
4872 * GDB now has support for multi-byte and wide character sets on the
4873 target. Strings whose character type is wchar_t, char16_t, or
4874 char32_t are now correctly printed. GDB supports wide- and unicode-
4875 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
4876 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
4877 `printf'. This feature requires iconv to work properly; if your
4878 system does not have a working iconv, GDB can use GNU libiconv. See
4879 the installation instructions for more information.
4881 * GDB now supports automatic retrieval of shared library files from
4882 remote targets. To use this feature, specify a system root that begins
4883 with the `remote:' prefix, either via the `set sysroot' command or via
4884 the `--with-sysroot' configure-time option.
4886 * "info sharedlibrary" now takes an optional regex of libraries to show,
4887 and it now reports if a shared library has no debugging information.
4889 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
4890 now complete on file names.
4892 * When completing in expressions, gdb will attempt to limit
4893 completions to allowable structure or union fields, where appropriate.
4894 For instance, consider:
4896 # struct example { int f1; double f2; };
4897 # struct example variable;
4900 If the user types TAB at the end of this command line, the available
4901 completions will be "f1" and "f2".
4903 * Inlined functions are now supported. They show up in backtraces, and
4904 the "step", "next", and "finish" commands handle them automatically.
4906 * GDB now supports the token-splicing (##) and stringification (#)
4907 operators when expanding macros. It also supports variable-arity
4910 * GDB now supports inspecting extra signal information, exported by
4911 the new $_siginfo convenience variable. The feature is currently
4912 implemented on linux ARM, i386 and amd64.
4914 * GDB can now display the VFP floating point registers and NEON vector
4915 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
4916 can provide these registers (requires Linux 2.6.30 or later). Remote
4917 and simulator targets may also provide them.
4919 * New remote packets
4922 Search memory for a sequence of bytes.
4925 Turn off `+'/`-' protocol acknowledgments to permit more efficient
4926 operation over reliable transport links. Use of this packet is
4927 controlled by the `set remote noack-packet' command.
4930 Kill the process with the specified process ID. Use this in preference
4931 to `k' when multiprocess protocol extensions are supported.
4934 Obtains additional operating system information
4938 Read or write additional signal information.
4940 * Removed remote protocol undocumented extension
4942 An undocumented extension to the remote protocol's `S' stop reply
4943 packet that permitted the stub to pass a process id was removed.
4944 Remote servers should use the `T' stop reply packet instead.
4946 * GDB now supports multiple function calling conventions according to the
4947 DWARF-2 DW_AT_calling_convention function attribute.
4949 * The SH target utilizes the aforementioned change to distinguish between gcc
4950 and Renesas calling convention. It also adds the new CLI commands
4951 `set/show sh calling-convention'.
4953 * GDB can now read compressed debug sections, as produced by GNU gold
4954 with the --compress-debug-sections=zlib flag.
4956 * 64-bit core files are now supported on AIX.
4958 * Thread switching is now supported on Tru64.
4960 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
4961 which will be allocated using malloc later in program execution.
4963 * The qXfer:libraries:read remote protocol packet now allows passing a
4964 list of section offsets.
4966 * On GNU/Linux, GDB can now attach to stopped processes. Several race
4967 conditions handling signals delivered during attach or thread creation
4968 have also been fixed.
4970 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
4971 From the user's standpoint, all unqualified instances of True and False
4972 are treated as the standard definitions, regardless of context.
4974 * GDB now parses C++ symbol and type names more flexibly. For
4977 template<typename T> class C { };
4980 GDB will now correctly handle all of:
4982 ptype C<char const *>
4983 ptype C<char const*>
4984 ptype C<const char *>
4985 ptype C<const char*>
4987 * New features in the GDB remote stub, gdbserver
4989 - The "--wrapper" command-line argument tells gdbserver to use a
4990 wrapper program to launch programs for debugging.
4992 - On PowerPC and S/390 targets, it is now possible to use a single
4993 gdbserver executable to debug both 32-bit and 64-bit programs.
4994 (This requires gdbserver itself to be built as a 64-bit executable.)
4996 - gdbserver uses the new noack protocol mode for TCP connections to
4997 reduce communications latency, if also supported and enabled in GDB.
4999 - Support for the sparc64-linux-gnu target is now included in
5002 - The amd64-linux build of gdbserver now supports debugging both
5003 32-bit and 64-bit programs.
5005 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5006 now support hardware watchpoints, and will use them automatically
5011 GDB now has support for scripting using Python. Whether this is
5012 available is determined at configure time.
5014 New GDB commands can now be written in Python.
5016 * Ada tasking support
5018 Ada tasks can now be inspected in GDB. The following commands have
5022 Print the list of Ada tasks.
5024 Print detailed information about task number N.
5026 Print the task number of the current task.
5028 Switch the context of debugging to task number N.
5030 * Support for user-defined prefixed commands. The "define" command can
5031 add new commands to existing prefixes, e.g. "target".
5033 * Multi-inferior, multi-process debugging.
5035 GDB now has generalized support for multi-inferior debugging. See
5036 "Debugging Multiple Inferiors" in the manual for more information.
5037 Although availability still depends on target support, the command
5038 set is more uniform now. The GNU/Linux specific multi-forks support
5039 has been migrated to this new framework. This implied some user
5040 visible changes; see "New commands" and also "Removed commands"
5043 * Target descriptions can now describe the target OS ABI. See the
5044 "Target Description Format" section in the user manual for more
5047 * Target descriptions can now describe "compatible" architectures
5048 to indicate that the target can execute applications for a different
5049 architecture in addition to those for the main target architecture.
5050 See the "Target Description Format" section in the user manual for
5053 * Multi-architecture debugging.
5055 GDB now includes general supports for debugging applications on
5056 hybrid systems that use more than one single processor architecture
5057 at the same time. Each such hybrid architecture still requires
5058 specific support to be added. The only hybrid architecture supported
5059 in this version of GDB is the Cell Broadband Engine.
5061 * GDB now supports integrated debugging of Cell/B.E. applications that
5062 use both the PPU and SPU architectures. To enable support for hybrid
5063 Cell/B.E. debugging, you need to configure GDB to support both the
5064 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5065 --enable-targets configure option.
5067 * Non-stop mode debugging.
5069 For some targets, GDB now supports an optional mode of operation in
5070 which you can examine stopped threads while other threads continue
5071 to execute freely. This is referred to as non-stop mode, with the
5072 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5073 section in the user manual for more information.
5075 To be able to support remote non-stop debugging, a remote stub needs
5076 to implement the non-stop mode remote protocol extensions, as
5077 described in the "Remote Non-Stop" section of the user manual. The
5078 GDB remote stub, gdbserver, has been adjusted to support these
5079 extensions on linux targets.
5081 * New commands (for set/show, see "New options" below)
5083 catch syscall [NAME(S) | NUMBER(S)]
5084 Catch system calls. Arguments, which should be names of system
5085 calls or their numbers, mean catch only those syscalls. Without
5086 arguments, every syscall will be caught. When the inferior issues
5087 any of the specified syscalls, GDB will stop and announce the system
5088 call, both when it is called and when its call returns. This
5089 feature is currently available with a native GDB running on the
5090 Linux Kernel, under the following architectures: x86, x86_64,
5091 PowerPC and PowerPC64.
5093 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5095 Search memory for a sequence of bytes.
5097 maint set python print-stack
5098 maint show python print-stack
5099 Show a stack trace when an error is encountered in a Python script.
5102 Invoke CODE by passing it to the Python interpreter.
5107 These allow macros to be defined, undefined, and listed
5111 Show operating system information about processes.
5114 List the inferiors currently under GDB's control.
5117 Switch focus to inferior number NUM.
5120 Detach from inferior number NUM.
5123 Kill inferior number NUM.
5127 set spu stop-on-load
5128 show spu stop-on-load
5129 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5131 set spu auto-flush-cache
5132 show spu auto-flush-cache
5133 Control whether to automatically flush the software-managed cache
5134 during Cell/B.E. debugging.
5136 set sh calling-convention
5137 show sh calling-convention
5138 Control the calling convention used when calling SH target functions.
5141 show debug timestamp
5142 Control display of timestamps with GDB debugging output.
5144 set disassemble-next-line
5145 show disassemble-next-line
5146 Control display of disassembled source lines or instructions when
5149 set remote noack-packet
5150 show remote noack-packet
5151 Set/show the use of remote protocol QStartNoAckMode packet. See above
5152 under "New remote packets."
5154 set remote query-attached-packet
5155 show remote query-attached-packet
5156 Control use of remote protocol `qAttached' (query-attached) packet.
5158 set remote read-siginfo-object
5159 show remote read-siginfo-object
5160 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5163 set remote write-siginfo-object
5164 show remote write-siginfo-object
5165 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5168 set remote reverse-continue
5169 show remote reverse-continue
5170 Control use of remote protocol 'bc' (reverse-continue) packet.
5172 set remote reverse-step
5173 show remote reverse-step
5174 Control use of remote protocol 'bs' (reverse-step) packet.
5176 set displaced-stepping
5177 show displaced-stepping
5178 Control displaced stepping mode. Displaced stepping is a way to
5179 single-step over breakpoints without removing them from the debuggee.
5180 Also known as "out-of-line single-stepping".
5183 show debug displaced
5184 Control display of debugging info for displaced stepping.
5186 maint set internal-error
5187 maint show internal-error
5188 Control what GDB does when an internal error is detected.
5190 maint set internal-warning
5191 maint show internal-warning
5192 Control what GDB does when an internal warning is detected.
5197 Use a wrapper program to launch programs for debugging.
5199 set multiple-symbols (all|ask|cancel)
5200 show multiple-symbols
5201 The value of this variable can be changed to adjust the debugger behavior
5202 when an expression or a breakpoint location contains an ambiguous symbol
5203 name (an overloaded function name, for instance).
5205 set breakpoint always-inserted
5206 show breakpoint always-inserted
5207 Keep breakpoints always inserted in the target, as opposed to inserting
5208 them when resuming the target, and removing them when the target stops.
5209 This option can improve debugger performance on slow remote targets.
5211 set arm fallback-mode (arm|thumb|auto)
5212 show arm fallback-mode
5213 set arm force-mode (arm|thumb|auto)
5215 These commands control how ARM GDB determines whether instructions
5216 are ARM or Thumb. The default for both settings is auto, which uses
5217 the current CPSR value for instructions without symbols; previous
5218 versions of GDB behaved as if "set arm fallback-mode arm".
5220 set arm unwind-secure-frames
5221 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5223 This can trigger security exceptions when unwinding exception stacks.
5225 set disable-randomization
5226 show disable-randomization
5227 Standalone programs run with the virtual address space randomization enabled
5228 by default on some platforms. This option keeps the addresses stable across
5229 multiple debugging sessions.
5233 Control whether other threads are stopped or not when some thread hits
5238 Requests that asynchronous execution is enabled in the target, if available.
5239 In this case, it's possible to resume target in the background, and interact
5240 with GDB while the target is running. "show target-async" displays the
5241 current state of asynchronous execution of the target.
5243 set target-wide-charset
5244 show target-wide-charset
5245 The target-wide-charset is the name of the character set that GDB
5246 uses when printing characters whose type is wchar_t.
5248 set tcp auto-retry (on|off)
5250 set tcp connect-timeout
5251 show tcp connect-timeout
5252 These commands allow GDB to retry failed TCP connections to a remote stub
5253 with a specified timeout period; this is useful if the stub is launched
5254 in parallel with GDB but may not be ready to accept connections immediately.
5256 set libthread-db-search-path
5257 show libthread-db-search-path
5258 Control list of directories which GDB will search for appropriate
5261 set schedule-multiple (on|off)
5262 show schedule-multiple
5263 Allow GDB to resume all threads of all processes or only threads of
5264 the current process.
5268 Use more aggressive caching for accesses to the stack. This improves
5269 performance of remote debugging (particularly backtraces) without
5270 affecting correctness.
5272 set interactive-mode (on|off|auto)
5273 show interactive-mode
5274 Control whether GDB runs in interactive mode (on) or not (off).
5275 When in interactive mode, GDB waits for the user to answer all
5276 queries. Otherwise, GDB does not wait and assumes the default
5277 answer. When set to auto (the default), GDB determines which
5278 mode to use based on the stdin settings.
5283 For program forks, this is replaced by the new more generic `info
5284 inferiors' command. To list checkpoints, you can still use the
5285 `info checkpoints' command, which was an alias for the `info forks'
5289 Replaced by the new `inferior' command. To switch between
5290 checkpoints, you can still use the `restart' command, which was an
5291 alias for the `fork' command.
5294 This is removed, since some targets don't have a notion of
5295 processes. To switch between processes, you can still use the
5296 `inferior' command using GDB's own inferior number.
5299 For program forks, this is replaced by the new more generic `kill
5300 inferior' command. To delete a checkpoint, you can still use the
5301 `delete checkpoint' command, which was an alias for the `delete
5305 For program forks, this is replaced by the new more generic `detach
5306 inferior' command. To detach a checkpoint, you can still use the
5307 `detach checkpoint' command, which was an alias for the `detach
5310 * New native configurations
5312 x86/x86_64 Darwin i[34567]86-*-darwin*
5314 x86_64 MinGW x86_64-*-mingw*
5318 Lattice Mico32 lm32-*
5319 x86 DICOS i[34567]86-*-dicos*
5320 x86_64 DICOS x86_64-*-dicos*
5323 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5324 (mingw32ce) debugging.
5330 These commands were actually not implemented on any target.
5332 *** Changes in GDB 6.8
5334 * New native configurations
5336 NetBSD/hppa hppa*-*netbsd*
5337 Xtensa GNU/Linux xtensa*-*-linux*
5341 NetBSD/hppa hppa*-*-netbsd*
5342 Xtensa GNU/Linux xtensa*-*-linux*
5344 * Change in command line behavior -- corefiles vs. process ids.
5346 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5347 attaching to process NUMBER fails, GDB no longer attempts to open a
5348 core file named NUMBER. Attaching to a program using the -c option
5349 is no longer supported. Instead, use the '-p' or '--pid' options.
5351 * GDB can now be built as a native debugger for debugging Windows x86
5352 (mingw32) Portable Executable (PE) programs.
5354 * Pending breakpoints no longer change their number when their address
5357 * GDB now supports breakpoints with multiple locations,
5358 including breakpoints on C++ constructors, inside C++ templates,
5359 and in inlined functions.
5361 * GDB's ability to debug optimized code has been improved. GDB more
5362 accurately identifies function bodies and lexical blocks that occupy
5363 more than one contiguous range of addresses.
5365 * Target descriptions can now describe registers for PowerPC.
5367 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5368 registers on PowerPC targets.
5370 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5371 targets even when the libthread_db library is not available.
5373 * The GDB remote stub, gdbserver, now supports the new file transfer
5374 commands (remote put, remote get, and remote delete).
5376 * The GDB remote stub, gdbserver, now supports run and attach in
5377 extended-remote mode.
5379 * hppa*64*-*-hpux11* target broken
5380 The debugger is unable to start a program and fails with the following
5381 error: "Error trying to get information about dynamic linker".
5382 The gdb-6.7 release is also affected.
5384 * GDB now supports the --enable-targets= configure option to allow
5385 building a single GDB executable that supports multiple remote
5386 target architectures.
5388 * GDB now supports debugging C and C++ programs which use the
5389 Decimal Floating Point extension. In addition, the PowerPC target
5390 now has a set of pseudo-registers to inspect decimal float values
5391 stored in two consecutive float registers.
5393 * The -break-insert MI command can optionally create pending
5396 * Improved support for debugging Ada
5397 Many improvements to the Ada language support have been made. These
5399 - Better support for Ada2005 interface types
5400 - Improved handling of arrays and slices in general
5401 - Better support for Taft-amendment types
5402 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5404 - Improved command completion in Ada
5407 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5412 set print frame-arguments (all|scalars|none)
5413 show print frame-arguments
5414 The value of this variable can be changed to control which argument
5415 values should be printed by the debugger when displaying a frame.
5420 Transfer files to and from a remote target, and delete remote files.
5427 Transfer files to and from a remote target, and delete remote files.
5429 * New remote packets
5436 Open, close, read, write, and delete files on the remote system.
5439 Attach to an existing process on the remote system, in extended-remote
5443 Run a new process on the remote system, in extended-remote mode.
5445 *** Changes in GDB 6.7
5447 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5448 bfd, libiberty and opcodes, as revealed by static analysis donated by
5449 Coverity, Inc. (http://scan.coverity.com).
5451 * When looking up multiply-defined global symbols, GDB will now prefer the
5452 symbol definition in the current shared library if it was built using the
5453 -Bsymbolic linker option.
5455 * When the Text User Interface (TUI) is not configured, GDB will now
5456 recognize the -tui command-line option and print a message that the TUI
5459 * The GDB remote stub, gdbserver, now has lower overhead for high
5460 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5462 * GDB for MIPS targets now autodetects whether a remote target provides
5463 32-bit or 64-bit register values.
5465 * Support for C++ member pointers has been improved.
5467 * GDB now understands XML target descriptions, which specify the
5468 target's overall architecture. GDB can read a description from
5469 a local file or over the remote serial protocol.
5471 * Vectors of single-byte data use a new integer type which is not
5472 automatically displayed as character or string data.
5474 * The /s format now works with the print command. It displays
5475 arrays of single-byte integers and pointers to single-byte integers
5478 * Target descriptions can now describe target-specific registers,
5479 for architectures which have implemented the support (currently
5480 only ARM, M68K, and MIPS).
5482 * GDB and the GDB remote stub, gdbserver, now support the XScale
5485 * The GDB remote stub, gdbserver, has been updated to support
5486 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5487 has been rewritten to use the standard GDB remote protocol.
5489 * GDB can now step into C++ functions which are called through thunks.
5491 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5493 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5494 layout. It also supports a TextSeg= and DataSeg= response when only
5495 segment base addresses (rather than offsets) are available.
5497 * The /i format now outputs any trailing branch delay slot instructions
5498 immediately following the last instruction within the count specified.
5500 * The GDB remote protocol "T" stop reply packet now supports a
5501 "library" response. Combined with the new "qXfer:libraries:read"
5502 packet, this response allows GDB to debug shared libraries on targets
5503 where the operating system manages the list of loaded libraries (e.g.
5504 Windows and SymbianOS).
5506 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5507 (DLLs) on Windows and Windows CE targets.
5509 * GDB now supports a faster verification that a .debug file matches its binary
5510 according to its build-id signature, if the signature is present.
5516 Enable or disable hardware flow control (RTS/CTS) on the serial port
5517 when debugging using remote targets.
5519 set mem inaccessible-by-default
5520 show mem inaccessible-by-default
5521 If the target supplies a memory map, for instance via the remote
5522 protocol's "qXfer:memory-map:read" packet, setting this variable
5523 prevents GDB from accessing memory outside the memory map. This
5524 is useful for targets with memory mapped registers or which react
5525 badly to accesses of unmapped address space.
5527 set breakpoint auto-hw
5528 show breakpoint auto-hw
5529 If the target supplies a memory map, for instance via the remote
5530 protocol's "qXfer:memory-map:read" packet, setting this variable
5531 lets GDB use hardware breakpoints automatically for memory regions
5532 where it can not use software breakpoints. This covers both the
5533 "break" command and internal breakpoints used for other commands
5534 including "next" and "finish".
5537 catch exception unhandled
5538 Stop the program execution when Ada exceptions are raised.
5541 Stop the program execution when an Ada assertion failed.
5545 Set an alternate system root for target files. This is a more
5546 general version of "set solib-absolute-prefix", which is now
5547 an alias to "set sysroot".
5550 Provide extended SPU facility status information. This set of
5551 commands is available only when debugging the Cell/B.E. SPU
5554 * New native configurations
5556 OpenBSD/sh sh*-*openbsd*
5559 unset tdesc filename
5561 Use the specified local file as an XML target description, and do
5562 not query the target for its built-in description.
5566 OpenBSD/sh sh*-*-openbsd*
5567 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5568 Toshiba Media Processor mep-elf
5570 * New remote packets
5573 Ignore the specified signals; pass them directly to the debugged program
5574 without stopping other threads or reporting them to GDB.
5576 qXfer:features:read:
5577 Read an XML target description from the target, which describes its
5582 Read or write contents of an spufs file on the target system. These
5583 packets are available only on the Cell/B.E. SPU architecture.
5585 qXfer:libraries:read:
5586 Report the loaded shared libraries. Combined with new "T" packet
5587 response, this packet allows GDB to debug shared libraries on
5588 targets where the operating system manages the list of loaded
5589 libraries (e.g. Windows and SymbianOS).
5593 Support for these obsolete configurations has been removed.
5601 i[34567]86-*-lynxos*
5602 i[34567]86-*-netware*
5603 i[34567]86-*-sco3.2v5*
5604 i[34567]86-*-sco3.2v4*
5606 i[34567]86-*-sysv4.2*
5609 i[34567]86-*-unixware2*
5610 i[34567]86-*-unixware*
5619 * Other removed features
5626 Various m68k-only ROM monitors.
5633 Various Renesas ROM monitors and debugging interfaces for SH and
5638 Support for a Macraigor serial interface to on-chip debugging.
5639 GDB does not directly support the newer parallel or USB
5644 A debug information format. The predecessor to DWARF 2 and
5645 DWARF 3, which are still supported.
5647 Support for the HP aCC compiler on HP-UX/PA-RISC
5649 SOM-encapsulated symbolic debugging information, automatic
5650 invocation of pxdb, and the aCC custom C++ ABI. This does not
5651 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5652 with aCC can still be debugged on an assembly level.
5654 MIPS ".pdr" sections
5656 A MIPS-specific format used to describe stack frame layout
5657 in debugging information.
5661 GDB could work with an older version of Guile to debug
5662 the interpreter and Scheme programs running in it.
5664 set mips stack-arg-size
5665 set mips saved-gpreg-size
5667 Use "set mips abi" to control parameter passing for MIPS.
5669 *** Changes in GDB 6.6
5674 Cell Broadband Engine SPU spu-elf
5676 * GDB can now be configured as a cross-debugger targeting native Windows
5677 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5678 running on a Windows system over TCP/IP to debug Windows programs.
5680 * The GDB remote stub, gdbserver, has been updated to support Windows and
5681 Cygwin debugging. Both single-threaded and multi-threaded programs are
5684 * The "set trust-readonly-sections" command works again. This command was
5685 broken in GDB 6.3, 6.4, and 6.5.
5687 * The "load" command now supports writing to flash memory, if the remote
5688 stub provides the required support.
5690 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5691 longer requires symbolic debug information (e.g. DWARF-2).
5696 unset substitute-path
5697 show substitute-path
5698 Manage a list of substitution rules that GDB uses to rewrite the name
5699 of the directories where the sources are located. This can be useful
5700 for instance when the sources were moved to a different location
5701 between compilation and debugging.
5705 Print each CLI command as it is executed. Each command is prefixed with
5706 a number of `+' symbols representing the nesting depth.
5707 The source command now has a `-v' option to enable the same feature.
5711 The ARM Demon monitor support (RDP protocol, "target rdp").
5713 Kernel Object Display, an embedded debugging feature which only worked with
5714 an obsolete version of Cisco IOS.
5716 The 'set download-write-size' and 'show download-write-size' commands.
5718 * New remote packets
5721 Tell a stub about GDB client features, and request remote target features.
5722 The first feature implemented is PacketSize, which allows the target to
5723 specify the size of packets it can handle - to minimize the number of
5724 packets required and improve performance when connected to a remote
5728 Fetch an OS auxilliary vector from the remote stub. This packet is a
5729 more efficient replacement for qPart:auxv:read.
5731 qXfer:memory-map:read:
5732 Fetch a memory map from the remote stub, including information about
5733 RAM, ROM, and flash memory devices.
5738 Erase and program a flash memory device.
5740 * Removed remote packets
5743 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5744 used it, and only gdbserver implemented it.
5746 *** Changes in GDB 6.5
5750 Renesas M32C/M16C m32c-elf
5752 Morpho Technologies ms1 ms1-elf
5756 init-if-undefined Initialize a convenience variable, but
5757 only if it doesn't already have a value.
5759 The following commands are presently only implemented for native GNU/Linux:
5761 checkpoint Save a snapshot of the program state.
5763 restart <n> Return the program state to a
5764 previously saved state.
5766 info checkpoints List currently saved checkpoints.
5768 delete-checkpoint <n> Delete a previously saved checkpoint.
5770 set|show detach-on-fork Tell gdb whether to detach from a newly
5771 forked process, or to keep debugging it.
5773 info forks List forks of the user program that
5774 are available to be debugged.
5776 fork <n> Switch to debugging one of several
5777 forks of the user program that are
5778 available to be debugged.
5780 delete-fork <n> Delete a fork from the list of forks
5781 that are available to be debugged (and
5782 kill the forked process).
5784 detach-fork <n> Delete a fork from the list of forks
5785 that are available to be debugged (and
5786 allow the process to continue).
5790 Morpho Technologies ms2 ms1-elf
5792 * Improved Windows host support
5794 GDB now builds as a cross debugger hosted on i686-mingw32, including
5795 native console support, and remote communications using either
5796 network sockets or serial ports.
5798 * Improved Modula-2 language support
5800 GDB can now print most types in the Modula-2 syntax. This includes:
5801 basic types, set types, record types, enumerated types, range types,
5802 pointer types and ARRAY types. Procedure var parameters are correctly
5803 printed and hexadecimal addresses and character constants are also
5804 written in the Modula-2 syntax. Best results can be obtained by using
5805 GNU Modula-2 together with the -gdwarf-2 command line option.
5809 The ARM rdi-share module.
5811 The Netware NLM debug server.
5813 *** Changes in GDB 6.4
5815 * New native configurations
5817 OpenBSD/arm arm*-*-openbsd*
5818 OpenBSD/mips64 mips64-*-openbsd*
5822 Morpho Technologies ms1 ms1-elf
5824 * New command line options
5826 --batch-silent As for --batch, but totally silent.
5827 --return-child-result The debugger will exist with the same value
5828 the child (debugged) program exited with.
5829 --eval-command COMMAND, -ex COMMAND
5830 Execute a single GDB CLI command. This may be
5831 specified multiple times and in conjunction
5832 with the --command (-x) option.
5834 * Deprecated commands removed
5836 The following commands, that were deprecated in 2000, have been
5840 set|show arm disassembly-flavor set|show arm disassembler
5841 othernames set arm disassembler
5842 set|show remotedebug set|show debug remote
5843 set|show archdebug set|show debug arch
5844 set|show eventdebug set|show debug event
5847 * New BSD user-level threads support
5849 It is now possible to debug programs using the user-level threads
5850 library on OpenBSD and FreeBSD. Currently supported (target)
5853 FreeBSD/amd64 x86_64-*-freebsd*
5854 FreeBSD/i386 i386-*-freebsd*
5855 OpenBSD/i386 i386-*-openbsd*
5857 Note that the new kernel threads libraries introduced in FreeBSD 5.x
5858 are not yet supported.
5860 * New support for Matsushita MN10300 w/sim added
5861 (Work in progress). mn10300-elf.
5863 * REMOVED configurations and files
5865 VxWorks and the XDR protocol *-*-vxworks
5866 Motorola MCORE mcore-*-*
5867 National Semiconductor NS32000 ns32k-*-*
5869 * New "set print array-indexes" command
5871 After turning this setting "on", GDB prints the index of each element
5872 when displaying arrays. The default is "off" to preserve the previous
5875 * VAX floating point support
5877 GDB now supports the not-quite-ieee VAX F and D floating point formats.
5879 * User-defined command support
5881 In addition to using $arg0..$arg9 for argument passing, it is now possible
5882 to use $argc to determine now many arguments have been passed. See the
5883 section on user-defined commands in the user manual for more information.
5885 *** Changes in GDB 6.3:
5887 * New command line option
5889 GDB now accepts -l followed by a number to set the timeout for remote
5892 * GDB works with GCC -feliminate-dwarf2-dups
5894 GDB now supports a more compact representation of DWARF-2 debug
5895 information using DW_FORM_ref_addr references. These are produced
5896 by GCC with the option -feliminate-dwarf2-dups and also by some
5897 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
5898 to use -feliminate-dwarf2-dups.
5900 * Internationalization
5902 When supported by the host system, GDB will be built with
5903 internationalization (libintl). The task of marking up the sources is
5904 continued, we're looking forward to our first translation.
5908 Initial support for debugging programs compiled with the GNAT
5909 implementation of the Ada programming language has been integrated
5910 into GDB. In this release, support is limited to expression evaluation.
5912 * New native configurations
5914 GNU/Linux/m32r m32r-*-linux-gnu
5918 GDB's remote protocol now includes support for the 'p' packet. This
5919 packet is used to fetch individual registers from a remote inferior.
5921 * END-OF-LIFE registers[] compatibility module
5923 GDB's internal register infrastructure has been completely rewritten.
5924 The new infrastructure making possible the implementation of key new
5925 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
5928 GDB 6.3 will be the last release to include the registers[]
5929 compatibility module that allowed out-of-date configurations to
5930 continue to work. This change directly impacts the following
5940 powerpc bdm protocol
5942 Unless there is activity to revive these configurations, they will be
5943 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
5945 * OBSOLETE configurations and files
5947 Configurations that have been declared obsolete in this release have
5948 been commented out. Unless there is activity to revive these
5949 configurations, the next release of GDB will have their sources
5950 permanently REMOVED.
5959 *** Changes in GDB 6.2.1:
5961 * MIPS `break main; run' gave an heuristic-fence-post warning
5963 When attempting to run even a simple program, a warning about
5964 heuristic-fence-post being hit would be reported. This problem has
5967 * MIPS IRIX 'long double' crashed GDB
5969 When examining a long double variable, GDB would get a segmentation
5970 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
5971 IRIX long double values).
5975 A bug in the VAX stack code was causing problems with the "next"
5976 command. This problem has been fixed.
5978 *** Changes in GDB 6.2:
5980 * Fix for ``many threads''
5982 On GNU/Linux systems that use the NPTL threads library, a program
5983 rapidly creating and deleting threads would confuse GDB leading to the
5986 ptrace: No such process.
5987 thread_db_get_info: cannot get thread info: generic error
5989 This problem has been fixed.
5991 * "-async" and "-noasync" options removed.
5993 Support for the broken "-noasync" option has been removed (it caused
5996 * New ``start'' command.
5998 This command runs the program until the beginning of the main procedure.
6000 * New BSD Kernel Data Access Library (libkvm) interface
6002 Using ``target kvm'' it is now possible to debug kernel core dumps and
6003 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6004 platforms. Currently supported (native-only) configurations are:
6006 FreeBSD/amd64 x86_64-*-freebsd*
6007 FreeBSD/i386 i?86-*-freebsd*
6008 NetBSD/i386 i?86-*-netbsd*
6009 NetBSD/m68k m68*-*-netbsd*
6010 NetBSD/sparc sparc-*-netbsd*
6011 OpenBSD/amd64 x86_64-*-openbsd*
6012 OpenBSD/i386 i?86-*-openbsd*
6013 OpenBSD/m68k m68*-openbsd*
6014 OpenBSD/sparc sparc-*-openbsd*
6016 * Signal trampoline code overhauled
6018 Many generic problems with GDB's signal handling code have been fixed.
6019 These include: backtraces through non-contiguous stacks; recognition
6020 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6021 call; backtrace through a signal trampoline; step into and out of
6022 signal handlers; and single-stepping in the signal trampoline.
6024 Please note that kernel bugs are a limiting factor here. These
6025 features have been shown to work on an s390 GNU/Linux system that
6026 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6028 * Cygwin support for DWARF 2 added.
6030 * New native configurations
6032 GNU/Linux/hppa hppa*-*-linux*
6033 OpenBSD/hppa hppa*-*-openbsd*
6034 OpenBSD/m68k m68*-*-openbsd*
6035 OpenBSD/m88k m88*-*-openbsd*
6036 OpenBSD/powerpc powerpc-*-openbsd*
6037 NetBSD/vax vax-*-netbsd*
6038 OpenBSD/vax vax-*-openbsd*
6040 * END-OF-LIFE frame compatibility module
6042 GDB's internal frame infrastructure has been completely rewritten.
6043 The new infrastructure making it possible to support key new features
6044 including DWARF 2 Call Frame Information. To aid in the task of
6045 migrating old configurations to this new infrastructure, a
6046 compatibility module, that allowed old configurations to continue to
6047 work, was also included.
6049 GDB 6.2 will be the last release to include this frame compatibility
6050 module. This change directly impacts the following configurations:
6060 Unless there is activity to revive these configurations, they will be
6061 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6063 * REMOVED configurations and files
6065 Sun 3, running SunOS 3 m68*-*-sunos3*
6066 Sun 3, running SunOS 4 m68*-*-sunos4*
6067 Sun 2, running SunOS 3 m68000-*-sunos3*
6068 Sun 2, running SunOS 4 m68000-*-sunos4*
6069 Motorola 680x0 running LynxOS m68*-*-lynxos*
6070 AT&T 3b1/Unix pc m68*-att-*
6071 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6072 decstation mips-dec-* mips-little-*
6073 riscos mips-*-riscos* mips-*-sysv*
6074 sonymips mips-sony-*
6075 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6077 *** Changes in GDB 6.1.1:
6079 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6081 The TUI (Text-mode User Interface) is now built as part of a default
6082 GDB configuration. It is enabled by either selecting the TUI with the
6083 command line option "-i=tui" or by running the separate "gdbtui"
6084 program. For more information on the TUI, see the manual "Debugging
6087 * Pending breakpoint support (also included in GDB 6.1)
6089 Support has been added to allow you to specify breakpoints in shared
6090 libraries that have not yet been loaded. If a breakpoint location
6091 cannot be found, and the "breakpoint pending" option is set to auto,
6092 GDB queries you if you wish to make the breakpoint pending on a future
6093 shared-library load. If and when GDB resolves the breakpoint symbol,
6094 the pending breakpoint is removed as one or more regular breakpoints
6097 Pending breakpoints are very useful for GCJ Java debugging.
6099 * Fixed ISO-C build problems
6101 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6102 non ISO-C code that stopped them being built using a more strict ISO-C
6103 compiler (e.g., IBM's C compiler).
6105 * Fixed build problem on IRIX 5
6107 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6108 wasn't able to compile compile on an IRIX 5 system.
6110 * Added execute permission to gdb/gdbserver/configure
6112 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6113 permission. This bug would cause configure to fail on a number of
6114 systems (Solaris, IRIX). Ref: server/519.
6116 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6118 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6119 has been updated to use constant array sizes.
6121 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6123 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6124 its generated DWARF Call Frame Info. This encoding was causing GDB to
6125 panic, that panic has been fixed. Ref: gdb/1628.
6127 * Fixed a problem when examining parameters in shared library code.
6129 When examining parameters in optimized shared library code generated
6130 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6131 not available''. GDB now correctly displays the variable's value.
6133 *** Changes in GDB 6.1:
6135 * Removed --with-mmalloc
6137 Support for the mmalloc memory manager has been removed, as it
6138 conflicted with the internal gdb byte cache.
6140 * Changes in AMD64 configurations
6142 The AMD64 target now includes the %cs and %ss registers. As a result
6143 the AMD64 remote protocol has changed; this affects the floating-point
6144 and SSE registers. If you rely on those registers for your debugging,
6145 you should upgrade gdbserver on the remote side.
6147 * Revised SPARC target
6149 The SPARC target has been completely revised, incorporating the
6150 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6151 support for LynxOS and SunOS 4 has been dropped. Calling functions
6152 from within GDB on operating systems with a non-executable stack
6153 (Solaris, OpenBSD) now works.
6157 GDB has a new C++ demangler which does a better job on the mangled
6158 names generated by current versions of g++. It also runs faster, so
6159 with this and other changes gdb should now start faster on large C++
6162 * DWARF 2 Location Expressions
6164 GDB support for location expressions has been extended to support function
6165 arguments and frame bases. Older versions of GDB could crash when they
6168 * C++ nested types and namespaces
6170 GDB's support for nested types and namespaces in C++ has been
6171 improved, especially if you use the DWARF 2 debugging format. (This
6172 is the default for recent versions of GCC on most platforms.)
6173 Specifically, if you have a class "Inner" defined within a class or
6174 namespace "Outer", then GDB realizes that the class's name is
6175 "Outer::Inner", not simply "Inner". This should greatly reduce the
6176 frequency of complaints about not finding RTTI symbols. In addition,
6177 if you are stopped at inside of a function defined within a namespace,
6178 GDB modifies its name lookup accordingly.
6180 * New native configurations
6182 NetBSD/amd64 x86_64-*-netbsd*
6183 OpenBSD/amd64 x86_64-*-openbsd*
6184 OpenBSD/alpha alpha*-*-openbsd*
6185 OpenBSD/sparc sparc-*-openbsd*
6186 OpenBSD/sparc64 sparc64-*-openbsd*
6188 * New debugging protocols
6190 M32R with SDI protocol m32r-*-elf*
6192 * "set prompt-escape-char" command deleted.
6194 The command "set prompt-escape-char" has been deleted. This command,
6195 and its very obscure effect on GDB's prompt, was never documented,
6196 tested, nor mentioned in the NEWS file.
6198 * OBSOLETE configurations and files
6200 Configurations that have been declared obsolete in this release have
6201 been commented out. Unless there is activity to revive these
6202 configurations, the next release of GDB will have their sources
6203 permanently REMOVED.
6205 Sun 3, running SunOS 3 m68*-*-sunos3*
6206 Sun 3, running SunOS 4 m68*-*-sunos4*
6207 Sun 2, running SunOS 3 m68000-*-sunos3*
6208 Sun 2, running SunOS 4 m68000-*-sunos4*
6209 Motorola 680x0 running LynxOS m68*-*-lynxos*
6210 AT&T 3b1/Unix pc m68*-att-*
6211 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6212 decstation mips-dec-* mips-little-*
6213 riscos mips-*-riscos* mips-*-sysv*
6214 sonymips mips-sony-*
6215 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6217 * REMOVED configurations and files
6219 SGI Irix-4.x mips-sgi-irix4 or iris4
6220 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6221 Z8000 simulator z8k-zilog-none or z8ksim
6222 Matsushita MN10200 w/simulator mn10200-*-*
6223 H8/500 simulator h8500-hitachi-hms or h8500hms
6224 HP/PA running BSD hppa*-*-bsd*
6225 HP/PA running OSF/1 hppa*-*-osf*
6226 HP/PA Pro target hppa*-*-pro*
6227 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6228 386BSD i[3456]86-*-bsd*
6229 Sequent family i[3456]86-sequent-sysv4*
6230 i[3456]86-sequent-sysv*
6231 i[3456]86-sequent-bsd*
6232 SPARC running LynxOS sparc-*-lynxos*
6233 SPARC running SunOS 4 sparc-*-sunos4*
6234 Tsqware Sparclet sparclet-*-*
6235 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6237 *** Changes in GDB 6.0:
6241 Support for debugging the Objective-C programming language has been
6242 integrated into GDB.
6244 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6246 DWARF 2's Call Frame Information makes available compiler generated
6247 information that more exactly describes the program's run-time stack.
6248 By using this information, GDB is able to provide more robust stack
6251 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6252 have been updated to use a new backtrace mechanism which includes
6253 DWARF 2 CFI support.
6257 GDB's remote protocol has been extended to include support for hosted
6258 file I/O (where the remote target uses GDB's file system). See GDB's
6259 remote protocol documentation for details.
6261 * All targets using the new architecture framework.
6263 All of GDB's targets have been updated to use the new internal
6264 architecture framework. The way is now open for future GDB releases
6265 to include cross-architecture native debugging support (i386 on amd64,
6268 * GNU/Linux's Thread Local Storage (TLS)
6270 GDB now includes support for for the GNU/Linux implementation of
6271 per-thread variables.
6273 * GNU/Linux's Native POSIX Thread Library (NPTL)
6275 GDB's thread code has been updated to work with either the new
6276 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6278 * Separate debug info.
6280 GDB, in conjunction with BINUTILS, now supports a mechanism for
6281 automatically loading debug information from a separate file. Instead
6282 of shipping full debug and non-debug versions of system libraries,
6283 system integrators can now instead ship just the stripped libraries
6284 and optional debug files.
6286 * DWARF 2 Location Expressions
6288 DWARF 2 Location Expressions allow the compiler to more completely
6289 describe the location of variables (even in optimized code) to the
6292 GDB now includes preliminary support for location expressions (support
6293 for DW_OP_piece is still missing).
6297 A number of long standing bugs that caused GDB to die while starting a
6298 Java application have been fixed. GDB's Java support is now
6299 considered "useable".
6301 * GNU/Linux support for fork, vfork, and exec.
6303 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6304 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6307 * GDB supports logging output to a file
6309 There are two new commands, "set logging" and "show logging", which can be
6310 used to capture GDB's output to a file.
6312 * The meaning of "detach" has changed for gdbserver
6314 The "detach" command will now resume the application, as documented. To
6315 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6318 * d10v, m68hc11 `regs' command deprecated
6320 The `info registers' command has been updated so that it displays the
6321 registers using a format identical to the old `regs' command.
6325 A new command, "maint set profile on/off", has been added. This command can
6326 be used to enable or disable profiling while running GDB, to profile a
6327 session or a set of commands. In addition there is a new configure switch,
6328 "--enable-profiling", which will cause GDB to be compiled with profiling
6329 data, for more informative profiling results.
6331 * Default MI syntax changed to "mi2".
6333 The default MI (machine interface) syntax, enabled by the command line
6334 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6335 "mi1", can be enabled by specifying the option "-i=mi1".
6337 Support for the original "mi0" syntax (included in GDB 5.0) has been
6340 Fix for gdb/192: removed extraneous space when displaying frame level.
6341 Fix for gdb/672: update changelist is now output in mi list format.
6342 Fix for gdb/702: a -var-assign that updates the value now shows up
6343 in a subsequent -var-update.
6345 * New native configurations.
6347 FreeBSD/amd64 x86_64-*-freebsd*
6349 * Multi-arched targets.
6351 HP/PA HPUX11 hppa*-*-hpux*
6352 Renesas M32R/D w/simulator m32r-*-elf*
6354 * OBSOLETE configurations and files
6356 Configurations that have been declared obsolete in this release have
6357 been commented out. Unless there is activity to revive these
6358 configurations, the next release of GDB will have their sources
6359 permanently REMOVED.
6361 Z8000 simulator z8k-zilog-none or z8ksim
6362 Matsushita MN10200 w/simulator mn10200-*-*
6363 H8/500 simulator h8500-hitachi-hms or h8500hms
6364 HP/PA running BSD hppa*-*-bsd*
6365 HP/PA running OSF/1 hppa*-*-osf*
6366 HP/PA Pro target hppa*-*-pro*
6367 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6368 Sequent family i[3456]86-sequent-sysv4*
6369 i[3456]86-sequent-sysv*
6370 i[3456]86-sequent-bsd*
6371 Tsqware Sparclet sparclet-*-*
6372 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6374 * REMOVED configurations and files
6377 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6378 IBM AIX PS/2 i[3456]86-*-aix
6379 i386 running Mach 3.0 i[3456]86-*-mach3*
6380 i386 running Mach i[3456]86-*-mach*
6381 i386 running OSF/1 i[3456]86-*osf1mk*
6382 HP/Apollo 68k Family m68*-apollo*-sysv*,
6384 m68*-hp-bsd*, m68*-hp-hpux*
6385 Argonaut Risc Chip (ARC) arc-*-*
6386 Mitsubishi D30V d30v-*-*
6387 Fujitsu FR30 fr30-*-elf*
6388 OS/9000 i[34]86-*-os9k
6389 I960 with MON960 i960-*-coff
6391 * MIPS $fp behavior changed
6393 The convenience variable $fp, for the MIPS, now consistently returns
6394 the address of the current frame's base. Previously, depending on the
6395 context, $fp could refer to either $sp or the current frame's base
6396 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6397 The GNU Source-Level Debugger''.
6399 *** Changes in GDB 5.3:
6401 * GNU/Linux shared library multi-threaded performance improved.
6403 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6404 `/proc', in preference to `ptrace' for memory reads. This may result
6405 in an improvement in the start-up time of multi-threaded, shared
6406 library applications when run under GDB. One GDB user writes: ``loads
6407 shared libs like mad''.
6409 * ``gdbserver'' now supports multi-threaded applications on some targets
6411 Support for debugging multi-threaded applications which use
6412 the GNU/Linux LinuxThreads package has been added for
6413 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6414 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6416 * GDB now supports C/C++ preprocessor macros.
6418 GDB now expands preprocessor macro invocations in C/C++ expressions,
6419 and provides various commands for showing macro definitions and how
6422 The new command `macro expand EXPRESSION' expands any macro
6423 invocations in expression, and shows the result.
6425 The new command `show macro MACRO-NAME' shows the definition of the
6426 macro named MACRO-NAME, and where it was defined.
6428 Most compilers don't include information about macros in the debugging
6429 information by default. In GCC 3.1, for example, you need to compile
6430 your program with the options `-gdwarf-2 -g3'. If the macro
6431 information is present in the executable, GDB will read it.
6433 * Multi-arched targets.
6435 DEC Alpha (partial) alpha*-*-*
6436 DEC VAX (partial) vax-*-*
6438 National Semiconductor NS32000 (partial) ns32k-*-*
6439 Motorola 68000 (partial) m68k-*-*
6440 Motorola MCORE mcore-*-*
6444 Fujitsu FRV architecture added by Red Hat frv*-*-*
6447 * New native configurations
6449 Alpha NetBSD alpha*-*-netbsd*
6450 SH NetBSD sh*-*-netbsdelf*
6451 MIPS NetBSD mips*-*-netbsd*
6452 UltraSPARC NetBSD sparc64-*-netbsd*
6454 * OBSOLETE configurations and files
6456 Configurations that have been declared obsolete in this release have
6457 been commented out. Unless there is activity to revive these
6458 configurations, the next release of GDB will have their sources
6459 permanently REMOVED.
6461 Mitsubishi D30V d30v-*-*
6462 OS/9000 i[34]86-*-os9k
6463 IBM AIX PS/2 i[3456]86-*-aix
6464 Fujitsu FR30 fr30-*-elf*
6465 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6466 Argonaut Risc Chip (ARC) arc-*-*
6467 i386 running Mach 3.0 i[3456]86-*-mach3*
6468 i386 running Mach i[3456]86-*-mach*
6469 i386 running OSF/1 i[3456]86-*osf1mk*
6470 HP/Apollo 68k Family m68*-apollo*-sysv*,
6472 m68*-hp-bsd*, m68*-hp-hpux*
6473 I960 with MON960 i960-*-coff
6475 * OBSOLETE languages
6477 CHILL, a Pascal like language used by telecommunications companies.
6479 * REMOVED configurations and files
6481 AMD 29k family via UDI a29k-amd-udi, udi29k
6482 A29K VxWorks a29k-*-vxworks
6483 AMD 29000 embedded, using EBMON a29k-none-none
6484 AMD 29000 embedded with COFF a29k-none-coff
6485 AMD 29000 embedded with a.out a29k-none-aout
6487 testsuite/gdb.hp/gdb.threads-hp/ directory
6489 * New command "set max-user-call-depth <nnn>"
6491 This command allows the user to limit the call depth of user-defined
6492 commands. The default is 1024.
6494 * Changes in FreeBSD/i386 native debugging.
6496 Support for the "generate-core-file" has been added.
6498 * New commands "dump", "append", and "restore".
6500 These commands allow data to be copied from target memory
6501 to a bfd-format or binary file (dump and append), and back
6502 from a file into memory (restore).
6504 * Improved "next/step" support on multi-processor Alpha Tru64.
6506 The previous single-step mechanism could cause unpredictable problems,
6507 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6508 of a software single-step mechanism prevents this.
6510 *** Changes in GDB 5.2.1:
6518 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6519 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6520 Fix, by Joel Brobecker imported from mainline.
6522 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6523 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6524 Fix, by Fred Fish, imported from mainline.
6526 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6527 Surprisingly enough, it works now.
6528 By Michal Ludvig, imported from mainline.
6530 i386 hardware watchpoint support:
6531 avoid misses on second run for some targets.
6532 By Pierre Muller, imported from mainline.
6534 *** Changes in GDB 5.2:
6536 * New command "set trust-readonly-sections on[off]".
6538 This command is a hint that tells gdb that read-only sections
6539 really are read-only (ie. that their contents will not change).
6540 In this mode, gdb will go to the object file rather than the
6541 target to read memory from read-only sections (such as ".text").
6542 This can be a significant performance improvement on some
6543 (notably embedded) targets.
6545 * New command "generate-core-file" (or "gcore").
6547 This new gdb command allows the user to drop a core file of the child
6548 process state at any time. So far it's been implemented only for
6549 GNU/Linux and Solaris, but should be relatively easily ported to other
6550 hosts. Argument is core file name (defaults to core.<pid>).
6552 * New command line option
6554 GDB now accepts --pid or -p followed by a process id.
6556 * Change in command line behavior -- corefiles vs. process ids.
6558 There is a subtle behavior in the way in which GDB handles
6559 command line arguments. The first non-flag argument is always
6560 a program to debug, but the second non-flag argument may either
6561 be a corefile or a process id. Previously, GDB would attempt to
6562 open the second argument as a corefile, and if that failed, would
6563 issue a superfluous error message and then attempt to attach it as
6564 a process. Now, if the second argument begins with a non-digit,
6565 it will be treated as a corefile. If it begins with a digit,
6566 GDB will attempt to attach it as a process, and if no such process
6567 is found, will then attempt to open it as a corefile.
6569 * Changes in ARM configurations.
6571 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6572 configuration is fully multi-arch.
6574 * New native configurations
6576 ARM NetBSD arm*-*-netbsd*
6577 x86 OpenBSD i[3456]86-*-openbsd*
6578 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6579 Sparc64 running FreeBSD sparc64-*-freebsd*
6583 Sanyo XStormy16 xstormy16-elf
6585 * OBSOLETE configurations and files
6587 Configurations that have been declared obsolete in this release have
6588 been commented out. Unless there is activity to revive these
6589 configurations, the next release of GDB will have their sources
6590 permanently REMOVED.
6592 AMD 29k family via UDI a29k-amd-udi, udi29k
6593 A29K VxWorks a29k-*-vxworks
6594 AMD 29000 embedded, using EBMON a29k-none-none
6595 AMD 29000 embedded with COFF a29k-none-coff
6596 AMD 29000 embedded with a.out a29k-none-aout
6598 testsuite/gdb.hp/gdb.threads-hp/ directory
6600 * REMOVED configurations and files
6602 TI TMS320C80 tic80-*-*
6604 PowerPC Solaris powerpcle-*-solaris*
6605 PowerPC Windows NT powerpcle-*-cygwin32
6606 PowerPC Netware powerpc-*-netware*
6607 Harris/CXUX m88k m88*-harris-cxux*
6608 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6609 ns32k-utek-sysv* ns32k-utek-*
6610 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6611 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6612 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6613 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6614 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6616 * Changes to command line processing
6618 The new `--args' feature can be used to specify command-line arguments
6619 for the inferior from gdb's command line.
6621 * Changes to key bindings
6623 There is a new `operate-and-get-next' function bound to `C-o'.
6625 *** Changes in GDB 5.1.1
6627 Fix compile problem on DJGPP.
6629 Fix a problem with floating-point registers on the i386 being
6632 Fix to stop GDB crashing on .debug_str debug info.
6634 Numerous documentation fixes.
6636 Numerous testsuite fixes.
6638 *** Changes in GDB 5.1:
6640 * New native configurations
6642 Alpha FreeBSD alpha*-*-freebsd*
6643 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6644 MIPS GNU/Linux mips*-*-linux*
6645 MIPS SGI Irix 6.x mips*-sgi-irix6*
6646 ia64 AIX ia64-*-aix*
6647 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6651 Motorola 68HC11 and 68HC12 m68hc11-elf
6653 UltraSparc running GNU/Linux sparc64-*-linux*
6655 * OBSOLETE configurations and files
6657 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6658 Harris/CXUX m88k m88*-harris-cxux*
6659 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6660 ns32k-utek-sysv* ns32k-utek-*
6661 TI TMS320C80 tic80-*-*
6663 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6664 PowerPC Solaris powerpcle-*-solaris*
6665 PowerPC Windows NT powerpcle-*-cygwin32
6666 PowerPC Netware powerpc-*-netware*
6667 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6668 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6669 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6670 Apple Macintosh (MPW) host N/A
6672 stuff.c (Program to stuff files into a specially prepared space in kdb)
6673 kdb-start.c (Main loop for the standalone kernel debugger)
6675 Configurations that have been declared obsolete in this release have
6676 been commented out. Unless there is activity to revive these
6677 configurations, the next release of GDB will have their sources
6678 permanently REMOVED.
6680 * REMOVED configurations and files
6682 Altos 3068 m68*-altos-*
6683 Convex c1-*-*, c2-*-*
6685 ARM RISCix arm-*-* (as host)
6689 * GDB has been converted to ISO C.
6691 GDB's source code has been converted to ISO C. In particular, the
6692 sources are fully protoized, and rely on standard headers being
6697 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6699 * The MI enabled by default.
6701 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6702 revised and enabled by default. Packages which use GDB as a debugging
6703 engine behind a UI or another front end are encouraged to switch to
6704 using the GDB/MI interface, instead of the old annotations interface
6705 which is now deprecated.
6707 * Support for debugging Pascal programs.
6709 GDB now includes support for debugging Pascal programs. The following
6710 main features are supported:
6712 - Pascal-specific data types such as sets;
6714 - automatic recognition of Pascal sources based on file-name
6717 - Pascal-style display of data types, variables, and functions;
6719 - a Pascal expression parser.
6721 However, some important features are not yet supported.
6723 - Pascal string operations are not supported at all;
6725 - there are some problems with boolean types;
6727 - Pascal type hexadecimal constants are not supported
6728 because they conflict with the internal variables format;
6730 - support for Pascal objects and classes is not full yet;
6732 - unlike Pascal, GDB is case-sensitive for symbol names.
6734 * Changes in completion.
6736 Commands such as `shell', `run' and `set args', which pass arguments
6737 to inferior programs, now complete on file names, similar to what
6738 users expect at the shell prompt.
6740 Commands which accept locations, such as `disassemble', `print',
6741 `breakpoint', `until', etc. now complete on filenames as well as
6742 program symbols. Thus, if you type "break foob TAB", and the source
6743 files linked into the programs include `foobar.c', that file name will
6744 be one of the candidates for completion. However, file names are not
6745 considered for completion after you typed a colon that delimits a file
6746 name from a name of a function in that file, as in "break foo.c:bar".
6748 `set demangle-style' completes on available demangling styles.
6750 * New platform-independent commands:
6752 It is now possible to define a post-hook for a command as well as a
6753 hook that runs before the command. For more details, see the
6754 documentation of `hookpost' in the GDB manual.
6756 * Changes in GNU/Linux native debugging.
6758 Support for debugging multi-threaded programs has been completely
6759 revised for all platforms except m68k and sparc. You can now debug as
6760 many threads as your system allows you to have.
6762 Attach/detach is supported for multi-threaded programs.
6764 Support for SSE registers was added for x86. This doesn't work for
6765 multi-threaded programs though.
6767 * Changes in MIPS configurations.
6769 Multi-arch support is enabled for all MIPS configurations.
6771 GDB can now be built as native debugger on SGI Irix 6.x systems for
6772 debugging n32 executables. (Debugging 64-bit executables is not yet
6775 * Unified support for hardware watchpoints in all x86 configurations.
6777 Most (if not all) native x86 configurations support hardware-assisted
6778 breakpoints and watchpoints in a unified manner. This support
6779 implements debug register sharing between watchpoints, which allows to
6780 put a virtually infinite number of watchpoints on the same address,
6781 and also supports watching regions up to 16 bytes with several debug
6784 The new maintenance command `maintenance show-debug-regs' toggles
6785 debugging print-outs in functions that insert, remove, and test
6786 watchpoints and hardware breakpoints.
6788 * Changes in the DJGPP native configuration.
6790 New command ``info dos sysinfo'' displays assorted information about
6791 the CPU, OS, memory, and DPMI server.
6793 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6794 display information about segment descriptors stored in GDT, LDT, and
6797 New commands ``info dos pde'' and ``info dos pte'' display entries
6798 from Page Directory and Page Tables (for now works with CWSDPMI only).
6799 New command ``info dos address-pte'' displays the Page Table entry for
6800 a given linear address.
6802 GDB can now pass command lines longer than 126 characters to the
6803 program being debugged (requires an update to the libdbg.a library
6804 which is part of the DJGPP development kit).
6806 DWARF2 debug info is now supported.
6808 It is now possible to `step' and `next' through calls to `longjmp'.
6810 * Changes in documentation.
6812 All GDB documentation was converted to GFDL, the GNU Free
6813 Documentation License.
6815 Tracepoints-related commands are now fully documented in the GDB
6818 TUI, the Text-mode User Interface, is now documented in the manual.
6820 Tracepoints-related commands are now fully documented in the GDB
6823 The "GDB Internals" manual now has an index. It also includes
6824 documentation of `ui_out' functions, GDB coding standards, x86
6825 hardware watchpoints, and memory region attributes.
6827 * GDB's version number moved to ``version.in''
6829 The Makefile variable VERSION has been replaced by the file
6830 ``version.in''. People creating GDB distributions should update the
6831 contents of this file.
6835 GUD support is now a standard part of the EMACS distribution.
6837 *** Changes in GDB 5.0:
6839 * Improved support for debugging FP programs on x86 targets
6841 Unified and much-improved support for debugging floating-point
6842 programs on all x86 targets. In particular, ``info float'' now
6843 displays the FP registers in the same format on all x86 targets, with
6844 greater level of detail.
6846 * Improvements and bugfixes in hardware-assisted watchpoints
6848 It is now possible to watch array elements, struct members, and
6849 bitfields with hardware-assisted watchpoints. Data-read watchpoints
6850 on x86 targets no longer erroneously trigger when the address is
6853 * Improvements in the native DJGPP version of GDB
6855 The distribution now includes all the scripts and auxiliary files
6856 necessary to build the native DJGPP version on MS-DOS/MS-Windows
6857 machines ``out of the box''.
6859 The DJGPP version can now debug programs that use signals. It is
6860 possible to catch signals that happened in the debuggee, deliver
6861 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
6862 would kill the program being debugged.) Programs that hook hardware
6863 interrupts (keyboard, timer, etc.) can also be debugged.
6865 It is now possible to debug DJGPP programs that redirect their
6866 standard handles or switch them to raw (as opposed to cooked) mode, or
6867 even close them. The command ``run < foo > bar'' works as expected,
6868 and ``info terminal'' reports useful information about the debuggee's
6869 terminal, including raw/cooked mode, redirection, etc.
6871 The DJGPP version now uses termios functions for console I/O, which
6872 enables debugging graphics programs. Interrupting GDB with Ctrl-C
6875 DOS-style file names with drive letters are now fully supported by
6878 It is now possible to debug DJGPP programs that switch their working
6879 directory. It is also possible to rerun the debuggee any number of
6880 times without restarting GDB; thus, you can use the same setup,
6881 breakpoints, etc. for many debugging sessions.
6883 * New native configurations
6885 ARM GNU/Linux arm*-*-linux*
6886 PowerPC GNU/Linux powerpc-*-linux*
6890 Motorola MCore mcore-*-*
6891 x86 VxWorks i[3456]86-*-vxworks*
6892 PowerPC VxWorks powerpc-*-vxworks*
6893 TI TMS320C80 tic80-*-*
6895 * OBSOLETE configurations
6897 Altos 3068 m68*-altos-*
6898 Convex c1-*-*, c2-*-*
6900 ARM RISCix arm-*-* (as host)
6903 Configurations that have been declared obsolete will be commented out,
6904 but the code will be left in place. If there is no activity to revive
6905 these configurations before the next release of GDB, the sources will
6906 be permanently REMOVED.
6908 * Gould support removed
6910 Support for the Gould PowerNode and NP1 has been removed.
6912 * New features for SVR4
6914 On SVR4 native platforms (such as Solaris), if you attach to a process
6915 without first loading a symbol file, GDB will now attempt to locate and
6916 load symbols from the running process's executable file.
6918 * Many C++ enhancements
6920 C++ support has been greatly improved. Overload resolution now works properly
6921 in almost all cases. RTTI support is on the way.
6923 * Remote targets can connect to a sub-program
6925 A popen(3) style serial-device has been added. This device starts a
6926 sub-process (such as a stand-alone simulator) and then communicates
6927 with that. The sub-program to run is specified using the syntax
6928 ``|<program> <args>'' vis:
6930 (gdb) set remotedebug 1
6931 (gdb) target extended-remote |mn10300-elf-sim program-args
6933 * MIPS 64 remote protocol
6935 A long standing bug in the mips64 remote protocol where by GDB
6936 expected certain 32 bit registers (ex SR) to be transfered as 32
6937 instead of 64 bits has been fixed.
6939 The command ``set remote-mips64-transfers-32bit-regs on'' has been
6940 added to provide backward compatibility with older versions of GDB.
6942 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
6944 The command ``set remotebinarydownload'' command has been replaced by
6945 ``set remote X-packet''. Other commands in ``set remote'' family
6946 include ``set remote P-packet''.
6948 * Breakpoint commands accept ranges.
6950 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
6951 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
6952 ``tracepoint passcount'' also accepts a range of tracepoints.
6954 * ``apropos'' command added.
6956 The ``apropos'' command searches through command names and
6957 documentation strings, printing out matches, making it much easier to
6958 try to find a command that does what you are looking for.
6962 A new machine oriented interface (MI) has been added to GDB. This
6963 interface is designed for debug environments running GDB as a separate
6964 process. This is part of the long term libGDB project. See the
6965 "GDB/MI" chapter of the GDB manual for further information. It can be
6966 enabled by configuring with:
6968 .../configure --enable-gdbmi
6970 *** Changes in GDB-4.18:
6972 * New native configurations
6974 HP-UX 10.20 hppa*-*-hpux10.20
6975 HP-UX 11.x hppa*-*-hpux11.0*
6976 M68K GNU/Linux m68*-*-linux*
6980 Fujitsu FR30 fr30-*-elf*
6981 Intel StrongARM strongarm-*-*
6982 Mitsubishi D30V d30v-*-*
6984 * OBSOLETE configurations
6986 Gould PowerNode, NP1 np1-*-*, pn-*-*
6988 Configurations that have been declared obsolete will be commented out,
6989 but the code will be left in place. If there is no activity to revive
6990 these configurations before the next release of GDB, the sources will
6991 be permanently REMOVED.
6995 As a compatibility experiment, GDB's source files buildsym.h and
6996 buildsym.c have been converted to pure standard C, no longer
6997 containing any K&R compatibility code. We believe that all systems in
6998 use today either come with a standard C compiler, or have a GCC port
6999 available. If this is not true, please report the affected
7000 configuration to bug-gdb@gnu.org immediately. See the README file for
7001 information about getting a standard C compiler if you don't have one
7006 GDB now uses readline 2.2.
7008 * set extension-language
7010 You can now control the mapping between filename extensions and source
7011 languages by using the `set extension-language' command. For instance,
7012 you can ask GDB to treat .c files as C++ by saying
7013 set extension-language .c c++
7014 The command `info extensions' lists all of the recognized extensions
7015 and their associated languages.
7017 * Setting processor type for PowerPC and RS/6000
7019 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7020 you can use the `set processor' command to specify what variant of the
7021 PowerPC family you are debugging. The command
7025 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7026 following PowerPC and RS6000 variants:
7028 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7029 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7031 403GC IBM PowerPC 403GC
7032 505 Motorola PowerPC 505
7033 860 Motorola PowerPC 860 or 850
7034 601 Motorola PowerPC 601
7035 602 Motorola PowerPC 602
7036 603 Motorola/IBM PowerPC 603 or 603e
7037 604 Motorola PowerPC 604 or 604e
7038 750 Motorola/IBM PowerPC 750 or 750
7040 At the moment, this command just tells GDB what to name the
7041 special-purpose processor registers. Since almost all the affected
7042 registers are inaccessible to user-level programs, this command is
7043 only useful for remote debugging in its present form.
7047 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7048 more extensive support for HP-UX. Added features include shared
7049 library support, kernel threads and hardware watchpoints for 11.00,
7050 support for HP's ANSI C and C++ compilers, and a compatibility mode
7051 for xdb and dbx commands.
7055 HP's donation includes the new concept of catchpoints, which is a
7056 generalization of the old catch command. On HP-UX, it is now possible
7057 to catch exec, fork, and vfork, as well as library loading.
7059 This means that the existing catch command has changed; its first
7060 argument now specifies the type of catch to be set up. See the
7061 output of "help catch" for a list of catchpoint types.
7063 * Debugging across forks
7065 On HP-UX, you can choose which process to debug when a fork() happens
7070 HP has donated a curses-based terminal user interface (TUI). To get
7071 it, build with --enable-tui. Although this can be enabled for any
7072 configuration, at present it only works for native HP debugging.
7074 * GDB remote protocol additions
7076 A new protocol packet 'X' that writes binary data is now available.
7077 Default behavior is to try 'X', then drop back to 'M' if the stub
7078 fails to respond. The settable variable `remotebinarydownload'
7079 allows explicit control over the use of 'X'.
7081 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7082 full 64-bit address. The command
7084 set remoteaddresssize 32
7086 can be used to revert to the old behaviour. For existing remote stubs
7087 the change should not be noticed, as the additional address information
7090 In order to assist in debugging stubs, you may use the maintenance
7091 command `packet' to send any text string to the stub. For instance,
7093 maint packet heythere
7095 sends the packet "$heythere#<checksum>". Note that it is very easy to
7096 disrupt a debugging session by sending the wrong packet at the wrong
7099 The compare-sections command allows you to compare section data on the
7100 target to what is in the executable file without uploading or
7101 downloading, by comparing CRC checksums.
7103 * Tracing can collect general expressions
7105 You may now collect general expressions at tracepoints. This requires
7106 further additions to the target-side stub; see tracepoint.c and
7107 doc/agentexpr.texi for further details.
7109 * mask-address variable for Mips
7111 For Mips targets, you may control the zeroing of the upper 32 bits of
7112 a 64-bit address by entering `set mask-address on'. This is mainly
7113 of interest to users of embedded R4xxx and R5xxx processors.
7115 * Higher serial baud rates
7117 GDB's serial code now allows you to specify baud rates 57600, 115200,
7118 230400, and 460800 baud. (Note that your host system may not be able
7119 to achieve all of these rates.)
7123 The i960 configuration now includes an initial implementation of a
7124 builtin simulator, contributed by Jim Wilson.
7127 *** Changes in GDB-4.17:
7129 * New native configurations
7131 Alpha GNU/Linux alpha*-*-linux*
7132 Unixware 2.x i[3456]86-unixware2*
7133 Irix 6.x mips*-sgi-irix6*
7134 PowerPC GNU/Linux powerpc-*-linux*
7135 PowerPC Solaris powerpcle-*-solaris*
7136 Sparc GNU/Linux sparc-*-linux*
7137 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7141 Argonaut Risc Chip (ARC) arc-*-*
7142 Hitachi H8/300S h8300*-*-*
7143 Matsushita MN10200 w/simulator mn10200-*-*
7144 Matsushita MN10300 w/simulator mn10300-*-*
7145 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7146 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7147 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7148 Mitsubishi D10V w/simulator d10v-*-*
7149 Mitsubishi M32R/D w/simulator m32r-*-elf*
7150 Tsqware Sparclet sparclet-*-*
7151 NEC V850 w/simulator v850-*-*
7153 * New debugging protocols
7155 ARM with RDI protocol arm*-*-*
7156 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7157 DDB and LSI variants of PMON protocol mips*-*-*
7158 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7159 PowerPC with SDS protocol powerpc{,le}-*-eabi
7160 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7164 All configurations can now understand and use the DWARF 2 debugging
7165 format. The choice is automatic, if the symbol file contains DWARF 2
7170 GDB now includes basic Java language support. This support is
7171 only useful with Java compilers that produce native machine code.
7173 * solib-absolute-prefix and solib-search-path
7175 For SunOS and SVR4 shared libraries, you may now set the prefix for
7176 loading absolute shared library symbol files, and the search path for
7177 locating non-absolute shared library symbol files.
7179 * Live range splitting
7181 GDB can now effectively debug code for which GCC has performed live
7182 range splitting as part of its optimization. See gdb/doc/LRS for
7183 more details on the expected format of the stabs information.
7187 GDB's support for the GNU Hurd, including thread debugging, has been
7188 updated to work with current versions of the Hurd.
7192 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7193 instruction set. ARM GDB automatically detects when Thumb
7194 instructions are in use, and adjusts disassembly and backtracing
7199 GDB's MIPS target configurations now handle the MIP16 16-bit
7204 GDB now includes support for overlays; if an executable has been
7205 linked such that multiple sections are based at the same address, GDB
7206 will decide which section to use for symbolic info. You can choose to
7207 control the decision manually, using overlay commands, or implement
7208 additional target-side support and use "overlay load-target" to bring
7209 in the overlay mapping. Do "help overlay" for more detail.
7213 The command "info symbol <address>" displays information about
7214 the symbol at the specified address.
7218 The standard remote protocol now includes an extension that allows
7219 asynchronous collection and display of trace data. This requires
7220 extensive support in the target-side debugging stub. Tracing mode
7221 includes a new interaction mode in GDB and new commands: see the
7222 file tracepoint.c for more details.
7226 Configurations for embedded MIPS now include a simulator contributed
7227 by Cygnus Solutions. The simulator supports the instruction sets
7228 of most MIPS variants.
7232 Sparc configurations may now include the ERC32 simulator contributed
7233 by the European Space Agency. The simulator is not built into
7234 Sparc targets by default; configure with --enable-sim to include it.
7238 For target configurations that may include multiple variants of a
7239 basic architecture (such as MIPS and SH), you may now set the
7240 architecture explicitly. "set arch" sets, "info arch" lists
7241 the possible architectures.
7243 *** Changes in GDB-4.16:
7245 * New native configurations
7247 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7248 M68K NetBSD m68k-*-netbsd*
7249 PowerPC AIX 4.x powerpc-*-aix*
7250 PowerPC MacOS powerpc-*-macos*
7251 PowerPC Windows NT powerpcle-*-cygwin32
7252 RS/6000 AIX 4.x rs6000-*-aix4*
7256 ARM with RDP protocol arm-*-*
7257 I960 with MON960 i960-*-coff
7258 MIPS VxWorks mips*-*-vxworks*
7259 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7260 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7262 Matra Sparclet sparclet-*-*
7266 The powerpc-eabi configuration now includes the PSIM simulator,
7267 contributed by Andrew Cagney, with assistance from Mike Meissner.
7268 PSIM is a very elaborate model of the PowerPC, including not only
7269 basic instruction set execution, but also details of execution unit
7270 performance and I/O hardware. See sim/ppc/README for more details.
7274 GDB now works with Solaris 2.5.
7276 * Windows 95/NT native
7278 GDB will now work as a native debugger on Windows 95 and Windows NT.
7279 To build it from source, you must use the "gnu-win32" environment,
7280 which uses a DLL to emulate enough of Unix to run the GNU tools.
7281 Further information, binaries, and sources are available at
7282 ftp.cygnus.com, under pub/gnu-win32.
7284 * dont-repeat command
7286 If a user-defined command includes the command `dont-repeat', then the
7287 command will not be repeated if the user just types return. This is
7288 useful if the command is time-consuming to run, so that accidental
7289 extra keystrokes don't run the same command many times.
7291 * Send break instead of ^C
7293 The standard remote protocol now includes an option to send a break
7294 rather than a ^C to the target in order to interrupt it. By default,
7295 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7297 * Remote protocol timeout
7299 The standard remote protocol includes a new variable `remotetimeout'
7300 that allows you to set the number of seconds before GDB gives up trying
7301 to read from the target. The default value is 2.
7303 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7305 By default GDB will automatically keep track of objects as they are
7306 loaded and unloaded by the dynamic linker. By using the command `set
7307 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7308 when shared library events occur, thus allowing you to set breakpoints
7309 in shared libraries which are explicitly loaded by the inferior.
7311 Note this feature does not work on hpux8. On hpux9 you must link
7312 /usr/lib/end.o into your program. This feature should work
7313 automatically on hpux10.
7315 * Irix 5.x hardware watchpoint support
7317 Irix 5 configurations now support the use of hardware watchpoints.
7319 * Mips protocol "SYN garbage limit"
7321 When debugging a Mips target using the `target mips' protocol, you
7322 may set the number of characters that GDB will ignore by setting
7323 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7324 every character. The default value is 1050.
7326 * Recording and replaying remote debug sessions
7328 If you set `remotelogfile' to the name of a file, gdb will write to it
7329 a recording of a remote debug session. This recording may then be
7330 replayed back to gdb using "gdbreplay". See gdbserver/README for
7331 details. This is useful when you have a problem with GDB while doing
7332 remote debugging; you can make a recording of the session and send it
7333 to someone else, who can then recreate the problem.
7335 * Speedups for remote debugging
7337 GDB includes speedups for downloading and stepping MIPS systems using
7338 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7339 and more efficient S-record downloading.
7341 * Memory use reductions and statistics collection
7343 GDB now uses less memory and reports statistics about memory usage.
7344 Try the `maint print statistics' command, for example.
7346 *** Changes in GDB-4.15:
7348 * Psymtabs for XCOFF
7350 The symbol reader for AIX GDB now uses partial symbol tables. This
7351 can greatly improve startup time, especially for large executables.
7353 * Remote targets use caching
7355 Remote targets now use a data cache to speed up communication with the
7356 remote side. The data cache could lead to incorrect results because
7357 it doesn't know about volatile variables, thus making it impossible to
7358 debug targets which use memory mapped I/O devices. `set remotecache
7359 off' turns the data cache off.
7361 * Remote targets may have threads
7363 The standard remote protocol now includes support for multiple threads
7364 in the target system, using new protocol commands 'H' and 'T'. See
7365 gdb/remote.c for details.
7369 If GDB is configured with `--enable-netrom', then it will include
7370 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7371 acts as though it is a bank of ROM on the target board, but you can
7372 write into it over the network. GDB's support consists only of
7373 support for fast loading into the emulated ROM; to debug, you must use
7374 another protocol, such as standard remote protocol. The usual
7375 sequence is something like
7377 target nrom <netrom-hostname>
7379 target remote <netrom-hostname>:1235
7383 GDB now includes support for the Apple Macintosh, as a host only. It
7384 may be run as either an MPW tool or as a standalone application, and
7385 it can debug through the serial port. All the usual GDB commands are
7386 available, but to the target command, you must supply "serial" as the
7387 device type instead of "/dev/ttyXX". See mpw-README in the main
7388 directory for more information on how to build. The MPW configuration
7389 scripts */mpw-config.in support only a few targets, and only the
7390 mips-idt-ecoff target has been tested.
7394 GDB configuration now uses autoconf. This is not user-visible,
7395 but does simplify configuration and building.
7399 GDB now supports hpux10.
7401 *** Changes in GDB-4.14:
7403 * New native configurations
7405 x86 FreeBSD i[345]86-*-freebsd
7406 x86 NetBSD i[345]86-*-netbsd
7407 NS32k NetBSD ns32k-*-netbsd
7408 Sparc NetBSD sparc-*-netbsd
7412 A29K VxWorks a29k-*-vxworks
7413 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7414 CPU32 EST-300 emulator m68*-*-est*
7415 PowerPC ELF powerpc-*-elf
7418 * Alpha OSF/1 support for procfs
7420 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7421 possible to attach to running processes. As the mounting of the /proc
7422 filesystem is optional on the Alpha, GDB automatically determines
7423 the availability of /proc during startup. This can lead to problems
7424 if /proc is unmounted after GDB has been started.
7426 * Arguments to user-defined commands
7428 User commands may accept up to 10 arguments separated by whitespace.
7429 Arguments are accessed within the user command via $arg0..$arg9. A
7432 print $arg0 + $arg1 + $arg2
7434 To execute the command use:
7437 Defines the command "adder" which prints the sum of its three arguments.
7438 Note the arguments are text substitutions, so they may reference variables,
7439 use complex expressions, or even perform inferior function calls.
7441 * New `if' and `while' commands
7443 This makes it possible to write more sophisticated user-defined
7444 commands. Both commands take a single argument, which is the
7445 expression to evaluate, and must be followed by the commands to
7446 execute, one per line, if the expression is nonzero, the list being
7447 terminated by the word `end'. The `if' command list may include an
7448 `else' word, which causes the following commands to be executed only
7449 if the expression is zero.
7451 * Fortran source language mode
7453 GDB now includes partial support for Fortran 77. It will recognize
7454 Fortran programs and can evaluate a subset of Fortran expressions, but
7455 variables and functions may not be handled correctly. GDB will work
7456 with G77, but does not yet know much about symbols emitted by other
7459 * Better HPUX support
7461 Most debugging facilities now work on dynamic executables for HPPAs
7462 running hpux9 or later. You can attach to running dynamically linked
7463 processes, but by default the dynamic libraries will be read-only, so
7464 for instance you won't be able to put breakpoints in them. To change
7465 that behavior do the following before running the program:
7471 This will cause the libraries to be mapped private and read-write.
7472 To revert to the normal behavior, do this:
7478 You cannot set breakpoints or examine data in the library until after
7479 the library is loaded if the function/data symbols do not have
7482 GDB can now also read debug symbols produced by the HP C compiler on
7483 HPPAs (sorry, no C++, Fortran or 68k support).
7485 * Target byte order now dynamically selectable
7487 You can choose which byte order to use with a target system, via the
7488 commands "set endian big" and "set endian little", and you can see the
7489 current setting by using "show endian". You can also give the command
7490 "set endian auto", in which case GDB will use the byte order
7491 associated with the executable. Currently, only embedded MIPS
7492 configurations support dynamic selection of target byte order.
7494 * New DOS host serial code
7496 This version uses DPMI interrupts to handle buffered I/O, so you
7497 no longer need to run asynctsr when debugging boards connected to
7500 *** Changes in GDB-4.13:
7502 * New "complete" command
7504 This lists all the possible completions for the rest of the line, if it
7505 were to be given as a command itself. This is intended for use by emacs.
7507 * Trailing space optional in prompt
7509 "set prompt" no longer adds a space for you after the prompt you set. This
7510 allows you to set a prompt which ends in a space or one that does not.
7512 * Breakpoint hit counts
7514 "info break" now displays a count of the number of times the breakpoint
7515 has been hit. This is especially useful in conjunction with "ignore"; you
7516 can ignore a large number of breakpoint hits, look at the breakpoint info
7517 to see how many times the breakpoint was hit, then run again, ignoring one
7518 less than that number, and this will get you quickly to the last hit of
7521 * Ability to stop printing at NULL character
7523 "set print null-stop" will cause GDB to stop printing the characters of
7524 an array when the first NULL is encountered. This is useful when large
7525 arrays actually contain only short strings.
7527 * Shared library breakpoints
7529 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7530 breakpoints in shared libraries before the executable is run.
7532 * Hardware watchpoints
7534 There is a new hardware breakpoint for the watch command for sparclite
7535 targets. See gdb/sparclite/hw_breakpoint.note.
7537 Hardware watchpoints are also now supported under GNU/Linux.
7541 Annotations have been added. These are for use with graphical interfaces,
7542 and are still experimental. Currently only gdba.el uses these.
7544 * Improved Irix 5 support
7546 GDB now works properly with Irix 5.2.
7548 * Improved HPPA support
7550 GDB now works properly with the latest GCC and GAS.
7552 * New native configurations
7554 Sequent PTX4 i[34]86-sequent-ptx4
7555 HPPA running OSF/1 hppa*-*-osf*
7556 Atari TT running SVR4 m68*-*-sysv4*
7557 RS/6000 LynxOS rs6000-*-lynxos*
7561 OS/9000 i[34]86-*-os9k
7562 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7565 * Hitachi SH7000 and E7000-PC ICE support
7567 There is now support for communicating with the Hitachi E7000-PC ICE.
7568 This is available automatically when GDB is configured for the SH.
7572 As usual, a variety of small fixes and improvements, both generic
7573 and configuration-specific. See the ChangeLog for more detail.
7575 *** Changes in GDB-4.12:
7577 * Irix 5 is now supported
7581 GDB-4.12 on the HPPA has a number of changes which make it unable
7582 to debug the output from the currently released versions of GCC and
7583 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7584 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7585 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7588 *** Changes in GDB-4.11:
7590 * User visible changes:
7594 The "set remotedebug" option is now consistent between the mips remote
7595 target, remote targets using the gdb-specific protocol, UDI (AMD's
7596 debug protocol for the 29k) and the 88k bug monitor. It is now an
7597 integer specifying a debug level (normally 0 or 1, but 2 means more
7598 debugging info for the mips target).
7600 * DEC Alpha native support
7602 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7603 debug info, but GDB works fairly well with the DEC compiler and should
7604 work with a future GCC release. See the README file for a few
7605 Alpha-specific notes.
7607 * Preliminary thread implementation
7609 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7611 * LynxOS native and target support for 386
7613 This release has been hosted on LynxOS 2.2, and also can be configured
7614 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7617 * Improvements in C++ mangling/demangling.
7619 This release has much better g++ debugging, specifically in name
7620 mangling/demangling, virtual function calls, print virtual table,
7621 call methods, ...etc.
7623 *** Changes in GDB-4.10:
7625 * User visible changes:
7627 Remote debugging using the GDB-specific (`target remote') protocol now
7628 supports the `load' command. This is only useful if you have some
7629 other way of getting the stub to the target system, and you can put it
7630 somewhere in memory where it won't get clobbered by the download.
7632 Filename completion now works.
7634 When run under emacs mode, the "info line" command now causes the
7635 arrow to point to the line specified. Also, "info line" prints
7636 addresses in symbolic form (as well as hex).
7638 All vxworks based targets now support a user settable option, called
7639 vxworks-timeout. This option represents the number of seconds gdb
7640 should wait for responses to rpc's. You might want to use this if
7641 your vxworks target is, perhaps, a slow software simulator or happens
7642 to be on the far side of a thin network line.
7646 This release contains support for using a DEC alpha as a GDB host for
7647 cross debugging. Native alpha debugging is not supported yet.
7650 *** Changes in GDB-4.9:
7654 This is the first GDB release which is accompanied by a matching testsuite.
7655 The testsuite requires installation of dejagnu, which should be available
7656 via ftp from most sites that carry GNU software.
7660 'Cfront' style demangling has had its name changed to 'ARM' style, to
7661 emphasize that it was written from the specifications in the C++ Annotated
7662 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7663 disclaimers, it still generated too much confusion with users attempting to
7664 use gdb with AT&T cfront.
7668 GDB now uses a standard remote interface to a simulator library.
7669 So far, the library contains simulators for the Zilog Z8001/2, the
7670 Hitachi H8/300, H8/500 and Super-H.
7672 * New targets supported
7674 H8/300 simulator h8300-hitachi-hms or h8300hms
7675 H8/500 simulator h8500-hitachi-hms or h8500hms
7676 SH simulator sh-hitachi-hms or sh
7677 Z8000 simulator z8k-zilog-none or z8ksim
7678 IDT MIPS board over serial line mips-idt-ecoff
7680 Cross-debugging to GO32 targets is supported. It requires a custom
7681 version of the i386-stub.c module which is integrated with the
7682 GO32 memory extender.
7684 * New remote protocols
7686 MIPS remote debugging protocol.
7688 * New source languages supported
7690 This version includes preliminary support for Chill, a Pascal like language
7691 used by telecommunications companies. Chill support is also being integrated
7692 into the GNU compiler, but we don't know when it will be publically available.
7695 *** Changes in GDB-4.8:
7697 * HP Precision Architecture supported
7699 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7700 version of this support was available as a set of patches from the
7701 University of Utah. GDB does not support debugging of programs
7702 compiled with the HP compiler, because HP will not document their file
7703 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7704 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7706 Many problems in the preliminary version have been fixed.
7708 * Faster and better demangling
7710 We have improved template demangling and fixed numerous bugs in the GNU style
7711 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7712 character types (wchar_t) are now supported. Demangling of each symbol is now
7713 only done once, and is cached when the symbol table for a file is read in.
7714 This results in a small increase in memory usage for C programs, a moderate
7715 increase in memory usage for C++ programs, and a fantastic speedup in
7718 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7719 from the specifications in the Annotated Reference Manual, which AT&T's
7720 compiler does not actually implement.
7722 * G++ multiple inheritance compiler problem
7724 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7725 inheritance lattices was reworked to properly discover ambiguities. We
7726 recently found an example which causes this new algorithm to fail in a
7727 very subtle way, producing bad debug information for those classes.
7728 The file 'gcc.patch' (in this directory) can be applied to gcc to
7729 circumvent the problem. A future GCC release will contain a complete
7732 The previous G++ debug info problem (mentioned below for the gdb-4.7
7733 release) is fixed in gcc version 2.3.2.
7735 * Improved configure script
7737 The `configure' script will now attempt to guess your system type if
7738 you don't supply a host system type. The old scheme of supplying a
7739 host system triplet is preferable over using this. All the magic is
7740 done in the new `config.guess' script. Examine it for details.
7742 We have also brought our configure script much more in line with the FSF's
7743 version. It now supports the --with-xxx options. In particular,
7744 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7745 The resulting GDB will not be able to read arbitrary object file formats --
7746 only the format ``expected'' to be used on the configured target system.
7747 We hope to make this the default in a future release.
7749 * Documentation improvements
7751 There's new internal documentation on how to modify GDB, and how to
7752 produce clean changes to the code. We implore people to read it
7753 before submitting changes.
7755 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7756 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7757 `info' files are also provided. To build `info' files from scratch,
7758 you will need the latest `makeinfo' release, which will be available in
7759 a future texinfo-X.Y release.
7761 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7762 We're not sure exactly which versions have this problem, but it has
7763 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7764 or better. If that isn't possible, there is a patch in
7765 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7766 around this problem.
7770 GDB now supports array constants that can be used in expressions typed in by
7771 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7772 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7775 The new directory `gdb/sparclite' contains a program that demonstrates
7776 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7778 * New native hosts supported
7780 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7781 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7783 * New targets supported
7785 AMD 29k family via UDI a29k-amd-udi or udi29k
7787 * New file formats supported
7789 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7790 HPUX core files, and SCO 3.2v2 core files.
7794 Attaching to processes now works again; thanks for the many bug reports.
7796 We have also stomped on a bunch of core dumps caused by
7797 printf_filtered("%s") problems.
7799 We eliminated a copyright problem on the rpc and ptrace header files
7800 for VxWorks, which was discovered at the last minute during the 4.7
7801 release. You should now be able to build a VxWorks GDB.
7803 You can now interrupt gdb while an attached process is running. This
7804 will cause the attached process to stop, and give control back to GDB.
7806 We fixed problems caused by using too many file descriptors
7807 for reading symbols from object files and libraries. This was
7808 especially a problem for programs that used many (~100) shared
7811 The `step' command now only enters a subroutine if there is line number
7812 information for the subroutine. Otherwise it acts like the `next'
7813 command. Previously, `step' would enter subroutines if there was
7814 any debugging information about the routine. This avoids problems
7815 when using `cc -g1' on MIPS machines.
7817 * Internal improvements
7819 GDB's internal interfaces have been improved to make it easier to support
7820 debugging of multiple languages in the future.
7822 GDB now uses a common structure for symbol information internally.
7823 Minimal symbols (derived from linkage symbols in object files), partial
7824 symbols (from a quick scan of debug information), and full symbols
7825 contain a common subset of information, making it easier to write
7826 shared code that handles any of them.
7828 * New command line options
7830 We now accept --silent as an alias for --quiet.
7834 The memory-mapped-malloc library is now licensed under the GNU Library
7835 General Public License.
7837 *** Changes in GDB-4.7:
7839 * Host/native/target split
7841 GDB has had some major internal surgery to untangle the support for
7842 hosts and remote targets. Now, when you configure GDB for a remote
7843 target, it will no longer load in all of the support for debugging
7844 local programs on the host. When fully completed and tested, this will
7845 ensure that arbitrary host/target combinations are possible.
7847 The primary conceptual shift is to separate the non-portable code in
7848 GDB into three categories. Host specific code is required any time GDB
7849 is compiled on that host, regardless of the target. Target specific
7850 code relates to the peculiarities of the target, but can be compiled on
7851 any host. Native specific code is everything else: it can only be
7852 built when the host and target are the same system. Child process
7853 handling and core file support are two common `native' examples.
7855 GDB's use of /proc for controlling Unix child processes is now cleaner.
7856 It has been split out into a single module under the `target_ops' vector,
7857 plus two native-dependent functions for each system that uses /proc.
7859 * New hosts supported
7861 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
7862 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7863 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
7865 * New targets supported
7867 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7868 68030 and CPU32 m68030-*-*, m68332-*-*
7870 * New native hosts supported
7872 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
7873 (386bsd is not well tested yet)
7874 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
7876 * New file formats supported
7878 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
7879 supports reading of `a.out.adobe' object files, which are an a.out
7880 format extended with minimal information about multiple sections.
7884 `show copying' is the same as the old `info copying'.
7885 `show warranty' is the same as `info warrantee'.
7886 These were renamed for consistency. The old commands continue to work.
7888 `info handle' is a new alias for `info signals'.
7890 You can now define pre-command hooks, which attach arbitrary command
7891 scripts to any command. The commands in the hook will be executed
7892 prior to the user's command. You can also create a hook which will be
7893 executed whenever the program stops. See gdb.texinfo.
7897 We now deal with Cfront style name mangling, and can even extract type
7898 info from mangled symbols. GDB can automatically figure out which
7899 symbol mangling style your C++ compiler uses.
7901 Calling of methods and virtual functions has been improved as well.
7905 The crash that occurred when debugging Sun Ansi-C compiled binaries is
7906 fixed. This was due to mishandling of the extra N_SO stabs output
7909 We also finally got Ultrix 4.2 running in house, and fixed core file
7910 support, with help from a dozen people on the net.
7912 John M. Farrell discovered that the reason that single-stepping was so
7913 slow on all of the Mips based platforms (primarily SGI and DEC) was
7914 that we were trying to demangle and lookup a symbol used for internal
7915 purposes on every instruction that was being stepped through. Changing
7916 the name of that symbol so that it couldn't be mistaken for a C++
7917 mangled symbol sped things up a great deal.
7919 Rich Pixley sped up symbol lookups in general by getting much smarter
7920 about when C++ symbol mangling is necessary. This should make symbol
7921 completion (TAB on the command line) much faster. It's not as fast as
7922 we'd like, but it's significantly faster than gdb-4.6.
7926 A new user controllable variable 'call_scratch_address' can
7927 specify the location of a scratch area to be used when GDB
7928 calls a function in the target. This is necessary because the
7929 usual method of putting the scratch area on the stack does not work
7930 in systems that have separate instruction and data spaces.
7932 We integrated changes to support the 29k UDI (Universal Debugger
7933 Interface), but discovered at the last minute that we didn't have all
7934 of the appropriate copyright paperwork. We are working with AMD to
7935 resolve this, and hope to have it available soon.
7939 We have sped up the remote serial line protocol, especially for targets
7940 with lots of registers. It now supports a new `expedited status' ('T')
7941 message which can be used in place of the existing 'S' status message.
7942 This allows the remote stub to send only the registers that GDB
7943 needs to make a quick decision about single-stepping or conditional
7944 breakpoints, eliminating the need to fetch the entire register set for
7945 each instruction being stepped through.
7947 The GDB remote serial protocol now implements a write-through cache for
7948 registers, only re-reading the registers if the target has run.
7950 There is also a new remote serial stub for SPARC processors. You can
7951 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
7952 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
7953 processor with a serial port.
7957 Configure.in files have become much easier to read and modify. A new
7958 `table driven' format makes it more obvious what configurations are
7959 supported, and what files each one uses.
7963 There is a new opcodes library which will eventually contain all of the
7964 disassembly routines and opcode tables. At present, it only contains
7965 Sparc and Z8000 routines. This will allow the assembler, debugger, and
7966 disassembler (binutils/objdump) to share these routines.
7968 The libiberty library is now copylefted under the GNU Library General
7969 Public License. This allows more liberal use, and was done so libg++
7970 can use it. This makes no difference to GDB, since the Library License
7971 grants all the rights from the General Public License.
7975 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
7976 reference to the stabs symbol info used by the debugger. It is (as far
7977 as we know) the only published document on this fascinating topic. We
7978 encourage you to read it, compare it to the stabs information on your
7979 system, and send improvements on the document in general (to
7980 bug-gdb@prep.ai.mit.edu).
7982 And, of course, many bugs have been fixed.
7985 *** Changes in GDB-4.6:
7987 * Better support for C++ function names
7989 GDB now accepts as input the "demangled form" of C++ overloaded function
7990 names and member function names, and can do command completion on such names
7991 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
7992 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
7993 Make use of command completion, it is your friend.
7995 GDB also now accepts a variety of C++ mangled symbol formats. They are
7996 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
7997 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
7998 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
7999 for the list of formats.
8001 * G++ symbol mangling problem
8003 Recent versions of gcc have a bug in how they emit debugging information for
8004 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8005 directory) can be applied to gcc to fix the problem. Alternatively, if you
8006 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8007 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8008 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8011 * New 'maintenance' command
8013 All of the commands related to hacking GDB internals have been moved out of
8014 the main command set, and now live behind the 'maintenance' command. This
8015 can also be abbreviated as 'mt'. The following changes were made:
8017 dump-me -> maintenance dump-me
8018 info all-breakpoints -> maintenance info breakpoints
8019 printmsyms -> maintenance print msyms
8020 printobjfiles -> maintenance print objfiles
8021 printpsyms -> maintenance print psymbols
8022 printsyms -> maintenance print symbols
8024 The following commands are new:
8026 maintenance demangle Call internal GDB demangler routine to
8027 demangle a C++ link name and prints the result.
8028 maintenance print type Print a type chain for a given symbol
8030 * Change to .gdbinit file processing
8032 We now read the $HOME/.gdbinit file before processing the argv arguments
8033 (e.g. reading symbol files or core files). This allows global parameters to
8034 be set, which will apply during the symbol reading. The ./.gdbinit is still
8035 read after argv processing.
8037 * New hosts supported
8039 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8041 GNU/Linux support i386-unknown-linux or linux
8043 We are also including code to support the HP/PA running BSD and HPUX. This
8044 is almost guaranteed not to work, as we didn't have time to test or build it
8045 for this release. We are including it so that the more adventurous (or
8046 masochistic) of you can play with it. We also had major problems with the
8047 fact that the compiler that we got from HP doesn't support the -g option.
8050 * New targets supported
8052 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8054 * More smarts about finding #include files
8056 GDB now remembers the compilation directory for all include files, and for
8057 all files from which C is generated (like yacc and lex sources). This
8058 greatly improves GDB's ability to find yacc/lex sources, and include files,
8059 especially if you are debugging your program from a directory different from
8060 the one that contains your sources.
8062 We also fixed a bug which caused difficulty with listing and setting
8063 breakpoints in include files which contain C code. (In the past, you had to
8064 try twice in order to list an include file that you hadn't looked at before.)
8066 * Interesting infernals change
8068 GDB now deals with arbitrary numbers of sections, where the symbols for each
8069 section must be relocated relative to that section's landing place in the
8070 target's address space. This work was needed to support ELF with embedded
8071 stabs used by Solaris-2.0.
8073 * Bug fixes (of course!)
8075 There have been loads of fixes for the following things:
8076 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8077 i960, stabs, DOS(GO32), procfs, etc...
8079 See the ChangeLog for details.
8081 *** Changes in GDB-4.5:
8083 * New machines supported (host and target)
8085 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8087 SGI Irix-4.x mips-sgi-irix4 or iris4
8089 * New malloc package
8091 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8092 Mmalloc is capable of handling multiple heaps of memory. It is also
8093 capable of saving a heap to a file, and then mapping it back in later.
8094 This can be used to greatly speedup the startup of GDB by using a
8095 pre-parsed symbol table which lives in a mmalloc managed heap. For
8096 more details, please read mmalloc/mmalloc.texi.
8100 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8101 'help info proc' for details.
8103 * MIPS ecoff symbol table format
8105 The code that reads MIPS symbol table format is now supported on all hosts.
8106 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8109 * File name changes for MS-DOS
8111 Many files in the config directories have been renamed to make it easier to
8112 support GDB on MS-DOSe systems (which have very restrictive file name
8113 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8114 environment) is close to working but has some remaining problems. Note
8115 that debugging of DOS programs is not supported, due to limitations
8116 in the ``operating system'', but it can be used to host cross-debugging.
8118 * Cross byte order fixes
8120 Many fixes have been made to support cross debugging of Sparc and MIPS
8121 targets from hosts whose byte order differs.
8123 * New -mapped and -readnow options
8125 If memory-mapped files are available on your system through the 'mmap'
8126 system call, you can use the -mapped option on the `file' or
8127 `symbol-file' commands to cause GDB to write the symbols from your
8128 program into a reusable file. If the program you are debugging is
8129 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8130 Future GDB debugging sessions will notice the presence of this file,
8131 and will quickly map in symbol information from it, rather than reading
8132 the symbol table from the executable program. Using the '-mapped'
8133 option in a GDB `file' or `symbol-file' command has the same effect as
8134 starting GDB with the '-mapped' command-line option.
8136 You can cause GDB to read the entire symbol table immediately by using
8137 the '-readnow' option with any of the commands that load symbol table
8138 information (or on the GDB command line). This makes the command
8139 slower, but makes future operations faster.
8141 The -mapped and -readnow options are typically combined in order to
8142 build a `fred.syms' file that contains complete symbol information.
8143 A simple GDB invocation to do nothing but build a `.syms' file for future
8146 gdb -batch -nx -mapped -readnow programname
8148 The `.syms' file is specific to the host machine on which GDB is run.
8149 It holds an exact image of GDB's internal symbol table. It cannot be
8150 shared across multiple host platforms.
8152 * longjmp() handling
8154 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8155 siglongjmp() without losing control. This feature has not yet been ported to
8156 all systems. It currently works on many 386 platforms, all MIPS-based
8157 platforms (SGI, DECstation, etc), and Sun3/4.
8161 Preliminary work has been put in to support the new Solaris OS from Sun. At
8162 this time, it can control and debug processes, but it is not capable of
8167 As always, many many bug fixes. The major areas were with g++, and mipsread.
8168 People using the MIPS-based platforms should experience fewer mysterious
8169 crashes and trashed symbol tables.
8171 *** Changes in GDB-4.4:
8173 * New machines supported (host and target)
8175 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8177 BSD Reno on Vax vax-dec-bsd
8178 Ultrix on Vax vax-dec-ultrix
8180 * New machines supported (target)
8182 AMD 29000 embedded, using EBMON a29k-none-none
8186 GDB continues to improve its handling of C++. `References' work better.
8187 The demangler has also been improved, and now deals with symbols mangled as
8188 per the Annotated C++ Reference Guide.
8190 GDB also now handles `stabs' symbol information embedded in MIPS
8191 `ecoff' symbol tables. Since the ecoff format was not easily
8192 extensible to handle new languages such as C++, this appeared to be a
8193 good way to put C++ debugging info into MIPS binaries. This option
8194 will be supported in the GNU C compiler, version 2, when it is
8197 * New features for SVR4
8199 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8200 shared libraries. Debugging dynamically linked programs should present
8201 only minor differences from debugging statically linked programs.
8203 The `info proc' command will print out information about any process
8204 on an SVR4 system (including the one you are debugging). At the moment,
8205 it prints the address mappings of the process.
8207 If you bring up GDB on another SVR4 system, please send mail to
8208 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8210 * Better dynamic linking support in SunOS
8212 Reading symbols from shared libraries which contain debugging symbols
8213 now works properly. However, there remain issues such as automatic
8214 skipping of `transfer vector' code during function calls, which
8215 make it harder to debug code in a shared library, than to debug the
8216 same code linked statically.
8220 GDB is now using the latest `getopt' routines from the FSF. This
8221 version accepts the -- prefix for options with long names. GDB will
8222 continue to accept the old forms (-option and +option) as well.
8223 Various single letter abbreviations for options have been explicity
8224 added to the option table so that they won't get overshadowed in the
8225 future by other options that begin with the same letter.
8229 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8230 Many assorted bugs have been handled. Many more remain to be handled.
8231 See the various ChangeLog files (primarily in gdb and bfd) for details.
8234 *** Changes in GDB-4.3:
8236 * New machines supported (host and target)
8238 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8239 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8240 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8242 * Almost SCO Unix support
8244 We had hoped to support:
8245 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8246 (except for core file support), but we discovered very late in the release
8247 that it has problems with process groups that render gdb unusable. Sorry
8248 about that. I encourage people to fix it and post the fixes.
8250 * Preliminary ELF and DWARF support
8252 GDB can read ELF object files on System V Release 4, and can handle
8253 debugging records for C, in DWARF format, in ELF files. This support
8254 is preliminary. If you bring up GDB on another SVR4 system, please
8255 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8260 GDB now uses the latest `readline' library. One user-visible change
8261 is that two tabs will list possible command completions, which previously
8262 required typing M-? (meta-question mark, or ESC ?).
8266 The `stepi' bug that many of you noticed has been squashed.
8267 Many bugs in C++ have been handled. Many more remain to be handled.
8268 See the various ChangeLog files (primarily in gdb and bfd) for details.
8270 * State of the MIPS world (in case you wondered):
8272 GDB can understand the symbol tables emitted by the compilers
8273 supplied by most vendors of MIPS-based machines, including DEC. These
8274 symbol tables are in a format that essentially nobody else uses.
8276 Some versions of gcc come with an assembler post-processor called
8277 mips-tfile. This program is required if you want to do source-level
8278 debugging of gcc-compiled programs. I believe FSF does not ship
8279 mips-tfile with gcc version 1, but it will eventually come with gcc
8282 Debugging of g++ output remains a problem. g++ version 1.xx does not
8283 really support it at all. (If you're lucky, you should be able to get
8284 line numbers and stack traces to work, but no parameters or local
8285 variables.) With some work it should be possible to improve the
8288 When gcc version 2 is released, you will have somewhat better luck.
8289 However, even then you will get confusing results for inheritance and
8292 We will eventually provide full debugging of g++ output on
8293 DECstations. This will probably involve some kind of stabs-in-ecoff
8294 encapulation, but the details have not been worked out yet.
8297 *** Changes in GDB-4.2:
8299 * Improved configuration
8301 Only one copy of `configure' exists now, and it is not self-modifying.
8302 Porting BFD is simpler.
8306 The `step' and `next' commands now only stop at the first instruction
8307 of a source line. This prevents the multiple stops that used to occur
8308 in switch statements, for-loops, etc. `Step' continues to stop if a
8309 function that has debugging information is called within the line.
8313 Lots of small bugs fixed. More remain.
8315 * New host supported (not target)
8317 Intel 386 PC clone running Mach i386-none-mach
8320 *** Changes in GDB-4.1:
8322 * Multiple source language support
8324 GDB now has internal scaffolding to handle several source languages.
8325 It determines the type of each source file from its filename extension,
8326 and will switch expression parsing and number formatting to match the
8327 language of the function in the currently selected stack frame.
8328 You can also specifically set the language to be used, with
8329 `set language c' or `set language modula-2'.
8333 GDB now has preliminary support for the GNU Modula-2 compiler,
8334 currently under development at the State University of New York at
8335 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8336 continue through the fall of 1991 and into 1992.
8338 Other Modula-2 compilers are currently not supported, and attempting to
8339 debug programs compiled with them will likely result in an error as the
8340 symbol table is read. Feel free to work on it, though!
8342 There are hooks in GDB for strict type checking and range checking,
8343 in the `Modula-2 philosophy', but they do not currently work.
8347 GDB can now write to executable and core files (e.g. patch
8348 a variable's value). You must turn this switch on, specify
8349 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8350 by assigning a new value to a variable. Modifications take
8353 * Automatic SunOS shared library reading
8355 When you run your program, GDB automatically determines where its
8356 shared libraries (if any) have been loaded, and reads their symbols.
8357 The `share' command is no longer needed. This also works when
8358 examining core files.
8362 You can specify the number of lines that the `list' command shows.
8365 * New machines supported (host and target)
8367 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8368 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8369 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8371 * New hosts supported (not targets)
8373 IBM RT/PC: romp-ibm-aix or rtpc
8375 * New targets supported (not hosts)
8377 AMD 29000 embedded with COFF a29k-none-coff
8378 AMD 29000 embedded with a.out a29k-none-aout
8379 Ultracomputer remote kernel debug a29k-nyu-kern
8381 * New remote interfaces
8387 *** Changes in GDB-4.0:
8391 Wide output is wrapped at good places to make the output more readable.
8393 Gdb now supports cross-debugging from a host machine of one type to a
8394 target machine of another type. Communication with the target system
8395 is over serial lines. The ``target'' command handles connecting to the
8396 remote system; the ``load'' command will download a program into the
8397 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8398 also supports debugging of realtime processes running under VxWorks,
8399 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8400 stub on the target system.
8402 New CPUs supported include the AMD 29000 and Intel 960.
8404 GDB now reads object files and symbol tables via a ``binary file''
8405 library, which allows a single copy of GDB to debug programs of multiple
8406 object file types such as a.out and coff.
8408 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8409 refcard.dvi and refcard.ps are available to format it).
8412 * Control-Variable user interface simplified
8414 All variables that control the operation of the debugger can be set
8415 by the ``set'' command, and displayed by the ``show'' command.
8417 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8418 ``Show prompt'' produces the response:
8419 Gdb's prompt is new-gdb=>.
8421 What follows are the NEW set commands. The command ``help set'' will
8422 print a complete list of old and new set commands. ``help set FOO''
8423 will give a longer description of the variable FOO. ``show'' will show
8424 all of the variable descriptions and their current settings.
8426 confirm on/off: Enables warning questions for operations that are
8427 hard to recover from, e.g. rerunning the program while
8428 it is already running. Default is ON.
8430 editing on/off: Enables EMACS style command line editing
8431 of input. Previous lines can be recalled with
8432 control-P, the current line can be edited with control-B,
8433 you can search for commands with control-R, etc.
8436 history filename NAME: NAME is where the gdb command history
8437 will be stored. The default is .gdb_history,
8438 or the value of the environment variable
8441 history size N: The size, in commands, of the command history. The
8442 default is 256, or the value of the environment variable
8445 history save on/off: If this value is set to ON, the history file will
8446 be saved after exiting gdb. If set to OFF, the
8447 file will not be saved. The default is OFF.
8449 history expansion on/off: If this value is set to ON, then csh-like
8450 history expansion will be performed on
8451 command line input. The default is OFF.
8453 radix N: Sets the default radix for input and output. It can be set
8454 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8455 in the current radix, so "set radix 10" is always a no-op.
8457 height N: This integer value is the number of lines on a page. Default
8458 is 24, the current `stty rows'' setting, or the ``li#''
8459 setting from the termcap entry matching the environment
8462 width N: This integer value is the number of characters on a line.
8463 Default is 80, the current `stty cols'' setting, or the ``co#''
8464 setting from the termcap entry matching the environment
8467 Note: ``set screensize'' is obsolete. Use ``set height'' and
8468 ``set width'' instead.
8470 print address on/off: Print memory addresses in various command displays,
8471 such as stack traces and structure values. Gdb looks
8472 more ``symbolic'' if you turn this off; it looks more
8473 ``machine level'' with it on. Default is ON.
8475 print array on/off: Prettyprint arrays. New convenient format! Default
8478 print demangle on/off: Print C++ symbols in "source" form if on,
8481 print asm-demangle on/off: Same, for assembler level printouts
8484 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8487 * Support for Epoch Environment.
8489 The epoch environment is a version of Emacs v18 with windowing. One
8490 new command, ``inspect'', is identical to ``print'', except that if you
8491 are running in the epoch environment, the value is printed in its own
8495 * Support for Shared Libraries
8497 GDB can now debug programs and core files that use SunOS shared libraries.
8498 Symbols from a shared library cannot be referenced
8499 before the shared library has been linked with the program (this
8500 happens after you type ``run'' and before the function main() is entered).
8501 At any time after this linking (including when examining core files
8502 from dynamically linked programs), gdb reads the symbols from each
8503 shared library when you type the ``sharedlibrary'' command.
8504 It can be abbreviated ``share''.
8506 sharedlibrary REGEXP: Load shared object library symbols for files
8507 matching a unix regular expression. No argument
8508 indicates to load symbols for all shared libraries.
8510 info sharedlibrary: Status of loaded shared libraries.
8515 A watchpoint stops execution of a program whenever the value of an
8516 expression changes. Checking for this slows down execution
8517 tremendously whenever you are in the scope of the expression, but is
8518 quite useful for catching tough ``bit-spreader'' or pointer misuse
8519 problems. Some machines such as the 386 have hardware for doing this
8520 more quickly, and future versions of gdb will use this hardware.
8522 watch EXP: Set a watchpoint (breakpoint) for an expression.
8524 info watchpoints: Information about your watchpoints.
8526 delete N: Deletes watchpoint number N (same as breakpoints).
8527 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8528 enable N: Re-enables watchpoint number N (same as breakpoints).
8531 * C++ multiple inheritance
8533 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8536 * C++ exception handling
8538 Gdb now supports limited C++ exception handling. Besides the existing
8539 ability to breakpoint on an exception handler, gdb can breakpoint on
8540 the raising of an exception (before the stack is peeled back to the
8543 catch FOO: If there is a FOO exception handler in the dynamic scope,
8544 set a breakpoint to catch exceptions which may be raised there.
8545 Multiple exceptions (``catch foo bar baz'') may be caught.
8547 info catch: Lists all exceptions which may be caught in the
8548 current stack frame.
8551 * Minor command changes
8553 The command ``call func (arg, arg, ...)'' now acts like the print
8554 command, except it does not print or save a value if the function's result
8555 is void. This is similar to dbx usage.
8557 The ``up'' and ``down'' commands now always print the frame they end up
8558 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8559 frames without printing.
8561 * New directory command
8563 'dir' now adds directories to the FRONT of the source search path.
8564 The path starts off empty. Source files that contain debug information
8565 about the directory in which they were compiled can be found even
8566 with an empty path; Sun CC and GCC include this information. If GDB can't
8567 find your source file in the current directory, type "dir .".
8569 * Configuring GDB for compilation
8571 For normal use, type ``./configure host''. See README or gdb.texinfo
8574 GDB now handles cross debugging. If you are remotely debugging between
8575 two different machines, type ``./configure host -target=targ''.
8576 Host is the machine where GDB will run; targ is the machine
8577 where the program that you are debugging will run.