1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 14
6 * Building GDB and GDBserver now requires a C++17 compiler.
7 For example, GCC 9 or later.
9 * GDB index now contains information about the main function. This speeds up
10 startup when it is being used for some large binaries.
15 Attempting to use both the 'r' and 'b' flags with the disassemble
16 command will now give an error. Previously the 'b' flag would
17 always override the 'r' flag.
21 info missing-debug-handler
22 List all the registered missing debug handlers.
24 enable missing-debug-handler LOCUS HANDLER
25 disable missing-debug-handler LOCUS HANDLER
26 Enable or disable a missing debug handler with a name matching the
27 regular expression HANDLER, in LOCUS.
29 LOCUS can be 'global' to operate on global missing debug handler,
30 'progspace' to operate on handlers within the current program space,
31 or can be a regular expression which is matched against the filename
32 of the primary executable in each program space.
34 maintenance info linux-lwps
35 List all LWPs under control of the linux-nat target.
37 set remote thread-options-packet
38 show remote thread-options-packet
39 Set/show the use of the thread options packet.
43 ** New function gdb.notify_mi(NAME, DATA), that emits custom
44 GDB/MI async notification.
46 ** New read/write attribute gdb.Value.bytes that contains a bytes
47 object holding the contents of this value.
49 ** New module gdb.missing_debug that facilitates dealing with
50 objfiles that are missing any debug information.
52 ** New function gdb.missing_debug.register_handler that can register
53 an instance of a sub-class of gdb.missing_debug.MissingDebugInfo
54 as a handler for objfiles that are missing debug information.
56 ** New class gdb.missing_debug.MissingDebugInfo which can be
57 sub-classed to create handlers for objfiles with missing debug
62 New stop reason: clone
63 Indicates that a clone system call was executed.
66 Enable/disable optional event reporting, on a per-thread basis.
67 Currently supported options are GDB_THREAD_OPTION_CLONE, to enable
68 clone event reporting, and GDB_THREAD_OPTION_EXIT to enable thread
71 QThreadOptions in qSupported
72 The qSupported packet allows GDB to inform the stub it supports the
73 QThreadOptions packet, and the qSupported response can contain the
74 set of thread options the remote stub supports.
78 * GDB now supports the AArch64 Scalable Matrix Extension 2 (SME2), which
79 includes a new 512 bit lookup table register named ZT0.
81 * GDB now supports the AArch64 Scalable Matrix Extension (SME), which includes
82 a new matrix register named ZA, a new thread register TPIDR2 and a new vector
83 length register SVG (streaming vector granule). GDB also supports tracking
84 ZA state across signal frames.
86 Some features are still under development or are dependent on ABI specs that
87 are still in alpha stage. For example, manual function calls with ZA state
88 don't have any special handling, and tracking of SVG changes based on
89 DWARF information is still not implemented, but there are plans to do so in
92 * GDB now recognizes the NO_COLOR environment variable and disables
93 styling according to the spec. See https://no-color.org/.
94 Styling can be re-enabled with "set style enabled on".
96 * The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
97 has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
100 * GDB now has some support for integer types larger than 64 bits.
102 * Removed targets and native configurations
104 GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
105 AIX version is now AIX 7.1.
107 * Multi-target feature configuration
109 GDB now supports the individual configuration of remote targets' feature
110 sets. Based on the current selection of a target, the commands 'set remote
111 <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
112 configure a target's feature packet and to display its configuration,
115 The individual packet sizes can be configured and shown using the commands
116 ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
117 ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
118 ** 'show remote memory-read-packet-size'
119 ** 'show remote memory-write-packet-size'.
121 The configuration of the packet itself, as well as the size of a memory-read
122 or memory-write packet applies to the currently selected target (if
123 available). If no target is selected, it applies to future remote
124 connections. Similarly, the show commands print the configuration of the
125 currently selected target. If no remote target is selected, the default
126 configuration for future connections is shown.
128 * GDB has initial built-in support for the Debugger Adapter Protocol.
129 This support requires that GDB be built with Python scripting
132 * For the break command, multiple uses of the 'thread' or 'task'
133 keywords will now give an error instead of just using the thread or
134 task id from the last instance of the keyword. E.g.:
135 break foo thread 1 thread 2
136 will now give an error rather than using 'thread 2'.
138 * For the watch command, multiple uses of the 'task' keyword will now
139 give an error instead of just using the task id from the last
140 instance of the keyword. E.g.:
141 watch my_var task 1 task 2
142 will now give an error rather than using 'task 2'. The 'thread'
143 keyword already gave an error when used multiple times with the
144 watch command, this remains unchanged.
146 * The 'set print elements' setting now helps when printing large arrays.
147 If an array would otherwise exceed max-value-size, but 'print elements'
148 is set such that the size of elements to print is less than or equal
149 to 'max-value-size', GDB will now still print the array, however only
150 'max-value-size' worth of data will be added into the value history.
152 * For both the break and watch commands, it is now invalid to use both
153 the 'thread' and 'task' keywords within the same command. For
154 example the following commnds will now give an error:
155 break foo thread 1 task 1
156 watch var thread 2 task 3
158 * The printf command now accepts a '%V' output format which will
159 format an expression just as the 'print' command would. Print
160 options can be placed withing '[...]' after the '%V' to modify how
161 the value is printed. E.g:
162 printf "%V", some_array
163 printf "%V[-array-indexes on]", some_array
164 will print the array without, or with array indexes included, just
165 as the array would be printed by the 'print' command. This
166 functionality is also available for dprintf when dprintf-style is
169 * When the printf command requires a string to be fetched from the
170 inferior, GDB now uses the existing 'max-value-size' setting to the
171 limit the memory allocated within GDB. The default 'max-value-size'
172 is 64k. To print longer strings you should increase
175 * The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
177 * The Ada 2022 target name symbol ('@') is now supported by the Ada
180 * The 'list' command now accepts '.' as an argument, which tells GDB to
181 print the location around the point of execution within the current frame.
182 If the inferior hasn't started yet, the command will print around the
183 beginning of the 'main' function.
185 * Using the 'list' command with no arguments in a situation where the
186 command would attempt to list past the end of the file now warns the
187 user that the end of file has been reached, refers the user to the
188 newly added '.' argument
190 * Breakpoints can now be inferior-specific. This is similar to the
191 existing thread-specific breakpoint support. Breakpoint conditions
192 can include the 'inferior' keyword followed by an inferior id (as
193 displayed in the 'info inferiors' output). It is invalid to use the
194 'inferior' keyword with either the 'thread' or 'task' keywords when
195 creating a breakpoint.
197 * New convenience function "$_shell", to execute a shell command and
198 return the result. This lets you run shell commands in expressions.
201 (gdb) p $_shell("true")
203 (gdb) p $_shell("false")
205 (gdb) break func if $_shell("some command") == 0
209 --additional-debug-dirs=PATHs
211 Provide a colon-separated list of additional directories to search for
212 separate debug info. These directories are added to the default value of
213 the 'debug-file-directory' GDB parameter.
217 set debug breakpoint on|off
218 show debug breakpoint
219 Print additional debug messages about breakpoint insertion and removal.
221 maintenance print record-instruction [ N ]
222 Print the recorded information for a given instruction. If N is not given
223 prints how GDB would undo the last instruction executed. If N is negative,
224 prints how GDB would undo the N-th previous instruction, and if N is
225 positive, it prints how GDB will redo the N-th following instruction.
227 maintenance info frame-unwinders
228 List the frame unwinders currently in effect, starting with the highest
231 maintenance wait-for-index-cache
232 Wait until all pending writes to the index cache have completed.
234 set always-read-ctf on|off
236 When off, CTF is only read if DWARF is not present. When on, CTF is
237 read regardless of whether DWARF is present. Off by default.
240 Get main symbol to identify entry point into program.
242 set tui mouse-events [on|off]
243 show tui mouse-events
244 When on (default), mouse clicks control the TUI and can be accessed by
245 Python extensions. When off, mouse clicks are handled by the terminal,
246 enabling terminal-native text selection.
250 ** MI version 1 has been removed.
252 ** mi now reports 'no-history' as a stop reason when hitting the end of the
253 reverse execution history.
255 ** When creating a thread-specific breakpoint using the '-p' option,
256 the -break-insert command would report the 'thread' field twice in
257 the reply. The content of both fields was always identical. This
258 has now been fixed; the 'thread' field will be reported just once
259 for thread-specific breakpoints, or not at all for breakpoints
260 without a thread restriction. The same is also true for the 'task'
261 field of an Ada task-specific breakpoint.
263 ** It is no longer possible to create a thread-specific breakpoint for
264 a thread that doesn't exist using '-break-insert -p ID'. Creating
265 breakpoints for non-existent threads is not allowed when using the
266 CLI, that the MI allowed it was a long standing bug, which has now
269 ** The '--simple-values' argument to the '-stack-list-arguments',
270 '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
271 commands now takes reference types into account: that is, a value is now
272 considered simple if it is neither an array, structure, or union, nor a
273 reference to an array, structure, or union. (Previously all references were
274 considered simple.) Support for this feature can be verified by using the
275 '-list-features' command, which should contain "simple-values-ref-types".
277 ** The -break-insert command now accepts a '-g thread-group-id' option
278 to allow for the creation of inferior-specific breakpoints.
280 ** The bkpt tuple, which appears in breakpoint-created notifications,
281 and in the result of the -break-insert command can now include an
282 optional 'inferior' field for both the main breakpoint, and each
283 location, when the breakpoint is inferior-specific.
287 ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
289 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
291 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
292 now be of type 'str' otherwise a TypeError will be raised.
294 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
295 values of type 'bool'. Changing this attribute will now
296 invalidate GDB's frame-cache, which means GDB will need to
297 rebuild its frame-cache when next required - either with, or
298 without the particular unwinder, depending on how 'enabled' was
301 ** New methods added to the gdb.PendingFrame class. These methods
302 have the same behaviour as the corresponding methods on
303 gdb.Frame. The new methods are:
305 - gdb.PendingFrame.name: Return the name for the frame's
307 - gdb.PendingFrame.is_valid: Return True if the pending frame
309 - gdb.PendingFrame.pc: Return the $pc register value for this
311 - gdb.PendingFrame.language: Return a string containing the
312 language for this frame, or None.
313 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
314 object for the current location within the pending frame, or
316 - gdb.PendingFrame.block: Return a gdb.Block for the current
317 pending frame, or None.
318 - gdb.PendingFrame.function: Return a gdb.Symbol for the
319 current pending frame, or None.
321 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
322 now use either an integer or a gdb.Value object for each of its
323 'sp', 'pc', and 'special' attributes.
325 ** A new class gdb.unwinder.FrameId has been added. Instances of
326 this class are constructed with 'sp' (stack-pointer) and 'pc'
327 (program-counter) values, and can be used as the frame-id when
328 calling gdb.PendingFrame.create_unwind_info.
330 ** It is now no longer possible to sub-class the
331 gdb.disassembler.DisassemblerResult type.
333 ** The Disassembler API from the gdb.disassembler module has been
334 extended to include styling support:
336 - The DisassemblerResult class can now be initialized with a list
337 of parts. Each part represents part of the disassembled
338 instruction along with the associated style information. This
339 list of parts can be accessed with the new
340 DisassemblerResult.parts property.
342 - New constants gdb.disassembler.STYLE_* representing all the
343 different styles part of an instruction might have.
345 - New methods DisassembleInfo.text_part and
346 DisassembleInfo.address_part which are used to create the new
347 styled parts of a disassembled instruction.
349 - Changes are backwards compatible, the older API can still be
350 used to disassemble instructions without styling.
352 ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
353 GDB/MI command and returns the output as a Python dictionary.
355 ** New function gdb.block_signals(). This returns a context manager
356 that blocks any signals that GDB needs to handle itself.
358 ** New class gdb.Thread. This is a subclass of threading.Thread
359 that calls gdb.block_signals in its "start" method.
361 ** gdb.parse_and_eval now has a new "global_context" parameter.
362 This can be used to request that the parse only examine global
365 ** gdb.Inferior now has a new "arguments" attribute. This holds the
366 command-line arguments to the inferior, if known.
368 ** gdb.Inferior now has a new "main_name" attribute. This holds the
369 name of the inferior's "main", if known.
371 ** gdb.Inferior now has new methods "clear_env", "set_env", and
372 "unset_env". These can be used to modify the inferior's
373 environment before it is started.
375 ** gdb.Value now has the 'assign' method.
377 ** gdb.Value now has the 'to_array' method. This converts an
378 array-like Value to an array.
380 ** gdb.Progspace now has the new method "objfile_for_address". This
381 returns the gdb.Objfile, if any, that covers a given address.
383 ** gdb.Breakpoint now has an "inferior" attribute. If the
384 Breakpoint object is inferior specific then this attribute holds
385 the inferior-id (an integer). If the Breakpoint object is not
386 inferior specific, then this field contains None. This field can
389 ** gdb.Type now has the "is_array_like" and "is_string_like"
390 methods. These reflect GDB's internal idea of whether a type
391 might be array- or string-like, even if they do not have the
392 corresponding type code.
394 ** gdb.ValuePrinter is a new class that can be used as the base
395 class for the result of applying a pretty-printer. As a base
396 class, it signals to gdb that the printer may implement new
397 pretty-printer methods.
399 ** New attribute Progspace.symbol_file. This attribute holds the
400 gdb.Objfile that corresponds to Progspace.filename (when
401 Progspace.filename is not None), otherwise, this attribute is
404 ** New attribute Progspace.executable_filename. This attribute
405 holds a string containing a file name set by the "exec-file" or
406 "file" commands, or None if no executable file is set. This
407 isn't the exact string passed by the user to these commands; the
408 file name will have been partially resolved to an absolute file
411 ** A new executable_changed event registry is available. This event
412 emits ExecutableChangedEvent objects, which have 'progspace' (a
413 gdb.Progspace) and 'reload' (a Boolean) attributes. This event
414 is emitted when gdb.Progspace.executable_filename changes.
416 ** New event registries gdb.events.new_progspace and
417 gdb.events.free_progspace, these emit NewProgspaceEvent and
418 FreeProgspaceEvent event types respectively. Both of these event
419 types have a single 'progspace' attribute, which is the
420 gdb.Progspace that is either being added to GDB, or removed from
423 ** gdb.LazyString now implements the __str__ method.
425 ** New method gdb.Frame.static_link that returns the outer frame
426 of a nested function frame.
428 *** Changes in GDB 13
430 * MI version 1 is deprecated, and will be removed in GDB 14.
432 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
433 reading memory tag data for AArch64 MTE from core files generated by
434 the gcore command or the Linux kernel.
436 When a process uses memory-mapped pages protected by memory tags (for
437 example, AArch64 MTE), this additional information will be recorded in
438 the core file in the event of a crash or if GDB generates a core file
439 from the current process state. GDB will show this additional information
440 automatically, or through one of the memory-tag subcommands.
442 * Scheduler-locking and new threads
444 When scheduler-locking is in effect, only the current thread may run
445 when the inferior is resumed. However, previously, new threads
446 created by the resumed thread would still be able to run free. Now,
447 they are held stopped.
449 * "info breakpoints" now displays enabled breakpoint locations of
450 disabled breakpoints as in the "y-" state. For example:
452 (gdb) info breakpoints
453 Num Type Disp Enb Address What
454 1 breakpoint keep n <MULTIPLE>
455 1.1 y- 0x00000000000011b6 in ...
456 1.2 y- 0x00000000000011c2 in ...
457 1.3 n 0x00000000000011ce in ...
459 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
460 aarch64 architectures.
462 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
464 * Remove support for building against Python 2, it is now only possible to
465 build GDB against Python 3.
467 * DBX mode has been removed.
469 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
470 emit to indicate where a breakpoint should be placed to break in a function
473 * Completion now also offers "NUMBER" for "set" commands that accept
474 a numeric argument and the "unlimited" keyword. For example:
476 (gdb) set width <TAB>
481 (gdb) complete set width
485 * Disassembler styling using libopcodes. GDB now supports
486 disassembler styling using libopcodes. This is only available for
487 some targets (currently x86 and RISC-V). For unsupported targets
488 Python Pygments is still used. For supported targets, libopcodes
489 styling is used by default.
491 * The Windows native target now supports target async.
493 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
495 * The format of 'disassemble /r' and 'record instruction-history /r'
496 has changed. The instruction bytes could now be grouped together,
497 and displayed in the endianness of the instruction. This is the
498 same layout as used by GNU objdump when disassembling.
500 There is now 'disassemble /b' and 'record instruction-history /b'
501 which will always display the instructions bytes one at a time in
502 memory order, that is, the byte at the lowest address first.
504 For both /r and /b GDB is now better at using whitespace in order to
505 align the disassembled instruction text.
507 * The TUI no longer styles the source and assembly code highlighted by
508 the current position indicator by default. You can however
509 re-enable styling using the new "set style tui-current-position"
512 * New convenience variable $_inferior_thread_count contains the number
513 of live threads in the current inferior.
515 * When a breakpoint with multiple code locations is hit, GDB now prints
516 the code location using the syntax <breakpoint_number>.<location_number>
518 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
520 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
521 and $_hit_locno to the hit breakpoint number and code location number.
522 This allows to disable the last hit breakpoint using
523 (gdb) disable $_hit_bpnum
524 or disable only the specific breakpoint code location using
525 (gdb) disable $_hit_bpnum.$_hit_locno
526 These commands can be used inside the command list of a breakpoint to
527 automatically disable the just encountered breakpoint (or the just
528 encountered specific breakpoint code location).
529 When a breakpoint has only one location, $_hit_locno is set to 1 so that
530 (gdb) disable $_hit_bpnum.$_hit_locno
532 (gdb) disable $_hit_bpnum
533 are both disabling the breakpoint.
537 maintenance set ignore-prologue-end-flag on|off
538 maintenance show ignore-prologue-end-flag
539 This setting, which is off by default, controls whether GDB ignores the
540 PROLOGUE-END flag from the line-table when skipping prologue. This can be
541 used to force GDB to use prologue analyzers if the line-table is constructed
542 from erroneous debug information.
544 set print nibbles [on|off]
546 This controls whether the 'print/t' command will display binary values
547 in groups of four bits, known as "nibbles". The default is 'off'.
549 maintenance set libopcodes-styling on|off
550 maintenance show libopcodes-styling
551 These can be used to force off libopcodes based styling, the Python
552 Pygments styling will then be used instead.
554 set style disassembler comment
555 show style disassembler comment
556 set style disassembler immediate
557 show style disassembler immediate
558 set style disassembler mnemonic
559 show style disassembler mnemonic
560 set style disassembler register
561 show style disassembler register
562 set style disassembler address
563 show style disassembler address
564 set style disassembler symbol
565 show style disassembler symbol
566 For targets that support libopcodes based styling, these settings
567 control how various aspects of the disassembler output are styled.
568 The 'disassembler address' and 'disassembler symbol' styles are
569 aliases for the 'address' and 'function' styles respectively.
571 maintenance print frame-id [ LEVEL ]
572 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
573 not given, then print the frame-id for the currently selected frame.
575 set debug infcall on|off
577 Print additional debug messages about inferior function calls.
579 set debug solib on|off
581 Print additional debug messages about shared library handling.
583 set style tui-current-position [on|off]
584 Whether to style the source and assembly code highlighted by the
585 TUI's current position indicator. The default is off.
587 set print characters LIMIT
588 show print characters
589 This new setting is like 'set print elements', but controls how many
590 characters of a string are printed. This functionality used to be
591 covered by 'set print elements', but it can be controlled separately
592 now. LIMIT can be set to a numerical value to request that particular
593 character count, to 'unlimited' to print all characters of a string,
594 or to 'elements', which is also the default, to follow the setting of
595 'set print elements' as it used to be.
597 print -characters LIMIT
598 This new option to the 'print' command has the same effect as a temporary
599 use of 'set print characters'.
603 document user-defined
604 It is now possible to document user-defined aliases.
605 When a user-defined alias is documented, the help and apropos commands
606 use the provided documentation instead of the documentation of the
608 Documenting a user-defined alias is particularly useful when the alias
609 is a set of nested 'with' commands to avoid showing the help of
610 the with command for an alias that will in fact launch the
611 last command given in the nested commands.
613 maintenance info line-table
614 Add a PROLOGUE-END column to the output which indicates that an
615 entry corresponds to an address where a breakpoint should be placed
616 to be at the first instruction past a function's prologue.
620 set debug aix-solib on|off
622 set debug solib-frv on|off
624 Removed in favor of "set/show debug solib".
626 maintenance info program-spaces
627 This command now includes a 'Core File' column which indicates the
628 name of the core file associated with each program space.
632 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
634 GNU/Linux/CSKY (gdbserver) csky*-*linux*
640 ** The async record stating the stopped reason 'breakpoint-hit' now
641 contains an optional field locno giving the code location number
642 when the breakpoint has multiple code locations.
646 ** GDB will now reformat the doc string for gdb.Command and
647 gdb.Parameter sub-classes to remove unnecessary leading
648 whitespace from each line before using the string as the help
651 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
652 that formats ADDRESS as 'address <symbol+offset>', where symbol is
653 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
654 This is the same format that GDB uses when printing address, symbol,
655 and offset information from the disassembler.
657 ** New function gdb.current_language that returns the name of the
658 current language. Unlike gdb.parameter('language'), this will
661 ** New method gdb.Frame.language that returns the name of the
664 ** New Python API for wrapping GDB's disassembler:
666 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
667 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
668 ARCH is either None or a string containing a bfd architecture
669 name. DISASSEMBLER is registered as a disassembler for
670 architecture ARCH, or for all architectures if ARCH is None.
671 The previous disassembler registered for ARCH is returned, this
672 can be None if no previous disassembler was registered.
674 - gdb.disassembler.Disassembler is the class from which all
675 disassemblers should inherit. Its constructor takes a string,
676 a name for the disassembler, which is currently only used in
677 some debug output. Sub-classes should override the __call__
678 method to perform disassembly, invoking __call__ on this base
679 class will raise an exception.
681 - gdb.disassembler.DisassembleInfo is the class used to describe
682 a single disassembly request from GDB. An instance of this
683 class is passed to the __call__ method of
684 gdb.disassembler.Disassembler and has the following read-only
685 attributes: 'address', and 'architecture', as well as the
686 following method: 'read_memory'.
688 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
689 calls GDB's builtin disassembler on INFO, which is a
690 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
691 optional, its default value is None. If MEMORY_SOURCE is not
692 None then it must be an object that has a 'read_memory' method.
694 - gdb.disassembler.DisassemblerResult is a class that can be used
695 to wrap the result of a call to a Disassembler. It has
696 read-only attributes 'length' and 'string'.
698 ** gdb.Objfile now has an attribute named "is_file". This is True
699 if the objfile comes from a file, and False otherwise.
701 ** New function gdb.print_options that returns a dictionary of the
702 prevailing print options, in the form accepted by
703 gdb.Value.format_string.
705 ** gdb.Value.format_string now uses the format provided by 'print',
706 if it is called during a 'print' or other similar operation.
708 ** gdb.Value.format_string now accepts the 'summary' keyword. This
709 can be used to request a shorter representation of a value, the
710 way that 'set print frame-arguments scalars' does.
712 ** New Python type gdb.BreakpointLocation.
713 The new attribute 'locations' of gdb.Breakpoint returns a list of
714 gdb.BreakpointLocation objects specifying the locations where the
715 breakpoint is inserted into the debuggee.
717 ** The gdb.register_window_type method now restricts the set of
718 acceptable window names. The first character of a window's name
719 must start with a character in the set [a-zA-Z], every subsequent
720 character of a window's name must be in the set [-_.a-zA-Z0-9].
722 * New features in the GDB remote stub, GDBserver
724 ** GDBserver is now supported on LoongArch GNU/Linux.
726 ** GDBserver is now supported on CSKY GNU/Linux.
728 * LoongArch floating-point support
730 GDB now supports floating-point on LoongArch GNU/Linux.
732 * AMD GPU ROCm debugging support
734 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
737 *** Changes in GDB 12
739 * DBX mode is deprecated, and will be removed in GDB 13
741 * GDB 12 is the last release of GDB that will support building against
742 Python 2. From GDB 13, it will only be possible to build GDB itself
743 with Python 3 support.
745 * The disable-randomization setting now works on Windows.
747 * Improved C++ template support
749 GDB now treats functions/types involving C++ templates like it does function
750 overloads. Users may omit parameter lists to set breakpoints on families of
751 template functions, including types/functions composed of multiple template types:
753 (gdb) break template_func(template_1, int)
755 The above will set breakpoints at every function `template_func' where
756 the first function parameter is any template type named `template_1' and
757 the second function parameter is `int'.
759 TAB completion also gains similar improvements.
761 * The FreeBSD native target now supports async mode.
767 Enable or disable multithreaded symbol loading. This is enabled
768 by default, but passing --disable-threading or --enable-threading=no
769 to configure will disable it.
771 Disabling this can cause a performance penalty when there are a lot of
772 symbols to load, but is useful for debugging purposes.
776 maint set backtrace-on-fatal-signal on|off
777 maint show backtrace-on-fatal-signal
778 This setting is 'on' by default. When 'on' GDB will print a limited
779 backtrace to stderr in the situation where GDB terminates with a
780 fatal signal. This only supported on some platforms where the
781 backtrace and backtrace_symbols_fd functions are available.
783 set source open on|off
785 This setting, which is on by default, controls whether GDB will try
786 to open source code files. Switching this off will stop GDB trying
787 to open and read source code files, which can be useful if the files
788 are located over a slow network connection.
792 These are now deprecated aliases for "set max-value-size" and
793 "show max-value-size".
795 task apply [all | TASK-IDS...] [FLAG]... COMMAND
796 Like "thread apply", but applies COMMAND to Ada tasks.
799 Watchpoints can now be restricted to a specific Ada task.
801 maint set internal-error backtrace on|off
802 maint show internal-error backtrace
803 maint set internal-warning backtrace on|off
804 maint show internal-warning backtrace
805 GDB can now print a backtrace of itself when it encounters either an
806 internal-error, or an internal-warning. This is on by default for
807 internal-error and off by default for internal-warning.
810 Deprecated and replaced by "set logging enabled on|off".
812 set logging enabled on|off
814 These commands set or show whether logging is enabled or disabled.
817 You can now exit GDB by using the new command "exit", in addition to
818 the existing "quit" command.
820 set debug threads on|off
822 Print additional debug messages about thread creation and deletion.
824 set debug linux-nat on|off
826 These new commands replaced the old 'set debug lin-lwp' and 'show
827 debug lin-lwp' respectively. Turning this setting on prints debug
828 messages relating to GDB's handling of native Linux inferiors.
830 maint flush source-cache
831 Flush the contents of the source code cache.
833 maint set gnu-source-highlight enabled on|off
834 maint show gnu-source-highlight enabled
835 Whether GDB should use the GNU Source Highlight library for adding
836 styling to source code. When off, the library will not be used, even
837 when available. When GNU Source Highlight isn't used, or can't add
838 styling to a particular source file, then the Python Pygments
839 library will be used instead.
841 set suppress-cli-notifications (on|off)
842 show suppress-cli-notifications
843 This controls whether printing the notifications is suppressed for CLI.
844 CLI notifications occur when you change the selected context
845 (i.e., the current inferior, thread and/or the frame), or when
846 the program being debugged stops (e.g., because of hitting a
847 breakpoint, completing source-stepping, an interrupt, etc.).
849 set style disassembler enabled on|off
850 show style disassembler enabled
851 If GDB is compiled with Python support, and the Python Pygments
852 package is available, then, when this setting is on, disassembler
853 output will have styling applied.
855 set ada source-charset
856 show ada source-charset
857 Set the character set encoding that is assumed for Ada symbols. Valid
858 values for this follow the values that can be passed to the GNAT
859 compiler via the '-gnati' option. The default is ISO-8859-1.
865 These are the new names for the old 'layout', 'focus', 'refresh',
866 and 'winheight' tui commands respectively. The old names still
867 exist as aliases to these new commands.
871 The new command 'tui window width', and the alias 'winwidth' allow
872 the width of a tui window to be adjusted when windows are laid out
877 Control the display of debug output about GDB's tui.
882 Printing of floating-point values with base-modifying formats like
883 /x has been changed to display the underlying bytes of the value in
884 the desired base. This was GDB's documented behavior, but was never
885 implemented correctly.
888 This command can now print a reply, if the reply includes
889 non-printable characters. Any non-printable characters are printed
890 as escaped hex, e.g. \x?? where '??' is replaces with the value of
891 the non-printable character.
894 The clone-inferior command now ensures that the TTY, CMD and ARGS
895 settings are copied from the original inferior to the new one.
896 All modifications to the environment variables done using the 'set
897 environment' or 'unset environment' commands are also copied to the new
900 set debug lin-lwp on|off
902 These commands have been removed from GDB. The new command 'set
903 debug linux-nat' and 'show debug linux-nat' should be used
907 This command now includes information about the width of the tui
908 windows in its output.
914 These commands are now aliases for the 'tui layout', 'tui focus',
915 'tui refresh', and 'tui window height' commands respectively.
917 * GDB's Ada parser now supports an extension for specifying the exact
918 byte contents of a floating-point literal. This can be useful for
919 setting floating-point registers to a precise value without loss of
920 precision. The syntax is an extension of the based literal syntax.
921 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
922 of the floating-point type, and the "f" is the marker for floating
927 ** The '-add-inferior' with no option flags now inherits the
928 connection of the current inferior, this restores the behaviour of
929 GDB as it was prior to GDB 10.
931 ** The '-add-inferior' command now accepts a '--no-connection'
932 option, which causes the new inferior to start without a
935 ** The default version of the MI interpreter is now 4 (-i=mi4).
937 ** The "script" field in breakpoint output (which is syntactically
938 incorrect in MI 3 and below) has changed in MI 4 to become a list.
939 This affects the following commands and events:
943 - =breakpoint-created
944 - =breakpoint-modified
946 The -fix-breakpoint-script-output command can be used to enable
947 this behavior with previous MI versions.
951 GNU/Linux/LoongArch loongarch*-*-linux*
959 ** New function gdb.add_history(), which takes a gdb.Value object
960 and adds the value it represents to GDB's history list. An
961 integer, the index of the new item in the history list, is
964 ** New function gdb.history_count(), which returns the number of
965 values in GDB's value history.
967 ** New gdb.events.gdb_exiting event. This event is called with a
968 gdb.GdbExitingEvent object which has the read-only attribute
969 'exit_code', which contains the value of the GDB exit code. This
970 event is triggered once GDB decides it is going to exit, but
971 before GDB starts to clean up its internal state.
973 ** New function gdb.architecture_names(), which returns a list
974 containing all of the possible Architecture.name() values. Each
977 ** New function gdb.Architecture.integer_type(), which returns an
978 integer type given a size and a signed-ness.
980 ** New gdb.TargetConnection object type that represents a connection
981 (as displayed by the 'info connections' command). A sub-class,
982 gdb.RemoteTargetConnection, is used to represent 'remote' and
983 'extended-remote' connections.
985 ** The gdb.Inferior type now has a 'connection' property which is an
986 instance of gdb.TargetConnection, the connection used by this
987 inferior. This can be None if the inferior has no connection.
989 ** New 'gdb.events.connection_removed' event registry, which emits a
990 'gdb.ConnectionEvent' when a connection is removed from GDB.
991 This event has a 'connection' property, a gdb.TargetConnection
992 object for the connection being removed.
994 ** New gdb.connections() function that returns a list of all
995 currently active connections.
997 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
998 is equivalent to the existing 'maint packet' CLI command; it
999 allows a user specified packet to be sent to the remote target.
1001 ** New function gdb.host_charset(), returns a string, which is the
1002 name of the current host charset.
1004 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
1007 ** New gdb.with_parameter(NAME, VALUE). This returns a context
1008 manager that temporarily sets the gdb parameter NAME to VALUE,
1009 then resets it when the context is exited.
1011 ** The gdb.Value.format_string method now takes a 'styling'
1012 argument, which is a boolean. When true, the returned string can
1013 include escape sequences to apply styling. The styling will only
1014 be present if styling is otherwise turned on in GDB (see 'help
1015 set styling'). When false, which is the default if the argument
1016 is not given, then no styling is applied to the returned string.
1018 ** New read-only attribute gdb.InferiorThread.details, which is
1019 either a string, containing additional, target specific thread
1020 state information, or None, if there is no such additional
1023 ** New read-only attribute gdb.Type.is_scalar, which is True for
1024 scalar types, and False for all other types.
1026 ** New read-only attribute gdb.Type.is_signed. This attribute
1027 should only be read when Type.is_scalar is True, and will be True
1028 for signed types, and False for all other types. Attempting to
1029 read this attribute for non-scalar types will raise a ValueError.
1031 ** It is now possible to add GDB/MI commands implemented in Python.
1033 * New features in the GDB remote stub, GDBserver
1035 ** GDBserver is now supported on OpenRISC GNU/Linux.
1037 * New native configurations
1039 GNU/Linux/OpenRISC or1k*-*-linux*
1041 *** Changes in GDB 11
1043 * The 'set disassembler-options' command now supports specifying options
1046 * GDB now supports general memory tagging functionality if the underlying
1047 architecture supports the proper primitives and hooks. Currently this is
1048 enabled only for AArch64 MTE.
1052 - Additional information when the inferior crashes with a SIGSEGV caused by
1053 a memory tag violation.
1055 - A new modifier 'm' for the "x" command, which displays allocation tags for a
1056 particular memory range.
1058 - Display of memory tag mismatches by "print", for addresses and
1059 pointers, if memory tagging is supported by the architecture.
1061 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
1066 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
1068 The MI -break-insert and -dprintf-insert commands now support a
1069 new "--qualified" option that makes GDB interpret a specified
1070 function name as a complete fully-qualified name. This is the
1071 equivalent of the CLI's "break -qualified" and "dprintf
1074 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
1076 The MI -break-insert and -dprintf-insert commands now support a
1077 '--force-condition' flag to forcibly define a condition even when
1078 the condition is invalid at all locations of the breakpoint. This
1079 is equivalent to the '-force-condition' flag of the CLI's "break"
1082 ** '-break-condition --force'
1084 The MI -break-condition command now supports a '--force' flag to
1085 forcibly define a condition even when the condition is invalid at
1086 all locations of the selected breakpoint. This is equivalent to
1087 the '-force' flag of the CLI's "cond" command.
1089 ** '-file-list-exec-source-files [--group-by-objfile]
1090 [--basename | --dirname]
1093 The existing -file-list-exec-source-files command now takes an
1094 optional REGEXP which is used to filter the source files that are
1095 included in the results.
1097 By default REGEXP is matched against the full filename of the
1098 source file. When one of --basename or --dirname is given then
1099 REGEXP is only matched against the specified part of the full
1102 When the optional --group-by-objfile flag is used the output
1103 format is changed, the results are now a list of object files
1104 (executable and libraries) with the source files that are
1105 associated with each object file.
1107 The results from -file-list-exec-source-files now include a
1108 'debug-fully-read' field which takes the value 'true' or 'false'.
1109 A 'true' value indicates the source file is from a compilation
1110 unit that has had its debug information fully read in by GDB, a
1111 value of 'false' indicates GDB has only performed a partial scan
1112 of the debug information so far.
1114 * GDB now supports core file debugging for x86_64 Cygwin programs.
1116 * GDB will now look for the .gdbinit file in a config directory before
1117 looking for ~/.gdbinit. The file is searched for in the following
1118 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
1119 $HOME/.gdbinit. On Apple hosts the search order is instead:
1120 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
1122 * GDB now supports fixed point types which are described in DWARF
1123 as base types with a fixed-point encoding. Additionally, support
1124 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
1127 For Ada, this allows support for fixed point types without requiring
1128 the use of the GNAT encoding (based on information added to the type's
1129 name following a GNAT-specific format).
1131 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
1132 or ~/.gdbearlyinit if these files are present. These files are
1133 processed earlier than any of the other initialization files and
1134 can affect parts of GDB's startup that previously had already been
1135 completed before the initialization files were read, for example
1136 styling of the initial GDB greeting.
1138 * GDB now has two new options "--early-init-command" and
1139 "--early-init-eval-command" with corresponding short options "-eix"
1140 and "-eiex" that allow options (that would normally appear in a
1141 gdbearlyinit file) to be passed on the command line.
1143 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
1144 now understood by GDB, and can be used to describe the vector
1145 registers of a target. The precise requirements of this register
1146 feature are documented in the GDB manual.
1148 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
1149 supported by GDB and describes a new VPR register from the ARM MVE
1150 (Helium) extension. See the GDB manual for more information.
1154 ** TUI windows now support mouse actions. The mouse wheel scrolls
1155 the appropriate window.
1157 ** Key combinations that do not have a specific action on the
1158 focused window are passed to GDB. For example, you now can use
1159 Ctrl-Left/Ctrl-Right to move between words in the command window
1160 regardless of which window is in focus. Previously you would
1161 need to focus on the command window for such key combinations to
1166 set debug event-loop
1167 show debug event-loop
1168 Control the display of debug output about GDB's event loop.
1170 set print memory-tag-violations
1171 show print memory-tag-violations
1172 Control whether to display additional information about memory tag violations
1173 when printing pointers and addresses. Architecture support for memory
1174 tagging is required for this option to have an effect.
1176 maintenance flush symbol-cache
1177 maintenance flush register-cache
1178 These new commands are equivalent to the already existing commands
1179 'maintenance flush-symbol-cache' and 'flushregs' respectively.
1181 maintenance flush dcache
1182 A new command to flush the dcache.
1184 maintenance info target-sections
1185 Print GDB's internal target sections table.
1187 maintenance info jit
1188 Print the JIT code objects in the inferior known to GDB.
1190 memory-tag show-logical-tag POINTER
1191 Print the logical tag for POINTER.
1192 memory-tag with-logical-tag POINTER TAG
1193 Print POINTER with logical tag TAG.
1194 memory-tag show-allocation-tag ADDRESS
1195 Print the allocation tag for ADDRESS.
1196 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1197 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1198 memory-tag check POINTER
1199 Validate that POINTER's logical tag matches the allocation tag.
1201 set startup-quietly on|off
1202 show startup-quietly
1203 When 'on', this causes GDB to act as if "-silent" were passed on the
1204 command line. This command needs to be added to an early
1205 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1208 set print type hex on|off
1210 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1211 and offsets of struct members. When 'off', decimal notation is used.
1213 set python ignore-environment on|off
1214 show python ignore-environment
1215 When 'on', this causes GDB's builtin Python to ignore any
1216 environment variables that would otherwise affect how Python
1217 behaves. This command needs to be added to an early initialization
1218 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1220 set python dont-write-bytecode auto|on|off
1221 show python dont-write-bytecode
1222 When 'on', this causes GDB's builtin Python to not write any
1223 byte-code (.pyc files) to disk. This command needs to be added to
1224 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1225 order to affect GDB. When 'off' byte-code will always be written.
1226 When set to 'auto' (the default) Python will check the
1227 PYTHONDONTWRITEBYTECODE environment variable.
1231 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1232 [-force-condition] [if CONDITION]
1233 This command would previously refuse setting a breakpoint if the
1234 CONDITION expression is invalid at a location. It now accepts and
1235 defines the breakpoint if there is at least one location at which
1236 the CONDITION is valid. The locations for which the CONDITION is
1237 invalid, are automatically disabled. If CONDITION is invalid at all
1238 of the locations, setting the breakpoint is still rejected. However,
1239 the '-force-condition' flag can be used in this case for forcing GDB to
1240 define the breakpoint, making all the current locations automatically
1241 disabled. This may be useful if the user knows the condition will
1242 become meaningful at a future location, e.g. due to a shared library
1245 condition [-force] N COND
1246 The behavior of this command is changed the same way for the 'break'
1247 command as explained above. The '-force' flag can be used to force
1248 GDB into defining the condition even when COND is invalid for all the
1249 current locations of breakpoint N.
1252 maintenance flush-symbol-cache
1253 These commands are deprecated in favor of the new commands
1254 'maintenance flush register-cache' and 'maintenance flush
1255 symbol-cache' respectively.
1257 set style version foreground COLOR
1258 set style version background COLOR
1259 set style version intensity VALUE
1260 Control the styling of GDB's version number text.
1263 When the ID parameter is omitted, then this command prints information
1264 about the current inferior. When the ID parameter is present, the
1265 behavior of the command is unchanged and have the inferior ID become
1266 the current inferior.
1268 maintenance info sections
1269 The ALLOBJ keyword has been replaced with an -all-objects command
1270 line flag. It is now possible to filter which sections are printed
1271 even when -all-objects is passed.
1273 ptype[/FLAGS] TYPE | EXPRESSION
1274 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
1275 notation is used when printing sizes and offsets of struct members.
1276 When '/d' is set, decimal notation is used when printing sizes and
1277 offsets of struct members. Default behavior is given by 'show print
1281 The info sources command output has been restructured. The results
1282 are now based around a list of objfiles (executable and libraries),
1283 and for each objfile the source files that are part of that objfile
1286 * Removed targets and native configurations
1288 ARM Symbian arm*-*-symbianelf*
1290 * New remote packets
1293 Request the remote to send allocation tags for a particular memory range.
1295 Request the remote to store the specified allocation tags to the requested
1300 ** Improved support for rvalue reference values:
1301 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1302 value-referenced-value procedure now handles rvalue reference
1305 ** New procedures for obtaining value variants:
1306 value-reference-value, value-rvalue-reference-value and
1309 ** Temporary breakpoints can now be created with make-breakpoint and
1310 tested for using breakpoint-temporary?.
1314 ** Inferior objects now contain a read-only 'connection_num' attribute that
1315 gives the connection number as seen in 'info connections' and
1318 ** New method gdb.Frame.level() which returns the stack level of the
1321 ** New method gdb.PendingFrame.level() which returns the stack level
1322 of the frame object.
1324 ** When hitting a catchpoint, the Python API will now emit a
1325 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1326 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1328 ** Python TUI windows can now receive mouse click events. If the
1329 Window object implements the click method, it is called for each
1330 mouse click event in this window.
1332 *** Changes in GDB 10
1334 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1335 and "org.gnu.gdb.arc.aux". The old names are still supported but
1336 must be considered obsolete. They will be deprecated after some
1339 * Help and apropos commands will now show the documentation of a
1340 command only once, even if that command has one or more aliases.
1341 These commands now show the command name, then all of its aliases,
1342 and finally the description of the command.
1344 * 'help aliases' now shows only the user defined aliases. GDB predefined
1345 aliases are shown together with their aliased command.
1347 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1348 debugging information as well as source code.
1350 When built with debuginfod, GDB can automatically query debuginfod
1351 servers for the separate debug files and source code of the executable
1354 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1355 requires libdebuginfod, the debuginfod client library).
1357 debuginfod is distributed with elfutils, starting with version 0.178.
1359 You can get the latest version from https://sourceware.org/elfutils.
1361 * Multi-target debugging support
1363 GDB now supports debugging multiple target connections
1364 simultaneously. For example, you can now have each inferior
1365 connected to different remote servers running in different machines,
1366 or have one inferior debugging a local native process, an inferior
1367 debugging a core dump, etc.
1369 This support is experimental and comes with some limitations -- you
1370 can only resume multiple targets simultaneously if all targets
1371 support non-stop mode, and all remote stubs or servers must support
1372 the same set of remote protocol features exactly. See also "info
1373 connections" and "add-inferior -no-connection" below, and "maint set
1374 target-non-stop" in the user manual.
1376 * New features in the GDB remote stub, GDBserver
1378 ** GDBserver is now supported on ARC GNU/Linux.
1380 ** GDBserver is now supported on RISC-V GNU/Linux.
1382 ** GDBserver no longer supports these host triplets:
1384 i[34567]86-*-lynxos*
1393 i[34567]86-*-mingw32ce*
1395 * Debugging MS-Windows processes now sets $_exitsignal when the
1396 inferior is terminated by a signal, instead of setting $_exitcode.
1398 * Multithreaded symbol loading has now been enabled by default on systems
1399 that support it (see entry for GDB 9, below), providing faster
1400 performance for programs with many symbols.
1402 * The $_siginfo convenience variable now also works on Windows targets,
1403 and will display the EXCEPTION_RECORD of the last handled exception.
1405 * TUI windows can now be arranged horizontally.
1407 * The command history filename can now be set to the empty string
1408 either using 'set history filename' or by setting 'GDBHISTFILE=' in
1409 the environment. The effect of setting this filename to the empty
1410 string is that GDB will not try to load any previous command
1413 * On Windows targets, it is now possible to debug 32-bit programs with a
1418 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1419 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1420 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
1421 running process, this new option indicates whether to detect
1422 a mismatch between the current executable file loaded by GDB and the
1423 executable file used to start the process. If 'ask', the default,
1424 display a warning and ask the user whether to load the process
1425 executable file; if 'warn', just display a warning; if 'off', don't
1426 attempt to detect a mismatch.
1428 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1429 Define a new TUI layout, specifying its name and the windows that
1432 maintenance print xml-tdesc [FILE]
1433 Prints the current target description as an XML document. If the
1434 optional FILE is provided (which is an XML target description) then
1435 the target description is read from FILE into GDB, and then
1438 maintenance print core-file-backed-mappings
1439 Prints file-backed mappings loaded from a core file's note section.
1440 Output is expected to be similar to that of "info proc mappings".
1442 set debug fortran-array-slicing on|off
1443 show debug fortran-array-slicing
1444 Print debugging when taking slices of Fortran arrays.
1446 set fortran repack-array-slices on|off
1447 show fortran repack-array-slices
1448 When taking slices from Fortran arrays and strings, if the slice is
1449 non-contiguous within the original value then, when this option is
1450 on, the new value will be repacked into a single contiguous value.
1451 When this option is off, then the value returned will consist of a
1452 descriptor that describes the slice within the memory of the
1453 original parent value.
1457 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1458 The alias command can now specify default args for an alias.
1459 GDB automatically prepends the alias default args to the argument list
1460 provided explicitly by the user.
1461 For example, to have a backtrace with full details, you can define
1462 an alias 'bt_ALL' as
1463 'alias bt_ALL = backtrace -entry-values both -frame-arg all
1464 -past-main -past-entry -full'.
1465 Alias default arguments can also use a set of nested 'with' commands,
1466 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1467 defines the alias pp10 that will pretty print a maximum of 10 elements
1468 of the given expression (if the expression is an array).
1472 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
1473 BPF bpf-unknown-none
1478 ** gdb.register_window_type can be used to implement new TUI windows
1481 ** Dynamic types can now be queried. gdb.Type has a new attribute,
1482 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
1483 field of a dynamic type may have None for its "bitpos" attribute
1486 ** Commands written in Python can be in the "TUI" help class by
1487 registering with the new constant gdb.COMMAND_TUI.
1489 ** New method gdb.PendingFrame.architecture () to retrieve the
1490 architecture of the pending frame.
1492 ** New gdb.Architecture.registers method that returns a
1493 gdb.RegisterDescriptorIterator object, an iterator that returns
1494 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
1495 way to query the registers available for an architecture.
1497 ** New gdb.Architecture.register_groups method that returns a
1498 gdb.RegisterGroupIterator object, an iterator that returns
1499 gdb.RegisterGroup objects. The new RegisterGroup is a way to
1500 discover the available register groups.
1504 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1506 ** Procedures 'memory-port-read-buffer-size',
1507 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1508 and 'set-memory-port-write-buffer-size!' are deprecated. When
1509 using Guile 2.2 and later, users who need to control the size of
1510 a memory port's internal buffer can use the 'setvbuf' procedure.
1512 *** Changes in GDB 9
1514 * 'thread-exited' event is now available in the annotations interface.
1516 * New built-in convenience variables $_gdb_major and $_gdb_minor
1517 provide the GDB version. They are handy for conditionally using
1518 features available only in or since specific GDB versions, in
1519 scripts that should work error-free with many different versions,
1520 such as in system-wide init files.
1522 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1523 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1524 of the GDB settings and the GDB maintenance settings. They are handy
1525 for changing the logic of user defined commands depending on the
1526 current GDB settings.
1528 * GDB now supports Thread Local Storage (TLS) variables on several
1529 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1530 architectures require kernel changes. TLS is not yet supported for
1531 amd64 and i386 process core dumps.
1533 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1534 addresses that required unmasking are shown in the backtrace with the
1537 * Two new convenience functions $_cimag and $_creal that extract the
1538 imaginary and real parts respectively from complex numbers.
1540 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1541 provide the exitcode or exit status of the shell commands launched by
1542 GDB commands such as "shell", "pipe" and "make".
1544 * The command define-prefix can now define user defined prefix commands.
1545 User defined commands can now be defined using these user defined prefix
1548 * Command names can now use the . character.
1550 * The RX port now supports XML target descriptions.
1552 * GDB now shows the Ada task names at more places, e.g. in task switching
1555 * GDB can now be compiled with Python 3 on Windows.
1557 * New convenience variable $_ada_exception holds the address of the
1558 Ada exception being thrown. This is set by Ada-related catchpoints.
1560 * GDB can now place breakpoints on nested functions and subroutines in
1561 Fortran code. The '::' operator can be used between parent and
1562 child scopes when placing breakpoints, for example:
1564 (gdb) break outer_function::inner_function
1566 The 'outer_function::' prefix is only needed if 'inner_function' is
1567 not visible in the current scope.
1569 * In addition to the system-wide gdbinit file, if configured with
1570 --with-system-gdbinit-dir, GDB will now also load files in that directory
1571 as system gdbinit files, unless the -nx or -n flag is provided. Files
1572 with extensions .gdb, .py and .scm are supported as long as GDB was
1573 compiled with support for that language.
1575 * GDB now supports multithreaded symbol loading for higher performance.
1576 This feature is still in testing, so it is disabled by default. You
1577 can turn it on using 'maint set worker-threads unlimited'.
1581 ** The gdb.Value type has a new method 'format_string' which returns a
1582 string representing the value. The formatting is controlled by the
1583 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1584 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1585 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1587 ** gdb.Type has a new property 'objfile' which returns the objfile the
1588 type was defined in.
1590 ** The frame information printed by the python frame filtering code
1591 is now consistent with what the 'backtrace' command prints when
1592 there are no filters, or when the 'backtrace' '-no-filters' option
1595 ** The new function gdb.lookup_static_symbol can be used to look up
1596 symbols with static linkage.
1598 ** The new function gdb.lookup_static_symbols can be used to look up
1599 all static symbols with static linkage.
1601 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1602 'lookup_static_symbol' to lookup a symbol from this objfile only.
1604 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1605 this block (e.g. block['local_variable']).
1609 | [COMMAND] | SHELL_COMMAND
1610 | -d DELIM COMMAND DELIM SHELL_COMMAND
1611 pipe [COMMAND] | SHELL_COMMAND
1612 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1613 Executes COMMAND and sends its output to SHELL_COMMAND.
1614 With no COMMAND, repeat the last executed command
1615 and send its output to SHELL_COMMAND.
1617 define-prefix COMMAND
1618 Define or mark a command as a user-defined prefix command.
1620 with SETTING [VALUE] [-- COMMAND]
1621 w SETTING [VALUE] [-- COMMAND]
1622 Temporarily set SETTING, run COMMAND, and restore SETTING.
1623 Usage: with SETTING -- COMMAND
1624 With no COMMAND, repeats the last executed command.
1625 SETTING is any GDB setting you can change with the "set"
1626 subcommands. For example, 'with language c -- print someobj'
1627 temporarily switches to the C language in order to print someobj.
1628 Settings can be combined: 'w lang c -- w print elements unlimited --
1629 usercmd' switches to the C language and runs usercmd with no limit
1630 of array elements to print.
1632 maint with SETTING [VALUE] [-- COMMAND]
1633 Like "with", but works with "maintenance set" settings.
1635 set may-call-functions [on|off]
1636 show may-call-functions
1637 This controls whether GDB will attempt to call functions in
1638 the program, such as with expressions in the print command. It
1639 defaults to on. Calling functions in the program being debugged
1640 can have undesired side effects. It is now possible to forbid
1641 such function calls. If function calls are forbidden, GDB will throw
1642 an error when a command (such as print expression) calls a function
1645 set print finish [on|off]
1647 This controls whether the `finish' command will display the value
1648 that is returned by the current function. When `off', the value is
1649 still entered into the value history, but it is not printed. The
1653 show print max-depth
1654 Allows deeply nested structures to be simplified when printing by
1655 replacing deeply nested parts (beyond the max-depth) with ellipses.
1656 The default max-depth is 20, but this can be set to unlimited to get
1657 the old behavior back.
1659 set print raw-values [on|off]
1660 show print raw-values
1661 By default, GDB applies the enabled pretty printers when printing a
1662 value. This allows to ignore the enabled pretty printers for a series
1663 of commands. The default is 'off'.
1665 set logging debugredirect [on|off]
1666 By default, GDB debug output will go to both the terminal and the logfile.
1667 Set if you want debug output to go only to the log file.
1669 set style title foreground COLOR
1670 set style title background COLOR
1671 set style title intensity VALUE
1672 Control the styling of titles.
1674 set style highlight foreground COLOR
1675 set style highlight background COLOR
1676 set style highlight intensity VALUE
1677 Control the styling of highlightings.
1679 maint set worker-threads
1680 maint show worker-threads
1681 Control the number of worker threads that can be used by GDB. The
1682 default is 0. "unlimited" lets GDB choose a number that is
1683 reasonable. Currently worker threads are only used when demangling
1684 the names of linker symbols.
1686 set style tui-border foreground COLOR
1687 set style tui-border background COLOR
1688 Control the styling of TUI borders.
1690 set style tui-active-border foreground COLOR
1691 set style tui-active-border background COLOR
1692 Control the styling of the active TUI border.
1694 maint set test-settings KIND
1695 maint show test-settings KIND
1696 A set of commands used by the testsuite for exercising the settings
1699 maint set tui-resize-message [on|off]
1700 maint show tui-resize-message
1701 Control whether GDB prints a message each time the terminal is
1702 resized when in TUI mode. This is primarily useful for testing the
1705 set print frame-info [short-location|location|location-and-address
1706 |source-and-location|source-line|auto]
1707 show print frame-info
1708 This controls what frame information is printed by the commands printing
1709 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1710 'frame', 'stepi'. The python frame filtering also respect this setting.
1711 The 'backtrace' '-frame-info' option can override this global setting.
1713 set tui compact-source
1714 show tui compact-source
1716 Enable the "compact" display mode for the TUI source window. The
1717 compact display uses only as much space as is needed for the line
1718 numbers in the current file, and only a single space to separate the
1719 line numbers from the source.
1721 info modules [-q] [REGEXP]
1722 Return a list of Fortran modules matching REGEXP, or all modules if
1725 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1726 Return a list of functions within all modules, grouped by module.
1727 The list of functions can be restricted with the optional regular
1728 expressions. MODULE_REGEXP matches against the module name,
1729 TYPE_REGEXP matches against the function type signature, and REGEXP
1730 matches against the function name.
1732 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1733 Return a list of variables within all modules, grouped by module.
1734 The list of variables can be restricted with the optional regular
1735 expressions. MODULE_REGEXP matches against the module name,
1736 TYPE_REGEXP matches against the variable type, and REGEXP matches
1737 against the variable name.
1739 set debug remote-packet-max-chars
1740 show debug remote-packet-max-chars
1741 Controls the number of characters to output in a remote packet when using
1743 The default is 512 bytes.
1746 Lists the target connections currently in use.
1751 The "help" command uses the title style to enhance the
1752 readibility of its output by styling the classes and
1756 Similarly to "help", the "apropos" command also uses the
1757 title style for the command names. "apropos" accepts now
1758 a flag "-v" (verbose) to show the full documentation
1759 of matching commands and to use the highlight style to mark
1760 the documentation parts matching REGEXP.
1764 The GDB printf and eval commands can now print C-style and Ada-style
1765 string convenience variables without calling functions in the program.
1766 This allows to do formatted printing of strings without having
1767 a running inferior, or when debugging a core dump.
1769 info sources [-dirname | -basename] [--] [REGEXP]
1770 This command has now optional arguments to only print the files
1771 whose names match REGEXP. The arguments -dirname and -basename
1772 allow to restrict matching respectively to the dirname and basename
1776 The "show style" and its subcommands are now styling
1777 a style name in their output using its own style, to help
1778 the user visualize the different styles.
1780 set print frame-arguments
1781 The new value 'presence' indicates to only indicate the presence of
1782 arguments using ..., instead of printing argument names and values.
1784 set print raw-frame-arguments
1785 show print raw-frame-arguments
1787 These commands replace the similarly-named "set/show print raw
1788 frame-arguments" commands (now with a dash instead of a space). The
1789 old commands are now deprecated and may be removed in a future
1792 add-inferior [-no-connection]
1793 The add-inferior command now supports a "-no-connection" flag that
1794 makes the new inferior start with no target connection associated.
1795 By default, the new inferior inherits the target connection of the
1796 current inferior. See also "info connections".
1799 This command's output now includes a new "Connection" column
1800 indicating which target connection an inferior is bound to. See
1801 "info connections" above.
1803 maint test-options require-delimiter
1804 maint test-options unknown-is-error
1805 maint test-options unknown-is-operand
1806 maint show test-options-completion-result
1807 Commands used by the testsuite to validate the command options
1810 focus, winheight, +, -, >, <
1811 These commands are now case-sensitive.
1813 * New command options, command completion
1815 GDB now has a standard infrastructure to support dash-style command
1816 options ('-OPT'). One benefit is that commands that use it can
1817 easily support completion of command line arguments. Try "CMD
1818 -[TAB]" or "help CMD" to find options supported by a command. Over
1819 time, we intend to migrate most commands to this infrastructure. A
1820 number of commands got support for new command options in this
1823 ** The "print" and "compile print" commands now support a number of
1824 options that allow overriding relevant global print settings as
1825 set by "set print" subcommands:
1829 -array-indexes [on|off]
1830 -elements NUMBER|unlimited
1834 -raw-values [on|off]
1835 -repeats NUMBER|unlimited
1836 -static-members [on|off]
1841 Note that because the "print"/"compile print" commands accept
1842 arbitrary expressions which may look like options (including
1843 abbreviations), if you specify any command option, then you must
1844 use a double dash ("--") to mark the end of argument processing.
1846 ** The "backtrace" command now supports a number of options that
1847 allow overriding relevant global print settings as set by "set
1848 backtrace" and "set print" subcommands:
1850 -entry-values no|only|preferred|if-needed|both|compact|default
1851 -frame-arguments all|scalars|none
1852 -raw-frame-arguments [on|off]
1853 -frame-info auto|source-line|location|source-and-location
1854 |location-and-address|short-location
1856 -past-entry [on|off]
1858 In addition, the full/no-filters/hide qualifiers are now also
1859 exposed as command options too:
1865 ** The "frame apply", "tfaas" and "faas" commands similarly now
1866 support the following options:
1869 -past-entry [on|off]
1871 ** The new "info sources" options -dirname and -basename options
1872 are using the standard '-OPT' infrastructure.
1874 All options above can also be abbreviated. The argument of boolean
1875 (on/off) options can be 0/1 too, and also the argument is assumed
1876 "on" if omitted. This allows writing compact command invocations,
1879 (gdb) p -ra -p -o 0 -- *myptr
1881 The above is equivalent to:
1883 (gdb) print -raw-values -pretty -object off -- *myptr
1885 ** The "info types" command now supports the '-q' flag to disable
1886 printing of some header information in a similar fashion to "info
1887 variables" and "info functions".
1889 ** The "info variables", "info functions", and "whereis" commands
1890 now take a '-n' flag that excludes non-debug symbols (symbols
1891 from the symbol table, not from the debug info such as DWARF)
1894 * Completion improvements
1896 ** GDB can now complete the options of the "thread apply all" and
1897 "taas" commands, and their "-ascending" option can now be
1900 ** GDB can now complete the options of the "info threads", "info
1901 functions", "info variables", "info locals", and "info args"
1904 ** GDB can now complete the options of the "compile file" and
1905 "compile code" commands. The "compile file" command now
1906 completes on filenames.
1908 ** GDB can now complete the backtrace command's
1909 "full/no-filters/hide" qualifiers.
1911 * In settings, you can now abbreviate "unlimited".
1913 E.g., "set print elements u" is now equivalent to "set print
1914 elements unlimited".
1919 This lists all the possible completions for the rest of the line, if it
1920 were to be given as a command itself. This is intended for use by MI
1921 frontends in cases when separate CLI and MI channels cannot be used.
1923 -catch-throw, -catch-rethrow, and -catch-catch
1924 These can be used to catch C++ exceptions in a similar fashion to
1925 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1927 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1928 These commands are the MI equivalent of the CLI commands 'info
1929 functions', 'info types', and 'info variables' respectively.
1931 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1934 -symbol-info-module-functions and -symbol-info-module-variables.
1935 These commands are the MI equivalent of the CLI commands 'info
1936 module functions' and 'info module variables'.
1940 ** The default version of the MI interpreter is now 3 (-i=mi3).
1942 ** The output of information about multi-location breakpoints (which is
1943 syntactically incorrect in MI 2) has changed in MI 3. This affects
1944 the following commands and events:
1948 - =breakpoint-created
1949 - =breakpoint-modified
1951 The -fix-multi-location-breakpoint-output command can be used to enable
1952 this behavior with previous MI versions.
1954 ** Backtraces and frames include a new optional field addr_flags which is
1955 given after the addr field. On AArch64 this contains PAC if the address
1956 has been masked in the frame. On all other targets the field is not
1961 The testsuite now creates the files gdb.cmd (containing the arguments
1962 used to launch GDB) and gdb.in (containing all the commands sent to
1963 GDB) in the output directory for each test script. Multiple invocations
1964 are appended with .1, .2, .3 etc.
1966 * Building GDB and GDBserver now requires GNU make >= 3.82.
1968 Using another implementation of the make program or an earlier version of
1969 GNU make to build GDB or GDBserver is not supported.
1971 * Building GDB now requires GNU readline >= 7.0.
1973 GDB now bundles GNU readline 8.0, but if you choose to use
1974 --with-system-readline, only readline >= 7.0 can be used.
1976 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1977 from .inputrc to bind keys in this keymap. This feature is only
1978 available when gdb is built against GNU readline 8.0 or later.
1980 * Removed targets and native configurations
1982 GDB no longer supports debugging the Cell Broadband Engine. This includes
1983 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1984 of Cell/B.E. applications that use both the PPU and SPU architectures.
1990 * Removed targets and native configurations
1992 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1993 sparc*-*-solaris2.10
1995 *** Changes in GDB 8.3
1997 * GDB and GDBserver now support access to additional registers on
1998 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
2001 * GDB now has experimental support for the compilation and injection of
2002 C++ source code into the inferior. This beta release does not include
2003 support for several language features, such as templates, constructors,
2006 This feature requires GCC 7.1 or higher built with libcp1.so
2009 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
2010 can be passed using the '[ADDRESS]:PORT' notation, or the regular
2011 'ADDRESS:PORT' method.
2013 * DWARF index cache: GDB can now automatically save indices of DWARF
2014 symbols on disk to speed up further loading of the same binaries.
2016 * Ada task switching is now supported on aarch64-elf targets when
2017 debugging a program using the Ravenscar Profile. For more information,
2018 see the "Tasking Support when using the Ravenscar Profile" section
2019 in the GDB user manual.
2021 * GDB in batch mode now exits with status 1 if the last command to be
2024 * The RISC-V target now supports target descriptions.
2026 * System call catchpoints now support system call aliases on FreeBSD.
2027 When the ABI of a system call changes in FreeBSD, this is
2028 implemented by leaving a compatibility system call using the old ABI
2029 at the existing number and allocating a new system call number for
2030 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
2031 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
2032 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
2033 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
2034 so that a system call catchpoint for the 'kevent' system call will
2035 catch invocations of both the 'kevent' and 'freebsd11_kevent'
2036 binaries. This ensures that 'kevent' system calls are caught for
2037 binaries using either the old or new ABIs.
2039 * Terminal styling is now available for the CLI and the TUI. GNU
2040 Source Highlight can additionally be used to provide styling of
2041 source code snippets. See the "set style" commands, below, for more
2044 * Removed support for old demangling styles arm, edg, gnu, hp and
2049 set debug compile-cplus-types
2050 show debug compile-cplus-types
2051 Control the display of debug output about type conversion in the
2052 C++ compile feature. Commands have no effect while compiling
2053 for other languages.
2057 Control whether debug output about files/functions skipping is
2060 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
2061 Apply a command to some frames.
2062 FLAG arguments allow to control what output to produce and how to handle
2063 errors raised when applying COMMAND to a frame.
2066 Apply a command to all threads (ignoring errors and empty output).
2067 Shortcut for 'thread apply all -s COMMAND'.
2070 Apply a command to all frames (ignoring errors and empty output).
2071 Shortcut for 'frame apply all -s COMMAND'.
2074 Apply a command to all frames of all threads (ignoring errors and empty
2076 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
2078 maint set dwarf unwinders (on|off)
2079 maint show dwarf unwinders
2080 Control whether DWARF unwinders can be used.
2083 Display a list of open files for a process.
2087 Changes to the "frame", "select-frame", and "info frame" CLI commands.
2088 These commands all now take a frame specification which
2089 is either a frame level, or one of the keywords 'level', 'address',
2090 'function', or 'view' followed by a parameter. Selecting a frame by
2091 address, or viewing a frame outside the current backtrace now
2092 requires the use of a keyword. Selecting a frame by level is
2093 unchanged. The MI comment "-stack-select-frame" is unchanged.
2095 target remote FILENAME
2096 target extended-remote FILENAME
2097 If FILENAME is a Unix domain socket, GDB will attempt to connect
2098 to this socket instead of opening FILENAME as a character device.
2100 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2101 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2102 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2103 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2104 These commands can now print only the searched entities
2105 matching the provided regexp(s), giving a condition
2106 on the entity names or entity types. The flag -q disables
2107 printing headers or informations messages.
2113 These commands now determine the syntax for the shown entities
2114 according to the language chosen by `set language'. In particular,
2115 `set language auto' means to automatically choose the language of
2118 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
2119 The 'thread apply' command accepts new FLAG arguments.
2120 FLAG arguments allow to control what output to produce and how to handle
2121 errors raised when applying COMMAND to a thread.
2123 set tui tab-width NCHARS
2124 show tui tab-width NCHARS
2125 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
2127 set style enabled [on|off]
2129 Enable or disable terminal styling. Styling is enabled by default
2130 on most hosts, but disabled by default when in batch mode.
2132 set style sources [on|off]
2134 Enable or disable source code styling. Source code styling is
2135 enabled by default, but only takes effect if styling in general is
2136 enabled, and if GDB was linked with GNU Source Highlight.
2138 set style filename foreground COLOR
2139 set style filename background COLOR
2140 set style filename intensity VALUE
2141 Control the styling of file names.
2143 set style function foreground COLOR
2144 set style function background COLOR
2145 set style function intensity VALUE
2146 Control the styling of function names.
2148 set style variable foreground COLOR
2149 set style variable background COLOR
2150 set style variable intensity VALUE
2151 Control the styling of variable names.
2153 set style address foreground COLOR
2154 set style address background COLOR
2155 set style address intensity VALUE
2156 Control the styling of addresses.
2160 ** The '-data-disassemble' MI command now accepts an '-a' option to
2161 disassemble the whole function surrounding the given program
2162 counter value or function name. Support for this feature can be
2163 verified by using the "-list-features" command, which should
2164 contain "data-disassemble-a-option".
2166 ** Command responses and notifications that include a frame now include
2167 the frame's architecture in a new "arch" attribute.
2169 * New native configurations
2171 GNU/Linux/RISC-V riscv*-*-linux*
2172 FreeBSD/riscv riscv*-*-freebsd*
2176 GNU/Linux/RISC-V riscv*-*-linux*
2177 CSKY ELF csky*-*-elf
2178 CSKY GNU/LINUX csky*-*-linux
2179 FreeBSD/riscv riscv*-*-freebsd*
2181 GNU/Linux/OpenRISC or1k*-*-linux*
2185 GDB no longer supports native debugging on versions of MS-Windows
2190 ** GDB no longer supports Python versions less than 2.6.
2192 ** The gdb.Inferior type has a new 'progspace' property, which is the program
2193 space associated to that inferior.
2195 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2196 of objfiles associated to that program space.
2198 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2199 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2202 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2203 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
2204 correct and did not work properly.
2206 ** The gdb.Value type has a new constructor, which is used to construct a
2207 gdb.Value from a Python buffer object and a gdb.Type.
2213 Enable or disable the undefined behavior sanitizer. This is
2214 disabled by default, but passing --enable-ubsan=yes or
2215 --enable-ubsan=auto to configure will enable it. Enabling this can
2216 cause a performance penalty. The undefined behavior sanitizer was
2217 first introduced in GCC 4.9.
2219 *** Changes in GDB 8.2
2221 * The 'set disassembler-options' command now supports specifying options
2222 for the MIPS target.
2224 * The 'symbol-file' command now accepts an '-o' option to add a relative
2225 offset to all sections.
2227 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2228 a relative offset to all sections, but it allows to override the load
2229 address of individual sections using '-s'.
2231 * The 'add-symbol-file' command no longer requires the second argument
2232 (address of the text section).
2234 * The endianness used with the 'set endian auto' mode in the absence of
2235 an executable selected for debugging is now the last endianness chosen
2236 either by one of the 'set endian big' and 'set endian little' commands
2237 or by inferring from the last executable used, rather than the startup
2240 * The pager now allows a "c" response, meaning to disable the pager
2241 for the rest of the current command.
2243 * The commands 'info variables/functions/types' now show the source line
2244 numbers of symbol definitions when available.
2246 * 'info proc' now works on running processes on FreeBSD systems and core
2247 files created on FreeBSD systems.
2249 * C expressions can now use _Alignof, and C++ expressions can now use
2252 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
2253 the vector length while the process is running.
2259 Control display of debugging info regarding the FreeBSD native target.
2261 set|show varsize-limit
2262 This new setting allows the user to control the maximum size of Ada
2263 objects being printed when those objects have a variable type,
2264 instead of that maximum size being hardcoded to 65536 bytes.
2266 set|show record btrace cpu
2267 Controls the processor to be used for enabling errata workarounds for
2268 branch trace decode.
2270 maint check libthread-db
2271 Run integrity checks on the current inferior's thread debugging
2274 maint set check-libthread-db (on|off)
2275 maint show check-libthread-db
2276 Control whether to run integrity checks on inferior specific thread
2277 debugging libraries as they are loaded. The default is not to
2278 perform such checks.
2282 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2284 ** The commands attached to a breakpoint can be set by assigning to
2285 the breakpoint's "commands" field.
2287 ** gdb.execute can now execute multi-line gdb commands.
2289 ** The new functions gdb.convenience_variable and
2290 gdb.set_convenience_variable can be used to get and set the value
2291 of convenience variables.
2293 ** A gdb.Parameter will no longer print the "set" help text on an
2294 ordinary "set"; instead by default a "set" will be silent unless
2295 the get_set_string method returns a non-empty string.
2299 RiscV ELF riscv*-*-elf
2301 * Removed targets and native configurations
2303 m88k running OpenBSD m88*-*-openbsd*
2304 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2305 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2306 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2308 * Aarch64/Linux hardware watchpoints improvements
2310 Hardware watchpoints on unaligned addresses are now properly
2311 supported when running Linux kernel 4.10 or higher: read and access
2312 watchpoints are no longer spuriously missed, and all watchpoints
2313 lengths between 1 and 8 bytes are supported. On older kernels,
2314 watchpoints set on unaligned addresses are no longer missed, with
2315 the tradeoff that there is a possibility of false hits being
2320 --enable-codesign=CERT
2321 This can be used to invoke "codesign -s CERT" after building gdb.
2322 This option is useful on macOS, where code signing is required for
2323 gdb to work properly.
2325 --disable-gdbcli has been removed
2326 This is now silently accepted, but does nothing.
2328 *** Changes in GDB 8.1
2330 * GDB now supports dynamically creating arbitrary register groups specified
2331 in XML target descriptions. This allows for finer grain grouping of
2332 registers on systems with a large amount of registers.
2334 * The 'ptype' command now accepts a '/o' flag, which prints the
2335 offsets and sizes of fields in a struct, like the pahole(1) tool.
2337 * New "--readnever" command line option instructs GDB to not read each
2338 symbol file's symbolic debug information. This makes startup faster
2339 but at the expense of not being able to perform symbolic debugging.
2340 This option is intended for use cases where symbolic debugging will
2341 not be used, e.g., when you only need to dump the debuggee's core.
2343 * GDB now uses the GNU MPFR library, if available, to emulate target
2344 floating-point arithmetic during expression evaluation when the target
2345 uses different floating-point formats than the host. At least version
2346 3.1 of GNU MPFR is required.
2348 * GDB now supports access to the guarded-storage-control registers and the
2349 software-based guarded-storage broadcast control registers on IBM z14.
2351 * On Unix systems, GDB now supports transmitting environment variables
2352 that are to be set or unset to GDBserver. These variables will
2353 affect the environment to be passed to the remote inferior.
2355 To inform GDB of environment variables that are to be transmitted to
2356 GDBserver, use the "set environment" command. Only user set
2357 environment variables are sent to GDBserver.
2359 To inform GDB of environment variables that are to be unset before
2360 the remote inferior is started by the GDBserver, use the "unset
2361 environment" command.
2363 * Completion improvements
2365 ** GDB can now complete function parameters in linespecs and
2366 explicit locations without quoting. When setting breakpoints,
2367 quoting around functions names to help with TAB-completion is
2368 generally no longer necessary. For example, this now completes
2371 (gdb) b function(in[TAB]
2372 (gdb) b function(int)
2374 Related, GDB is no longer confused with completing functions in
2375 C++ anonymous namespaces:
2378 (gdb) b (anonymous namespace)::[TAB][TAB]
2379 (anonymous namespace)::a_function()
2380 (anonymous namespace)::b_function()
2382 ** GDB now has much improved linespec and explicit locations TAB
2383 completion support, that better understands what you're
2384 completing and offers better suggestions. For example, GDB no
2385 longer offers data symbols as possible completions when you're
2386 setting a breakpoint.
2388 ** GDB now TAB-completes label symbol names.
2390 ** The "complete" command now mimics TAB completion accurately.
2392 * New command line options (gcore)
2395 Dump all memory mappings.
2397 * Breakpoints on C++ functions are now set on all scopes by default
2399 By default, breakpoints on functions/methods are now interpreted as
2400 specifying all functions with the given name ignoring missing
2401 leading scopes (namespaces and classes).
2403 For example, assuming a C++ program with symbols named:
2408 both commands "break func()" and "break B::func()" set a breakpoint
2411 You can use the new flag "-qualified" to override this. This makes
2412 GDB interpret the specified function name as a complete
2413 fully-qualified name instead. For example, using the same C++
2414 program, the "break -q B::func" command sets a breakpoint on
2415 "B::func", only. A parameter has been added to the Python
2416 gdb.Breakpoint constructor to achieve the same result when creating
2417 a breakpoint from Python.
2419 * Breakpoints on functions marked with C++ ABI tags
2421 GDB can now set breakpoints on functions marked with C++ ABI tags
2422 (e.g., [abi:cxx11]). See here for a description of ABI tags:
2423 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2425 Functions with a C++11 abi tag are demangled/displayed like this:
2427 function[abi:cxx11](int)
2430 You can now set a breakpoint on such functions simply as if they had
2433 (gdb) b function(int)
2435 Or if you need to disambiguate between tags, like:
2437 (gdb) b function[abi:other_tag](int)
2439 Tab completion was adjusted accordingly as well.
2443 ** New events gdb.new_inferior, gdb.inferior_deleted, and
2444 gdb.new_thread are emitted. See the manual for further
2445 description of these.
2447 ** A new function, "gdb.rbreak" has been added to the Python API.
2448 This function allows the setting of a large number of breakpoints
2449 via a regex pattern in Python. See the manual for further details.
2451 ** Python breakpoints can now accept explicit locations. See the
2452 manual for a further description of this feature.
2455 * New features in the GDB remote stub, GDBserver
2457 ** GDBserver is now able to start inferior processes with a
2458 specified initial working directory.
2460 The user can set the desired working directory to be used from
2461 GDB using the new "set cwd" command.
2463 ** New "--selftest" command line option runs some GDBserver self
2464 tests. These self tests are disabled in releases.
2466 ** On Unix systems, GDBserver now does globbing expansion and variable
2467 substitution in inferior command line arguments.
2469 This is done by starting inferiors using a shell, like GDB does.
2470 See "set startup-with-shell" in the user manual for how to disable
2471 this from GDB when using "target extended-remote". When using
2472 "target remote", you can disable the startup with shell by using the
2473 new "--no-startup-with-shell" GDBserver command line option.
2475 ** On Unix systems, GDBserver now supports receiving environment
2476 variables that are to be set or unset from GDB. These variables
2477 will affect the environment to be passed to the inferior.
2479 * When catching an Ada exception raised with a message, GDB now prints
2480 the message in the catchpoint hit notification. In GDB/MI mode, that
2481 information is provided as an extra field named "exception-message"
2482 in the *stopped notification.
2484 * Trait objects can now be inspected When debugging Rust code. This
2485 requires compiler support which will appear in Rust 1.24.
2487 * New remote packets
2489 QEnvironmentHexEncoded
2490 Inform GDBserver of an environment variable that is to be passed to
2491 the inferior when starting it.
2494 Inform GDBserver of an environment variable that is to be unset
2495 before starting the remote inferior.
2498 Inform GDBserver that the environment should be reset (i.e.,
2499 user-set environment variables should be unset).
2502 Indicates whether the inferior must be started with a shell or not.
2505 Tell GDBserver that the inferior to be started should use a specific
2508 * The "maintenance print c-tdesc" command now takes an optional
2509 argument which is the file name of XML target description.
2511 * The "maintenance selftest" command now takes an optional argument to
2512 filter the tests to be run.
2514 * The "enable", and "disable" commands now accept a range of
2515 breakpoint locations, e.g. "enable 1.3-5".
2520 Set and show the current working directory for the inferior.
2522 set|show compile-gcc
2523 Set and show compilation command used for compiling and injecting code
2524 with the 'compile' commands.
2526 set debug separate-debug-file
2527 show debug separate-debug-file
2528 Control the display of debug output about separate debug file search.
2530 set dump-excluded-mappings
2531 show dump-excluded-mappings
2532 Control whether mappings marked with the VM_DONTDUMP flag should be
2533 dumped when generating a core file.
2535 maint info selftests
2536 List the registered selftests.
2539 Start the debugged program stopping at the first instruction.
2542 Control display of debugging messages related to OpenRISC targets.
2544 set|show print type nested-type-limit
2545 Set and show the limit of nesting level for nested types that the
2546 type printer will show.
2548 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2551 * Safer/improved support for debugging with no debug info
2553 GDB no longer assumes functions with no debug information return
2556 This means that GDB now refuses to call such functions unless you
2557 tell it the function's type, by either casting the call to the
2558 declared return type, or by casting the function to a function
2559 pointer of the right type, and calling that:
2561 (gdb) p getenv ("PATH")
2562 'getenv' has unknown return type; cast the call to its declared return type
2563 (gdb) p (char *) getenv ("PATH")
2564 $1 = 0x7fffffffe "/usr/local/bin:/"...
2565 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2566 $2 = 0x7fffffffe "/usr/local/bin:/"...
2568 Similarly, GDB no longer assumes that global variables with no debug
2569 info have type 'int', and refuses to print the variable's value
2570 unless you tell it the variable's type:
2573 'var' has unknown type; cast it to its declared type
2577 * New native configurations
2579 FreeBSD/aarch64 aarch64*-*-freebsd*
2580 FreeBSD/arm arm*-*-freebsd*
2584 FreeBSD/aarch64 aarch64*-*-freebsd*
2585 FreeBSD/arm arm*-*-freebsd*
2586 OpenRISC ELF or1k*-*-elf
2588 * Removed targets and native configurations
2590 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2592 *** Changes in GDB 8.0
2594 * GDB now supports access to the PKU register on GNU/Linux. The register is
2595 added by the Memory Protection Keys for Userspace feature which will be
2596 available in future Intel CPUs.
2598 * GDB now supports C++11 rvalue references.
2602 ** New functions to start, stop and access a running btrace recording.
2603 ** Rvalue references are now supported in gdb.Type.
2605 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2608 * Building GDB and GDBserver now requires a C++11 compiler.
2610 For example, GCC 4.8 or later.
2612 It is no longer possible to build GDB or GDBserver with a C
2613 compiler. The --disable-build-with-cxx configure option has been
2616 * Building GDB and GDBserver now requires GNU make >= 3.81.
2618 It is no longer supported to build GDB or GDBserver with another
2619 implementation of the make program or an earlier version of GNU make.
2621 * Native debugging on MS-Windows supports command-line redirection
2623 Command-line arguments used for starting programs on MS-Windows can
2624 now include redirection symbols supported by native Windows shells,
2625 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2626 as "run", "start", and "set args", as well as the corresponding MI
2629 * Support for thread names on MS-Windows.
2631 GDB now catches and handles the special exception that programs
2632 running on MS-Windows use to assign names to threads in the
2635 * Support for Java programs compiled with gcj has been removed.
2637 * User commands now accept an unlimited number of arguments.
2638 Previously, only up to 10 was accepted.
2640 * The "eval" command now expands user-defined command arguments.
2642 This makes it easier to process a variable number of arguments:
2647 eval "print $arg%d", $i
2652 * Target descriptions can now describe registers for sparc32 and sparc64.
2654 * GDB now supports DWARF version 5 (debug information format).
2655 Its .debug_names index is not yet supported.
2657 * New native configurations
2659 FreeBSD/mips mips*-*-freebsd
2663 Synopsys ARC arc*-*-elf32
2664 FreeBSD/mips mips*-*-freebsd
2666 * Removed targets and native configurations
2668 Alpha running FreeBSD alpha*-*-freebsd*
2669 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2674 Erases all the flash memory regions reported by the target.
2676 maint print arc arc-instruction address
2677 Print internal disassembler information about instruction at a given address.
2681 set disassembler-options
2682 show disassembler-options
2683 Controls the passing of target specific information to the disassembler.
2684 If it is necessary to specify more than one disassembler option then
2685 multiple options can be placed together into a comma separated list.
2686 The default value is the empty string. Currently, the only supported
2687 targets are ARM, PowerPC and S/390.
2692 Erases all the flash memory regions reported by the target. This is
2693 equivalent to the CLI command flash-erase.
2695 -file-list-shared-libraries
2696 List the shared libraries in the program. This is
2697 equivalent to the CLI command "info shared".
2700 Catchpoints stopping the program when Ada exceptions are
2701 handled. This is equivalent to the CLI command "catch handlers".
2703 *** Changes in GDB 7.12
2705 * GDB and GDBserver now build with a C++ compiler by default.
2707 The --enable-build-with-cxx configure option is now enabled by
2708 default. One must now explicitly configure with
2709 --disable-build-with-cxx in order to build with a C compiler. This
2710 option will be removed in a future release.
2712 * GDBserver now supports recording btrace without maintaining an active
2715 * GDB now supports a negative repeat count in the 'x' command to examine
2716 memory backward from the given address. For example:
2719 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2720 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2721 (gdb) x/-5i 0x0000000000400580
2722 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2723 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2724 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2725 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2726 0x40057b <main(int, char**)+25>:
2727 callq 0x400536 <Func1(int, char const*)>
2729 * Fortran: Support structures with fields of dynamic types and
2730 arrays of dynamic types.
2732 * The symbol dumping maintenance commands have new syntax.
2733 maint print symbols [-pc address] [--] [filename]
2734 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2735 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2736 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2737 maint print msymbols [-objfile objfile] [--] [filename]
2739 * GDB now supports multibit bitfields and enums in target register
2742 * New Python-based convenience function $_as_string(val), which returns
2743 the textual representation of a value. This function is especially
2744 useful to obtain the text label of an enum value.
2746 * Intel MPX bound violation handling.
2748 Segmentation faults caused by a Intel MPX boundary violation
2749 now display the kind of violation (upper or lower), the memory
2750 address accessed and the memory bounds, along with the usual
2751 signal received and code location.
2755 Program received signal SIGSEGV, Segmentation fault
2756 Upper bound violation while accessing address 0x7fffffffc3b3
2757 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2758 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2760 * Rust language support.
2761 GDB now supports debugging programs written in the Rust programming
2762 language. See https://www.rust-lang.org/ for more information about
2765 * Support for running interpreters on specified input/output devices
2767 GDB now supports a new mechanism that allows frontends to provide
2768 fully featured GDB console views, as a better alternative to
2769 building such views on top of the "-interpreter-exec console"
2770 command. See the new "new-ui" command below. With that command,
2771 frontends can now start GDB in the traditional command-line mode
2772 running in an embedded terminal emulator widget, and create a
2773 separate MI interpreter running on a specified i/o device. In this
2774 way, GDB handles line editing, history, tab completion, etc. in the
2775 console all by itself, and the GUI uses the separate MI interpreter
2776 for its own control and synchronization, invisible to the command
2779 * The "catch syscall" command catches groups of related syscalls.
2781 The "catch syscall" command now supports catching a group of related
2782 syscalls using the 'group:' or 'g:' prefix.
2787 skip -gfile file-glob-pattern
2788 skip -function function
2789 skip -rfunction regular-expression
2790 A generalized form of the skip command, with new support for
2791 glob-style file names and regular expressions for function names.
2792 Additionally, a file spec and a function spec may now be combined.
2794 maint info line-table REGEXP
2795 Display the contents of GDB's internal line table data structure.
2798 Run any GDB unit tests that were compiled in.
2801 Start a new user interface instance running INTERP as interpreter,
2802 using the TTY file for input/output.
2806 ** gdb.Breakpoint objects have a new attribute "pending", which
2807 indicates whether the breakpoint is pending.
2808 ** Three new breakpoint-related events have been added:
2809 gdb.breakpoint_created, gdb.breakpoint_modified, and
2810 gdb.breakpoint_deleted.
2812 signal-event EVENTID
2813 Signal ("set") the given MS-Windows event object. This is used in
2814 conjunction with the Windows JIT debugging (AeDebug) support, where
2815 the OS suspends a crashing process until a debugger can attach to
2816 it. Resuming the crashing process, in order to debug it, is done by
2817 signalling an event.
2819 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2820 was added in GDBserver, including JIT compiling fast tracepoint's
2821 conditional expression bytecode into native code.
2823 * Support for various remote target protocols and ROM monitors has
2826 target m32rsdi Remote M32R debugging over SDI
2827 target mips MIPS remote debugging protocol
2828 target pmon PMON ROM monitor
2829 target ddb NEC's DDB variant of PMON for Vr4300
2830 target rockhopper NEC RockHopper variant of PMON
2831 target lsi LSI variant of PMO
2833 * Support for tracepoints and fast tracepoints on powerpc-linux,
2834 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2835 including JIT compiling fast tracepoint's conditional expression
2836 bytecode into native code.
2838 * MI async record =record-started now includes the method and format used for
2839 recording. For example:
2841 =record-started,thread-group="i1",method="btrace",format="bts"
2843 * MI async record =thread-selected now includes the frame field. For example:
2845 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2849 Andes NDS32 nds32*-*-elf
2851 *** Changes in GDB 7.11
2853 * GDB now supports debugging kernel-based threads on FreeBSD.
2855 * Per-inferior thread numbers
2857 Thread numbers are now per inferior instead of global. If you're
2858 debugging multiple inferiors, GDB displays thread IDs using a
2859 qualified INF_NUM.THR_NUM form. For example:
2863 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2864 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2865 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2866 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2868 As consequence, thread numbers as visible in the $_thread
2869 convenience variable and in Python's InferiorThread.num attribute
2870 are no longer unique between inferiors.
2872 GDB now maintains a second thread ID per thread, referred to as the
2873 global thread ID, which is the new equivalent of thread numbers in
2874 previous releases. See also $_gthread below.
2876 For backwards compatibility, MI's thread IDs always refer to global
2879 * Commands that accept thread IDs now accept the qualified
2880 INF_NUM.THR_NUM form as well. For example:
2883 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2886 * In commands that accept a list of thread IDs, you can now refer to
2887 all threads of an inferior using a star wildcard. GDB accepts
2888 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2889 refer to all threads of the current inferior. For example, "info
2892 * You can use "info threads -gid" to display the global thread ID of
2895 * The new convenience variable $_gthread holds the global number of
2898 * The new convenience variable $_inferior holds the number of the
2901 * GDB now displays the ID and name of the thread that hit a breakpoint
2902 or received a signal, if your program is multi-threaded. For
2905 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2906 Thread 1 "main" received signal SIGINT, Interrupt.
2908 * Record btrace now supports non-stop mode.
2910 * Support for tracepoints on aarch64-linux was added in GDBserver.
2912 * The 'record instruction-history' command now indicates speculative execution
2913 when using the Intel Processor Trace recording format.
2915 * GDB now allows users to specify explicit locations, bypassing
2916 the linespec parser. This feature is also available to GDB/MI
2919 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2920 GDB now is able to debug both AArch64 applications and ARM applications
2923 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2924 including JIT compiling fast tracepoint's conditional expression bytecode
2927 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2929 * "info threads", "info inferiors", "info display", "info checkpoints"
2930 and "maint info program-spaces" now list the corresponding items in
2931 ascending ID order, for consistency with all other "info" commands.
2933 * In Ada, the overloads selection menu has been enhanced to display the
2934 parameter types and the return types for the matching overloaded subprograms.
2938 maint set target-non-stop (on|off|auto)
2939 maint show target-non-stop
2940 Control whether GDB targets always operate in non-stop mode even if
2941 "set non-stop" is "off". The default is "auto", meaning non-stop
2942 mode is enabled if supported by the target.
2944 maint set bfd-sharing
2945 maint show bfd-sharing
2946 Control the reuse of bfd objects.
2949 show debug bfd-cache
2950 Control display of debugging info regarding bfd caching.
2954 Control display of debugging info regarding FreeBSD threads.
2956 set remote multiprocess-extensions-packet
2957 show remote multiprocess-extensions-packet
2958 Set/show the use of the remote protocol multiprocess extensions.
2960 set remote thread-events
2961 show remote thread-events
2962 Set/show the use of thread create/exit events.
2964 set ada print-signatures on|off
2965 show ada print-signatures"
2966 Control whether parameter types and return types are displayed in overloads
2967 selection menus. It is activated (@code{on}) by default.
2971 Controls the maximum size of memory, in bytes, that GDB will
2972 allocate for value contents. Prevents incorrect programs from
2973 causing GDB to allocate overly large buffers. Default is 64k.
2975 * The "disassemble" command accepts a new modifier: /s.
2976 It prints mixed source+disassembly like /m with two differences:
2977 - disassembled instructions are now printed in program order, and
2978 - and source for all relevant files is now printed.
2979 The "/m" option is now considered deprecated: its "source-centric"
2980 output hasn't proved useful in practice.
2982 * The "record instruction-history" command accepts a new modifier: /s.
2983 It behaves exactly like /m and prints mixed source+disassembly.
2985 * The "set scheduler-locking" command supports a new mode "replay".
2986 It behaves like "off" in record mode and like "on" in replay mode.
2988 * Support for various ROM monitors has been removed:
2990 target dbug dBUG ROM monitor for Motorola ColdFire
2991 target picobug Motorola picobug monitor
2992 target dink32 DINK32 ROM monitor for PowerPC
2993 target m32r Renesas M32R/D ROM monitor
2994 target mon2000 mon2000 ROM monitor
2995 target ppcbug PPCBUG ROM monitor for PowerPC
2997 * Support for reading/writing memory and extracting values on architectures
2998 whose memory is addressable in units of any integral multiple of 8 bits.
3001 Allows to break when an Ada exception is handled.
3003 * New remote packets
3006 Indicates that an exec system call was executed.
3008 exec-events feature in qSupported
3009 The qSupported packet allows GDB to request support for exec
3010 events using the new 'gdbfeature' exec-event, and the qSupported
3011 response can contain the corresponding 'stubfeature'. Set and
3012 show commands can be used to display whether these features are enabled.
3015 Equivalent to interrupting with the ^C character, but works in
3018 thread created stop reason (T05 create:...)
3019 Indicates that the thread was just created and is stopped at entry.
3021 thread exit stop reply (w exitcode;tid)
3022 Indicates that the thread has terminated.
3025 Enables/disables thread create and exit event reporting. For
3026 example, this is used in non-stop mode when GDB stops a set of
3027 threads and synchronously waits for the their corresponding stop
3028 replies. Without exit events, if one of the threads exits, GDB
3029 would hang forever not knowing that it should no longer expect a
3030 stop for that same thread.
3033 Indicates that there are no resumed threads left in the target (all
3034 threads are stopped). The remote stub reports support for this stop
3035 reply to GDB's qSupported query.
3038 Enables/disables catching syscalls from the inferior process.
3039 The remote stub reports support for this packet to GDB's qSupported query.
3041 syscall_entry stop reason
3042 Indicates that a syscall was just called.
3044 syscall_return stop reason
3045 Indicates that a syscall just returned.
3047 * Extended-remote exec events
3049 ** GDB now has support for exec events on extended-remote Linux targets.
3050 For such targets with Linux kernels 2.5.46 and later, this enables
3051 follow-exec-mode and exec catchpoints.
3053 set remote exec-event-feature-packet
3054 show remote exec-event-feature-packet
3055 Set/show the use of the remote exec event feature.
3057 * Thread names in remote protocol
3059 The reply to qXfer:threads:read may now include a name attribute for each
3062 * Target remote mode fork and exec events
3064 ** GDB now has support for fork and exec events on target remote mode
3065 Linux targets. For such targets with Linux kernels 2.5.46 and later,
3066 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
3067 fork and exec catchpoints.
3069 * Remote syscall events
3071 ** GDB now has support for catch syscall on remote Linux targets,
3072 currently enabled on x86/x86_64 architectures.
3074 set remote catch-syscall-packet
3075 show remote catch-syscall-packet
3076 Set/show the use of the remote catch syscall feature.
3080 ** The -var-set-format command now accepts the zero-hexadecimal
3081 format. It outputs data in hexadecimal format with zero-padding on the
3086 ** gdb.InferiorThread objects have a new attribute "global_num",
3087 which refers to the thread's global thread ID. The existing
3088 "num" attribute now refers to the thread's per-inferior number.
3089 See "Per-inferior thread numbers" above.
3090 ** gdb.InferiorThread objects have a new attribute "inferior", which
3091 is the Inferior object the thread belongs to.
3093 *** Changes in GDB 7.10
3095 * Support for process record-replay and reverse debugging on aarch64*-linux*
3096 targets has been added. GDB now supports recording of A64 instruction set
3097 including advance SIMD instructions.
3099 * Support for Sun's version of the "stabs" debug file format has been removed.
3101 * GDB now honors the content of the file /proc/PID/coredump_filter
3102 (PID is the process ID) on GNU/Linux systems. This file can be used
3103 to specify the types of memory mappings that will be included in a
3104 corefile. For more information, please refer to the manual page of
3105 "core(5)". GDB also has a new command: "set use-coredump-filter
3106 on|off". It allows to set whether GDB will read the content of the
3107 /proc/PID/coredump_filter file when generating a corefile.
3109 * The "info os" command on GNU/Linux can now display information on
3111 "info os cpus" Listing of all cpus/cores on the system
3113 * GDB has two new commands: "set serial parity odd|even|none" and
3114 "show serial parity". These allows to set or show parity for the
3117 * The "info source" command now displays the producer string if it was
3118 present in the debug info. This typically includes the compiler version
3119 and may include things like its command line arguments.
3121 * The "info dll", an alias of the "info sharedlibrary" command,
3122 is now available on all platforms.
3124 * Directory names supplied to the "set sysroot" commands may be
3125 prefixed with "target:" to tell GDB to access shared libraries from
3126 the target system, be it local or remote. This replaces the prefix
3127 "remote:". The default sysroot has been changed from "" to
3128 "target:". "remote:" is automatically converted to "target:" for
3129 backward compatibility.
3131 * The system root specified by "set sysroot" will be prepended to the
3132 filename of the main executable (if reported to GDB as absolute by
3133 the operating system) when starting processes remotely, and when
3134 attaching to already-running local or remote processes.
3136 * GDB now supports automatic location and retrieval of executable
3137 files from remote targets. Remote debugging can now be initiated
3138 using only a "target remote" or "target extended-remote" command
3139 (no "set sysroot" or "file" commands are required). See "New remote
3142 * The "dump" command now supports verilog hex format.
3144 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
3146 * On GNU/Linux, GDB and gdbserver are now able to access executable
3147 and shared library files without a "set sysroot" command when
3148 attaching to processes running in different mount namespaces from
3149 the debugger. This makes it possible to attach to processes in
3150 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
3151 See "New remote packets" below.
3153 * The "tui reg" command now provides completion for all of the
3154 available register groups, including target specific groups.
3156 * The HISTSIZE environment variable is no longer read when determining
3157 the size of GDB's command history. GDB now instead reads the dedicated
3158 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
3159 disables truncation of command history. Non-numeric values of GDBHISTSIZE
3164 ** Memory ports can now be unbuffered.
3168 ** gdb.Objfile objects have a new attribute "username",
3169 which is the name of the objfile as specified by the user,
3170 without, for example, resolving symlinks.
3171 ** You can now write frame unwinders in Python.
3172 ** gdb.Type objects have a new method "optimized_out",
3173 returning optimized out gdb.Value instance of this type.
3174 ** gdb.Value objects have new methods "reference_value" and
3175 "const_value" which return a reference to the value and a
3176 "const" version of the value respectively.
3180 maint print symbol-cache
3181 Print the contents of the symbol cache.
3183 maint print symbol-cache-statistics
3184 Print statistics of symbol cache usage.
3186 maint flush-symbol-cache
3187 Flush the contents of the symbol cache.
3191 Start branch trace recording using Branch Trace Store (BTS) format.
3194 Evaluate expression by using the compiler and print result.
3198 Explicit commands for enabling and disabling tui mode.
3201 set mpx bound on i386 and amd64
3202 Support for bound table investigation on Intel MPX enabled applications.
3206 Start branch trace recording using Intel Processor Trace format.
3209 Print information about branch tracing internals.
3211 maint btrace packet-history
3212 Print the raw branch tracing data.
3214 maint btrace clear-packet-history
3215 Discard the stored raw branch tracing data.
3218 Discard all branch tracing data. It will be fetched and processed
3219 anew by the next "record" command.
3224 Renamed from "set debug dwarf2-die".
3225 show debug dwarf-die
3226 Renamed from "show debug dwarf2-die".
3228 set debug dwarf-read
3229 Renamed from "set debug dwarf2-read".
3230 show debug dwarf-read
3231 Renamed from "show debug dwarf2-read".
3233 maint set dwarf always-disassemble
3234 Renamed from "maint set dwarf2 always-disassemble".
3235 maint show dwarf always-disassemble
3236 Renamed from "maint show dwarf2 always-disassemble".
3238 maint set dwarf max-cache-age
3239 Renamed from "maint set dwarf2 max-cache-age".
3240 maint show dwarf max-cache-age
3241 Renamed from "maint show dwarf2 max-cache-age".
3243 set debug dwarf-line
3244 show debug dwarf-line
3245 Control display of debugging info regarding DWARF line processing.
3248 show max-completions
3249 Set the maximum number of candidates to be considered during
3250 completion. The default value is 200. This limit allows GDB
3251 to avoid generating large completion lists, the computation of
3252 which can cause the debugger to become temporarily unresponsive.
3254 set history remove-duplicates
3255 show history remove-duplicates
3256 Control the removal of duplicate history entries.
3258 maint set symbol-cache-size
3259 maint show symbol-cache-size
3260 Control the size of the symbol cache.
3262 set|show record btrace bts buffer-size
3263 Set and show the size of the ring buffer used for branch tracing in
3265 The obtained size may differ from the requested size. Use "info
3266 record" to see the obtained buffer size.
3268 set debug linux-namespaces
3269 show debug linux-namespaces
3270 Control display of debugging info regarding Linux namespaces.
3272 set|show record btrace pt buffer-size
3273 Set and show the size of the ring buffer used for branch tracing in
3274 Intel Processor Trace format.
3275 The obtained size may differ from the requested size. Use "info
3276 record" to see the obtained buffer size.
3278 maint set|show btrace pt skip-pad
3279 Set and show whether PAD packets are skipped when computing the
3282 * The command 'thread apply all' can now support new option '-ascending'
3283 to call its specified command for all threads in ascending order.
3285 * Python/Guile scripting
3287 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3288 special section named `.debug_gdb_scripts'.
3290 * New remote packets
3292 qXfer:btrace-conf:read
3293 Return the branch trace configuration for the current thread.
3295 Qbtrace-conf:bts:size
3296 Set the requested ring buffer size for branch tracing in BTS format.
3299 Enable Intel Processor Trace-based branch tracing for the current
3300 process. The remote stub reports support for this packet to GDB's
3303 Qbtrace-conf:pt:size
3304 Set the requested ring buffer size for branch tracing in Intel Processor
3308 Indicates a memory breakpoint instruction was executed, irrespective
3309 of whether it was GDB that planted the breakpoint or the breakpoint
3310 is hardcoded in the program. This is required for correct non-stop
3314 Indicates the target stopped for a hardware breakpoint. This is
3315 required for correct non-stop mode operation.
3318 Return information about files on the remote system.
3320 qXfer:exec-file:read
3321 Return the full absolute name of the file that was executed to
3322 create a process running on the remote system.
3325 Select the filesystem on which vFile: operations with filename
3326 arguments will operate. This is required for GDB to be able to
3327 access files on remote targets where the remote stub does not
3328 share a common filesystem with the inferior(s).
3331 Indicates that a fork system call was executed.
3334 Indicates that a vfork system call was executed.
3336 vforkdone stop reason
3337 Indicates that a vfork child of the specified process has executed
3338 an exec or exit, allowing the vfork parent to resume execution.
3340 fork-events and vfork-events features in qSupported
3341 The qSupported packet allows GDB to request support for fork and
3342 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3343 and the qSupported response can contain the corresponding
3344 'stubfeatures'. Set and show commands can be used to display
3345 whether these features are enabled.
3347 * Extended-remote fork events
3349 ** GDB now has support for fork events on extended-remote Linux
3350 targets. For targets with Linux kernels 2.5.60 and later, this
3351 enables follow-fork-mode and detach-on-fork for both fork and
3352 vfork, as well as fork and vfork catchpoints.
3354 * The info record command now shows the recording format and the
3355 branch tracing configuration for the current thread when using
3356 the btrace record target.
3357 For the BTS format, it shows the ring buffer size.
3359 * GDB now has support for DTrace USDT (Userland Static Defined
3360 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3362 * GDB now supports access to vector registers on S/390 GNU/Linux
3365 * Removed command line options
3367 -xdb HP-UX XDB compatibility mode.
3369 * Removed targets and native configurations
3371 HP/PA running HP-UX hppa*-*-hpux*
3372 Itanium running HP-UX ia64-*-hpux*
3374 * New configure options
3377 This configure option allows the user to build GDB with support for
3378 Intel Processor Trace (default: auto). This requires libipt.
3380 --with-libipt-prefix=PATH
3381 Specify the path to the version of libipt that GDB should use.
3382 $PATH/include should contain the intel-pt.h header and
3383 $PATH/lib should contain the libipt.so library.
3385 *** Changes in GDB 7.9.1
3389 ** Xmethods can now specify a result type.
3391 *** Changes in GDB 7.9
3393 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3397 ** You can now access frame registers from Python scripts.
3398 ** New attribute 'producer' for gdb.Symtab objects.
3399 ** gdb.Objfile objects have a new attribute "progspace",
3400 which is the gdb.Progspace object of the containing program space.
3401 ** gdb.Objfile objects have a new attribute "owner".
3402 ** gdb.Objfile objects have a new attribute "build_id",
3403 which is the build ID generated when the file was built.
3404 ** gdb.Objfile objects have a new method "add_separate_debug_file".
3405 ** A new event "gdb.clear_objfiles" has been added, triggered when
3406 selecting a new file to debug.
3407 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3408 ** New function gdb.lookup_objfile.
3410 New events which are triggered when GDB modifies the state of the
3413 ** gdb.events.inferior_call_pre: Function call is about to be made.
3414 ** gdb.events.inferior_call_post: Function call has just been made.
3415 ** gdb.events.memory_changed: A memory location has been altered.
3416 ** gdb.events.register_changed: A register has been altered.
3418 * New Python-based convenience functions:
3420 ** $_caller_is(name [, number_of_frames])
3421 ** $_caller_matches(regexp [, number_of_frames])
3422 ** $_any_caller_is(name [, number_of_frames])
3423 ** $_any_caller_matches(regexp [, number_of_frames])
3425 * GDB now supports the compilation and injection of source code into
3426 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
3427 to compile the source code to object code, and if successful, inject
3428 and execute that code within the current context of the inferior.
3429 Currently the C language is supported. The commands used to
3430 interface with this new feature are:
3432 compile code [-raw|-r] [--] [source code]
3433 compile file [-raw|-r] filename
3437 demangle [-l language] [--] name
3438 Demangle "name" in the specified language, or the current language
3439 if elided. This command is renamed from the "maint demangle" command.
3440 The latter is kept as a no-op to avoid "maint demangle" being interpreted
3441 as "maint demangler-warning".
3443 queue-signal signal-name-or-number
3444 Queue a signal to be delivered to the thread when it is resumed.
3446 add-auto-load-scripts-directory directory
3447 Add entries to the list of directories from which to load auto-loaded
3450 maint print user-registers
3451 List all currently available "user" registers.
3453 compile code [-r|-raw] [--] [source code]
3454 Compile, inject, and execute in the inferior the executable object
3455 code produced by compiling the provided source code.
3457 compile file [-r|-raw] filename
3458 Compile and inject into the inferior the executable object code
3459 produced by compiling the source code stored in the filename
3462 * On resume, GDB now always passes the signal the program had stopped
3463 for to the thread the signal was sent to, even if the user changed
3464 threads before resuming. Previously GDB would often (but not
3465 always) deliver the signal to the thread that happens to be current
3468 * Conversely, the "signal" command now consistently delivers the
3469 requested signal to the current thread. GDB now asks for
3470 confirmation if the program had stopped for a signal and the user
3471 switched threads meanwhile.
3473 * "breakpoint always-inserted" modes "off" and "auto" merged.
3475 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3476 won't remove breakpoints from the target until all threads stop,
3477 even in non-stop mode. The "auto" mode has been removed, and "off"
3478 is now the default mode.
3482 set debug symbol-lookup
3483 show debug symbol-lookup
3484 Control display of debugging info regarding symbol lookup.
3488 ** The -list-thread-groups command outputs an exit-code field for
3489 inferiors that have exited.
3493 MIPS SDE mips*-sde*-elf*
3497 Support for these obsolete configurations has been removed.
3499 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
3500 SGI Irix-5.x mips-*-irix5*
3501 SGI Irix-6.x mips-*-irix6*
3502 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
3503 VAX running Ultrix vax-*-ultrix*
3505 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3506 and "assf"), have been removed. Use the "sharedlibrary" command, or
3507 its alias "share", instead.
3509 *** Changes in GDB 7.8
3511 * New command line options
3514 This is an alias for the --data-directory option.
3516 * GDB supports printing and modifying of variable length automatic arrays
3517 as specified in ISO C99.
3519 * The ARM simulator now supports instruction level tracing
3520 with or without disassembly.
3524 GDB now has support for scripting using Guile. Whether this is
3525 available is determined at configure time.
3526 Guile version 2.0 or greater is required.
3527 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3529 * New commands (for set/show, see "New options" below)
3533 Invoke CODE by passing it to the Guile interpreter.
3537 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3539 info auto-load guile-scripts [regexp]
3540 Print the list of automatically loaded Guile scripts.
3542 * The source command is now capable of sourcing Guile scripts.
3543 This feature is dependent on the debugger being built with Guile support.
3547 set print symbol-loading (off|brief|full)
3548 show print symbol-loading
3549 Control whether to print informational messages when loading symbol
3550 information for a file. The default is "full", but when debugging
3551 programs with large numbers of shared libraries the amount of output
3552 becomes less useful.
3554 set guile print-stack (none|message|full)
3555 show guile print-stack
3556 Show a stack trace when an error is encountered in a Guile script.
3558 set auto-load guile-scripts (on|off)
3559 show auto-load guile-scripts
3560 Control auto-loading of Guile script files.
3562 maint ada set ignore-descriptive-types (on|off)
3563 maint ada show ignore-descriptive-types
3564 Control whether the debugger should ignore descriptive types in Ada
3565 programs. The default is not to ignore the descriptive types. See
3566 the user manual for more details on descriptive types and the intended
3567 usage of this option.
3569 set auto-connect-native-target
3571 Control whether GDB is allowed to automatically connect to the
3572 native target for the run, attach, etc. commands when not connected
3573 to any target yet. See also "target native" below.
3575 set record btrace replay-memory-access (read-only|read-write)
3576 show record btrace replay-memory-access
3577 Control what memory accesses are allowed during replay.
3579 maint set target-async (on|off)
3580 maint show target-async
3581 This controls whether GDB targets operate in synchronous or
3582 asynchronous mode. Normally the default is asynchronous, if it is
3583 available; but this can be changed to more easily debug problems
3584 occurring only in synchronous mode.
3586 set mi-async (on|off)
3588 Control whether MI asynchronous mode is preferred. This supersedes
3589 "set target-async" of previous GDB versions.
3591 * "set target-async" is deprecated as a CLI option and is now an alias
3592 for "set mi-async" (only puts MI into async mode).
3594 * Background execution commands (e.g., "c&", "s&", etc.) are now
3595 possible ``out of the box'' if the target supports them. Previously
3596 the user would need to explicitly enable the possibility with the
3597 "set target-async on" command.
3599 * New features in the GDB remote stub, GDBserver
3601 ** New option --debug-format=option1[,option2,...] allows one to add
3602 additional text to each output. At present only timestamps
3603 are supported: --debug-format=timestamps.
3604 Timestamps can also be turned on with the
3605 "monitor set debug-format timestamps" command from GDB.
3607 * The 'record instruction-history' command now starts counting instructions
3608 at one. This also affects the instruction ranges reported by the
3609 'record function-call-history' command when given the /i modifier.
3611 * The command 'record function-call-history' supports a new modifier '/c' to
3612 indent the function names based on their call stack depth.
3613 The fields for the '/i' and '/l' modifier have been reordered.
3614 The source line range is now prefixed with 'at'.
3615 The instruction range is now prefixed with 'inst'.
3616 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3617 "record instruction-history" and "list" commands.
3619 * The ranges given as arguments to the 'record function-call-history' and
3620 'record instruction-history' commands are now inclusive.
3622 * The btrace record target now supports the 'record goto' command.
3623 For locations inside the execution trace, the back trace is computed
3624 based on the information stored in the execution trace.
3626 * The btrace record target supports limited reverse execution and replay.
3627 The target does not record data and therefore does not allow reading
3628 memory or registers.
3630 * The "catch syscall" command now works on s390*-linux* targets.
3632 * The "compare-sections" command is no longer specific to target
3633 remote. It now works with all targets.
3635 * All native targets are now consistently called "native".
3636 Consequently, the "target child", "target GNU", "target djgpp",
3637 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3638 commands have been replaced with "target native". The QNX/NTO port
3639 leaves the "procfs" target in place and adds a "native" target for
3640 consistency with other ports. The impact on users should be minimal
3641 as these commands previously either throwed an error, or were
3642 no-ops. The target's name is visible in the output of the following
3643 commands: "help target", "info target", "info files", "maint print
3646 * The "target native" command now connects to the native target. This
3647 can be used to launch native programs even when "set
3648 auto-connect-native-target" is set to off.
3650 * GDB now supports access to Intel MPX registers on GNU/Linux.
3652 * Support for Intel AVX-512 registers on GNU/Linux.
3653 Support displaying and modifying Intel AVX-512 registers
3654 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3656 * New remote packets
3658 qXfer:btrace:read's annex
3659 The qXfer:btrace:read packet supports a new annex 'delta' to read
3660 branch trace incrementally.
3664 ** Valid Python operations on gdb.Value objects representing
3665 structs/classes invoke the corresponding overloaded operators if
3667 ** New `Xmethods' feature in the Python API. Xmethods are
3668 additional methods or replacements for existing methods of a C++
3669 class. This feature is useful for those cases where a method
3670 defined in C++ source code could be inlined or optimized out by
3671 the compiler, making it unavailable to GDB.
3674 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3676 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3677 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3678 its alias "share", instead.
3680 * The commands "set remotebaud" and "show remotebaud" are no longer
3681 supported. Use "set serial baud" and "show serial baud" (respectively)
3686 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3687 target-async". The latter is left as a deprecated alias of the
3688 former for backward compatibility. If the target supports it,
3689 CLI background execution commands are now always possible by
3690 default, independently of whether the frontend stated a
3691 preference for asynchronous execution with "-gdb-set mi-async".
3692 Previously "-gdb-set target-async off" affected both MI execution
3693 commands and CLI execution commands.
3695 *** Changes in GDB 7.7
3697 * Improved support for process record-replay and reverse debugging on
3698 arm*-linux* targets. Support for thumb32 and syscall instruction
3699 recording has been added.
3701 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3703 * GDB now supports Fission DWP file format version 2.
3704 http://gcc.gnu.org/wiki/DebugFission
3706 * New convenience function "$_isvoid", to check whether an expression
3707 is void. A void expression is an expression where the type of the
3708 result is "void". For example, some convenience variables may be
3709 "void" when evaluated (e.g., "$_exitcode" before the execution of
3710 the program being debugged; or an undefined convenience variable).
3711 Another example, when calling a function whose return type is
3714 * The "maintenance print objfiles" command now takes an optional regexp.
3716 * The "catch syscall" command now works on arm*-linux* targets.
3718 * GDB now consistently shows "<not saved>" when printing values of
3719 registers the debug info indicates have not been saved in the frame
3720 and there's nowhere to retrieve them from
3721 (callee-saved/call-clobbered registers):
3726 (gdb) info registers rax
3729 Before, the former would print "<optimized out>", and the latter
3730 "*value not available*".
3732 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3737 ** Frame filters and frame decorators have been added.
3738 ** Temporary breakpoints are now supported.
3739 ** Line tables representation has been added.
3740 ** New attribute 'parent_type' for gdb.Field objects.
3741 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3742 ** New attribute 'name' for gdb.Type objects.
3746 Nios II ELF nios2*-*-elf
3747 Nios II GNU/Linux nios2*-*-linux
3748 Texas Instruments MSP430 msp430*-*-elf
3750 * Removed native configurations
3752 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3753 been removed. ELF variants of these configurations are kept supported.
3755 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3756 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3757 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3758 i[34567]86-*-openbsd3.[0-3]
3759 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3760 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3761 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3765 Like "catch throw", but catches a re-thrown exception.
3766 maint check-psymtabs
3767 Renamed from old "maint check-symtabs".
3769 Perform consistency checks on symtabs.
3770 maint expand-symtabs
3771 Expand symtabs matching an optional regexp.
3774 Display the details of GDB configure-time options.
3776 maint set|show per-command
3777 maint set|show per-command space
3778 maint set|show per-command time
3779 maint set|show per-command symtab
3780 Enable display of per-command gdb resource usage.
3782 remove-symbol-file FILENAME
3783 remove-symbol-file -a ADDRESS
3784 Remove a symbol file added via add-symbol-file. The file to remove
3785 can be identified by its filename or by an address that lies within
3786 the boundaries of this symbol file in memory.
3789 info exceptions REGEXP
3790 Display the list of Ada exceptions defined in the program being
3791 debugged. If provided, only the exceptions whose names match REGEXP
3796 set debug symfile off|on
3798 Control display of debugging info regarding reading symbol files and
3799 symbol tables within those files
3801 set print raw frame-arguments
3802 show print raw frame-arguments
3803 Set/show whether to print frame arguments in raw mode,
3804 disregarding any defined pretty-printers.
3806 set remote trace-status-packet
3807 show remote trace-status-packet
3808 Set/show the use of remote protocol qTStatus packet.
3812 Control display of debugging messages related to Nios II targets.
3816 Control whether target-assisted range stepping is enabled.
3818 set startup-with-shell
3819 show startup-with-shell
3820 Specifies whether Unix child processes are started via a shell or
3825 Use the target memory cache for accesses to the code segment. This
3826 improves performance of remote debugging (particularly disassembly).
3828 * You can now use a literal value 'unlimited' for options that
3829 interpret 0 or -1 as meaning "unlimited". E.g., "set
3830 trace-buffer-size unlimited" is now an alias for "set
3831 trace-buffer-size -1" and "set height unlimited" is now an alias for
3834 * The "set debug symtab-create" debugging option of GDB has been changed to
3835 accept a verbosity level. 0 means "off", 1 provides basic debugging
3836 output, and values of 2 or greater provides more verbose output.
3838 * New command-line options
3840 Display the details of GDB configure-time options.
3842 * The command 'tsave' can now support new option '-ctf' to save trace
3843 buffer in Common Trace Format.
3845 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3848 * GDB now implements the C++ 'typeid' operator.
3850 * The new convenience variable $_exception holds the exception being
3851 thrown or caught at an exception-related catchpoint.
3853 * The exception-related catchpoints, like "catch throw", now accept a
3854 regular expression which can be used to filter exceptions by type.
3856 * The new convenience variable $_exitsignal is automatically set to
3857 the terminating signal number when the program being debugged dies
3858 due to an uncaught signal.
3862 ** All MI commands now accept an optional "--language" option.
3863 Support for this feature can be verified by using the "-list-features"
3864 command, which should contain "language-option".
3866 ** The new command -info-gdb-mi-command allows the user to determine
3867 whether a GDB/MI command is supported or not.
3869 ** The "^error" result record returned when trying to execute an undefined
3870 GDB/MI command now provides a variable named "code" whose content is the
3871 "undefined-command" error code. Support for this feature can be verified
3872 by using the "-list-features" command, which should contain
3873 "undefined-command-error-code".
3875 ** The -trace-save MI command can optionally save trace buffer in Common
3878 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3880 ** The command -data-list-register-values now accepts an optional
3881 "--skip-unavailable" option. When used, only the available registers
3884 ** The new command -trace-frame-collected dumps collected variables,
3885 computed expressions, tvars, memory and registers in a traceframe.
3887 ** The commands -stack-list-locals, -stack-list-arguments and
3888 -stack-list-variables now accept an option "--skip-unavailable".
3889 When used, only the available locals or arguments are displayed.
3891 ** The -exec-run command now accepts an optional "--start" option.
3892 When used, the command follows the same semantics as the "start"
3893 command, stopping the program's execution at the start of its
3894 main subprogram. Support for this feature can be verified using
3895 the "-list-features" command, which should contain
3896 "exec-run-start-option".
3898 ** The new commands -catch-assert and -catch-exceptions insert
3899 catchpoints stopping the program when Ada exceptions are raised.
3901 ** The new command -info-ada-exceptions provides the equivalent of
3902 the new "info exceptions" command.
3904 * New system-wide configuration scripts
3905 A GDB installation now provides scripts suitable for use as system-wide
3906 configuration scripts for the following systems:
3910 * GDB now supports target-assigned range stepping with remote targets.
3911 This improves the performance of stepping source lines by reducing
3912 the number of control packets from/to GDB. See "New remote packets"
3915 * GDB now understands the element 'tvar' in the XML traceframe info.
3916 It has the id of the collected trace state variables.
3918 * On S/390 targets that provide the transactional-execution feature,
3919 the program interruption transaction diagnostic block (TDB) is now
3920 represented as a number of additional "registers" in GDB.
3922 * New remote packets
3926 The vCont packet supports a new 'r' action, that tells the remote
3927 stub to step through an address range itself, without GDB
3928 involvemement at each single-step.
3930 qXfer:libraries-svr4:read's annex
3931 The previously unused annex of the qXfer:libraries-svr4:read packet
3932 is now used to support passing an argument list. The remote stub
3933 reports support for this argument list to GDB's qSupported query.
3934 The defined arguments are "start" and "prev", used to reduce work
3935 necessary for library list updating, resulting in significant
3938 * New features in the GDB remote stub, GDBserver
3940 ** GDBserver now supports target-assisted range stepping. Currently
3941 enabled on x86/x86_64 GNU/Linux targets.
3943 ** GDBserver now adds element 'tvar' in the XML in the reply to
3944 'qXfer:traceframe-info:read'. It has the id of the collected
3945 trace state variables.
3947 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3950 * New 'z' formatter for printing and examining memory, this displays the
3951 value as hexadecimal zero padded on the left to the size of the type.
3953 * GDB can now use Windows x64 unwinding data.
3955 * The "set remotebaud" command has been replaced by "set serial baud".
3956 Similarly, "show remotebaud" has been replaced by "show serial baud".
3957 The "set remotebaud" and "show remotebaud" commands are still available
3958 to provide backward compatibility with older versions of GDB.
3960 *** Changes in GDB 7.6
3962 * Target record has been renamed to record-full.
3963 Record/replay is now enabled with the "record full" command.
3964 This also affects settings that are associated with full record/replay
3965 that have been moved from "set/show record" to "set/show record full":
3967 set|show record full insn-number-max
3968 set|show record full stop-at-limit
3969 set|show record full memory-query
3971 * A new record target "record-btrace" has been added. The new target
3972 uses hardware support to record the control-flow of a process. It
3973 does not support replaying the execution, but it implements the
3974 below new commands for investigating the recorded execution log.
3975 This new recording method can be enabled using:
3979 The "record-btrace" target is only available on Intel Atom processors
3980 and requires a Linux kernel 2.6.32 or later.
3982 * Two new commands have been added for record/replay to give information
3983 about the recorded execution without having to replay the execution.
3984 The commands are only supported by "record btrace".
3986 record instruction-history prints the execution history at
3987 instruction granularity
3989 record function-call-history prints the execution history at
3990 function granularity
3992 * New native configurations
3994 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3995 FreeBSD/powerpc powerpc*-*-freebsd
3996 x86_64/Cygwin x86_64-*-cygwin*
3997 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
4001 ARM AArch64 aarch64*-*-elf
4002 ARM AArch64 GNU/Linux aarch64*-*-linux
4003 Lynx 178 PowerPC powerpc-*-lynx*178
4004 x86_64/Cygwin x86_64-*-cygwin*
4005 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
4007 * If the configured location of system.gdbinit file (as given by the
4008 --with-system-gdbinit option at configure time) is in the
4009 data-directory (as specified by --with-gdb-datadir at configure
4010 time) or in one of its subdirectories, then GDB will look for the
4011 system-wide init file in the directory specified by the
4012 --data-directory command-line option.
4014 * New command line options:
4016 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
4017 other initialization files, unlike -nx which disables all of them.
4019 * Removed command line options
4021 -epoch This was used by the gdb mode in Epoch, an ancient fork of
4024 * The 'ptype' and 'whatis' commands now accept an argument to control
4027 * 'info proc' now works on some core files.
4031 ** Vectors can be created with gdb.Type.vector.
4033 ** Python's atexit.register now works in GDB.
4035 ** Types can be pretty-printed via a Python API.
4037 ** Python 3 is now supported (in addition to Python 2.4 or later)
4039 ** New class gdb.Architecture exposes GDB's internal representation
4040 of architecture in the Python API.
4042 ** New method Frame.architecture returns the gdb.Architecture object
4043 corresponding to the frame's architecture.
4045 * New Python-based convenience functions:
4047 ** $_memeq(buf1, buf2, length)
4048 ** $_streq(str1, str2)
4050 ** $_regex(str, regex)
4052 * The 'cd' command now defaults to using '~' (the home directory) if not
4055 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
4056 default for GCC since November 2000.
4058 * The command 'forward-search' can now be abbreviated as 'fo'.
4060 * The command 'info tracepoints' can now display 'installed on target'
4061 or 'not installed on target' for each non-pending location of tracepoint.
4063 * New configure options
4065 --enable-libmcheck/--disable-libmcheck
4066 By default, development versions are built with -lmcheck on hosts
4067 that support it, in order to help track memory corruption issues.
4068 Release versions, on the other hand, are built without -lmcheck
4069 by default. The --enable-libmcheck/--disable-libmcheck configure
4070 options allow the user to override that default.
4071 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
4072 This configure option allows the user to build GDB with
4073 libbabeltrace using which GDB can read Common Trace Format data.
4075 * New commands (for set/show, see "New options" below)
4078 Catch signals. This is similar to "handle", but allows commands and
4079 conditions to be attached.
4082 List the BFDs known to GDB.
4084 python-interactive [command]
4086 Start a Python interactive prompt, or evaluate the optional command
4087 and print the result of expressions.
4090 "py" is a new alias for "python".
4092 enable type-printer [name]...
4093 disable type-printer [name]...
4094 Enable or disable type printers.
4098 ** For the Renesas Super-H architecture, the "regs" command has been removed
4099 (has been deprecated in GDB 7.5), and "info all-registers" should be used
4104 set print type methods (on|off)
4105 show print type methods
4106 Control whether method declarations are displayed by "ptype".
4107 The default is to show them.
4109 set print type typedefs (on|off)
4110 show print type typedefs
4111 Control whether typedef definitions are displayed by "ptype".
4112 The default is to show them.
4114 set filename-display basename|relative|absolute
4115 show filename-display
4116 Control the way in which filenames is displayed.
4117 The default is "relative", which preserves previous behavior.
4119 set trace-buffer-size
4120 show trace-buffer-size
4121 Request target to change the size of trace buffer.
4123 set remote trace-buffer-size-packet auto|on|off
4124 show remote trace-buffer-size-packet
4125 Control the use of the remote protocol `QTBuffer:size' packet.
4129 Control display of debugging messages related to ARM AArch64.
4132 set debug coff-pe-read
4133 show debug coff-pe-read
4134 Control display of debugging messages related to reading of COFF/PE
4139 Control display of debugging messages related to Mach-O symbols
4142 set debug notification
4143 show debug notification
4144 Control display of debugging info for async remote notification.
4148 ** Command parameter changes are now notified using new async record
4149 "=cmd-param-changed".
4150 ** Trace frame changes caused by command "tfind" are now notified using
4151 new async record "=traceframe-changed".
4152 ** The creation, deletion and modification of trace state variables
4153 are now notified using new async records "=tsv-created",
4154 "=tsv-deleted" and "=tsv-modified".
4155 ** The start and stop of process record are now notified using new
4156 async record "=record-started" and "=record-stopped".
4157 ** Memory changes are now notified using new async record
4159 ** The data-disassemble command response will include a "fullname" field
4160 containing the absolute file name when source has been requested.
4161 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
4162 command, to allow pattern filling of memory areas.
4163 ** New commands "-catch-load"/"-catch-unload" added for intercepting
4164 library load/unload events.
4165 ** The response to breakpoint commands and breakpoint async records
4166 includes an "installed" field containing a boolean state about each
4167 non-pending tracepoint location is whether installed on target or not.
4168 ** Output of the "-trace-status" command includes a "trace-file" field
4169 containing the name of the trace file being examined. This field is
4170 optional, and only present when examining a trace file.
4171 ** The "fullname" field is now always present along with the "file" field,
4172 even if the file cannot be found by GDB.
4174 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4175 You must have the LZMA library available when configuring GDB for this
4176 feature to be enabled. For more information, see:
4177 http://fedoraproject.org/wiki/Features/MiniDebugInfo
4179 * New remote packets
4182 Set the size of trace buffer. The remote stub reports support for this
4183 packet to gdb's qSupported query.
4186 Enable Branch Trace Store (BTS)-based branch tracing for the current
4187 thread. The remote stub reports support for this packet to gdb's
4191 Disable branch tracing for the current thread. The remote stub reports
4192 support for this packet to gdb's qSupported query.
4195 Read the traced branches for the current thread. The remote stub
4196 reports support for this packet to gdb's qSupported query.
4198 *** Changes in GDB 7.5
4200 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
4201 for more x32 ABI info.
4203 * GDB now supports access to MIPS DSP registers on Linux targets.
4205 * GDB now supports debugging microMIPS binaries.
4207 * The "info os" command on GNU/Linux can now display information on
4208 several new classes of objects managed by the operating system:
4209 "info os procgroups" lists process groups
4210 "info os files" lists file descriptors
4211 "info os sockets" lists internet-domain sockets
4212 "info os shm" lists shared-memory regions
4213 "info os semaphores" lists semaphores
4214 "info os msg" lists message queues
4215 "info os modules" lists loaded kernel modules
4217 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
4218 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
4219 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4220 options and inspect the probe arguments using the new $_probe_arg family
4221 of convenience variables. You can obtain more information about SystemTap
4222 in <http://sourceware.org/systemtap/>.
4224 * GDB now supports reversible debugging on ARM, it allows you to
4225 debug basic ARM and THUMB instructions, and provides
4226 record/replay support.
4228 * The option "symbol-reloading" has been deleted as it is no longer used.
4232 ** GDB commands implemented in Python can now be put in command class
4235 ** The "maint set python print-stack on|off" is now deleted.
4237 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4238 apply "flag enum"-style pretty-printing to any enum.
4240 ** gdb.lookup_symbol can now work when there is no current frame.
4242 ** gdb.Symbol now has a 'line' attribute, holding the line number in
4243 the source at which the symbol was defined.
4245 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4246 method 'value'. The former indicates whether the symbol needs a
4247 frame in order to compute its value, and the latter computes the
4250 ** A new method 'referenced_value' on gdb.Value objects which can
4251 dereference pointer as well as C++ reference values.
4253 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4254 which return the global and static blocks (as gdb.Block objects),
4255 of the underlying symbol table, respectively.
4257 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4258 object associated with a PC value.
4260 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4261 of the address range occupied by code for the current source line.
4263 * Go language support.
4264 GDB now supports debugging programs written in the Go programming
4267 * GDBserver now supports stdio connections.
4268 E.g. (gdb) target remote | ssh myhost gdbserver - hello
4270 * The binary "gdbtui" can no longer be built or installed.
4271 Use "gdb -tui" instead.
4273 * GDB will now print "flag" enums specially. A flag enum is one where
4274 all the enumerator values have no bits in common when pairwise
4275 "and"ed. When printing a value whose type is a flag enum, GDB will
4276 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4277 (gdb) print (enum E) 3
4280 * The filename part of a linespec will now match trailing components
4281 of a source file name. For example, "break gcc/expr.c:1000" will
4282 now set a breakpoint in build/gcc/expr.c, but not
4283 build/libcpp/expr.c.
4285 * The "info proc" and "generate-core-file" commands will now also
4286 work on remote targets connected to GDBserver on Linux.
4288 * The command "info catch" has been removed. It has been disabled
4289 since December 2007.
4291 * The "catch exception" and "catch assert" commands now accept
4292 a condition at the end of the command, much like the "break"
4293 command does. For instance:
4295 (gdb) catch exception Constraint_Error if Barrier = True
4297 Previously, it was possible to add a condition to such catchpoints,
4298 but it had to be done as a second step, after the catchpoint had been
4299 created, using the "condition" command.
4301 * The "info static-tracepoint-marker" command will now also work on
4302 native Linux targets with in-process agent.
4304 * GDB can now set breakpoints on inlined functions.
4306 * The .gdb_index section has been updated to include symbols for
4307 inlined functions. GDB will ignore older .gdb_index sections by
4308 default, which could cause symbol files to be loaded more slowly
4309 until their .gdb_index sections can be recreated. The new command
4310 "set use-deprecated-index-sections on" will cause GDB to use any older
4311 .gdb_index sections it finds. This will restore performance, but the
4312 ability to set breakpoints on inlined functions will be lost in symbol
4313 files with older .gdb_index sections.
4315 The .gdb_index section has also been updated to record more information
4316 about each symbol. This speeds up the "info variables", "info functions"
4317 and "info types" commands when used with programs having the .gdb_index
4318 section, as well as speeding up debugging with shared libraries using
4319 the .gdb_index section.
4321 * Ada support for GDB/MI Variable Objects has been added.
4323 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4328 ** New command -info-os is the MI equivalent of "info os".
4330 ** Output logs ("set logging" and related) now include MI output.
4334 ** "set use-deprecated-index-sections on|off"
4335 "show use-deprecated-index-sections on|off"
4336 Controls the use of deprecated .gdb_index sections.
4338 ** "catch load" and "catch unload" can be used to stop when a shared
4339 library is loaded or unloaded, respectively.
4341 ** "enable count" can be used to auto-disable a breakpoint after
4344 ** "info vtbl" can be used to show the virtual method tables for
4345 C++ and Java objects.
4347 ** "explore" and its sub commands "explore value" and "explore type"
4348 can be used to recursively explore values and types of
4349 expressions. These commands are available only if GDB is
4350 configured with '--with-python'.
4352 ** "info auto-load" shows status of all kinds of auto-loaded files,
4353 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4354 sequences of commands files, "info auto-load python-scripts"
4355 shows status of auto-loading Python script files,
4356 "info auto-load local-gdbinit" shows status of loading init file
4357 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4358 status of inferior specific thread debugging shared library loading.
4360 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4361 and "show auto-load-scripts" commands have been deprecated, use their
4362 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4363 and "show auto-load python-scripts" counterparts instead.
4365 ** "dprintf location,format,args..." creates a dynamic printf, which
4366 is basically a breakpoint that does a printf and immediately
4367 resumes your program's execution, so it is like a printf that you
4368 can insert dynamically at runtime instead of at compiletime.
4370 ** "set print symbol"
4372 Controls whether GDB attempts to display the symbol, if any,
4373 corresponding to addresses it prints. This defaults to "on", but
4374 you can set it to "off" to restore GDB's previous behavior.
4376 * Deprecated commands
4378 ** For the Renesas Super-H architecture, the "regs" command has been
4379 deprecated, and "info all-registers" should be used instead.
4383 Renesas RL78 rl78-*-elf
4384 HP OpenVMS ia64 ia64-hp-openvms*
4386 * GDBserver supports evaluation of breakpoint conditions. When
4387 support is advertised by GDBserver, GDB may be told to send the
4388 breakpoint conditions in bytecode form to GDBserver. GDBserver
4389 will only report the breakpoint trigger to GDB when its condition
4394 set mips compression
4395 show mips compression
4396 Select the compressed ISA encoding used in functions that have no symbol
4397 information available. The encoding can be set to either of:
4400 and is updated automatically from ELF file flags if available.
4402 set breakpoint condition-evaluation
4403 show breakpoint condition-evaluation
4404 Control whether breakpoint conditions are evaluated by GDB ("host") or by
4405 GDBserver ("target"). Default option "auto" chooses the most efficient
4407 This option can improve debugger efficiency depending on the speed of the
4411 Disable auto-loading globally.
4414 Show auto-loading setting of all kinds of auto-loaded files.
4416 set auto-load gdb-scripts on|off
4417 show auto-load gdb-scripts
4418 Control auto-loading of GDB canned sequences of commands files.
4420 set auto-load python-scripts on|off
4421 show auto-load python-scripts
4422 Control auto-loading of Python script files.
4424 set auto-load local-gdbinit on|off
4425 show auto-load local-gdbinit
4426 Control loading of init file (.gdbinit) from current directory.
4428 set auto-load libthread-db on|off
4429 show auto-load libthread-db
4430 Control auto-loading of inferior specific thread debugging shared library.
4432 set auto-load scripts-directory <dir1>[:<dir2>...]
4433 show auto-load scripts-directory
4434 Set a list of directories from which to load auto-loaded scripts.
4435 Automatically loaded Python scripts and GDB scripts are located in one
4436 of the directories listed by this option.
4437 The delimiter (':' above) may differ according to the host platform.
4439 set auto-load safe-path <dir1>[:<dir2>...]
4440 show auto-load safe-path
4441 Set a list of directories from which it is safe to auto-load files.
4442 The delimiter (':' above) may differ according to the host platform.
4444 set debug auto-load on|off
4445 show debug auto-load
4446 Control display of debugging info for auto-loading the files above.
4448 set dprintf-style gdb|call|agent
4450 Control the way in which a dynamic printf is performed; "gdb"
4451 requests a GDB printf command, while "call" causes dprintf to call a
4452 function in the inferior. "agent" requests that the target agent
4453 (such as GDBserver) do the printing.
4455 set dprintf-function <expr>
4456 show dprintf-function
4457 set dprintf-channel <expr>
4458 show dprintf-channel
4459 Set the function and optional first argument to the call when using
4460 the "call" style of dynamic printf.
4462 set disconnected-dprintf on|off
4463 show disconnected-dprintf
4464 Control whether agent-style dynamic printfs continue to be in effect
4465 after GDB disconnects.
4467 * New configure options
4469 --with-auto-load-dir
4470 Configure default value for the 'set auto-load scripts-directory'
4471 setting above. It defaults to '$debugdir:$datadir/auto-load',
4472 $debugdir representing global debugging info directories (available
4473 via 'show debug-file-directory') and $datadir representing GDB's data
4474 directory (available via 'show data-directory').
4476 --with-auto-load-safe-path
4477 Configure default value for the 'set auto-load safe-path' setting
4478 above. It defaults to the --with-auto-load-dir setting.
4480 --without-auto-load-safe-path
4481 Set 'set auto-load safe-path' to '/', effectively disabling this
4484 * New remote packets
4486 z0/z1 conditional breakpoints extension
4488 The z0/z1 breakpoint insertion packets have been extended to carry
4489 a list of conditional expressions over to the remote stub depending on the
4490 condition evaluation mode. The use of this extension can be controlled
4491 via the "set remote conditional-breakpoints-packet" command.
4495 Specify the signals which the remote stub may pass to the debugged
4496 program without GDB involvement.
4498 * New command line options
4500 --init-command=FILE, -ix Like --command, -x but execute it
4501 before loading inferior.
4502 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4503 execute it before loading inferior.
4505 *** Changes in GDB 7.4
4507 * GDB now handles ambiguous linespecs more consistently; the existing
4508 FILE:LINE support has been expanded to other types of linespecs. A
4509 breakpoint will now be set on all matching locations in all
4510 inferiors, and locations will be added or removed according to
4513 * GDB now allows you to skip uninteresting functions and files when
4514 stepping with the "skip function" and "skip file" commands.
4516 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4517 and "show remote hardware-watchpoint-length-limit". These allows to
4518 set or show the maximum length limit (in bytes) of a remote
4519 target hardware watchpoint.
4521 This allows e.g. to use "unlimited" hardware watchpoints with the
4522 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
4523 watchpoints are slower than real hardware watchpoints but are
4524 significantly faster than gdb software watchpoints.
4528 ** The register_pretty_printer function in module gdb.printing now takes
4529 an optional `replace' argument. If True, the new printer replaces any
4532 ** The "maint set python print-stack on|off" command has been
4533 deprecated and will be deleted in GDB 7.5.
4534 A new command: "set python print-stack none|full|message" has
4535 replaced it. Additionally, the default for "print-stack" is
4536 now "message", which just prints the error message without
4539 ** A prompt substitution hook (prompt_hook) is now available to the
4542 ** A new Python module, gdb.prompt has been added to the GDB Python
4543 modules library. This module provides functionality for
4544 escape sequences in prompts (used by set/show
4545 extended-prompt). These escape sequences are replaced by their
4546 corresponding value.
4548 ** Python commands and convenience-functions located in
4549 'data-directory'/python/gdb/command and
4550 'data-directory'/python/gdb/function are now automatically loaded
4553 ** Blocks now provide four new attributes. global_block and
4554 static_block will return the global and static blocks
4555 respectively. is_static and is_global are boolean attributes
4556 that indicate if the block is one of those two types.
4558 ** Symbols now provide the "type" attribute, the type of the symbol.
4560 ** The "gdb.breakpoint" function has been deprecated in favor of
4563 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4564 of a function. This class is based on the "finish" command
4565 available in the CLI.
4567 ** Type objects for struct and union types now allow access to
4568 the fields using standard Python dictionary (mapping) methods.
4569 For example, "some_type['myfield']" now works, as does
4570 "some_type.items()".
4572 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4575 ** A new function, "deep_items" has been added to the gdb.types
4576 module in the GDB Python modules library. This function returns
4577 an iterator over the fields of a struct or union type. Unlike
4578 the standard Python "iteritems" method, it will recursively traverse
4579 any anonymous fields.
4583 ** "*stopped" events can report several new "reason"s, such as
4586 ** Breakpoint changes are now notified using new async records, like
4587 "=breakpoint-modified".
4589 ** New command -ada-task-info.
4591 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4592 $sdir specifies the default system locations of shared libraries.
4593 $pdir specifies the directory where the libpthread used by the application
4596 GDB no longer looks in $sdir and $pdir after it has searched the directories
4597 mentioned in libthread-db-search-path. If you want to search those
4598 directories, they must be specified in libthread-db-search-path.
4599 The default value of libthread-db-search-path on GNU/Linux and Solaris
4600 systems is now "$sdir:$pdir".
4602 $pdir is not supported by gdbserver, it is currently ignored.
4603 $sdir is supported by gdbserver.
4605 * New configure option --with-iconv-bin.
4606 When using the internationalization support like the one in the GNU C
4607 library, GDB will invoke the "iconv" program to get a list of supported
4608 character sets. If this program lives in a non-standard location, one can
4609 use this option to specify where to find it.
4611 * When natively debugging programs on PowerPC BookE processors running
4612 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4613 watchpoints, which specify a mask in addition to an address to watch.
4614 The mask specifies that some bits of an address (the bits which are
4615 reset in the mask) should be ignored when matching the address accessed
4616 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4617 section in the user manual for more details.
4619 * The new option --once causes GDBserver to stop listening for connections once
4620 the first connection is made. The listening port used by GDBserver will
4621 become available after that.
4623 * New commands "info macros" and "alias" have been added.
4625 * New function parameters suffix @entry specifies value of function parameter
4626 at the time the function got called. Entry values are available only since
4632 "!" is now an alias of the "shell" command.
4633 Note that no space is needed between "!" and SHELL COMMAND.
4637 watch EXPRESSION mask MASK_VALUE
4638 The watch command now supports the mask argument which allows creation
4639 of masked watchpoints, if the current architecture supports this feature.
4641 info auto-load-scripts [REGEXP]
4642 This command was formerly named "maintenance print section-scripts".
4643 It is now generally useful and is no longer a maintenance-only command.
4645 info macro [-all] [--] MACRO
4646 The info macro command has new options `-all' and `--'. The first for
4647 printing all definitions of a macro. The second for explicitly specifying
4648 the end of arguments and the beginning of the macro name in case the macro
4649 name starts with a hyphen.
4651 collect[/s] EXPRESSIONS
4652 The tracepoint collect command now takes an optional modifier "/s"
4653 that directs it to dereference pointer-to-character types and
4654 collect the bytes of memory up to a zero byte. The behavior is
4655 similar to what you see when you use the regular print command on a
4656 string. An optional integer following the "/s" sets a bound on the
4657 number of bytes that will be collected.
4660 The trace start command now interprets any supplied arguments as a
4661 note to be recorded with the trace run, with an effect similar to
4662 setting the variable trace-notes.
4665 The trace stop command now interprets any arguments as a note to be
4666 mentioned along with the tstatus report that the trace was stopped
4667 with a command. The effect is similar to setting the variable
4670 * Tracepoints can now be enabled and disabled at any time after a trace
4671 experiment has been started using the standard "enable" and "disable"
4672 commands. It is now possible to start a trace experiment with no enabled
4673 tracepoints; GDB will display a warning, but will allow the experiment to
4674 begin, assuming that tracepoints will be enabled as needed while the trace
4677 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4678 locations with 4-byte instructions, when they were previously
4679 limited to locations with instructions of 5 bytes or longer.
4683 set debug dwarf2-read
4684 show debug dwarf2-read
4685 Turns on or off display of debugging messages related to reading
4686 DWARF debug info. The default is off.
4688 set debug symtab-create
4689 show debug symtab-create
4690 Turns on or off display of debugging messages related to symbol table
4691 creation. The default is off.
4694 show extended-prompt
4695 Set the GDB prompt, and allow escape sequences to be inserted to
4696 display miscellaneous information (see 'help set extended-prompt'
4697 for the list of sequences). This prompt (and any information
4698 accessed through the escape sequences) is updated every time the
4699 prompt is displayed.
4701 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4702 show print entry-values
4703 Set printing of frame argument values at function entry. In some cases
4704 GDB can determine the value of function argument which was passed by the
4705 function caller, even if the value was modified inside the called function.
4707 set debug entry-values
4708 show debug entry-values
4709 Control display of debugging info for determining frame argument values at
4710 function entry and virtual tail call frames.
4712 set basenames-may-differ
4713 show basenames-may-differ
4714 Set whether a source file may have multiple base names.
4715 (A "base name" is the name of a file with the directory part removed.
4716 Example: The base name of "/home/user/hello.c" is "hello.c".)
4717 If set, GDB will canonicalize file names (e.g., expand symlinks)
4718 before comparing them. Canonicalization is an expensive operation,
4719 but it allows the same file be known by more than one base name.
4720 If not set (the default), all source files are assumed to have just
4721 one base name, and gdb will do file name comparisons more efficiently.
4727 Set a user name and notes for the current and any future trace runs.
4728 This is useful for long-running and/or disconnected traces, to
4729 inform others (or yourself) as to who is running the trace, supply
4730 contact information, or otherwise explain what is going on.
4732 set trace-stop-notes
4733 show trace-stop-notes
4734 Set a note attached to the trace run, that is displayed when the
4735 trace has been stopped by a tstop command. This is useful for
4736 instance as an explanation, if you are stopping a trace run that was
4737 started by someone else.
4739 * New remote packets
4743 Dynamically enable a tracepoint in a started trace experiment.
4747 Dynamically disable a tracepoint in a started trace experiment.
4751 Set the user and notes of the trace run.
4755 Query the current status of a tracepoint.
4759 Query the minimum length of instruction at which a fast tracepoint may
4762 * Dcache size (number of lines) and line-size are now runtime-configurable
4763 via "set dcache line" and "set dcache line-size" commands.
4767 Texas Instruments TMS320C6x tic6x-*-*
4771 Renesas RL78 rl78-*-elf
4773 *** Changes in GDB 7.3.1
4775 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4777 *** Changes in GDB 7.3
4779 * GDB has a new command: "thread find [REGEXP]".
4780 It finds the thread id whose name, target id, or thread extra info
4781 matches the given regular expression.
4783 * The "catch syscall" command now works on mips*-linux* targets.
4785 * The -data-disassemble MI command now supports modes 2 and 3 for
4786 dumping the instruction opcodes.
4788 * New command line options
4790 -data-directory DIR Specify DIR as the "data-directory".
4791 This is mostly for testing purposes.
4793 * The "maint set python auto-load on|off" command has been renamed to
4794 "set auto-load-scripts on|off".
4796 * GDB has a new command: "set directories".
4797 It is like the "dir" command except that it replaces the
4798 source path list instead of augmenting it.
4800 * GDB now understands thread names.
4802 On GNU/Linux, "info threads" will display the thread name as set by
4803 prctl or pthread_setname_np.
4805 There is also a new command, "thread name", which can be used to
4806 assign a name internally for GDB to display.
4809 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4810 has been integrated into GDB.
4814 ** The function gdb.Write now accepts an optional keyword 'stream'.
4815 This keyword, when provided, will direct the output to either
4816 stdout, stderr, or GDB's logging output.
4818 ** Parameters can now be be sub-classed in Python, and in particular
4819 you may implement the get_set_doc and get_show_doc functions.
4820 This improves how Parameter set/show documentation is processed
4821 and allows for more dynamic content.
4823 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4824 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4825 have an is_valid method.
4827 ** Breakpoints can now be sub-classed in Python, and in particular
4828 you may implement a 'stop' function that is executed each time
4829 the inferior reaches that breakpoint.
4831 ** New function gdb.lookup_global_symbol looks up a global symbol.
4833 ** GDB values in Python are now callable if the value represents a
4834 function. For example, if 'some_value' represents a function that
4835 takes two integer parameters and returns a value, you can call
4836 that function like so:
4838 result = some_value (10,20)
4840 ** Module gdb.types has been added.
4841 It contains a collection of utilities for working with gdb.Types objects:
4842 get_basic_type, has_field, make_enum_dict.
4844 ** Module gdb.printing has been added.
4845 It contains utilities for writing and registering pretty-printers.
4846 New classes: PrettyPrinter, SubPrettyPrinter,
4847 RegexpCollectionPrettyPrinter.
4848 New function: register_pretty_printer.
4850 ** New commands "info pretty-printers", "enable pretty-printer" and
4851 "disable pretty-printer" have been added.
4853 ** gdb.parameter("directories") is now available.
4855 ** New function gdb.newest_frame returns the newest frame in the
4858 ** The gdb.InferiorThread class has a new "name" attribute. This
4859 holds the thread's name.
4861 ** Python Support for Inferior events.
4862 Python scripts can add observers to be notified of events
4863 occurring in the process being debugged.
4864 The following events are currently supported:
4865 - gdb.events.cont Continue event.
4866 - gdb.events.exited Inferior exited event.
4867 - gdb.events.stop Signal received, and Breakpoint hit events.
4871 ** GDB now puts template parameters in scope when debugging in an
4872 instantiation. For example, if you have:
4874 template<int X> int func (void) { return X; }
4876 then if you step into func<5>, "print X" will show "5". This
4877 feature requires proper debuginfo support from the compiler; it
4878 was added to GCC 4.5.
4880 ** The motion commands "next", "finish", "until", and "advance" now
4881 work better when exceptions are thrown. In particular, GDB will
4882 no longer lose control of the inferior; instead, the GDB will
4883 stop the inferior at the point at which the exception is caught.
4884 This functionality requires a change in the exception handling
4885 code that was introduced in GCC 4.5.
4887 * GDB now follows GCC's rules on accessing volatile objects when
4888 reading or writing target state during expression evaluation.
4889 One notable difference to prior behavior is that "print x = 0"
4890 no longer generates a read of x; the value of the assignment is
4891 now always taken directly from the value being assigned.
4893 * GDB now has some support for using labels in the program's source in
4894 linespecs. For instance, you can use "advance label" to continue
4895 execution to a label.
4897 * GDB now has support for reading and writing a new .gdb_index
4898 section. This section holds a fast index of DWARF debugging
4899 information and can be used to greatly speed up GDB startup and
4900 operation. See the documentation for `save gdb-index' for details.
4902 * The "watch" command now accepts an optional "-location" argument.
4903 When used, this causes GDB to watch the memory referred to by the
4904 expression. Such a watchpoint is never deleted due to it going out
4907 * GDB now supports thread debugging of core dumps on GNU/Linux.
4909 GDB now activates thread debugging using the libthread_db library
4910 when debugging GNU/Linux core dumps, similarly to when debugging
4911 live processes. As a result, when debugging a core dump file, GDB
4912 is now able to display pthread_t ids of threads. For example, "info
4913 threads" shows the same output as when debugging the process when it
4914 was live. In earlier releases, you'd see something like this:
4917 * 1 LWP 6780 main () at main.c:10
4919 While now you see this:
4922 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4924 It is also now possible to inspect TLS variables when debugging core
4927 When debugging a core dump generated on a machine other than the one
4928 used to run GDB, you may need to point GDB at the correct
4929 libthread_db library with the "set libthread-db-search-path"
4930 command. See the user manual for more details on this command.
4932 * When natively debugging programs on PowerPC BookE processors running
4933 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4934 which stop execution of the inferior whenever it executes an instruction
4935 at any address within the specified range. See the "PowerPC Embedded"
4936 section in the user manual for more details.
4938 * New features in the GDB remote stub, GDBserver
4940 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4941 and i686 LynxOS (version 5.x).
4943 ** GDBserver is now supported on Blackfin Linux.
4945 * New native configurations
4947 ia64 HP-UX ia64-*-hpux*
4951 Analog Devices, Inc. Blackfin Processor bfin-*
4953 * Ada task switching is now supported on sparc-elf targets when
4954 debugging a program using the Ravenscar Profile. For more information,
4955 see the "Tasking Support when using the Ravenscar Profile" section
4956 in the GDB user manual.
4958 * Guile support was removed.
4960 * New features in the GNU simulator
4962 ** The --map-info flag lists all known core mappings.
4964 ** CFI flashes may be simulated via the "cfi" device.
4966 *** Changes in GDB 7.2
4968 * Shared library support for remote targets by default
4970 When GDB is configured for a generic, non-OS specific target, like
4971 for example, --target=arm-eabi or one of the many *-*-elf targets,
4972 GDB now queries remote stubs for loaded shared libraries using the
4973 `qXfer:libraries:read' packet. Previously, shared library support
4974 was always disabled for such configurations.
4978 ** Argument Dependent Lookup (ADL)
4980 In C++ ADL lookup directs function search to the namespaces of its
4981 arguments even if the namespace has not been imported.
4991 Here the compiler will search for `foo' in the namespace of 'b'
4992 and find A::foo. GDB now supports this. This construct is commonly
4993 used in the Standard Template Library for operators.
4995 ** Improved User Defined Operator Support
4997 In addition to member operators, GDB now supports lookup of operators
4998 defined in a namespace and imported with a `using' directive, operators
4999 defined in the global scope, operators imported implicitly from an
5000 anonymous namespace, and the ADL operators mentioned in the previous
5002 GDB now also supports proper overload resolution for all the previously
5003 mentioned flavors of operators.
5005 ** static const class members
5007 Printing of static const class members that are initialized in the
5008 class definition has been fixed.
5010 * Windows Thread Information Block access.
5012 On Windows targets, GDB now supports displaying the Windows Thread
5013 Information Block (TIB) structure. This structure is visible either
5014 by using the new command `info w32 thread-information-block' or, by
5015 dereferencing the new convenience variable named `$_tlb', a
5016 thread-specific pointer to the TIB. This feature is also supported
5017 when remote debugging using GDBserver.
5019 * Static tracepoints
5021 Static tracepoints are calls in the user program into a tracing
5022 library. One such library is a port of the LTTng kernel tracer to
5023 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
5024 When debugging with GDBserver, GDB now supports combining the GDB
5025 tracepoint machinery with such libraries. For example: the user can
5026 use GDB to probe a static tracepoint marker (a call from the user
5027 program into the tracing library) with the new "strace" command (see
5028 "New commands" below). This creates a "static tracepoint" in the
5029 breakpoint list, that can be manipulated with the same feature set
5030 as fast and regular tracepoints. E.g., collect registers, local and
5031 global variables, collect trace state variables, and define
5032 tracepoint conditions. In addition, the user can collect extra
5033 static tracepoint marker specific data, by collecting the new
5034 $_sdata internal variable. When analyzing the trace buffer, you can
5035 inspect $_sdata like any other variable available to GDB. For more
5036 information, see the "Tracepoints" chapter in GDB user manual. New
5037 remote packets have been defined to support static tracepoints, see
5038 the "New remote packets" section below.
5040 * Better reconstruction of tracepoints after disconnected tracing
5042 GDB will attempt to download the original source form of tracepoint
5043 definitions when starting a trace run, and then will upload these
5044 upon reconnection to the target, resulting in a more accurate
5045 reconstruction of the tracepoints that are in use on the target.
5049 You can now exercise direct control over the ways that GDB can
5050 affect your program. For instance, you can disallow the setting of
5051 breakpoints, so that the program can run continuously (assuming
5052 non-stop mode). In addition, the "observer" variable is available
5053 to switch all of the different controls; in observer mode, GDB
5054 cannot affect the target's behavior at all, which is useful for
5055 tasks like diagnosing live systems in the field.
5057 * The new convenience variable $_thread holds the number of the
5060 * New remote packets
5064 Return the address of the Windows Thread Information Block of a given thread.
5068 In response to several of the tracepoint packets, the target may now
5069 also respond with a number of intermediate `qRelocInsn' request
5070 packets before the final result packet, to have GDB handle
5071 relocating an instruction to execute at a different address. This
5072 is particularly useful for stubs that support fast tracepoints. GDB
5073 reports support for this feature in the qSupported packet.
5077 List static tracepoint markers in the target program.
5081 List static tracepoint markers at a given address in the target
5084 qXfer:statictrace:read
5086 Read the static trace data collected (by a `collect $_sdata'
5087 tracepoint action). The remote stub reports support for this packet
5088 to gdb's qSupported query.
5092 Send the current settings of GDB's permission flags.
5096 Send part of the source (textual) form of a tracepoint definition,
5097 which includes location, conditional, and action list.
5099 * The source command now accepts a -s option to force searching for the
5100 script in the source search path even if the script name specifies
5103 * New features in the GDB remote stub, GDBserver
5105 - GDBserver now support tracepoints (including fast tracepoints, and
5106 static tracepoints). The feature is currently supported by the
5107 i386-linux and amd64-linux builds. See the "Tracepoints support
5108 in gdbserver" section in the manual for more information.
5110 GDBserver JIT compiles the tracepoint's conditional agent
5111 expression bytecode into native code whenever possible for low
5112 overhead dynamic tracepoints conditionals. For such tracepoints,
5113 an expression that examines program state is evaluated when the
5114 tracepoint is reached, in order to determine whether to capture
5115 trace data. If the condition is simple and false, processing the
5116 tracepoint finishes very quickly and no data is gathered.
5118 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
5119 for static tracepoints support.
5121 - GDBserver now supports x86_64 Windows 64-bit debugging.
5123 * GDB now sends xmlRegisters= in qSupported packet to indicate that
5124 it understands register description.
5126 * The --batch flag now disables pagination and queries.
5128 * X86 general purpose registers
5130 GDB now supports reading/writing byte, word and double-word x86
5131 general purpose registers directly. This means you can use, say,
5132 $ah or $ax to refer, respectively, to the byte register AH and
5133 16-bit word register AX that are actually portions of the 32-bit
5134 register EAX or 64-bit register RAX.
5136 * The `commands' command now accepts a range of breakpoints to modify.
5137 A plain `commands' following a command that creates multiple
5138 breakpoints affects all the breakpoints set by that command. This
5139 applies to breakpoints set by `rbreak', and also applies when a
5140 single `break' command creates multiple breakpoints (e.g.,
5141 breakpoints on overloaded c++ functions).
5143 * The `rbreak' command now accepts a filename specification as part of
5144 its argument, limiting the functions selected by the regex to those
5145 in the specified file.
5147 * Support for remote debugging Windows and SymbianOS shared libraries
5148 from Unix hosts has been improved. Non Windows GDB builds now can
5149 understand target reported file names that follow MS-DOS based file
5150 system semantics, such as file names that include drive letters and
5151 use the backslash character as directory separator. This makes it
5152 possible to transparently use the "set sysroot" and "set
5153 solib-search-path" on Unix hosts to point as host copies of the
5154 target's shared libraries. See the new command "set
5155 target-file-system-kind" described below, and the "Commands to
5156 specify files" section in the user manual for more information.
5160 eval template, expressions...
5161 Convert the values of one or more expressions under the control
5162 of the string template to a command line, and call it.
5164 set target-file-system-kind unix|dos-based|auto
5165 show target-file-system-kind
5166 Set or show the assumed file system kind for target reported file
5169 save breakpoints <filename>
5170 Save all current breakpoint definitions to a file suitable for use
5171 in a later debugging session. To read the saved breakpoint
5172 definitions, use the `source' command.
5174 `save tracepoints' is a new alias for `save-tracepoints'. The latter
5177 info static-tracepoint-markers
5178 Display information about static tracepoint markers in the target.
5180 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5181 Define a static tracepoint by probing a marker at the given
5182 function, line, address, or marker ID.
5186 Enable and disable observer mode.
5188 set may-write-registers on|off
5189 set may-write-memory on|off
5190 set may-insert-breakpoints on|off
5191 set may-insert-tracepoints on|off
5192 set may-insert-fast-tracepoints on|off
5193 set may-interrupt on|off
5194 Set individual permissions for GDB effects on the target. Note that
5195 some of these settings can have undesirable or surprising
5196 consequences, particularly when changed in the middle of a session.
5197 For instance, disabling the writing of memory can prevent
5198 breakpoints from being inserted, cause single-stepping to fail, or
5199 even crash your program, if you disable after breakpoints have been
5200 inserted. However, GDB should not crash.
5202 set record memory-query on|off
5203 show record memory-query
5204 Control whether to stop the inferior if memory changes caused
5205 by an instruction cannot be recorded.
5210 The disassemble command now supports "start,+length" form of two arguments.
5214 ** GDB now provides a new directory location, called the python directory,
5215 where Python scripts written for GDB can be installed. The location
5216 of that directory is <data-directory>/python, where <data-directory>
5217 is the GDB data directory. For more details, see section `Scripting
5218 GDB using Python' in the manual.
5220 ** The GDB Python API now has access to breakpoints, symbols, symbol
5221 tables, program spaces, inferiors, threads and frame's code blocks.
5222 Additionally, GDB Parameters can now be created from the API, and
5223 manipulated via set/show in the CLI.
5225 ** New functions gdb.target_charset, gdb.target_wide_charset,
5226 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5228 ** New exception gdb.GdbError.
5230 ** Pretty-printers are now also looked up in the current program space.
5232 ** Pretty-printers can now be individually enabled and disabled.
5234 ** GDB now looks for names of Python scripts to auto-load in a
5235 special section named `.debug_gdb_scripts', in addition to looking
5236 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5238 * Tracepoint actions were unified with breakpoint commands. In particular,
5239 there are no longer differences in "info break" output for breakpoints and
5240 tracepoints and the "commands" command can be used for both tracepoints and
5241 regular breakpoints.
5245 ARM Symbian arm*-*-symbianelf*
5247 * D language support.
5248 GDB now supports debugging programs written in the D programming
5251 * GDB now supports the extended ptrace interface for PowerPC which is
5252 available since Linux kernel version 2.6.34. This automatically enables
5253 any hardware breakpoints and additional hardware watchpoints available in
5254 the processor. The old ptrace interface exposes just one hardware
5255 watchpoint and no hardware breakpoints.
5257 * GDB is now able to use the Data Value Compare (DVC) register available on
5258 embedded PowerPC processors to implement in hardware simple watchpoint
5259 conditions of the form:
5261 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5263 This works in native GDB running on Linux kernels with the extended ptrace
5264 interface mentioned above.
5266 *** Changes in GDB 7.1
5270 ** Namespace Support
5272 GDB now supports importing of namespaces in C++. This enables the
5273 user to inspect variables from imported namespaces. Support for
5274 namepace aliasing has also been added. So, if a namespace is
5275 aliased in the current scope (e.g. namepace C=A; ) the user can
5276 print variables using the alias (e.g. (gdb) print C::x).
5280 All known bugs relating to the printing of virtual base class were
5281 fixed. It is now possible to call overloaded static methods using a
5286 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5287 and reinterpret_cast<> are now handled by the C++ expression parser.
5291 Xilinx MicroBlaze microblaze-*-*
5296 Xilinx MicroBlaze microblaze
5299 * Multi-program debugging.
5301 GDB now has support for multi-program (a.k.a. multi-executable or
5302 multi-exec) debugging. This allows for debugging multiple inferiors
5303 simultaneously each running a different program under the same GDB
5304 session. See "Debugging Multiple Inferiors and Programs" in the
5305 manual for more information. This implied some user visible changes
5306 in the multi-inferior support. For example, "info inferiors" now
5307 lists inferiors that are not running yet or that have exited
5308 already. See also "New commands" and "New options" below.
5310 * New tracing features
5312 GDB's tracepoint facility now includes several new features:
5314 ** Trace state variables
5316 GDB tracepoints now include support for trace state variables, which
5317 are variables managed by the target agent during a tracing
5318 experiment. They are useful for tracepoints that trigger each
5319 other, so for instance one tracepoint can count hits in a variable,
5320 and then a second tracepoint has a condition that is true when the
5321 count reaches a particular value. Trace state variables share the
5322 $-syntax of GDB convenience variables, and can appear in both
5323 tracepoint actions and condition expressions. Use the "tvariable"
5324 command to create, and "info tvariables" to view; see "Trace State
5325 Variables" in the manual for more detail.
5329 GDB now includes an option for defining fast tracepoints, which
5330 targets may implement more efficiently, such as by installing a jump
5331 into the target agent rather than a trap instruction. The resulting
5332 speedup can be by two orders of magnitude or more, although the
5333 tradeoff is that some program locations on some target architectures
5334 might not allow fast tracepoint installation, for instance if the
5335 instruction to be replaced is shorter than the jump. To request a
5336 fast tracepoint, use the "ftrace" command, with syntax identical to
5337 the regular trace command.
5339 ** Disconnected tracing
5341 It is now possible to detach GDB from the target while it is running
5342 a trace experiment, then reconnect later to see how the experiment
5343 is going. In addition, a new variable disconnected-tracing lets you
5344 tell the target agent whether to continue running a trace if the
5345 connection is lost unexpectedly.
5349 GDB now has the ability to save the trace buffer into a file, and
5350 then use that file as a target, similarly to you can do with
5351 corefiles. You can select trace frames, print data that was
5352 collected in them, and use tstatus to display the state of the
5353 tracing run at the moment that it was saved. To create a trace
5354 file, use "tsave <filename>", and to use it, do "target tfile
5357 ** Circular trace buffer
5359 You can ask the target agent to handle the trace buffer as a
5360 circular buffer, discarding the oldest trace frames to make room for
5361 newer ones, by setting circular-trace-buffer to on. This feature may
5362 not be available for all target agents.
5367 The disassemble command, when invoked with two arguments, now requires
5368 the arguments to be comma-separated.
5371 The info variables command now displays variable definitions. Files
5372 which only declare a variable are not shown.
5375 The source command is now capable of sourcing Python scripts.
5376 This feature is dependent on the debugger being build with Python
5379 Related to this enhancement is also the introduction of a new command
5380 "set script-extension" (see below).
5382 * New commands (for set/show, see "New options" below)
5384 record save [<FILENAME>]
5385 Save a file (in core file format) containing the process record
5386 execution log for replay debugging at a later time.
5388 record restore <FILENAME>
5389 Restore the process record execution log that was saved at an
5390 earlier time, for replay debugging.
5392 add-inferior [-copies <N>] [-exec <FILENAME>]
5395 clone-inferior [-copies <N>] [ID]
5396 Make a new inferior ready to execute the same program another
5397 inferior has loaded.
5402 maint info program-spaces
5403 List the program spaces loaded into GDB.
5405 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5406 show remote interrupt-sequence
5407 Allow the user to select one of ^C, a BREAK signal or BREAK-g
5408 as the sequence to the remote target in order to interrupt the execution.
5409 Ctrl-C is a default. Some system prefers BREAK which is high level of
5410 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
5411 Magic SysRq g. It is BREAK signal and character 'g'.
5413 set remote interrupt-on-connect [on | off]
5414 show remote interrupt-on-connect
5415 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5416 remote target when gdb connects to it. This is needed when you debug
5419 set remotebreak [on | off]
5421 Deprecated. Use "set/show remote interrupt-sequence" instead.
5423 tvariable $NAME [ = EXP ]
5424 Create or modify a trace state variable.
5427 List trace state variables and their values.
5429 delete tvariable $NAME ...
5430 Delete one or more trace state variables.
5433 Evaluate the given expressions without collecting anything into the
5434 trace buffer. (Valid in tracepoint actions only.)
5436 ftrace FN / FILE:LINE / *ADDR
5437 Define a fast tracepoint at the given function, line, or address.
5439 * New expression syntax
5441 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5442 GDB now parses 0b101010 identically with 42.
5446 set follow-exec-mode new|same
5447 show follow-exec-mode
5448 Control whether GDB reuses the same inferior across an exec call or
5449 creates a new one. This is useful to be able to restart the old
5450 executable after the inferior having done an exec call.
5452 set default-collect EXPR, ...
5453 show default-collect
5454 Define a list of expressions to be collected at each tracepoint.
5455 This is a useful way to ensure essential items are not overlooked,
5456 such as registers or a critical global variable.
5458 set disconnected-tracing
5459 show disconnected-tracing
5460 If set to 1, the target is instructed to continue tracing if it
5461 loses its connection to GDB. If 0, the target is to stop tracing
5464 set circular-trace-buffer
5465 show circular-trace-buffer
5466 If set to on, the target is instructed to use a circular trace buffer
5467 and discard the oldest trace frames instead of stopping the trace due
5468 to a full trace buffer. If set to off, the trace stops when the buffer
5469 fills up. Some targets may not support this.
5471 set script-extension off|soft|strict
5472 show script-extension
5473 If set to "off", the debugger does not perform any script language
5474 recognition, and all sourced files are assumed to be GDB scripts.
5475 If set to "soft" (the default), files are sourced according to
5476 filename extension, falling back to GDB scripts if the first
5478 If set to "strict", files are sourced according to filename extension.
5480 set ada trust-PAD-over-XVS on|off
5481 show ada trust-PAD-over-XVS
5482 If off, activate a workaround against a bug in the debugging information
5483 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5484 the GCC sources for more information about the GNAT encoding and
5485 PAD types in particular). It is always safe to set this option to
5486 off, but this introduces a slight performance penalty. The default
5489 * Python API Improvements
5491 ** GDB provides the new class gdb.LazyString. This is useful in
5492 some pretty-printing cases. The new method gdb.Value.lazy_string
5493 provides a simple way to create objects of this type.
5495 ** The fields returned by gdb.Type.fields now have an
5496 `is_base_class' attribute.
5498 ** The new method gdb.Type.range returns the range of an array type.
5500 ** The new method gdb.parse_and_eval can be used to parse and
5501 evaluate an expression.
5503 * New remote packets
5506 Define a trace state variable.
5509 Get the current value of a trace state variable.
5512 Set desired tracing behavior upon disconnection.
5515 Set the trace buffer to be linear or circular.
5518 Get data about the tracepoints currently in use.
5522 Process record now works correctly with hardware watchpoints.
5524 Multiple bug fixes have been made to the mips-irix port, making it
5525 much more reliable. In particular:
5526 - Debugging threaded applications is now possible again. Previously,
5527 GDB would hang while starting the program, or while waiting for
5528 the program to stop at a breakpoint.
5529 - Attaching to a running process no longer hangs.
5530 - An error occurring while loading a core file has been fixed.
5531 - Changing the value of the PC register now works again. This fixes
5532 problems observed when using the "jump" command, or when calling
5533 a function from GDB, or even when assigning a new value to $pc.
5534 - With the "finish" and "return" commands, the return value for functions
5535 returning a small array is now correctly printed.
5536 - It is now possible to break on shared library code which gets executed
5537 during a shared library init phase (code executed while executing
5538 their .init section). Previously, the breakpoint would have no effect.
5539 - GDB is now able to backtrace through the signal handler for
5540 non-threaded programs.
5542 PIE (Position Independent Executable) programs debugging is now supported.
5543 This includes debugging execution of PIC (Position Independent Code) shared
5544 libraries although for that, it should be possible to run such libraries as an
5547 *** Changes in GDB 7.0
5549 * GDB now has an interface for JIT compilation. Applications that
5550 dynamically generate code can create symbol files in memory and register
5551 them with GDB. For users, the feature should work transparently, and
5552 for JIT developers, the interface is documented in the GDB manual in the
5553 "JIT Compilation Interface" chapter.
5555 * Tracepoints may now be conditional. The syntax is as for
5556 breakpoints; either an "if" clause appended to the "trace" command,
5557 or the "condition" command is available. GDB sends the condition to
5558 the target for evaluation using the same bytecode format as is used
5559 for tracepoint actions.
5561 * The disassemble command now supports: an optional /r modifier, print the
5562 raw instructions in hex as well as in symbolic form, and an optional /m
5563 modifier to print mixed source+assembly.
5565 * Process record and replay
5567 In a architecture environment that supports ``process record and
5568 replay'', ``process record and replay'' target can record a log of
5569 the process execution, and replay it with both forward and reverse
5572 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5573 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5574 set execution-direction {forward|reverse}, for targets that support
5577 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5578 feature is available with a native GDB running on kernel version
5581 * GDB now has support for multi-byte and wide character sets on the
5582 target. Strings whose character type is wchar_t, char16_t, or
5583 char32_t are now correctly printed. GDB supports wide- and unicode-
5584 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5585 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5586 `printf'. This feature requires iconv to work properly; if your
5587 system does not have a working iconv, GDB can use GNU libiconv. See
5588 the installation instructions for more information.
5590 * GDB now supports automatic retrieval of shared library files from
5591 remote targets. To use this feature, specify a system root that begins
5592 with the `remote:' prefix, either via the `set sysroot' command or via
5593 the `--with-sysroot' configure-time option.
5595 * "info sharedlibrary" now takes an optional regex of libraries to show,
5596 and it now reports if a shared library has no debugging information.
5598 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5599 now complete on file names.
5601 * When completing in expressions, gdb will attempt to limit
5602 completions to allowable structure or union fields, where appropriate.
5603 For instance, consider:
5605 # struct example { int f1; double f2; };
5606 # struct example variable;
5609 If the user types TAB at the end of this command line, the available
5610 completions will be "f1" and "f2".
5612 * Inlined functions are now supported. They show up in backtraces, and
5613 the "step", "next", and "finish" commands handle them automatically.
5615 * GDB now supports the token-splicing (##) and stringification (#)
5616 operators when expanding macros. It also supports variable-arity
5619 * GDB now supports inspecting extra signal information, exported by
5620 the new $_siginfo convenience variable. The feature is currently
5621 implemented on linux ARM, i386 and amd64.
5623 * GDB can now display the VFP floating point registers and NEON vector
5624 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5625 can provide these registers (requires Linux 2.6.30 or later). Remote
5626 and simulator targets may also provide them.
5628 * New remote packets
5631 Search memory for a sequence of bytes.
5634 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5635 operation over reliable transport links. Use of this packet is
5636 controlled by the `set remote noack-packet' command.
5639 Kill the process with the specified process ID. Use this in preference
5640 to `k' when multiprocess protocol extensions are supported.
5643 Obtains additional operating system information
5647 Read or write additional signal information.
5649 * Removed remote protocol undocumented extension
5651 An undocumented extension to the remote protocol's `S' stop reply
5652 packet that permitted the stub to pass a process id was removed.
5653 Remote servers should use the `T' stop reply packet instead.
5655 * GDB now supports multiple function calling conventions according to the
5656 DWARF-2 DW_AT_calling_convention function attribute.
5658 * The SH target utilizes the aforementioned change to distinguish between gcc
5659 and Renesas calling convention. It also adds the new CLI commands
5660 `set/show sh calling-convention'.
5662 * GDB can now read compressed debug sections, as produced by GNU gold
5663 with the --compress-debug-sections=zlib flag.
5665 * 64-bit core files are now supported on AIX.
5667 * Thread switching is now supported on Tru64.
5669 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5670 which will be allocated using malloc later in program execution.
5672 * The qXfer:libraries:read remote protocol packet now allows passing a
5673 list of section offsets.
5675 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5676 conditions handling signals delivered during attach or thread creation
5677 have also been fixed.
5679 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5680 From the user's standpoint, all unqualified instances of True and False
5681 are treated as the standard definitions, regardless of context.
5683 * GDB now parses C++ symbol and type names more flexibly. For
5686 template<typename T> class C { };
5689 GDB will now correctly handle all of:
5691 ptype C<char const *>
5692 ptype C<char const*>
5693 ptype C<const char *>
5694 ptype C<const char*>
5696 * New features in the GDB remote stub, gdbserver
5698 - The "--wrapper" command-line argument tells gdbserver to use a
5699 wrapper program to launch programs for debugging.
5701 - On PowerPC and S/390 targets, it is now possible to use a single
5702 gdbserver executable to debug both 32-bit and 64-bit programs.
5703 (This requires gdbserver itself to be built as a 64-bit executable.)
5705 - gdbserver uses the new noack protocol mode for TCP connections to
5706 reduce communications latency, if also supported and enabled in GDB.
5708 - Support for the sparc64-linux-gnu target is now included in
5711 - The amd64-linux build of gdbserver now supports debugging both
5712 32-bit and 64-bit programs.
5714 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5715 now support hardware watchpoints, and will use them automatically
5720 GDB now has support for scripting using Python. Whether this is
5721 available is determined at configure time.
5723 New GDB commands can now be written in Python.
5725 * Ada tasking support
5727 Ada tasks can now be inspected in GDB. The following commands have
5731 Print the list of Ada tasks.
5733 Print detailed information about task number N.
5735 Print the task number of the current task.
5737 Switch the context of debugging to task number N.
5739 * Support for user-defined prefixed commands. The "define" command can
5740 add new commands to existing prefixes, e.g. "target".
5742 * Multi-inferior, multi-process debugging.
5744 GDB now has generalized support for multi-inferior debugging. See
5745 "Debugging Multiple Inferiors" in the manual for more information.
5746 Although availability still depends on target support, the command
5747 set is more uniform now. The GNU/Linux specific multi-forks support
5748 has been migrated to this new framework. This implied some user
5749 visible changes; see "New commands" and also "Removed commands"
5752 * Target descriptions can now describe the target OS ABI. See the
5753 "Target Description Format" section in the user manual for more
5756 * Target descriptions can now describe "compatible" architectures
5757 to indicate that the target can execute applications for a different
5758 architecture in addition to those for the main target architecture.
5759 See the "Target Description Format" section in the user manual for
5762 * Multi-architecture debugging.
5764 GDB now includes general supports for debugging applications on
5765 hybrid systems that use more than one single processor architecture
5766 at the same time. Each such hybrid architecture still requires
5767 specific support to be added. The only hybrid architecture supported
5768 in this version of GDB is the Cell Broadband Engine.
5770 * GDB now supports integrated debugging of Cell/B.E. applications that
5771 use both the PPU and SPU architectures. To enable support for hybrid
5772 Cell/B.E. debugging, you need to configure GDB to support both the
5773 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5774 --enable-targets configure option.
5776 * Non-stop mode debugging.
5778 For some targets, GDB now supports an optional mode of operation in
5779 which you can examine stopped threads while other threads continue
5780 to execute freely. This is referred to as non-stop mode, with the
5781 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5782 section in the user manual for more information.
5784 To be able to support remote non-stop debugging, a remote stub needs
5785 to implement the non-stop mode remote protocol extensions, as
5786 described in the "Remote Non-Stop" section of the user manual. The
5787 GDB remote stub, gdbserver, has been adjusted to support these
5788 extensions on linux targets.
5790 * New commands (for set/show, see "New options" below)
5792 catch syscall [NAME(S) | NUMBER(S)]
5793 Catch system calls. Arguments, which should be names of system
5794 calls or their numbers, mean catch only those syscalls. Without
5795 arguments, every syscall will be caught. When the inferior issues
5796 any of the specified syscalls, GDB will stop and announce the system
5797 call, both when it is called and when its call returns. This
5798 feature is currently available with a native GDB running on the
5799 Linux Kernel, under the following architectures: x86, x86_64,
5800 PowerPC and PowerPC64.
5802 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5804 Search memory for a sequence of bytes.
5806 maint set python print-stack
5807 maint show python print-stack
5808 Show a stack trace when an error is encountered in a Python script.
5811 Invoke CODE by passing it to the Python interpreter.
5816 These allow macros to be defined, undefined, and listed
5820 Show operating system information about processes.
5823 List the inferiors currently under GDB's control.
5826 Switch focus to inferior number NUM.
5829 Detach from inferior number NUM.
5832 Kill inferior number NUM.
5836 set spu stop-on-load
5837 show spu stop-on-load
5838 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5840 set spu auto-flush-cache
5841 show spu auto-flush-cache
5842 Control whether to automatically flush the software-managed cache
5843 during Cell/B.E. debugging.
5845 set sh calling-convention
5846 show sh calling-convention
5847 Control the calling convention used when calling SH target functions.
5850 show debug timestamp
5851 Control display of timestamps with GDB debugging output.
5853 set disassemble-next-line
5854 show disassemble-next-line
5855 Control display of disassembled source lines or instructions when
5858 set remote noack-packet
5859 show remote noack-packet
5860 Set/show the use of remote protocol QStartNoAckMode packet. See above
5861 under "New remote packets."
5863 set remote query-attached-packet
5864 show remote query-attached-packet
5865 Control use of remote protocol `qAttached' (query-attached) packet.
5867 set remote read-siginfo-object
5868 show remote read-siginfo-object
5869 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5872 set remote write-siginfo-object
5873 show remote write-siginfo-object
5874 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5877 set remote reverse-continue
5878 show remote reverse-continue
5879 Control use of remote protocol 'bc' (reverse-continue) packet.
5881 set remote reverse-step
5882 show remote reverse-step
5883 Control use of remote protocol 'bs' (reverse-step) packet.
5885 set displaced-stepping
5886 show displaced-stepping
5887 Control displaced stepping mode. Displaced stepping is a way to
5888 single-step over breakpoints without removing them from the debuggee.
5889 Also known as "out-of-line single-stepping".
5892 show debug displaced
5893 Control display of debugging info for displaced stepping.
5895 maint set internal-error
5896 maint show internal-error
5897 Control what GDB does when an internal error is detected.
5899 maint set internal-warning
5900 maint show internal-warning
5901 Control what GDB does when an internal warning is detected.
5906 Use a wrapper program to launch programs for debugging.
5908 set multiple-symbols (all|ask|cancel)
5909 show multiple-symbols
5910 The value of this variable can be changed to adjust the debugger behavior
5911 when an expression or a breakpoint location contains an ambiguous symbol
5912 name (an overloaded function name, for instance).
5914 set breakpoint always-inserted
5915 show breakpoint always-inserted
5916 Keep breakpoints always inserted in the target, as opposed to inserting
5917 them when resuming the target, and removing them when the target stops.
5918 This option can improve debugger performance on slow remote targets.
5920 set arm fallback-mode (arm|thumb|auto)
5921 show arm fallback-mode
5922 set arm force-mode (arm|thumb|auto)
5924 These commands control how ARM GDB determines whether instructions
5925 are ARM or Thumb. The default for both settings is auto, which uses
5926 the current CPSR value for instructions without symbols; previous
5927 versions of GDB behaved as if "set arm fallback-mode arm".
5929 set arm unwind-secure-frames
5930 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5932 This can trigger security exceptions when unwinding exception stacks.
5934 set disable-randomization
5935 show disable-randomization
5936 Standalone programs run with the virtual address space randomization enabled
5937 by default on some platforms. This option keeps the addresses stable across
5938 multiple debugging sessions.
5942 Control whether other threads are stopped or not when some thread hits
5947 Requests that asynchronous execution is enabled in the target, if available.
5948 In this case, it's possible to resume target in the background, and interact
5949 with GDB while the target is running. "show target-async" displays the
5950 current state of asynchronous execution of the target.
5952 set target-wide-charset
5953 show target-wide-charset
5954 The target-wide-charset is the name of the character set that GDB
5955 uses when printing characters whose type is wchar_t.
5957 set tcp auto-retry (on|off)
5959 set tcp connect-timeout
5960 show tcp connect-timeout
5961 These commands allow GDB to retry failed TCP connections to a remote stub
5962 with a specified timeout period; this is useful if the stub is launched
5963 in parallel with GDB but may not be ready to accept connections immediately.
5965 set libthread-db-search-path
5966 show libthread-db-search-path
5967 Control list of directories which GDB will search for appropriate
5970 set schedule-multiple (on|off)
5971 show schedule-multiple
5972 Allow GDB to resume all threads of all processes or only threads of
5973 the current process.
5977 Use more aggressive caching for accesses to the stack. This improves
5978 performance of remote debugging (particularly backtraces) without
5979 affecting correctness.
5981 set interactive-mode (on|off|auto)
5982 show interactive-mode
5983 Control whether GDB runs in interactive mode (on) or not (off).
5984 When in interactive mode, GDB waits for the user to answer all
5985 queries. Otherwise, GDB does not wait and assumes the default
5986 answer. When set to auto (the default), GDB determines which
5987 mode to use based on the stdin settings.
5992 For program forks, this is replaced by the new more generic `info
5993 inferiors' command. To list checkpoints, you can still use the
5994 `info checkpoints' command, which was an alias for the `info forks'
5998 Replaced by the new `inferior' command. To switch between
5999 checkpoints, you can still use the `restart' command, which was an
6000 alias for the `fork' command.
6003 This is removed, since some targets don't have a notion of
6004 processes. To switch between processes, you can still use the
6005 `inferior' command using GDB's own inferior number.
6008 For program forks, this is replaced by the new more generic `kill
6009 inferior' command. To delete a checkpoint, you can still use the
6010 `delete checkpoint' command, which was an alias for the `delete
6014 For program forks, this is replaced by the new more generic `detach
6015 inferior' command. To detach a checkpoint, you can still use the
6016 `detach checkpoint' command, which was an alias for the `detach
6019 * New native configurations
6021 x86/x86_64 Darwin i[34567]86-*-darwin*
6023 x86_64 MinGW x86_64-*-mingw*
6027 Lattice Mico32 lm32-*
6028 x86 DICOS i[34567]86-*-dicos*
6029 x86_64 DICOS x86_64-*-dicos*
6032 * The GDB remote stub, gdbserver, now supports x86 Windows CE
6033 (mingw32ce) debugging.
6039 These commands were actually not implemented on any target.
6041 *** Changes in GDB 6.8
6043 * New native configurations
6045 NetBSD/hppa hppa*-*netbsd*
6046 Xtensa GNU/Linux xtensa*-*-linux*
6050 NetBSD/hppa hppa*-*-netbsd*
6051 Xtensa GNU/Linux xtensa*-*-linux*
6053 * Change in command line behavior -- corefiles vs. process ids.
6055 When the '-p NUMBER' or '--pid NUMBER' options are used, and
6056 attaching to process NUMBER fails, GDB no longer attempts to open a
6057 core file named NUMBER. Attaching to a program using the -c option
6058 is no longer supported. Instead, use the '-p' or '--pid' options.
6060 * GDB can now be built as a native debugger for debugging Windows x86
6061 (mingw32) Portable Executable (PE) programs.
6063 * Pending breakpoints no longer change their number when their address
6066 * GDB now supports breakpoints with multiple locations,
6067 including breakpoints on C++ constructors, inside C++ templates,
6068 and in inlined functions.
6070 * GDB's ability to debug optimized code has been improved. GDB more
6071 accurately identifies function bodies and lexical blocks that occupy
6072 more than one contiguous range of addresses.
6074 * Target descriptions can now describe registers for PowerPC.
6076 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
6077 registers on PowerPC targets.
6079 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
6080 targets even when the libthread_db library is not available.
6082 * The GDB remote stub, gdbserver, now supports the new file transfer
6083 commands (remote put, remote get, and remote delete).
6085 * The GDB remote stub, gdbserver, now supports run and attach in
6086 extended-remote mode.
6088 * hppa*64*-*-hpux11* target broken
6089 The debugger is unable to start a program and fails with the following
6090 error: "Error trying to get information about dynamic linker".
6091 The gdb-6.7 release is also affected.
6093 * GDB now supports the --enable-targets= configure option to allow
6094 building a single GDB executable that supports multiple remote
6095 target architectures.
6097 * GDB now supports debugging C and C++ programs which use the
6098 Decimal Floating Point extension. In addition, the PowerPC target
6099 now has a set of pseudo-registers to inspect decimal float values
6100 stored in two consecutive float registers.
6102 * The -break-insert MI command can optionally create pending
6105 * Improved support for debugging Ada
6106 Many improvements to the Ada language support have been made. These
6108 - Better support for Ada2005 interface types
6109 - Improved handling of arrays and slices in general
6110 - Better support for Taft-amendment types
6111 - The '{type} ADDRESS' expression is now allowed on the left hand-side
6113 - Improved command completion in Ada
6116 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
6121 set print frame-arguments (all|scalars|none)
6122 show print frame-arguments
6123 The value of this variable can be changed to control which argument
6124 values should be printed by the debugger when displaying a frame.
6129 Transfer files to and from a remote target, and delete remote files.
6136 Transfer files to and from a remote target, and delete remote files.
6138 * New remote packets
6145 Open, close, read, write, and delete files on the remote system.
6148 Attach to an existing process on the remote system, in extended-remote
6152 Run a new process on the remote system, in extended-remote mode.
6154 *** Changes in GDB 6.7
6156 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
6157 bfd, libiberty and opcodes, as revealed by static analysis donated by
6158 Coverity, Inc. (http://scan.coverity.com).
6160 * When looking up multiply-defined global symbols, GDB will now prefer the
6161 symbol definition in the current shared library if it was built using the
6162 -Bsymbolic linker option.
6164 * When the Text User Interface (TUI) is not configured, GDB will now
6165 recognize the -tui command-line option and print a message that the TUI
6168 * The GDB remote stub, gdbserver, now has lower overhead for high
6169 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
6171 * GDB for MIPS targets now autodetects whether a remote target provides
6172 32-bit or 64-bit register values.
6174 * Support for C++ member pointers has been improved.
6176 * GDB now understands XML target descriptions, which specify the
6177 target's overall architecture. GDB can read a description from
6178 a local file or over the remote serial protocol.
6180 * Vectors of single-byte data use a new integer type which is not
6181 automatically displayed as character or string data.
6183 * The /s format now works with the print command. It displays
6184 arrays of single-byte integers and pointers to single-byte integers
6187 * Target descriptions can now describe target-specific registers,
6188 for architectures which have implemented the support (currently
6189 only ARM, M68K, and MIPS).
6191 * GDB and the GDB remote stub, gdbserver, now support the XScale
6194 * The GDB remote stub, gdbserver, has been updated to support
6195 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6196 has been rewritten to use the standard GDB remote protocol.
6198 * GDB can now step into C++ functions which are called through thunks.
6200 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6202 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6203 layout. It also supports a TextSeg= and DataSeg= response when only
6204 segment base addresses (rather than offsets) are available.
6206 * The /i format now outputs any trailing branch delay slot instructions
6207 immediately following the last instruction within the count specified.
6209 * The GDB remote protocol "T" stop reply packet now supports a
6210 "library" response. Combined with the new "qXfer:libraries:read"
6211 packet, this response allows GDB to debug shared libraries on targets
6212 where the operating system manages the list of loaded libraries (e.g.
6213 Windows and SymbianOS).
6215 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6216 (DLLs) on Windows and Windows CE targets.
6218 * GDB now supports a faster verification that a .debug file matches its binary
6219 according to its build-id signature, if the signature is present.
6225 Enable or disable hardware flow control (RTS/CTS) on the serial port
6226 when debugging using remote targets.
6228 set mem inaccessible-by-default
6229 show mem inaccessible-by-default
6230 If the target supplies a memory map, for instance via the remote
6231 protocol's "qXfer:memory-map:read" packet, setting this variable
6232 prevents GDB from accessing memory outside the memory map. This
6233 is useful for targets with memory mapped registers or which react
6234 badly to accesses of unmapped address space.
6236 set breakpoint auto-hw
6237 show breakpoint auto-hw
6238 If the target supplies a memory map, for instance via the remote
6239 protocol's "qXfer:memory-map:read" packet, setting this variable
6240 lets GDB use hardware breakpoints automatically for memory regions
6241 where it can not use software breakpoints. This covers both the
6242 "break" command and internal breakpoints used for other commands
6243 including "next" and "finish".
6246 catch exception unhandled
6247 Stop the program execution when Ada exceptions are raised.
6250 Stop the program execution when an Ada assertion failed.
6254 Set an alternate system root for target files. This is a more
6255 general version of "set solib-absolute-prefix", which is now
6256 an alias to "set sysroot".
6259 Provide extended SPU facility status information. This set of
6260 commands is available only when debugging the Cell/B.E. SPU
6263 * New native configurations
6265 OpenBSD/sh sh*-*openbsd*
6268 unset tdesc filename
6270 Use the specified local file as an XML target description, and do
6271 not query the target for its built-in description.
6275 OpenBSD/sh sh*-*-openbsd*
6276 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
6277 Toshiba Media Processor mep-elf
6279 * New remote packets
6282 Ignore the specified signals; pass them directly to the debugged program
6283 without stopping other threads or reporting them to GDB.
6285 qXfer:features:read:
6286 Read an XML target description from the target, which describes its
6291 Read or write contents of an spufs file on the target system. These
6292 packets are available only on the Cell/B.E. SPU architecture.
6294 qXfer:libraries:read:
6295 Report the loaded shared libraries. Combined with new "T" packet
6296 response, this packet allows GDB to debug shared libraries on
6297 targets where the operating system manages the list of loaded
6298 libraries (e.g. Windows and SymbianOS).
6302 Support for these obsolete configurations has been removed.
6310 i[34567]86-*-lynxos*
6311 i[34567]86-*-netware*
6312 i[34567]86-*-sco3.2v5*
6313 i[34567]86-*-sco3.2v4*
6315 i[34567]86-*-sysv4.2*
6318 i[34567]86-*-unixware2*
6319 i[34567]86-*-unixware*
6328 * Other removed features
6335 Various m68k-only ROM monitors.
6342 Various Renesas ROM monitors and debugging interfaces for SH and
6347 Support for a Macraigor serial interface to on-chip debugging.
6348 GDB does not directly support the newer parallel or USB
6353 A debug information format. The predecessor to DWARF 2 and
6354 DWARF 3, which are still supported.
6356 Support for the HP aCC compiler on HP-UX/PA-RISC
6358 SOM-encapsulated symbolic debugging information, automatic
6359 invocation of pxdb, and the aCC custom C++ ABI. This does not
6360 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6361 with aCC can still be debugged on an assembly level.
6363 MIPS ".pdr" sections
6365 A MIPS-specific format used to describe stack frame layout
6366 in debugging information.
6370 GDB could work with an older version of Guile to debug
6371 the interpreter and Scheme programs running in it.
6373 set mips stack-arg-size
6374 set mips saved-gpreg-size
6376 Use "set mips abi" to control parameter passing for MIPS.
6378 *** Changes in GDB 6.6
6383 Cell Broadband Engine SPU spu-elf
6385 * GDB can now be configured as a cross-debugger targeting native Windows
6386 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6387 running on a Windows system over TCP/IP to debug Windows programs.
6389 * The GDB remote stub, gdbserver, has been updated to support Windows and
6390 Cygwin debugging. Both single-threaded and multi-threaded programs are
6393 * The "set trust-readonly-sections" command works again. This command was
6394 broken in GDB 6.3, 6.4, and 6.5.
6396 * The "load" command now supports writing to flash memory, if the remote
6397 stub provides the required support.
6399 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
6400 longer requires symbolic debug information (e.g. DWARF-2).
6405 unset substitute-path
6406 show substitute-path
6407 Manage a list of substitution rules that GDB uses to rewrite the name
6408 of the directories where the sources are located. This can be useful
6409 for instance when the sources were moved to a different location
6410 between compilation and debugging.
6414 Print each CLI command as it is executed. Each command is prefixed with
6415 a number of `+' symbols representing the nesting depth.
6416 The source command now has a `-v' option to enable the same feature.
6420 The ARM Demon monitor support (RDP protocol, "target rdp").
6422 Kernel Object Display, an embedded debugging feature which only worked with
6423 an obsolete version of Cisco IOS.
6425 The 'set download-write-size' and 'show download-write-size' commands.
6427 * New remote packets
6430 Tell a stub about GDB client features, and request remote target features.
6431 The first feature implemented is PacketSize, which allows the target to
6432 specify the size of packets it can handle - to minimize the number of
6433 packets required and improve performance when connected to a remote
6437 Fetch an OS auxilliary vector from the remote stub. This packet is a
6438 more efficient replacement for qPart:auxv:read.
6440 qXfer:memory-map:read:
6441 Fetch a memory map from the remote stub, including information about
6442 RAM, ROM, and flash memory devices.
6447 Erase and program a flash memory device.
6449 * Removed remote packets
6452 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
6453 used it, and only gdbserver implemented it.
6455 *** Changes in GDB 6.5
6459 Renesas M32C/M16C m32c-elf
6461 Morpho Technologies ms1 ms1-elf
6465 init-if-undefined Initialize a convenience variable, but
6466 only if it doesn't already have a value.
6468 The following commands are presently only implemented for native GNU/Linux:
6470 checkpoint Save a snapshot of the program state.
6472 restart <n> Return the program state to a
6473 previously saved state.
6475 info checkpoints List currently saved checkpoints.
6477 delete-checkpoint <n> Delete a previously saved checkpoint.
6479 set|show detach-on-fork Tell gdb whether to detach from a newly
6480 forked process, or to keep debugging it.
6482 info forks List forks of the user program that
6483 are available to be debugged.
6485 fork <n> Switch to debugging one of several
6486 forks of the user program that are
6487 available to be debugged.
6489 delete-fork <n> Delete a fork from the list of forks
6490 that are available to be debugged (and
6491 kill the forked process).
6493 detach-fork <n> Delete a fork from the list of forks
6494 that are available to be debugged (and
6495 allow the process to continue).
6499 Morpho Technologies ms2 ms1-elf
6501 * Improved Windows host support
6503 GDB now builds as a cross debugger hosted on i686-mingw32, including
6504 native console support, and remote communications using either
6505 network sockets or serial ports.
6507 * Improved Modula-2 language support
6509 GDB can now print most types in the Modula-2 syntax. This includes:
6510 basic types, set types, record types, enumerated types, range types,
6511 pointer types and ARRAY types. Procedure var parameters are correctly
6512 printed and hexadecimal addresses and character constants are also
6513 written in the Modula-2 syntax. Best results can be obtained by using
6514 GNU Modula-2 together with the -gdwarf-2 command line option.
6518 The ARM rdi-share module.
6520 The Netware NLM debug server.
6522 *** Changes in GDB 6.4
6524 * New native configurations
6526 OpenBSD/arm arm*-*-openbsd*
6527 OpenBSD/mips64 mips64-*-openbsd*
6531 Morpho Technologies ms1 ms1-elf
6533 * New command line options
6535 --batch-silent As for --batch, but totally silent.
6536 --return-child-result The debugger will exist with the same value
6537 the child (debugged) program exited with.
6538 --eval-command COMMAND, -ex COMMAND
6539 Execute a single GDB CLI command. This may be
6540 specified multiple times and in conjunction
6541 with the --command (-x) option.
6543 * Deprecated commands removed
6545 The following commands, that were deprecated in 2000, have been
6549 set|show arm disassembly-flavor set|show arm disassembler
6550 othernames set arm disassembler
6551 set|show remotedebug set|show debug remote
6552 set|show archdebug set|show debug arch
6553 set|show eventdebug set|show debug event
6556 * New BSD user-level threads support
6558 It is now possible to debug programs using the user-level threads
6559 library on OpenBSD and FreeBSD. Currently supported (target)
6562 FreeBSD/amd64 x86_64-*-freebsd*
6563 FreeBSD/i386 i386-*-freebsd*
6564 OpenBSD/i386 i386-*-openbsd*
6566 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6567 are not yet supported.
6569 * New support for Matsushita MN10300 w/sim added
6570 (Work in progress). mn10300-elf.
6572 * REMOVED configurations and files
6574 VxWorks and the XDR protocol *-*-vxworks
6575 Motorola MCORE mcore-*-*
6576 National Semiconductor NS32000 ns32k-*-*
6578 * New "set print array-indexes" command
6580 After turning this setting "on", GDB prints the index of each element
6581 when displaying arrays. The default is "off" to preserve the previous
6584 * VAX floating point support
6586 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6588 * User-defined command support
6590 In addition to using $arg0..$arg9 for argument passing, it is now possible
6591 to use $argc to determine now many arguments have been passed. See the
6592 section on user-defined commands in the user manual for more information.
6594 *** Changes in GDB 6.3:
6596 * New command line option
6598 GDB now accepts -l followed by a number to set the timeout for remote
6601 * GDB works with GCC -feliminate-dwarf2-dups
6603 GDB now supports a more compact representation of DWARF-2 debug
6604 information using DW_FORM_ref_addr references. These are produced
6605 by GCC with the option -feliminate-dwarf2-dups and also by some
6606 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6607 to use -feliminate-dwarf2-dups.
6609 * Internationalization
6611 When supported by the host system, GDB will be built with
6612 internationalization (libintl). The task of marking up the sources is
6613 continued, we're looking forward to our first translation.
6617 Initial support for debugging programs compiled with the GNAT
6618 implementation of the Ada programming language has been integrated
6619 into GDB. In this release, support is limited to expression evaluation.
6621 * New native configurations
6623 GNU/Linux/m32r m32r-*-linux-gnu
6627 GDB's remote protocol now includes support for the 'p' packet. This
6628 packet is used to fetch individual registers from a remote inferior.
6630 * END-OF-LIFE registers[] compatibility module
6632 GDB's internal register infrastructure has been completely rewritten.
6633 The new infrastructure making possible the implementation of key new
6634 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6637 GDB 6.3 will be the last release to include the registers[]
6638 compatibility module that allowed out-of-date configurations to
6639 continue to work. This change directly impacts the following
6649 powerpc bdm protocol
6651 Unless there is activity to revive these configurations, they will be
6652 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6654 * OBSOLETE configurations and files
6656 Configurations that have been declared obsolete in this release have
6657 been commented out. Unless there is activity to revive these
6658 configurations, the next release of GDB will have their sources
6659 permanently REMOVED.
6668 *** Changes in GDB 6.2.1:
6670 * MIPS `break main; run' gave an heuristic-fence-post warning
6672 When attempting to run even a simple program, a warning about
6673 heuristic-fence-post being hit would be reported. This problem has
6676 * MIPS IRIX 'long double' crashed GDB
6678 When examining a long double variable, GDB would get a segmentation
6679 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6680 IRIX long double values).
6684 A bug in the VAX stack code was causing problems with the "next"
6685 command. This problem has been fixed.
6687 *** Changes in GDB 6.2:
6689 * Fix for ``many threads''
6691 On GNU/Linux systems that use the NPTL threads library, a program
6692 rapidly creating and deleting threads would confuse GDB leading to the
6695 ptrace: No such process.
6696 thread_db_get_info: cannot get thread info: generic error
6698 This problem has been fixed.
6700 * "-async" and "-noasync" options removed.
6702 Support for the broken "-noasync" option has been removed (it caused
6705 * New ``start'' command.
6707 This command runs the program until the beginning of the main procedure.
6709 * New BSD Kernel Data Access Library (libkvm) interface
6711 Using ``target kvm'' it is now possible to debug kernel core dumps and
6712 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6713 platforms. Currently supported (native-only) configurations are:
6715 FreeBSD/amd64 x86_64-*-freebsd*
6716 FreeBSD/i386 i?86-*-freebsd*
6717 NetBSD/i386 i?86-*-netbsd*
6718 NetBSD/m68k m68*-*-netbsd*
6719 NetBSD/sparc sparc-*-netbsd*
6720 OpenBSD/amd64 x86_64-*-openbsd*
6721 OpenBSD/i386 i?86-*-openbsd*
6722 OpenBSD/m68k m68*-openbsd*
6723 OpenBSD/sparc sparc-*-openbsd*
6725 * Signal trampoline code overhauled
6727 Many generic problems with GDB's signal handling code have been fixed.
6728 These include: backtraces through non-contiguous stacks; recognition
6729 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6730 call; backtrace through a signal trampoline; step into and out of
6731 signal handlers; and single-stepping in the signal trampoline.
6733 Please note that kernel bugs are a limiting factor here. These
6734 features have been shown to work on an s390 GNU/Linux system that
6735 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6737 * Cygwin support for DWARF 2 added.
6739 * New native configurations
6741 GNU/Linux/hppa hppa*-*-linux*
6742 OpenBSD/hppa hppa*-*-openbsd*
6743 OpenBSD/m68k m68*-*-openbsd*
6744 OpenBSD/m88k m88*-*-openbsd*
6745 OpenBSD/powerpc powerpc-*-openbsd*
6746 NetBSD/vax vax-*-netbsd*
6747 OpenBSD/vax vax-*-openbsd*
6749 * END-OF-LIFE frame compatibility module
6751 GDB's internal frame infrastructure has been completely rewritten.
6752 The new infrastructure making it possible to support key new features
6753 including DWARF 2 Call Frame Information. To aid in the task of
6754 migrating old configurations to this new infrastructure, a
6755 compatibility module, that allowed old configurations to continue to
6756 work, was also included.
6758 GDB 6.2 will be the last release to include this frame compatibility
6759 module. This change directly impacts the following configurations:
6769 Unless there is activity to revive these configurations, they will be
6770 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6772 * REMOVED configurations and files
6774 Sun 3, running SunOS 3 m68*-*-sunos3*
6775 Sun 3, running SunOS 4 m68*-*-sunos4*
6776 Sun 2, running SunOS 3 m68000-*-sunos3*
6777 Sun 2, running SunOS 4 m68000-*-sunos4*
6778 Motorola 680x0 running LynxOS m68*-*-lynxos*
6779 AT&T 3b1/Unix pc m68*-att-*
6780 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6781 decstation mips-dec-* mips-little-*
6782 riscos mips-*-riscos* mips-*-sysv*
6783 sonymips mips-sony-*
6784 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6786 *** Changes in GDB 6.1.1:
6788 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6790 The TUI (Text-mode User Interface) is now built as part of a default
6791 GDB configuration. It is enabled by either selecting the TUI with the
6792 command line option "-i=tui" or by running the separate "gdbtui"
6793 program. For more information on the TUI, see the manual "Debugging
6796 * Pending breakpoint support (also included in GDB 6.1)
6798 Support has been added to allow you to specify breakpoints in shared
6799 libraries that have not yet been loaded. If a breakpoint location
6800 cannot be found, and the "breakpoint pending" option is set to auto,
6801 GDB queries you if you wish to make the breakpoint pending on a future
6802 shared-library load. If and when GDB resolves the breakpoint symbol,
6803 the pending breakpoint is removed as one or more regular breakpoints
6806 Pending breakpoints are very useful for GCJ Java debugging.
6808 * Fixed ISO-C build problems
6810 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6811 non ISO-C code that stopped them being built using a more strict ISO-C
6812 compiler (e.g., IBM's C compiler).
6814 * Fixed build problem on IRIX 5
6816 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6817 wasn't able to compile compile on an IRIX 5 system.
6819 * Added execute permission to gdb/gdbserver/configure
6821 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6822 permission. This bug would cause configure to fail on a number of
6823 systems (Solaris, IRIX). Ref: server/519.
6825 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6827 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6828 has been updated to use constant array sizes.
6830 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6832 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6833 its generated DWARF Call Frame Info. This encoding was causing GDB to
6834 panic, that panic has been fixed. Ref: gdb/1628.
6836 * Fixed a problem when examining parameters in shared library code.
6838 When examining parameters in optimized shared library code generated
6839 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6840 not available''. GDB now correctly displays the variable's value.
6842 *** Changes in GDB 6.1:
6844 * Removed --with-mmalloc
6846 Support for the mmalloc memory manager has been removed, as it
6847 conflicted with the internal gdb byte cache.
6849 * Changes in AMD64 configurations
6851 The AMD64 target now includes the %cs and %ss registers. As a result
6852 the AMD64 remote protocol has changed; this affects the floating-point
6853 and SSE registers. If you rely on those registers for your debugging,
6854 you should upgrade gdbserver on the remote side.
6856 * Revised SPARC target
6858 The SPARC target has been completely revised, incorporating the
6859 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6860 support for LynxOS and SunOS 4 has been dropped. Calling functions
6861 from within GDB on operating systems with a non-executable stack
6862 (Solaris, OpenBSD) now works.
6866 GDB has a new C++ demangler which does a better job on the mangled
6867 names generated by current versions of g++. It also runs faster, so
6868 with this and other changes gdb should now start faster on large C++
6871 * DWARF 2 Location Expressions
6873 GDB support for location expressions has been extended to support function
6874 arguments and frame bases. Older versions of GDB could crash when they
6877 * C++ nested types and namespaces
6879 GDB's support for nested types and namespaces in C++ has been
6880 improved, especially if you use the DWARF 2 debugging format. (This
6881 is the default for recent versions of GCC on most platforms.)
6882 Specifically, if you have a class "Inner" defined within a class or
6883 namespace "Outer", then GDB realizes that the class's name is
6884 "Outer::Inner", not simply "Inner". This should greatly reduce the
6885 frequency of complaints about not finding RTTI symbols. In addition,
6886 if you are stopped at inside of a function defined within a namespace,
6887 GDB modifies its name lookup accordingly.
6889 * New native configurations
6891 NetBSD/amd64 x86_64-*-netbsd*
6892 OpenBSD/amd64 x86_64-*-openbsd*
6893 OpenBSD/alpha alpha*-*-openbsd*
6894 OpenBSD/sparc sparc-*-openbsd*
6895 OpenBSD/sparc64 sparc64-*-openbsd*
6897 * New debugging protocols
6899 M32R with SDI protocol m32r-*-elf*
6901 * "set prompt-escape-char" command deleted.
6903 The command "set prompt-escape-char" has been deleted. This command,
6904 and its very obscure effect on GDB's prompt, was never documented,
6905 tested, nor mentioned in the NEWS file.
6907 * OBSOLETE configurations and files
6909 Configurations that have been declared obsolete in this release have
6910 been commented out. Unless there is activity to revive these
6911 configurations, the next release of GDB will have their sources
6912 permanently REMOVED.
6914 Sun 3, running SunOS 3 m68*-*-sunos3*
6915 Sun 3, running SunOS 4 m68*-*-sunos4*
6916 Sun 2, running SunOS 3 m68000-*-sunos3*
6917 Sun 2, running SunOS 4 m68000-*-sunos4*
6918 Motorola 680x0 running LynxOS m68*-*-lynxos*
6919 AT&T 3b1/Unix pc m68*-att-*
6920 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6921 decstation mips-dec-* mips-little-*
6922 riscos mips-*-riscos* mips-*-sysv*
6923 sonymips mips-sony-*
6924 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6926 * REMOVED configurations and files
6928 SGI Irix-4.x mips-sgi-irix4 or iris4
6929 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6930 Z8000 simulator z8k-zilog-none or z8ksim
6931 Matsushita MN10200 w/simulator mn10200-*-*
6932 H8/500 simulator h8500-hitachi-hms or h8500hms
6933 HP/PA running BSD hppa*-*-bsd*
6934 HP/PA running OSF/1 hppa*-*-osf*
6935 HP/PA Pro target hppa*-*-pro*
6936 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6937 386BSD i[3456]86-*-bsd*
6938 Sequent family i[3456]86-sequent-sysv4*
6939 i[3456]86-sequent-sysv*
6940 i[3456]86-sequent-bsd*
6941 SPARC running LynxOS sparc-*-lynxos*
6942 SPARC running SunOS 4 sparc-*-sunos4*
6943 Tsqware Sparclet sparclet-*-*
6944 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6946 *** Changes in GDB 6.0:
6950 Support for debugging the Objective-C programming language has been
6951 integrated into GDB.
6953 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6955 DWARF 2's Call Frame Information makes available compiler generated
6956 information that more exactly describes the program's run-time stack.
6957 By using this information, GDB is able to provide more robust stack
6960 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6961 have been updated to use a new backtrace mechanism which includes
6962 DWARF 2 CFI support.
6966 GDB's remote protocol has been extended to include support for hosted
6967 file I/O (where the remote target uses GDB's file system). See GDB's
6968 remote protocol documentation for details.
6970 * All targets using the new architecture framework.
6972 All of GDB's targets have been updated to use the new internal
6973 architecture framework. The way is now open for future GDB releases
6974 to include cross-architecture native debugging support (i386 on amd64,
6977 * GNU/Linux's Thread Local Storage (TLS)
6979 GDB now includes support for for the GNU/Linux implementation of
6980 per-thread variables.
6982 * GNU/Linux's Native POSIX Thread Library (NPTL)
6984 GDB's thread code has been updated to work with either the new
6985 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6987 * Separate debug info.
6989 GDB, in conjunction with BINUTILS, now supports a mechanism for
6990 automatically loading debug information from a separate file. Instead
6991 of shipping full debug and non-debug versions of system libraries,
6992 system integrators can now instead ship just the stripped libraries
6993 and optional debug files.
6995 * DWARF 2 Location Expressions
6997 DWARF 2 Location Expressions allow the compiler to more completely
6998 describe the location of variables (even in optimized code) to the
7001 GDB now includes preliminary support for location expressions (support
7002 for DW_OP_piece is still missing).
7006 A number of long standing bugs that caused GDB to die while starting a
7007 Java application have been fixed. GDB's Java support is now
7008 considered "useable".
7010 * GNU/Linux support for fork, vfork, and exec.
7012 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
7013 commands are now implemented for GNU/Linux. They require a 2.5.x or later
7016 * GDB supports logging output to a file
7018 There are two new commands, "set logging" and "show logging", which can be
7019 used to capture GDB's output to a file.
7021 * The meaning of "detach" has changed for gdbserver
7023 The "detach" command will now resume the application, as documented. To
7024 disconnect from gdbserver and leave it stopped, use the new "disconnect"
7027 * d10v, m68hc11 `regs' command deprecated
7029 The `info registers' command has been updated so that it displays the
7030 registers using a format identical to the old `regs' command.
7034 A new command, "maint set profile on/off", has been added. This command can
7035 be used to enable or disable profiling while running GDB, to profile a
7036 session or a set of commands. In addition there is a new configure switch,
7037 "--enable-profiling", which will cause GDB to be compiled with profiling
7038 data, for more informative profiling results.
7040 * Default MI syntax changed to "mi2".
7042 The default MI (machine interface) syntax, enabled by the command line
7043 option "-i=mi", has been changed to "mi2". The previous MI syntax,
7044 "mi1", can be enabled by specifying the option "-i=mi1".
7046 Support for the original "mi0" syntax (included in GDB 5.0) has been
7049 Fix for gdb/192: removed extraneous space when displaying frame level.
7050 Fix for gdb/672: update changelist is now output in mi list format.
7051 Fix for gdb/702: a -var-assign that updates the value now shows up
7052 in a subsequent -var-update.
7054 * New native configurations.
7056 FreeBSD/amd64 x86_64-*-freebsd*
7058 * Multi-arched targets.
7060 HP/PA HPUX11 hppa*-*-hpux*
7061 Renesas M32R/D w/simulator m32r-*-elf*
7063 * OBSOLETE configurations and files
7065 Configurations that have been declared obsolete in this release have
7066 been commented out. Unless there is activity to revive these
7067 configurations, the next release of GDB will have their sources
7068 permanently REMOVED.
7070 Z8000 simulator z8k-zilog-none or z8ksim
7071 Matsushita MN10200 w/simulator mn10200-*-*
7072 H8/500 simulator h8500-hitachi-hms or h8500hms
7073 HP/PA running BSD hppa*-*-bsd*
7074 HP/PA running OSF/1 hppa*-*-osf*
7075 HP/PA Pro target hppa*-*-pro*
7076 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
7077 Sequent family i[3456]86-sequent-sysv4*
7078 i[3456]86-sequent-sysv*
7079 i[3456]86-sequent-bsd*
7080 Tsqware Sparclet sparclet-*-*
7081 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7083 * REMOVED configurations and files
7086 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7087 IBM AIX PS/2 i[3456]86-*-aix
7088 i386 running Mach 3.0 i[3456]86-*-mach3*
7089 i386 running Mach i[3456]86-*-mach*
7090 i386 running OSF/1 i[3456]86-*osf1mk*
7091 HP/Apollo 68k Family m68*-apollo*-sysv*,
7093 m68*-hp-bsd*, m68*-hp-hpux*
7094 Argonaut Risc Chip (ARC) arc-*-*
7095 Mitsubishi D30V d30v-*-*
7096 Fujitsu FR30 fr30-*-elf*
7097 OS/9000 i[34]86-*-os9k
7098 I960 with MON960 i960-*-coff
7100 * MIPS $fp behavior changed
7102 The convenience variable $fp, for the MIPS, now consistently returns
7103 the address of the current frame's base. Previously, depending on the
7104 context, $fp could refer to either $sp or the current frame's base
7105 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
7106 The GNU Source-Level Debugger''.
7108 *** Changes in GDB 5.3:
7110 * GNU/Linux shared library multi-threaded performance improved.
7112 When debugging a multi-threaded application on GNU/Linux, GDB now uses
7113 `/proc', in preference to `ptrace' for memory reads. This may result
7114 in an improvement in the start-up time of multi-threaded, shared
7115 library applications when run under GDB. One GDB user writes: ``loads
7116 shared libs like mad''.
7118 * ``gdbserver'' now supports multi-threaded applications on some targets
7120 Support for debugging multi-threaded applications which use
7121 the GNU/Linux LinuxThreads package has been added for
7122 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
7123 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
7125 * GDB now supports C/C++ preprocessor macros.
7127 GDB now expands preprocessor macro invocations in C/C++ expressions,
7128 and provides various commands for showing macro definitions and how
7131 The new command `macro expand EXPRESSION' expands any macro
7132 invocations in expression, and shows the result.
7134 The new command `show macro MACRO-NAME' shows the definition of the
7135 macro named MACRO-NAME, and where it was defined.
7137 Most compilers don't include information about macros in the debugging
7138 information by default. In GCC 3.1, for example, you need to compile
7139 your program with the options `-gdwarf-2 -g3'. If the macro
7140 information is present in the executable, GDB will read it.
7142 * Multi-arched targets.
7144 DEC Alpha (partial) alpha*-*-*
7145 DEC VAX (partial) vax-*-*
7147 National Semiconductor NS32000 (partial) ns32k-*-*
7148 Motorola 68000 (partial) m68k-*-*
7149 Motorola MCORE mcore-*-*
7153 Fujitsu FRV architecture added by Red Hat frv*-*-*
7156 * New native configurations
7158 Alpha NetBSD alpha*-*-netbsd*
7159 SH NetBSD sh*-*-netbsdelf*
7160 MIPS NetBSD mips*-*-netbsd*
7161 UltraSPARC NetBSD sparc64-*-netbsd*
7163 * OBSOLETE configurations and files
7165 Configurations that have been declared obsolete in this release have
7166 been commented out. Unless there is activity to revive these
7167 configurations, the next release of GDB will have their sources
7168 permanently REMOVED.
7170 Mitsubishi D30V d30v-*-*
7171 OS/9000 i[34]86-*-os9k
7172 IBM AIX PS/2 i[3456]86-*-aix
7173 Fujitsu FR30 fr30-*-elf*
7174 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7175 Argonaut Risc Chip (ARC) arc-*-*
7176 i386 running Mach 3.0 i[3456]86-*-mach3*
7177 i386 running Mach i[3456]86-*-mach*
7178 i386 running OSF/1 i[3456]86-*osf1mk*
7179 HP/Apollo 68k Family m68*-apollo*-sysv*,
7181 m68*-hp-bsd*, m68*-hp-hpux*
7182 I960 with MON960 i960-*-coff
7184 * OBSOLETE languages
7186 CHILL, a Pascal like language used by telecommunications companies.
7188 * REMOVED configurations and files
7190 AMD 29k family via UDI a29k-amd-udi, udi29k
7191 A29K VxWorks a29k-*-vxworks
7192 AMD 29000 embedded, using EBMON a29k-none-none
7193 AMD 29000 embedded with COFF a29k-none-coff
7194 AMD 29000 embedded with a.out a29k-none-aout
7196 testsuite/gdb.hp/gdb.threads-hp/ directory
7198 * New command "set max-user-call-depth <nnn>"
7200 This command allows the user to limit the call depth of user-defined
7201 commands. The default is 1024.
7203 * Changes in FreeBSD/i386 native debugging.
7205 Support for the "generate-core-file" has been added.
7207 * New commands "dump", "append", and "restore".
7209 These commands allow data to be copied from target memory
7210 to a bfd-format or binary file (dump and append), and back
7211 from a file into memory (restore).
7213 * Improved "next/step" support on multi-processor Alpha Tru64.
7215 The previous single-step mechanism could cause unpredictable problems,
7216 including the random appearance of SIGSEGV or SIGTRAP signals. The use
7217 of a software single-step mechanism prevents this.
7219 *** Changes in GDB 5.2.1:
7227 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
7228 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
7229 Fix, by Joel Brobecker imported from mainline.
7231 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
7232 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
7233 Fix, by Fred Fish, imported from mainline.
7235 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
7236 Surprisingly enough, it works now.
7237 By Michal Ludvig, imported from mainline.
7239 i386 hardware watchpoint support:
7240 avoid misses on second run for some targets.
7241 By Pierre Muller, imported from mainline.
7243 *** Changes in GDB 5.2:
7245 * New command "set trust-readonly-sections on[off]".
7247 This command is a hint that tells gdb that read-only sections
7248 really are read-only (ie. that their contents will not change).
7249 In this mode, gdb will go to the object file rather than the
7250 target to read memory from read-only sections (such as ".text").
7251 This can be a significant performance improvement on some
7252 (notably embedded) targets.
7254 * New command "generate-core-file" (or "gcore").
7256 This new gdb command allows the user to drop a core file of the child
7257 process state at any time. So far it's been implemented only for
7258 GNU/Linux and Solaris, but should be relatively easily ported to other
7259 hosts. Argument is core file name (defaults to core.<pid>).
7261 * New command line option
7263 GDB now accepts --pid or -p followed by a process id.
7265 * Change in command line behavior -- corefiles vs. process ids.
7267 There is a subtle behavior in the way in which GDB handles
7268 command line arguments. The first non-flag argument is always
7269 a program to debug, but the second non-flag argument may either
7270 be a corefile or a process id. Previously, GDB would attempt to
7271 open the second argument as a corefile, and if that failed, would
7272 issue a superfluous error message and then attempt to attach it as
7273 a process. Now, if the second argument begins with a non-digit,
7274 it will be treated as a corefile. If it begins with a digit,
7275 GDB will attempt to attach it as a process, and if no such process
7276 is found, will then attempt to open it as a corefile.
7278 * Changes in ARM configurations.
7280 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
7281 configuration is fully multi-arch.
7283 * New native configurations
7285 ARM NetBSD arm*-*-netbsd*
7286 x86 OpenBSD i[3456]86-*-openbsd*
7287 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7288 Sparc64 running FreeBSD sparc64-*-freebsd*
7292 Sanyo XStormy16 xstormy16-elf
7294 * OBSOLETE configurations and files
7296 Configurations that have been declared obsolete in this release have
7297 been commented out. Unless there is activity to revive these
7298 configurations, the next release of GDB will have their sources
7299 permanently REMOVED.
7301 AMD 29k family via UDI a29k-amd-udi, udi29k
7302 A29K VxWorks a29k-*-vxworks
7303 AMD 29000 embedded, using EBMON a29k-none-none
7304 AMD 29000 embedded with COFF a29k-none-coff
7305 AMD 29000 embedded with a.out a29k-none-aout
7307 testsuite/gdb.hp/gdb.threads-hp/ directory
7309 * REMOVED configurations and files
7311 TI TMS320C80 tic80-*-*
7313 PowerPC Solaris powerpcle-*-solaris*
7314 PowerPC Windows NT powerpcle-*-cygwin32
7315 PowerPC Netware powerpc-*-netware*
7316 Harris/CXUX m88k m88*-harris-cxux*
7317 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7318 ns32k-utek-sysv* ns32k-utek-*
7319 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7320 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7321 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7322 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7323 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7325 * Changes to command line processing
7327 The new `--args' feature can be used to specify command-line arguments
7328 for the inferior from gdb's command line.
7330 * Changes to key bindings
7332 There is a new `operate-and-get-next' function bound to `C-o'.
7334 *** Changes in GDB 5.1.1
7336 Fix compile problem on DJGPP.
7338 Fix a problem with floating-point registers on the i386 being
7341 Fix to stop GDB crashing on .debug_str debug info.
7343 Numerous documentation fixes.
7345 Numerous testsuite fixes.
7347 *** Changes in GDB 5.1:
7349 * New native configurations
7351 Alpha FreeBSD alpha*-*-freebsd*
7352 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7353 MIPS GNU/Linux mips*-*-linux*
7354 MIPS SGI Irix 6.x mips*-sgi-irix6*
7355 ia64 AIX ia64-*-aix*
7356 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7360 Motorola 68HC11 and 68HC12 m68hc11-elf
7362 UltraSparc running GNU/Linux sparc64-*-linux*
7364 * OBSOLETE configurations and files
7366 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7367 Harris/CXUX m88k m88*-harris-cxux*
7368 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7369 ns32k-utek-sysv* ns32k-utek-*
7370 TI TMS320C80 tic80-*-*
7372 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7373 PowerPC Solaris powerpcle-*-solaris*
7374 PowerPC Windows NT powerpcle-*-cygwin32
7375 PowerPC Netware powerpc-*-netware*
7376 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7377 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7378 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7379 Apple Macintosh (MPW) host N/A
7381 stuff.c (Program to stuff files into a specially prepared space in kdb)
7382 kdb-start.c (Main loop for the standalone kernel debugger)
7384 Configurations that have been declared obsolete in this release have
7385 been commented out. Unless there is activity to revive these
7386 configurations, the next release of GDB will have their sources
7387 permanently REMOVED.
7389 * REMOVED configurations and files
7391 Altos 3068 m68*-altos-*
7392 Convex c1-*-*, c2-*-*
7394 ARM RISCix arm-*-* (as host)
7398 * GDB has been converted to ISO C.
7400 GDB's source code has been converted to ISO C. In particular, the
7401 sources are fully protoized, and rely on standard headers being
7406 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
7408 * The MI enabled by default.
7410 The new machine oriented interface (MI) introduced in GDB 5.0 has been
7411 revised and enabled by default. Packages which use GDB as a debugging
7412 engine behind a UI or another front end are encouraged to switch to
7413 using the GDB/MI interface, instead of the old annotations interface
7414 which is now deprecated.
7416 * Support for debugging Pascal programs.
7418 GDB now includes support for debugging Pascal programs. The following
7419 main features are supported:
7421 - Pascal-specific data types such as sets;
7423 - automatic recognition of Pascal sources based on file-name
7426 - Pascal-style display of data types, variables, and functions;
7428 - a Pascal expression parser.
7430 However, some important features are not yet supported.
7432 - Pascal string operations are not supported at all;
7434 - there are some problems with boolean types;
7436 - Pascal type hexadecimal constants are not supported
7437 because they conflict with the internal variables format;
7439 - support for Pascal objects and classes is not full yet;
7441 - unlike Pascal, GDB is case-sensitive for symbol names.
7443 * Changes in completion.
7445 Commands such as `shell', `run' and `set args', which pass arguments
7446 to inferior programs, now complete on file names, similar to what
7447 users expect at the shell prompt.
7449 Commands which accept locations, such as `disassemble', `print',
7450 `breakpoint', `until', etc. now complete on filenames as well as
7451 program symbols. Thus, if you type "break foob TAB", and the source
7452 files linked into the programs include `foobar.c', that file name will
7453 be one of the candidates for completion. However, file names are not
7454 considered for completion after you typed a colon that delimits a file
7455 name from a name of a function in that file, as in "break foo.c:bar".
7457 `set demangle-style' completes on available demangling styles.
7459 * New platform-independent commands:
7461 It is now possible to define a post-hook for a command as well as a
7462 hook that runs before the command. For more details, see the
7463 documentation of `hookpost' in the GDB manual.
7465 * Changes in GNU/Linux native debugging.
7467 Support for debugging multi-threaded programs has been completely
7468 revised for all platforms except m68k and sparc. You can now debug as
7469 many threads as your system allows you to have.
7471 Attach/detach is supported for multi-threaded programs.
7473 Support for SSE registers was added for x86. This doesn't work for
7474 multi-threaded programs though.
7476 * Changes in MIPS configurations.
7478 Multi-arch support is enabled for all MIPS configurations.
7480 GDB can now be built as native debugger on SGI Irix 6.x systems for
7481 debugging n32 executables. (Debugging 64-bit executables is not yet
7484 * Unified support for hardware watchpoints in all x86 configurations.
7486 Most (if not all) native x86 configurations support hardware-assisted
7487 breakpoints and watchpoints in a unified manner. This support
7488 implements debug register sharing between watchpoints, which allows to
7489 put a virtually infinite number of watchpoints on the same address,
7490 and also supports watching regions up to 16 bytes with several debug
7493 The new maintenance command `maintenance show-debug-regs' toggles
7494 debugging print-outs in functions that insert, remove, and test
7495 watchpoints and hardware breakpoints.
7497 * Changes in the DJGPP native configuration.
7499 New command ``info dos sysinfo'' displays assorted information about
7500 the CPU, OS, memory, and DPMI server.
7502 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
7503 display information about segment descriptors stored in GDT, LDT, and
7506 New commands ``info dos pde'' and ``info dos pte'' display entries
7507 from Page Directory and Page Tables (for now works with CWSDPMI only).
7508 New command ``info dos address-pte'' displays the Page Table entry for
7509 a given linear address.
7511 GDB can now pass command lines longer than 126 characters to the
7512 program being debugged (requires an update to the libdbg.a library
7513 which is part of the DJGPP development kit).
7515 DWARF2 debug info is now supported.
7517 It is now possible to `step' and `next' through calls to `longjmp'.
7519 * Changes in documentation.
7521 All GDB documentation was converted to GFDL, the GNU Free
7522 Documentation License.
7524 Tracepoints-related commands are now fully documented in the GDB
7527 TUI, the Text-mode User Interface, is now documented in the manual.
7529 Tracepoints-related commands are now fully documented in the GDB
7532 The "GDB Internals" manual now has an index. It also includes
7533 documentation of `ui_out' functions, GDB coding standards, x86
7534 hardware watchpoints, and memory region attributes.
7536 * GDB's version number moved to ``version.in''
7538 The Makefile variable VERSION has been replaced by the file
7539 ``version.in''. People creating GDB distributions should update the
7540 contents of this file.
7544 GUD support is now a standard part of the EMACS distribution.
7546 *** Changes in GDB 5.0:
7548 * Improved support for debugging FP programs on x86 targets
7550 Unified and much-improved support for debugging floating-point
7551 programs on all x86 targets. In particular, ``info float'' now
7552 displays the FP registers in the same format on all x86 targets, with
7553 greater level of detail.
7555 * Improvements and bugfixes in hardware-assisted watchpoints
7557 It is now possible to watch array elements, struct members, and
7558 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7559 on x86 targets no longer erroneously trigger when the address is
7562 * Improvements in the native DJGPP version of GDB
7564 The distribution now includes all the scripts and auxiliary files
7565 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7566 machines ``out of the box''.
7568 The DJGPP version can now debug programs that use signals. It is
7569 possible to catch signals that happened in the debuggee, deliver
7570 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7571 would kill the program being debugged.) Programs that hook hardware
7572 interrupts (keyboard, timer, etc.) can also be debugged.
7574 It is now possible to debug DJGPP programs that redirect their
7575 standard handles or switch them to raw (as opposed to cooked) mode, or
7576 even close them. The command ``run < foo > bar'' works as expected,
7577 and ``info terminal'' reports useful information about the debuggee's
7578 terminal, including raw/cooked mode, redirection, etc.
7580 The DJGPP version now uses termios functions for console I/O, which
7581 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7584 DOS-style file names with drive letters are now fully supported by
7587 It is now possible to debug DJGPP programs that switch their working
7588 directory. It is also possible to rerun the debuggee any number of
7589 times without restarting GDB; thus, you can use the same setup,
7590 breakpoints, etc. for many debugging sessions.
7592 * New native configurations
7594 ARM GNU/Linux arm*-*-linux*
7595 PowerPC GNU/Linux powerpc-*-linux*
7599 Motorola MCore mcore-*-*
7600 x86 VxWorks i[3456]86-*-vxworks*
7601 PowerPC VxWorks powerpc-*-vxworks*
7602 TI TMS320C80 tic80-*-*
7604 * OBSOLETE configurations
7606 Altos 3068 m68*-altos-*
7607 Convex c1-*-*, c2-*-*
7609 ARM RISCix arm-*-* (as host)
7612 Configurations that have been declared obsolete will be commented out,
7613 but the code will be left in place. If there is no activity to revive
7614 these configurations before the next release of GDB, the sources will
7615 be permanently REMOVED.
7617 * Gould support removed
7619 Support for the Gould PowerNode and NP1 has been removed.
7621 * New features for SVR4
7623 On SVR4 native platforms (such as Solaris), if you attach to a process
7624 without first loading a symbol file, GDB will now attempt to locate and
7625 load symbols from the running process's executable file.
7627 * Many C++ enhancements
7629 C++ support has been greatly improved. Overload resolution now works properly
7630 in almost all cases. RTTI support is on the way.
7632 * Remote targets can connect to a sub-program
7634 A popen(3) style serial-device has been added. This device starts a
7635 sub-process (such as a stand-alone simulator) and then communicates
7636 with that. The sub-program to run is specified using the syntax
7637 ``|<program> <args>'' vis:
7639 (gdb) set remotedebug 1
7640 (gdb) target extended-remote |mn10300-elf-sim program-args
7642 * MIPS 64 remote protocol
7644 A long standing bug in the mips64 remote protocol where by GDB
7645 expected certain 32 bit registers (ex SR) to be transfered as 32
7646 instead of 64 bits has been fixed.
7648 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7649 added to provide backward compatibility with older versions of GDB.
7651 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7653 The command ``set remotebinarydownload'' command has been replaced by
7654 ``set remote X-packet''. Other commands in ``set remote'' family
7655 include ``set remote P-packet''.
7657 * Breakpoint commands accept ranges.
7659 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7660 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7661 ``tracepoint passcount'' also accepts a range of tracepoints.
7663 * ``apropos'' command added.
7665 The ``apropos'' command searches through command names and
7666 documentation strings, printing out matches, making it much easier to
7667 try to find a command that does what you are looking for.
7671 A new machine oriented interface (MI) has been added to GDB. This
7672 interface is designed for debug environments running GDB as a separate
7673 process. This is part of the long term libGDB project. See the
7674 "GDB/MI" chapter of the GDB manual for further information. It can be
7675 enabled by configuring with:
7677 .../configure --enable-gdbmi
7679 *** Changes in GDB-4.18:
7681 * New native configurations
7683 HP-UX 10.20 hppa*-*-hpux10.20
7684 HP-UX 11.x hppa*-*-hpux11.0*
7685 M68K GNU/Linux m68*-*-linux*
7689 Fujitsu FR30 fr30-*-elf*
7690 Intel StrongARM strongarm-*-*
7691 Mitsubishi D30V d30v-*-*
7693 * OBSOLETE configurations
7695 Gould PowerNode, NP1 np1-*-*, pn-*-*
7697 Configurations that have been declared obsolete will be commented out,
7698 but the code will be left in place. If there is no activity to revive
7699 these configurations before the next release of GDB, the sources will
7700 be permanently REMOVED.
7704 As a compatibility experiment, GDB's source files buildsym.h and
7705 buildsym.c have been converted to pure standard C, no longer
7706 containing any K&R compatibility code. We believe that all systems in
7707 use today either come with a standard C compiler, or have a GCC port
7708 available. If this is not true, please report the affected
7709 configuration to bug-gdb@gnu.org immediately. See the README file for
7710 information about getting a standard C compiler if you don't have one
7715 GDB now uses readline 2.2.
7717 * set extension-language
7719 You can now control the mapping between filename extensions and source
7720 languages by using the `set extension-language' command. For instance,
7721 you can ask GDB to treat .c files as C++ by saying
7722 set extension-language .c c++
7723 The command `info extensions' lists all of the recognized extensions
7724 and their associated languages.
7726 * Setting processor type for PowerPC and RS/6000
7728 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7729 you can use the `set processor' command to specify what variant of the
7730 PowerPC family you are debugging. The command
7734 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7735 following PowerPC and RS6000 variants:
7737 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7738 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7740 403GC IBM PowerPC 403GC
7741 505 Motorola PowerPC 505
7742 860 Motorola PowerPC 860 or 850
7743 601 Motorola PowerPC 601
7744 602 Motorola PowerPC 602
7745 603 Motorola/IBM PowerPC 603 or 603e
7746 604 Motorola PowerPC 604 or 604e
7747 750 Motorola/IBM PowerPC 750 or 750
7749 At the moment, this command just tells GDB what to name the
7750 special-purpose processor registers. Since almost all the affected
7751 registers are inaccessible to user-level programs, this command is
7752 only useful for remote debugging in its present form.
7756 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7757 more extensive support for HP-UX. Added features include shared
7758 library support, kernel threads and hardware watchpoints for 11.00,
7759 support for HP's ANSI C and C++ compilers, and a compatibility mode
7760 for xdb and dbx commands.
7764 HP's donation includes the new concept of catchpoints, which is a
7765 generalization of the old catch command. On HP-UX, it is now possible
7766 to catch exec, fork, and vfork, as well as library loading.
7768 This means that the existing catch command has changed; its first
7769 argument now specifies the type of catch to be set up. See the
7770 output of "help catch" for a list of catchpoint types.
7772 * Debugging across forks
7774 On HP-UX, you can choose which process to debug when a fork() happens
7779 HP has donated a curses-based terminal user interface (TUI). To get
7780 it, build with --enable-tui. Although this can be enabled for any
7781 configuration, at present it only works for native HP debugging.
7783 * GDB remote protocol additions
7785 A new protocol packet 'X' that writes binary data is now available.
7786 Default behavior is to try 'X', then drop back to 'M' if the stub
7787 fails to respond. The settable variable `remotebinarydownload'
7788 allows explicit control over the use of 'X'.
7790 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7791 full 64-bit address. The command
7793 set remoteaddresssize 32
7795 can be used to revert to the old behaviour. For existing remote stubs
7796 the change should not be noticed, as the additional address information
7799 In order to assist in debugging stubs, you may use the maintenance
7800 command `packet' to send any text string to the stub. For instance,
7802 maint packet heythere
7804 sends the packet "$heythere#<checksum>". Note that it is very easy to
7805 disrupt a debugging session by sending the wrong packet at the wrong
7808 The compare-sections command allows you to compare section data on the
7809 target to what is in the executable file without uploading or
7810 downloading, by comparing CRC checksums.
7812 * Tracing can collect general expressions
7814 You may now collect general expressions at tracepoints. This requires
7815 further additions to the target-side stub; see tracepoint.c and
7816 doc/agentexpr.texi for further details.
7818 * mask-address variable for Mips
7820 For Mips targets, you may control the zeroing of the upper 32 bits of
7821 a 64-bit address by entering `set mask-address on'. This is mainly
7822 of interest to users of embedded R4xxx and R5xxx processors.
7824 * Higher serial baud rates
7826 GDB's serial code now allows you to specify baud rates 57600, 115200,
7827 230400, and 460800 baud. (Note that your host system may not be able
7828 to achieve all of these rates.)
7832 The i960 configuration now includes an initial implementation of a
7833 builtin simulator, contributed by Jim Wilson.
7836 *** Changes in GDB-4.17:
7838 * New native configurations
7840 Alpha GNU/Linux alpha*-*-linux*
7841 Unixware 2.x i[3456]86-unixware2*
7842 Irix 6.x mips*-sgi-irix6*
7843 PowerPC GNU/Linux powerpc-*-linux*
7844 PowerPC Solaris powerpcle-*-solaris*
7845 Sparc GNU/Linux sparc-*-linux*
7846 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7850 Argonaut Risc Chip (ARC) arc-*-*
7851 Hitachi H8/300S h8300*-*-*
7852 Matsushita MN10200 w/simulator mn10200-*-*
7853 Matsushita MN10300 w/simulator mn10300-*-*
7854 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7855 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7856 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7857 Mitsubishi D10V w/simulator d10v-*-*
7858 Mitsubishi M32R/D w/simulator m32r-*-elf*
7859 Tsqware Sparclet sparclet-*-*
7860 NEC V850 w/simulator v850-*-*
7862 * New debugging protocols
7864 ARM with RDI protocol arm*-*-*
7865 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7866 DDB and LSI variants of PMON protocol mips*-*-*
7867 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7868 PowerPC with SDS protocol powerpc{,le}-*-eabi
7869 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7873 All configurations can now understand and use the DWARF 2 debugging
7874 format. The choice is automatic, if the symbol file contains DWARF 2
7879 GDB now includes basic Java language support. This support is
7880 only useful with Java compilers that produce native machine code.
7882 * solib-absolute-prefix and solib-search-path
7884 For SunOS and SVR4 shared libraries, you may now set the prefix for
7885 loading absolute shared library symbol files, and the search path for
7886 locating non-absolute shared library symbol files.
7888 * Live range splitting
7890 GDB can now effectively debug code for which GCC has performed live
7891 range splitting as part of its optimization. See gdb/doc/LRS for
7892 more details on the expected format of the stabs information.
7896 GDB's support for the GNU Hurd, including thread debugging, has been
7897 updated to work with current versions of the Hurd.
7901 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7902 instruction set. ARM GDB automatically detects when Thumb
7903 instructions are in use, and adjusts disassembly and backtracing
7908 GDB's MIPS target configurations now handle the MIP16 16-bit
7913 GDB now includes support for overlays; if an executable has been
7914 linked such that multiple sections are based at the same address, GDB
7915 will decide which section to use for symbolic info. You can choose to
7916 control the decision manually, using overlay commands, or implement
7917 additional target-side support and use "overlay load-target" to bring
7918 in the overlay mapping. Do "help overlay" for more detail.
7922 The command "info symbol <address>" displays information about
7923 the symbol at the specified address.
7927 The standard remote protocol now includes an extension that allows
7928 asynchronous collection and display of trace data. This requires
7929 extensive support in the target-side debugging stub. Tracing mode
7930 includes a new interaction mode in GDB and new commands: see the
7931 file tracepoint.c for more details.
7935 Configurations for embedded MIPS now include a simulator contributed
7936 by Cygnus Solutions. The simulator supports the instruction sets
7937 of most MIPS variants.
7941 Sparc configurations may now include the ERC32 simulator contributed
7942 by the European Space Agency. The simulator is not built into
7943 Sparc targets by default; configure with --enable-sim to include it.
7947 For target configurations that may include multiple variants of a
7948 basic architecture (such as MIPS and SH), you may now set the
7949 architecture explicitly. "set arch" sets, "info arch" lists
7950 the possible architectures.
7952 *** Changes in GDB-4.16:
7954 * New native configurations
7956 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7957 M68K NetBSD m68k-*-netbsd*
7958 PowerPC AIX 4.x powerpc-*-aix*
7959 PowerPC MacOS powerpc-*-macos*
7960 PowerPC Windows NT powerpcle-*-cygwin32
7961 RS/6000 AIX 4.x rs6000-*-aix4*
7965 ARM with RDP protocol arm-*-*
7966 I960 with MON960 i960-*-coff
7967 MIPS VxWorks mips*-*-vxworks*
7968 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7969 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7971 Matra Sparclet sparclet-*-*
7975 The powerpc-eabi configuration now includes the PSIM simulator,
7976 contributed by Andrew Cagney, with assistance from Mike Meissner.
7977 PSIM is a very elaborate model of the PowerPC, including not only
7978 basic instruction set execution, but also details of execution unit
7979 performance and I/O hardware. See sim/ppc/README for more details.
7983 GDB now works with Solaris 2.5.
7985 * Windows 95/NT native
7987 GDB will now work as a native debugger on Windows 95 and Windows NT.
7988 To build it from source, you must use the "gnu-win32" environment,
7989 which uses a DLL to emulate enough of Unix to run the GNU tools.
7990 Further information, binaries, and sources are available at
7991 ftp.cygnus.com, under pub/gnu-win32.
7993 * dont-repeat command
7995 If a user-defined command includes the command `dont-repeat', then the
7996 command will not be repeated if the user just types return. This is
7997 useful if the command is time-consuming to run, so that accidental
7998 extra keystrokes don't run the same command many times.
8000 * Send break instead of ^C
8002 The standard remote protocol now includes an option to send a break
8003 rather than a ^C to the target in order to interrupt it. By default,
8004 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
8006 * Remote protocol timeout
8008 The standard remote protocol includes a new variable `remotetimeout'
8009 that allows you to set the number of seconds before GDB gives up trying
8010 to read from the target. The default value is 2.
8012 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
8014 By default GDB will automatically keep track of objects as they are
8015 loaded and unloaded by the dynamic linker. By using the command `set
8016 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
8017 when shared library events occur, thus allowing you to set breakpoints
8018 in shared libraries which are explicitly loaded by the inferior.
8020 Note this feature does not work on hpux8. On hpux9 you must link
8021 /usr/lib/end.o into your program. This feature should work
8022 automatically on hpux10.
8024 * Irix 5.x hardware watchpoint support
8026 Irix 5 configurations now support the use of hardware watchpoints.
8028 * Mips protocol "SYN garbage limit"
8030 When debugging a Mips target using the `target mips' protocol, you
8031 may set the number of characters that GDB will ignore by setting
8032 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
8033 every character. The default value is 1050.
8035 * Recording and replaying remote debug sessions
8037 If you set `remotelogfile' to the name of a file, gdb will write to it
8038 a recording of a remote debug session. This recording may then be
8039 replayed back to gdb using "gdbreplay". See gdbserver/README for
8040 details. This is useful when you have a problem with GDB while doing
8041 remote debugging; you can make a recording of the session and send it
8042 to someone else, who can then recreate the problem.
8044 * Speedups for remote debugging
8046 GDB includes speedups for downloading and stepping MIPS systems using
8047 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
8048 and more efficient S-record downloading.
8050 * Memory use reductions and statistics collection
8052 GDB now uses less memory and reports statistics about memory usage.
8053 Try the `maint print statistics' command, for example.
8055 *** Changes in GDB-4.15:
8057 * Psymtabs for XCOFF
8059 The symbol reader for AIX GDB now uses partial symbol tables. This
8060 can greatly improve startup time, especially for large executables.
8062 * Remote targets use caching
8064 Remote targets now use a data cache to speed up communication with the
8065 remote side. The data cache could lead to incorrect results because
8066 it doesn't know about volatile variables, thus making it impossible to
8067 debug targets which use memory mapped I/O devices. `set remotecache
8068 off' turns the data cache off.
8070 * Remote targets may have threads
8072 The standard remote protocol now includes support for multiple threads
8073 in the target system, using new protocol commands 'H' and 'T'. See
8074 gdb/remote.c for details.
8078 If GDB is configured with `--enable-netrom', then it will include
8079 support for the NetROM ROM emulator from XLNT Designs. The NetROM
8080 acts as though it is a bank of ROM on the target board, but you can
8081 write into it over the network. GDB's support consists only of
8082 support for fast loading into the emulated ROM; to debug, you must use
8083 another protocol, such as standard remote protocol. The usual
8084 sequence is something like
8086 target nrom <netrom-hostname>
8088 target remote <netrom-hostname>:1235
8092 GDB now includes support for the Apple Macintosh, as a host only. It
8093 may be run as either an MPW tool or as a standalone application, and
8094 it can debug through the serial port. All the usual GDB commands are
8095 available, but to the target command, you must supply "serial" as the
8096 device type instead of "/dev/ttyXX". See mpw-README in the main
8097 directory for more information on how to build. The MPW configuration
8098 scripts */mpw-config.in support only a few targets, and only the
8099 mips-idt-ecoff target has been tested.
8103 GDB configuration now uses autoconf. This is not user-visible,
8104 but does simplify configuration and building.
8108 GDB now supports hpux10.
8110 *** Changes in GDB-4.14:
8112 * New native configurations
8114 x86 FreeBSD i[345]86-*-freebsd
8115 x86 NetBSD i[345]86-*-netbsd
8116 NS32k NetBSD ns32k-*-netbsd
8117 Sparc NetBSD sparc-*-netbsd
8121 A29K VxWorks a29k-*-vxworks
8122 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
8123 CPU32 EST-300 emulator m68*-*-est*
8124 PowerPC ELF powerpc-*-elf
8127 * Alpha OSF/1 support for procfs
8129 GDB now supports procfs under OSF/1-2.x and higher, which makes it
8130 possible to attach to running processes. As the mounting of the /proc
8131 filesystem is optional on the Alpha, GDB automatically determines
8132 the availability of /proc during startup. This can lead to problems
8133 if /proc is unmounted after GDB has been started.
8135 * Arguments to user-defined commands
8137 User commands may accept up to 10 arguments separated by whitespace.
8138 Arguments are accessed within the user command via $arg0..$arg9. A
8141 print $arg0 + $arg1 + $arg2
8143 To execute the command use:
8146 Defines the command "adder" which prints the sum of its three arguments.
8147 Note the arguments are text substitutions, so they may reference variables,
8148 use complex expressions, or even perform inferior function calls.
8150 * New `if' and `while' commands
8152 This makes it possible to write more sophisticated user-defined
8153 commands. Both commands take a single argument, which is the
8154 expression to evaluate, and must be followed by the commands to
8155 execute, one per line, if the expression is nonzero, the list being
8156 terminated by the word `end'. The `if' command list may include an
8157 `else' word, which causes the following commands to be executed only
8158 if the expression is zero.
8160 * Fortran source language mode
8162 GDB now includes partial support for Fortran 77. It will recognize
8163 Fortran programs and can evaluate a subset of Fortran expressions, but
8164 variables and functions may not be handled correctly. GDB will work
8165 with G77, but does not yet know much about symbols emitted by other
8168 * Better HPUX support
8170 Most debugging facilities now work on dynamic executables for HPPAs
8171 running hpux9 or later. You can attach to running dynamically linked
8172 processes, but by default the dynamic libraries will be read-only, so
8173 for instance you won't be able to put breakpoints in them. To change
8174 that behavior do the following before running the program:
8180 This will cause the libraries to be mapped private and read-write.
8181 To revert to the normal behavior, do this:
8187 You cannot set breakpoints or examine data in the library until after
8188 the library is loaded if the function/data symbols do not have
8191 GDB can now also read debug symbols produced by the HP C compiler on
8192 HPPAs (sorry, no C++, Fortran or 68k support).
8194 * Target byte order now dynamically selectable
8196 You can choose which byte order to use with a target system, via the
8197 commands "set endian big" and "set endian little", and you can see the
8198 current setting by using "show endian". You can also give the command
8199 "set endian auto", in which case GDB will use the byte order
8200 associated with the executable. Currently, only embedded MIPS
8201 configurations support dynamic selection of target byte order.
8203 * New DOS host serial code
8205 This version uses DPMI interrupts to handle buffered I/O, so you
8206 no longer need to run asynctsr when debugging boards connected to
8209 *** Changes in GDB-4.13:
8211 * New "complete" command
8213 This lists all the possible completions for the rest of the line, if it
8214 were to be given as a command itself. This is intended for use by emacs.
8216 * Trailing space optional in prompt
8218 "set prompt" no longer adds a space for you after the prompt you set. This
8219 allows you to set a prompt which ends in a space or one that does not.
8221 * Breakpoint hit counts
8223 "info break" now displays a count of the number of times the breakpoint
8224 has been hit. This is especially useful in conjunction with "ignore"; you
8225 can ignore a large number of breakpoint hits, look at the breakpoint info
8226 to see how many times the breakpoint was hit, then run again, ignoring one
8227 less than that number, and this will get you quickly to the last hit of
8230 * Ability to stop printing at NULL character
8232 "set print null-stop" will cause GDB to stop printing the characters of
8233 an array when the first NULL is encountered. This is useful when large
8234 arrays actually contain only short strings.
8236 * Shared library breakpoints
8238 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
8239 breakpoints in shared libraries before the executable is run.
8241 * Hardware watchpoints
8243 There is a new hardware breakpoint for the watch command for sparclite
8244 targets. See gdb/sparclite/hw_breakpoint.note.
8246 Hardware watchpoints are also now supported under GNU/Linux.
8250 Annotations have been added. These are for use with graphical interfaces,
8251 and are still experimental. Currently only gdba.el uses these.
8253 * Improved Irix 5 support
8255 GDB now works properly with Irix 5.2.
8257 * Improved HPPA support
8259 GDB now works properly with the latest GCC and GAS.
8261 * New native configurations
8263 Sequent PTX4 i[34]86-sequent-ptx4
8264 HPPA running OSF/1 hppa*-*-osf*
8265 Atari TT running SVR4 m68*-*-sysv4*
8266 RS/6000 LynxOS rs6000-*-lynxos*
8270 OS/9000 i[34]86-*-os9k
8271 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
8274 * Hitachi SH7000 and E7000-PC ICE support
8276 There is now support for communicating with the Hitachi E7000-PC ICE.
8277 This is available automatically when GDB is configured for the SH.
8281 As usual, a variety of small fixes and improvements, both generic
8282 and configuration-specific. See the ChangeLog for more detail.
8284 *** Changes in GDB-4.12:
8286 * Irix 5 is now supported
8290 GDB-4.12 on the HPPA has a number of changes which make it unable
8291 to debug the output from the currently released versions of GCC and
8292 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8293 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8294 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8297 *** Changes in GDB-4.11:
8299 * User visible changes:
8303 The "set remotedebug" option is now consistent between the mips remote
8304 target, remote targets using the gdb-specific protocol, UDI (AMD's
8305 debug protocol for the 29k) and the 88k bug monitor. It is now an
8306 integer specifying a debug level (normally 0 or 1, but 2 means more
8307 debugging info for the mips target).
8309 * DEC Alpha native support
8311 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8312 debug info, but GDB works fairly well with the DEC compiler and should
8313 work with a future GCC release. See the README file for a few
8314 Alpha-specific notes.
8316 * Preliminary thread implementation
8318 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8320 * LynxOS native and target support for 386
8322 This release has been hosted on LynxOS 2.2, and also can be configured
8323 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8326 * Improvements in C++ mangling/demangling.
8328 This release has much better g++ debugging, specifically in name
8329 mangling/demangling, virtual function calls, print virtual table,
8330 call methods, ...etc.
8332 *** Changes in GDB-4.10:
8334 * User visible changes:
8336 Remote debugging using the GDB-specific (`target remote') protocol now
8337 supports the `load' command. This is only useful if you have some
8338 other way of getting the stub to the target system, and you can put it
8339 somewhere in memory where it won't get clobbered by the download.
8341 Filename completion now works.
8343 When run under emacs mode, the "info line" command now causes the
8344 arrow to point to the line specified. Also, "info line" prints
8345 addresses in symbolic form (as well as hex).
8347 All vxworks based targets now support a user settable option, called
8348 vxworks-timeout. This option represents the number of seconds gdb
8349 should wait for responses to rpc's. You might want to use this if
8350 your vxworks target is, perhaps, a slow software simulator or happens
8351 to be on the far side of a thin network line.
8355 This release contains support for using a DEC alpha as a GDB host for
8356 cross debugging. Native alpha debugging is not supported yet.
8359 *** Changes in GDB-4.9:
8363 This is the first GDB release which is accompanied by a matching testsuite.
8364 The testsuite requires installation of dejagnu, which should be available
8365 via ftp from most sites that carry GNU software.
8369 'Cfront' style demangling has had its name changed to 'ARM' style, to
8370 emphasize that it was written from the specifications in the C++ Annotated
8371 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8372 disclaimers, it still generated too much confusion with users attempting to
8373 use gdb with AT&T cfront.
8377 GDB now uses a standard remote interface to a simulator library.
8378 So far, the library contains simulators for the Zilog Z8001/2, the
8379 Hitachi H8/300, H8/500 and Super-H.
8381 * New targets supported
8383 H8/300 simulator h8300-hitachi-hms or h8300hms
8384 H8/500 simulator h8500-hitachi-hms or h8500hms
8385 SH simulator sh-hitachi-hms or sh
8386 Z8000 simulator z8k-zilog-none or z8ksim
8387 IDT MIPS board over serial line mips-idt-ecoff
8389 Cross-debugging to GO32 targets is supported. It requires a custom
8390 version of the i386-stub.c module which is integrated with the
8391 GO32 memory extender.
8393 * New remote protocols
8395 MIPS remote debugging protocol.
8397 * New source languages supported
8399 This version includes preliminary support for Chill, a Pascal like language
8400 used by telecommunications companies. Chill support is also being integrated
8401 into the GNU compiler, but we don't know when it will be publically available.
8404 *** Changes in GDB-4.8:
8406 * HP Precision Architecture supported
8408 GDB now supports HP PA-RISC machines running HPUX. A preliminary
8409 version of this support was available as a set of patches from the
8410 University of Utah. GDB does not support debugging of programs
8411 compiled with the HP compiler, because HP will not document their file
8412 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
8413 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
8415 Many problems in the preliminary version have been fixed.
8417 * Faster and better demangling
8419 We have improved template demangling and fixed numerous bugs in the GNU style
8420 demangler. It can now handle type modifiers such as `static' or `const'. Wide
8421 character types (wchar_t) are now supported. Demangling of each symbol is now
8422 only done once, and is cached when the symbol table for a file is read in.
8423 This results in a small increase in memory usage for C programs, a moderate
8424 increase in memory usage for C++ programs, and a fantastic speedup in
8427 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
8428 from the specifications in the Annotated Reference Manual, which AT&T's
8429 compiler does not actually implement.
8431 * G++ multiple inheritance compiler problem
8433 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
8434 inheritance lattices was reworked to properly discover ambiguities. We
8435 recently found an example which causes this new algorithm to fail in a
8436 very subtle way, producing bad debug information for those classes.
8437 The file 'gcc.patch' (in this directory) can be applied to gcc to
8438 circumvent the problem. A future GCC release will contain a complete
8441 The previous G++ debug info problem (mentioned below for the gdb-4.7
8442 release) is fixed in gcc version 2.3.2.
8444 * Improved configure script
8446 The `configure' script will now attempt to guess your system type if
8447 you don't supply a host system type. The old scheme of supplying a
8448 host system triplet is preferable over using this. All the magic is
8449 done in the new `config.guess' script. Examine it for details.
8451 We have also brought our configure script much more in line with the FSF's
8452 version. It now supports the --with-xxx options. In particular,
8453 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
8454 The resulting GDB will not be able to read arbitrary object file formats --
8455 only the format ``expected'' to be used on the configured target system.
8456 We hope to make this the default in a future release.
8458 * Documentation improvements
8460 There's new internal documentation on how to modify GDB, and how to
8461 produce clean changes to the code. We implore people to read it
8462 before submitting changes.
8464 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
8465 M4 macros. The new texinfo.tex is provided in this release. Pre-built
8466 `info' files are also provided. To build `info' files from scratch,
8467 you will need the latest `makeinfo' release, which will be available in
8468 a future texinfo-X.Y release.
8470 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
8471 We're not sure exactly which versions have this problem, but it has
8472 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
8473 or better. If that isn't possible, there is a patch in
8474 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
8475 around this problem.
8479 GDB now supports array constants that can be used in expressions typed in by
8480 the user. The syntax is `{element, element, ...}'. Ie: you can now type
8481 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
8484 The new directory `gdb/sparclite' contains a program that demonstrates
8485 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
8487 * New native hosts supported
8489 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
8490 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
8492 * New targets supported
8494 AMD 29k family via UDI a29k-amd-udi or udi29k
8496 * New file formats supported
8498 BFD now supports reading HP/PA-RISC executables (SOM file format?),
8499 HPUX core files, and SCO 3.2v2 core files.
8503 Attaching to processes now works again; thanks for the many bug reports.
8505 We have also stomped on a bunch of core dumps caused by
8506 printf_filtered("%s") problems.
8508 We eliminated a copyright problem on the rpc and ptrace header files
8509 for VxWorks, which was discovered at the last minute during the 4.7
8510 release. You should now be able to build a VxWorks GDB.
8512 You can now interrupt gdb while an attached process is running. This
8513 will cause the attached process to stop, and give control back to GDB.
8515 We fixed problems caused by using too many file descriptors
8516 for reading symbols from object files and libraries. This was
8517 especially a problem for programs that used many (~100) shared
8520 The `step' command now only enters a subroutine if there is line number
8521 information for the subroutine. Otherwise it acts like the `next'
8522 command. Previously, `step' would enter subroutines if there was
8523 any debugging information about the routine. This avoids problems
8524 when using `cc -g1' on MIPS machines.
8526 * Internal improvements
8528 GDB's internal interfaces have been improved to make it easier to support
8529 debugging of multiple languages in the future.
8531 GDB now uses a common structure for symbol information internally.
8532 Minimal symbols (derived from linkage symbols in object files), partial
8533 symbols (from a quick scan of debug information), and full symbols
8534 contain a common subset of information, making it easier to write
8535 shared code that handles any of them.
8537 * New command line options
8539 We now accept --silent as an alias for --quiet.
8543 The memory-mapped-malloc library is now licensed under the GNU Library
8544 General Public License.
8546 *** Changes in GDB-4.7:
8548 * Host/native/target split
8550 GDB has had some major internal surgery to untangle the support for
8551 hosts and remote targets. Now, when you configure GDB for a remote
8552 target, it will no longer load in all of the support for debugging
8553 local programs on the host. When fully completed and tested, this will
8554 ensure that arbitrary host/target combinations are possible.
8556 The primary conceptual shift is to separate the non-portable code in
8557 GDB into three categories. Host specific code is required any time GDB
8558 is compiled on that host, regardless of the target. Target specific
8559 code relates to the peculiarities of the target, but can be compiled on
8560 any host. Native specific code is everything else: it can only be
8561 built when the host and target are the same system. Child process
8562 handling and core file support are two common `native' examples.
8564 GDB's use of /proc for controlling Unix child processes is now cleaner.
8565 It has been split out into a single module under the `target_ops' vector,
8566 plus two native-dependent functions for each system that uses /proc.
8568 * New hosts supported
8570 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8571 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8572 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8574 * New targets supported
8576 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8577 68030 and CPU32 m68030-*-*, m68332-*-*
8579 * New native hosts supported
8581 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8582 (386bsd is not well tested yet)
8583 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8585 * New file formats supported
8587 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8588 supports reading of `a.out.adobe' object files, which are an a.out
8589 format extended with minimal information about multiple sections.
8593 `show copying' is the same as the old `info copying'.
8594 `show warranty' is the same as `info warrantee'.
8595 These were renamed for consistency. The old commands continue to work.
8597 `info handle' is a new alias for `info signals'.
8599 You can now define pre-command hooks, which attach arbitrary command
8600 scripts to any command. The commands in the hook will be executed
8601 prior to the user's command. You can also create a hook which will be
8602 executed whenever the program stops. See gdb.texinfo.
8606 We now deal with Cfront style name mangling, and can even extract type
8607 info from mangled symbols. GDB can automatically figure out which
8608 symbol mangling style your C++ compiler uses.
8610 Calling of methods and virtual functions has been improved as well.
8614 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8615 fixed. This was due to mishandling of the extra N_SO stabs output
8618 We also finally got Ultrix 4.2 running in house, and fixed core file
8619 support, with help from a dozen people on the net.
8621 John M. Farrell discovered that the reason that single-stepping was so
8622 slow on all of the Mips based platforms (primarily SGI and DEC) was
8623 that we were trying to demangle and lookup a symbol used for internal
8624 purposes on every instruction that was being stepped through. Changing
8625 the name of that symbol so that it couldn't be mistaken for a C++
8626 mangled symbol sped things up a great deal.
8628 Rich Pixley sped up symbol lookups in general by getting much smarter
8629 about when C++ symbol mangling is necessary. This should make symbol
8630 completion (TAB on the command line) much faster. It's not as fast as
8631 we'd like, but it's significantly faster than gdb-4.6.
8635 A new user controllable variable 'call_scratch_address' can
8636 specify the location of a scratch area to be used when GDB
8637 calls a function in the target. This is necessary because the
8638 usual method of putting the scratch area on the stack does not work
8639 in systems that have separate instruction and data spaces.
8641 We integrated changes to support the 29k UDI (Universal Debugger
8642 Interface), but discovered at the last minute that we didn't have all
8643 of the appropriate copyright paperwork. We are working with AMD to
8644 resolve this, and hope to have it available soon.
8648 We have sped up the remote serial line protocol, especially for targets
8649 with lots of registers. It now supports a new `expedited status' ('T')
8650 message which can be used in place of the existing 'S' status message.
8651 This allows the remote stub to send only the registers that GDB
8652 needs to make a quick decision about single-stepping or conditional
8653 breakpoints, eliminating the need to fetch the entire register set for
8654 each instruction being stepped through.
8656 The GDB remote serial protocol now implements a write-through cache for
8657 registers, only re-reading the registers if the target has run.
8659 There is also a new remote serial stub for SPARC processors. You can
8660 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8661 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8662 processor with a serial port.
8666 Configure.in files have become much easier to read and modify. A new
8667 `table driven' format makes it more obvious what configurations are
8668 supported, and what files each one uses.
8672 There is a new opcodes library which will eventually contain all of the
8673 disassembly routines and opcode tables. At present, it only contains
8674 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8675 disassembler (binutils/objdump) to share these routines.
8677 The libiberty library is now copylefted under the GNU Library General
8678 Public License. This allows more liberal use, and was done so libg++
8679 can use it. This makes no difference to GDB, since the Library License
8680 grants all the rights from the General Public License.
8684 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8685 reference to the stabs symbol info used by the debugger. It is (as far
8686 as we know) the only published document on this fascinating topic. We
8687 encourage you to read it, compare it to the stabs information on your
8688 system, and send improvements on the document in general (to
8689 bug-gdb@prep.ai.mit.edu).
8691 And, of course, many bugs have been fixed.
8694 *** Changes in GDB-4.6:
8696 * Better support for C++ function names
8698 GDB now accepts as input the "demangled form" of C++ overloaded function
8699 names and member function names, and can do command completion on such names
8700 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8701 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8702 Make use of command completion, it is your friend.
8704 GDB also now accepts a variety of C++ mangled symbol formats. They are
8705 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8706 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8707 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8708 for the list of formats.
8710 * G++ symbol mangling problem
8712 Recent versions of gcc have a bug in how they emit debugging information for
8713 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8714 directory) can be applied to gcc to fix the problem. Alternatively, if you
8715 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8716 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8717 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8720 * New 'maintenance' command
8722 All of the commands related to hacking GDB internals have been moved out of
8723 the main command set, and now live behind the 'maintenance' command. This
8724 can also be abbreviated as 'mt'. The following changes were made:
8726 dump-me -> maintenance dump-me
8727 info all-breakpoints -> maintenance info breakpoints
8728 printmsyms -> maintenance print msyms
8729 printobjfiles -> maintenance print objfiles
8730 printpsyms -> maintenance print psymbols
8731 printsyms -> maintenance print symbols
8733 The following commands are new:
8735 maintenance demangle Call internal GDB demangler routine to
8736 demangle a C++ link name and prints the result.
8737 maintenance print type Print a type chain for a given symbol
8739 * Change to .gdbinit file processing
8741 We now read the $HOME/.gdbinit file before processing the argv arguments
8742 (e.g. reading symbol files or core files). This allows global parameters to
8743 be set, which will apply during the symbol reading. The ./.gdbinit is still
8744 read after argv processing.
8746 * New hosts supported
8748 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8750 GNU/Linux support i386-unknown-linux or linux
8752 We are also including code to support the HP/PA running BSD and HPUX. This
8753 is almost guaranteed not to work, as we didn't have time to test or build it
8754 for this release. We are including it so that the more adventurous (or
8755 masochistic) of you can play with it. We also had major problems with the
8756 fact that the compiler that we got from HP doesn't support the -g option.
8759 * New targets supported
8761 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8763 * More smarts about finding #include files
8765 GDB now remembers the compilation directory for all include files, and for
8766 all files from which C is generated (like yacc and lex sources). This
8767 greatly improves GDB's ability to find yacc/lex sources, and include files,
8768 especially if you are debugging your program from a directory different from
8769 the one that contains your sources.
8771 We also fixed a bug which caused difficulty with listing and setting
8772 breakpoints in include files which contain C code. (In the past, you had to
8773 try twice in order to list an include file that you hadn't looked at before.)
8775 * Interesting infernals change
8777 GDB now deals with arbitrary numbers of sections, where the symbols for each
8778 section must be relocated relative to that section's landing place in the
8779 target's address space. This work was needed to support ELF with embedded
8780 stabs used by Solaris-2.0.
8782 * Bug fixes (of course!)
8784 There have been loads of fixes for the following things:
8785 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8786 i960, stabs, DOS(GO32), procfs, etc...
8788 See the ChangeLog for details.
8790 *** Changes in GDB-4.5:
8792 * New machines supported (host and target)
8794 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8796 SGI Irix-4.x mips-sgi-irix4 or iris4
8798 * New malloc package
8800 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8801 Mmalloc is capable of handling multiple heaps of memory. It is also
8802 capable of saving a heap to a file, and then mapping it back in later.
8803 This can be used to greatly speedup the startup of GDB by using a
8804 pre-parsed symbol table which lives in a mmalloc managed heap. For
8805 more details, please read mmalloc/mmalloc.texi.
8809 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8810 'help info proc' for details.
8812 * MIPS ecoff symbol table format
8814 The code that reads MIPS symbol table format is now supported on all hosts.
8815 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8818 * File name changes for MS-DOS
8820 Many files in the config directories have been renamed to make it easier to
8821 support GDB on MS-DOSe systems (which have very restrictive file name
8822 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8823 environment) is close to working but has some remaining problems. Note
8824 that debugging of DOS programs is not supported, due to limitations
8825 in the ``operating system'', but it can be used to host cross-debugging.
8827 * Cross byte order fixes
8829 Many fixes have been made to support cross debugging of Sparc and MIPS
8830 targets from hosts whose byte order differs.
8832 * New -mapped and -readnow options
8834 If memory-mapped files are available on your system through the 'mmap'
8835 system call, you can use the -mapped option on the `file' or
8836 `symbol-file' commands to cause GDB to write the symbols from your
8837 program into a reusable file. If the program you are debugging is
8838 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8839 Future GDB debugging sessions will notice the presence of this file,
8840 and will quickly map in symbol information from it, rather than reading
8841 the symbol table from the executable program. Using the '-mapped'
8842 option in a GDB `file' or `symbol-file' command has the same effect as
8843 starting GDB with the '-mapped' command-line option.
8845 You can cause GDB to read the entire symbol table immediately by using
8846 the '-readnow' option with any of the commands that load symbol table
8847 information (or on the GDB command line). This makes the command
8848 slower, but makes future operations faster.
8850 The -mapped and -readnow options are typically combined in order to
8851 build a `fred.syms' file that contains complete symbol information.
8852 A simple GDB invocation to do nothing but build a `.syms' file for future
8855 gdb -batch -nx -mapped -readnow programname
8857 The `.syms' file is specific to the host machine on which GDB is run.
8858 It holds an exact image of GDB's internal symbol table. It cannot be
8859 shared across multiple host platforms.
8861 * longjmp() handling
8863 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8864 siglongjmp() without losing control. This feature has not yet been ported to
8865 all systems. It currently works on many 386 platforms, all MIPS-based
8866 platforms (SGI, DECstation, etc), and Sun3/4.
8870 Preliminary work has been put in to support the new Solaris OS from Sun. At
8871 this time, it can control and debug processes, but it is not capable of
8876 As always, many many bug fixes. The major areas were with g++, and mipsread.
8877 People using the MIPS-based platforms should experience fewer mysterious
8878 crashes and trashed symbol tables.
8880 *** Changes in GDB-4.4:
8882 * New machines supported (host and target)
8884 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8886 BSD Reno on Vax vax-dec-bsd
8887 Ultrix on Vax vax-dec-ultrix
8889 * New machines supported (target)
8891 AMD 29000 embedded, using EBMON a29k-none-none
8895 GDB continues to improve its handling of C++. `References' work better.
8896 The demangler has also been improved, and now deals with symbols mangled as
8897 per the Annotated C++ Reference Guide.
8899 GDB also now handles `stabs' symbol information embedded in MIPS
8900 `ecoff' symbol tables. Since the ecoff format was not easily
8901 extensible to handle new languages such as C++, this appeared to be a
8902 good way to put C++ debugging info into MIPS binaries. This option
8903 will be supported in the GNU C compiler, version 2, when it is
8906 * New features for SVR4
8908 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8909 shared libraries. Debugging dynamically linked programs should present
8910 only minor differences from debugging statically linked programs.
8912 The `info proc' command will print out information about any process
8913 on an SVR4 system (including the one you are debugging). At the moment,
8914 it prints the address mappings of the process.
8916 If you bring up GDB on another SVR4 system, please send mail to
8917 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8919 * Better dynamic linking support in SunOS
8921 Reading symbols from shared libraries which contain debugging symbols
8922 now works properly. However, there remain issues such as automatic
8923 skipping of `transfer vector' code during function calls, which
8924 make it harder to debug code in a shared library, than to debug the
8925 same code linked statically.
8929 GDB is now using the latest `getopt' routines from the FSF. This
8930 version accepts the -- prefix for options with long names. GDB will
8931 continue to accept the old forms (-option and +option) as well.
8932 Various single letter abbreviations for options have been explicity
8933 added to the option table so that they won't get overshadowed in the
8934 future by other options that begin with the same letter.
8938 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8939 Many assorted bugs have been handled. Many more remain to be handled.
8940 See the various ChangeLog files (primarily in gdb and bfd) for details.
8943 *** Changes in GDB-4.3:
8945 * New machines supported (host and target)
8947 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8948 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8949 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8951 * Almost SCO Unix support
8953 We had hoped to support:
8954 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8955 (except for core file support), but we discovered very late in the release
8956 that it has problems with process groups that render gdb unusable. Sorry
8957 about that. I encourage people to fix it and post the fixes.
8959 * Preliminary ELF and DWARF support
8961 GDB can read ELF object files on System V Release 4, and can handle
8962 debugging records for C, in DWARF format, in ELF files. This support
8963 is preliminary. If you bring up GDB on another SVR4 system, please
8964 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8969 GDB now uses the latest `readline' library. One user-visible change
8970 is that two tabs will list possible command completions, which previously
8971 required typing M-? (meta-question mark, or ESC ?).
8975 The `stepi' bug that many of you noticed has been squashed.
8976 Many bugs in C++ have been handled. Many more remain to be handled.
8977 See the various ChangeLog files (primarily in gdb and bfd) for details.
8979 * State of the MIPS world (in case you wondered):
8981 GDB can understand the symbol tables emitted by the compilers
8982 supplied by most vendors of MIPS-based machines, including DEC. These
8983 symbol tables are in a format that essentially nobody else uses.
8985 Some versions of gcc come with an assembler post-processor called
8986 mips-tfile. This program is required if you want to do source-level
8987 debugging of gcc-compiled programs. I believe FSF does not ship
8988 mips-tfile with gcc version 1, but it will eventually come with gcc
8991 Debugging of g++ output remains a problem. g++ version 1.xx does not
8992 really support it at all. (If you're lucky, you should be able to get
8993 line numbers and stack traces to work, but no parameters or local
8994 variables.) With some work it should be possible to improve the
8997 When gcc version 2 is released, you will have somewhat better luck.
8998 However, even then you will get confusing results for inheritance and
9001 We will eventually provide full debugging of g++ output on
9002 DECstations. This will probably involve some kind of stabs-in-ecoff
9003 encapulation, but the details have not been worked out yet.
9006 *** Changes in GDB-4.2:
9008 * Improved configuration
9010 Only one copy of `configure' exists now, and it is not self-modifying.
9011 Porting BFD is simpler.
9015 The `step' and `next' commands now only stop at the first instruction
9016 of a source line. This prevents the multiple stops that used to occur
9017 in switch statements, for-loops, etc. `Step' continues to stop if a
9018 function that has debugging information is called within the line.
9022 Lots of small bugs fixed. More remain.
9024 * New host supported (not target)
9026 Intel 386 PC clone running Mach i386-none-mach
9029 *** Changes in GDB-4.1:
9031 * Multiple source language support
9033 GDB now has internal scaffolding to handle several source languages.
9034 It determines the type of each source file from its filename extension,
9035 and will switch expression parsing and number formatting to match the
9036 language of the function in the currently selected stack frame.
9037 You can also specifically set the language to be used, with
9038 `set language c' or `set language modula-2'.
9042 GDB now has preliminary support for the GNU Modula-2 compiler,
9043 currently under development at the State University of New York at
9044 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
9045 continue through the fall of 1991 and into 1992.
9047 Other Modula-2 compilers are currently not supported, and attempting to
9048 debug programs compiled with them will likely result in an error as the
9049 symbol table is read. Feel free to work on it, though!
9051 There are hooks in GDB for strict type checking and range checking,
9052 in the `Modula-2 philosophy', but they do not currently work.
9056 GDB can now write to executable and core files (e.g. patch
9057 a variable's value). You must turn this switch on, specify
9058 the file ("exec foo" or "core foo"), *then* modify it, e.g.
9059 by assigning a new value to a variable. Modifications take
9062 * Automatic SunOS shared library reading
9064 When you run your program, GDB automatically determines where its
9065 shared libraries (if any) have been loaded, and reads their symbols.
9066 The `share' command is no longer needed. This also works when
9067 examining core files.
9071 You can specify the number of lines that the `list' command shows.
9074 * New machines supported (host and target)
9076 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
9077 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
9078 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
9080 * New hosts supported (not targets)
9082 IBM RT/PC: romp-ibm-aix or rtpc
9084 * New targets supported (not hosts)
9086 AMD 29000 embedded with COFF a29k-none-coff
9087 AMD 29000 embedded with a.out a29k-none-aout
9088 Ultracomputer remote kernel debug a29k-nyu-kern
9090 * New remote interfaces
9096 *** Changes in GDB-4.0:
9100 Wide output is wrapped at good places to make the output more readable.
9102 Gdb now supports cross-debugging from a host machine of one type to a
9103 target machine of another type. Communication with the target system
9104 is over serial lines. The ``target'' command handles connecting to the
9105 remote system; the ``load'' command will download a program into the
9106 remote system. Serial stubs for the m68k and i386 are provided. Gdb
9107 also supports debugging of realtime processes running under VxWorks,
9108 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
9109 stub on the target system.
9111 New CPUs supported include the AMD 29000 and Intel 960.
9113 GDB now reads object files and symbol tables via a ``binary file''
9114 library, which allows a single copy of GDB to debug programs of multiple
9115 object file types such as a.out and coff.
9117 There is now a GDB reference card in "doc/refcard.tex". (Make targets
9118 refcard.dvi and refcard.ps are available to format it).
9121 * Control-Variable user interface simplified
9123 All variables that control the operation of the debugger can be set
9124 by the ``set'' command, and displayed by the ``show'' command.
9126 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
9127 ``Show prompt'' produces the response:
9128 Gdb's prompt is new-gdb=>.
9130 What follows are the NEW set commands. The command ``help set'' will
9131 print a complete list of old and new set commands. ``help set FOO''
9132 will give a longer description of the variable FOO. ``show'' will show
9133 all of the variable descriptions and their current settings.
9135 confirm on/off: Enables warning questions for operations that are
9136 hard to recover from, e.g. rerunning the program while
9137 it is already running. Default is ON.
9139 editing on/off: Enables EMACS style command line editing
9140 of input. Previous lines can be recalled with
9141 control-P, the current line can be edited with control-B,
9142 you can search for commands with control-R, etc.
9145 history filename NAME: NAME is where the gdb command history
9146 will be stored. The default is .gdb_history,
9147 or the value of the environment variable
9150 history size N: The size, in commands, of the command history. The
9151 default is 256, or the value of the environment variable
9154 history save on/off: If this value is set to ON, the history file will
9155 be saved after exiting gdb. If set to OFF, the
9156 file will not be saved. The default is OFF.
9158 history expansion on/off: If this value is set to ON, then csh-like
9159 history expansion will be performed on
9160 command line input. The default is OFF.
9162 radix N: Sets the default radix for input and output. It can be set
9163 to 8, 10, or 16. Note that the argument to "radix" is interpreted
9164 in the current radix, so "set radix 10" is always a no-op.
9166 height N: This integer value is the number of lines on a page. Default
9167 is 24, the current `stty rows'' setting, or the ``li#''
9168 setting from the termcap entry matching the environment
9171 width N: This integer value is the number of characters on a line.
9172 Default is 80, the current `stty cols'' setting, or the ``co#''
9173 setting from the termcap entry matching the environment
9176 Note: ``set screensize'' is obsolete. Use ``set height'' and
9177 ``set width'' instead.
9179 print address on/off: Print memory addresses in various command displays,
9180 such as stack traces and structure values. Gdb looks
9181 more ``symbolic'' if you turn this off; it looks more
9182 ``machine level'' with it on. Default is ON.
9184 print array on/off: Prettyprint arrays. New convenient format! Default
9187 print demangle on/off: Print C++ symbols in "source" form if on,
9190 print asm-demangle on/off: Same, for assembler level printouts
9193 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
9196 * Support for Epoch Environment.
9198 The epoch environment is a version of Emacs v18 with windowing. One
9199 new command, ``inspect'', is identical to ``print'', except that if you
9200 are running in the epoch environment, the value is printed in its own
9204 * Support for Shared Libraries
9206 GDB can now debug programs and core files that use SunOS shared libraries.
9207 Symbols from a shared library cannot be referenced
9208 before the shared library has been linked with the program (this
9209 happens after you type ``run'' and before the function main() is entered).
9210 At any time after this linking (including when examining core files
9211 from dynamically linked programs), gdb reads the symbols from each
9212 shared library when you type the ``sharedlibrary'' command.
9213 It can be abbreviated ``share''.
9215 sharedlibrary REGEXP: Load shared object library symbols for files
9216 matching a unix regular expression. No argument
9217 indicates to load symbols for all shared libraries.
9219 info sharedlibrary: Status of loaded shared libraries.
9224 A watchpoint stops execution of a program whenever the value of an
9225 expression changes. Checking for this slows down execution
9226 tremendously whenever you are in the scope of the expression, but is
9227 quite useful for catching tough ``bit-spreader'' or pointer misuse
9228 problems. Some machines such as the 386 have hardware for doing this
9229 more quickly, and future versions of gdb will use this hardware.
9231 watch EXP: Set a watchpoint (breakpoint) for an expression.
9233 info watchpoints: Information about your watchpoints.
9235 delete N: Deletes watchpoint number N (same as breakpoints).
9236 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
9237 enable N: Re-enables watchpoint number N (same as breakpoints).
9240 * C++ multiple inheritance
9242 When used with a GCC version 2 compiler, GDB supports multiple inheritance
9245 * C++ exception handling
9247 Gdb now supports limited C++ exception handling. Besides the existing
9248 ability to breakpoint on an exception handler, gdb can breakpoint on
9249 the raising of an exception (before the stack is peeled back to the
9252 catch FOO: If there is a FOO exception handler in the dynamic scope,
9253 set a breakpoint to catch exceptions which may be raised there.
9254 Multiple exceptions (``catch foo bar baz'') may be caught.
9256 info catch: Lists all exceptions which may be caught in the
9257 current stack frame.
9260 * Minor command changes
9262 The command ``call func (arg, arg, ...)'' now acts like the print
9263 command, except it does not print or save a value if the function's result
9264 is void. This is similar to dbx usage.
9266 The ``up'' and ``down'' commands now always print the frame they end up
9267 at; ``up-silently'' and `down-silently'' can be used in scripts to change
9268 frames without printing.
9270 * New directory command
9272 'dir' now adds directories to the FRONT of the source search path.
9273 The path starts off empty. Source files that contain debug information
9274 about the directory in which they were compiled can be found even
9275 with an empty path; Sun CC and GCC include this information. If GDB can't
9276 find your source file in the current directory, type "dir .".
9278 * Configuring GDB for compilation
9280 For normal use, type ``./configure host''. See README or gdb.texinfo
9283 GDB now handles cross debugging. If you are remotely debugging between
9284 two different machines, type ``./configure host -target=targ''.
9285 Host is the machine where GDB will run; targ is the machine
9286 where the program that you are debugging will run.