1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 12
6 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
7 reading memory tag data for AArch64 MTE from core files generated by
8 the gcore command or the Linux kernel.
10 When a process uses memory-mapped pages protected by memory tags (for
11 example, AArch64 MTE), this additional information will be recorded in
12 the core file in the event of a crash or if GDB generates a core file
13 from the current process state. GDB will show this additional information
14 automatically, or through one of the memory-tag subcommands.
16 * "info breakpoints" now displays enabled breakpoint locations of
17 disabled breakpoints as in the "y-" state. For example:
19 (gdb) info breakpoints
20 Num Type Disp Enb Address What
21 1 breakpoint keep n <MULTIPLE>
22 1.1 y- 0x00000000000011b6 in ...
23 1.2 y- 0x00000000000011c2 in ...
24 1.3 n 0x00000000000011ce in ...
26 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
27 aarch64 architectures.
29 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
31 * Remove support for building against Python 2, it is now only possible to
32 build GDB against Python 3.
34 * DBX mode has been removed.
36 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
37 emit to indicate where a breakpoint should be placed to break in a function
40 * Completion now also offers "NUMBER" for "set" commands that accept
41 a numeric argument and the "unlimited" keyword. For example:
48 (gdb) complete set width
52 * Disassembler styling using libopcodes. GDB now supports
53 disassembler styling using libopcodes. This is only available for
54 some targets (currently x86 and RISC-V). For unsupported targets
55 Python Pygments is still used. For supported targets, libopcodes
56 styling is used by default.
58 * The Windows native target now supports target async.
60 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
64 maintenance set ignore-prologue-end-flag on|off
65 maintenance show ignore-prologue-end-flag
66 This setting, which is off by default, controls whether GDB ignores the
67 PROLOGUE-END flag from the line-table when skipping prologue. This can be
68 used to force GDB to use prologue analyzers if the line-table is constructed
69 from erroneous debug information.
71 set print nibbles [on|off]
73 This controls whether the 'print/t' command will display binary values
74 in groups of four bits, known as "nibbles". The default is 'off'.
76 maintenance set libopcodes-styling on|off
77 maintenance show libopcodes-styling
78 These can be used to force off libopcodes based styling, the Python
79 Pygments styling will then be used instead.
81 set style disassembler comment
82 show style disassembler comment
83 set style disassembler immediate
84 show style disassembler immediate
85 set style disassembler mnemonic
86 show style disassembler mnemonic
87 set style disassembler register
88 show style disassembler register
89 set style disassembler address
90 show style disassembler address
91 set style disassembler symbol
92 show style disassembler symbol
93 For targets that support libopcodes based styling, these settings
94 control how various aspects of the disassembler output are styled.
95 The 'disassembler address' and 'disassembler symbol' styles are
96 aliases for the 'address' and 'function' styles respectively.
98 maintenance print frame-id [ LEVEL ]
99 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
100 not given, then print the frame-id for the currently selected frame.
104 document user-defined
105 It is now possible to document user-defined aliases.
106 When a user-defined alias is documented, the help and apropos commands
107 use the provided documentation instead of the documentation of the
109 Documenting a user-defined alias is particularly useful when the alias
110 is a set of nested 'with' commands to avoid showing the help of
111 the with command for an alias that will in fact launch the
112 last command given in the nested commands.
114 maintenance info line-table
115 Add a PROLOGUE-END column to the output which indicates that an
116 entry corresponds to an address where a breakpoint should be placed
117 to be at the first instruction past a function's prologue.
121 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
123 GNU/Linux/CSKY (gdbserver) csky*-*linux*
127 ** GDB will now reformat the doc string for gdb.Command and
128 gdb.Parameter sub-classes to remove unnecessary leading
129 whitespace from each line before using the string as the help
132 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
133 that formats ADDRESS as 'address <symbol+offset>', where symbol is
134 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
135 This is the same format that GDB uses when printing address, symbol,
136 and offset information from the disassembler.
138 ** New function gdb.current_language that returns the name of the
139 current language. Unlike gdb.parameter('language'), this will
142 ** New method gdb.Frame.language that returns the name of the
145 ** New Python API for wrapping GDB's disassembler:
147 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
148 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
149 ARCH is either None or a string containing a bfd architecture
150 name. DISASSEMBLER is registered as a disassembler for
151 architecture ARCH, or for all architectures if ARCH is None.
152 The previous disassembler registered for ARCH is returned, this
153 can be None if no previous disassembler was registered.
155 - gdb.disassembler.Disassembler is the class from which all
156 disassemblers should inherit. Its constructor takes a string,
157 a name for the disassembler, which is currently only used in
158 some debug output. Sub-classes should override the __call__
159 method to perform disassembly, invoking __call__ on this base
160 class will raise an exception.
162 - gdb.disassembler.DisassembleInfo is the class used to describe
163 a single disassembly request from GDB. An instance of this
164 class is passed to the __call__ method of
165 gdb.disassembler.Disassembler and has the following read-only
166 attributes: 'address', and 'architecture', as well as the
167 following method: 'read_memory'.
169 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
170 calls GDB's builtin disassembler on INFO, which is a
171 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
172 optional, its default value is None. If MEMORY_SOURCE is not
173 None then it must be an object that has a 'read_memory' method.
175 - gdb.disassembler.DisassemblerResult is a class that can be used
176 to wrap the result of a call to a Disassembler. It has
177 read-only attributes 'length' and 'string'.
179 ** gdb.Objfile now has an attribute named "is_file". This is True
180 if the objfile comes from a file, and False otherwise.
182 ** New function gdb.print_options that returns a dictionary of the
183 prevailing print options, in the form accepted by
184 gdb.Value.format_string.
186 ** gdb.Value.format_string now uses the format provided by 'print',
187 if it is called during a 'print' or other similar operation.
189 ** gdb.Value.format_string now accepts the 'summary' keyword. This
190 can be used to request a shorter representation of a value, the
191 way that 'set print frame-arguments scalars' does.
193 ** New Python type gdb.BreakpointLocation.
194 The new attribute 'locations' of gdb.Breakpoint returns a list of
195 gdb.BreakpointLocation objects specifying the locations where the
196 breakpoint is inserted into the debuggee.
198 ** The gdb.register_window_type method now restricts the set of
199 acceptable window names. The first character of a window's name
200 must start with a character in the set [a-zA-Z], every subsequent
201 character of a window's name must be in the set [-_.a-zA-Z0-9].
203 * New features in the GDB remote stub, GDBserver
205 ** GDBserver is now supported on LoongArch GNU/Linux.
207 ** GDBserver is now supported on CSKY GNU/Linux.
209 * LoongArch floating-point support
211 GDB now supports floating-point on LoongArch GNU/Linux.
213 *** Changes in GDB 12
215 * DBX mode is deprecated, and will be removed in GDB 13
217 * GDB 12 is the last release of GDB that will support building against
218 Python 2. From GDB 13, it will only be possible to build GDB itself
219 with Python 3 support.
221 * The disable-randomization setting now works on Windows.
223 * Improved C++ template support
225 GDB now treats functions/types involving C++ templates like it does function
226 overloads. Users may omit parameter lists to set breakpoints on families of
227 template functions, including types/functions composed of multiple template types:
229 (gdb) break template_func(template_1, int)
231 The above will set breakpoints at every function `template_func' where
232 the first function parameter is any template type named `template_1' and
233 the second function parameter is `int'.
235 TAB completion also gains similar improvements.
237 * The FreeBSD native target now supports async mode.
243 Enable or disable multithreaded symbol loading. This is enabled
244 by default, but passing --disable-threading or --enable-threading=no
245 to configure will disable it.
247 Disabling this can cause a performance penalty when there are a lot of
248 symbols to load, but is useful for debugging purposes.
252 maint set backtrace-on-fatal-signal on|off
253 maint show backtrace-on-fatal-signal
254 This setting is 'on' by default. When 'on' GDB will print a limited
255 backtrace to stderr in the situation where GDB terminates with a
256 fatal signal. This only supported on some platforms where the
257 backtrace and backtrace_symbols_fd functions are available.
259 set source open on|off
261 This setting, which is on by default, controls whether GDB will try
262 to open source code files. Switching this off will stop GDB trying
263 to open and read source code files, which can be useful if the files
264 are located over a slow network connection.
268 These are now deprecated aliases for "set max-value-size" and
269 "show max-value-size".
271 task apply [all | TASK-IDS...] [FLAG]... COMMAND
272 Like "thread apply", but applies COMMAND to Ada tasks.
275 Watchpoints can now be restricted to a specific Ada task.
277 maint set internal-error backtrace on|off
278 maint show internal-error backtrace
279 maint set internal-warning backtrace on|off
280 maint show internal-warning backtrace
281 GDB can now print a backtrace of itself when it encounters either an
282 internal-error, or an internal-warning. This is on by default for
283 internal-error and off by default for internal-warning.
286 Deprecated and replaced by "set logging enabled on|off".
288 set logging enabled on|off
290 These commands set or show whether logging is enabled or disabled.
293 You can now exit GDB by using the new command "exit", in addition to
294 the existing "quit" command.
296 set debug threads on|off
298 Print additional debug messages about thread creation and deletion.
300 set debug linux-nat on|off
302 These new commands replaced the old 'set debug lin-lwp' and 'show
303 debug lin-lwp' respectively. Turning this setting on prints debug
304 messages relating to GDB's handling of native Linux inferiors.
306 maint flush source-cache
307 Flush the contents of the source code cache.
309 maint set gnu-source-highlight enabled on|off
310 maint show gnu-source-highlight enabled
311 Whether GDB should use the GNU Source Highlight library for adding
312 styling to source code. When off, the library will not be used, even
313 when available. When GNU Source Highlight isn't used, or can't add
314 styling to a particular source file, then the Python Pygments
315 library will be used instead.
317 set suppress-cli-notifications (on|off)
318 show suppress-cli-notifications
319 This controls whether printing the notifications is suppressed for CLI.
320 CLI notifications occur when you change the selected context
321 (i.e., the current inferior, thread and/or the frame), or when
322 the program being debugged stops (e.g., because of hitting a
323 breakpoint, completing source-stepping, an interrupt, etc.).
325 set style disassembler enabled on|off
326 show style disassembler enabled
327 If GDB is compiled with Python support, and the Python Pygments
328 package is available, then, when this setting is on, disassembler
329 output will have styling applied.
331 set ada source-charset
332 show ada source-charset
333 Set the character set encoding that is assumed for Ada symbols. Valid
334 values for this follow the values that can be passed to the GNAT
335 compiler via the '-gnati' option. The default is ISO-8859-1.
341 These are the new names for the old 'layout', 'focus', 'refresh',
342 and 'winheight' tui commands respectively. The old names still
343 exist as aliases to these new commands.
347 The new command 'tui window width', and the alias 'winwidth' allow
348 the width of a tui window to be adjusted when windows are laid out
353 Control the display of debug output about GDB's tui.
358 Printing of floating-point values with base-modifying formats like
359 /x has been changed to display the underlying bytes of the value in
360 the desired base. This was GDB's documented behavior, but was never
361 implemented correctly.
364 This command can now print a reply, if the reply includes
365 non-printable characters. Any non-printable characters are printed
366 as escaped hex, e.g. \x?? where '??' is replaces with the value of
367 the non-printable character.
370 The clone-inferior command now ensures that the TTY, CMD and ARGS
371 settings are copied from the original inferior to the new one.
372 All modifications to the environment variables done using the 'set
373 environment' or 'unset environment' commands are also copied to the new
376 set debug lin-lwp on|off
378 These commands have been removed from GDB. The new command 'set
379 debug linux-nat' and 'show debug linux-nat' should be used
383 This command now includes information about the width of the tui
384 windows in its output.
390 These commands are now aliases for the 'tui layout', 'tui focus',
391 'tui refresh', and 'tui window height' commands respectively.
393 * GDB's Ada parser now supports an extension for specifying the exact
394 byte contents of a floating-point literal. This can be useful for
395 setting floating-point registers to a precise value without loss of
396 precision. The syntax is an extension of the based literal syntax.
397 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
398 of the floating-point type, and the "f" is the marker for floating
403 ** The '-add-inferior' with no option flags now inherits the
404 connection of the current inferior, this restores the behaviour of
405 GDB as it was prior to GDB 10.
407 ** The '-add-inferior' command now accepts a '--no-connection'
408 option, which causes the new inferior to start without a
411 ** The default version of the MI interpreter is now 4 (-i=mi4).
413 ** The "script" field in breakpoint output (which is syntactically
414 incorrect in MI 3 and below) has changed in MI 4 to become a list.
415 This affects the following commands and events:
419 - =breakpoint-created
420 - =breakpoint-modified
422 The -fix-breakpoint-script-output command can be used to enable
423 this behavior with previous MI versions.
427 GNU/Linux/LoongArch loongarch*-*-linux*
435 ** New function gdb.add_history(), which takes a gdb.Value object
436 and adds the value it represents to GDB's history list. An
437 integer, the index of the new item in the history list, is
440 ** New function gdb.history_count(), which returns the number of
441 values in GDB's value history.
443 ** New gdb.events.gdb_exiting event. This event is called with a
444 gdb.GdbExitingEvent object which has the read-only attribute
445 'exit_code', which contains the value of the GDB exit code. This
446 event is triggered once GDB decides it is going to exit, but
447 before GDB starts to clean up its internal state.
449 ** New function gdb.architecture_names(), which returns a list
450 containing all of the possible Architecture.name() values. Each
453 ** New function gdb.Architecture.integer_type(), which returns an
454 integer type given a size and a signed-ness.
456 ** New gdb.TargetConnection object type that represents a connection
457 (as displayed by the 'info connections' command). A sub-class,
458 gdb.RemoteTargetConnection, is used to represent 'remote' and
459 'extended-remote' connections.
461 ** The gdb.Inferior type now has a 'connection' property which is an
462 instance of gdb.TargetConnection, the connection used by this
463 inferior. This can be None if the inferior has no connection.
465 ** New 'gdb.events.connection_removed' event registry, which emits a
466 'gdb.ConnectionEvent' when a connection is removed from GDB.
467 This event has a 'connection' property, a gdb.TargetConnection
468 object for the connection being removed.
470 ** New gdb.connections() function that returns a list of all
471 currently active connections.
473 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
474 is equivalent to the existing 'maint packet' CLI command; it
475 allows a user specified packet to be sent to the remote target.
477 ** New function gdb.host_charset(), returns a string, which is the
478 name of the current host charset.
480 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
483 ** New gdb.with_parameter(NAME, VALUE). This returns a context
484 manager that temporarily sets the gdb parameter NAME to VALUE,
485 then resets it when the context is exited.
487 ** The gdb.Value.format_string method now takes a 'styling'
488 argument, which is a boolean. When true, the returned string can
489 include escape sequences to apply styling. The styling will only
490 be present if styling is otherwise turned on in GDB (see 'help
491 set styling'). When false, which is the default if the argument
492 is not given, then no styling is applied to the returned string.
494 ** New read-only attribute gdb.InferiorThread.details, which is
495 either a string, containing additional, target specific thread
496 state information, or None, if there is no such additional
499 ** New read-only attribute gdb.Type.is_scalar, which is True for
500 scalar types, and False for all other types.
502 ** New read-only attribute gdb.Type.is_signed. This attribute
503 should only be read when Type.is_scalar is True, and will be True
504 for signed types, and False for all other types. Attempting to
505 read this attribute for non-scalar types will raise a ValueError.
507 ** It is now possible to add GDB/MI commands implemented in Python.
509 * New features in the GDB remote stub, GDBserver
511 ** GDBserver is now supported on OpenRISC GNU/Linux.
513 * New native configurations
515 GNU/Linux/OpenRISC or1k*-*-linux*
517 *** Changes in GDB 11
519 * The 'set disassembler-options' command now supports specifying options
522 * GDB now supports general memory tagging functionality if the underlying
523 architecture supports the proper primitives and hooks. Currently this is
524 enabled only for AArch64 MTE.
528 - Additional information when the inferior crashes with a SIGSEGV caused by
529 a memory tag violation.
531 - A new modifier 'm' for the "x" command, which displays allocation tags for a
532 particular memory range.
534 - Display of memory tag mismatches by "print", for addresses and
535 pointers, if memory tagging is supported by the architecture.
537 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
542 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
544 The MI -break-insert and -dprintf-insert commands now support a
545 new "--qualified" option that makes GDB interpret a specified
546 function name as a complete fully-qualified name. This is the
547 equivalent of the CLI's "break -qualified" and "dprintf
550 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
552 The MI -break-insert and -dprintf-insert commands now support a
553 '--force-condition' flag to forcibly define a condition even when
554 the condition is invalid at all locations of the breakpoint. This
555 is equivalent to the '-force-condition' flag of the CLI's "break"
558 ** '-break-condition --force'
560 The MI -break-condition command now supports a '--force' flag to
561 forcibly define a condition even when the condition is invalid at
562 all locations of the selected breakpoint. This is equivalent to
563 the '-force' flag of the CLI's "cond" command.
565 ** '-file-list-exec-source-files [--group-by-objfile]
566 [--basename | --dirname]
569 The existing -file-list-exec-source-files command now takes an
570 optional REGEXP which is used to filter the source files that are
571 included in the results.
573 By default REGEXP is matched against the full filename of the
574 source file. When one of --basename or --dirname is given then
575 REGEXP is only matched against the specified part of the full
578 When the optional --group-by-objfile flag is used the output
579 format is changed, the results are now a list of object files
580 (executable and libraries) with the source files that are
581 associated with each object file.
583 The results from -file-list-exec-source-files now include a
584 'debug-fully-read' field which takes the value 'true' or 'false'.
585 A 'true' value indicates the source file is from a compilation
586 unit that has had its debug information fully read in by GDB, a
587 value of 'false' indicates GDB has only performed a partial scan
588 of the debug information so far.
590 * GDB now supports core file debugging for x86_64 Cygwin programs.
592 * GDB will now look for the .gdbinit file in a config directory before
593 looking for ~/.gdbinit. The file is searched for in the following
594 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
595 $HOME/.gdbinit. On Apple hosts the search order is instead:
596 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
598 * GDB now supports fixed point types which are described in DWARF
599 as base types with a fixed-point encoding. Additionally, support
600 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
603 For Ada, this allows support for fixed point types without requiring
604 the use of the GNAT encoding (based on information added to the type's
605 name following a GNAT-specific format).
607 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
608 or ~/.gdbearlyinit if these files are present. These files are
609 processed earlier than any of the other initialization files and
610 can affect parts of GDB's startup that previously had already been
611 completed before the initialization files were read, for example
612 styling of the initial GDB greeting.
614 * GDB now has two new options "--early-init-command" and
615 "--early-init-eval-command" with corresponding short options "-eix"
616 and "-eiex" that allow options (that would normally appear in a
617 gdbearlyinit file) to be passed on the command line.
619 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
620 now understood by GDB, and can be used to describe the vector
621 registers of a target. The precise requirements of this register
622 feature are documented in the GDB manual.
624 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
625 supported by GDB and describes a new VPR register from the ARM MVE
626 (Helium) extension. See the GDB manual for more information.
630 ** TUI windows now support mouse actions. The mouse wheel scrolls
631 the appropriate window.
633 ** Key combinations that do not have a specific action on the
634 focused window are passed to GDB. For example, you now can use
635 Ctrl-Left/Ctrl-Right to move between words in the command window
636 regardless of which window is in focus. Previously you would
637 need to focus on the command window for such key combinations to
643 show debug event-loop
644 Control the display of debug output about GDB's event loop.
646 set print memory-tag-violations
647 show print memory-tag-violations
648 Control whether to display additional information about memory tag violations
649 when printing pointers and addresses. Architecture support for memory
650 tagging is required for this option to have an effect.
652 maintenance flush symbol-cache
653 maintenance flush register-cache
654 These new commands are equivalent to the already existing commands
655 'maintenance flush-symbol-cache' and 'flushregs' respectively.
657 maintenance flush dcache
658 A new command to flush the dcache.
660 maintenance info target-sections
661 Print GDB's internal target sections table.
664 Print the JIT code objects in the inferior known to GDB.
666 memory-tag show-logical-tag POINTER
667 Print the logical tag for POINTER.
668 memory-tag with-logical-tag POINTER TAG
669 Print POINTER with logical tag TAG.
670 memory-tag show-allocation-tag ADDRESS
671 Print the allocation tag for ADDRESS.
672 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
673 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
674 memory-tag check POINTER
675 Validate that POINTER's logical tag matches the allocation tag.
677 set startup-quietly on|off
679 When 'on', this causes GDB to act as if "-silent" were passed on the
680 command line. This command needs to be added to an early
681 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
684 set print type hex on|off
686 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
687 and offsets of struct members. When 'off', decimal notation is used.
689 set python ignore-environment on|off
690 show python ignore-environment
691 When 'on', this causes GDB's builtin Python to ignore any
692 environment variables that would otherwise affect how Python
693 behaves. This command needs to be added to an early initialization
694 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
696 set python dont-write-bytecode auto|on|off
697 show python dont-write-bytecode
698 When 'on', this causes GDB's builtin Python to not write any
699 byte-code (.pyc files) to disk. This command needs to be added to
700 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
701 order to affect GDB. When 'off' byte-code will always be written.
702 When set to 'auto' (the default) Python will check the
703 PYTHONDONTWRITEBYTECODE environment variable.
707 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
708 [-force-condition] [if CONDITION]
709 This command would previously refuse setting a breakpoint if the
710 CONDITION expression is invalid at a location. It now accepts and
711 defines the breakpoint if there is at least one location at which
712 the CONDITION is valid. The locations for which the CONDITION is
713 invalid, are automatically disabled. If CONDITION is invalid at all
714 of the locations, setting the breakpoint is still rejected. However,
715 the '-force-condition' flag can be used in this case for forcing GDB to
716 define the breakpoint, making all the current locations automatically
717 disabled. This may be useful if the user knows the condition will
718 become meaningful at a future location, e.g. due to a shared library
721 condition [-force] N COND
722 The behavior of this command is changed the same way for the 'break'
723 command as explained above. The '-force' flag can be used to force
724 GDB into defining the condition even when COND is invalid for all the
725 current locations of breakpoint N.
728 maintenance flush-symbol-cache
729 These commands are deprecated in favor of the new commands
730 'maintenance flush register-cache' and 'maintenance flush
731 symbol-cache' respectively.
733 set style version foreground COLOR
734 set style version background COLOR
735 set style version intensity VALUE
736 Control the styling of GDB's version number text.
739 When the ID parameter is omitted, then this command prints information
740 about the current inferior. When the ID parameter is present, the
741 behavior of the command is unchanged and have the inferior ID become
742 the current inferior.
744 maintenance info sections
745 The ALLOBJ keyword has been replaced with an -all-objects command
746 line flag. It is now possible to filter which sections are printed
747 even when -all-objects is passed.
749 ptype[/FLAGS] TYPE | EXPRESSION
750 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
751 notation is used when printing sizes and offsets of struct members.
752 When '/d' is set, decimal notation is used when printing sizes and
753 offsets of struct members. Default behavior is given by 'show print
757 The info sources command output has been restructured. The results
758 are now based around a list of objfiles (executable and libraries),
759 and for each objfile the source files that are part of that objfile
762 * Removed targets and native configurations
764 ARM Symbian arm*-*-symbianelf*
769 Request the remote to send allocation tags for a particular memory range.
771 Request the remote to store the specified allocation tags to the requested
776 ** Improved support for rvalue reference values:
777 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
778 value-referenced-value procedure now handles rvalue reference
781 ** New procedures for obtaining value variants:
782 value-reference-value, value-rvalue-reference-value and
785 ** Temporary breakpoints can now be created with make-breakpoint and
786 tested for using breakpoint-temporary?.
790 ** Inferior objects now contain a read-only 'connection_num' attribute that
791 gives the connection number as seen in 'info connections' and
794 ** New method gdb.Frame.level() which returns the stack level of the
797 ** New method gdb.PendingFrame.level() which returns the stack level
800 ** When hitting a catchpoint, the Python API will now emit a
801 gdb.BreakpointEvent rather than a gdb.StopEvent. The
802 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
804 ** Python TUI windows can now receive mouse click events. If the
805 Window object implements the click method, it is called for each
806 mouse click event in this window.
808 *** Changes in GDB 10
810 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
811 and "org.gnu.gdb.arc.aux". The old names are still supported but
812 must be considered obsolete. They will be deprecated after some
815 * Help and apropos commands will now show the documentation of a
816 command only once, even if that command has one or more aliases.
817 These commands now show the command name, then all of its aliases,
818 and finally the description of the command.
820 * 'help aliases' now shows only the user defined aliases. GDB predefined
821 aliases are shown together with their aliased command.
823 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
824 debugging information as well as source code.
826 When built with debuginfod, GDB can automatically query debuginfod
827 servers for the separate debug files and source code of the executable
830 To build GDB with debuginfod, pass --with-debuginfod to configure (this
831 requires libdebuginfod, the debuginfod client library).
833 debuginfod is distributed with elfutils, starting with version 0.178.
835 You can get the latest version from https://sourceware.org/elfutils.
837 * Multi-target debugging support
839 GDB now supports debugging multiple target connections
840 simultaneously. For example, you can now have each inferior
841 connected to different remote servers running in different machines,
842 or have one inferior debugging a local native process, an inferior
843 debugging a core dump, etc.
845 This support is experimental and comes with some limitations -- you
846 can only resume multiple targets simultaneously if all targets
847 support non-stop mode, and all remote stubs or servers must support
848 the same set of remote protocol features exactly. See also "info
849 connections" and "add-inferior -no-connection" below, and "maint set
850 target-non-stop" in the user manual.
852 * New features in the GDB remote stub, GDBserver
854 ** GDBserver is now supported on ARC GNU/Linux.
856 ** GDBserver is now supported on RISC-V GNU/Linux.
858 ** GDBserver no longer supports these host triplets:
869 i[34567]86-*-mingw32ce*
871 * Debugging MS-Windows processes now sets $_exitsignal when the
872 inferior is terminated by a signal, instead of setting $_exitcode.
874 * Multithreaded symbol loading has now been enabled by default on systems
875 that support it (see entry for GDB 9, below), providing faster
876 performance for programs with many symbols.
878 * The $_siginfo convenience variable now also works on Windows targets,
879 and will display the EXCEPTION_RECORD of the last handled exception.
881 * TUI windows can now be arranged horizontally.
883 * The command history filename can now be set to the empty string
884 either using 'set history filename' or by setting 'GDBHISTFILE=' in
885 the environment. The effect of setting this filename to the empty
886 string is that GDB will not try to load any previous command
889 * On Windows targets, it is now possible to debug 32-bit programs with a
894 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
895 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
896 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
897 running process, this new option indicates whether to detect
898 a mismatch between the current executable file loaded by GDB and the
899 executable file used to start the process. If 'ask', the default,
900 display a warning and ask the user whether to load the process
901 executable file; if 'warn', just display a warning; if 'off', don't
902 attempt to detect a mismatch.
904 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
905 Define a new TUI layout, specifying its name and the windows that
908 maintenance print xml-tdesc [FILE]
909 Prints the current target description as an XML document. If the
910 optional FILE is provided (which is an XML target description) then
911 the target description is read from FILE into GDB, and then
914 maintenance print core-file-backed-mappings
915 Prints file-backed mappings loaded from a core file's note section.
916 Output is expected to be similar to that of "info proc mappings".
918 set debug fortran-array-slicing on|off
919 show debug fortran-array-slicing
920 Print debugging when taking slices of Fortran arrays.
922 set fortran repack-array-slices on|off
923 show fortran repack-array-slices
924 When taking slices from Fortran arrays and strings, if the slice is
925 non-contiguous within the original value then, when this option is
926 on, the new value will be repacked into a single contiguous value.
927 When this option is off, then the value returned will consist of a
928 descriptor that describes the slice within the memory of the
929 original parent value.
933 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
934 The alias command can now specify default args for an alias.
935 GDB automatically prepends the alias default args to the argument list
936 provided explicitly by the user.
937 For example, to have a backtrace with full details, you can define
939 'alias bt_ALL = backtrace -entry-values both -frame-arg all
940 -past-main -past-entry -full'.
941 Alias default arguments can also use a set of nested 'with' commands,
942 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
943 defines the alias pp10 that will pretty print a maximum of 10 elements
944 of the given expression (if the expression is an array).
948 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
954 ** gdb.register_window_type can be used to implement new TUI windows
957 ** Dynamic types can now be queried. gdb.Type has a new attribute,
958 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
959 field of a dynamic type may have None for its "bitpos" attribute
962 ** Commands written in Python can be in the "TUI" help class by
963 registering with the new constant gdb.COMMAND_TUI.
965 ** New method gdb.PendingFrame.architecture () to retrieve the
966 architecture of the pending frame.
968 ** New gdb.Architecture.registers method that returns a
969 gdb.RegisterDescriptorIterator object, an iterator that returns
970 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
971 way to query the registers available for an architecture.
973 ** New gdb.Architecture.register_groups method that returns a
974 gdb.RegisterGroupIterator object, an iterator that returns
975 gdb.RegisterGroup objects. The new RegisterGroup is a way to
976 discover the available register groups.
980 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
982 ** Procedures 'memory-port-read-buffer-size',
983 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
984 and 'set-memory-port-write-buffer-size!' are deprecated. When
985 using Guile 2.2 and later, users who need to control the size of
986 a memory port's internal buffer can use the 'setvbuf' procedure.
990 * 'thread-exited' event is now available in the annotations interface.
992 * New built-in convenience variables $_gdb_major and $_gdb_minor
993 provide the GDB version. They are handy for conditionally using
994 features available only in or since specific GDB versions, in
995 scripts that should work error-free with many different versions,
996 such as in system-wide init files.
998 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
999 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1000 of the GDB settings and the GDB maintenance settings. They are handy
1001 for changing the logic of user defined commands depending on the
1002 current GDB settings.
1004 * GDB now supports Thread Local Storage (TLS) variables on several
1005 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1006 architectures require kernel changes. TLS is not yet supported for
1007 amd64 and i386 process core dumps.
1009 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1010 addresses that required unmasking are shown in the backtrace with the
1013 * Two new convenience functions $_cimag and $_creal that extract the
1014 imaginary and real parts respectively from complex numbers.
1016 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1017 provide the exitcode or exit status of the shell commands launched by
1018 GDB commands such as "shell", "pipe" and "make".
1020 * The command define-prefix can now define user defined prefix commands.
1021 User defined commands can now be defined using these user defined prefix
1024 * Command names can now use the . character.
1026 * The RX port now supports XML target descriptions.
1028 * GDB now shows the Ada task names at more places, e.g. in task switching
1031 * GDB can now be compiled with Python 3 on Windows.
1033 * New convenience variable $_ada_exception holds the address of the
1034 Ada exception being thrown. This is set by Ada-related catchpoints.
1036 * GDB can now place breakpoints on nested functions and subroutines in
1037 Fortran code. The '::' operator can be used between parent and
1038 child scopes when placing breakpoints, for example:
1040 (gdb) break outer_function::inner_function
1042 The 'outer_function::' prefix is only needed if 'inner_function' is
1043 not visible in the current scope.
1045 * In addition to the system-wide gdbinit file, if configured with
1046 --with-system-gdbinit-dir, GDB will now also load files in that directory
1047 as system gdbinit files, unless the -nx or -n flag is provided. Files
1048 with extensions .gdb, .py and .scm are supported as long as GDB was
1049 compiled with support for that language.
1051 * GDB now supports multithreaded symbol loading for higher performance.
1052 This feature is still in testing, so it is disabled by default. You
1053 can turn it on using 'maint set worker-threads unlimited'.
1057 ** The gdb.Value type has a new method 'format_string' which returns a
1058 string representing the value. The formatting is controlled by the
1059 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1060 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1061 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1063 ** gdb.Type has a new property 'objfile' which returns the objfile the
1064 type was defined in.
1066 ** The frame information printed by the python frame filtering code
1067 is now consistent with what the 'backtrace' command prints when
1068 there are no filters, or when the 'backtrace' '-no-filters' option
1071 ** The new function gdb.lookup_static_symbol can be used to look up
1072 symbols with static linkage.
1074 ** The new function gdb.lookup_static_symbols can be used to look up
1075 all static symbols with static linkage.
1077 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1078 'lookup_static_symbol' to lookup a symbol from this objfile only.
1080 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1081 this block (e.g. block['local_variable']).
1085 | [COMMAND] | SHELL_COMMAND
1086 | -d DELIM COMMAND DELIM SHELL_COMMAND
1087 pipe [COMMAND] | SHELL_COMMAND
1088 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1089 Executes COMMAND and sends its output to SHELL_COMMAND.
1090 With no COMMAND, repeat the last executed command
1091 and send its output to SHELL_COMMAND.
1093 define-prefix COMMAND
1094 Define or mark a command as a user-defined prefix command.
1096 with SETTING [VALUE] [-- COMMAND]
1097 w SETTING [VALUE] [-- COMMAND]
1098 Temporarily set SETTING, run COMMAND, and restore SETTING.
1099 Usage: with SETTING -- COMMAND
1100 With no COMMAND, repeats the last executed command.
1101 SETTING is any GDB setting you can change with the "set"
1102 subcommands. For example, 'with language c -- print someobj'
1103 temporarily switches to the C language in order to print someobj.
1104 Settings can be combined: 'w lang c -- w print elements unlimited --
1105 usercmd' switches to the C language and runs usercmd with no limit
1106 of array elements to print.
1108 maint with SETTING [VALUE] [-- COMMAND]
1109 Like "with", but works with "maintenance set" settings.
1111 set may-call-functions [on|off]
1112 show may-call-functions
1113 This controls whether GDB will attempt to call functions in
1114 the program, such as with expressions in the print command. It
1115 defaults to on. Calling functions in the program being debugged
1116 can have undesired side effects. It is now possible to forbid
1117 such function calls. If function calls are forbidden, GDB will throw
1118 an error when a command (such as print expression) calls a function
1121 set print finish [on|off]
1123 This controls whether the `finish' command will display the value
1124 that is returned by the current function. When `off', the value is
1125 still entered into the value history, but it is not printed. The
1129 show print max-depth
1130 Allows deeply nested structures to be simplified when printing by
1131 replacing deeply nested parts (beyond the max-depth) with ellipses.
1132 The default max-depth is 20, but this can be set to unlimited to get
1133 the old behavior back.
1135 set print raw-values [on|off]
1136 show print raw-values
1137 By default, GDB applies the enabled pretty printers when printing a
1138 value. This allows to ignore the enabled pretty printers for a series
1139 of commands. The default is 'off'.
1141 set logging debugredirect [on|off]
1142 By default, GDB debug output will go to both the terminal and the logfile.
1143 Set if you want debug output to go only to the log file.
1145 set style title foreground COLOR
1146 set style title background COLOR
1147 set style title intensity VALUE
1148 Control the styling of titles.
1150 set style highlight foreground COLOR
1151 set style highlight background COLOR
1152 set style highlight intensity VALUE
1153 Control the styling of highlightings.
1155 maint set worker-threads
1156 maint show worker-threads
1157 Control the number of worker threads that can be used by GDB. The
1158 default is 0. "unlimited" lets GDB choose a number that is
1159 reasonable. Currently worker threads are only used when demangling
1160 the names of linker symbols.
1162 set style tui-border foreground COLOR
1163 set style tui-border background COLOR
1164 Control the styling of TUI borders.
1166 set style tui-active-border foreground COLOR
1167 set style tui-active-border background COLOR
1168 Control the styling of the active TUI border.
1170 maint set test-settings KIND
1171 maint show test-settings KIND
1172 A set of commands used by the testsuite for exercising the settings
1175 maint set tui-resize-message [on|off]
1176 maint show tui-resize-message
1177 Control whether GDB prints a message each time the terminal is
1178 resized when in TUI mode. This is primarily useful for testing the
1181 set print frame-info [short-location|location|location-and-address
1182 |source-and-location|source-line|auto]
1183 show print frame-info
1184 This controls what frame information is printed by the commands printing
1185 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1186 'frame', 'stepi'. The python frame filtering also respect this setting.
1187 The 'backtrace' '-frame-info' option can override this global setting.
1189 set tui compact-source
1190 show tui compact-source
1192 Enable the "compact" display mode for the TUI source window. The
1193 compact display uses only as much space as is needed for the line
1194 numbers in the current file, and only a single space to separate the
1195 line numbers from the source.
1197 info modules [-q] [REGEXP]
1198 Return a list of Fortran modules matching REGEXP, or all modules if
1201 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1202 Return a list of functions within all modules, grouped by module.
1203 The list of functions can be restricted with the optional regular
1204 expressions. MODULE_REGEXP matches against the module name,
1205 TYPE_REGEXP matches against the function type signature, and REGEXP
1206 matches against the function name.
1208 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1209 Return a list of variables within all modules, grouped by module.
1210 The list of variables can be restricted with the optional regular
1211 expressions. MODULE_REGEXP matches against the module name,
1212 TYPE_REGEXP matches against the variable type, and REGEXP matches
1213 against the variable name.
1215 set debug remote-packet-max-chars
1216 show debug remote-packet-max-chars
1217 Controls the number of characters to output in a remote packet when using
1219 The default is 512 bytes.
1222 Lists the target connections currently in use.
1227 The "help" command uses the title style to enhance the
1228 readibility of its output by styling the classes and
1232 Similarly to "help", the "apropos" command also uses the
1233 title style for the command names. "apropos" accepts now
1234 a flag "-v" (verbose) to show the full documentation
1235 of matching commands and to use the highlight style to mark
1236 the documentation parts matching REGEXP.
1240 The GDB printf and eval commands can now print C-style and Ada-style
1241 string convenience variables without calling functions in the program.
1242 This allows to do formatted printing of strings without having
1243 a running inferior, or when debugging a core dump.
1245 info sources [-dirname | -basename] [--] [REGEXP]
1246 This command has now optional arguments to only print the files
1247 whose names match REGEXP. The arguments -dirname and -basename
1248 allow to restrict matching respectively to the dirname and basename
1252 The "show style" and its subcommands are now styling
1253 a style name in their output using its own style, to help
1254 the user visualize the different styles.
1256 set print frame-arguments
1257 The new value 'presence' indicates to only indicate the presence of
1258 arguments using ..., instead of printing argument names and values.
1260 set print raw-frame-arguments
1261 show print raw-frame-arguments
1263 These commands replace the similarly-named "set/show print raw
1264 frame-arguments" commands (now with a dash instead of a space). The
1265 old commands are now deprecated and may be removed in a future
1268 add-inferior [-no-connection]
1269 The add-inferior command now supports a "-no-connection" flag that
1270 makes the new inferior start with no target connection associated.
1271 By default, the new inferior inherits the target connection of the
1272 current inferior. See also "info connections".
1275 This command's output now includes a new "Connection" column
1276 indicating which target connection an inferior is bound to. See
1277 "info connections" above.
1279 maint test-options require-delimiter
1280 maint test-options unknown-is-error
1281 maint test-options unknown-is-operand
1282 maint show test-options-completion-result
1283 Commands used by the testsuite to validate the command options
1286 focus, winheight, +, -, >, <
1287 These commands are now case-sensitive.
1289 * New command options, command completion
1291 GDB now has a standard infrastructure to support dash-style command
1292 options ('-OPT'). One benefit is that commands that use it can
1293 easily support completion of command line arguments. Try "CMD
1294 -[TAB]" or "help CMD" to find options supported by a command. Over
1295 time, we intend to migrate most commands to this infrastructure. A
1296 number of commands got support for new command options in this
1299 ** The "print" and "compile print" commands now support a number of
1300 options that allow overriding relevant global print settings as
1301 set by "set print" subcommands:
1305 -array-indexes [on|off]
1306 -elements NUMBER|unlimited
1310 -raw-values [on|off]
1311 -repeats NUMBER|unlimited
1312 -static-members [on|off]
1317 Note that because the "print"/"compile print" commands accept
1318 arbitrary expressions which may look like options (including
1319 abbreviations), if you specify any command option, then you must
1320 use a double dash ("--") to mark the end of argument processing.
1322 ** The "backtrace" command now supports a number of options that
1323 allow overriding relevant global print settings as set by "set
1324 backtrace" and "set print" subcommands:
1326 -entry-values no|only|preferred|if-needed|both|compact|default
1327 -frame-arguments all|scalars|none
1328 -raw-frame-arguments [on|off]
1329 -frame-info auto|source-line|location|source-and-location
1330 |location-and-address|short-location
1332 -past-entry [on|off]
1334 In addition, the full/no-filters/hide qualifiers are now also
1335 exposed as command options too:
1341 ** The "frame apply", "tfaas" and "faas" commands similarly now
1342 support the following options:
1345 -past-entry [on|off]
1347 ** The new "info sources" options -dirname and -basename options
1348 are using the standard '-OPT' infrastructure.
1350 All options above can also be abbreviated. The argument of boolean
1351 (on/off) options can be 0/1 too, and also the argument is assumed
1352 "on" if omitted. This allows writing compact command invocations,
1355 (gdb) p -ra -p -o 0 -- *myptr
1357 The above is equivalent to:
1359 (gdb) print -raw-values -pretty -object off -- *myptr
1361 ** The "info types" command now supports the '-q' flag to disable
1362 printing of some header information in a similar fashion to "info
1363 variables" and "info functions".
1365 ** The "info variables", "info functions", and "whereis" commands
1366 now take a '-n' flag that excludes non-debug symbols (symbols
1367 from the symbol table, not from the debug info such as DWARF)
1370 * Completion improvements
1372 ** GDB can now complete the options of the "thread apply all" and
1373 "taas" commands, and their "-ascending" option can now be
1376 ** GDB can now complete the options of the "info threads", "info
1377 functions", "info variables", "info locals", and "info args"
1380 ** GDB can now complete the options of the "compile file" and
1381 "compile code" commands. The "compile file" command now
1382 completes on filenames.
1384 ** GDB can now complete the backtrace command's
1385 "full/no-filters/hide" qualifiers.
1387 * In settings, you can now abbreviate "unlimited".
1389 E.g., "set print elements u" is now equivalent to "set print
1390 elements unlimited".
1395 This lists all the possible completions for the rest of the line, if it
1396 were to be given as a command itself. This is intended for use by MI
1397 frontends in cases when separate CLI and MI channels cannot be used.
1399 -catch-throw, -catch-rethrow, and -catch-catch
1400 These can be used to catch C++ exceptions in a similar fashion to
1401 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1403 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1404 These commands are the MI equivalent of the CLI commands 'info
1405 functions', 'info types', and 'info variables' respectively.
1407 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1410 -symbol-info-module-functions and -symbol-info-module-variables.
1411 These commands are the MI equivalent of the CLI commands 'info
1412 module functions' and 'info module variables'.
1416 ** The default version of the MI interpreter is now 3 (-i=mi3).
1418 ** The output of information about multi-location breakpoints (which is
1419 syntactically incorrect in MI 2) has changed in MI 3. This affects
1420 the following commands and events:
1424 - =breakpoint-created
1425 - =breakpoint-modified
1427 The -fix-multi-location-breakpoint-output command can be used to enable
1428 this behavior with previous MI versions.
1430 ** Backtraces and frames include a new optional field addr_flags which is
1431 given after the addr field. On AArch64 this contains PAC if the address
1432 has been masked in the frame. On all other targets the field is not
1437 The testsuite now creates the files gdb.cmd (containing the arguments
1438 used to launch GDB) and gdb.in (containing all the commands sent to
1439 GDB) in the output directory for each test script. Multiple invocations
1440 are appended with .1, .2, .3 etc.
1442 * Building GDB and GDBserver now requires GNU make >= 3.82.
1444 Using another implementation of the make program or an earlier version of
1445 GNU make to build GDB or GDBserver is not supported.
1447 * Building GDB now requires GNU readline >= 7.0.
1449 GDB now bundles GNU readline 8.0, but if you choose to use
1450 --with-system-readline, only readline >= 7.0 can be used.
1452 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1453 from .inputrc to bind keys in this keymap. This feature is only
1454 available when gdb is built against GNU readline 8.0 or later.
1456 * Removed targets and native configurations
1458 GDB no longer supports debugging the Cell Broadband Engine. This includes
1459 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1460 of Cell/B.E. applications that use both the PPU and SPU architectures.
1466 * Removed targets and native configurations
1468 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1469 sparc*-*-solaris2.10
1471 *** Changes in GDB 8.3
1473 * GDB and GDBserver now support access to additional registers on
1474 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1477 * GDB now has experimental support for the compilation and injection of
1478 C++ source code into the inferior. This beta release does not include
1479 support for several language features, such as templates, constructors,
1482 This feature requires GCC 7.1 or higher built with libcp1.so
1485 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1486 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1487 'ADDRESS:PORT' method.
1489 * DWARF index cache: GDB can now automatically save indices of DWARF
1490 symbols on disk to speed up further loading of the same binaries.
1492 * Ada task switching is now supported on aarch64-elf targets when
1493 debugging a program using the Ravenscar Profile. For more information,
1494 see the "Tasking Support when using the Ravenscar Profile" section
1495 in the GDB user manual.
1497 * GDB in batch mode now exits with status 1 if the last command to be
1500 * The RISC-V target now supports target descriptions.
1502 * System call catchpoints now support system call aliases on FreeBSD.
1503 When the ABI of a system call changes in FreeBSD, this is
1504 implemented by leaving a compatibility system call using the old ABI
1505 at the existing number and allocating a new system call number for
1506 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1507 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1508 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1509 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1510 so that a system call catchpoint for the 'kevent' system call will
1511 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1512 binaries. This ensures that 'kevent' system calls are caught for
1513 binaries using either the old or new ABIs.
1515 * Terminal styling is now available for the CLI and the TUI. GNU
1516 Source Highlight can additionally be used to provide styling of
1517 source code snippets. See the "set style" commands, below, for more
1520 * Removed support for old demangling styles arm, edg, gnu, hp and
1525 set debug compile-cplus-types
1526 show debug compile-cplus-types
1527 Control the display of debug output about type conversion in the
1528 C++ compile feature. Commands have no effect while compiling
1529 for other languages.
1533 Control whether debug output about files/functions skipping is
1536 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1537 Apply a command to some frames.
1538 FLAG arguments allow to control what output to produce and how to handle
1539 errors raised when applying COMMAND to a frame.
1542 Apply a command to all threads (ignoring errors and empty output).
1543 Shortcut for 'thread apply all -s COMMAND'.
1546 Apply a command to all frames (ignoring errors and empty output).
1547 Shortcut for 'frame apply all -s COMMAND'.
1550 Apply a command to all frames of all threads (ignoring errors and empty
1552 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1554 maint set dwarf unwinders (on|off)
1555 maint show dwarf unwinders
1556 Control whether DWARF unwinders can be used.
1559 Display a list of open files for a process.
1563 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1564 These commands all now take a frame specification which
1565 is either a frame level, or one of the keywords 'level', 'address',
1566 'function', or 'view' followed by a parameter. Selecting a frame by
1567 address, or viewing a frame outside the current backtrace now
1568 requires the use of a keyword. Selecting a frame by level is
1569 unchanged. The MI comment "-stack-select-frame" is unchanged.
1571 target remote FILENAME
1572 target extended-remote FILENAME
1573 If FILENAME is a Unix domain socket, GDB will attempt to connect
1574 to this socket instead of opening FILENAME as a character device.
1576 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1577 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1578 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1579 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1580 These commands can now print only the searched entities
1581 matching the provided regexp(s), giving a condition
1582 on the entity names or entity types. The flag -q disables
1583 printing headers or informations messages.
1589 These commands now determine the syntax for the shown entities
1590 according to the language chosen by `set language'. In particular,
1591 `set language auto' means to automatically choose the language of
1594 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1595 The 'thread apply' command accepts new FLAG arguments.
1596 FLAG arguments allow to control what output to produce and how to handle
1597 errors raised when applying COMMAND to a thread.
1599 set tui tab-width NCHARS
1600 show tui tab-width NCHARS
1601 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1603 set style enabled [on|off]
1605 Enable or disable terminal styling. Styling is enabled by default
1606 on most hosts, but disabled by default when in batch mode.
1608 set style sources [on|off]
1610 Enable or disable source code styling. Source code styling is
1611 enabled by default, but only takes effect if styling in general is
1612 enabled, and if GDB was linked with GNU Source Highlight.
1614 set style filename foreground COLOR
1615 set style filename background COLOR
1616 set style filename intensity VALUE
1617 Control the styling of file names.
1619 set style function foreground COLOR
1620 set style function background COLOR
1621 set style function intensity VALUE
1622 Control the styling of function names.
1624 set style variable foreground COLOR
1625 set style variable background COLOR
1626 set style variable intensity VALUE
1627 Control the styling of variable names.
1629 set style address foreground COLOR
1630 set style address background COLOR
1631 set style address intensity VALUE
1632 Control the styling of addresses.
1636 ** The '-data-disassemble' MI command now accepts an '-a' option to
1637 disassemble the whole function surrounding the given program
1638 counter value or function name. Support for this feature can be
1639 verified by using the "-list-features" command, which should
1640 contain "data-disassemble-a-option".
1642 ** Command responses and notifications that include a frame now include
1643 the frame's architecture in a new "arch" attribute.
1645 * New native configurations
1647 GNU/Linux/RISC-V riscv*-*-linux*
1648 FreeBSD/riscv riscv*-*-freebsd*
1652 GNU/Linux/RISC-V riscv*-*-linux*
1653 CSKY ELF csky*-*-elf
1654 CSKY GNU/LINUX csky*-*-linux
1655 FreeBSD/riscv riscv*-*-freebsd*
1657 GNU/Linux/OpenRISC or1k*-*-linux*
1661 GDB no longer supports native debugging on versions of MS-Windows
1666 ** GDB no longer supports Python versions less than 2.6.
1668 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1669 space associated to that inferior.
1671 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1672 of objfiles associated to that program space.
1674 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1675 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1678 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1679 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1680 correct and did not work properly.
1682 ** The gdb.Value type has a new constructor, which is used to construct a
1683 gdb.Value from a Python buffer object and a gdb.Type.
1689 Enable or disable the undefined behavior sanitizer. This is
1690 disabled by default, but passing --enable-ubsan=yes or
1691 --enable-ubsan=auto to configure will enable it. Enabling this can
1692 cause a performance penalty. The undefined behavior sanitizer was
1693 first introduced in GCC 4.9.
1695 *** Changes in GDB 8.2
1697 * The 'set disassembler-options' command now supports specifying options
1698 for the MIPS target.
1700 * The 'symbol-file' command now accepts an '-o' option to add a relative
1701 offset to all sections.
1703 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1704 a relative offset to all sections, but it allows to override the load
1705 address of individual sections using '-s'.
1707 * The 'add-symbol-file' command no longer requires the second argument
1708 (address of the text section).
1710 * The endianness used with the 'set endian auto' mode in the absence of
1711 an executable selected for debugging is now the last endianness chosen
1712 either by one of the 'set endian big' and 'set endian little' commands
1713 or by inferring from the last executable used, rather than the startup
1716 * The pager now allows a "c" response, meaning to disable the pager
1717 for the rest of the current command.
1719 * The commands 'info variables/functions/types' now show the source line
1720 numbers of symbol definitions when available.
1722 * 'info proc' now works on running processes on FreeBSD systems and core
1723 files created on FreeBSD systems.
1725 * C expressions can now use _Alignof, and C++ expressions can now use
1728 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1729 the vector length while the process is running.
1735 Control display of debugging info regarding the FreeBSD native target.
1737 set|show varsize-limit
1738 This new setting allows the user to control the maximum size of Ada
1739 objects being printed when those objects have a variable type,
1740 instead of that maximum size being hardcoded to 65536 bytes.
1742 set|show record btrace cpu
1743 Controls the processor to be used for enabling errata workarounds for
1744 branch trace decode.
1746 maint check libthread-db
1747 Run integrity checks on the current inferior's thread debugging
1750 maint set check-libthread-db (on|off)
1751 maint show check-libthread-db
1752 Control whether to run integrity checks on inferior specific thread
1753 debugging libraries as they are loaded. The default is not to
1754 perform such checks.
1758 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
1760 ** The commands attached to a breakpoint can be set by assigning to
1761 the breakpoint's "commands" field.
1763 ** gdb.execute can now execute multi-line gdb commands.
1765 ** The new functions gdb.convenience_variable and
1766 gdb.set_convenience_variable can be used to get and set the value
1767 of convenience variables.
1769 ** A gdb.Parameter will no longer print the "set" help text on an
1770 ordinary "set"; instead by default a "set" will be silent unless
1771 the get_set_string method returns a non-empty string.
1775 RiscV ELF riscv*-*-elf
1777 * Removed targets and native configurations
1779 m88k running OpenBSD m88*-*-openbsd*
1780 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
1781 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
1782 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
1784 * Aarch64/Linux hardware watchpoints improvements
1786 Hardware watchpoints on unaligned addresses are now properly
1787 supported when running Linux kernel 4.10 or higher: read and access
1788 watchpoints are no longer spuriously missed, and all watchpoints
1789 lengths between 1 and 8 bytes are supported. On older kernels,
1790 watchpoints set on unaligned addresses are no longer missed, with
1791 the tradeoff that there is a possibility of false hits being
1796 --enable-codesign=CERT
1797 This can be used to invoke "codesign -s CERT" after building gdb.
1798 This option is useful on macOS, where code signing is required for
1799 gdb to work properly.
1801 --disable-gdbcli has been removed
1802 This is now silently accepted, but does nothing.
1804 *** Changes in GDB 8.1
1806 * GDB now supports dynamically creating arbitrary register groups specified
1807 in XML target descriptions. This allows for finer grain grouping of
1808 registers on systems with a large amount of registers.
1810 * The 'ptype' command now accepts a '/o' flag, which prints the
1811 offsets and sizes of fields in a struct, like the pahole(1) tool.
1813 * New "--readnever" command line option instructs GDB to not read each
1814 symbol file's symbolic debug information. This makes startup faster
1815 but at the expense of not being able to perform symbolic debugging.
1816 This option is intended for use cases where symbolic debugging will
1817 not be used, e.g., when you only need to dump the debuggee's core.
1819 * GDB now uses the GNU MPFR library, if available, to emulate target
1820 floating-point arithmetic during expression evaluation when the target
1821 uses different floating-point formats than the host. At least version
1822 3.1 of GNU MPFR is required.
1824 * GDB now supports access to the guarded-storage-control registers and the
1825 software-based guarded-storage broadcast control registers on IBM z14.
1827 * On Unix systems, GDB now supports transmitting environment variables
1828 that are to be set or unset to GDBserver. These variables will
1829 affect the environment to be passed to the remote inferior.
1831 To inform GDB of environment variables that are to be transmitted to
1832 GDBserver, use the "set environment" command. Only user set
1833 environment variables are sent to GDBserver.
1835 To inform GDB of environment variables that are to be unset before
1836 the remote inferior is started by the GDBserver, use the "unset
1837 environment" command.
1839 * Completion improvements
1841 ** GDB can now complete function parameters in linespecs and
1842 explicit locations without quoting. When setting breakpoints,
1843 quoting around functions names to help with TAB-completion is
1844 generally no longer necessary. For example, this now completes
1847 (gdb) b function(in[TAB]
1848 (gdb) b function(int)
1850 Related, GDB is no longer confused with completing functions in
1851 C++ anonymous namespaces:
1854 (gdb) b (anonymous namespace)::[TAB][TAB]
1855 (anonymous namespace)::a_function()
1856 (anonymous namespace)::b_function()
1858 ** GDB now has much improved linespec and explicit locations TAB
1859 completion support, that better understands what you're
1860 completing and offers better suggestions. For example, GDB no
1861 longer offers data symbols as possible completions when you're
1862 setting a breakpoint.
1864 ** GDB now TAB-completes label symbol names.
1866 ** The "complete" command now mimics TAB completion accurately.
1868 * New command line options (gcore)
1871 Dump all memory mappings.
1873 * Breakpoints on C++ functions are now set on all scopes by default
1875 By default, breakpoints on functions/methods are now interpreted as
1876 specifying all functions with the given name ignoring missing
1877 leading scopes (namespaces and classes).
1879 For example, assuming a C++ program with symbols named:
1884 both commands "break func()" and "break B::func()" set a breakpoint
1887 You can use the new flag "-qualified" to override this. This makes
1888 GDB interpret the specified function name as a complete
1889 fully-qualified name instead. For example, using the same C++
1890 program, the "break -q B::func" command sets a breakpoint on
1891 "B::func", only. A parameter has been added to the Python
1892 gdb.Breakpoint constructor to achieve the same result when creating
1893 a breakpoint from Python.
1895 * Breakpoints on functions marked with C++ ABI tags
1897 GDB can now set breakpoints on functions marked with C++ ABI tags
1898 (e.g., [abi:cxx11]). See here for a description of ABI tags:
1899 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
1901 Functions with a C++11 abi tag are demangled/displayed like this:
1903 function[abi:cxx11](int)
1906 You can now set a breakpoint on such functions simply as if they had
1909 (gdb) b function(int)
1911 Or if you need to disambiguate between tags, like:
1913 (gdb) b function[abi:other_tag](int)
1915 Tab completion was adjusted accordingly as well.
1919 ** New events gdb.new_inferior, gdb.inferior_deleted, and
1920 gdb.new_thread are emitted. See the manual for further
1921 description of these.
1923 ** A new function, "gdb.rbreak" has been added to the Python API.
1924 This function allows the setting of a large number of breakpoints
1925 via a regex pattern in Python. See the manual for further details.
1927 ** Python breakpoints can now accept explicit locations. See the
1928 manual for a further description of this feature.
1931 * New features in the GDB remote stub, GDBserver
1933 ** GDBserver is now able to start inferior processes with a
1934 specified initial working directory.
1936 The user can set the desired working directory to be used from
1937 GDB using the new "set cwd" command.
1939 ** New "--selftest" command line option runs some GDBserver self
1940 tests. These self tests are disabled in releases.
1942 ** On Unix systems, GDBserver now does globbing expansion and variable
1943 substitution in inferior command line arguments.
1945 This is done by starting inferiors using a shell, like GDB does.
1946 See "set startup-with-shell" in the user manual for how to disable
1947 this from GDB when using "target extended-remote". When using
1948 "target remote", you can disable the startup with shell by using the
1949 new "--no-startup-with-shell" GDBserver command line option.
1951 ** On Unix systems, GDBserver now supports receiving environment
1952 variables that are to be set or unset from GDB. These variables
1953 will affect the environment to be passed to the inferior.
1955 * When catching an Ada exception raised with a message, GDB now prints
1956 the message in the catchpoint hit notification. In GDB/MI mode, that
1957 information is provided as an extra field named "exception-message"
1958 in the *stopped notification.
1960 * Trait objects can now be inspected When debugging Rust code. This
1961 requires compiler support which will appear in Rust 1.24.
1963 * New remote packets
1965 QEnvironmentHexEncoded
1966 Inform GDBserver of an environment variable that is to be passed to
1967 the inferior when starting it.
1970 Inform GDBserver of an environment variable that is to be unset
1971 before starting the remote inferior.
1974 Inform GDBserver that the environment should be reset (i.e.,
1975 user-set environment variables should be unset).
1978 Indicates whether the inferior must be started with a shell or not.
1981 Tell GDBserver that the inferior to be started should use a specific
1984 * The "maintenance print c-tdesc" command now takes an optional
1985 argument which is the file name of XML target description.
1987 * The "maintenance selftest" command now takes an optional argument to
1988 filter the tests to be run.
1990 * The "enable", and "disable" commands now accept a range of
1991 breakpoint locations, e.g. "enable 1.3-5".
1996 Set and show the current working directory for the inferior.
1998 set|show compile-gcc
1999 Set and show compilation command used for compiling and injecting code
2000 with the 'compile' commands.
2002 set debug separate-debug-file
2003 show debug separate-debug-file
2004 Control the display of debug output about separate debug file search.
2006 set dump-excluded-mappings
2007 show dump-excluded-mappings
2008 Control whether mappings marked with the VM_DONTDUMP flag should be
2009 dumped when generating a core file.
2011 maint info selftests
2012 List the registered selftests.
2015 Start the debugged program stopping at the first instruction.
2018 Control display of debugging messages related to OpenRISC targets.
2020 set|show print type nested-type-limit
2021 Set and show the limit of nesting level for nested types that the
2022 type printer will show.
2024 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2027 * Safer/improved support for debugging with no debug info
2029 GDB no longer assumes functions with no debug information return
2032 This means that GDB now refuses to call such functions unless you
2033 tell it the function's type, by either casting the call to the
2034 declared return type, or by casting the function to a function
2035 pointer of the right type, and calling that:
2037 (gdb) p getenv ("PATH")
2038 'getenv' has unknown return type; cast the call to its declared return type
2039 (gdb) p (char *) getenv ("PATH")
2040 $1 = 0x7fffffffe "/usr/local/bin:/"...
2041 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2042 $2 = 0x7fffffffe "/usr/local/bin:/"...
2044 Similarly, GDB no longer assumes that global variables with no debug
2045 info have type 'int', and refuses to print the variable's value
2046 unless you tell it the variable's type:
2049 'var' has unknown type; cast it to its declared type
2053 * New native configurations
2055 FreeBSD/aarch64 aarch64*-*-freebsd*
2056 FreeBSD/arm arm*-*-freebsd*
2060 FreeBSD/aarch64 aarch64*-*-freebsd*
2061 FreeBSD/arm arm*-*-freebsd*
2062 OpenRISC ELF or1k*-*-elf
2064 * Removed targets and native configurations
2066 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2068 *** Changes in GDB 8.0
2070 * GDB now supports access to the PKU register on GNU/Linux. The register is
2071 added by the Memory Protection Keys for Userspace feature which will be
2072 available in future Intel CPUs.
2074 * GDB now supports C++11 rvalue references.
2078 ** New functions to start, stop and access a running btrace recording.
2079 ** Rvalue references are now supported in gdb.Type.
2081 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2084 * Building GDB and GDBserver now requires a C++11 compiler.
2086 For example, GCC 4.8 or later.
2088 It is no longer possible to build GDB or GDBserver with a C
2089 compiler. The --disable-build-with-cxx configure option has been
2092 * Building GDB and GDBserver now requires GNU make >= 3.81.
2094 It is no longer supported to build GDB or GDBserver with another
2095 implementation of the make program or an earlier version of GNU make.
2097 * Native debugging on MS-Windows supports command-line redirection
2099 Command-line arguments used for starting programs on MS-Windows can
2100 now include redirection symbols supported by native Windows shells,
2101 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2102 as "run", "start", and "set args", as well as the corresponding MI
2105 * Support for thread names on MS-Windows.
2107 GDB now catches and handles the special exception that programs
2108 running on MS-Windows use to assign names to threads in the
2111 * Support for Java programs compiled with gcj has been removed.
2113 * User commands now accept an unlimited number of arguments.
2114 Previously, only up to 10 was accepted.
2116 * The "eval" command now expands user-defined command arguments.
2118 This makes it easier to process a variable number of arguments:
2123 eval "print $arg%d", $i
2128 * Target descriptions can now describe registers for sparc32 and sparc64.
2130 * GDB now supports DWARF version 5 (debug information format).
2131 Its .debug_names index is not yet supported.
2133 * New native configurations
2135 FreeBSD/mips mips*-*-freebsd
2139 Synopsys ARC arc*-*-elf32
2140 FreeBSD/mips mips*-*-freebsd
2142 * Removed targets and native configurations
2144 Alpha running FreeBSD alpha*-*-freebsd*
2145 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2150 Erases all the flash memory regions reported by the target.
2152 maint print arc arc-instruction address
2153 Print internal disassembler information about instruction at a given address.
2157 set disassembler-options
2158 show disassembler-options
2159 Controls the passing of target specific information to the disassembler.
2160 If it is necessary to specify more than one disassembler option then
2161 multiple options can be placed together into a comma separated list.
2162 The default value is the empty string. Currently, the only supported
2163 targets are ARM, PowerPC and S/390.
2168 Erases all the flash memory regions reported by the target. This is
2169 equivalent to the CLI command flash-erase.
2171 -file-list-shared-libraries
2172 List the shared libraries in the program. This is
2173 equivalent to the CLI command "info shared".
2176 Catchpoints stopping the program when Ada exceptions are
2177 handled. This is equivalent to the CLI command "catch handlers".
2179 *** Changes in GDB 7.12
2181 * GDB and GDBserver now build with a C++ compiler by default.
2183 The --enable-build-with-cxx configure option is now enabled by
2184 default. One must now explicitly configure with
2185 --disable-build-with-cxx in order to build with a C compiler. This
2186 option will be removed in a future release.
2188 * GDBserver now supports recording btrace without maintaining an active
2191 * GDB now supports a negative repeat count in the 'x' command to examine
2192 memory backward from the given address. For example:
2195 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2196 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2197 (gdb) x/-5i 0x0000000000400580
2198 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2199 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2200 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2201 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2202 0x40057b <main(int, char**)+25>:
2203 callq 0x400536 <Func1(int, char const*)>
2205 * Fortran: Support structures with fields of dynamic types and
2206 arrays of dynamic types.
2208 * The symbol dumping maintenance commands have new syntax.
2209 maint print symbols [-pc address] [--] [filename]
2210 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2211 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2212 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2213 maint print msymbols [-objfile objfile] [--] [filename]
2215 * GDB now supports multibit bitfields and enums in target register
2218 * New Python-based convenience function $_as_string(val), which returns
2219 the textual representation of a value. This function is especially
2220 useful to obtain the text label of an enum value.
2222 * Intel MPX bound violation handling.
2224 Segmentation faults caused by a Intel MPX boundary violation
2225 now display the kind of violation (upper or lower), the memory
2226 address accessed and the memory bounds, along with the usual
2227 signal received and code location.
2231 Program received signal SIGSEGV, Segmentation fault
2232 Upper bound violation while accessing address 0x7fffffffc3b3
2233 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2234 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2236 * Rust language support.
2237 GDB now supports debugging programs written in the Rust programming
2238 language. See https://www.rust-lang.org/ for more information about
2241 * Support for running interpreters on specified input/output devices
2243 GDB now supports a new mechanism that allows frontends to provide
2244 fully featured GDB console views, as a better alternative to
2245 building such views on top of the "-interpreter-exec console"
2246 command. See the new "new-ui" command below. With that command,
2247 frontends can now start GDB in the traditional command-line mode
2248 running in an embedded terminal emulator widget, and create a
2249 separate MI interpreter running on a specified i/o device. In this
2250 way, GDB handles line editing, history, tab completion, etc. in the
2251 console all by itself, and the GUI uses the separate MI interpreter
2252 for its own control and synchronization, invisible to the command
2255 * The "catch syscall" command catches groups of related syscalls.
2257 The "catch syscall" command now supports catching a group of related
2258 syscalls using the 'group:' or 'g:' prefix.
2263 skip -gfile file-glob-pattern
2264 skip -function function
2265 skip -rfunction regular-expression
2266 A generalized form of the skip command, with new support for
2267 glob-style file names and regular expressions for function names.
2268 Additionally, a file spec and a function spec may now be combined.
2270 maint info line-table REGEXP
2271 Display the contents of GDB's internal line table data structure.
2274 Run any GDB unit tests that were compiled in.
2277 Start a new user interface instance running INTERP as interpreter,
2278 using the TTY file for input/output.
2282 ** gdb.Breakpoint objects have a new attribute "pending", which
2283 indicates whether the breakpoint is pending.
2284 ** Three new breakpoint-related events have been added:
2285 gdb.breakpoint_created, gdb.breakpoint_modified, and
2286 gdb.breakpoint_deleted.
2288 signal-event EVENTID
2289 Signal ("set") the given MS-Windows event object. This is used in
2290 conjunction with the Windows JIT debugging (AeDebug) support, where
2291 the OS suspends a crashing process until a debugger can attach to
2292 it. Resuming the crashing process, in order to debug it, is done by
2293 signalling an event.
2295 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2296 was added in GDBserver, including JIT compiling fast tracepoint's
2297 conditional expression bytecode into native code.
2299 * Support for various remote target protocols and ROM monitors has
2302 target m32rsdi Remote M32R debugging over SDI
2303 target mips MIPS remote debugging protocol
2304 target pmon PMON ROM monitor
2305 target ddb NEC's DDB variant of PMON for Vr4300
2306 target rockhopper NEC RockHopper variant of PMON
2307 target lsi LSI variant of PMO
2309 * Support for tracepoints and fast tracepoints on powerpc-linux,
2310 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2311 including JIT compiling fast tracepoint's conditional expression
2312 bytecode into native code.
2314 * MI async record =record-started now includes the method and format used for
2315 recording. For example:
2317 =record-started,thread-group="i1",method="btrace",format="bts"
2319 * MI async record =thread-selected now includes the frame field. For example:
2321 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2325 Andes NDS32 nds32*-*-elf
2327 *** Changes in GDB 7.11
2329 * GDB now supports debugging kernel-based threads on FreeBSD.
2331 * Per-inferior thread numbers
2333 Thread numbers are now per inferior instead of global. If you're
2334 debugging multiple inferiors, GDB displays thread IDs using a
2335 qualified INF_NUM.THR_NUM form. For example:
2339 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2340 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2341 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2342 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2344 As consequence, thread numbers as visible in the $_thread
2345 convenience variable and in Python's InferiorThread.num attribute
2346 are no longer unique between inferiors.
2348 GDB now maintains a second thread ID per thread, referred to as the
2349 global thread ID, which is the new equivalent of thread numbers in
2350 previous releases. See also $_gthread below.
2352 For backwards compatibility, MI's thread IDs always refer to global
2355 * Commands that accept thread IDs now accept the qualified
2356 INF_NUM.THR_NUM form as well. For example:
2359 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2362 * In commands that accept a list of thread IDs, you can now refer to
2363 all threads of an inferior using a star wildcard. GDB accepts
2364 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2365 refer to all threads of the current inferior. For example, "info
2368 * You can use "info threads -gid" to display the global thread ID of
2371 * The new convenience variable $_gthread holds the global number of
2374 * The new convenience variable $_inferior holds the number of the
2377 * GDB now displays the ID and name of the thread that hit a breakpoint
2378 or received a signal, if your program is multi-threaded. For
2381 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2382 Thread 1 "main" received signal SIGINT, Interrupt.
2384 * Record btrace now supports non-stop mode.
2386 * Support for tracepoints on aarch64-linux was added in GDBserver.
2388 * The 'record instruction-history' command now indicates speculative execution
2389 when using the Intel Processor Trace recording format.
2391 * GDB now allows users to specify explicit locations, bypassing
2392 the linespec parser. This feature is also available to GDB/MI
2395 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2396 GDB now is able to debug both AArch64 applications and ARM applications
2399 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2400 including JIT compiling fast tracepoint's conditional expression bytecode
2403 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2405 * "info threads", "info inferiors", "info display", "info checkpoints"
2406 and "maint info program-spaces" now list the corresponding items in
2407 ascending ID order, for consistency with all other "info" commands.
2409 * In Ada, the overloads selection menu has been enhanced to display the
2410 parameter types and the return types for the matching overloaded subprograms.
2414 maint set target-non-stop (on|off|auto)
2415 maint show target-non-stop
2416 Control whether GDB targets always operate in non-stop mode even if
2417 "set non-stop" is "off". The default is "auto", meaning non-stop
2418 mode is enabled if supported by the target.
2420 maint set bfd-sharing
2421 maint show bfd-sharing
2422 Control the reuse of bfd objects.
2425 show debug bfd-cache
2426 Control display of debugging info regarding bfd caching.
2430 Control display of debugging info regarding FreeBSD threads.
2432 set remote multiprocess-extensions-packet
2433 show remote multiprocess-extensions-packet
2434 Set/show the use of the remote protocol multiprocess extensions.
2436 set remote thread-events
2437 show remote thread-events
2438 Set/show the use of thread create/exit events.
2440 set ada print-signatures on|off
2441 show ada print-signatures"
2442 Control whether parameter types and return types are displayed in overloads
2443 selection menus. It is activated (@code{on}) by default.
2447 Controls the maximum size of memory, in bytes, that GDB will
2448 allocate for value contents. Prevents incorrect programs from
2449 causing GDB to allocate overly large buffers. Default is 64k.
2451 * The "disassemble" command accepts a new modifier: /s.
2452 It prints mixed source+disassembly like /m with two differences:
2453 - disassembled instructions are now printed in program order, and
2454 - and source for all relevant files is now printed.
2455 The "/m" option is now considered deprecated: its "source-centric"
2456 output hasn't proved useful in practice.
2458 * The "record instruction-history" command accepts a new modifier: /s.
2459 It behaves exactly like /m and prints mixed source+disassembly.
2461 * The "set scheduler-locking" command supports a new mode "replay".
2462 It behaves like "off" in record mode and like "on" in replay mode.
2464 * Support for various ROM monitors has been removed:
2466 target dbug dBUG ROM monitor for Motorola ColdFire
2467 target picobug Motorola picobug monitor
2468 target dink32 DINK32 ROM monitor for PowerPC
2469 target m32r Renesas M32R/D ROM monitor
2470 target mon2000 mon2000 ROM monitor
2471 target ppcbug PPCBUG ROM monitor for PowerPC
2473 * Support for reading/writing memory and extracting values on architectures
2474 whose memory is addressable in units of any integral multiple of 8 bits.
2477 Allows to break when an Ada exception is handled.
2479 * New remote packets
2482 Indicates that an exec system call was executed.
2484 exec-events feature in qSupported
2485 The qSupported packet allows GDB to request support for exec
2486 events using the new 'gdbfeature' exec-event, and the qSupported
2487 response can contain the corresponding 'stubfeature'. Set and
2488 show commands can be used to display whether these features are enabled.
2491 Equivalent to interrupting with the ^C character, but works in
2494 thread created stop reason (T05 create:...)
2495 Indicates that the thread was just created and is stopped at entry.
2497 thread exit stop reply (w exitcode;tid)
2498 Indicates that the thread has terminated.
2501 Enables/disables thread create and exit event reporting. For
2502 example, this is used in non-stop mode when GDB stops a set of
2503 threads and synchronously waits for the their corresponding stop
2504 replies. Without exit events, if one of the threads exits, GDB
2505 would hang forever not knowing that it should no longer expect a
2506 stop for that same thread.
2509 Indicates that there are no resumed threads left in the target (all
2510 threads are stopped). The remote stub reports support for this stop
2511 reply to GDB's qSupported query.
2514 Enables/disables catching syscalls from the inferior process.
2515 The remote stub reports support for this packet to GDB's qSupported query.
2517 syscall_entry stop reason
2518 Indicates that a syscall was just called.
2520 syscall_return stop reason
2521 Indicates that a syscall just returned.
2523 * Extended-remote exec events
2525 ** GDB now has support for exec events on extended-remote Linux targets.
2526 For such targets with Linux kernels 2.5.46 and later, this enables
2527 follow-exec-mode and exec catchpoints.
2529 set remote exec-event-feature-packet
2530 show remote exec-event-feature-packet
2531 Set/show the use of the remote exec event feature.
2533 * Thread names in remote protocol
2535 The reply to qXfer:threads:read may now include a name attribute for each
2538 * Target remote mode fork and exec events
2540 ** GDB now has support for fork and exec events on target remote mode
2541 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2542 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2543 fork and exec catchpoints.
2545 * Remote syscall events
2547 ** GDB now has support for catch syscall on remote Linux targets,
2548 currently enabled on x86/x86_64 architectures.
2550 set remote catch-syscall-packet
2551 show remote catch-syscall-packet
2552 Set/show the use of the remote catch syscall feature.
2556 ** The -var-set-format command now accepts the zero-hexadecimal
2557 format. It outputs data in hexadecimal format with zero-padding on the
2562 ** gdb.InferiorThread objects have a new attribute "global_num",
2563 which refers to the thread's global thread ID. The existing
2564 "num" attribute now refers to the thread's per-inferior number.
2565 See "Per-inferior thread numbers" above.
2566 ** gdb.InferiorThread objects have a new attribute "inferior", which
2567 is the Inferior object the thread belongs to.
2569 *** Changes in GDB 7.10
2571 * Support for process record-replay and reverse debugging on aarch64*-linux*
2572 targets has been added. GDB now supports recording of A64 instruction set
2573 including advance SIMD instructions.
2575 * Support for Sun's version of the "stabs" debug file format has been removed.
2577 * GDB now honors the content of the file /proc/PID/coredump_filter
2578 (PID is the process ID) on GNU/Linux systems. This file can be used
2579 to specify the types of memory mappings that will be included in a
2580 corefile. For more information, please refer to the manual page of
2581 "core(5)". GDB also has a new command: "set use-coredump-filter
2582 on|off". It allows to set whether GDB will read the content of the
2583 /proc/PID/coredump_filter file when generating a corefile.
2585 * The "info os" command on GNU/Linux can now display information on
2587 "info os cpus" Listing of all cpus/cores on the system
2589 * GDB has two new commands: "set serial parity odd|even|none" and
2590 "show serial parity". These allows to set or show parity for the
2593 * The "info source" command now displays the producer string if it was
2594 present in the debug info. This typically includes the compiler version
2595 and may include things like its command line arguments.
2597 * The "info dll", an alias of the "info sharedlibrary" command,
2598 is now available on all platforms.
2600 * Directory names supplied to the "set sysroot" commands may be
2601 prefixed with "target:" to tell GDB to access shared libraries from
2602 the target system, be it local or remote. This replaces the prefix
2603 "remote:". The default sysroot has been changed from "" to
2604 "target:". "remote:" is automatically converted to "target:" for
2605 backward compatibility.
2607 * The system root specified by "set sysroot" will be prepended to the
2608 filename of the main executable (if reported to GDB as absolute by
2609 the operating system) when starting processes remotely, and when
2610 attaching to already-running local or remote processes.
2612 * GDB now supports automatic location and retrieval of executable
2613 files from remote targets. Remote debugging can now be initiated
2614 using only a "target remote" or "target extended-remote" command
2615 (no "set sysroot" or "file" commands are required). See "New remote
2618 * The "dump" command now supports verilog hex format.
2620 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2622 * On GNU/Linux, GDB and gdbserver are now able to access executable
2623 and shared library files without a "set sysroot" command when
2624 attaching to processes running in different mount namespaces from
2625 the debugger. This makes it possible to attach to processes in
2626 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2627 See "New remote packets" below.
2629 * The "tui reg" command now provides completion for all of the
2630 available register groups, including target specific groups.
2632 * The HISTSIZE environment variable is no longer read when determining
2633 the size of GDB's command history. GDB now instead reads the dedicated
2634 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2635 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2640 ** Memory ports can now be unbuffered.
2644 ** gdb.Objfile objects have a new attribute "username",
2645 which is the name of the objfile as specified by the user,
2646 without, for example, resolving symlinks.
2647 ** You can now write frame unwinders in Python.
2648 ** gdb.Type objects have a new method "optimized_out",
2649 returning optimized out gdb.Value instance of this type.
2650 ** gdb.Value objects have new methods "reference_value" and
2651 "const_value" which return a reference to the value and a
2652 "const" version of the value respectively.
2656 maint print symbol-cache
2657 Print the contents of the symbol cache.
2659 maint print symbol-cache-statistics
2660 Print statistics of symbol cache usage.
2662 maint flush-symbol-cache
2663 Flush the contents of the symbol cache.
2667 Start branch trace recording using Branch Trace Store (BTS) format.
2670 Evaluate expression by using the compiler and print result.
2674 Explicit commands for enabling and disabling tui mode.
2677 set mpx bound on i386 and amd64
2678 Support for bound table investigation on Intel MPX enabled applications.
2682 Start branch trace recording using Intel Processor Trace format.
2685 Print information about branch tracing internals.
2687 maint btrace packet-history
2688 Print the raw branch tracing data.
2690 maint btrace clear-packet-history
2691 Discard the stored raw branch tracing data.
2694 Discard all branch tracing data. It will be fetched and processed
2695 anew by the next "record" command.
2700 Renamed from "set debug dwarf2-die".
2701 show debug dwarf-die
2702 Renamed from "show debug dwarf2-die".
2704 set debug dwarf-read
2705 Renamed from "set debug dwarf2-read".
2706 show debug dwarf-read
2707 Renamed from "show debug dwarf2-read".
2709 maint set dwarf always-disassemble
2710 Renamed from "maint set dwarf2 always-disassemble".
2711 maint show dwarf always-disassemble
2712 Renamed from "maint show dwarf2 always-disassemble".
2714 maint set dwarf max-cache-age
2715 Renamed from "maint set dwarf2 max-cache-age".
2716 maint show dwarf max-cache-age
2717 Renamed from "maint show dwarf2 max-cache-age".
2719 set debug dwarf-line
2720 show debug dwarf-line
2721 Control display of debugging info regarding DWARF line processing.
2724 show max-completions
2725 Set the maximum number of candidates to be considered during
2726 completion. The default value is 200. This limit allows GDB
2727 to avoid generating large completion lists, the computation of
2728 which can cause the debugger to become temporarily unresponsive.
2730 set history remove-duplicates
2731 show history remove-duplicates
2732 Control the removal of duplicate history entries.
2734 maint set symbol-cache-size
2735 maint show symbol-cache-size
2736 Control the size of the symbol cache.
2738 set|show record btrace bts buffer-size
2739 Set and show the size of the ring buffer used for branch tracing in
2741 The obtained size may differ from the requested size. Use "info
2742 record" to see the obtained buffer size.
2744 set debug linux-namespaces
2745 show debug linux-namespaces
2746 Control display of debugging info regarding Linux namespaces.
2748 set|show record btrace pt buffer-size
2749 Set and show the size of the ring buffer used for branch tracing in
2750 Intel Processor Trace format.
2751 The obtained size may differ from the requested size. Use "info
2752 record" to see the obtained buffer size.
2754 maint set|show btrace pt skip-pad
2755 Set and show whether PAD packets are skipped when computing the
2758 * The command 'thread apply all' can now support new option '-ascending'
2759 to call its specified command for all threads in ascending order.
2761 * Python/Guile scripting
2763 ** GDB now supports auto-loading of Python/Guile scripts contained in the
2764 special section named `.debug_gdb_scripts'.
2766 * New remote packets
2768 qXfer:btrace-conf:read
2769 Return the branch trace configuration for the current thread.
2771 Qbtrace-conf:bts:size
2772 Set the requested ring buffer size for branch tracing in BTS format.
2775 Enable Intel Processor Trace-based branch tracing for the current
2776 process. The remote stub reports support for this packet to GDB's
2779 Qbtrace-conf:pt:size
2780 Set the requested ring buffer size for branch tracing in Intel Processor
2784 Indicates a memory breakpoint instruction was executed, irrespective
2785 of whether it was GDB that planted the breakpoint or the breakpoint
2786 is hardcoded in the program. This is required for correct non-stop
2790 Indicates the target stopped for a hardware breakpoint. This is
2791 required for correct non-stop mode operation.
2794 Return information about files on the remote system.
2796 qXfer:exec-file:read
2797 Return the full absolute name of the file that was executed to
2798 create a process running on the remote system.
2801 Select the filesystem on which vFile: operations with filename
2802 arguments will operate. This is required for GDB to be able to
2803 access files on remote targets where the remote stub does not
2804 share a common filesystem with the inferior(s).
2807 Indicates that a fork system call was executed.
2810 Indicates that a vfork system call was executed.
2812 vforkdone stop reason
2813 Indicates that a vfork child of the specified process has executed
2814 an exec or exit, allowing the vfork parent to resume execution.
2816 fork-events and vfork-events features in qSupported
2817 The qSupported packet allows GDB to request support for fork and
2818 vfork events using new 'gdbfeatures' fork-events and vfork-events,
2819 and the qSupported response can contain the corresponding
2820 'stubfeatures'. Set and show commands can be used to display
2821 whether these features are enabled.
2823 * Extended-remote fork events
2825 ** GDB now has support for fork events on extended-remote Linux
2826 targets. For targets with Linux kernels 2.5.60 and later, this
2827 enables follow-fork-mode and detach-on-fork for both fork and
2828 vfork, as well as fork and vfork catchpoints.
2830 * The info record command now shows the recording format and the
2831 branch tracing configuration for the current thread when using
2832 the btrace record target.
2833 For the BTS format, it shows the ring buffer size.
2835 * GDB now has support for DTrace USDT (Userland Static Defined
2836 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
2838 * GDB now supports access to vector registers on S/390 GNU/Linux
2841 * Removed command line options
2843 -xdb HP-UX XDB compatibility mode.
2845 * Removed targets and native configurations
2847 HP/PA running HP-UX hppa*-*-hpux*
2848 Itanium running HP-UX ia64-*-hpux*
2850 * New configure options
2853 This configure option allows the user to build GDB with support for
2854 Intel Processor Trace (default: auto). This requires libipt.
2856 --with-libipt-prefix=PATH
2857 Specify the path to the version of libipt that GDB should use.
2858 $PATH/include should contain the intel-pt.h header and
2859 $PATH/lib should contain the libipt.so library.
2861 *** Changes in GDB 7.9.1
2865 ** Xmethods can now specify a result type.
2867 *** Changes in GDB 7.9
2869 * GDB now supports hardware watchpoints on x86 GNU Hurd.
2873 ** You can now access frame registers from Python scripts.
2874 ** New attribute 'producer' for gdb.Symtab objects.
2875 ** gdb.Objfile objects have a new attribute "progspace",
2876 which is the gdb.Progspace object of the containing program space.
2877 ** gdb.Objfile objects have a new attribute "owner".
2878 ** gdb.Objfile objects have a new attribute "build_id",
2879 which is the build ID generated when the file was built.
2880 ** gdb.Objfile objects have a new method "add_separate_debug_file".
2881 ** A new event "gdb.clear_objfiles" has been added, triggered when
2882 selecting a new file to debug.
2883 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
2884 ** New function gdb.lookup_objfile.
2886 New events which are triggered when GDB modifies the state of the
2889 ** gdb.events.inferior_call_pre: Function call is about to be made.
2890 ** gdb.events.inferior_call_post: Function call has just been made.
2891 ** gdb.events.memory_changed: A memory location has been altered.
2892 ** gdb.events.register_changed: A register has been altered.
2894 * New Python-based convenience functions:
2896 ** $_caller_is(name [, number_of_frames])
2897 ** $_caller_matches(regexp [, number_of_frames])
2898 ** $_any_caller_is(name [, number_of_frames])
2899 ** $_any_caller_matches(regexp [, number_of_frames])
2901 * GDB now supports the compilation and injection of source code into
2902 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
2903 to compile the source code to object code, and if successful, inject
2904 and execute that code within the current context of the inferior.
2905 Currently the C language is supported. The commands used to
2906 interface with this new feature are:
2908 compile code [-raw|-r] [--] [source code]
2909 compile file [-raw|-r] filename
2913 demangle [-l language] [--] name
2914 Demangle "name" in the specified language, or the current language
2915 if elided. This command is renamed from the "maint demangle" command.
2916 The latter is kept as a no-op to avoid "maint demangle" being interpreted
2917 as "maint demangler-warning".
2919 queue-signal signal-name-or-number
2920 Queue a signal to be delivered to the thread when it is resumed.
2922 add-auto-load-scripts-directory directory
2923 Add entries to the list of directories from which to load auto-loaded
2926 maint print user-registers
2927 List all currently available "user" registers.
2929 compile code [-r|-raw] [--] [source code]
2930 Compile, inject, and execute in the inferior the executable object
2931 code produced by compiling the provided source code.
2933 compile file [-r|-raw] filename
2934 Compile and inject into the inferior the executable object code
2935 produced by compiling the source code stored in the filename
2938 * On resume, GDB now always passes the signal the program had stopped
2939 for to the thread the signal was sent to, even if the user changed
2940 threads before resuming. Previously GDB would often (but not
2941 always) deliver the signal to the thread that happens to be current
2944 * Conversely, the "signal" command now consistently delivers the
2945 requested signal to the current thread. GDB now asks for
2946 confirmation if the program had stopped for a signal and the user
2947 switched threads meanwhile.
2949 * "breakpoint always-inserted" modes "off" and "auto" merged.
2951 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
2952 won't remove breakpoints from the target until all threads stop,
2953 even in non-stop mode. The "auto" mode has been removed, and "off"
2954 is now the default mode.
2958 set debug symbol-lookup
2959 show debug symbol-lookup
2960 Control display of debugging info regarding symbol lookup.
2964 ** The -list-thread-groups command outputs an exit-code field for
2965 inferiors that have exited.
2969 MIPS SDE mips*-sde*-elf*
2973 Support for these obsolete configurations has been removed.
2975 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
2976 SGI Irix-5.x mips-*-irix5*
2977 SGI Irix-6.x mips-*-irix6*
2978 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
2979 VAX running Ultrix vax-*-ultrix*
2981 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
2982 and "assf"), have been removed. Use the "sharedlibrary" command, or
2983 its alias "share", instead.
2985 *** Changes in GDB 7.8
2987 * New command line options
2990 This is an alias for the --data-directory option.
2992 * GDB supports printing and modifying of variable length automatic arrays
2993 as specified in ISO C99.
2995 * The ARM simulator now supports instruction level tracing
2996 with or without disassembly.
3000 GDB now has support for scripting using Guile. Whether this is
3001 available is determined at configure time.
3002 Guile version 2.0 or greater is required.
3003 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3005 * New commands (for set/show, see "New options" below)
3009 Invoke CODE by passing it to the Guile interpreter.
3013 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3015 info auto-load guile-scripts [regexp]
3016 Print the list of automatically loaded Guile scripts.
3018 * The source command is now capable of sourcing Guile scripts.
3019 This feature is dependent on the debugger being built with Guile support.
3023 set print symbol-loading (off|brief|full)
3024 show print symbol-loading
3025 Control whether to print informational messages when loading symbol
3026 information for a file. The default is "full", but when debugging
3027 programs with large numbers of shared libraries the amount of output
3028 becomes less useful.
3030 set guile print-stack (none|message|full)
3031 show guile print-stack
3032 Show a stack trace when an error is encountered in a Guile script.
3034 set auto-load guile-scripts (on|off)
3035 show auto-load guile-scripts
3036 Control auto-loading of Guile script files.
3038 maint ada set ignore-descriptive-types (on|off)
3039 maint ada show ignore-descriptive-types
3040 Control whether the debugger should ignore descriptive types in Ada
3041 programs. The default is not to ignore the descriptive types. See
3042 the user manual for more details on descriptive types and the intended
3043 usage of this option.
3045 set auto-connect-native-target
3047 Control whether GDB is allowed to automatically connect to the
3048 native target for the run, attach, etc. commands when not connected
3049 to any target yet. See also "target native" below.
3051 set record btrace replay-memory-access (read-only|read-write)
3052 show record btrace replay-memory-access
3053 Control what memory accesses are allowed during replay.
3055 maint set target-async (on|off)
3056 maint show target-async
3057 This controls whether GDB targets operate in synchronous or
3058 asynchronous mode. Normally the default is asynchronous, if it is
3059 available; but this can be changed to more easily debug problems
3060 occurring only in synchronous mode.
3062 set mi-async (on|off)
3064 Control whether MI asynchronous mode is preferred. This supersedes
3065 "set target-async" of previous GDB versions.
3067 * "set target-async" is deprecated as a CLI option and is now an alias
3068 for "set mi-async" (only puts MI into async mode).
3070 * Background execution commands (e.g., "c&", "s&", etc.) are now
3071 possible ``out of the box'' if the target supports them. Previously
3072 the user would need to explicitly enable the possibility with the
3073 "set target-async on" command.
3075 * New features in the GDB remote stub, GDBserver
3077 ** New option --debug-format=option1[,option2,...] allows one to add
3078 additional text to each output. At present only timestamps
3079 are supported: --debug-format=timestamps.
3080 Timestamps can also be turned on with the
3081 "monitor set debug-format timestamps" command from GDB.
3083 * The 'record instruction-history' command now starts counting instructions
3084 at one. This also affects the instruction ranges reported by the
3085 'record function-call-history' command when given the /i modifier.
3087 * The command 'record function-call-history' supports a new modifier '/c' to
3088 indent the function names based on their call stack depth.
3089 The fields for the '/i' and '/l' modifier have been reordered.
3090 The source line range is now prefixed with 'at'.
3091 The instruction range is now prefixed with 'inst'.
3092 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3093 "record instruction-history" and "list" commands.
3095 * The ranges given as arguments to the 'record function-call-history' and
3096 'record instruction-history' commands are now inclusive.
3098 * The btrace record target now supports the 'record goto' command.
3099 For locations inside the execution trace, the back trace is computed
3100 based on the information stored in the execution trace.
3102 * The btrace record target supports limited reverse execution and replay.
3103 The target does not record data and therefore does not allow reading
3104 memory or registers.
3106 * The "catch syscall" command now works on s390*-linux* targets.
3108 * The "compare-sections" command is no longer specific to target
3109 remote. It now works with all targets.
3111 * All native targets are now consistently called "native".
3112 Consequently, the "target child", "target GNU", "target djgpp",
3113 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3114 commands have been replaced with "target native". The QNX/NTO port
3115 leaves the "procfs" target in place and adds a "native" target for
3116 consistency with other ports. The impact on users should be minimal
3117 as these commands previously either throwed an error, or were
3118 no-ops. The target's name is visible in the output of the following
3119 commands: "help target", "info target", "info files", "maint print
3122 * The "target native" command now connects to the native target. This
3123 can be used to launch native programs even when "set
3124 auto-connect-native-target" is set to off.
3126 * GDB now supports access to Intel MPX registers on GNU/Linux.
3128 * Support for Intel AVX-512 registers on GNU/Linux.
3129 Support displaying and modifying Intel AVX-512 registers
3130 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3132 * New remote packets
3134 qXfer:btrace:read's annex
3135 The qXfer:btrace:read packet supports a new annex 'delta' to read
3136 branch trace incrementally.
3140 ** Valid Python operations on gdb.Value objects representing
3141 structs/classes invoke the corresponding overloaded operators if
3143 ** New `Xmethods' feature in the Python API. Xmethods are
3144 additional methods or replacements for existing methods of a C++
3145 class. This feature is useful for those cases where a method
3146 defined in C++ source code could be inlined or optimized out by
3147 the compiler, making it unavailable to GDB.
3150 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3152 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3153 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3154 its alias "share", instead.
3156 * The commands "set remotebaud" and "show remotebaud" are no longer
3157 supported. Use "set serial baud" and "show serial baud" (respectively)
3162 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3163 target-async". The latter is left as a deprecated alias of the
3164 former for backward compatibility. If the target supports it,
3165 CLI background execution commands are now always possible by
3166 default, independently of whether the frontend stated a
3167 preference for asynchronous execution with "-gdb-set mi-async".
3168 Previously "-gdb-set target-async off" affected both MI execution
3169 commands and CLI execution commands.
3171 *** Changes in GDB 7.7
3173 * Improved support for process record-replay and reverse debugging on
3174 arm*-linux* targets. Support for thumb32 and syscall instruction
3175 recording has been added.
3177 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3179 * GDB now supports Fission DWP file format version 2.
3180 http://gcc.gnu.org/wiki/DebugFission
3182 * New convenience function "$_isvoid", to check whether an expression
3183 is void. A void expression is an expression where the type of the
3184 result is "void". For example, some convenience variables may be
3185 "void" when evaluated (e.g., "$_exitcode" before the execution of
3186 the program being debugged; or an undefined convenience variable).
3187 Another example, when calling a function whose return type is
3190 * The "maintenance print objfiles" command now takes an optional regexp.
3192 * The "catch syscall" command now works on arm*-linux* targets.
3194 * GDB now consistently shows "<not saved>" when printing values of
3195 registers the debug info indicates have not been saved in the frame
3196 and there's nowhere to retrieve them from
3197 (callee-saved/call-clobbered registers):
3202 (gdb) info registers rax
3205 Before, the former would print "<optimized out>", and the latter
3206 "*value not available*".
3208 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3213 ** Frame filters and frame decorators have been added.
3214 ** Temporary breakpoints are now supported.
3215 ** Line tables representation has been added.
3216 ** New attribute 'parent_type' for gdb.Field objects.
3217 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3218 ** New attribute 'name' for gdb.Type objects.
3222 Nios II ELF nios2*-*-elf
3223 Nios II GNU/Linux nios2*-*-linux
3224 Texas Instruments MSP430 msp430*-*-elf
3226 * Removed native configurations
3228 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3229 been removed. ELF variants of these configurations are kept supported.
3231 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3232 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3233 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3234 i[34567]86-*-openbsd3.[0-3]
3235 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3236 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3237 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3241 Like "catch throw", but catches a re-thrown exception.
3242 maint check-psymtabs
3243 Renamed from old "maint check-symtabs".
3245 Perform consistency checks on symtabs.
3246 maint expand-symtabs
3247 Expand symtabs matching an optional regexp.
3250 Display the details of GDB configure-time options.
3252 maint set|show per-command
3253 maint set|show per-command space
3254 maint set|show per-command time
3255 maint set|show per-command symtab
3256 Enable display of per-command gdb resource usage.
3258 remove-symbol-file FILENAME
3259 remove-symbol-file -a ADDRESS
3260 Remove a symbol file added via add-symbol-file. The file to remove
3261 can be identified by its filename or by an address that lies within
3262 the boundaries of this symbol file in memory.
3265 info exceptions REGEXP
3266 Display the list of Ada exceptions defined in the program being
3267 debugged. If provided, only the exceptions whose names match REGEXP
3272 set debug symfile off|on
3274 Control display of debugging info regarding reading symbol files and
3275 symbol tables within those files
3277 set print raw frame-arguments
3278 show print raw frame-arguments
3279 Set/show whether to print frame arguments in raw mode,
3280 disregarding any defined pretty-printers.
3282 set remote trace-status-packet
3283 show remote trace-status-packet
3284 Set/show the use of remote protocol qTStatus packet.
3288 Control display of debugging messages related to Nios II targets.
3292 Control whether target-assisted range stepping is enabled.
3294 set startup-with-shell
3295 show startup-with-shell
3296 Specifies whether Unix child processes are started via a shell or
3301 Use the target memory cache for accesses to the code segment. This
3302 improves performance of remote debugging (particularly disassembly).
3304 * You can now use a literal value 'unlimited' for options that
3305 interpret 0 or -1 as meaning "unlimited". E.g., "set
3306 trace-buffer-size unlimited" is now an alias for "set
3307 trace-buffer-size -1" and "set height unlimited" is now an alias for
3310 * The "set debug symtab-create" debugging option of GDB has been changed to
3311 accept a verbosity level. 0 means "off", 1 provides basic debugging
3312 output, and values of 2 or greater provides more verbose output.
3314 * New command-line options
3316 Display the details of GDB configure-time options.
3318 * The command 'tsave' can now support new option '-ctf' to save trace
3319 buffer in Common Trace Format.
3321 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3324 * GDB now implements the C++ 'typeid' operator.
3326 * The new convenience variable $_exception holds the exception being
3327 thrown or caught at an exception-related catchpoint.
3329 * The exception-related catchpoints, like "catch throw", now accept a
3330 regular expression which can be used to filter exceptions by type.
3332 * The new convenience variable $_exitsignal is automatically set to
3333 the terminating signal number when the program being debugged dies
3334 due to an uncaught signal.
3338 ** All MI commands now accept an optional "--language" option.
3339 Support for this feature can be verified by using the "-list-features"
3340 command, which should contain "language-option".
3342 ** The new command -info-gdb-mi-command allows the user to determine
3343 whether a GDB/MI command is supported or not.
3345 ** The "^error" result record returned when trying to execute an undefined
3346 GDB/MI command now provides a variable named "code" whose content is the
3347 "undefined-command" error code. Support for this feature can be verified
3348 by using the "-list-features" command, which should contain
3349 "undefined-command-error-code".
3351 ** The -trace-save MI command can optionally save trace buffer in Common
3354 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3356 ** The command -data-list-register-values now accepts an optional
3357 "--skip-unavailable" option. When used, only the available registers
3360 ** The new command -trace-frame-collected dumps collected variables,
3361 computed expressions, tvars, memory and registers in a traceframe.
3363 ** The commands -stack-list-locals, -stack-list-arguments and
3364 -stack-list-variables now accept an option "--skip-unavailable".
3365 When used, only the available locals or arguments are displayed.
3367 ** The -exec-run command now accepts an optional "--start" option.
3368 When used, the command follows the same semantics as the "start"
3369 command, stopping the program's execution at the start of its
3370 main subprogram. Support for this feature can be verified using
3371 the "-list-features" command, which should contain
3372 "exec-run-start-option".
3374 ** The new commands -catch-assert and -catch-exceptions insert
3375 catchpoints stopping the program when Ada exceptions are raised.
3377 ** The new command -info-ada-exceptions provides the equivalent of
3378 the new "info exceptions" command.
3380 * New system-wide configuration scripts
3381 A GDB installation now provides scripts suitable for use as system-wide
3382 configuration scripts for the following systems:
3386 * GDB now supports target-assigned range stepping with remote targets.
3387 This improves the performance of stepping source lines by reducing
3388 the number of control packets from/to GDB. See "New remote packets"
3391 * GDB now understands the element 'tvar' in the XML traceframe info.
3392 It has the id of the collected trace state variables.
3394 * On S/390 targets that provide the transactional-execution feature,
3395 the program interruption transaction diagnostic block (TDB) is now
3396 represented as a number of additional "registers" in GDB.
3398 * New remote packets
3402 The vCont packet supports a new 'r' action, that tells the remote
3403 stub to step through an address range itself, without GDB
3404 involvemement at each single-step.
3406 qXfer:libraries-svr4:read's annex
3407 The previously unused annex of the qXfer:libraries-svr4:read packet
3408 is now used to support passing an argument list. The remote stub
3409 reports support for this argument list to GDB's qSupported query.
3410 The defined arguments are "start" and "prev", used to reduce work
3411 necessary for library list updating, resulting in significant
3414 * New features in the GDB remote stub, GDBserver
3416 ** GDBserver now supports target-assisted range stepping. Currently
3417 enabled on x86/x86_64 GNU/Linux targets.
3419 ** GDBserver now adds element 'tvar' in the XML in the reply to
3420 'qXfer:traceframe-info:read'. It has the id of the collected
3421 trace state variables.
3423 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3426 * New 'z' formatter for printing and examining memory, this displays the
3427 value as hexadecimal zero padded on the left to the size of the type.
3429 * GDB can now use Windows x64 unwinding data.
3431 * The "set remotebaud" command has been replaced by "set serial baud".
3432 Similarly, "show remotebaud" has been replaced by "show serial baud".
3433 The "set remotebaud" and "show remotebaud" commands are still available
3434 to provide backward compatibility with older versions of GDB.
3436 *** Changes in GDB 7.6
3438 * Target record has been renamed to record-full.
3439 Record/replay is now enabled with the "record full" command.
3440 This also affects settings that are associated with full record/replay
3441 that have been moved from "set/show record" to "set/show record full":
3443 set|show record full insn-number-max
3444 set|show record full stop-at-limit
3445 set|show record full memory-query
3447 * A new record target "record-btrace" has been added. The new target
3448 uses hardware support to record the control-flow of a process. It
3449 does not support replaying the execution, but it implements the
3450 below new commands for investigating the recorded execution log.
3451 This new recording method can be enabled using:
3455 The "record-btrace" target is only available on Intel Atom processors
3456 and requires a Linux kernel 2.6.32 or later.
3458 * Two new commands have been added for record/replay to give information
3459 about the recorded execution without having to replay the execution.
3460 The commands are only supported by "record btrace".
3462 record instruction-history prints the execution history at
3463 instruction granularity
3465 record function-call-history prints the execution history at
3466 function granularity
3468 * New native configurations
3470 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3471 FreeBSD/powerpc powerpc*-*-freebsd
3472 x86_64/Cygwin x86_64-*-cygwin*
3473 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3477 ARM AArch64 aarch64*-*-elf
3478 ARM AArch64 GNU/Linux aarch64*-*-linux
3479 Lynx 178 PowerPC powerpc-*-lynx*178
3480 x86_64/Cygwin x86_64-*-cygwin*
3481 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3483 * If the configured location of system.gdbinit file (as given by the
3484 --with-system-gdbinit option at configure time) is in the
3485 data-directory (as specified by --with-gdb-datadir at configure
3486 time) or in one of its subdirectories, then GDB will look for the
3487 system-wide init file in the directory specified by the
3488 --data-directory command-line option.
3490 * New command line options:
3492 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3493 other initialization files, unlike -nx which disables all of them.
3495 * Removed command line options
3497 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3500 * The 'ptype' and 'whatis' commands now accept an argument to control
3503 * 'info proc' now works on some core files.
3507 ** Vectors can be created with gdb.Type.vector.
3509 ** Python's atexit.register now works in GDB.
3511 ** Types can be pretty-printed via a Python API.
3513 ** Python 3 is now supported (in addition to Python 2.4 or later)
3515 ** New class gdb.Architecture exposes GDB's internal representation
3516 of architecture in the Python API.
3518 ** New method Frame.architecture returns the gdb.Architecture object
3519 corresponding to the frame's architecture.
3521 * New Python-based convenience functions:
3523 ** $_memeq(buf1, buf2, length)
3524 ** $_streq(str1, str2)
3526 ** $_regex(str, regex)
3528 * The 'cd' command now defaults to using '~' (the home directory) if not
3531 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3532 default for GCC since November 2000.
3534 * The command 'forward-search' can now be abbreviated as 'fo'.
3536 * The command 'info tracepoints' can now display 'installed on target'
3537 or 'not installed on target' for each non-pending location of tracepoint.
3539 * New configure options
3541 --enable-libmcheck/--disable-libmcheck
3542 By default, development versions are built with -lmcheck on hosts
3543 that support it, in order to help track memory corruption issues.
3544 Release versions, on the other hand, are built without -lmcheck
3545 by default. The --enable-libmcheck/--disable-libmcheck configure
3546 options allow the user to override that default.
3547 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3548 This configure option allows the user to build GDB with
3549 libbabeltrace using which GDB can read Common Trace Format data.
3551 * New commands (for set/show, see "New options" below)
3554 Catch signals. This is similar to "handle", but allows commands and
3555 conditions to be attached.
3558 List the BFDs known to GDB.
3560 python-interactive [command]
3562 Start a Python interactive prompt, or evaluate the optional command
3563 and print the result of expressions.
3566 "py" is a new alias for "python".
3568 enable type-printer [name]...
3569 disable type-printer [name]...
3570 Enable or disable type printers.
3574 ** For the Renesas Super-H architecture, the "regs" command has been removed
3575 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3580 set print type methods (on|off)
3581 show print type methods
3582 Control whether method declarations are displayed by "ptype".
3583 The default is to show them.
3585 set print type typedefs (on|off)
3586 show print type typedefs
3587 Control whether typedef definitions are displayed by "ptype".
3588 The default is to show them.
3590 set filename-display basename|relative|absolute
3591 show filename-display
3592 Control the way in which filenames is displayed.
3593 The default is "relative", which preserves previous behavior.
3595 set trace-buffer-size
3596 show trace-buffer-size
3597 Request target to change the size of trace buffer.
3599 set remote trace-buffer-size-packet auto|on|off
3600 show remote trace-buffer-size-packet
3601 Control the use of the remote protocol `QTBuffer:size' packet.
3605 Control display of debugging messages related to ARM AArch64.
3608 set debug coff-pe-read
3609 show debug coff-pe-read
3610 Control display of debugging messages related to reading of COFF/PE
3615 Control display of debugging messages related to Mach-O symbols
3618 set debug notification
3619 show debug notification
3620 Control display of debugging info for async remote notification.
3624 ** Command parameter changes are now notified using new async record
3625 "=cmd-param-changed".
3626 ** Trace frame changes caused by command "tfind" are now notified using
3627 new async record "=traceframe-changed".
3628 ** The creation, deletion and modification of trace state variables
3629 are now notified using new async records "=tsv-created",
3630 "=tsv-deleted" and "=tsv-modified".
3631 ** The start and stop of process record are now notified using new
3632 async record "=record-started" and "=record-stopped".
3633 ** Memory changes are now notified using new async record
3635 ** The data-disassemble command response will include a "fullname" field
3636 containing the absolute file name when source has been requested.
3637 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3638 command, to allow pattern filling of memory areas.
3639 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3640 library load/unload events.
3641 ** The response to breakpoint commands and breakpoint async records
3642 includes an "installed" field containing a boolean state about each
3643 non-pending tracepoint location is whether installed on target or not.
3644 ** Output of the "-trace-status" command includes a "trace-file" field
3645 containing the name of the trace file being examined. This field is
3646 optional, and only present when examining a trace file.
3647 ** The "fullname" field is now always present along with the "file" field,
3648 even if the file cannot be found by GDB.
3650 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3651 You must have the LZMA library available when configuring GDB for this
3652 feature to be enabled. For more information, see:
3653 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3655 * New remote packets
3658 Set the size of trace buffer. The remote stub reports support for this
3659 packet to gdb's qSupported query.
3662 Enable Branch Trace Store (BTS)-based branch tracing for the current
3663 thread. The remote stub reports support for this packet to gdb's
3667 Disable branch tracing for the current thread. The remote stub reports
3668 support for this packet to gdb's qSupported query.
3671 Read the traced branches for the current thread. The remote stub
3672 reports support for this packet to gdb's qSupported query.
3674 *** Changes in GDB 7.5
3676 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3677 for more x32 ABI info.
3679 * GDB now supports access to MIPS DSP registers on Linux targets.
3681 * GDB now supports debugging microMIPS binaries.
3683 * The "info os" command on GNU/Linux can now display information on
3684 several new classes of objects managed by the operating system:
3685 "info os procgroups" lists process groups
3686 "info os files" lists file descriptors
3687 "info os sockets" lists internet-domain sockets
3688 "info os shm" lists shared-memory regions
3689 "info os semaphores" lists semaphores
3690 "info os msg" lists message queues
3691 "info os modules" lists loaded kernel modules
3693 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3694 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3695 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3696 options and inspect the probe arguments using the new $_probe_arg family
3697 of convenience variables. You can obtain more information about SystemTap
3698 in <http://sourceware.org/systemtap/>.
3700 * GDB now supports reversible debugging on ARM, it allows you to
3701 debug basic ARM and THUMB instructions, and provides
3702 record/replay support.
3704 * The option "symbol-reloading" has been deleted as it is no longer used.
3708 ** GDB commands implemented in Python can now be put in command class
3711 ** The "maint set python print-stack on|off" is now deleted.
3713 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3714 apply "flag enum"-style pretty-printing to any enum.
3716 ** gdb.lookup_symbol can now work when there is no current frame.
3718 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3719 the source at which the symbol was defined.
3721 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3722 method 'value'. The former indicates whether the symbol needs a
3723 frame in order to compute its value, and the latter computes the
3726 ** A new method 'referenced_value' on gdb.Value objects which can
3727 dereference pointer as well as C++ reference values.
3729 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3730 which return the global and static blocks (as gdb.Block objects),
3731 of the underlying symbol table, respectively.
3733 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3734 object associated with a PC value.
3736 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3737 of the address range occupied by code for the current source line.
3739 * Go language support.
3740 GDB now supports debugging programs written in the Go programming
3743 * GDBserver now supports stdio connections.
3744 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3746 * The binary "gdbtui" can no longer be built or installed.
3747 Use "gdb -tui" instead.
3749 * GDB will now print "flag" enums specially. A flag enum is one where
3750 all the enumerator values have no bits in common when pairwise
3751 "and"ed. When printing a value whose type is a flag enum, GDB will
3752 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3753 (gdb) print (enum E) 3
3756 * The filename part of a linespec will now match trailing components
3757 of a source file name. For example, "break gcc/expr.c:1000" will
3758 now set a breakpoint in build/gcc/expr.c, but not
3759 build/libcpp/expr.c.
3761 * The "info proc" and "generate-core-file" commands will now also
3762 work on remote targets connected to GDBserver on Linux.
3764 * The command "info catch" has been removed. It has been disabled
3765 since December 2007.
3767 * The "catch exception" and "catch assert" commands now accept
3768 a condition at the end of the command, much like the "break"
3769 command does. For instance:
3771 (gdb) catch exception Constraint_Error if Barrier = True
3773 Previously, it was possible to add a condition to such catchpoints,
3774 but it had to be done as a second step, after the catchpoint had been
3775 created, using the "condition" command.
3777 * The "info static-tracepoint-marker" command will now also work on
3778 native Linux targets with in-process agent.
3780 * GDB can now set breakpoints on inlined functions.
3782 * The .gdb_index section has been updated to include symbols for
3783 inlined functions. GDB will ignore older .gdb_index sections by
3784 default, which could cause symbol files to be loaded more slowly
3785 until their .gdb_index sections can be recreated. The new command
3786 "set use-deprecated-index-sections on" will cause GDB to use any older
3787 .gdb_index sections it finds. This will restore performance, but the
3788 ability to set breakpoints on inlined functions will be lost in symbol
3789 files with older .gdb_index sections.
3791 The .gdb_index section has also been updated to record more information
3792 about each symbol. This speeds up the "info variables", "info functions"
3793 and "info types" commands when used with programs having the .gdb_index
3794 section, as well as speeding up debugging with shared libraries using
3795 the .gdb_index section.
3797 * Ada support for GDB/MI Variable Objects has been added.
3799 * GDB can now support 'breakpoint always-inserted mode' in 'record'
3804 ** New command -info-os is the MI equivalent of "info os".
3806 ** Output logs ("set logging" and related) now include MI output.
3810 ** "set use-deprecated-index-sections on|off"
3811 "show use-deprecated-index-sections on|off"
3812 Controls the use of deprecated .gdb_index sections.
3814 ** "catch load" and "catch unload" can be used to stop when a shared
3815 library is loaded or unloaded, respectively.
3817 ** "enable count" can be used to auto-disable a breakpoint after
3820 ** "info vtbl" can be used to show the virtual method tables for
3821 C++ and Java objects.
3823 ** "explore" and its sub commands "explore value" and "explore type"
3824 can be used to recursively explore values and types of
3825 expressions. These commands are available only if GDB is
3826 configured with '--with-python'.
3828 ** "info auto-load" shows status of all kinds of auto-loaded files,
3829 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
3830 sequences of commands files, "info auto-load python-scripts"
3831 shows status of auto-loading Python script files,
3832 "info auto-load local-gdbinit" shows status of loading init file
3833 (.gdbinit) from current directory and "info auto-load libthread-db" shows
3834 status of inferior specific thread debugging shared library loading.
3836 ** "info auto-load-scripts", "set auto-load-scripts on|off"
3837 and "show auto-load-scripts" commands have been deprecated, use their
3838 "info auto-load python-scripts", "set auto-load python-scripts on|off"
3839 and "show auto-load python-scripts" counterparts instead.
3841 ** "dprintf location,format,args..." creates a dynamic printf, which
3842 is basically a breakpoint that does a printf and immediately
3843 resumes your program's execution, so it is like a printf that you
3844 can insert dynamically at runtime instead of at compiletime.
3846 ** "set print symbol"
3848 Controls whether GDB attempts to display the symbol, if any,
3849 corresponding to addresses it prints. This defaults to "on", but
3850 you can set it to "off" to restore GDB's previous behavior.
3852 * Deprecated commands
3854 ** For the Renesas Super-H architecture, the "regs" command has been
3855 deprecated, and "info all-registers" should be used instead.
3859 Renesas RL78 rl78-*-elf
3860 HP OpenVMS ia64 ia64-hp-openvms*
3862 * GDBserver supports evaluation of breakpoint conditions. When
3863 support is advertised by GDBserver, GDB may be told to send the
3864 breakpoint conditions in bytecode form to GDBserver. GDBserver
3865 will only report the breakpoint trigger to GDB when its condition
3870 set mips compression
3871 show mips compression
3872 Select the compressed ISA encoding used in functions that have no symbol
3873 information available. The encoding can be set to either of:
3876 and is updated automatically from ELF file flags if available.
3878 set breakpoint condition-evaluation
3879 show breakpoint condition-evaluation
3880 Control whether breakpoint conditions are evaluated by GDB ("host") or by
3881 GDBserver ("target"). Default option "auto" chooses the most efficient
3883 This option can improve debugger efficiency depending on the speed of the
3887 Disable auto-loading globally.
3890 Show auto-loading setting of all kinds of auto-loaded files.
3892 set auto-load gdb-scripts on|off
3893 show auto-load gdb-scripts
3894 Control auto-loading of GDB canned sequences of commands files.
3896 set auto-load python-scripts on|off
3897 show auto-load python-scripts
3898 Control auto-loading of Python script files.
3900 set auto-load local-gdbinit on|off
3901 show auto-load local-gdbinit
3902 Control loading of init file (.gdbinit) from current directory.
3904 set auto-load libthread-db on|off
3905 show auto-load libthread-db
3906 Control auto-loading of inferior specific thread debugging shared library.
3908 set auto-load scripts-directory <dir1>[:<dir2>...]
3909 show auto-load scripts-directory
3910 Set a list of directories from which to load auto-loaded scripts.
3911 Automatically loaded Python scripts and GDB scripts are located in one
3912 of the directories listed by this option.
3913 The delimiter (':' above) may differ according to the host platform.
3915 set auto-load safe-path <dir1>[:<dir2>...]
3916 show auto-load safe-path
3917 Set a list of directories from which it is safe to auto-load files.
3918 The delimiter (':' above) may differ according to the host platform.
3920 set debug auto-load on|off
3921 show debug auto-load
3922 Control display of debugging info for auto-loading the files above.
3924 set dprintf-style gdb|call|agent
3926 Control the way in which a dynamic printf is performed; "gdb"
3927 requests a GDB printf command, while "call" causes dprintf to call a
3928 function in the inferior. "agent" requests that the target agent
3929 (such as GDBserver) do the printing.
3931 set dprintf-function <expr>
3932 show dprintf-function
3933 set dprintf-channel <expr>
3934 show dprintf-channel
3935 Set the function and optional first argument to the call when using
3936 the "call" style of dynamic printf.
3938 set disconnected-dprintf on|off
3939 show disconnected-dprintf
3940 Control whether agent-style dynamic printfs continue to be in effect
3941 after GDB disconnects.
3943 * New configure options
3945 --with-auto-load-dir
3946 Configure default value for the 'set auto-load scripts-directory'
3947 setting above. It defaults to '$debugdir:$datadir/auto-load',
3948 $debugdir representing global debugging info directories (available
3949 via 'show debug-file-directory') and $datadir representing GDB's data
3950 directory (available via 'show data-directory').
3952 --with-auto-load-safe-path
3953 Configure default value for the 'set auto-load safe-path' setting
3954 above. It defaults to the --with-auto-load-dir setting.
3956 --without-auto-load-safe-path
3957 Set 'set auto-load safe-path' to '/', effectively disabling this
3960 * New remote packets
3962 z0/z1 conditional breakpoints extension
3964 The z0/z1 breakpoint insertion packets have been extended to carry
3965 a list of conditional expressions over to the remote stub depending on the
3966 condition evaluation mode. The use of this extension can be controlled
3967 via the "set remote conditional-breakpoints-packet" command.
3971 Specify the signals which the remote stub may pass to the debugged
3972 program without GDB involvement.
3974 * New command line options
3976 --init-command=FILE, -ix Like --command, -x but execute it
3977 before loading inferior.
3978 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
3979 execute it before loading inferior.
3981 *** Changes in GDB 7.4
3983 * GDB now handles ambiguous linespecs more consistently; the existing
3984 FILE:LINE support has been expanded to other types of linespecs. A
3985 breakpoint will now be set on all matching locations in all
3986 inferiors, and locations will be added or removed according to
3989 * GDB now allows you to skip uninteresting functions and files when
3990 stepping with the "skip function" and "skip file" commands.
3992 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
3993 and "show remote hardware-watchpoint-length-limit". These allows to
3994 set or show the maximum length limit (in bytes) of a remote
3995 target hardware watchpoint.
3997 This allows e.g. to use "unlimited" hardware watchpoints with the
3998 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
3999 watchpoints are slower than real hardware watchpoints but are
4000 significantly faster than gdb software watchpoints.
4004 ** The register_pretty_printer function in module gdb.printing now takes
4005 an optional `replace' argument. If True, the new printer replaces any
4008 ** The "maint set python print-stack on|off" command has been
4009 deprecated and will be deleted in GDB 7.5.
4010 A new command: "set python print-stack none|full|message" has
4011 replaced it. Additionally, the default for "print-stack" is
4012 now "message", which just prints the error message without
4015 ** A prompt substitution hook (prompt_hook) is now available to the
4018 ** A new Python module, gdb.prompt has been added to the GDB Python
4019 modules library. This module provides functionality for
4020 escape sequences in prompts (used by set/show
4021 extended-prompt). These escape sequences are replaced by their
4022 corresponding value.
4024 ** Python commands and convenience-functions located in
4025 'data-directory'/python/gdb/command and
4026 'data-directory'/python/gdb/function are now automatically loaded
4029 ** Blocks now provide four new attributes. global_block and
4030 static_block will return the global and static blocks
4031 respectively. is_static and is_global are boolean attributes
4032 that indicate if the block is one of those two types.
4034 ** Symbols now provide the "type" attribute, the type of the symbol.
4036 ** The "gdb.breakpoint" function has been deprecated in favor of
4039 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4040 of a function. This class is based on the "finish" command
4041 available in the CLI.
4043 ** Type objects for struct and union types now allow access to
4044 the fields using standard Python dictionary (mapping) methods.
4045 For example, "some_type['myfield']" now works, as does
4046 "some_type.items()".
4048 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4051 ** A new function, "deep_items" has been added to the gdb.types
4052 module in the GDB Python modules library. This function returns
4053 an iterator over the fields of a struct or union type. Unlike
4054 the standard Python "iteritems" method, it will recursively traverse
4055 any anonymous fields.
4059 ** "*stopped" events can report several new "reason"s, such as
4062 ** Breakpoint changes are now notified using new async records, like
4063 "=breakpoint-modified".
4065 ** New command -ada-task-info.
4067 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4068 $sdir specifies the default system locations of shared libraries.
4069 $pdir specifies the directory where the libpthread used by the application
4072 GDB no longer looks in $sdir and $pdir after it has searched the directories
4073 mentioned in libthread-db-search-path. If you want to search those
4074 directories, they must be specified in libthread-db-search-path.
4075 The default value of libthread-db-search-path on GNU/Linux and Solaris
4076 systems is now "$sdir:$pdir".
4078 $pdir is not supported by gdbserver, it is currently ignored.
4079 $sdir is supported by gdbserver.
4081 * New configure option --with-iconv-bin.
4082 When using the internationalization support like the one in the GNU C
4083 library, GDB will invoke the "iconv" program to get a list of supported
4084 character sets. If this program lives in a non-standard location, one can
4085 use this option to specify where to find it.
4087 * When natively debugging programs on PowerPC BookE processors running
4088 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4089 watchpoints, which specify a mask in addition to an address to watch.
4090 The mask specifies that some bits of an address (the bits which are
4091 reset in the mask) should be ignored when matching the address accessed
4092 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4093 section in the user manual for more details.
4095 * The new option --once causes GDBserver to stop listening for connections once
4096 the first connection is made. The listening port used by GDBserver will
4097 become available after that.
4099 * New commands "info macros" and "alias" have been added.
4101 * New function parameters suffix @entry specifies value of function parameter
4102 at the time the function got called. Entry values are available only since
4108 "!" is now an alias of the "shell" command.
4109 Note that no space is needed between "!" and SHELL COMMAND.
4113 watch EXPRESSION mask MASK_VALUE
4114 The watch command now supports the mask argument which allows creation
4115 of masked watchpoints, if the current architecture supports this feature.
4117 info auto-load-scripts [REGEXP]
4118 This command was formerly named "maintenance print section-scripts".
4119 It is now generally useful and is no longer a maintenance-only command.
4121 info macro [-all] [--] MACRO
4122 The info macro command has new options `-all' and `--'. The first for
4123 printing all definitions of a macro. The second for explicitly specifying
4124 the end of arguments and the beginning of the macro name in case the macro
4125 name starts with a hyphen.
4127 collect[/s] EXPRESSIONS
4128 The tracepoint collect command now takes an optional modifier "/s"
4129 that directs it to dereference pointer-to-character types and
4130 collect the bytes of memory up to a zero byte. The behavior is
4131 similar to what you see when you use the regular print command on a
4132 string. An optional integer following the "/s" sets a bound on the
4133 number of bytes that will be collected.
4136 The trace start command now interprets any supplied arguments as a
4137 note to be recorded with the trace run, with an effect similar to
4138 setting the variable trace-notes.
4141 The trace stop command now interprets any arguments as a note to be
4142 mentioned along with the tstatus report that the trace was stopped
4143 with a command. The effect is similar to setting the variable
4146 * Tracepoints can now be enabled and disabled at any time after a trace
4147 experiment has been started using the standard "enable" and "disable"
4148 commands. It is now possible to start a trace experiment with no enabled
4149 tracepoints; GDB will display a warning, but will allow the experiment to
4150 begin, assuming that tracepoints will be enabled as needed while the trace
4153 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4154 locations with 4-byte instructions, when they were previously
4155 limited to locations with instructions of 5 bytes or longer.
4159 set debug dwarf2-read
4160 show debug dwarf2-read
4161 Turns on or off display of debugging messages related to reading
4162 DWARF debug info. The default is off.
4164 set debug symtab-create
4165 show debug symtab-create
4166 Turns on or off display of debugging messages related to symbol table
4167 creation. The default is off.
4170 show extended-prompt
4171 Set the GDB prompt, and allow escape sequences to be inserted to
4172 display miscellaneous information (see 'help set extended-prompt'
4173 for the list of sequences). This prompt (and any information
4174 accessed through the escape sequences) is updated every time the
4175 prompt is displayed.
4177 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4178 show print entry-values
4179 Set printing of frame argument values at function entry. In some cases
4180 GDB can determine the value of function argument which was passed by the
4181 function caller, even if the value was modified inside the called function.
4183 set debug entry-values
4184 show debug entry-values
4185 Control display of debugging info for determining frame argument values at
4186 function entry and virtual tail call frames.
4188 set basenames-may-differ
4189 show basenames-may-differ
4190 Set whether a source file may have multiple base names.
4191 (A "base name" is the name of a file with the directory part removed.
4192 Example: The base name of "/home/user/hello.c" is "hello.c".)
4193 If set, GDB will canonicalize file names (e.g., expand symlinks)
4194 before comparing them. Canonicalization is an expensive operation,
4195 but it allows the same file be known by more than one base name.
4196 If not set (the default), all source files are assumed to have just
4197 one base name, and gdb will do file name comparisons more efficiently.
4203 Set a user name and notes for the current and any future trace runs.
4204 This is useful for long-running and/or disconnected traces, to
4205 inform others (or yourself) as to who is running the trace, supply
4206 contact information, or otherwise explain what is going on.
4208 set trace-stop-notes
4209 show trace-stop-notes
4210 Set a note attached to the trace run, that is displayed when the
4211 trace has been stopped by a tstop command. This is useful for
4212 instance as an explanation, if you are stopping a trace run that was
4213 started by someone else.
4215 * New remote packets
4219 Dynamically enable a tracepoint in a started trace experiment.
4223 Dynamically disable a tracepoint in a started trace experiment.
4227 Set the user and notes of the trace run.
4231 Query the current status of a tracepoint.
4235 Query the minimum length of instruction at which a fast tracepoint may
4238 * Dcache size (number of lines) and line-size are now runtime-configurable
4239 via "set dcache line" and "set dcache line-size" commands.
4243 Texas Instruments TMS320C6x tic6x-*-*
4247 Renesas RL78 rl78-*-elf
4249 *** Changes in GDB 7.3.1
4251 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4253 *** Changes in GDB 7.3
4255 * GDB has a new command: "thread find [REGEXP]".
4256 It finds the thread id whose name, target id, or thread extra info
4257 matches the given regular expression.
4259 * The "catch syscall" command now works on mips*-linux* targets.
4261 * The -data-disassemble MI command now supports modes 2 and 3 for
4262 dumping the instruction opcodes.
4264 * New command line options
4266 -data-directory DIR Specify DIR as the "data-directory".
4267 This is mostly for testing purposes.
4269 * The "maint set python auto-load on|off" command has been renamed to
4270 "set auto-load-scripts on|off".
4272 * GDB has a new command: "set directories".
4273 It is like the "dir" command except that it replaces the
4274 source path list instead of augmenting it.
4276 * GDB now understands thread names.
4278 On GNU/Linux, "info threads" will display the thread name as set by
4279 prctl or pthread_setname_np.
4281 There is also a new command, "thread name", which can be used to
4282 assign a name internally for GDB to display.
4285 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4286 has been integrated into GDB.
4290 ** The function gdb.Write now accepts an optional keyword 'stream'.
4291 This keyword, when provided, will direct the output to either
4292 stdout, stderr, or GDB's logging output.
4294 ** Parameters can now be be sub-classed in Python, and in particular
4295 you may implement the get_set_doc and get_show_doc functions.
4296 This improves how Parameter set/show documentation is processed
4297 and allows for more dynamic content.
4299 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4300 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4301 have an is_valid method.
4303 ** Breakpoints can now be sub-classed in Python, and in particular
4304 you may implement a 'stop' function that is executed each time
4305 the inferior reaches that breakpoint.
4307 ** New function gdb.lookup_global_symbol looks up a global symbol.
4309 ** GDB values in Python are now callable if the value represents a
4310 function. For example, if 'some_value' represents a function that
4311 takes two integer parameters and returns a value, you can call
4312 that function like so:
4314 result = some_value (10,20)
4316 ** Module gdb.types has been added.
4317 It contains a collection of utilities for working with gdb.Types objects:
4318 get_basic_type, has_field, make_enum_dict.
4320 ** Module gdb.printing has been added.
4321 It contains utilities for writing and registering pretty-printers.
4322 New classes: PrettyPrinter, SubPrettyPrinter,
4323 RegexpCollectionPrettyPrinter.
4324 New function: register_pretty_printer.
4326 ** New commands "info pretty-printers", "enable pretty-printer" and
4327 "disable pretty-printer" have been added.
4329 ** gdb.parameter("directories") is now available.
4331 ** New function gdb.newest_frame returns the newest frame in the
4334 ** The gdb.InferiorThread class has a new "name" attribute. This
4335 holds the thread's name.
4337 ** Python Support for Inferior events.
4338 Python scripts can add observers to be notified of events
4339 occurring in the process being debugged.
4340 The following events are currently supported:
4341 - gdb.events.cont Continue event.
4342 - gdb.events.exited Inferior exited event.
4343 - gdb.events.stop Signal received, and Breakpoint hit events.
4347 ** GDB now puts template parameters in scope when debugging in an
4348 instantiation. For example, if you have:
4350 template<int X> int func (void) { return X; }
4352 then if you step into func<5>, "print X" will show "5". This
4353 feature requires proper debuginfo support from the compiler; it
4354 was added to GCC 4.5.
4356 ** The motion commands "next", "finish", "until", and "advance" now
4357 work better when exceptions are thrown. In particular, GDB will
4358 no longer lose control of the inferior; instead, the GDB will
4359 stop the inferior at the point at which the exception is caught.
4360 This functionality requires a change in the exception handling
4361 code that was introduced in GCC 4.5.
4363 * GDB now follows GCC's rules on accessing volatile objects when
4364 reading or writing target state during expression evaluation.
4365 One notable difference to prior behavior is that "print x = 0"
4366 no longer generates a read of x; the value of the assignment is
4367 now always taken directly from the value being assigned.
4369 * GDB now has some support for using labels in the program's source in
4370 linespecs. For instance, you can use "advance label" to continue
4371 execution to a label.
4373 * GDB now has support for reading and writing a new .gdb_index
4374 section. This section holds a fast index of DWARF debugging
4375 information and can be used to greatly speed up GDB startup and
4376 operation. See the documentation for `save gdb-index' for details.
4378 * The "watch" command now accepts an optional "-location" argument.
4379 When used, this causes GDB to watch the memory referred to by the
4380 expression. Such a watchpoint is never deleted due to it going out
4383 * GDB now supports thread debugging of core dumps on GNU/Linux.
4385 GDB now activates thread debugging using the libthread_db library
4386 when debugging GNU/Linux core dumps, similarly to when debugging
4387 live processes. As a result, when debugging a core dump file, GDB
4388 is now able to display pthread_t ids of threads. For example, "info
4389 threads" shows the same output as when debugging the process when it
4390 was live. In earlier releases, you'd see something like this:
4393 * 1 LWP 6780 main () at main.c:10
4395 While now you see this:
4398 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4400 It is also now possible to inspect TLS variables when debugging core
4403 When debugging a core dump generated on a machine other than the one
4404 used to run GDB, you may need to point GDB at the correct
4405 libthread_db library with the "set libthread-db-search-path"
4406 command. See the user manual for more details on this command.
4408 * When natively debugging programs on PowerPC BookE processors running
4409 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4410 which stop execution of the inferior whenever it executes an instruction
4411 at any address within the specified range. See the "PowerPC Embedded"
4412 section in the user manual for more details.
4414 * New features in the GDB remote stub, GDBserver
4416 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4417 and i686 LynxOS (version 5.x).
4419 ** GDBserver is now supported on Blackfin Linux.
4421 * New native configurations
4423 ia64 HP-UX ia64-*-hpux*
4427 Analog Devices, Inc. Blackfin Processor bfin-*
4429 * Ada task switching is now supported on sparc-elf targets when
4430 debugging a program using the Ravenscar Profile. For more information,
4431 see the "Tasking Support when using the Ravenscar Profile" section
4432 in the GDB user manual.
4434 * Guile support was removed.
4436 * New features in the GNU simulator
4438 ** The --map-info flag lists all known core mappings.
4440 ** CFI flashes may be simulated via the "cfi" device.
4442 *** Changes in GDB 7.2
4444 * Shared library support for remote targets by default
4446 When GDB is configured for a generic, non-OS specific target, like
4447 for example, --target=arm-eabi or one of the many *-*-elf targets,
4448 GDB now queries remote stubs for loaded shared libraries using the
4449 `qXfer:libraries:read' packet. Previously, shared library support
4450 was always disabled for such configurations.
4454 ** Argument Dependent Lookup (ADL)
4456 In C++ ADL lookup directs function search to the namespaces of its
4457 arguments even if the namespace has not been imported.
4467 Here the compiler will search for `foo' in the namespace of 'b'
4468 and find A::foo. GDB now supports this. This construct is commonly
4469 used in the Standard Template Library for operators.
4471 ** Improved User Defined Operator Support
4473 In addition to member operators, GDB now supports lookup of operators
4474 defined in a namespace and imported with a `using' directive, operators
4475 defined in the global scope, operators imported implicitly from an
4476 anonymous namespace, and the ADL operators mentioned in the previous
4478 GDB now also supports proper overload resolution for all the previously
4479 mentioned flavors of operators.
4481 ** static const class members
4483 Printing of static const class members that are initialized in the
4484 class definition has been fixed.
4486 * Windows Thread Information Block access.
4488 On Windows targets, GDB now supports displaying the Windows Thread
4489 Information Block (TIB) structure. This structure is visible either
4490 by using the new command `info w32 thread-information-block' or, by
4491 dereferencing the new convenience variable named `$_tlb', a
4492 thread-specific pointer to the TIB. This feature is also supported
4493 when remote debugging using GDBserver.
4495 * Static tracepoints
4497 Static tracepoints are calls in the user program into a tracing
4498 library. One such library is a port of the LTTng kernel tracer to
4499 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4500 When debugging with GDBserver, GDB now supports combining the GDB
4501 tracepoint machinery with such libraries. For example: the user can
4502 use GDB to probe a static tracepoint marker (a call from the user
4503 program into the tracing library) with the new "strace" command (see
4504 "New commands" below). This creates a "static tracepoint" in the
4505 breakpoint list, that can be manipulated with the same feature set
4506 as fast and regular tracepoints. E.g., collect registers, local and
4507 global variables, collect trace state variables, and define
4508 tracepoint conditions. In addition, the user can collect extra
4509 static tracepoint marker specific data, by collecting the new
4510 $_sdata internal variable. When analyzing the trace buffer, you can
4511 inspect $_sdata like any other variable available to GDB. For more
4512 information, see the "Tracepoints" chapter in GDB user manual. New
4513 remote packets have been defined to support static tracepoints, see
4514 the "New remote packets" section below.
4516 * Better reconstruction of tracepoints after disconnected tracing
4518 GDB will attempt to download the original source form of tracepoint
4519 definitions when starting a trace run, and then will upload these
4520 upon reconnection to the target, resulting in a more accurate
4521 reconstruction of the tracepoints that are in use on the target.
4525 You can now exercise direct control over the ways that GDB can
4526 affect your program. For instance, you can disallow the setting of
4527 breakpoints, so that the program can run continuously (assuming
4528 non-stop mode). In addition, the "observer" variable is available
4529 to switch all of the different controls; in observer mode, GDB
4530 cannot affect the target's behavior at all, which is useful for
4531 tasks like diagnosing live systems in the field.
4533 * The new convenience variable $_thread holds the number of the
4536 * New remote packets
4540 Return the address of the Windows Thread Information Block of a given thread.
4544 In response to several of the tracepoint packets, the target may now
4545 also respond with a number of intermediate `qRelocInsn' request
4546 packets before the final result packet, to have GDB handle
4547 relocating an instruction to execute at a different address. This
4548 is particularly useful for stubs that support fast tracepoints. GDB
4549 reports support for this feature in the qSupported packet.
4553 List static tracepoint markers in the target program.
4557 List static tracepoint markers at a given address in the target
4560 qXfer:statictrace:read
4562 Read the static trace data collected (by a `collect $_sdata'
4563 tracepoint action). The remote stub reports support for this packet
4564 to gdb's qSupported query.
4568 Send the current settings of GDB's permission flags.
4572 Send part of the source (textual) form of a tracepoint definition,
4573 which includes location, conditional, and action list.
4575 * The source command now accepts a -s option to force searching for the
4576 script in the source search path even if the script name specifies
4579 * New features in the GDB remote stub, GDBserver
4581 - GDBserver now support tracepoints (including fast tracepoints, and
4582 static tracepoints). The feature is currently supported by the
4583 i386-linux and amd64-linux builds. See the "Tracepoints support
4584 in gdbserver" section in the manual for more information.
4586 GDBserver JIT compiles the tracepoint's conditional agent
4587 expression bytecode into native code whenever possible for low
4588 overhead dynamic tracepoints conditionals. For such tracepoints,
4589 an expression that examines program state is evaluated when the
4590 tracepoint is reached, in order to determine whether to capture
4591 trace data. If the condition is simple and false, processing the
4592 tracepoint finishes very quickly and no data is gathered.
4594 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4595 for static tracepoints support.
4597 - GDBserver now supports x86_64 Windows 64-bit debugging.
4599 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4600 it understands register description.
4602 * The --batch flag now disables pagination and queries.
4604 * X86 general purpose registers
4606 GDB now supports reading/writing byte, word and double-word x86
4607 general purpose registers directly. This means you can use, say,
4608 $ah or $ax to refer, respectively, to the byte register AH and
4609 16-bit word register AX that are actually portions of the 32-bit
4610 register EAX or 64-bit register RAX.
4612 * The `commands' command now accepts a range of breakpoints to modify.
4613 A plain `commands' following a command that creates multiple
4614 breakpoints affects all the breakpoints set by that command. This
4615 applies to breakpoints set by `rbreak', and also applies when a
4616 single `break' command creates multiple breakpoints (e.g.,
4617 breakpoints on overloaded c++ functions).
4619 * The `rbreak' command now accepts a filename specification as part of
4620 its argument, limiting the functions selected by the regex to those
4621 in the specified file.
4623 * Support for remote debugging Windows and SymbianOS shared libraries
4624 from Unix hosts has been improved. Non Windows GDB builds now can
4625 understand target reported file names that follow MS-DOS based file
4626 system semantics, such as file names that include drive letters and
4627 use the backslash character as directory separator. This makes it
4628 possible to transparently use the "set sysroot" and "set
4629 solib-search-path" on Unix hosts to point as host copies of the
4630 target's shared libraries. See the new command "set
4631 target-file-system-kind" described below, and the "Commands to
4632 specify files" section in the user manual for more information.
4636 eval template, expressions...
4637 Convert the values of one or more expressions under the control
4638 of the string template to a command line, and call it.
4640 set target-file-system-kind unix|dos-based|auto
4641 show target-file-system-kind
4642 Set or show the assumed file system kind for target reported file
4645 save breakpoints <filename>
4646 Save all current breakpoint definitions to a file suitable for use
4647 in a later debugging session. To read the saved breakpoint
4648 definitions, use the `source' command.
4650 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4653 info static-tracepoint-markers
4654 Display information about static tracepoint markers in the target.
4656 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4657 Define a static tracepoint by probing a marker at the given
4658 function, line, address, or marker ID.
4662 Enable and disable observer mode.
4664 set may-write-registers on|off
4665 set may-write-memory on|off
4666 set may-insert-breakpoints on|off
4667 set may-insert-tracepoints on|off
4668 set may-insert-fast-tracepoints on|off
4669 set may-interrupt on|off
4670 Set individual permissions for GDB effects on the target. Note that
4671 some of these settings can have undesirable or surprising
4672 consequences, particularly when changed in the middle of a session.
4673 For instance, disabling the writing of memory can prevent
4674 breakpoints from being inserted, cause single-stepping to fail, or
4675 even crash your program, if you disable after breakpoints have been
4676 inserted. However, GDB should not crash.
4678 set record memory-query on|off
4679 show record memory-query
4680 Control whether to stop the inferior if memory changes caused
4681 by an instruction cannot be recorded.
4686 The disassemble command now supports "start,+length" form of two arguments.
4690 ** GDB now provides a new directory location, called the python directory,
4691 where Python scripts written for GDB can be installed. The location
4692 of that directory is <data-directory>/python, where <data-directory>
4693 is the GDB data directory. For more details, see section `Scripting
4694 GDB using Python' in the manual.
4696 ** The GDB Python API now has access to breakpoints, symbols, symbol
4697 tables, program spaces, inferiors, threads and frame's code blocks.
4698 Additionally, GDB Parameters can now be created from the API, and
4699 manipulated via set/show in the CLI.
4701 ** New functions gdb.target_charset, gdb.target_wide_charset,
4702 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4704 ** New exception gdb.GdbError.
4706 ** Pretty-printers are now also looked up in the current program space.
4708 ** Pretty-printers can now be individually enabled and disabled.
4710 ** GDB now looks for names of Python scripts to auto-load in a
4711 special section named `.debug_gdb_scripts', in addition to looking
4712 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4714 * Tracepoint actions were unified with breakpoint commands. In particular,
4715 there are no longer differences in "info break" output for breakpoints and
4716 tracepoints and the "commands" command can be used for both tracepoints and
4717 regular breakpoints.
4721 ARM Symbian arm*-*-symbianelf*
4723 * D language support.
4724 GDB now supports debugging programs written in the D programming
4727 * GDB now supports the extended ptrace interface for PowerPC which is
4728 available since Linux kernel version 2.6.34. This automatically enables
4729 any hardware breakpoints and additional hardware watchpoints available in
4730 the processor. The old ptrace interface exposes just one hardware
4731 watchpoint and no hardware breakpoints.
4733 * GDB is now able to use the Data Value Compare (DVC) register available on
4734 embedded PowerPC processors to implement in hardware simple watchpoint
4735 conditions of the form:
4737 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4739 This works in native GDB running on Linux kernels with the extended ptrace
4740 interface mentioned above.
4742 *** Changes in GDB 7.1
4746 ** Namespace Support
4748 GDB now supports importing of namespaces in C++. This enables the
4749 user to inspect variables from imported namespaces. Support for
4750 namepace aliasing has also been added. So, if a namespace is
4751 aliased in the current scope (e.g. namepace C=A; ) the user can
4752 print variables using the alias (e.g. (gdb) print C::x).
4756 All known bugs relating to the printing of virtual base class were
4757 fixed. It is now possible to call overloaded static methods using a
4762 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
4763 and reinterpret_cast<> are now handled by the C++ expression parser.
4767 Xilinx MicroBlaze microblaze-*-*
4772 Xilinx MicroBlaze microblaze
4775 * Multi-program debugging.
4777 GDB now has support for multi-program (a.k.a. multi-executable or
4778 multi-exec) debugging. This allows for debugging multiple inferiors
4779 simultaneously each running a different program under the same GDB
4780 session. See "Debugging Multiple Inferiors and Programs" in the
4781 manual for more information. This implied some user visible changes
4782 in the multi-inferior support. For example, "info inferiors" now
4783 lists inferiors that are not running yet or that have exited
4784 already. See also "New commands" and "New options" below.
4786 * New tracing features
4788 GDB's tracepoint facility now includes several new features:
4790 ** Trace state variables
4792 GDB tracepoints now include support for trace state variables, which
4793 are variables managed by the target agent during a tracing
4794 experiment. They are useful for tracepoints that trigger each
4795 other, so for instance one tracepoint can count hits in a variable,
4796 and then a second tracepoint has a condition that is true when the
4797 count reaches a particular value. Trace state variables share the
4798 $-syntax of GDB convenience variables, and can appear in both
4799 tracepoint actions and condition expressions. Use the "tvariable"
4800 command to create, and "info tvariables" to view; see "Trace State
4801 Variables" in the manual for more detail.
4805 GDB now includes an option for defining fast tracepoints, which
4806 targets may implement more efficiently, such as by installing a jump
4807 into the target agent rather than a trap instruction. The resulting
4808 speedup can be by two orders of magnitude or more, although the
4809 tradeoff is that some program locations on some target architectures
4810 might not allow fast tracepoint installation, for instance if the
4811 instruction to be replaced is shorter than the jump. To request a
4812 fast tracepoint, use the "ftrace" command, with syntax identical to
4813 the regular trace command.
4815 ** Disconnected tracing
4817 It is now possible to detach GDB from the target while it is running
4818 a trace experiment, then reconnect later to see how the experiment
4819 is going. In addition, a new variable disconnected-tracing lets you
4820 tell the target agent whether to continue running a trace if the
4821 connection is lost unexpectedly.
4825 GDB now has the ability to save the trace buffer into a file, and
4826 then use that file as a target, similarly to you can do with
4827 corefiles. You can select trace frames, print data that was
4828 collected in them, and use tstatus to display the state of the
4829 tracing run at the moment that it was saved. To create a trace
4830 file, use "tsave <filename>", and to use it, do "target tfile
4833 ** Circular trace buffer
4835 You can ask the target agent to handle the trace buffer as a
4836 circular buffer, discarding the oldest trace frames to make room for
4837 newer ones, by setting circular-trace-buffer to on. This feature may
4838 not be available for all target agents.
4843 The disassemble command, when invoked with two arguments, now requires
4844 the arguments to be comma-separated.
4847 The info variables command now displays variable definitions. Files
4848 which only declare a variable are not shown.
4851 The source command is now capable of sourcing Python scripts.
4852 This feature is dependent on the debugger being build with Python
4855 Related to this enhancement is also the introduction of a new command
4856 "set script-extension" (see below).
4858 * New commands (for set/show, see "New options" below)
4860 record save [<FILENAME>]
4861 Save a file (in core file format) containing the process record
4862 execution log for replay debugging at a later time.
4864 record restore <FILENAME>
4865 Restore the process record execution log that was saved at an
4866 earlier time, for replay debugging.
4868 add-inferior [-copies <N>] [-exec <FILENAME>]
4871 clone-inferior [-copies <N>] [ID]
4872 Make a new inferior ready to execute the same program another
4873 inferior has loaded.
4878 maint info program-spaces
4879 List the program spaces loaded into GDB.
4881 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
4882 show remote interrupt-sequence
4883 Allow the user to select one of ^C, a BREAK signal or BREAK-g
4884 as the sequence to the remote target in order to interrupt the execution.
4885 Ctrl-C is a default. Some system prefers BREAK which is high level of
4886 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
4887 Magic SysRq g. It is BREAK signal and character 'g'.
4889 set remote interrupt-on-connect [on | off]
4890 show remote interrupt-on-connect
4891 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
4892 remote target when gdb connects to it. This is needed when you debug
4895 set remotebreak [on | off]
4897 Deprecated. Use "set/show remote interrupt-sequence" instead.
4899 tvariable $NAME [ = EXP ]
4900 Create or modify a trace state variable.
4903 List trace state variables and their values.
4905 delete tvariable $NAME ...
4906 Delete one or more trace state variables.
4909 Evaluate the given expressions without collecting anything into the
4910 trace buffer. (Valid in tracepoint actions only.)
4912 ftrace FN / FILE:LINE / *ADDR
4913 Define a fast tracepoint at the given function, line, or address.
4915 * New expression syntax
4917 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
4918 GDB now parses 0b101010 identically with 42.
4922 set follow-exec-mode new|same
4923 show follow-exec-mode
4924 Control whether GDB reuses the same inferior across an exec call or
4925 creates a new one. This is useful to be able to restart the old
4926 executable after the inferior having done an exec call.
4928 set default-collect EXPR, ...
4929 show default-collect
4930 Define a list of expressions to be collected at each tracepoint.
4931 This is a useful way to ensure essential items are not overlooked,
4932 such as registers or a critical global variable.
4934 set disconnected-tracing
4935 show disconnected-tracing
4936 If set to 1, the target is instructed to continue tracing if it
4937 loses its connection to GDB. If 0, the target is to stop tracing
4940 set circular-trace-buffer
4941 show circular-trace-buffer
4942 If set to on, the target is instructed to use a circular trace buffer
4943 and discard the oldest trace frames instead of stopping the trace due
4944 to a full trace buffer. If set to off, the trace stops when the buffer
4945 fills up. Some targets may not support this.
4947 set script-extension off|soft|strict
4948 show script-extension
4949 If set to "off", the debugger does not perform any script language
4950 recognition, and all sourced files are assumed to be GDB scripts.
4951 If set to "soft" (the default), files are sourced according to
4952 filename extension, falling back to GDB scripts if the first
4954 If set to "strict", files are sourced according to filename extension.
4956 set ada trust-PAD-over-XVS on|off
4957 show ada trust-PAD-over-XVS
4958 If off, activate a workaround against a bug in the debugging information
4959 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
4960 the GCC sources for more information about the GNAT encoding and
4961 PAD types in particular). It is always safe to set this option to
4962 off, but this introduces a slight performance penalty. The default
4965 * Python API Improvements
4967 ** GDB provides the new class gdb.LazyString. This is useful in
4968 some pretty-printing cases. The new method gdb.Value.lazy_string
4969 provides a simple way to create objects of this type.
4971 ** The fields returned by gdb.Type.fields now have an
4972 `is_base_class' attribute.
4974 ** The new method gdb.Type.range returns the range of an array type.
4976 ** The new method gdb.parse_and_eval can be used to parse and
4977 evaluate an expression.
4979 * New remote packets
4982 Define a trace state variable.
4985 Get the current value of a trace state variable.
4988 Set desired tracing behavior upon disconnection.
4991 Set the trace buffer to be linear or circular.
4994 Get data about the tracepoints currently in use.
4998 Process record now works correctly with hardware watchpoints.
5000 Multiple bug fixes have been made to the mips-irix port, making it
5001 much more reliable. In particular:
5002 - Debugging threaded applications is now possible again. Previously,
5003 GDB would hang while starting the program, or while waiting for
5004 the program to stop at a breakpoint.
5005 - Attaching to a running process no longer hangs.
5006 - An error occurring while loading a core file has been fixed.
5007 - Changing the value of the PC register now works again. This fixes
5008 problems observed when using the "jump" command, or when calling
5009 a function from GDB, or even when assigning a new value to $pc.
5010 - With the "finish" and "return" commands, the return value for functions
5011 returning a small array is now correctly printed.
5012 - It is now possible to break on shared library code which gets executed
5013 during a shared library init phase (code executed while executing
5014 their .init section). Previously, the breakpoint would have no effect.
5015 - GDB is now able to backtrace through the signal handler for
5016 non-threaded programs.
5018 PIE (Position Independent Executable) programs debugging is now supported.
5019 This includes debugging execution of PIC (Position Independent Code) shared
5020 libraries although for that, it should be possible to run such libraries as an
5023 *** Changes in GDB 7.0
5025 * GDB now has an interface for JIT compilation. Applications that
5026 dynamically generate code can create symbol files in memory and register
5027 them with GDB. For users, the feature should work transparently, and
5028 for JIT developers, the interface is documented in the GDB manual in the
5029 "JIT Compilation Interface" chapter.
5031 * Tracepoints may now be conditional. The syntax is as for
5032 breakpoints; either an "if" clause appended to the "trace" command,
5033 or the "condition" command is available. GDB sends the condition to
5034 the target for evaluation using the same bytecode format as is used
5035 for tracepoint actions.
5037 * The disassemble command now supports: an optional /r modifier, print the
5038 raw instructions in hex as well as in symbolic form, and an optional /m
5039 modifier to print mixed source+assembly.
5041 * Process record and replay
5043 In a architecture environment that supports ``process record and
5044 replay'', ``process record and replay'' target can record a log of
5045 the process execution, and replay it with both forward and reverse
5048 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5049 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5050 set execution-direction {forward|reverse}, for targets that support
5053 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5054 feature is available with a native GDB running on kernel version
5057 * GDB now has support for multi-byte and wide character sets on the
5058 target. Strings whose character type is wchar_t, char16_t, or
5059 char32_t are now correctly printed. GDB supports wide- and unicode-
5060 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5061 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5062 `printf'. This feature requires iconv to work properly; if your
5063 system does not have a working iconv, GDB can use GNU libiconv. See
5064 the installation instructions for more information.
5066 * GDB now supports automatic retrieval of shared library files from
5067 remote targets. To use this feature, specify a system root that begins
5068 with the `remote:' prefix, either via the `set sysroot' command or via
5069 the `--with-sysroot' configure-time option.
5071 * "info sharedlibrary" now takes an optional regex of libraries to show,
5072 and it now reports if a shared library has no debugging information.
5074 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5075 now complete on file names.
5077 * When completing in expressions, gdb will attempt to limit
5078 completions to allowable structure or union fields, where appropriate.
5079 For instance, consider:
5081 # struct example { int f1; double f2; };
5082 # struct example variable;
5085 If the user types TAB at the end of this command line, the available
5086 completions will be "f1" and "f2".
5088 * Inlined functions are now supported. They show up in backtraces, and
5089 the "step", "next", and "finish" commands handle them automatically.
5091 * GDB now supports the token-splicing (##) and stringification (#)
5092 operators when expanding macros. It also supports variable-arity
5095 * GDB now supports inspecting extra signal information, exported by
5096 the new $_siginfo convenience variable. The feature is currently
5097 implemented on linux ARM, i386 and amd64.
5099 * GDB can now display the VFP floating point registers and NEON vector
5100 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5101 can provide these registers (requires Linux 2.6.30 or later). Remote
5102 and simulator targets may also provide them.
5104 * New remote packets
5107 Search memory for a sequence of bytes.
5110 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5111 operation over reliable transport links. Use of this packet is
5112 controlled by the `set remote noack-packet' command.
5115 Kill the process with the specified process ID. Use this in preference
5116 to `k' when multiprocess protocol extensions are supported.
5119 Obtains additional operating system information
5123 Read or write additional signal information.
5125 * Removed remote protocol undocumented extension
5127 An undocumented extension to the remote protocol's `S' stop reply
5128 packet that permitted the stub to pass a process id was removed.
5129 Remote servers should use the `T' stop reply packet instead.
5131 * GDB now supports multiple function calling conventions according to the
5132 DWARF-2 DW_AT_calling_convention function attribute.
5134 * The SH target utilizes the aforementioned change to distinguish between gcc
5135 and Renesas calling convention. It also adds the new CLI commands
5136 `set/show sh calling-convention'.
5138 * GDB can now read compressed debug sections, as produced by GNU gold
5139 with the --compress-debug-sections=zlib flag.
5141 * 64-bit core files are now supported on AIX.
5143 * Thread switching is now supported on Tru64.
5145 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5146 which will be allocated using malloc later in program execution.
5148 * The qXfer:libraries:read remote protocol packet now allows passing a
5149 list of section offsets.
5151 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5152 conditions handling signals delivered during attach or thread creation
5153 have also been fixed.
5155 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5156 From the user's standpoint, all unqualified instances of True and False
5157 are treated as the standard definitions, regardless of context.
5159 * GDB now parses C++ symbol and type names more flexibly. For
5162 template<typename T> class C { };
5165 GDB will now correctly handle all of:
5167 ptype C<char const *>
5168 ptype C<char const*>
5169 ptype C<const char *>
5170 ptype C<const char*>
5172 * New features in the GDB remote stub, gdbserver
5174 - The "--wrapper" command-line argument tells gdbserver to use a
5175 wrapper program to launch programs for debugging.
5177 - On PowerPC and S/390 targets, it is now possible to use a single
5178 gdbserver executable to debug both 32-bit and 64-bit programs.
5179 (This requires gdbserver itself to be built as a 64-bit executable.)
5181 - gdbserver uses the new noack protocol mode for TCP connections to
5182 reduce communications latency, if also supported and enabled in GDB.
5184 - Support for the sparc64-linux-gnu target is now included in
5187 - The amd64-linux build of gdbserver now supports debugging both
5188 32-bit and 64-bit programs.
5190 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5191 now support hardware watchpoints, and will use them automatically
5196 GDB now has support for scripting using Python. Whether this is
5197 available is determined at configure time.
5199 New GDB commands can now be written in Python.
5201 * Ada tasking support
5203 Ada tasks can now be inspected in GDB. The following commands have
5207 Print the list of Ada tasks.
5209 Print detailed information about task number N.
5211 Print the task number of the current task.
5213 Switch the context of debugging to task number N.
5215 * Support for user-defined prefixed commands. The "define" command can
5216 add new commands to existing prefixes, e.g. "target".
5218 * Multi-inferior, multi-process debugging.
5220 GDB now has generalized support for multi-inferior debugging. See
5221 "Debugging Multiple Inferiors" in the manual for more information.
5222 Although availability still depends on target support, the command
5223 set is more uniform now. The GNU/Linux specific multi-forks support
5224 has been migrated to this new framework. This implied some user
5225 visible changes; see "New commands" and also "Removed commands"
5228 * Target descriptions can now describe the target OS ABI. See the
5229 "Target Description Format" section in the user manual for more
5232 * Target descriptions can now describe "compatible" architectures
5233 to indicate that the target can execute applications for a different
5234 architecture in addition to those for the main target architecture.
5235 See the "Target Description Format" section in the user manual for
5238 * Multi-architecture debugging.
5240 GDB now includes general supports for debugging applications on
5241 hybrid systems that use more than one single processor architecture
5242 at the same time. Each such hybrid architecture still requires
5243 specific support to be added. The only hybrid architecture supported
5244 in this version of GDB is the Cell Broadband Engine.
5246 * GDB now supports integrated debugging of Cell/B.E. applications that
5247 use both the PPU and SPU architectures. To enable support for hybrid
5248 Cell/B.E. debugging, you need to configure GDB to support both the
5249 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5250 --enable-targets configure option.
5252 * Non-stop mode debugging.
5254 For some targets, GDB now supports an optional mode of operation in
5255 which you can examine stopped threads while other threads continue
5256 to execute freely. This is referred to as non-stop mode, with the
5257 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5258 section in the user manual for more information.
5260 To be able to support remote non-stop debugging, a remote stub needs
5261 to implement the non-stop mode remote protocol extensions, as
5262 described in the "Remote Non-Stop" section of the user manual. The
5263 GDB remote stub, gdbserver, has been adjusted to support these
5264 extensions on linux targets.
5266 * New commands (for set/show, see "New options" below)
5268 catch syscall [NAME(S) | NUMBER(S)]
5269 Catch system calls. Arguments, which should be names of system
5270 calls or their numbers, mean catch only those syscalls. Without
5271 arguments, every syscall will be caught. When the inferior issues
5272 any of the specified syscalls, GDB will stop and announce the system
5273 call, both when it is called and when its call returns. This
5274 feature is currently available with a native GDB running on the
5275 Linux Kernel, under the following architectures: x86, x86_64,
5276 PowerPC and PowerPC64.
5278 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5280 Search memory for a sequence of bytes.
5282 maint set python print-stack
5283 maint show python print-stack
5284 Show a stack trace when an error is encountered in a Python script.
5287 Invoke CODE by passing it to the Python interpreter.
5292 These allow macros to be defined, undefined, and listed
5296 Show operating system information about processes.
5299 List the inferiors currently under GDB's control.
5302 Switch focus to inferior number NUM.
5305 Detach from inferior number NUM.
5308 Kill inferior number NUM.
5312 set spu stop-on-load
5313 show spu stop-on-load
5314 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5316 set spu auto-flush-cache
5317 show spu auto-flush-cache
5318 Control whether to automatically flush the software-managed cache
5319 during Cell/B.E. debugging.
5321 set sh calling-convention
5322 show sh calling-convention
5323 Control the calling convention used when calling SH target functions.
5326 show debug timestamp
5327 Control display of timestamps with GDB debugging output.
5329 set disassemble-next-line
5330 show disassemble-next-line
5331 Control display of disassembled source lines or instructions when
5334 set remote noack-packet
5335 show remote noack-packet
5336 Set/show the use of remote protocol QStartNoAckMode packet. See above
5337 under "New remote packets."
5339 set remote query-attached-packet
5340 show remote query-attached-packet
5341 Control use of remote protocol `qAttached' (query-attached) packet.
5343 set remote read-siginfo-object
5344 show remote read-siginfo-object
5345 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5348 set remote write-siginfo-object
5349 show remote write-siginfo-object
5350 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5353 set remote reverse-continue
5354 show remote reverse-continue
5355 Control use of remote protocol 'bc' (reverse-continue) packet.
5357 set remote reverse-step
5358 show remote reverse-step
5359 Control use of remote protocol 'bs' (reverse-step) packet.
5361 set displaced-stepping
5362 show displaced-stepping
5363 Control displaced stepping mode. Displaced stepping is a way to
5364 single-step over breakpoints without removing them from the debuggee.
5365 Also known as "out-of-line single-stepping".
5368 show debug displaced
5369 Control display of debugging info for displaced stepping.
5371 maint set internal-error
5372 maint show internal-error
5373 Control what GDB does when an internal error is detected.
5375 maint set internal-warning
5376 maint show internal-warning
5377 Control what GDB does when an internal warning is detected.
5382 Use a wrapper program to launch programs for debugging.
5384 set multiple-symbols (all|ask|cancel)
5385 show multiple-symbols
5386 The value of this variable can be changed to adjust the debugger behavior
5387 when an expression or a breakpoint location contains an ambiguous symbol
5388 name (an overloaded function name, for instance).
5390 set breakpoint always-inserted
5391 show breakpoint always-inserted
5392 Keep breakpoints always inserted in the target, as opposed to inserting
5393 them when resuming the target, and removing them when the target stops.
5394 This option can improve debugger performance on slow remote targets.
5396 set arm fallback-mode (arm|thumb|auto)
5397 show arm fallback-mode
5398 set arm force-mode (arm|thumb|auto)
5400 These commands control how ARM GDB determines whether instructions
5401 are ARM or Thumb. The default for both settings is auto, which uses
5402 the current CPSR value for instructions without symbols; previous
5403 versions of GDB behaved as if "set arm fallback-mode arm".
5405 set arm unwind-secure-frames
5406 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5408 This can trigger security exceptions when unwinding exception stacks.
5410 set disable-randomization
5411 show disable-randomization
5412 Standalone programs run with the virtual address space randomization enabled
5413 by default on some platforms. This option keeps the addresses stable across
5414 multiple debugging sessions.
5418 Control whether other threads are stopped or not when some thread hits
5423 Requests that asynchronous execution is enabled in the target, if available.
5424 In this case, it's possible to resume target in the background, and interact
5425 with GDB while the target is running. "show target-async" displays the
5426 current state of asynchronous execution of the target.
5428 set target-wide-charset
5429 show target-wide-charset
5430 The target-wide-charset is the name of the character set that GDB
5431 uses when printing characters whose type is wchar_t.
5433 set tcp auto-retry (on|off)
5435 set tcp connect-timeout
5436 show tcp connect-timeout
5437 These commands allow GDB to retry failed TCP connections to a remote stub
5438 with a specified timeout period; this is useful if the stub is launched
5439 in parallel with GDB but may not be ready to accept connections immediately.
5441 set libthread-db-search-path
5442 show libthread-db-search-path
5443 Control list of directories which GDB will search for appropriate
5446 set schedule-multiple (on|off)
5447 show schedule-multiple
5448 Allow GDB to resume all threads of all processes or only threads of
5449 the current process.
5453 Use more aggressive caching for accesses to the stack. This improves
5454 performance of remote debugging (particularly backtraces) without
5455 affecting correctness.
5457 set interactive-mode (on|off|auto)
5458 show interactive-mode
5459 Control whether GDB runs in interactive mode (on) or not (off).
5460 When in interactive mode, GDB waits for the user to answer all
5461 queries. Otherwise, GDB does not wait and assumes the default
5462 answer. When set to auto (the default), GDB determines which
5463 mode to use based on the stdin settings.
5468 For program forks, this is replaced by the new more generic `info
5469 inferiors' command. To list checkpoints, you can still use the
5470 `info checkpoints' command, which was an alias for the `info forks'
5474 Replaced by the new `inferior' command. To switch between
5475 checkpoints, you can still use the `restart' command, which was an
5476 alias for the `fork' command.
5479 This is removed, since some targets don't have a notion of
5480 processes. To switch between processes, you can still use the
5481 `inferior' command using GDB's own inferior number.
5484 For program forks, this is replaced by the new more generic `kill
5485 inferior' command. To delete a checkpoint, you can still use the
5486 `delete checkpoint' command, which was an alias for the `delete
5490 For program forks, this is replaced by the new more generic `detach
5491 inferior' command. To detach a checkpoint, you can still use the
5492 `detach checkpoint' command, which was an alias for the `detach
5495 * New native configurations
5497 x86/x86_64 Darwin i[34567]86-*-darwin*
5499 x86_64 MinGW x86_64-*-mingw*
5503 Lattice Mico32 lm32-*
5504 x86 DICOS i[34567]86-*-dicos*
5505 x86_64 DICOS x86_64-*-dicos*
5508 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5509 (mingw32ce) debugging.
5515 These commands were actually not implemented on any target.
5517 *** Changes in GDB 6.8
5519 * New native configurations
5521 NetBSD/hppa hppa*-*netbsd*
5522 Xtensa GNU/Linux xtensa*-*-linux*
5526 NetBSD/hppa hppa*-*-netbsd*
5527 Xtensa GNU/Linux xtensa*-*-linux*
5529 * Change in command line behavior -- corefiles vs. process ids.
5531 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5532 attaching to process NUMBER fails, GDB no longer attempts to open a
5533 core file named NUMBER. Attaching to a program using the -c option
5534 is no longer supported. Instead, use the '-p' or '--pid' options.
5536 * GDB can now be built as a native debugger for debugging Windows x86
5537 (mingw32) Portable Executable (PE) programs.
5539 * Pending breakpoints no longer change their number when their address
5542 * GDB now supports breakpoints with multiple locations,
5543 including breakpoints on C++ constructors, inside C++ templates,
5544 and in inlined functions.
5546 * GDB's ability to debug optimized code has been improved. GDB more
5547 accurately identifies function bodies and lexical blocks that occupy
5548 more than one contiguous range of addresses.
5550 * Target descriptions can now describe registers for PowerPC.
5552 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5553 registers on PowerPC targets.
5555 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5556 targets even when the libthread_db library is not available.
5558 * The GDB remote stub, gdbserver, now supports the new file transfer
5559 commands (remote put, remote get, and remote delete).
5561 * The GDB remote stub, gdbserver, now supports run and attach in
5562 extended-remote mode.
5564 * hppa*64*-*-hpux11* target broken
5565 The debugger is unable to start a program and fails with the following
5566 error: "Error trying to get information about dynamic linker".
5567 The gdb-6.7 release is also affected.
5569 * GDB now supports the --enable-targets= configure option to allow
5570 building a single GDB executable that supports multiple remote
5571 target architectures.
5573 * GDB now supports debugging C and C++ programs which use the
5574 Decimal Floating Point extension. In addition, the PowerPC target
5575 now has a set of pseudo-registers to inspect decimal float values
5576 stored in two consecutive float registers.
5578 * The -break-insert MI command can optionally create pending
5581 * Improved support for debugging Ada
5582 Many improvements to the Ada language support have been made. These
5584 - Better support for Ada2005 interface types
5585 - Improved handling of arrays and slices in general
5586 - Better support for Taft-amendment types
5587 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5589 - Improved command completion in Ada
5592 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5597 set print frame-arguments (all|scalars|none)
5598 show print frame-arguments
5599 The value of this variable can be changed to control which argument
5600 values should be printed by the debugger when displaying a frame.
5605 Transfer files to and from a remote target, and delete remote files.
5612 Transfer files to and from a remote target, and delete remote files.
5614 * New remote packets
5621 Open, close, read, write, and delete files on the remote system.
5624 Attach to an existing process on the remote system, in extended-remote
5628 Run a new process on the remote system, in extended-remote mode.
5630 *** Changes in GDB 6.7
5632 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5633 bfd, libiberty and opcodes, as revealed by static analysis donated by
5634 Coverity, Inc. (http://scan.coverity.com).
5636 * When looking up multiply-defined global symbols, GDB will now prefer the
5637 symbol definition in the current shared library if it was built using the
5638 -Bsymbolic linker option.
5640 * When the Text User Interface (TUI) is not configured, GDB will now
5641 recognize the -tui command-line option and print a message that the TUI
5644 * The GDB remote stub, gdbserver, now has lower overhead for high
5645 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5647 * GDB for MIPS targets now autodetects whether a remote target provides
5648 32-bit or 64-bit register values.
5650 * Support for C++ member pointers has been improved.
5652 * GDB now understands XML target descriptions, which specify the
5653 target's overall architecture. GDB can read a description from
5654 a local file or over the remote serial protocol.
5656 * Vectors of single-byte data use a new integer type which is not
5657 automatically displayed as character or string data.
5659 * The /s format now works with the print command. It displays
5660 arrays of single-byte integers and pointers to single-byte integers
5663 * Target descriptions can now describe target-specific registers,
5664 for architectures which have implemented the support (currently
5665 only ARM, M68K, and MIPS).
5667 * GDB and the GDB remote stub, gdbserver, now support the XScale
5670 * The GDB remote stub, gdbserver, has been updated to support
5671 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5672 has been rewritten to use the standard GDB remote protocol.
5674 * GDB can now step into C++ functions which are called through thunks.
5676 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5678 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5679 layout. It also supports a TextSeg= and DataSeg= response when only
5680 segment base addresses (rather than offsets) are available.
5682 * The /i format now outputs any trailing branch delay slot instructions
5683 immediately following the last instruction within the count specified.
5685 * The GDB remote protocol "T" stop reply packet now supports a
5686 "library" response. Combined with the new "qXfer:libraries:read"
5687 packet, this response allows GDB to debug shared libraries on targets
5688 where the operating system manages the list of loaded libraries (e.g.
5689 Windows and SymbianOS).
5691 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5692 (DLLs) on Windows and Windows CE targets.
5694 * GDB now supports a faster verification that a .debug file matches its binary
5695 according to its build-id signature, if the signature is present.
5701 Enable or disable hardware flow control (RTS/CTS) on the serial port
5702 when debugging using remote targets.
5704 set mem inaccessible-by-default
5705 show mem inaccessible-by-default
5706 If the target supplies a memory map, for instance via the remote
5707 protocol's "qXfer:memory-map:read" packet, setting this variable
5708 prevents GDB from accessing memory outside the memory map. This
5709 is useful for targets with memory mapped registers or which react
5710 badly to accesses of unmapped address space.
5712 set breakpoint auto-hw
5713 show breakpoint auto-hw
5714 If the target supplies a memory map, for instance via the remote
5715 protocol's "qXfer:memory-map:read" packet, setting this variable
5716 lets GDB use hardware breakpoints automatically for memory regions
5717 where it can not use software breakpoints. This covers both the
5718 "break" command and internal breakpoints used for other commands
5719 including "next" and "finish".
5722 catch exception unhandled
5723 Stop the program execution when Ada exceptions are raised.
5726 Stop the program execution when an Ada assertion failed.
5730 Set an alternate system root for target files. This is a more
5731 general version of "set solib-absolute-prefix", which is now
5732 an alias to "set sysroot".
5735 Provide extended SPU facility status information. This set of
5736 commands is available only when debugging the Cell/B.E. SPU
5739 * New native configurations
5741 OpenBSD/sh sh*-*openbsd*
5744 unset tdesc filename
5746 Use the specified local file as an XML target description, and do
5747 not query the target for its built-in description.
5751 OpenBSD/sh sh*-*-openbsd*
5752 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5753 Toshiba Media Processor mep-elf
5755 * New remote packets
5758 Ignore the specified signals; pass them directly to the debugged program
5759 without stopping other threads or reporting them to GDB.
5761 qXfer:features:read:
5762 Read an XML target description from the target, which describes its
5767 Read or write contents of an spufs file on the target system. These
5768 packets are available only on the Cell/B.E. SPU architecture.
5770 qXfer:libraries:read:
5771 Report the loaded shared libraries. Combined with new "T" packet
5772 response, this packet allows GDB to debug shared libraries on
5773 targets where the operating system manages the list of loaded
5774 libraries (e.g. Windows and SymbianOS).
5778 Support for these obsolete configurations has been removed.
5786 i[34567]86-*-lynxos*
5787 i[34567]86-*-netware*
5788 i[34567]86-*-sco3.2v5*
5789 i[34567]86-*-sco3.2v4*
5791 i[34567]86-*-sysv4.2*
5794 i[34567]86-*-unixware2*
5795 i[34567]86-*-unixware*
5804 * Other removed features
5811 Various m68k-only ROM monitors.
5818 Various Renesas ROM monitors and debugging interfaces for SH and
5823 Support for a Macraigor serial interface to on-chip debugging.
5824 GDB does not directly support the newer parallel or USB
5829 A debug information format. The predecessor to DWARF 2 and
5830 DWARF 3, which are still supported.
5832 Support for the HP aCC compiler on HP-UX/PA-RISC
5834 SOM-encapsulated symbolic debugging information, automatic
5835 invocation of pxdb, and the aCC custom C++ ABI. This does not
5836 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
5837 with aCC can still be debugged on an assembly level.
5839 MIPS ".pdr" sections
5841 A MIPS-specific format used to describe stack frame layout
5842 in debugging information.
5846 GDB could work with an older version of Guile to debug
5847 the interpreter and Scheme programs running in it.
5849 set mips stack-arg-size
5850 set mips saved-gpreg-size
5852 Use "set mips abi" to control parameter passing for MIPS.
5854 *** Changes in GDB 6.6
5859 Cell Broadband Engine SPU spu-elf
5861 * GDB can now be configured as a cross-debugger targeting native Windows
5862 (mingw32) or Cygwin. It can communicate with a remote debugging stub
5863 running on a Windows system over TCP/IP to debug Windows programs.
5865 * The GDB remote stub, gdbserver, has been updated to support Windows and
5866 Cygwin debugging. Both single-threaded and multi-threaded programs are
5869 * The "set trust-readonly-sections" command works again. This command was
5870 broken in GDB 6.3, 6.4, and 6.5.
5872 * The "load" command now supports writing to flash memory, if the remote
5873 stub provides the required support.
5875 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
5876 longer requires symbolic debug information (e.g. DWARF-2).
5881 unset substitute-path
5882 show substitute-path
5883 Manage a list of substitution rules that GDB uses to rewrite the name
5884 of the directories where the sources are located. This can be useful
5885 for instance when the sources were moved to a different location
5886 between compilation and debugging.
5890 Print each CLI command as it is executed. Each command is prefixed with
5891 a number of `+' symbols representing the nesting depth.
5892 The source command now has a `-v' option to enable the same feature.
5896 The ARM Demon monitor support (RDP protocol, "target rdp").
5898 Kernel Object Display, an embedded debugging feature which only worked with
5899 an obsolete version of Cisco IOS.
5901 The 'set download-write-size' and 'show download-write-size' commands.
5903 * New remote packets
5906 Tell a stub about GDB client features, and request remote target features.
5907 The first feature implemented is PacketSize, which allows the target to
5908 specify the size of packets it can handle - to minimize the number of
5909 packets required and improve performance when connected to a remote
5913 Fetch an OS auxilliary vector from the remote stub. This packet is a
5914 more efficient replacement for qPart:auxv:read.
5916 qXfer:memory-map:read:
5917 Fetch a memory map from the remote stub, including information about
5918 RAM, ROM, and flash memory devices.
5923 Erase and program a flash memory device.
5925 * Removed remote packets
5928 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
5929 used it, and only gdbserver implemented it.
5931 *** Changes in GDB 6.5
5935 Renesas M32C/M16C m32c-elf
5937 Morpho Technologies ms1 ms1-elf
5941 init-if-undefined Initialize a convenience variable, but
5942 only if it doesn't already have a value.
5944 The following commands are presently only implemented for native GNU/Linux:
5946 checkpoint Save a snapshot of the program state.
5948 restart <n> Return the program state to a
5949 previously saved state.
5951 info checkpoints List currently saved checkpoints.
5953 delete-checkpoint <n> Delete a previously saved checkpoint.
5955 set|show detach-on-fork Tell gdb whether to detach from a newly
5956 forked process, or to keep debugging it.
5958 info forks List forks of the user program that
5959 are available to be debugged.
5961 fork <n> Switch to debugging one of several
5962 forks of the user program that are
5963 available to be debugged.
5965 delete-fork <n> Delete a fork from the list of forks
5966 that are available to be debugged (and
5967 kill the forked process).
5969 detach-fork <n> Delete a fork from the list of forks
5970 that are available to be debugged (and
5971 allow the process to continue).
5975 Morpho Technologies ms2 ms1-elf
5977 * Improved Windows host support
5979 GDB now builds as a cross debugger hosted on i686-mingw32, including
5980 native console support, and remote communications using either
5981 network sockets or serial ports.
5983 * Improved Modula-2 language support
5985 GDB can now print most types in the Modula-2 syntax. This includes:
5986 basic types, set types, record types, enumerated types, range types,
5987 pointer types and ARRAY types. Procedure var parameters are correctly
5988 printed and hexadecimal addresses and character constants are also
5989 written in the Modula-2 syntax. Best results can be obtained by using
5990 GNU Modula-2 together with the -gdwarf-2 command line option.
5994 The ARM rdi-share module.
5996 The Netware NLM debug server.
5998 *** Changes in GDB 6.4
6000 * New native configurations
6002 OpenBSD/arm arm*-*-openbsd*
6003 OpenBSD/mips64 mips64-*-openbsd*
6007 Morpho Technologies ms1 ms1-elf
6009 * New command line options
6011 --batch-silent As for --batch, but totally silent.
6012 --return-child-result The debugger will exist with the same value
6013 the child (debugged) program exited with.
6014 --eval-command COMMAND, -ex COMMAND
6015 Execute a single GDB CLI command. This may be
6016 specified multiple times and in conjunction
6017 with the --command (-x) option.
6019 * Deprecated commands removed
6021 The following commands, that were deprecated in 2000, have been
6025 set|show arm disassembly-flavor set|show arm disassembler
6026 othernames set arm disassembler
6027 set|show remotedebug set|show debug remote
6028 set|show archdebug set|show debug arch
6029 set|show eventdebug set|show debug event
6032 * New BSD user-level threads support
6034 It is now possible to debug programs using the user-level threads
6035 library on OpenBSD and FreeBSD. Currently supported (target)
6038 FreeBSD/amd64 x86_64-*-freebsd*
6039 FreeBSD/i386 i386-*-freebsd*
6040 OpenBSD/i386 i386-*-openbsd*
6042 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6043 are not yet supported.
6045 * New support for Matsushita MN10300 w/sim added
6046 (Work in progress). mn10300-elf.
6048 * REMOVED configurations and files
6050 VxWorks and the XDR protocol *-*-vxworks
6051 Motorola MCORE mcore-*-*
6052 National Semiconductor NS32000 ns32k-*-*
6054 * New "set print array-indexes" command
6056 After turning this setting "on", GDB prints the index of each element
6057 when displaying arrays. The default is "off" to preserve the previous
6060 * VAX floating point support
6062 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6064 * User-defined command support
6066 In addition to using $arg0..$arg9 for argument passing, it is now possible
6067 to use $argc to determine now many arguments have been passed. See the
6068 section on user-defined commands in the user manual for more information.
6070 *** Changes in GDB 6.3:
6072 * New command line option
6074 GDB now accepts -l followed by a number to set the timeout for remote
6077 * GDB works with GCC -feliminate-dwarf2-dups
6079 GDB now supports a more compact representation of DWARF-2 debug
6080 information using DW_FORM_ref_addr references. These are produced
6081 by GCC with the option -feliminate-dwarf2-dups and also by some
6082 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6083 to use -feliminate-dwarf2-dups.
6085 * Internationalization
6087 When supported by the host system, GDB will be built with
6088 internationalization (libintl). The task of marking up the sources is
6089 continued, we're looking forward to our first translation.
6093 Initial support for debugging programs compiled with the GNAT
6094 implementation of the Ada programming language has been integrated
6095 into GDB. In this release, support is limited to expression evaluation.
6097 * New native configurations
6099 GNU/Linux/m32r m32r-*-linux-gnu
6103 GDB's remote protocol now includes support for the 'p' packet. This
6104 packet is used to fetch individual registers from a remote inferior.
6106 * END-OF-LIFE registers[] compatibility module
6108 GDB's internal register infrastructure has been completely rewritten.
6109 The new infrastructure making possible the implementation of key new
6110 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6113 GDB 6.3 will be the last release to include the registers[]
6114 compatibility module that allowed out-of-date configurations to
6115 continue to work. This change directly impacts the following
6125 powerpc bdm protocol
6127 Unless there is activity to revive these configurations, they will be
6128 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6130 * OBSOLETE configurations and files
6132 Configurations that have been declared obsolete in this release have
6133 been commented out. Unless there is activity to revive these
6134 configurations, the next release of GDB will have their sources
6135 permanently REMOVED.
6144 *** Changes in GDB 6.2.1:
6146 * MIPS `break main; run' gave an heuristic-fence-post warning
6148 When attempting to run even a simple program, a warning about
6149 heuristic-fence-post being hit would be reported. This problem has
6152 * MIPS IRIX 'long double' crashed GDB
6154 When examining a long double variable, GDB would get a segmentation
6155 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6156 IRIX long double values).
6160 A bug in the VAX stack code was causing problems with the "next"
6161 command. This problem has been fixed.
6163 *** Changes in GDB 6.2:
6165 * Fix for ``many threads''
6167 On GNU/Linux systems that use the NPTL threads library, a program
6168 rapidly creating and deleting threads would confuse GDB leading to the
6171 ptrace: No such process.
6172 thread_db_get_info: cannot get thread info: generic error
6174 This problem has been fixed.
6176 * "-async" and "-noasync" options removed.
6178 Support for the broken "-noasync" option has been removed (it caused
6181 * New ``start'' command.
6183 This command runs the program until the beginning of the main procedure.
6185 * New BSD Kernel Data Access Library (libkvm) interface
6187 Using ``target kvm'' it is now possible to debug kernel core dumps and
6188 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6189 platforms. Currently supported (native-only) configurations are:
6191 FreeBSD/amd64 x86_64-*-freebsd*
6192 FreeBSD/i386 i?86-*-freebsd*
6193 NetBSD/i386 i?86-*-netbsd*
6194 NetBSD/m68k m68*-*-netbsd*
6195 NetBSD/sparc sparc-*-netbsd*
6196 OpenBSD/amd64 x86_64-*-openbsd*
6197 OpenBSD/i386 i?86-*-openbsd*
6198 OpenBSD/m68k m68*-openbsd*
6199 OpenBSD/sparc sparc-*-openbsd*
6201 * Signal trampoline code overhauled
6203 Many generic problems with GDB's signal handling code have been fixed.
6204 These include: backtraces through non-contiguous stacks; recognition
6205 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6206 call; backtrace through a signal trampoline; step into and out of
6207 signal handlers; and single-stepping in the signal trampoline.
6209 Please note that kernel bugs are a limiting factor here. These
6210 features have been shown to work on an s390 GNU/Linux system that
6211 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6213 * Cygwin support for DWARF 2 added.
6215 * New native configurations
6217 GNU/Linux/hppa hppa*-*-linux*
6218 OpenBSD/hppa hppa*-*-openbsd*
6219 OpenBSD/m68k m68*-*-openbsd*
6220 OpenBSD/m88k m88*-*-openbsd*
6221 OpenBSD/powerpc powerpc-*-openbsd*
6222 NetBSD/vax vax-*-netbsd*
6223 OpenBSD/vax vax-*-openbsd*
6225 * END-OF-LIFE frame compatibility module
6227 GDB's internal frame infrastructure has been completely rewritten.
6228 The new infrastructure making it possible to support key new features
6229 including DWARF 2 Call Frame Information. To aid in the task of
6230 migrating old configurations to this new infrastructure, a
6231 compatibility module, that allowed old configurations to continue to
6232 work, was also included.
6234 GDB 6.2 will be the last release to include this frame compatibility
6235 module. This change directly impacts the following configurations:
6245 Unless there is activity to revive these configurations, they will be
6246 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6248 * REMOVED configurations and files
6250 Sun 3, running SunOS 3 m68*-*-sunos3*
6251 Sun 3, running SunOS 4 m68*-*-sunos4*
6252 Sun 2, running SunOS 3 m68000-*-sunos3*
6253 Sun 2, running SunOS 4 m68000-*-sunos4*
6254 Motorola 680x0 running LynxOS m68*-*-lynxos*
6255 AT&T 3b1/Unix pc m68*-att-*
6256 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6257 decstation mips-dec-* mips-little-*
6258 riscos mips-*-riscos* mips-*-sysv*
6259 sonymips mips-sony-*
6260 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6262 *** Changes in GDB 6.1.1:
6264 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6266 The TUI (Text-mode User Interface) is now built as part of a default
6267 GDB configuration. It is enabled by either selecting the TUI with the
6268 command line option "-i=tui" or by running the separate "gdbtui"
6269 program. For more information on the TUI, see the manual "Debugging
6272 * Pending breakpoint support (also included in GDB 6.1)
6274 Support has been added to allow you to specify breakpoints in shared
6275 libraries that have not yet been loaded. If a breakpoint location
6276 cannot be found, and the "breakpoint pending" option is set to auto,
6277 GDB queries you if you wish to make the breakpoint pending on a future
6278 shared-library load. If and when GDB resolves the breakpoint symbol,
6279 the pending breakpoint is removed as one or more regular breakpoints
6282 Pending breakpoints are very useful for GCJ Java debugging.
6284 * Fixed ISO-C build problems
6286 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6287 non ISO-C code that stopped them being built using a more strict ISO-C
6288 compiler (e.g., IBM's C compiler).
6290 * Fixed build problem on IRIX 5
6292 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6293 wasn't able to compile compile on an IRIX 5 system.
6295 * Added execute permission to gdb/gdbserver/configure
6297 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6298 permission. This bug would cause configure to fail on a number of
6299 systems (Solaris, IRIX). Ref: server/519.
6301 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6303 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6304 has been updated to use constant array sizes.
6306 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6308 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6309 its generated DWARF Call Frame Info. This encoding was causing GDB to
6310 panic, that panic has been fixed. Ref: gdb/1628.
6312 * Fixed a problem when examining parameters in shared library code.
6314 When examining parameters in optimized shared library code generated
6315 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6316 not available''. GDB now correctly displays the variable's value.
6318 *** Changes in GDB 6.1:
6320 * Removed --with-mmalloc
6322 Support for the mmalloc memory manager has been removed, as it
6323 conflicted with the internal gdb byte cache.
6325 * Changes in AMD64 configurations
6327 The AMD64 target now includes the %cs and %ss registers. As a result
6328 the AMD64 remote protocol has changed; this affects the floating-point
6329 and SSE registers. If you rely on those registers for your debugging,
6330 you should upgrade gdbserver on the remote side.
6332 * Revised SPARC target
6334 The SPARC target has been completely revised, incorporating the
6335 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6336 support for LynxOS and SunOS 4 has been dropped. Calling functions
6337 from within GDB on operating systems with a non-executable stack
6338 (Solaris, OpenBSD) now works.
6342 GDB has a new C++ demangler which does a better job on the mangled
6343 names generated by current versions of g++. It also runs faster, so
6344 with this and other changes gdb should now start faster on large C++
6347 * DWARF 2 Location Expressions
6349 GDB support for location expressions has been extended to support function
6350 arguments and frame bases. Older versions of GDB could crash when they
6353 * C++ nested types and namespaces
6355 GDB's support for nested types and namespaces in C++ has been
6356 improved, especially if you use the DWARF 2 debugging format. (This
6357 is the default for recent versions of GCC on most platforms.)
6358 Specifically, if you have a class "Inner" defined within a class or
6359 namespace "Outer", then GDB realizes that the class's name is
6360 "Outer::Inner", not simply "Inner". This should greatly reduce the
6361 frequency of complaints about not finding RTTI symbols. In addition,
6362 if you are stopped at inside of a function defined within a namespace,
6363 GDB modifies its name lookup accordingly.
6365 * New native configurations
6367 NetBSD/amd64 x86_64-*-netbsd*
6368 OpenBSD/amd64 x86_64-*-openbsd*
6369 OpenBSD/alpha alpha*-*-openbsd*
6370 OpenBSD/sparc sparc-*-openbsd*
6371 OpenBSD/sparc64 sparc64-*-openbsd*
6373 * New debugging protocols
6375 M32R with SDI protocol m32r-*-elf*
6377 * "set prompt-escape-char" command deleted.
6379 The command "set prompt-escape-char" has been deleted. This command,
6380 and its very obscure effect on GDB's prompt, was never documented,
6381 tested, nor mentioned in the NEWS file.
6383 * OBSOLETE configurations and files
6385 Configurations that have been declared obsolete in this release have
6386 been commented out. Unless there is activity to revive these
6387 configurations, the next release of GDB will have their sources
6388 permanently REMOVED.
6390 Sun 3, running SunOS 3 m68*-*-sunos3*
6391 Sun 3, running SunOS 4 m68*-*-sunos4*
6392 Sun 2, running SunOS 3 m68000-*-sunos3*
6393 Sun 2, running SunOS 4 m68000-*-sunos4*
6394 Motorola 680x0 running LynxOS m68*-*-lynxos*
6395 AT&T 3b1/Unix pc m68*-att-*
6396 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6397 decstation mips-dec-* mips-little-*
6398 riscos mips-*-riscos* mips-*-sysv*
6399 sonymips mips-sony-*
6400 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6402 * REMOVED configurations and files
6404 SGI Irix-4.x mips-sgi-irix4 or iris4
6405 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6406 Z8000 simulator z8k-zilog-none or z8ksim
6407 Matsushita MN10200 w/simulator mn10200-*-*
6408 H8/500 simulator h8500-hitachi-hms or h8500hms
6409 HP/PA running BSD hppa*-*-bsd*
6410 HP/PA running OSF/1 hppa*-*-osf*
6411 HP/PA Pro target hppa*-*-pro*
6412 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6413 386BSD i[3456]86-*-bsd*
6414 Sequent family i[3456]86-sequent-sysv4*
6415 i[3456]86-sequent-sysv*
6416 i[3456]86-sequent-bsd*
6417 SPARC running LynxOS sparc-*-lynxos*
6418 SPARC running SunOS 4 sparc-*-sunos4*
6419 Tsqware Sparclet sparclet-*-*
6420 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6422 *** Changes in GDB 6.0:
6426 Support for debugging the Objective-C programming language has been
6427 integrated into GDB.
6429 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6431 DWARF 2's Call Frame Information makes available compiler generated
6432 information that more exactly describes the program's run-time stack.
6433 By using this information, GDB is able to provide more robust stack
6436 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6437 have been updated to use a new backtrace mechanism which includes
6438 DWARF 2 CFI support.
6442 GDB's remote protocol has been extended to include support for hosted
6443 file I/O (where the remote target uses GDB's file system). See GDB's
6444 remote protocol documentation for details.
6446 * All targets using the new architecture framework.
6448 All of GDB's targets have been updated to use the new internal
6449 architecture framework. The way is now open for future GDB releases
6450 to include cross-architecture native debugging support (i386 on amd64,
6453 * GNU/Linux's Thread Local Storage (TLS)
6455 GDB now includes support for for the GNU/Linux implementation of
6456 per-thread variables.
6458 * GNU/Linux's Native POSIX Thread Library (NPTL)
6460 GDB's thread code has been updated to work with either the new
6461 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6463 * Separate debug info.
6465 GDB, in conjunction with BINUTILS, now supports a mechanism for
6466 automatically loading debug information from a separate file. Instead
6467 of shipping full debug and non-debug versions of system libraries,
6468 system integrators can now instead ship just the stripped libraries
6469 and optional debug files.
6471 * DWARF 2 Location Expressions
6473 DWARF 2 Location Expressions allow the compiler to more completely
6474 describe the location of variables (even in optimized code) to the
6477 GDB now includes preliminary support for location expressions (support
6478 for DW_OP_piece is still missing).
6482 A number of long standing bugs that caused GDB to die while starting a
6483 Java application have been fixed. GDB's Java support is now
6484 considered "useable".
6486 * GNU/Linux support for fork, vfork, and exec.
6488 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6489 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6492 * GDB supports logging output to a file
6494 There are two new commands, "set logging" and "show logging", which can be
6495 used to capture GDB's output to a file.
6497 * The meaning of "detach" has changed for gdbserver
6499 The "detach" command will now resume the application, as documented. To
6500 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6503 * d10v, m68hc11 `regs' command deprecated
6505 The `info registers' command has been updated so that it displays the
6506 registers using a format identical to the old `regs' command.
6510 A new command, "maint set profile on/off", has been added. This command can
6511 be used to enable or disable profiling while running GDB, to profile a
6512 session or a set of commands. In addition there is a new configure switch,
6513 "--enable-profiling", which will cause GDB to be compiled with profiling
6514 data, for more informative profiling results.
6516 * Default MI syntax changed to "mi2".
6518 The default MI (machine interface) syntax, enabled by the command line
6519 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6520 "mi1", can be enabled by specifying the option "-i=mi1".
6522 Support for the original "mi0" syntax (included in GDB 5.0) has been
6525 Fix for gdb/192: removed extraneous space when displaying frame level.
6526 Fix for gdb/672: update changelist is now output in mi list format.
6527 Fix for gdb/702: a -var-assign that updates the value now shows up
6528 in a subsequent -var-update.
6530 * New native configurations.
6532 FreeBSD/amd64 x86_64-*-freebsd*
6534 * Multi-arched targets.
6536 HP/PA HPUX11 hppa*-*-hpux*
6537 Renesas M32R/D w/simulator m32r-*-elf*
6539 * OBSOLETE configurations and files
6541 Configurations that have been declared obsolete in this release have
6542 been commented out. Unless there is activity to revive these
6543 configurations, the next release of GDB will have their sources
6544 permanently REMOVED.
6546 Z8000 simulator z8k-zilog-none or z8ksim
6547 Matsushita MN10200 w/simulator mn10200-*-*
6548 H8/500 simulator h8500-hitachi-hms or h8500hms
6549 HP/PA running BSD hppa*-*-bsd*
6550 HP/PA running OSF/1 hppa*-*-osf*
6551 HP/PA Pro target hppa*-*-pro*
6552 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6553 Sequent family i[3456]86-sequent-sysv4*
6554 i[3456]86-sequent-sysv*
6555 i[3456]86-sequent-bsd*
6556 Tsqware Sparclet sparclet-*-*
6557 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6559 * REMOVED configurations and files
6562 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6563 IBM AIX PS/2 i[3456]86-*-aix
6564 i386 running Mach 3.0 i[3456]86-*-mach3*
6565 i386 running Mach i[3456]86-*-mach*
6566 i386 running OSF/1 i[3456]86-*osf1mk*
6567 HP/Apollo 68k Family m68*-apollo*-sysv*,
6569 m68*-hp-bsd*, m68*-hp-hpux*
6570 Argonaut Risc Chip (ARC) arc-*-*
6571 Mitsubishi D30V d30v-*-*
6572 Fujitsu FR30 fr30-*-elf*
6573 OS/9000 i[34]86-*-os9k
6574 I960 with MON960 i960-*-coff
6576 * MIPS $fp behavior changed
6578 The convenience variable $fp, for the MIPS, now consistently returns
6579 the address of the current frame's base. Previously, depending on the
6580 context, $fp could refer to either $sp or the current frame's base
6581 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6582 The GNU Source-Level Debugger''.
6584 *** Changes in GDB 5.3:
6586 * GNU/Linux shared library multi-threaded performance improved.
6588 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6589 `/proc', in preference to `ptrace' for memory reads. This may result
6590 in an improvement in the start-up time of multi-threaded, shared
6591 library applications when run under GDB. One GDB user writes: ``loads
6592 shared libs like mad''.
6594 * ``gdbserver'' now supports multi-threaded applications on some targets
6596 Support for debugging multi-threaded applications which use
6597 the GNU/Linux LinuxThreads package has been added for
6598 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6599 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6601 * GDB now supports C/C++ preprocessor macros.
6603 GDB now expands preprocessor macro invocations in C/C++ expressions,
6604 and provides various commands for showing macro definitions and how
6607 The new command `macro expand EXPRESSION' expands any macro
6608 invocations in expression, and shows the result.
6610 The new command `show macro MACRO-NAME' shows the definition of the
6611 macro named MACRO-NAME, and where it was defined.
6613 Most compilers don't include information about macros in the debugging
6614 information by default. In GCC 3.1, for example, you need to compile
6615 your program with the options `-gdwarf-2 -g3'. If the macro
6616 information is present in the executable, GDB will read it.
6618 * Multi-arched targets.
6620 DEC Alpha (partial) alpha*-*-*
6621 DEC VAX (partial) vax-*-*
6623 National Semiconductor NS32000 (partial) ns32k-*-*
6624 Motorola 68000 (partial) m68k-*-*
6625 Motorola MCORE mcore-*-*
6629 Fujitsu FRV architecture added by Red Hat frv*-*-*
6632 * New native configurations
6634 Alpha NetBSD alpha*-*-netbsd*
6635 SH NetBSD sh*-*-netbsdelf*
6636 MIPS NetBSD mips*-*-netbsd*
6637 UltraSPARC NetBSD sparc64-*-netbsd*
6639 * OBSOLETE configurations and files
6641 Configurations that have been declared obsolete in this release have
6642 been commented out. Unless there is activity to revive these
6643 configurations, the next release of GDB will have their sources
6644 permanently REMOVED.
6646 Mitsubishi D30V d30v-*-*
6647 OS/9000 i[34]86-*-os9k
6648 IBM AIX PS/2 i[3456]86-*-aix
6649 Fujitsu FR30 fr30-*-elf*
6650 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6651 Argonaut Risc Chip (ARC) arc-*-*
6652 i386 running Mach 3.0 i[3456]86-*-mach3*
6653 i386 running Mach i[3456]86-*-mach*
6654 i386 running OSF/1 i[3456]86-*osf1mk*
6655 HP/Apollo 68k Family m68*-apollo*-sysv*,
6657 m68*-hp-bsd*, m68*-hp-hpux*
6658 I960 with MON960 i960-*-coff
6660 * OBSOLETE languages
6662 CHILL, a Pascal like language used by telecommunications companies.
6664 * REMOVED configurations and files
6666 AMD 29k family via UDI a29k-amd-udi, udi29k
6667 A29K VxWorks a29k-*-vxworks
6668 AMD 29000 embedded, using EBMON a29k-none-none
6669 AMD 29000 embedded with COFF a29k-none-coff
6670 AMD 29000 embedded with a.out a29k-none-aout
6672 testsuite/gdb.hp/gdb.threads-hp/ directory
6674 * New command "set max-user-call-depth <nnn>"
6676 This command allows the user to limit the call depth of user-defined
6677 commands. The default is 1024.
6679 * Changes in FreeBSD/i386 native debugging.
6681 Support for the "generate-core-file" has been added.
6683 * New commands "dump", "append", and "restore".
6685 These commands allow data to be copied from target memory
6686 to a bfd-format or binary file (dump and append), and back
6687 from a file into memory (restore).
6689 * Improved "next/step" support on multi-processor Alpha Tru64.
6691 The previous single-step mechanism could cause unpredictable problems,
6692 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6693 of a software single-step mechanism prevents this.
6695 *** Changes in GDB 5.2.1:
6703 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6704 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6705 Fix, by Joel Brobecker imported from mainline.
6707 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6708 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6709 Fix, by Fred Fish, imported from mainline.
6711 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6712 Surprisingly enough, it works now.
6713 By Michal Ludvig, imported from mainline.
6715 i386 hardware watchpoint support:
6716 avoid misses on second run for some targets.
6717 By Pierre Muller, imported from mainline.
6719 *** Changes in GDB 5.2:
6721 * New command "set trust-readonly-sections on[off]".
6723 This command is a hint that tells gdb that read-only sections
6724 really are read-only (ie. that their contents will not change).
6725 In this mode, gdb will go to the object file rather than the
6726 target to read memory from read-only sections (such as ".text").
6727 This can be a significant performance improvement on some
6728 (notably embedded) targets.
6730 * New command "generate-core-file" (or "gcore").
6732 This new gdb command allows the user to drop a core file of the child
6733 process state at any time. So far it's been implemented only for
6734 GNU/Linux and Solaris, but should be relatively easily ported to other
6735 hosts. Argument is core file name (defaults to core.<pid>).
6737 * New command line option
6739 GDB now accepts --pid or -p followed by a process id.
6741 * Change in command line behavior -- corefiles vs. process ids.
6743 There is a subtle behavior in the way in which GDB handles
6744 command line arguments. The first non-flag argument is always
6745 a program to debug, but the second non-flag argument may either
6746 be a corefile or a process id. Previously, GDB would attempt to
6747 open the second argument as a corefile, and if that failed, would
6748 issue a superfluous error message and then attempt to attach it as
6749 a process. Now, if the second argument begins with a non-digit,
6750 it will be treated as a corefile. If it begins with a digit,
6751 GDB will attempt to attach it as a process, and if no such process
6752 is found, will then attempt to open it as a corefile.
6754 * Changes in ARM configurations.
6756 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6757 configuration is fully multi-arch.
6759 * New native configurations
6761 ARM NetBSD arm*-*-netbsd*
6762 x86 OpenBSD i[3456]86-*-openbsd*
6763 AMD x86-64 running GNU/Linux x86_64-*-linux-*
6764 Sparc64 running FreeBSD sparc64-*-freebsd*
6768 Sanyo XStormy16 xstormy16-elf
6770 * OBSOLETE configurations and files
6772 Configurations that have been declared obsolete in this release have
6773 been commented out. Unless there is activity to revive these
6774 configurations, the next release of GDB will have their sources
6775 permanently REMOVED.
6777 AMD 29k family via UDI a29k-amd-udi, udi29k
6778 A29K VxWorks a29k-*-vxworks
6779 AMD 29000 embedded, using EBMON a29k-none-none
6780 AMD 29000 embedded with COFF a29k-none-coff
6781 AMD 29000 embedded with a.out a29k-none-aout
6783 testsuite/gdb.hp/gdb.threads-hp/ directory
6785 * REMOVED configurations and files
6787 TI TMS320C80 tic80-*-*
6789 PowerPC Solaris powerpcle-*-solaris*
6790 PowerPC Windows NT powerpcle-*-cygwin32
6791 PowerPC Netware powerpc-*-netware*
6792 Harris/CXUX m88k m88*-harris-cxux*
6793 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6794 ns32k-utek-sysv* ns32k-utek-*
6795 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6796 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6797 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6798 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6799 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
6801 * Changes to command line processing
6803 The new `--args' feature can be used to specify command-line arguments
6804 for the inferior from gdb's command line.
6806 * Changes to key bindings
6808 There is a new `operate-and-get-next' function bound to `C-o'.
6810 *** Changes in GDB 5.1.1
6812 Fix compile problem on DJGPP.
6814 Fix a problem with floating-point registers on the i386 being
6817 Fix to stop GDB crashing on .debug_str debug info.
6819 Numerous documentation fixes.
6821 Numerous testsuite fixes.
6823 *** Changes in GDB 5.1:
6825 * New native configurations
6827 Alpha FreeBSD alpha*-*-freebsd*
6828 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
6829 MIPS GNU/Linux mips*-*-linux*
6830 MIPS SGI Irix 6.x mips*-sgi-irix6*
6831 ia64 AIX ia64-*-aix*
6832 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
6836 Motorola 68HC11 and 68HC12 m68hc11-elf
6838 UltraSparc running GNU/Linux sparc64-*-linux*
6840 * OBSOLETE configurations and files
6842 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
6843 Harris/CXUX m88k m88*-harris-cxux*
6844 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
6845 ns32k-utek-sysv* ns32k-utek-*
6846 TI TMS320C80 tic80-*-*
6848 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
6849 PowerPC Solaris powerpcle-*-solaris*
6850 PowerPC Windows NT powerpcle-*-cygwin32
6851 PowerPC Netware powerpc-*-netware*
6852 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
6853 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
6854 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
6855 Apple Macintosh (MPW) host N/A
6857 stuff.c (Program to stuff files into a specially prepared space in kdb)
6858 kdb-start.c (Main loop for the standalone kernel debugger)
6860 Configurations that have been declared obsolete in this release have
6861 been commented out. Unless there is activity to revive these
6862 configurations, the next release of GDB will have their sources
6863 permanently REMOVED.
6865 * REMOVED configurations and files
6867 Altos 3068 m68*-altos-*
6868 Convex c1-*-*, c2-*-*
6870 ARM RISCix arm-*-* (as host)
6874 * GDB has been converted to ISO C.
6876 GDB's source code has been converted to ISO C. In particular, the
6877 sources are fully protoized, and rely on standard headers being
6882 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
6884 * The MI enabled by default.
6886 The new machine oriented interface (MI) introduced in GDB 5.0 has been
6887 revised and enabled by default. Packages which use GDB as a debugging
6888 engine behind a UI or another front end are encouraged to switch to
6889 using the GDB/MI interface, instead of the old annotations interface
6890 which is now deprecated.
6892 * Support for debugging Pascal programs.
6894 GDB now includes support for debugging Pascal programs. The following
6895 main features are supported:
6897 - Pascal-specific data types such as sets;
6899 - automatic recognition of Pascal sources based on file-name
6902 - Pascal-style display of data types, variables, and functions;
6904 - a Pascal expression parser.
6906 However, some important features are not yet supported.
6908 - Pascal string operations are not supported at all;
6910 - there are some problems with boolean types;
6912 - Pascal type hexadecimal constants are not supported
6913 because they conflict with the internal variables format;
6915 - support for Pascal objects and classes is not full yet;
6917 - unlike Pascal, GDB is case-sensitive for symbol names.
6919 * Changes in completion.
6921 Commands such as `shell', `run' and `set args', which pass arguments
6922 to inferior programs, now complete on file names, similar to what
6923 users expect at the shell prompt.
6925 Commands which accept locations, such as `disassemble', `print',
6926 `breakpoint', `until', etc. now complete on filenames as well as
6927 program symbols. Thus, if you type "break foob TAB", and the source
6928 files linked into the programs include `foobar.c', that file name will
6929 be one of the candidates for completion. However, file names are not
6930 considered for completion after you typed a colon that delimits a file
6931 name from a name of a function in that file, as in "break foo.c:bar".
6933 `set demangle-style' completes on available demangling styles.
6935 * New platform-independent commands:
6937 It is now possible to define a post-hook for a command as well as a
6938 hook that runs before the command. For more details, see the
6939 documentation of `hookpost' in the GDB manual.
6941 * Changes in GNU/Linux native debugging.
6943 Support for debugging multi-threaded programs has been completely
6944 revised for all platforms except m68k and sparc. You can now debug as
6945 many threads as your system allows you to have.
6947 Attach/detach is supported for multi-threaded programs.
6949 Support for SSE registers was added for x86. This doesn't work for
6950 multi-threaded programs though.
6952 * Changes in MIPS configurations.
6954 Multi-arch support is enabled for all MIPS configurations.
6956 GDB can now be built as native debugger on SGI Irix 6.x systems for
6957 debugging n32 executables. (Debugging 64-bit executables is not yet
6960 * Unified support for hardware watchpoints in all x86 configurations.
6962 Most (if not all) native x86 configurations support hardware-assisted
6963 breakpoints and watchpoints in a unified manner. This support
6964 implements debug register sharing between watchpoints, which allows to
6965 put a virtually infinite number of watchpoints on the same address,
6966 and also supports watching regions up to 16 bytes with several debug
6969 The new maintenance command `maintenance show-debug-regs' toggles
6970 debugging print-outs in functions that insert, remove, and test
6971 watchpoints and hardware breakpoints.
6973 * Changes in the DJGPP native configuration.
6975 New command ``info dos sysinfo'' displays assorted information about
6976 the CPU, OS, memory, and DPMI server.
6978 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
6979 display information about segment descriptors stored in GDT, LDT, and
6982 New commands ``info dos pde'' and ``info dos pte'' display entries
6983 from Page Directory and Page Tables (for now works with CWSDPMI only).
6984 New command ``info dos address-pte'' displays the Page Table entry for
6985 a given linear address.
6987 GDB can now pass command lines longer than 126 characters to the
6988 program being debugged (requires an update to the libdbg.a library
6989 which is part of the DJGPP development kit).
6991 DWARF2 debug info is now supported.
6993 It is now possible to `step' and `next' through calls to `longjmp'.
6995 * Changes in documentation.
6997 All GDB documentation was converted to GFDL, the GNU Free
6998 Documentation License.
7000 Tracepoints-related commands are now fully documented in the GDB
7003 TUI, the Text-mode User Interface, is now documented in the manual.
7005 Tracepoints-related commands are now fully documented in the GDB
7008 The "GDB Internals" manual now has an index. It also includes
7009 documentation of `ui_out' functions, GDB coding standards, x86
7010 hardware watchpoints, and memory region attributes.
7012 * GDB's version number moved to ``version.in''
7014 The Makefile variable VERSION has been replaced by the file
7015 ``version.in''. People creating GDB distributions should update the
7016 contents of this file.
7020 GUD support is now a standard part of the EMACS distribution.
7022 *** Changes in GDB 5.0:
7024 * Improved support for debugging FP programs on x86 targets
7026 Unified and much-improved support for debugging floating-point
7027 programs on all x86 targets. In particular, ``info float'' now
7028 displays the FP registers in the same format on all x86 targets, with
7029 greater level of detail.
7031 * Improvements and bugfixes in hardware-assisted watchpoints
7033 It is now possible to watch array elements, struct members, and
7034 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7035 on x86 targets no longer erroneously trigger when the address is
7038 * Improvements in the native DJGPP version of GDB
7040 The distribution now includes all the scripts and auxiliary files
7041 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7042 machines ``out of the box''.
7044 The DJGPP version can now debug programs that use signals. It is
7045 possible to catch signals that happened in the debuggee, deliver
7046 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7047 would kill the program being debugged.) Programs that hook hardware
7048 interrupts (keyboard, timer, etc.) can also be debugged.
7050 It is now possible to debug DJGPP programs that redirect their
7051 standard handles or switch them to raw (as opposed to cooked) mode, or
7052 even close them. The command ``run < foo > bar'' works as expected,
7053 and ``info terminal'' reports useful information about the debuggee's
7054 terminal, including raw/cooked mode, redirection, etc.
7056 The DJGPP version now uses termios functions for console I/O, which
7057 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7060 DOS-style file names with drive letters are now fully supported by
7063 It is now possible to debug DJGPP programs that switch their working
7064 directory. It is also possible to rerun the debuggee any number of
7065 times without restarting GDB; thus, you can use the same setup,
7066 breakpoints, etc. for many debugging sessions.
7068 * New native configurations
7070 ARM GNU/Linux arm*-*-linux*
7071 PowerPC GNU/Linux powerpc-*-linux*
7075 Motorola MCore mcore-*-*
7076 x86 VxWorks i[3456]86-*-vxworks*
7077 PowerPC VxWorks powerpc-*-vxworks*
7078 TI TMS320C80 tic80-*-*
7080 * OBSOLETE configurations
7082 Altos 3068 m68*-altos-*
7083 Convex c1-*-*, c2-*-*
7085 ARM RISCix arm-*-* (as host)
7088 Configurations that have been declared obsolete will be commented out,
7089 but the code will be left in place. If there is no activity to revive
7090 these configurations before the next release of GDB, the sources will
7091 be permanently REMOVED.
7093 * Gould support removed
7095 Support for the Gould PowerNode and NP1 has been removed.
7097 * New features for SVR4
7099 On SVR4 native platforms (such as Solaris), if you attach to a process
7100 without first loading a symbol file, GDB will now attempt to locate and
7101 load symbols from the running process's executable file.
7103 * Many C++ enhancements
7105 C++ support has been greatly improved. Overload resolution now works properly
7106 in almost all cases. RTTI support is on the way.
7108 * Remote targets can connect to a sub-program
7110 A popen(3) style serial-device has been added. This device starts a
7111 sub-process (such as a stand-alone simulator) and then communicates
7112 with that. The sub-program to run is specified using the syntax
7113 ``|<program> <args>'' vis:
7115 (gdb) set remotedebug 1
7116 (gdb) target extended-remote |mn10300-elf-sim program-args
7118 * MIPS 64 remote protocol
7120 A long standing bug in the mips64 remote protocol where by GDB
7121 expected certain 32 bit registers (ex SR) to be transfered as 32
7122 instead of 64 bits has been fixed.
7124 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7125 added to provide backward compatibility with older versions of GDB.
7127 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7129 The command ``set remotebinarydownload'' command has been replaced by
7130 ``set remote X-packet''. Other commands in ``set remote'' family
7131 include ``set remote P-packet''.
7133 * Breakpoint commands accept ranges.
7135 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7136 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7137 ``tracepoint passcount'' also accepts a range of tracepoints.
7139 * ``apropos'' command added.
7141 The ``apropos'' command searches through command names and
7142 documentation strings, printing out matches, making it much easier to
7143 try to find a command that does what you are looking for.
7147 A new machine oriented interface (MI) has been added to GDB. This
7148 interface is designed for debug environments running GDB as a separate
7149 process. This is part of the long term libGDB project. See the
7150 "GDB/MI" chapter of the GDB manual for further information. It can be
7151 enabled by configuring with:
7153 .../configure --enable-gdbmi
7155 *** Changes in GDB-4.18:
7157 * New native configurations
7159 HP-UX 10.20 hppa*-*-hpux10.20
7160 HP-UX 11.x hppa*-*-hpux11.0*
7161 M68K GNU/Linux m68*-*-linux*
7165 Fujitsu FR30 fr30-*-elf*
7166 Intel StrongARM strongarm-*-*
7167 Mitsubishi D30V d30v-*-*
7169 * OBSOLETE configurations
7171 Gould PowerNode, NP1 np1-*-*, pn-*-*
7173 Configurations that have been declared obsolete will be commented out,
7174 but the code will be left in place. If there is no activity to revive
7175 these configurations before the next release of GDB, the sources will
7176 be permanently REMOVED.
7180 As a compatibility experiment, GDB's source files buildsym.h and
7181 buildsym.c have been converted to pure standard C, no longer
7182 containing any K&R compatibility code. We believe that all systems in
7183 use today either come with a standard C compiler, or have a GCC port
7184 available. If this is not true, please report the affected
7185 configuration to bug-gdb@gnu.org immediately. See the README file for
7186 information about getting a standard C compiler if you don't have one
7191 GDB now uses readline 2.2.
7193 * set extension-language
7195 You can now control the mapping between filename extensions and source
7196 languages by using the `set extension-language' command. For instance,
7197 you can ask GDB to treat .c files as C++ by saying
7198 set extension-language .c c++
7199 The command `info extensions' lists all of the recognized extensions
7200 and their associated languages.
7202 * Setting processor type for PowerPC and RS/6000
7204 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7205 you can use the `set processor' command to specify what variant of the
7206 PowerPC family you are debugging. The command
7210 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7211 following PowerPC and RS6000 variants:
7213 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7214 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7216 403GC IBM PowerPC 403GC
7217 505 Motorola PowerPC 505
7218 860 Motorola PowerPC 860 or 850
7219 601 Motorola PowerPC 601
7220 602 Motorola PowerPC 602
7221 603 Motorola/IBM PowerPC 603 or 603e
7222 604 Motorola PowerPC 604 or 604e
7223 750 Motorola/IBM PowerPC 750 or 750
7225 At the moment, this command just tells GDB what to name the
7226 special-purpose processor registers. Since almost all the affected
7227 registers are inaccessible to user-level programs, this command is
7228 only useful for remote debugging in its present form.
7232 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7233 more extensive support for HP-UX. Added features include shared
7234 library support, kernel threads and hardware watchpoints for 11.00,
7235 support for HP's ANSI C and C++ compilers, and a compatibility mode
7236 for xdb and dbx commands.
7240 HP's donation includes the new concept of catchpoints, which is a
7241 generalization of the old catch command. On HP-UX, it is now possible
7242 to catch exec, fork, and vfork, as well as library loading.
7244 This means that the existing catch command has changed; its first
7245 argument now specifies the type of catch to be set up. See the
7246 output of "help catch" for a list of catchpoint types.
7248 * Debugging across forks
7250 On HP-UX, you can choose which process to debug when a fork() happens
7255 HP has donated a curses-based terminal user interface (TUI). To get
7256 it, build with --enable-tui. Although this can be enabled for any
7257 configuration, at present it only works for native HP debugging.
7259 * GDB remote protocol additions
7261 A new protocol packet 'X' that writes binary data is now available.
7262 Default behavior is to try 'X', then drop back to 'M' if the stub
7263 fails to respond. The settable variable `remotebinarydownload'
7264 allows explicit control over the use of 'X'.
7266 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7267 full 64-bit address. The command
7269 set remoteaddresssize 32
7271 can be used to revert to the old behaviour. For existing remote stubs
7272 the change should not be noticed, as the additional address information
7275 In order to assist in debugging stubs, you may use the maintenance
7276 command `packet' to send any text string to the stub. For instance,
7278 maint packet heythere
7280 sends the packet "$heythere#<checksum>". Note that it is very easy to
7281 disrupt a debugging session by sending the wrong packet at the wrong
7284 The compare-sections command allows you to compare section data on the
7285 target to what is in the executable file without uploading or
7286 downloading, by comparing CRC checksums.
7288 * Tracing can collect general expressions
7290 You may now collect general expressions at tracepoints. This requires
7291 further additions to the target-side stub; see tracepoint.c and
7292 doc/agentexpr.texi for further details.
7294 * mask-address variable for Mips
7296 For Mips targets, you may control the zeroing of the upper 32 bits of
7297 a 64-bit address by entering `set mask-address on'. This is mainly
7298 of interest to users of embedded R4xxx and R5xxx processors.
7300 * Higher serial baud rates
7302 GDB's serial code now allows you to specify baud rates 57600, 115200,
7303 230400, and 460800 baud. (Note that your host system may not be able
7304 to achieve all of these rates.)
7308 The i960 configuration now includes an initial implementation of a
7309 builtin simulator, contributed by Jim Wilson.
7312 *** Changes in GDB-4.17:
7314 * New native configurations
7316 Alpha GNU/Linux alpha*-*-linux*
7317 Unixware 2.x i[3456]86-unixware2*
7318 Irix 6.x mips*-sgi-irix6*
7319 PowerPC GNU/Linux powerpc-*-linux*
7320 PowerPC Solaris powerpcle-*-solaris*
7321 Sparc GNU/Linux sparc-*-linux*
7322 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7326 Argonaut Risc Chip (ARC) arc-*-*
7327 Hitachi H8/300S h8300*-*-*
7328 Matsushita MN10200 w/simulator mn10200-*-*
7329 Matsushita MN10300 w/simulator mn10300-*-*
7330 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7331 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7332 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7333 Mitsubishi D10V w/simulator d10v-*-*
7334 Mitsubishi M32R/D w/simulator m32r-*-elf*
7335 Tsqware Sparclet sparclet-*-*
7336 NEC V850 w/simulator v850-*-*
7338 * New debugging protocols
7340 ARM with RDI protocol arm*-*-*
7341 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7342 DDB and LSI variants of PMON protocol mips*-*-*
7343 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7344 PowerPC with SDS protocol powerpc{,le}-*-eabi
7345 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7349 All configurations can now understand and use the DWARF 2 debugging
7350 format. The choice is automatic, if the symbol file contains DWARF 2
7355 GDB now includes basic Java language support. This support is
7356 only useful with Java compilers that produce native machine code.
7358 * solib-absolute-prefix and solib-search-path
7360 For SunOS and SVR4 shared libraries, you may now set the prefix for
7361 loading absolute shared library symbol files, and the search path for
7362 locating non-absolute shared library symbol files.
7364 * Live range splitting
7366 GDB can now effectively debug code for which GCC has performed live
7367 range splitting as part of its optimization. See gdb/doc/LRS for
7368 more details on the expected format of the stabs information.
7372 GDB's support for the GNU Hurd, including thread debugging, has been
7373 updated to work with current versions of the Hurd.
7377 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7378 instruction set. ARM GDB automatically detects when Thumb
7379 instructions are in use, and adjusts disassembly and backtracing
7384 GDB's MIPS target configurations now handle the MIP16 16-bit
7389 GDB now includes support for overlays; if an executable has been
7390 linked such that multiple sections are based at the same address, GDB
7391 will decide which section to use for symbolic info. You can choose to
7392 control the decision manually, using overlay commands, or implement
7393 additional target-side support and use "overlay load-target" to bring
7394 in the overlay mapping. Do "help overlay" for more detail.
7398 The command "info symbol <address>" displays information about
7399 the symbol at the specified address.
7403 The standard remote protocol now includes an extension that allows
7404 asynchronous collection and display of trace data. This requires
7405 extensive support in the target-side debugging stub. Tracing mode
7406 includes a new interaction mode in GDB and new commands: see the
7407 file tracepoint.c for more details.
7411 Configurations for embedded MIPS now include a simulator contributed
7412 by Cygnus Solutions. The simulator supports the instruction sets
7413 of most MIPS variants.
7417 Sparc configurations may now include the ERC32 simulator contributed
7418 by the European Space Agency. The simulator is not built into
7419 Sparc targets by default; configure with --enable-sim to include it.
7423 For target configurations that may include multiple variants of a
7424 basic architecture (such as MIPS and SH), you may now set the
7425 architecture explicitly. "set arch" sets, "info arch" lists
7426 the possible architectures.
7428 *** Changes in GDB-4.16:
7430 * New native configurations
7432 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7433 M68K NetBSD m68k-*-netbsd*
7434 PowerPC AIX 4.x powerpc-*-aix*
7435 PowerPC MacOS powerpc-*-macos*
7436 PowerPC Windows NT powerpcle-*-cygwin32
7437 RS/6000 AIX 4.x rs6000-*-aix4*
7441 ARM with RDP protocol arm-*-*
7442 I960 with MON960 i960-*-coff
7443 MIPS VxWorks mips*-*-vxworks*
7444 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7445 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7447 Matra Sparclet sparclet-*-*
7451 The powerpc-eabi configuration now includes the PSIM simulator,
7452 contributed by Andrew Cagney, with assistance from Mike Meissner.
7453 PSIM is a very elaborate model of the PowerPC, including not only
7454 basic instruction set execution, but also details of execution unit
7455 performance and I/O hardware. See sim/ppc/README for more details.
7459 GDB now works with Solaris 2.5.
7461 * Windows 95/NT native
7463 GDB will now work as a native debugger on Windows 95 and Windows NT.
7464 To build it from source, you must use the "gnu-win32" environment,
7465 which uses a DLL to emulate enough of Unix to run the GNU tools.
7466 Further information, binaries, and sources are available at
7467 ftp.cygnus.com, under pub/gnu-win32.
7469 * dont-repeat command
7471 If a user-defined command includes the command `dont-repeat', then the
7472 command will not be repeated if the user just types return. This is
7473 useful if the command is time-consuming to run, so that accidental
7474 extra keystrokes don't run the same command many times.
7476 * Send break instead of ^C
7478 The standard remote protocol now includes an option to send a break
7479 rather than a ^C to the target in order to interrupt it. By default,
7480 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7482 * Remote protocol timeout
7484 The standard remote protocol includes a new variable `remotetimeout'
7485 that allows you to set the number of seconds before GDB gives up trying
7486 to read from the target. The default value is 2.
7488 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7490 By default GDB will automatically keep track of objects as they are
7491 loaded and unloaded by the dynamic linker. By using the command `set
7492 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7493 when shared library events occur, thus allowing you to set breakpoints
7494 in shared libraries which are explicitly loaded by the inferior.
7496 Note this feature does not work on hpux8. On hpux9 you must link
7497 /usr/lib/end.o into your program. This feature should work
7498 automatically on hpux10.
7500 * Irix 5.x hardware watchpoint support
7502 Irix 5 configurations now support the use of hardware watchpoints.
7504 * Mips protocol "SYN garbage limit"
7506 When debugging a Mips target using the `target mips' protocol, you
7507 may set the number of characters that GDB will ignore by setting
7508 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7509 every character. The default value is 1050.
7511 * Recording and replaying remote debug sessions
7513 If you set `remotelogfile' to the name of a file, gdb will write to it
7514 a recording of a remote debug session. This recording may then be
7515 replayed back to gdb using "gdbreplay". See gdbserver/README for
7516 details. This is useful when you have a problem with GDB while doing
7517 remote debugging; you can make a recording of the session and send it
7518 to someone else, who can then recreate the problem.
7520 * Speedups for remote debugging
7522 GDB includes speedups for downloading and stepping MIPS systems using
7523 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7524 and more efficient S-record downloading.
7526 * Memory use reductions and statistics collection
7528 GDB now uses less memory and reports statistics about memory usage.
7529 Try the `maint print statistics' command, for example.
7531 *** Changes in GDB-4.15:
7533 * Psymtabs for XCOFF
7535 The symbol reader for AIX GDB now uses partial symbol tables. This
7536 can greatly improve startup time, especially for large executables.
7538 * Remote targets use caching
7540 Remote targets now use a data cache to speed up communication with the
7541 remote side. The data cache could lead to incorrect results because
7542 it doesn't know about volatile variables, thus making it impossible to
7543 debug targets which use memory mapped I/O devices. `set remotecache
7544 off' turns the data cache off.
7546 * Remote targets may have threads
7548 The standard remote protocol now includes support for multiple threads
7549 in the target system, using new protocol commands 'H' and 'T'. See
7550 gdb/remote.c for details.
7554 If GDB is configured with `--enable-netrom', then it will include
7555 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7556 acts as though it is a bank of ROM on the target board, but you can
7557 write into it over the network. GDB's support consists only of
7558 support for fast loading into the emulated ROM; to debug, you must use
7559 another protocol, such as standard remote protocol. The usual
7560 sequence is something like
7562 target nrom <netrom-hostname>
7564 target remote <netrom-hostname>:1235
7568 GDB now includes support for the Apple Macintosh, as a host only. It
7569 may be run as either an MPW tool or as a standalone application, and
7570 it can debug through the serial port. All the usual GDB commands are
7571 available, but to the target command, you must supply "serial" as the
7572 device type instead of "/dev/ttyXX". See mpw-README in the main
7573 directory for more information on how to build. The MPW configuration
7574 scripts */mpw-config.in support only a few targets, and only the
7575 mips-idt-ecoff target has been tested.
7579 GDB configuration now uses autoconf. This is not user-visible,
7580 but does simplify configuration and building.
7584 GDB now supports hpux10.
7586 *** Changes in GDB-4.14:
7588 * New native configurations
7590 x86 FreeBSD i[345]86-*-freebsd
7591 x86 NetBSD i[345]86-*-netbsd
7592 NS32k NetBSD ns32k-*-netbsd
7593 Sparc NetBSD sparc-*-netbsd
7597 A29K VxWorks a29k-*-vxworks
7598 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7599 CPU32 EST-300 emulator m68*-*-est*
7600 PowerPC ELF powerpc-*-elf
7603 * Alpha OSF/1 support for procfs
7605 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7606 possible to attach to running processes. As the mounting of the /proc
7607 filesystem is optional on the Alpha, GDB automatically determines
7608 the availability of /proc during startup. This can lead to problems
7609 if /proc is unmounted after GDB has been started.
7611 * Arguments to user-defined commands
7613 User commands may accept up to 10 arguments separated by whitespace.
7614 Arguments are accessed within the user command via $arg0..$arg9. A
7617 print $arg0 + $arg1 + $arg2
7619 To execute the command use:
7622 Defines the command "adder" which prints the sum of its three arguments.
7623 Note the arguments are text substitutions, so they may reference variables,
7624 use complex expressions, or even perform inferior function calls.
7626 * New `if' and `while' commands
7628 This makes it possible to write more sophisticated user-defined
7629 commands. Both commands take a single argument, which is the
7630 expression to evaluate, and must be followed by the commands to
7631 execute, one per line, if the expression is nonzero, the list being
7632 terminated by the word `end'. The `if' command list may include an
7633 `else' word, which causes the following commands to be executed only
7634 if the expression is zero.
7636 * Fortran source language mode
7638 GDB now includes partial support for Fortran 77. It will recognize
7639 Fortran programs and can evaluate a subset of Fortran expressions, but
7640 variables and functions may not be handled correctly. GDB will work
7641 with G77, but does not yet know much about symbols emitted by other
7644 * Better HPUX support
7646 Most debugging facilities now work on dynamic executables for HPPAs
7647 running hpux9 or later. You can attach to running dynamically linked
7648 processes, but by default the dynamic libraries will be read-only, so
7649 for instance you won't be able to put breakpoints in them. To change
7650 that behavior do the following before running the program:
7656 This will cause the libraries to be mapped private and read-write.
7657 To revert to the normal behavior, do this:
7663 You cannot set breakpoints or examine data in the library until after
7664 the library is loaded if the function/data symbols do not have
7667 GDB can now also read debug symbols produced by the HP C compiler on
7668 HPPAs (sorry, no C++, Fortran or 68k support).
7670 * Target byte order now dynamically selectable
7672 You can choose which byte order to use with a target system, via the
7673 commands "set endian big" and "set endian little", and you can see the
7674 current setting by using "show endian". You can also give the command
7675 "set endian auto", in which case GDB will use the byte order
7676 associated with the executable. Currently, only embedded MIPS
7677 configurations support dynamic selection of target byte order.
7679 * New DOS host serial code
7681 This version uses DPMI interrupts to handle buffered I/O, so you
7682 no longer need to run asynctsr when debugging boards connected to
7685 *** Changes in GDB-4.13:
7687 * New "complete" command
7689 This lists all the possible completions for the rest of the line, if it
7690 were to be given as a command itself. This is intended for use by emacs.
7692 * Trailing space optional in prompt
7694 "set prompt" no longer adds a space for you after the prompt you set. This
7695 allows you to set a prompt which ends in a space or one that does not.
7697 * Breakpoint hit counts
7699 "info break" now displays a count of the number of times the breakpoint
7700 has been hit. This is especially useful in conjunction with "ignore"; you
7701 can ignore a large number of breakpoint hits, look at the breakpoint info
7702 to see how many times the breakpoint was hit, then run again, ignoring one
7703 less than that number, and this will get you quickly to the last hit of
7706 * Ability to stop printing at NULL character
7708 "set print null-stop" will cause GDB to stop printing the characters of
7709 an array when the first NULL is encountered. This is useful when large
7710 arrays actually contain only short strings.
7712 * Shared library breakpoints
7714 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7715 breakpoints in shared libraries before the executable is run.
7717 * Hardware watchpoints
7719 There is a new hardware breakpoint for the watch command for sparclite
7720 targets. See gdb/sparclite/hw_breakpoint.note.
7722 Hardware watchpoints are also now supported under GNU/Linux.
7726 Annotations have been added. These are for use with graphical interfaces,
7727 and are still experimental. Currently only gdba.el uses these.
7729 * Improved Irix 5 support
7731 GDB now works properly with Irix 5.2.
7733 * Improved HPPA support
7735 GDB now works properly with the latest GCC and GAS.
7737 * New native configurations
7739 Sequent PTX4 i[34]86-sequent-ptx4
7740 HPPA running OSF/1 hppa*-*-osf*
7741 Atari TT running SVR4 m68*-*-sysv4*
7742 RS/6000 LynxOS rs6000-*-lynxos*
7746 OS/9000 i[34]86-*-os9k
7747 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7750 * Hitachi SH7000 and E7000-PC ICE support
7752 There is now support for communicating with the Hitachi E7000-PC ICE.
7753 This is available automatically when GDB is configured for the SH.
7757 As usual, a variety of small fixes and improvements, both generic
7758 and configuration-specific. See the ChangeLog for more detail.
7760 *** Changes in GDB-4.12:
7762 * Irix 5 is now supported
7766 GDB-4.12 on the HPPA has a number of changes which make it unable
7767 to debug the output from the currently released versions of GCC and
7768 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
7769 of GCC and GAS, versions of these tools designed to work with GDB-4.12
7770 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
7773 *** Changes in GDB-4.11:
7775 * User visible changes:
7779 The "set remotedebug" option is now consistent between the mips remote
7780 target, remote targets using the gdb-specific protocol, UDI (AMD's
7781 debug protocol for the 29k) and the 88k bug monitor. It is now an
7782 integer specifying a debug level (normally 0 or 1, but 2 means more
7783 debugging info for the mips target).
7785 * DEC Alpha native support
7787 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
7788 debug info, but GDB works fairly well with the DEC compiler and should
7789 work with a future GCC release. See the README file for a few
7790 Alpha-specific notes.
7792 * Preliminary thread implementation
7794 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
7796 * LynxOS native and target support for 386
7798 This release has been hosted on LynxOS 2.2, and also can be configured
7799 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
7802 * Improvements in C++ mangling/demangling.
7804 This release has much better g++ debugging, specifically in name
7805 mangling/demangling, virtual function calls, print virtual table,
7806 call methods, ...etc.
7808 *** Changes in GDB-4.10:
7810 * User visible changes:
7812 Remote debugging using the GDB-specific (`target remote') protocol now
7813 supports the `load' command. This is only useful if you have some
7814 other way of getting the stub to the target system, and you can put it
7815 somewhere in memory where it won't get clobbered by the download.
7817 Filename completion now works.
7819 When run under emacs mode, the "info line" command now causes the
7820 arrow to point to the line specified. Also, "info line" prints
7821 addresses in symbolic form (as well as hex).
7823 All vxworks based targets now support a user settable option, called
7824 vxworks-timeout. This option represents the number of seconds gdb
7825 should wait for responses to rpc's. You might want to use this if
7826 your vxworks target is, perhaps, a slow software simulator or happens
7827 to be on the far side of a thin network line.
7831 This release contains support for using a DEC alpha as a GDB host for
7832 cross debugging. Native alpha debugging is not supported yet.
7835 *** Changes in GDB-4.9:
7839 This is the first GDB release which is accompanied by a matching testsuite.
7840 The testsuite requires installation of dejagnu, which should be available
7841 via ftp from most sites that carry GNU software.
7845 'Cfront' style demangling has had its name changed to 'ARM' style, to
7846 emphasize that it was written from the specifications in the C++ Annotated
7847 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
7848 disclaimers, it still generated too much confusion with users attempting to
7849 use gdb with AT&T cfront.
7853 GDB now uses a standard remote interface to a simulator library.
7854 So far, the library contains simulators for the Zilog Z8001/2, the
7855 Hitachi H8/300, H8/500 and Super-H.
7857 * New targets supported
7859 H8/300 simulator h8300-hitachi-hms or h8300hms
7860 H8/500 simulator h8500-hitachi-hms or h8500hms
7861 SH simulator sh-hitachi-hms or sh
7862 Z8000 simulator z8k-zilog-none or z8ksim
7863 IDT MIPS board over serial line mips-idt-ecoff
7865 Cross-debugging to GO32 targets is supported. It requires a custom
7866 version of the i386-stub.c module which is integrated with the
7867 GO32 memory extender.
7869 * New remote protocols
7871 MIPS remote debugging protocol.
7873 * New source languages supported
7875 This version includes preliminary support for Chill, a Pascal like language
7876 used by telecommunications companies. Chill support is also being integrated
7877 into the GNU compiler, but we don't know when it will be publically available.
7880 *** Changes in GDB-4.8:
7882 * HP Precision Architecture supported
7884 GDB now supports HP PA-RISC machines running HPUX. A preliminary
7885 version of this support was available as a set of patches from the
7886 University of Utah. GDB does not support debugging of programs
7887 compiled with the HP compiler, because HP will not document their file
7888 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
7889 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
7891 Many problems in the preliminary version have been fixed.
7893 * Faster and better demangling
7895 We have improved template demangling and fixed numerous bugs in the GNU style
7896 demangler. It can now handle type modifiers such as `static' or `const'. Wide
7897 character types (wchar_t) are now supported. Demangling of each symbol is now
7898 only done once, and is cached when the symbol table for a file is read in.
7899 This results in a small increase in memory usage for C programs, a moderate
7900 increase in memory usage for C++ programs, and a fantastic speedup in
7903 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
7904 from the specifications in the Annotated Reference Manual, which AT&T's
7905 compiler does not actually implement.
7907 * G++ multiple inheritance compiler problem
7909 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
7910 inheritance lattices was reworked to properly discover ambiguities. We
7911 recently found an example which causes this new algorithm to fail in a
7912 very subtle way, producing bad debug information for those classes.
7913 The file 'gcc.patch' (in this directory) can be applied to gcc to
7914 circumvent the problem. A future GCC release will contain a complete
7917 The previous G++ debug info problem (mentioned below for the gdb-4.7
7918 release) is fixed in gcc version 2.3.2.
7920 * Improved configure script
7922 The `configure' script will now attempt to guess your system type if
7923 you don't supply a host system type. The old scheme of supplying a
7924 host system triplet is preferable over using this. All the magic is
7925 done in the new `config.guess' script. Examine it for details.
7927 We have also brought our configure script much more in line with the FSF's
7928 version. It now supports the --with-xxx options. In particular,
7929 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
7930 The resulting GDB will not be able to read arbitrary object file formats --
7931 only the format ``expected'' to be used on the configured target system.
7932 We hope to make this the default in a future release.
7934 * Documentation improvements
7936 There's new internal documentation on how to modify GDB, and how to
7937 produce clean changes to the code. We implore people to read it
7938 before submitting changes.
7940 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
7941 M4 macros. The new texinfo.tex is provided in this release. Pre-built
7942 `info' files are also provided. To build `info' files from scratch,
7943 you will need the latest `makeinfo' release, which will be available in
7944 a future texinfo-X.Y release.
7946 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
7947 We're not sure exactly which versions have this problem, but it has
7948 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
7949 or better. If that isn't possible, there is a patch in
7950 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
7951 around this problem.
7955 GDB now supports array constants that can be used in expressions typed in by
7956 the user. The syntax is `{element, element, ...}'. Ie: you can now type
7957 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
7960 The new directory `gdb/sparclite' contains a program that demonstrates
7961 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
7963 * New native hosts supported
7965 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
7966 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
7968 * New targets supported
7970 AMD 29k family via UDI a29k-amd-udi or udi29k
7972 * New file formats supported
7974 BFD now supports reading HP/PA-RISC executables (SOM file format?),
7975 HPUX core files, and SCO 3.2v2 core files.
7979 Attaching to processes now works again; thanks for the many bug reports.
7981 We have also stomped on a bunch of core dumps caused by
7982 printf_filtered("%s") problems.
7984 We eliminated a copyright problem on the rpc and ptrace header files
7985 for VxWorks, which was discovered at the last minute during the 4.7
7986 release. You should now be able to build a VxWorks GDB.
7988 You can now interrupt gdb while an attached process is running. This
7989 will cause the attached process to stop, and give control back to GDB.
7991 We fixed problems caused by using too many file descriptors
7992 for reading symbols from object files and libraries. This was
7993 especially a problem for programs that used many (~100) shared
7996 The `step' command now only enters a subroutine if there is line number
7997 information for the subroutine. Otherwise it acts like the `next'
7998 command. Previously, `step' would enter subroutines if there was
7999 any debugging information about the routine. This avoids problems
8000 when using `cc -g1' on MIPS machines.
8002 * Internal improvements
8004 GDB's internal interfaces have been improved to make it easier to support
8005 debugging of multiple languages in the future.
8007 GDB now uses a common structure for symbol information internally.
8008 Minimal symbols (derived from linkage symbols in object files), partial
8009 symbols (from a quick scan of debug information), and full symbols
8010 contain a common subset of information, making it easier to write
8011 shared code that handles any of them.
8013 * New command line options
8015 We now accept --silent as an alias for --quiet.
8019 The memory-mapped-malloc library is now licensed under the GNU Library
8020 General Public License.
8022 *** Changes in GDB-4.7:
8024 * Host/native/target split
8026 GDB has had some major internal surgery to untangle the support for
8027 hosts and remote targets. Now, when you configure GDB for a remote
8028 target, it will no longer load in all of the support for debugging
8029 local programs on the host. When fully completed and tested, this will
8030 ensure that arbitrary host/target combinations are possible.
8032 The primary conceptual shift is to separate the non-portable code in
8033 GDB into three categories. Host specific code is required any time GDB
8034 is compiled on that host, regardless of the target. Target specific
8035 code relates to the peculiarities of the target, but can be compiled on
8036 any host. Native specific code is everything else: it can only be
8037 built when the host and target are the same system. Child process
8038 handling and core file support are two common `native' examples.
8040 GDB's use of /proc for controlling Unix child processes is now cleaner.
8041 It has been split out into a single module under the `target_ops' vector,
8042 plus two native-dependent functions for each system that uses /proc.
8044 * New hosts supported
8046 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8047 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8048 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8050 * New targets supported
8052 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8053 68030 and CPU32 m68030-*-*, m68332-*-*
8055 * New native hosts supported
8057 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8058 (386bsd is not well tested yet)
8059 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8061 * New file formats supported
8063 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8064 supports reading of `a.out.adobe' object files, which are an a.out
8065 format extended with minimal information about multiple sections.
8069 `show copying' is the same as the old `info copying'.
8070 `show warranty' is the same as `info warrantee'.
8071 These were renamed for consistency. The old commands continue to work.
8073 `info handle' is a new alias for `info signals'.
8075 You can now define pre-command hooks, which attach arbitrary command
8076 scripts to any command. The commands in the hook will be executed
8077 prior to the user's command. You can also create a hook which will be
8078 executed whenever the program stops. See gdb.texinfo.
8082 We now deal with Cfront style name mangling, and can even extract type
8083 info from mangled symbols. GDB can automatically figure out which
8084 symbol mangling style your C++ compiler uses.
8086 Calling of methods and virtual functions has been improved as well.
8090 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8091 fixed. This was due to mishandling of the extra N_SO stabs output
8094 We also finally got Ultrix 4.2 running in house, and fixed core file
8095 support, with help from a dozen people on the net.
8097 John M. Farrell discovered that the reason that single-stepping was so
8098 slow on all of the Mips based platforms (primarily SGI and DEC) was
8099 that we were trying to demangle and lookup a symbol used for internal
8100 purposes on every instruction that was being stepped through. Changing
8101 the name of that symbol so that it couldn't be mistaken for a C++
8102 mangled symbol sped things up a great deal.
8104 Rich Pixley sped up symbol lookups in general by getting much smarter
8105 about when C++ symbol mangling is necessary. This should make symbol
8106 completion (TAB on the command line) much faster. It's not as fast as
8107 we'd like, but it's significantly faster than gdb-4.6.
8111 A new user controllable variable 'call_scratch_address' can
8112 specify the location of a scratch area to be used when GDB
8113 calls a function in the target. This is necessary because the
8114 usual method of putting the scratch area on the stack does not work
8115 in systems that have separate instruction and data spaces.
8117 We integrated changes to support the 29k UDI (Universal Debugger
8118 Interface), but discovered at the last minute that we didn't have all
8119 of the appropriate copyright paperwork. We are working with AMD to
8120 resolve this, and hope to have it available soon.
8124 We have sped up the remote serial line protocol, especially for targets
8125 with lots of registers. It now supports a new `expedited status' ('T')
8126 message which can be used in place of the existing 'S' status message.
8127 This allows the remote stub to send only the registers that GDB
8128 needs to make a quick decision about single-stepping or conditional
8129 breakpoints, eliminating the need to fetch the entire register set for
8130 each instruction being stepped through.
8132 The GDB remote serial protocol now implements a write-through cache for
8133 registers, only re-reading the registers if the target has run.
8135 There is also a new remote serial stub for SPARC processors. You can
8136 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8137 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8138 processor with a serial port.
8142 Configure.in files have become much easier to read and modify. A new
8143 `table driven' format makes it more obvious what configurations are
8144 supported, and what files each one uses.
8148 There is a new opcodes library which will eventually contain all of the
8149 disassembly routines and opcode tables. At present, it only contains
8150 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8151 disassembler (binutils/objdump) to share these routines.
8153 The libiberty library is now copylefted under the GNU Library General
8154 Public License. This allows more liberal use, and was done so libg++
8155 can use it. This makes no difference to GDB, since the Library License
8156 grants all the rights from the General Public License.
8160 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8161 reference to the stabs symbol info used by the debugger. It is (as far
8162 as we know) the only published document on this fascinating topic. We
8163 encourage you to read it, compare it to the stabs information on your
8164 system, and send improvements on the document in general (to
8165 bug-gdb@prep.ai.mit.edu).
8167 And, of course, many bugs have been fixed.
8170 *** Changes in GDB-4.6:
8172 * Better support for C++ function names
8174 GDB now accepts as input the "demangled form" of C++ overloaded function
8175 names and member function names, and can do command completion on such names
8176 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8177 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8178 Make use of command completion, it is your friend.
8180 GDB also now accepts a variety of C++ mangled symbol formats. They are
8181 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8182 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8183 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8184 for the list of formats.
8186 * G++ symbol mangling problem
8188 Recent versions of gcc have a bug in how they emit debugging information for
8189 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8190 directory) can be applied to gcc to fix the problem. Alternatively, if you
8191 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8192 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8193 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8196 * New 'maintenance' command
8198 All of the commands related to hacking GDB internals have been moved out of
8199 the main command set, and now live behind the 'maintenance' command. This
8200 can also be abbreviated as 'mt'. The following changes were made:
8202 dump-me -> maintenance dump-me
8203 info all-breakpoints -> maintenance info breakpoints
8204 printmsyms -> maintenance print msyms
8205 printobjfiles -> maintenance print objfiles
8206 printpsyms -> maintenance print psymbols
8207 printsyms -> maintenance print symbols
8209 The following commands are new:
8211 maintenance demangle Call internal GDB demangler routine to
8212 demangle a C++ link name and prints the result.
8213 maintenance print type Print a type chain for a given symbol
8215 * Change to .gdbinit file processing
8217 We now read the $HOME/.gdbinit file before processing the argv arguments
8218 (e.g. reading symbol files or core files). This allows global parameters to
8219 be set, which will apply during the symbol reading. The ./.gdbinit is still
8220 read after argv processing.
8222 * New hosts supported
8224 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8226 GNU/Linux support i386-unknown-linux or linux
8228 We are also including code to support the HP/PA running BSD and HPUX. This
8229 is almost guaranteed not to work, as we didn't have time to test or build it
8230 for this release. We are including it so that the more adventurous (or
8231 masochistic) of you can play with it. We also had major problems with the
8232 fact that the compiler that we got from HP doesn't support the -g option.
8235 * New targets supported
8237 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8239 * More smarts about finding #include files
8241 GDB now remembers the compilation directory for all include files, and for
8242 all files from which C is generated (like yacc and lex sources). This
8243 greatly improves GDB's ability to find yacc/lex sources, and include files,
8244 especially if you are debugging your program from a directory different from
8245 the one that contains your sources.
8247 We also fixed a bug which caused difficulty with listing and setting
8248 breakpoints in include files which contain C code. (In the past, you had to
8249 try twice in order to list an include file that you hadn't looked at before.)
8251 * Interesting infernals change
8253 GDB now deals with arbitrary numbers of sections, where the symbols for each
8254 section must be relocated relative to that section's landing place in the
8255 target's address space. This work was needed to support ELF with embedded
8256 stabs used by Solaris-2.0.
8258 * Bug fixes (of course!)
8260 There have been loads of fixes for the following things:
8261 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8262 i960, stabs, DOS(GO32), procfs, etc...
8264 See the ChangeLog for details.
8266 *** Changes in GDB-4.5:
8268 * New machines supported (host and target)
8270 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8272 SGI Irix-4.x mips-sgi-irix4 or iris4
8274 * New malloc package
8276 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8277 Mmalloc is capable of handling multiple heaps of memory. It is also
8278 capable of saving a heap to a file, and then mapping it back in later.
8279 This can be used to greatly speedup the startup of GDB by using a
8280 pre-parsed symbol table which lives in a mmalloc managed heap. For
8281 more details, please read mmalloc/mmalloc.texi.
8285 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8286 'help info proc' for details.
8288 * MIPS ecoff symbol table format
8290 The code that reads MIPS symbol table format is now supported on all hosts.
8291 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8294 * File name changes for MS-DOS
8296 Many files in the config directories have been renamed to make it easier to
8297 support GDB on MS-DOSe systems (which have very restrictive file name
8298 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8299 environment) is close to working but has some remaining problems. Note
8300 that debugging of DOS programs is not supported, due to limitations
8301 in the ``operating system'', but it can be used to host cross-debugging.
8303 * Cross byte order fixes
8305 Many fixes have been made to support cross debugging of Sparc and MIPS
8306 targets from hosts whose byte order differs.
8308 * New -mapped and -readnow options
8310 If memory-mapped files are available on your system through the 'mmap'
8311 system call, you can use the -mapped option on the `file' or
8312 `symbol-file' commands to cause GDB to write the symbols from your
8313 program into a reusable file. If the program you are debugging is
8314 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8315 Future GDB debugging sessions will notice the presence of this file,
8316 and will quickly map in symbol information from it, rather than reading
8317 the symbol table from the executable program. Using the '-mapped'
8318 option in a GDB `file' or `symbol-file' command has the same effect as
8319 starting GDB with the '-mapped' command-line option.
8321 You can cause GDB to read the entire symbol table immediately by using
8322 the '-readnow' option with any of the commands that load symbol table
8323 information (or on the GDB command line). This makes the command
8324 slower, but makes future operations faster.
8326 The -mapped and -readnow options are typically combined in order to
8327 build a `fred.syms' file that contains complete symbol information.
8328 A simple GDB invocation to do nothing but build a `.syms' file for future
8331 gdb -batch -nx -mapped -readnow programname
8333 The `.syms' file is specific to the host machine on which GDB is run.
8334 It holds an exact image of GDB's internal symbol table. It cannot be
8335 shared across multiple host platforms.
8337 * longjmp() handling
8339 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8340 siglongjmp() without losing control. This feature has not yet been ported to
8341 all systems. It currently works on many 386 platforms, all MIPS-based
8342 platforms (SGI, DECstation, etc), and Sun3/4.
8346 Preliminary work has been put in to support the new Solaris OS from Sun. At
8347 this time, it can control and debug processes, but it is not capable of
8352 As always, many many bug fixes. The major areas were with g++, and mipsread.
8353 People using the MIPS-based platforms should experience fewer mysterious
8354 crashes and trashed symbol tables.
8356 *** Changes in GDB-4.4:
8358 * New machines supported (host and target)
8360 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8362 BSD Reno on Vax vax-dec-bsd
8363 Ultrix on Vax vax-dec-ultrix
8365 * New machines supported (target)
8367 AMD 29000 embedded, using EBMON a29k-none-none
8371 GDB continues to improve its handling of C++. `References' work better.
8372 The demangler has also been improved, and now deals with symbols mangled as
8373 per the Annotated C++ Reference Guide.
8375 GDB also now handles `stabs' symbol information embedded in MIPS
8376 `ecoff' symbol tables. Since the ecoff format was not easily
8377 extensible to handle new languages such as C++, this appeared to be a
8378 good way to put C++ debugging info into MIPS binaries. This option
8379 will be supported in the GNU C compiler, version 2, when it is
8382 * New features for SVR4
8384 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8385 shared libraries. Debugging dynamically linked programs should present
8386 only minor differences from debugging statically linked programs.
8388 The `info proc' command will print out information about any process
8389 on an SVR4 system (including the one you are debugging). At the moment,
8390 it prints the address mappings of the process.
8392 If you bring up GDB on another SVR4 system, please send mail to
8393 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8395 * Better dynamic linking support in SunOS
8397 Reading symbols from shared libraries which contain debugging symbols
8398 now works properly. However, there remain issues such as automatic
8399 skipping of `transfer vector' code during function calls, which
8400 make it harder to debug code in a shared library, than to debug the
8401 same code linked statically.
8405 GDB is now using the latest `getopt' routines from the FSF. This
8406 version accepts the -- prefix for options with long names. GDB will
8407 continue to accept the old forms (-option and +option) as well.
8408 Various single letter abbreviations for options have been explicity
8409 added to the option table so that they won't get overshadowed in the
8410 future by other options that begin with the same letter.
8414 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8415 Many assorted bugs have been handled. Many more remain to be handled.
8416 See the various ChangeLog files (primarily in gdb and bfd) for details.
8419 *** Changes in GDB-4.3:
8421 * New machines supported (host and target)
8423 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8424 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8425 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8427 * Almost SCO Unix support
8429 We had hoped to support:
8430 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8431 (except for core file support), but we discovered very late in the release
8432 that it has problems with process groups that render gdb unusable. Sorry
8433 about that. I encourage people to fix it and post the fixes.
8435 * Preliminary ELF and DWARF support
8437 GDB can read ELF object files on System V Release 4, and can handle
8438 debugging records for C, in DWARF format, in ELF files. This support
8439 is preliminary. If you bring up GDB on another SVR4 system, please
8440 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8445 GDB now uses the latest `readline' library. One user-visible change
8446 is that two tabs will list possible command completions, which previously
8447 required typing M-? (meta-question mark, or ESC ?).
8451 The `stepi' bug that many of you noticed has been squashed.
8452 Many bugs in C++ have been handled. Many more remain to be handled.
8453 See the various ChangeLog files (primarily in gdb and bfd) for details.
8455 * State of the MIPS world (in case you wondered):
8457 GDB can understand the symbol tables emitted by the compilers
8458 supplied by most vendors of MIPS-based machines, including DEC. These
8459 symbol tables are in a format that essentially nobody else uses.
8461 Some versions of gcc come with an assembler post-processor called
8462 mips-tfile. This program is required if you want to do source-level
8463 debugging of gcc-compiled programs. I believe FSF does not ship
8464 mips-tfile with gcc version 1, but it will eventually come with gcc
8467 Debugging of g++ output remains a problem. g++ version 1.xx does not
8468 really support it at all. (If you're lucky, you should be able to get
8469 line numbers and stack traces to work, but no parameters or local
8470 variables.) With some work it should be possible to improve the
8473 When gcc version 2 is released, you will have somewhat better luck.
8474 However, even then you will get confusing results for inheritance and
8477 We will eventually provide full debugging of g++ output on
8478 DECstations. This will probably involve some kind of stabs-in-ecoff
8479 encapulation, but the details have not been worked out yet.
8482 *** Changes in GDB-4.2:
8484 * Improved configuration
8486 Only one copy of `configure' exists now, and it is not self-modifying.
8487 Porting BFD is simpler.
8491 The `step' and `next' commands now only stop at the first instruction
8492 of a source line. This prevents the multiple stops that used to occur
8493 in switch statements, for-loops, etc. `Step' continues to stop if a
8494 function that has debugging information is called within the line.
8498 Lots of small bugs fixed. More remain.
8500 * New host supported (not target)
8502 Intel 386 PC clone running Mach i386-none-mach
8505 *** Changes in GDB-4.1:
8507 * Multiple source language support
8509 GDB now has internal scaffolding to handle several source languages.
8510 It determines the type of each source file from its filename extension,
8511 and will switch expression parsing and number formatting to match the
8512 language of the function in the currently selected stack frame.
8513 You can also specifically set the language to be used, with
8514 `set language c' or `set language modula-2'.
8518 GDB now has preliminary support for the GNU Modula-2 compiler,
8519 currently under development at the State University of New York at
8520 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8521 continue through the fall of 1991 and into 1992.
8523 Other Modula-2 compilers are currently not supported, and attempting to
8524 debug programs compiled with them will likely result in an error as the
8525 symbol table is read. Feel free to work on it, though!
8527 There are hooks in GDB for strict type checking and range checking,
8528 in the `Modula-2 philosophy', but they do not currently work.
8532 GDB can now write to executable and core files (e.g. patch
8533 a variable's value). You must turn this switch on, specify
8534 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8535 by assigning a new value to a variable. Modifications take
8538 * Automatic SunOS shared library reading
8540 When you run your program, GDB automatically determines where its
8541 shared libraries (if any) have been loaded, and reads their symbols.
8542 The `share' command is no longer needed. This also works when
8543 examining core files.
8547 You can specify the number of lines that the `list' command shows.
8550 * New machines supported (host and target)
8552 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8553 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8554 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8556 * New hosts supported (not targets)
8558 IBM RT/PC: romp-ibm-aix or rtpc
8560 * New targets supported (not hosts)
8562 AMD 29000 embedded with COFF a29k-none-coff
8563 AMD 29000 embedded with a.out a29k-none-aout
8564 Ultracomputer remote kernel debug a29k-nyu-kern
8566 * New remote interfaces
8572 *** Changes in GDB-4.0:
8576 Wide output is wrapped at good places to make the output more readable.
8578 Gdb now supports cross-debugging from a host machine of one type to a
8579 target machine of another type. Communication with the target system
8580 is over serial lines. The ``target'' command handles connecting to the
8581 remote system; the ``load'' command will download a program into the
8582 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8583 also supports debugging of realtime processes running under VxWorks,
8584 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8585 stub on the target system.
8587 New CPUs supported include the AMD 29000 and Intel 960.
8589 GDB now reads object files and symbol tables via a ``binary file''
8590 library, which allows a single copy of GDB to debug programs of multiple
8591 object file types such as a.out and coff.
8593 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8594 refcard.dvi and refcard.ps are available to format it).
8597 * Control-Variable user interface simplified
8599 All variables that control the operation of the debugger can be set
8600 by the ``set'' command, and displayed by the ``show'' command.
8602 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8603 ``Show prompt'' produces the response:
8604 Gdb's prompt is new-gdb=>.
8606 What follows are the NEW set commands. The command ``help set'' will
8607 print a complete list of old and new set commands. ``help set FOO''
8608 will give a longer description of the variable FOO. ``show'' will show
8609 all of the variable descriptions and their current settings.
8611 confirm on/off: Enables warning questions for operations that are
8612 hard to recover from, e.g. rerunning the program while
8613 it is already running. Default is ON.
8615 editing on/off: Enables EMACS style command line editing
8616 of input. Previous lines can be recalled with
8617 control-P, the current line can be edited with control-B,
8618 you can search for commands with control-R, etc.
8621 history filename NAME: NAME is where the gdb command history
8622 will be stored. The default is .gdb_history,
8623 or the value of the environment variable
8626 history size N: The size, in commands, of the command history. The
8627 default is 256, or the value of the environment variable
8630 history save on/off: If this value is set to ON, the history file will
8631 be saved after exiting gdb. If set to OFF, the
8632 file will not be saved. The default is OFF.
8634 history expansion on/off: If this value is set to ON, then csh-like
8635 history expansion will be performed on
8636 command line input. The default is OFF.
8638 radix N: Sets the default radix for input and output. It can be set
8639 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8640 in the current radix, so "set radix 10" is always a no-op.
8642 height N: This integer value is the number of lines on a page. Default
8643 is 24, the current `stty rows'' setting, or the ``li#''
8644 setting from the termcap entry matching the environment
8647 width N: This integer value is the number of characters on a line.
8648 Default is 80, the current `stty cols'' setting, or the ``co#''
8649 setting from the termcap entry matching the environment
8652 Note: ``set screensize'' is obsolete. Use ``set height'' and
8653 ``set width'' instead.
8655 print address on/off: Print memory addresses in various command displays,
8656 such as stack traces and structure values. Gdb looks
8657 more ``symbolic'' if you turn this off; it looks more
8658 ``machine level'' with it on. Default is ON.
8660 print array on/off: Prettyprint arrays. New convenient format! Default
8663 print demangle on/off: Print C++ symbols in "source" form if on,
8666 print asm-demangle on/off: Same, for assembler level printouts
8669 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8672 * Support for Epoch Environment.
8674 The epoch environment is a version of Emacs v18 with windowing. One
8675 new command, ``inspect'', is identical to ``print'', except that if you
8676 are running in the epoch environment, the value is printed in its own
8680 * Support for Shared Libraries
8682 GDB can now debug programs and core files that use SunOS shared libraries.
8683 Symbols from a shared library cannot be referenced
8684 before the shared library has been linked with the program (this
8685 happens after you type ``run'' and before the function main() is entered).
8686 At any time after this linking (including when examining core files
8687 from dynamically linked programs), gdb reads the symbols from each
8688 shared library when you type the ``sharedlibrary'' command.
8689 It can be abbreviated ``share''.
8691 sharedlibrary REGEXP: Load shared object library symbols for files
8692 matching a unix regular expression. No argument
8693 indicates to load symbols for all shared libraries.
8695 info sharedlibrary: Status of loaded shared libraries.
8700 A watchpoint stops execution of a program whenever the value of an
8701 expression changes. Checking for this slows down execution
8702 tremendously whenever you are in the scope of the expression, but is
8703 quite useful for catching tough ``bit-spreader'' or pointer misuse
8704 problems. Some machines such as the 386 have hardware for doing this
8705 more quickly, and future versions of gdb will use this hardware.
8707 watch EXP: Set a watchpoint (breakpoint) for an expression.
8709 info watchpoints: Information about your watchpoints.
8711 delete N: Deletes watchpoint number N (same as breakpoints).
8712 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8713 enable N: Re-enables watchpoint number N (same as breakpoints).
8716 * C++ multiple inheritance
8718 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8721 * C++ exception handling
8723 Gdb now supports limited C++ exception handling. Besides the existing
8724 ability to breakpoint on an exception handler, gdb can breakpoint on
8725 the raising of an exception (before the stack is peeled back to the
8728 catch FOO: If there is a FOO exception handler in the dynamic scope,
8729 set a breakpoint to catch exceptions which may be raised there.
8730 Multiple exceptions (``catch foo bar baz'') may be caught.
8732 info catch: Lists all exceptions which may be caught in the
8733 current stack frame.
8736 * Minor command changes
8738 The command ``call func (arg, arg, ...)'' now acts like the print
8739 command, except it does not print or save a value if the function's result
8740 is void. This is similar to dbx usage.
8742 The ``up'' and ``down'' commands now always print the frame they end up
8743 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8744 frames without printing.
8746 * New directory command
8748 'dir' now adds directories to the FRONT of the source search path.
8749 The path starts off empty. Source files that contain debug information
8750 about the directory in which they were compiled can be found even
8751 with an empty path; Sun CC and GCC include this information. If GDB can't
8752 find your source file in the current directory, type "dir .".
8754 * Configuring GDB for compilation
8756 For normal use, type ``./configure host''. See README or gdb.texinfo
8759 GDB now handles cross debugging. If you are remotely debugging between
8760 two different machines, type ``./configure host -target=targ''.
8761 Host is the machine where GDB will run; targ is the machine
8762 where the program that you are debugging will run.