1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 14
6 * The MPX commands "show/set mpx bound" have been deprecated, as Intel
7 listed MPX as removed in 2019.
9 * Building GDB and GDBserver now requires a C++17 compiler.
10 For example, GCC 9 or later.
12 * GDB index now contains information about the main function. This speeds up
13 startup when it is being used for some large binaries.
15 * On hosts where threading is available, DWARF reading is now done in
16 the background, resulting in faster startup. This can be controlled
17 using "maint set dwarf synchronous".
22 Attempting to use both the 'r' and 'b' flags with the disassemble
23 command will now give an error. Previously the 'b' flag would
24 always override the 'r' flag.
26 maintenance info line-table
27 Add an EPILOGUE-BEGIN column to the output of the command. It indicates
28 if the line is considered the start of the epilgoue, and thus a point at
29 which the frame can be considered destroyed.
33 info missing-debug-handler
34 List all the registered missing debug handlers.
36 enable missing-debug-handler LOCUS HANDLER
37 disable missing-debug-handler LOCUS HANDLER
38 Enable or disable a missing debug handler with a name matching the
39 regular expression HANDLER, in LOCUS.
41 LOCUS can be 'global' to operate on global missing debug handler,
42 'progspace' to operate on handlers within the current program space,
43 or can be a regular expression which is matched against the filename
44 of the primary executable in each program space.
46 maintenance info linux-lwps
47 List all LWPs under control of the linux-nat target.
49 set remote thread-options-packet
50 show remote thread-options-packet
51 Set/show the use of the thread options packet.
53 * New features in the GDB remote stub, GDBserver
55 ** The --remote-debug and --event-loop-debug command line options
58 ** The --debug command line option now takes an optional comma
59 separated list of components to emit debug for. The currently
60 supported components are: all, threads, event-loop, and remote.
61 If no components are given then threads is assumed.
63 ** The 'monitor set remote-debug' and 'monitor set event-loop-debug'
64 command have been removed.
66 ** The 'monitor set debug 0|1' command has been extended to take a
67 component name, e.g.: 'monitor set debug COMPONENT off|on'.
68 Possible component names are: all, threads, event-loop, and
73 ** New function gdb.notify_mi(NAME, DATA), that emits custom
74 GDB/MI async notification.
76 ** New read/write attribute gdb.Value.bytes that contains a bytes
77 object holding the contents of this value.
79 ** New module gdb.missing_debug that facilitates dealing with
80 objfiles that are missing any debug information.
82 ** New function gdb.missing_debug.register_handler that can register
83 an instance of a sub-class of gdb.missing_debug.MissingDebugInfo
84 as a handler for objfiles that are missing debug information.
86 ** New class gdb.missing_debug.MissingDebugInfo which can be
87 sub-classed to create handlers for objfiles with missing debug
90 ** Stop events now have a "details" attribute that holds a
91 dictionary that carries the same information as an MI "*stopped"
94 ** New function gdb.interrupt(), that interrupts GDB as if the user
97 ** New gdb.InferiorThread.ptid_string attribute. This read-only
98 attribute contains the string that appears in the 'Target Id'
99 column of the 'info threads' command output.
101 ** It is no longer possible to create new gdb.Progspace object using
102 'gdb.Progspace()', this will result in a TypeError. Progspace
103 objects can still be obtained through calling other API
104 functions, for example 'gdb.current_progspace()'.
106 ** User defined attributes can be added to a gdb.Inferior object,
107 these will be stored in the object's new Inferior.__dict__
110 ** User defined attributes can be added to a gdb.InferiorThread
111 object, these will be stored in the object's new
112 InferiorThread.__dict__ attribute.
114 ** New constants gdb.SYMBOL_TYPE_DOMAIN, gdb.SYMBOL_FUNCTION_DOMAIN,
115 and gdb.SEARCH_*_DOMAIN corresponding to all the existing symbol
116 domains. Symbol lookup can now search in multiple domains at
117 once, and can also narrowly search for just a type or function.
119 * Debugger Adapter Protocol changes
121 ** GDB now emits the "process" event.
123 ** GDB now supports the "cancel" request.
125 ** The "attach" request now supports specifying the program.
127 ** New command "set debug dap-log-level" controls DAP logging.
129 ** The "set debug dap-log-file" command is now documented. This
130 command was available in GDB 14 but not documented.
134 ** New constants SYMBOL_TYPE_DOMAIN, SYMBOL_FUNCTION_DOMAIN, and
135 SEARCH_*_DOMAIN corresponding to all the existing symbol domains.
136 Symbol lookup can now search in multiple domains at once, and can
137 also narrowly search for just a type or function.
141 New stop reason: clone
142 Indicates that a clone system call was executed.
145 Enable/disable optional event reporting, on a per-thread basis.
146 Currently supported options are GDB_THREAD_OPTION_CLONE, to enable
147 clone event reporting, and GDB_THREAD_OPTION_EXIT to enable thread
148 exit event reporting.
150 QThreadOptions in qSupported
151 The qSupported packet allows GDB to inform the stub it supports the
152 QThreadOptions packet, and the qSupported response can contain the
153 set of thread options the remote stub supports.
155 *** Changes in GDB 14
157 * GDB now supports the AArch64 Scalable Matrix Extension 2 (SME2), which
158 includes a new 512 bit lookup table register named ZT0.
160 * GDB now supports the AArch64 Scalable Matrix Extension (SME), which includes
161 a new matrix register named ZA, a new thread register TPIDR2 and a new vector
162 length register SVG (streaming vector granule). GDB also supports tracking
163 ZA state across signal frames.
165 Some features are still under development or are dependent on ABI specs that
166 are still in alpha stage. For example, manual function calls with ZA state
167 don't have any special handling, and tracking of SVG changes based on
168 DWARF information is still not implemented, but there are plans to do so in
171 * GDB now recognizes the NO_COLOR environment variable and disables
172 styling according to the spec. See https://no-color.org/.
173 Styling can be re-enabled with "set style enabled on".
175 * The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
176 has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
179 * GDB now has some support for integer types larger than 64 bits.
181 * Removed targets and native configurations
183 GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
184 AIX version is now AIX 7.1.
186 * Multi-target feature configuration
188 GDB now supports the individual configuration of remote targets' feature
189 sets. Based on the current selection of a target, the commands 'set remote
190 <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
191 configure a target's feature packet and to display its configuration,
194 The individual packet sizes can be configured and shown using the commands
195 ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
196 ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
197 ** 'show remote memory-read-packet-size'
198 ** 'show remote memory-write-packet-size'.
200 The configuration of the packet itself, as well as the size of a memory-read
201 or memory-write packet applies to the currently selected target (if
202 available). If no target is selected, it applies to future remote
203 connections. Similarly, the show commands print the configuration of the
204 currently selected target. If no remote target is selected, the default
205 configuration for future connections is shown.
207 * GDB has initial built-in support for the Debugger Adapter Protocol.
208 This support requires that GDB be built with Python scripting
211 * For the break command, multiple uses of the 'thread' or 'task'
212 keywords will now give an error instead of just using the thread or
213 task id from the last instance of the keyword. E.g.:
214 break foo thread 1 thread 2
215 will now give an error rather than using 'thread 2'.
217 * For the watch command, multiple uses of the 'task' keyword will now
218 give an error instead of just using the task id from the last
219 instance of the keyword. E.g.:
220 watch my_var task 1 task 2
221 will now give an error rather than using 'task 2'. The 'thread'
222 keyword already gave an error when used multiple times with the
223 watch command, this remains unchanged.
225 * The 'set print elements' setting now helps when printing large arrays.
226 If an array would otherwise exceed max-value-size, but 'print elements'
227 is set such that the size of elements to print is less than or equal
228 to 'max-value-size', GDB will now still print the array, however only
229 'max-value-size' worth of data will be added into the value history.
231 * For both the break and watch commands, it is now invalid to use both
232 the 'thread' and 'task' keywords within the same command. For
233 example the following commnds will now give an error:
234 break foo thread 1 task 1
235 watch var thread 2 task 3
237 * The printf command now accepts a '%V' output format which will
238 format an expression just as the 'print' command would. Print
239 options can be placed withing '[...]' after the '%V' to modify how
240 the value is printed. E.g:
241 printf "%V", some_array
242 printf "%V[-array-indexes on]", some_array
243 will print the array without, or with array indexes included, just
244 as the array would be printed by the 'print' command. This
245 functionality is also available for dprintf when dprintf-style is
248 * When the printf command requires a string to be fetched from the
249 inferior, GDB now uses the existing 'max-value-size' setting to the
250 limit the memory allocated within GDB. The default 'max-value-size'
251 is 64k. To print longer strings you should increase
254 * The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
256 * The Ada 2022 target name symbol ('@') is now supported by the Ada
259 * The 'list' command now accepts '.' as an argument, which tells GDB to
260 print the location around the point of execution within the current frame.
261 If the inferior hasn't started yet, the command will print around the
262 beginning of the 'main' function.
264 * Using the 'list' command with no arguments in a situation where the
265 command would attempt to list past the end of the file now warns the
266 user that the end of file has been reached, refers the user to the
267 newly added '.' argument
269 * Breakpoints can now be inferior-specific. This is similar to the
270 existing thread-specific breakpoint support. Breakpoint conditions
271 can include the 'inferior' keyword followed by an inferior id (as
272 displayed in the 'info inferiors' output). It is invalid to use the
273 'inferior' keyword with either the 'thread' or 'task' keywords when
274 creating a breakpoint.
276 * New convenience function "$_shell", to execute a shell command and
277 return the result. This lets you run shell commands in expressions.
280 (gdb) p $_shell("true")
282 (gdb) p $_shell("false")
284 (gdb) break func if $_shell("some command") == 0
288 --additional-debug-dirs=PATHs
290 Provide a colon-separated list of additional directories to search for
291 separate debug info. These directories are added to the default value of
292 the 'debug-file-directory' GDB parameter.
296 set debug breakpoint on|off
297 show debug breakpoint
298 Print additional debug messages about breakpoint insertion and removal.
300 maintenance print record-instruction [ N ]
301 Print the recorded information for a given instruction. If N is not given
302 prints how GDB would undo the last instruction executed. If N is negative,
303 prints how GDB would undo the N-th previous instruction, and if N is
304 positive, it prints how GDB will redo the N-th following instruction.
306 maintenance info frame-unwinders
307 List the frame unwinders currently in effect, starting with the highest
310 maintenance wait-for-index-cache
311 Wait until all pending writes to the index cache have completed.
313 set always-read-ctf on|off
315 When off, CTF is only read if DWARF is not present. When on, CTF is
316 read regardless of whether DWARF is present. Off by default.
319 Get main symbol to identify entry point into program.
321 set tui mouse-events [on|off]
322 show tui mouse-events
323 When on (default), mouse clicks control the TUI and can be accessed by
324 Python extensions. When off, mouse clicks are handled by the terminal,
325 enabling terminal-native text selection.
329 ** MI version 1 has been removed.
331 ** mi now reports 'no-history' as a stop reason when hitting the end of the
332 reverse execution history.
334 ** When creating a thread-specific breakpoint using the '-p' option,
335 the -break-insert command would report the 'thread' field twice in
336 the reply. The content of both fields was always identical. This
337 has now been fixed; the 'thread' field will be reported just once
338 for thread-specific breakpoints, or not at all for breakpoints
339 without a thread restriction. The same is also true for the 'task'
340 field of an Ada task-specific breakpoint.
342 ** It is no longer possible to create a thread-specific breakpoint for
343 a thread that doesn't exist using '-break-insert -p ID'. Creating
344 breakpoints for non-existent threads is not allowed when using the
345 CLI, that the MI allowed it was a long standing bug, which has now
348 ** The '--simple-values' argument to the '-stack-list-arguments',
349 '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
350 commands now takes reference types into account: that is, a value is now
351 considered simple if it is neither an array, structure, or union, nor a
352 reference to an array, structure, or union. (Previously all references were
353 considered simple.) Support for this feature can be verified by using the
354 '-list-features' command, which should contain "simple-values-ref-types".
356 ** The -break-insert command now accepts a '-g thread-group-id' option
357 to allow for the creation of inferior-specific breakpoints.
359 ** The bkpt tuple, which appears in breakpoint-created notifications,
360 and in the result of the -break-insert command can now include an
361 optional 'inferior' field for both the main breakpoint, and each
362 location, when the breakpoint is inferior-specific.
366 ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
368 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
370 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
371 now be of type 'str' otherwise a TypeError will be raised.
373 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
374 values of type 'bool'. Changing this attribute will now
375 invalidate GDB's frame-cache, which means GDB will need to
376 rebuild its frame-cache when next required - either with, or
377 without the particular unwinder, depending on how 'enabled' was
380 ** New methods added to the gdb.PendingFrame class. These methods
381 have the same behaviour as the corresponding methods on
382 gdb.Frame. The new methods are:
384 - gdb.PendingFrame.name: Return the name for the frame's
386 - gdb.PendingFrame.is_valid: Return True if the pending frame
388 - gdb.PendingFrame.pc: Return the $pc register value for this
390 - gdb.PendingFrame.language: Return a string containing the
391 language for this frame, or None.
392 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
393 object for the current location within the pending frame, or
395 - gdb.PendingFrame.block: Return a gdb.Block for the current
396 pending frame, or None.
397 - gdb.PendingFrame.function: Return a gdb.Symbol for the
398 current pending frame, or None.
400 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
401 now use either an integer or a gdb.Value object for each of its
402 'sp', 'pc', and 'special' attributes.
404 ** A new class gdb.unwinder.FrameId has been added. Instances of
405 this class are constructed with 'sp' (stack-pointer) and 'pc'
406 (program-counter) values, and can be used as the frame-id when
407 calling gdb.PendingFrame.create_unwind_info.
409 ** It is now no longer possible to sub-class the
410 gdb.disassembler.DisassemblerResult type.
412 ** The Disassembler API from the gdb.disassembler module has been
413 extended to include styling support:
415 - The DisassemblerResult class can now be initialized with a list
416 of parts. Each part represents part of the disassembled
417 instruction along with the associated style information. This
418 list of parts can be accessed with the new
419 DisassemblerResult.parts property.
421 - New constants gdb.disassembler.STYLE_* representing all the
422 different styles part of an instruction might have.
424 - New methods DisassembleInfo.text_part and
425 DisassembleInfo.address_part which are used to create the new
426 styled parts of a disassembled instruction.
428 - Changes are backwards compatible, the older API can still be
429 used to disassemble instructions without styling.
431 ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
432 GDB/MI command and returns the output as a Python dictionary.
434 ** New function gdb.block_signals(). This returns a context manager
435 that blocks any signals that GDB needs to handle itself.
437 ** New class gdb.Thread. This is a subclass of threading.Thread
438 that calls gdb.block_signals in its "start" method.
440 ** gdb.parse_and_eval now has a new "global_context" parameter.
441 This can be used to request that the parse only examine global
444 ** gdb.Inferior now has a new "arguments" attribute. This holds the
445 command-line arguments to the inferior, if known.
447 ** gdb.Inferior now has a new "main_name" attribute. This holds the
448 name of the inferior's "main", if known.
450 ** gdb.Inferior now has new methods "clear_env", "set_env", and
451 "unset_env". These can be used to modify the inferior's
452 environment before it is started.
454 ** gdb.Value now has the 'assign' method.
456 ** gdb.Value now has the 'to_array' method. This converts an
457 array-like Value to an array.
459 ** gdb.Progspace now has the new method "objfile_for_address". This
460 returns the gdb.Objfile, if any, that covers a given address.
462 ** gdb.Breakpoint now has an "inferior" attribute. If the
463 Breakpoint object is inferior specific then this attribute holds
464 the inferior-id (an integer). If the Breakpoint object is not
465 inferior specific, then this field contains None. This field can
468 ** gdb.Type now has the "is_array_like" and "is_string_like"
469 methods. These reflect GDB's internal idea of whether a type
470 might be array- or string-like, even if they do not have the
471 corresponding type code.
473 ** gdb.ValuePrinter is a new class that can be used as the base
474 class for the result of applying a pretty-printer. As a base
475 class, it signals to gdb that the printer may implement new
476 pretty-printer methods.
478 ** New attribute Progspace.symbol_file. This attribute holds the
479 gdb.Objfile that corresponds to Progspace.filename (when
480 Progspace.filename is not None), otherwise, this attribute is
483 ** New attribute Progspace.executable_filename. This attribute
484 holds a string containing a file name set by the "exec-file" or
485 "file" commands, or None if no executable file is set. This
486 isn't the exact string passed by the user to these commands; the
487 file name will have been partially resolved to an absolute file
490 ** A new executable_changed event registry is available. This event
491 emits ExecutableChangedEvent objects, which have 'progspace' (a
492 gdb.Progspace) and 'reload' (a Boolean) attributes. This event
493 is emitted when gdb.Progspace.executable_filename changes.
495 ** New event registries gdb.events.new_progspace and
496 gdb.events.free_progspace, these emit NewProgspaceEvent and
497 FreeProgspaceEvent event types respectively. Both of these event
498 types have a single 'progspace' attribute, which is the
499 gdb.Progspace that is either being added to GDB, or removed from
502 ** gdb.LazyString now implements the __str__ method.
504 ** New method gdb.Frame.static_link that returns the outer frame
505 of a nested function frame.
507 *** Changes in GDB 13
509 * MI version 1 is deprecated, and will be removed in GDB 14.
511 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
512 reading memory tag data for AArch64 MTE from core files generated by
513 the gcore command or the Linux kernel.
515 When a process uses memory-mapped pages protected by memory tags (for
516 example, AArch64 MTE), this additional information will be recorded in
517 the core file in the event of a crash or if GDB generates a core file
518 from the current process state. GDB will show this additional information
519 automatically, or through one of the memory-tag subcommands.
521 * Scheduler-locking and new threads
523 When scheduler-locking is in effect, only the current thread may run
524 when the inferior is resumed. However, previously, new threads
525 created by the resumed thread would still be able to run free. Now,
526 they are held stopped.
528 * "info breakpoints" now displays enabled breakpoint locations of
529 disabled breakpoints as in the "y-" state. For example:
531 (gdb) info breakpoints
532 Num Type Disp Enb Address What
533 1 breakpoint keep n <MULTIPLE>
534 1.1 y- 0x00000000000011b6 in ...
535 1.2 y- 0x00000000000011c2 in ...
536 1.3 n 0x00000000000011ce in ...
538 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
539 aarch64 architectures.
541 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
543 * Remove support for building against Python 2, it is now only possible to
544 build GDB against Python 3.
546 * DBX mode has been removed.
548 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
549 emit to indicate where a breakpoint should be placed to break in a function
552 * Completion now also offers "NUMBER" for "set" commands that accept
553 a numeric argument and the "unlimited" keyword. For example:
555 (gdb) set width <TAB>
560 (gdb) complete set width
564 * Disassembler styling using libopcodes. GDB now supports
565 disassembler styling using libopcodes. This is only available for
566 some targets (currently x86 and RISC-V). For unsupported targets
567 Python Pygments is still used. For supported targets, libopcodes
568 styling is used by default.
570 * The Windows native target now supports target async.
572 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
574 * The format of 'disassemble /r' and 'record instruction-history /r'
575 has changed. The instruction bytes could now be grouped together,
576 and displayed in the endianness of the instruction. This is the
577 same layout as used by GNU objdump when disassembling.
579 There is now 'disassemble /b' and 'record instruction-history /b'
580 which will always display the instructions bytes one at a time in
581 memory order, that is, the byte at the lowest address first.
583 For both /r and /b GDB is now better at using whitespace in order to
584 align the disassembled instruction text.
586 * The TUI no longer styles the source and assembly code highlighted by
587 the current position indicator by default. You can however
588 re-enable styling using the new "set style tui-current-position"
591 * New convenience variable $_inferior_thread_count contains the number
592 of live threads in the current inferior.
594 * When a breakpoint with multiple code locations is hit, GDB now prints
595 the code location using the syntax <breakpoint_number>.<location_number>
597 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
599 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
600 and $_hit_locno to the hit breakpoint number and code location number.
601 This allows to disable the last hit breakpoint using
602 (gdb) disable $_hit_bpnum
603 or disable only the specific breakpoint code location using
604 (gdb) disable $_hit_bpnum.$_hit_locno
605 These commands can be used inside the command list of a breakpoint to
606 automatically disable the just encountered breakpoint (or the just
607 encountered specific breakpoint code location).
608 When a breakpoint has only one location, $_hit_locno is set to 1 so that
609 (gdb) disable $_hit_bpnum.$_hit_locno
611 (gdb) disable $_hit_bpnum
612 are both disabling the breakpoint.
616 maintenance set ignore-prologue-end-flag on|off
617 maintenance show ignore-prologue-end-flag
618 This setting, which is off by default, controls whether GDB ignores the
619 PROLOGUE-END flag from the line-table when skipping prologue. This can be
620 used to force GDB to use prologue analyzers if the line-table is constructed
621 from erroneous debug information.
623 set print nibbles [on|off]
625 This controls whether the 'print/t' command will display binary values
626 in groups of four bits, known as "nibbles". The default is 'off'.
628 maintenance set libopcodes-styling on|off
629 maintenance show libopcodes-styling
630 These can be used to force off libopcodes based styling, the Python
631 Pygments styling will then be used instead.
633 set style disassembler comment
634 show style disassembler comment
635 set style disassembler immediate
636 show style disassembler immediate
637 set style disassembler mnemonic
638 show style disassembler mnemonic
639 set style disassembler register
640 show style disassembler register
641 set style disassembler address
642 show style disassembler address
643 set style disassembler symbol
644 show style disassembler symbol
645 For targets that support libopcodes based styling, these settings
646 control how various aspects of the disassembler output are styled.
647 The 'disassembler address' and 'disassembler symbol' styles are
648 aliases for the 'address' and 'function' styles respectively.
650 maintenance print frame-id [ LEVEL ]
651 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
652 not given, then print the frame-id for the currently selected frame.
654 set debug infcall on|off
656 Print additional debug messages about inferior function calls.
658 set debug solib on|off
660 Print additional debug messages about shared library handling.
662 set style tui-current-position [on|off]
663 Whether to style the source and assembly code highlighted by the
664 TUI's current position indicator. The default is off.
666 set print characters LIMIT
667 show print characters
668 This new setting is like 'set print elements', but controls how many
669 characters of a string are printed. This functionality used to be
670 covered by 'set print elements', but it can be controlled separately
671 now. LIMIT can be set to a numerical value to request that particular
672 character count, to 'unlimited' to print all characters of a string,
673 or to 'elements', which is also the default, to follow the setting of
674 'set print elements' as it used to be.
676 print -characters LIMIT
677 This new option to the 'print' command has the same effect as a temporary
678 use of 'set print characters'.
682 document user-defined
683 It is now possible to document user-defined aliases.
684 When a user-defined alias is documented, the help and apropos commands
685 use the provided documentation instead of the documentation of the
687 Documenting a user-defined alias is particularly useful when the alias
688 is a set of nested 'with' commands to avoid showing the help of
689 the with command for an alias that will in fact launch the
690 last command given in the nested commands.
692 maintenance info line-table
693 Add a PROLOGUE-END column to the output which indicates that an
694 entry corresponds to an address where a breakpoint should be placed
695 to be at the first instruction past a function's prologue.
699 set debug aix-solib on|off
701 set debug solib-frv on|off
703 Removed in favor of "set/show debug solib".
705 maintenance info program-spaces
706 This command now includes a 'Core File' column which indicates the
707 name of the core file associated with each program space.
711 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
713 GNU/Linux/CSKY (gdbserver) csky*-*linux*
719 ** The async record stating the stopped reason 'breakpoint-hit' now
720 contains an optional field locno giving the code location number
721 when the breakpoint has multiple code locations.
725 ** GDB will now reformat the doc string for gdb.Command and
726 gdb.Parameter sub-classes to remove unnecessary leading
727 whitespace from each line before using the string as the help
730 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
731 that formats ADDRESS as 'address <symbol+offset>', where symbol is
732 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
733 This is the same format that GDB uses when printing address, symbol,
734 and offset information from the disassembler.
736 ** New function gdb.current_language that returns the name of the
737 current language. Unlike gdb.parameter('language'), this will
740 ** New method gdb.Frame.language that returns the name of the
743 ** New Python API for wrapping GDB's disassembler:
745 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
746 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
747 ARCH is either None or a string containing a bfd architecture
748 name. DISASSEMBLER is registered as a disassembler for
749 architecture ARCH, or for all architectures if ARCH is None.
750 The previous disassembler registered for ARCH is returned, this
751 can be None if no previous disassembler was registered.
753 - gdb.disassembler.Disassembler is the class from which all
754 disassemblers should inherit. Its constructor takes a string,
755 a name for the disassembler, which is currently only used in
756 some debug output. Sub-classes should override the __call__
757 method to perform disassembly, invoking __call__ on this base
758 class will raise an exception.
760 - gdb.disassembler.DisassembleInfo is the class used to describe
761 a single disassembly request from GDB. An instance of this
762 class is passed to the __call__ method of
763 gdb.disassembler.Disassembler and has the following read-only
764 attributes: 'address', and 'architecture', as well as the
765 following method: 'read_memory'.
767 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
768 calls GDB's builtin disassembler on INFO, which is a
769 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
770 optional, its default value is None. If MEMORY_SOURCE is not
771 None then it must be an object that has a 'read_memory' method.
773 - gdb.disassembler.DisassemblerResult is a class that can be used
774 to wrap the result of a call to a Disassembler. It has
775 read-only attributes 'length' and 'string'.
777 ** gdb.Objfile now has an attribute named "is_file". This is True
778 if the objfile comes from a file, and False otherwise.
780 ** New function gdb.print_options that returns a dictionary of the
781 prevailing print options, in the form accepted by
782 gdb.Value.format_string.
784 ** gdb.Value.format_string now uses the format provided by 'print',
785 if it is called during a 'print' or other similar operation.
787 ** gdb.Value.format_string now accepts the 'summary' keyword. This
788 can be used to request a shorter representation of a value, the
789 way that 'set print frame-arguments scalars' does.
791 ** New Python type gdb.BreakpointLocation.
792 The new attribute 'locations' of gdb.Breakpoint returns a list of
793 gdb.BreakpointLocation objects specifying the locations where the
794 breakpoint is inserted into the debuggee.
796 ** The gdb.register_window_type method now restricts the set of
797 acceptable window names. The first character of a window's name
798 must start with a character in the set [a-zA-Z], every subsequent
799 character of a window's name must be in the set [-_.a-zA-Z0-9].
801 * New features in the GDB remote stub, GDBserver
803 ** GDBserver is now supported on LoongArch GNU/Linux.
805 ** GDBserver is now supported on CSKY GNU/Linux.
807 * LoongArch floating-point support
809 GDB now supports floating-point on LoongArch GNU/Linux.
811 * AMD GPU ROCm debugging support
813 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
816 *** Changes in GDB 12
818 * DBX mode is deprecated, and will be removed in GDB 13
820 * GDB 12 is the last release of GDB that will support building against
821 Python 2. From GDB 13, it will only be possible to build GDB itself
822 with Python 3 support.
824 * The disable-randomization setting now works on Windows.
826 * Improved C++ template support
828 GDB now treats functions/types involving C++ templates like it does function
829 overloads. Users may omit parameter lists to set breakpoints on families of
830 template functions, including types/functions composed of multiple template types:
832 (gdb) break template_func(template_1, int)
834 The above will set breakpoints at every function `template_func' where
835 the first function parameter is any template type named `template_1' and
836 the second function parameter is `int'.
838 TAB completion also gains similar improvements.
840 * The FreeBSD native target now supports async mode.
846 Enable or disable multithreaded symbol loading. This is enabled
847 by default, but passing --disable-threading or --enable-threading=no
848 to configure will disable it.
850 Disabling this can cause a performance penalty when there are a lot of
851 symbols to load, but is useful for debugging purposes.
855 maint set backtrace-on-fatal-signal on|off
856 maint show backtrace-on-fatal-signal
857 This setting is 'on' by default. When 'on' GDB will print a limited
858 backtrace to stderr in the situation where GDB terminates with a
859 fatal signal. This only supported on some platforms where the
860 backtrace and backtrace_symbols_fd functions are available.
862 set source open on|off
864 This setting, which is on by default, controls whether GDB will try
865 to open source code files. Switching this off will stop GDB trying
866 to open and read source code files, which can be useful if the files
867 are located over a slow network connection.
871 These are now deprecated aliases for "set max-value-size" and
872 "show max-value-size".
874 task apply [all | TASK-IDS...] [FLAG]... COMMAND
875 Like "thread apply", but applies COMMAND to Ada tasks.
878 Watchpoints can now be restricted to a specific Ada task.
880 maint set internal-error backtrace on|off
881 maint show internal-error backtrace
882 maint set internal-warning backtrace on|off
883 maint show internal-warning backtrace
884 GDB can now print a backtrace of itself when it encounters either an
885 internal-error, or an internal-warning. This is on by default for
886 internal-error and off by default for internal-warning.
889 Deprecated and replaced by "set logging enabled on|off".
891 set logging enabled on|off
893 These commands set or show whether logging is enabled or disabled.
896 You can now exit GDB by using the new command "exit", in addition to
897 the existing "quit" command.
899 set debug threads on|off
901 Print additional debug messages about thread creation and deletion.
903 set debug linux-nat on|off
905 These new commands replaced the old 'set debug lin-lwp' and 'show
906 debug lin-lwp' respectively. Turning this setting on prints debug
907 messages relating to GDB's handling of native Linux inferiors.
909 maint flush source-cache
910 Flush the contents of the source code cache.
912 maint set gnu-source-highlight enabled on|off
913 maint show gnu-source-highlight enabled
914 Whether GDB should use the GNU Source Highlight library for adding
915 styling to source code. When off, the library will not be used, even
916 when available. When GNU Source Highlight isn't used, or can't add
917 styling to a particular source file, then the Python Pygments
918 library will be used instead.
920 set suppress-cli-notifications (on|off)
921 show suppress-cli-notifications
922 This controls whether printing the notifications is suppressed for CLI.
923 CLI notifications occur when you change the selected context
924 (i.e., the current inferior, thread and/or the frame), or when
925 the program being debugged stops (e.g., because of hitting a
926 breakpoint, completing source-stepping, an interrupt, etc.).
928 set style disassembler enabled on|off
929 show style disassembler enabled
930 If GDB is compiled with Python support, and the Python Pygments
931 package is available, then, when this setting is on, disassembler
932 output will have styling applied.
934 set ada source-charset
935 show ada source-charset
936 Set the character set encoding that is assumed for Ada symbols. Valid
937 values for this follow the values that can be passed to the GNAT
938 compiler via the '-gnati' option. The default is ISO-8859-1.
944 These are the new names for the old 'layout', 'focus', 'refresh',
945 and 'winheight' tui commands respectively. The old names still
946 exist as aliases to these new commands.
950 The new command 'tui window width', and the alias 'winwidth' allow
951 the width of a tui window to be adjusted when windows are laid out
956 Control the display of debug output about GDB's tui.
961 Printing of floating-point values with base-modifying formats like
962 /x has been changed to display the underlying bytes of the value in
963 the desired base. This was GDB's documented behavior, but was never
964 implemented correctly.
967 This command can now print a reply, if the reply includes
968 non-printable characters. Any non-printable characters are printed
969 as escaped hex, e.g. \x?? where '??' is replaces with the value of
970 the non-printable character.
973 The clone-inferior command now ensures that the TTY, CMD and ARGS
974 settings are copied from the original inferior to the new one.
975 All modifications to the environment variables done using the 'set
976 environment' or 'unset environment' commands are also copied to the new
979 set debug lin-lwp on|off
981 These commands have been removed from GDB. The new command 'set
982 debug linux-nat' and 'show debug linux-nat' should be used
986 This command now includes information about the width of the tui
987 windows in its output.
993 These commands are now aliases for the 'tui layout', 'tui focus',
994 'tui refresh', and 'tui window height' commands respectively.
996 * GDB's Ada parser now supports an extension for specifying the exact
997 byte contents of a floating-point literal. This can be useful for
998 setting floating-point registers to a precise value without loss of
999 precision. The syntax is an extension of the based literal syntax.
1000 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
1001 of the floating-point type, and the "f" is the marker for floating
1006 ** The '-add-inferior' with no option flags now inherits the
1007 connection of the current inferior, this restores the behaviour of
1008 GDB as it was prior to GDB 10.
1010 ** The '-add-inferior' command now accepts a '--no-connection'
1011 option, which causes the new inferior to start without a
1014 ** The default version of the MI interpreter is now 4 (-i=mi4).
1016 ** The "script" field in breakpoint output (which is syntactically
1017 incorrect in MI 3 and below) has changed in MI 4 to become a list.
1018 This affects the following commands and events:
1022 - =breakpoint-created
1023 - =breakpoint-modified
1025 The -fix-breakpoint-script-output command can be used to enable
1026 this behavior with previous MI versions.
1030 GNU/Linux/LoongArch loongarch*-*-linux*
1038 ** New function gdb.add_history(), which takes a gdb.Value object
1039 and adds the value it represents to GDB's history list. An
1040 integer, the index of the new item in the history list, is
1043 ** New function gdb.history_count(), which returns the number of
1044 values in GDB's value history.
1046 ** New gdb.events.gdb_exiting event. This event is called with a
1047 gdb.GdbExitingEvent object which has the read-only attribute
1048 'exit_code', which contains the value of the GDB exit code. This
1049 event is triggered once GDB decides it is going to exit, but
1050 before GDB starts to clean up its internal state.
1052 ** New function gdb.architecture_names(), which returns a list
1053 containing all of the possible Architecture.name() values. Each
1056 ** New function gdb.Architecture.integer_type(), which returns an
1057 integer type given a size and a signed-ness.
1059 ** New gdb.TargetConnection object type that represents a connection
1060 (as displayed by the 'info connections' command). A sub-class,
1061 gdb.RemoteTargetConnection, is used to represent 'remote' and
1062 'extended-remote' connections.
1064 ** The gdb.Inferior type now has a 'connection' property which is an
1065 instance of gdb.TargetConnection, the connection used by this
1066 inferior. This can be None if the inferior has no connection.
1068 ** New 'gdb.events.connection_removed' event registry, which emits a
1069 'gdb.ConnectionEvent' when a connection is removed from GDB.
1070 This event has a 'connection' property, a gdb.TargetConnection
1071 object for the connection being removed.
1073 ** New gdb.connections() function that returns a list of all
1074 currently active connections.
1076 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
1077 is equivalent to the existing 'maint packet' CLI command; it
1078 allows a user specified packet to be sent to the remote target.
1080 ** New function gdb.host_charset(), returns a string, which is the
1081 name of the current host charset.
1083 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
1086 ** New gdb.with_parameter(NAME, VALUE). This returns a context
1087 manager that temporarily sets the gdb parameter NAME to VALUE,
1088 then resets it when the context is exited.
1090 ** The gdb.Value.format_string method now takes a 'styling'
1091 argument, which is a boolean. When true, the returned string can
1092 include escape sequences to apply styling. The styling will only
1093 be present if styling is otherwise turned on in GDB (see 'help
1094 set styling'). When false, which is the default if the argument
1095 is not given, then no styling is applied to the returned string.
1097 ** New read-only attribute gdb.InferiorThread.details, which is
1098 either a string, containing additional, target specific thread
1099 state information, or None, if there is no such additional
1102 ** New read-only attribute gdb.Type.is_scalar, which is True for
1103 scalar types, and False for all other types.
1105 ** New read-only attribute gdb.Type.is_signed. This attribute
1106 should only be read when Type.is_scalar is True, and will be True
1107 for signed types, and False for all other types. Attempting to
1108 read this attribute for non-scalar types will raise a ValueError.
1110 ** It is now possible to add GDB/MI commands implemented in Python.
1112 * New features in the GDB remote stub, GDBserver
1114 ** GDBserver is now supported on OpenRISC GNU/Linux.
1116 * New native configurations
1118 GNU/Linux/OpenRISC or1k*-*-linux*
1120 *** Changes in GDB 11
1122 * The 'set disassembler-options' command now supports specifying options
1125 * GDB now supports general memory tagging functionality if the underlying
1126 architecture supports the proper primitives and hooks. Currently this is
1127 enabled only for AArch64 MTE.
1131 - Additional information when the inferior crashes with a SIGSEGV caused by
1132 a memory tag violation.
1134 - A new modifier 'm' for the "x" command, which displays allocation tags for a
1135 particular memory range.
1137 - Display of memory tag mismatches by "print", for addresses and
1138 pointers, if memory tagging is supported by the architecture.
1140 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
1145 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
1147 The MI -break-insert and -dprintf-insert commands now support a
1148 new "--qualified" option that makes GDB interpret a specified
1149 function name as a complete fully-qualified name. This is the
1150 equivalent of the CLI's "break -qualified" and "dprintf
1153 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
1155 The MI -break-insert and -dprintf-insert commands now support a
1156 '--force-condition' flag to forcibly define a condition even when
1157 the condition is invalid at all locations of the breakpoint. This
1158 is equivalent to the '-force-condition' flag of the CLI's "break"
1161 ** '-break-condition --force'
1163 The MI -break-condition command now supports a '--force' flag to
1164 forcibly define a condition even when the condition is invalid at
1165 all locations of the selected breakpoint. This is equivalent to
1166 the '-force' flag of the CLI's "cond" command.
1168 ** '-file-list-exec-source-files [--group-by-objfile]
1169 [--basename | --dirname]
1172 The existing -file-list-exec-source-files command now takes an
1173 optional REGEXP which is used to filter the source files that are
1174 included in the results.
1176 By default REGEXP is matched against the full filename of the
1177 source file. When one of --basename or --dirname is given then
1178 REGEXP is only matched against the specified part of the full
1181 When the optional --group-by-objfile flag is used the output
1182 format is changed, the results are now a list of object files
1183 (executable and libraries) with the source files that are
1184 associated with each object file.
1186 The results from -file-list-exec-source-files now include a
1187 'debug-fully-read' field which takes the value 'true' or 'false'.
1188 A 'true' value indicates the source file is from a compilation
1189 unit that has had its debug information fully read in by GDB, a
1190 value of 'false' indicates GDB has only performed a partial scan
1191 of the debug information so far.
1193 * GDB now supports core file debugging for x86_64 Cygwin programs.
1195 * GDB will now look for the .gdbinit file in a config directory before
1196 looking for ~/.gdbinit. The file is searched for in the following
1197 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
1198 $HOME/.gdbinit. On Apple hosts the search order is instead:
1199 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
1201 * GDB now supports fixed point types which are described in DWARF
1202 as base types with a fixed-point encoding. Additionally, support
1203 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
1206 For Ada, this allows support for fixed point types without requiring
1207 the use of the GNAT encoding (based on information added to the type's
1208 name following a GNAT-specific format).
1210 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
1211 or ~/.gdbearlyinit if these files are present. These files are
1212 processed earlier than any of the other initialization files and
1213 can affect parts of GDB's startup that previously had already been
1214 completed before the initialization files were read, for example
1215 styling of the initial GDB greeting.
1217 * GDB now has two new options "--early-init-command" and
1218 "--early-init-eval-command" with corresponding short options "-eix"
1219 and "-eiex" that allow options (that would normally appear in a
1220 gdbearlyinit file) to be passed on the command line.
1222 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
1223 now understood by GDB, and can be used to describe the vector
1224 registers of a target. The precise requirements of this register
1225 feature are documented in the GDB manual.
1227 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
1228 supported by GDB and describes a new VPR register from the ARM MVE
1229 (Helium) extension. See the GDB manual for more information.
1233 ** TUI windows now support mouse actions. The mouse wheel scrolls
1234 the appropriate window.
1236 ** Key combinations that do not have a specific action on the
1237 focused window are passed to GDB. For example, you now can use
1238 Ctrl-Left/Ctrl-Right to move between words in the command window
1239 regardless of which window is in focus. Previously you would
1240 need to focus on the command window for such key combinations to
1245 set debug event-loop
1246 show debug event-loop
1247 Control the display of debug output about GDB's event loop.
1249 set print memory-tag-violations
1250 show print memory-tag-violations
1251 Control whether to display additional information about memory tag violations
1252 when printing pointers and addresses. Architecture support for memory
1253 tagging is required for this option to have an effect.
1255 maintenance flush symbol-cache
1256 maintenance flush register-cache
1257 These new commands are equivalent to the already existing commands
1258 'maintenance flush-symbol-cache' and 'flushregs' respectively.
1260 maintenance flush dcache
1261 A new command to flush the dcache.
1263 maintenance info target-sections
1264 Print GDB's internal target sections table.
1266 maintenance info jit
1267 Print the JIT code objects in the inferior known to GDB.
1269 memory-tag show-logical-tag POINTER
1270 Print the logical tag for POINTER.
1271 memory-tag with-logical-tag POINTER TAG
1272 Print POINTER with logical tag TAG.
1273 memory-tag show-allocation-tag ADDRESS
1274 Print the allocation tag for ADDRESS.
1275 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1276 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1277 memory-tag check POINTER
1278 Validate that POINTER's logical tag matches the allocation tag.
1280 set startup-quietly on|off
1281 show startup-quietly
1282 When 'on', this causes GDB to act as if "-silent" were passed on the
1283 command line. This command needs to be added to an early
1284 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1287 set print type hex on|off
1289 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1290 and offsets of struct members. When 'off', decimal notation is used.
1292 set python ignore-environment on|off
1293 show python ignore-environment
1294 When 'on', this causes GDB's builtin Python to ignore any
1295 environment variables that would otherwise affect how Python
1296 behaves. This command needs to be added to an early initialization
1297 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1299 set python dont-write-bytecode auto|on|off
1300 show python dont-write-bytecode
1301 When 'on', this causes GDB's builtin Python to not write any
1302 byte-code (.pyc files) to disk. This command needs to be added to
1303 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1304 order to affect GDB. When 'off' byte-code will always be written.
1305 When set to 'auto' (the default) Python will check the
1306 PYTHONDONTWRITEBYTECODE environment variable.
1310 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1311 [-force-condition] [if CONDITION]
1312 This command would previously refuse setting a breakpoint if the
1313 CONDITION expression is invalid at a location. It now accepts and
1314 defines the breakpoint if there is at least one location at which
1315 the CONDITION is valid. The locations for which the CONDITION is
1316 invalid, are automatically disabled. If CONDITION is invalid at all
1317 of the locations, setting the breakpoint is still rejected. However,
1318 the '-force-condition' flag can be used in this case for forcing GDB to
1319 define the breakpoint, making all the current locations automatically
1320 disabled. This may be useful if the user knows the condition will
1321 become meaningful at a future location, e.g. due to a shared library
1324 condition [-force] N COND
1325 The behavior of this command is changed the same way for the 'break'
1326 command as explained above. The '-force' flag can be used to force
1327 GDB into defining the condition even when COND is invalid for all the
1328 current locations of breakpoint N.
1331 maintenance flush-symbol-cache
1332 These commands are deprecated in favor of the new commands
1333 'maintenance flush register-cache' and 'maintenance flush
1334 symbol-cache' respectively.
1336 set style version foreground COLOR
1337 set style version background COLOR
1338 set style version intensity VALUE
1339 Control the styling of GDB's version number text.
1342 When the ID parameter is omitted, then this command prints information
1343 about the current inferior. When the ID parameter is present, the
1344 behavior of the command is unchanged and have the inferior ID become
1345 the current inferior.
1347 maintenance info sections
1348 The ALLOBJ keyword has been replaced with an -all-objects command
1349 line flag. It is now possible to filter which sections are printed
1350 even when -all-objects is passed.
1352 ptype[/FLAGS] TYPE | EXPRESSION
1353 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
1354 notation is used when printing sizes and offsets of struct members.
1355 When '/d' is set, decimal notation is used when printing sizes and
1356 offsets of struct members. Default behavior is given by 'show print
1360 The info sources command output has been restructured. The results
1361 are now based around a list of objfiles (executable and libraries),
1362 and for each objfile the source files that are part of that objfile
1365 * Removed targets and native configurations
1367 ARM Symbian arm*-*-symbianelf*
1369 * New remote packets
1372 Request the remote to send allocation tags for a particular memory range.
1374 Request the remote to store the specified allocation tags to the requested
1379 ** Improved support for rvalue reference values:
1380 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1381 value-referenced-value procedure now handles rvalue reference
1384 ** New procedures for obtaining value variants:
1385 value-reference-value, value-rvalue-reference-value and
1388 ** Temporary breakpoints can now be created with make-breakpoint and
1389 tested for using breakpoint-temporary?.
1393 ** Inferior objects now contain a read-only 'connection_num' attribute that
1394 gives the connection number as seen in 'info connections' and
1397 ** New method gdb.Frame.level() which returns the stack level of the
1400 ** New method gdb.PendingFrame.level() which returns the stack level
1401 of the frame object.
1403 ** When hitting a catchpoint, the Python API will now emit a
1404 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1405 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1407 ** Python TUI windows can now receive mouse click events. If the
1408 Window object implements the click method, it is called for each
1409 mouse click event in this window.
1411 *** Changes in GDB 10
1413 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1414 and "org.gnu.gdb.arc.aux". The old names are still supported but
1415 must be considered obsolete. They will be deprecated after some
1418 * Help and apropos commands will now show the documentation of a
1419 command only once, even if that command has one or more aliases.
1420 These commands now show the command name, then all of its aliases,
1421 and finally the description of the command.
1423 * 'help aliases' now shows only the user defined aliases. GDB predefined
1424 aliases are shown together with their aliased command.
1426 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1427 debugging information as well as source code.
1429 When built with debuginfod, GDB can automatically query debuginfod
1430 servers for the separate debug files and source code of the executable
1433 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1434 requires libdebuginfod, the debuginfod client library).
1436 debuginfod is distributed with elfutils, starting with version 0.178.
1438 You can get the latest version from https://sourceware.org/elfutils.
1440 * Multi-target debugging support
1442 GDB now supports debugging multiple target connections
1443 simultaneously. For example, you can now have each inferior
1444 connected to different remote servers running in different machines,
1445 or have one inferior debugging a local native process, an inferior
1446 debugging a core dump, etc.
1448 This support is experimental and comes with some limitations -- you
1449 can only resume multiple targets simultaneously if all targets
1450 support non-stop mode, and all remote stubs or servers must support
1451 the same set of remote protocol features exactly. See also "info
1452 connections" and "add-inferior -no-connection" below, and "maint set
1453 target-non-stop" in the user manual.
1455 * New features in the GDB remote stub, GDBserver
1457 ** GDBserver is now supported on ARC GNU/Linux.
1459 ** GDBserver is now supported on RISC-V GNU/Linux.
1461 ** GDBserver no longer supports these host triplets:
1463 i[34567]86-*-lynxos*
1472 i[34567]86-*-mingw32ce*
1474 * Debugging MS-Windows processes now sets $_exitsignal when the
1475 inferior is terminated by a signal, instead of setting $_exitcode.
1477 * Multithreaded symbol loading has now been enabled by default on systems
1478 that support it (see entry for GDB 9, below), providing faster
1479 performance for programs with many symbols.
1481 * The $_siginfo convenience variable now also works on Windows targets,
1482 and will display the EXCEPTION_RECORD of the last handled exception.
1484 * TUI windows can now be arranged horizontally.
1486 * The command history filename can now be set to the empty string
1487 either using 'set history filename' or by setting 'GDBHISTFILE=' in
1488 the environment. The effect of setting this filename to the empty
1489 string is that GDB will not try to load any previous command
1492 * On Windows targets, it is now possible to debug 32-bit programs with a
1497 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1498 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1499 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
1500 running process, this new option indicates whether to detect
1501 a mismatch between the current executable file loaded by GDB and the
1502 executable file used to start the process. If 'ask', the default,
1503 display a warning and ask the user whether to load the process
1504 executable file; if 'warn', just display a warning; if 'off', don't
1505 attempt to detect a mismatch.
1507 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1508 Define a new TUI layout, specifying its name and the windows that
1511 maintenance print xml-tdesc [FILE]
1512 Prints the current target description as an XML document. If the
1513 optional FILE is provided (which is an XML target description) then
1514 the target description is read from FILE into GDB, and then
1517 maintenance print core-file-backed-mappings
1518 Prints file-backed mappings loaded from a core file's note section.
1519 Output is expected to be similar to that of "info proc mappings".
1521 set debug fortran-array-slicing on|off
1522 show debug fortran-array-slicing
1523 Print debugging when taking slices of Fortran arrays.
1525 set fortran repack-array-slices on|off
1526 show fortran repack-array-slices
1527 When taking slices from Fortran arrays and strings, if the slice is
1528 non-contiguous within the original value then, when this option is
1529 on, the new value will be repacked into a single contiguous value.
1530 When this option is off, then the value returned will consist of a
1531 descriptor that describes the slice within the memory of the
1532 original parent value.
1536 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1537 The alias command can now specify default args for an alias.
1538 GDB automatically prepends the alias default args to the argument list
1539 provided explicitly by the user.
1540 For example, to have a backtrace with full details, you can define
1541 an alias 'bt_ALL' as
1542 'alias bt_ALL = backtrace -entry-values both -frame-arg all
1543 -past-main -past-entry -full'.
1544 Alias default arguments can also use a set of nested 'with' commands,
1545 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1546 defines the alias pp10 that will pretty print a maximum of 10 elements
1547 of the given expression (if the expression is an array).
1551 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
1552 BPF bpf-unknown-none
1557 ** gdb.register_window_type can be used to implement new TUI windows
1560 ** Dynamic types can now be queried. gdb.Type has a new attribute,
1561 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
1562 field of a dynamic type may have None for its "bitpos" attribute
1565 ** Commands written in Python can be in the "TUI" help class by
1566 registering with the new constant gdb.COMMAND_TUI.
1568 ** New method gdb.PendingFrame.architecture () to retrieve the
1569 architecture of the pending frame.
1571 ** New gdb.Architecture.registers method that returns a
1572 gdb.RegisterDescriptorIterator object, an iterator that returns
1573 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
1574 way to query the registers available for an architecture.
1576 ** New gdb.Architecture.register_groups method that returns a
1577 gdb.RegisterGroupIterator object, an iterator that returns
1578 gdb.RegisterGroup objects. The new RegisterGroup is a way to
1579 discover the available register groups.
1583 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1585 ** Procedures 'memory-port-read-buffer-size',
1586 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1587 and 'set-memory-port-write-buffer-size!' are deprecated. When
1588 using Guile 2.2 and later, users who need to control the size of
1589 a memory port's internal buffer can use the 'setvbuf' procedure.
1591 *** Changes in GDB 9
1593 * 'thread-exited' event is now available in the annotations interface.
1595 * New built-in convenience variables $_gdb_major and $_gdb_minor
1596 provide the GDB version. They are handy for conditionally using
1597 features available only in or since specific GDB versions, in
1598 scripts that should work error-free with many different versions,
1599 such as in system-wide init files.
1601 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1602 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1603 of the GDB settings and the GDB maintenance settings. They are handy
1604 for changing the logic of user defined commands depending on the
1605 current GDB settings.
1607 * GDB now supports Thread Local Storage (TLS) variables on several
1608 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1609 architectures require kernel changes. TLS is not yet supported for
1610 amd64 and i386 process core dumps.
1612 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1613 addresses that required unmasking are shown in the backtrace with the
1616 * Two new convenience functions $_cimag and $_creal that extract the
1617 imaginary and real parts respectively from complex numbers.
1619 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1620 provide the exitcode or exit status of the shell commands launched by
1621 GDB commands such as "shell", "pipe" and "make".
1623 * The command define-prefix can now define user defined prefix commands.
1624 User defined commands can now be defined using these user defined prefix
1627 * Command names can now use the . character.
1629 * The RX port now supports XML target descriptions.
1631 * GDB now shows the Ada task names at more places, e.g. in task switching
1634 * GDB can now be compiled with Python 3 on Windows.
1636 * New convenience variable $_ada_exception holds the address of the
1637 Ada exception being thrown. This is set by Ada-related catchpoints.
1639 * GDB can now place breakpoints on nested functions and subroutines in
1640 Fortran code. The '::' operator can be used between parent and
1641 child scopes when placing breakpoints, for example:
1643 (gdb) break outer_function::inner_function
1645 The 'outer_function::' prefix is only needed if 'inner_function' is
1646 not visible in the current scope.
1648 * In addition to the system-wide gdbinit file, if configured with
1649 --with-system-gdbinit-dir, GDB will now also load files in that directory
1650 as system gdbinit files, unless the -nx or -n flag is provided. Files
1651 with extensions .gdb, .py and .scm are supported as long as GDB was
1652 compiled with support for that language.
1654 * GDB now supports multithreaded symbol loading for higher performance.
1655 This feature is still in testing, so it is disabled by default. You
1656 can turn it on using 'maint set worker-threads unlimited'.
1660 ** The gdb.Value type has a new method 'format_string' which returns a
1661 string representing the value. The formatting is controlled by the
1662 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1663 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1664 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1666 ** gdb.Type has a new property 'objfile' which returns the objfile the
1667 type was defined in.
1669 ** The frame information printed by the python frame filtering code
1670 is now consistent with what the 'backtrace' command prints when
1671 there are no filters, or when the 'backtrace' '-no-filters' option
1674 ** The new function gdb.lookup_static_symbol can be used to look up
1675 symbols with static linkage.
1677 ** The new function gdb.lookup_static_symbols can be used to look up
1678 all static symbols with static linkage.
1680 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1681 'lookup_static_symbol' to lookup a symbol from this objfile only.
1683 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1684 this block (e.g. block['local_variable']).
1688 | [COMMAND] | SHELL_COMMAND
1689 | -d DELIM COMMAND DELIM SHELL_COMMAND
1690 pipe [COMMAND] | SHELL_COMMAND
1691 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1692 Executes COMMAND and sends its output to SHELL_COMMAND.
1693 With no COMMAND, repeat the last executed command
1694 and send its output to SHELL_COMMAND.
1696 define-prefix COMMAND
1697 Define or mark a command as a user-defined prefix command.
1699 with SETTING [VALUE] [-- COMMAND]
1700 w SETTING [VALUE] [-- COMMAND]
1701 Temporarily set SETTING, run COMMAND, and restore SETTING.
1702 Usage: with SETTING -- COMMAND
1703 With no COMMAND, repeats the last executed command.
1704 SETTING is any GDB setting you can change with the "set"
1705 subcommands. For example, 'with language c -- print someobj'
1706 temporarily switches to the C language in order to print someobj.
1707 Settings can be combined: 'w lang c -- w print elements unlimited --
1708 usercmd' switches to the C language and runs usercmd with no limit
1709 of array elements to print.
1711 maint with SETTING [VALUE] [-- COMMAND]
1712 Like "with", but works with "maintenance set" settings.
1714 set may-call-functions [on|off]
1715 show may-call-functions
1716 This controls whether GDB will attempt to call functions in
1717 the program, such as with expressions in the print command. It
1718 defaults to on. Calling functions in the program being debugged
1719 can have undesired side effects. It is now possible to forbid
1720 such function calls. If function calls are forbidden, GDB will throw
1721 an error when a command (such as print expression) calls a function
1724 set print finish [on|off]
1726 This controls whether the `finish' command will display the value
1727 that is returned by the current function. When `off', the value is
1728 still entered into the value history, but it is not printed. The
1732 show print max-depth
1733 Allows deeply nested structures to be simplified when printing by
1734 replacing deeply nested parts (beyond the max-depth) with ellipses.
1735 The default max-depth is 20, but this can be set to unlimited to get
1736 the old behavior back.
1738 set print raw-values [on|off]
1739 show print raw-values
1740 By default, GDB applies the enabled pretty printers when printing a
1741 value. This allows to ignore the enabled pretty printers for a series
1742 of commands. The default is 'off'.
1744 set logging debugredirect [on|off]
1745 By default, GDB debug output will go to both the terminal and the logfile.
1746 Set if you want debug output to go only to the log file.
1748 set style title foreground COLOR
1749 set style title background COLOR
1750 set style title intensity VALUE
1751 Control the styling of titles.
1753 set style highlight foreground COLOR
1754 set style highlight background COLOR
1755 set style highlight intensity VALUE
1756 Control the styling of highlightings.
1758 maint set worker-threads
1759 maint show worker-threads
1760 Control the number of worker threads that can be used by GDB. The
1761 default is 0. "unlimited" lets GDB choose a number that is
1762 reasonable. Currently worker threads are only used when demangling
1763 the names of linker symbols.
1765 set style tui-border foreground COLOR
1766 set style tui-border background COLOR
1767 Control the styling of TUI borders.
1769 set style tui-active-border foreground COLOR
1770 set style tui-active-border background COLOR
1771 Control the styling of the active TUI border.
1773 maint set test-settings KIND
1774 maint show test-settings KIND
1775 A set of commands used by the testsuite for exercising the settings
1778 maint set tui-resize-message [on|off]
1779 maint show tui-resize-message
1780 Control whether GDB prints a message each time the terminal is
1781 resized when in TUI mode. This is primarily useful for testing the
1784 set print frame-info [short-location|location|location-and-address
1785 |source-and-location|source-line|auto]
1786 show print frame-info
1787 This controls what frame information is printed by the commands printing
1788 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1789 'frame', 'stepi'. The python frame filtering also respect this setting.
1790 The 'backtrace' '-frame-info' option can override this global setting.
1792 set tui compact-source
1793 show tui compact-source
1795 Enable the "compact" display mode for the TUI source window. The
1796 compact display uses only as much space as is needed for the line
1797 numbers in the current file, and only a single space to separate the
1798 line numbers from the source.
1800 info modules [-q] [REGEXP]
1801 Return a list of Fortran modules matching REGEXP, or all modules if
1804 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1805 Return a list of functions within all modules, grouped by module.
1806 The list of functions can be restricted with the optional regular
1807 expressions. MODULE_REGEXP matches against the module name,
1808 TYPE_REGEXP matches against the function type signature, and REGEXP
1809 matches against the function name.
1811 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1812 Return a list of variables within all modules, grouped by module.
1813 The list of variables can be restricted with the optional regular
1814 expressions. MODULE_REGEXP matches against the module name,
1815 TYPE_REGEXP matches against the variable type, and REGEXP matches
1816 against the variable name.
1818 set debug remote-packet-max-chars
1819 show debug remote-packet-max-chars
1820 Controls the number of characters to output in a remote packet when using
1822 The default is 512 bytes.
1825 Lists the target connections currently in use.
1830 The "help" command uses the title style to enhance the
1831 readibility of its output by styling the classes and
1835 Similarly to "help", the "apropos" command also uses the
1836 title style for the command names. "apropos" accepts now
1837 a flag "-v" (verbose) to show the full documentation
1838 of matching commands and to use the highlight style to mark
1839 the documentation parts matching REGEXP.
1843 The GDB printf and eval commands can now print C-style and Ada-style
1844 string convenience variables without calling functions in the program.
1845 This allows to do formatted printing of strings without having
1846 a running inferior, or when debugging a core dump.
1848 info sources [-dirname | -basename] [--] [REGEXP]
1849 This command has now optional arguments to only print the files
1850 whose names match REGEXP. The arguments -dirname and -basename
1851 allow to restrict matching respectively to the dirname and basename
1855 The "show style" and its subcommands are now styling
1856 a style name in their output using its own style, to help
1857 the user visualize the different styles.
1859 set print frame-arguments
1860 The new value 'presence' indicates to only indicate the presence of
1861 arguments using ..., instead of printing argument names and values.
1863 set print raw-frame-arguments
1864 show print raw-frame-arguments
1866 These commands replace the similarly-named "set/show print raw
1867 frame-arguments" commands (now with a dash instead of a space). The
1868 old commands are now deprecated and may be removed in a future
1871 add-inferior [-no-connection]
1872 The add-inferior command now supports a "-no-connection" flag that
1873 makes the new inferior start with no target connection associated.
1874 By default, the new inferior inherits the target connection of the
1875 current inferior. See also "info connections".
1878 This command's output now includes a new "Connection" column
1879 indicating which target connection an inferior is bound to. See
1880 "info connections" above.
1882 maint test-options require-delimiter
1883 maint test-options unknown-is-error
1884 maint test-options unknown-is-operand
1885 maint show test-options-completion-result
1886 Commands used by the testsuite to validate the command options
1889 focus, winheight, +, -, >, <
1890 These commands are now case-sensitive.
1892 * New command options, command completion
1894 GDB now has a standard infrastructure to support dash-style command
1895 options ('-OPT'). One benefit is that commands that use it can
1896 easily support completion of command line arguments. Try "CMD
1897 -[TAB]" or "help CMD" to find options supported by a command. Over
1898 time, we intend to migrate most commands to this infrastructure. A
1899 number of commands got support for new command options in this
1902 ** The "print" and "compile print" commands now support a number of
1903 options that allow overriding relevant global print settings as
1904 set by "set print" subcommands:
1908 -array-indexes [on|off]
1909 -elements NUMBER|unlimited
1913 -raw-values [on|off]
1914 -repeats NUMBER|unlimited
1915 -static-members [on|off]
1920 Note that because the "print"/"compile print" commands accept
1921 arbitrary expressions which may look like options (including
1922 abbreviations), if you specify any command option, then you must
1923 use a double dash ("--") to mark the end of argument processing.
1925 ** The "backtrace" command now supports a number of options that
1926 allow overriding relevant global print settings as set by "set
1927 backtrace" and "set print" subcommands:
1929 -entry-values no|only|preferred|if-needed|both|compact|default
1930 -frame-arguments all|scalars|none
1931 -raw-frame-arguments [on|off]
1932 -frame-info auto|source-line|location|source-and-location
1933 |location-and-address|short-location
1935 -past-entry [on|off]
1937 In addition, the full/no-filters/hide qualifiers are now also
1938 exposed as command options too:
1944 ** The "frame apply", "tfaas" and "faas" commands similarly now
1945 support the following options:
1948 -past-entry [on|off]
1950 ** The new "info sources" options -dirname and -basename options
1951 are using the standard '-OPT' infrastructure.
1953 All options above can also be abbreviated. The argument of boolean
1954 (on/off) options can be 0/1 too, and also the argument is assumed
1955 "on" if omitted. This allows writing compact command invocations,
1958 (gdb) p -ra -p -o 0 -- *myptr
1960 The above is equivalent to:
1962 (gdb) print -raw-values -pretty -object off -- *myptr
1964 ** The "info types" command now supports the '-q' flag to disable
1965 printing of some header information in a similar fashion to "info
1966 variables" and "info functions".
1968 ** The "info variables", "info functions", and "whereis" commands
1969 now take a '-n' flag that excludes non-debug symbols (symbols
1970 from the symbol table, not from the debug info such as DWARF)
1973 * Completion improvements
1975 ** GDB can now complete the options of the "thread apply all" and
1976 "taas" commands, and their "-ascending" option can now be
1979 ** GDB can now complete the options of the "info threads", "info
1980 functions", "info variables", "info locals", and "info args"
1983 ** GDB can now complete the options of the "compile file" and
1984 "compile code" commands. The "compile file" command now
1985 completes on filenames.
1987 ** GDB can now complete the backtrace command's
1988 "full/no-filters/hide" qualifiers.
1990 * In settings, you can now abbreviate "unlimited".
1992 E.g., "set print elements u" is now equivalent to "set print
1993 elements unlimited".
1998 This lists all the possible completions for the rest of the line, if it
1999 were to be given as a command itself. This is intended for use by MI
2000 frontends in cases when separate CLI and MI channels cannot be used.
2002 -catch-throw, -catch-rethrow, and -catch-catch
2003 These can be used to catch C++ exceptions in a similar fashion to
2004 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
2006 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
2007 These commands are the MI equivalent of the CLI commands 'info
2008 functions', 'info types', and 'info variables' respectively.
2010 -symbol-info-modules, this is the MI equivalent of the CLI 'info
2013 -symbol-info-module-functions and -symbol-info-module-variables.
2014 These commands are the MI equivalent of the CLI commands 'info
2015 module functions' and 'info module variables'.
2019 ** The default version of the MI interpreter is now 3 (-i=mi3).
2021 ** The output of information about multi-location breakpoints (which is
2022 syntactically incorrect in MI 2) has changed in MI 3. This affects
2023 the following commands and events:
2027 - =breakpoint-created
2028 - =breakpoint-modified
2030 The -fix-multi-location-breakpoint-output command can be used to enable
2031 this behavior with previous MI versions.
2033 ** Backtraces and frames include a new optional field addr_flags which is
2034 given after the addr field. On AArch64 this contains PAC if the address
2035 has been masked in the frame. On all other targets the field is not
2040 The testsuite now creates the files gdb.cmd (containing the arguments
2041 used to launch GDB) and gdb.in (containing all the commands sent to
2042 GDB) in the output directory for each test script. Multiple invocations
2043 are appended with .1, .2, .3 etc.
2045 * Building GDB and GDBserver now requires GNU make >= 3.82.
2047 Using another implementation of the make program or an earlier version of
2048 GNU make to build GDB or GDBserver is not supported.
2050 * Building GDB now requires GNU readline >= 7.0.
2052 GDB now bundles GNU readline 8.0, but if you choose to use
2053 --with-system-readline, only readline >= 7.0 can be used.
2055 * The TUI SingleKey keymap is now named "SingleKey". This can be used
2056 from .inputrc to bind keys in this keymap. This feature is only
2057 available when gdb is built against GNU readline 8.0 or later.
2059 * Removed targets and native configurations
2061 GDB no longer supports debugging the Cell Broadband Engine. This includes
2062 both debugging standalone Cell/B.E. SPU applications and integrated debugging
2063 of Cell/B.E. applications that use both the PPU and SPU architectures.
2069 * Removed targets and native configurations
2071 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
2072 sparc*-*-solaris2.10
2074 *** Changes in GDB 8.3
2076 * GDB and GDBserver now support access to additional registers on
2077 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
2080 * GDB now has experimental support for the compilation and injection of
2081 C++ source code into the inferior. This beta release does not include
2082 support for several language features, such as templates, constructors,
2085 This feature requires GCC 7.1 or higher built with libcp1.so
2088 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
2089 can be passed using the '[ADDRESS]:PORT' notation, or the regular
2090 'ADDRESS:PORT' method.
2092 * DWARF index cache: GDB can now automatically save indices of DWARF
2093 symbols on disk to speed up further loading of the same binaries.
2095 * Ada task switching is now supported on aarch64-elf targets when
2096 debugging a program using the Ravenscar Profile. For more information,
2097 see the "Tasking Support when using the Ravenscar Profile" section
2098 in the GDB user manual.
2100 * GDB in batch mode now exits with status 1 if the last command to be
2103 * The RISC-V target now supports target descriptions.
2105 * System call catchpoints now support system call aliases on FreeBSD.
2106 When the ABI of a system call changes in FreeBSD, this is
2107 implemented by leaving a compatibility system call using the old ABI
2108 at the existing number and allocating a new system call number for
2109 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
2110 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
2111 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
2112 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
2113 so that a system call catchpoint for the 'kevent' system call will
2114 catch invocations of both the 'kevent' and 'freebsd11_kevent'
2115 binaries. This ensures that 'kevent' system calls are caught for
2116 binaries using either the old or new ABIs.
2118 * Terminal styling is now available for the CLI and the TUI. GNU
2119 Source Highlight can additionally be used to provide styling of
2120 source code snippets. See the "set style" commands, below, for more
2123 * Removed support for old demangling styles arm, edg, gnu, hp and
2128 set debug compile-cplus-types
2129 show debug compile-cplus-types
2130 Control the display of debug output about type conversion in the
2131 C++ compile feature. Commands have no effect while compiling
2132 for other languages.
2136 Control whether debug output about files/functions skipping is
2139 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
2140 Apply a command to some frames.
2141 FLAG arguments allow to control what output to produce and how to handle
2142 errors raised when applying COMMAND to a frame.
2145 Apply a command to all threads (ignoring errors and empty output).
2146 Shortcut for 'thread apply all -s COMMAND'.
2149 Apply a command to all frames (ignoring errors and empty output).
2150 Shortcut for 'frame apply all -s COMMAND'.
2153 Apply a command to all frames of all threads (ignoring errors and empty
2155 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
2157 maint set dwarf unwinders (on|off)
2158 maint show dwarf unwinders
2159 Control whether DWARF unwinders can be used.
2162 Display a list of open files for a process.
2166 Changes to the "frame", "select-frame", and "info frame" CLI commands.
2167 These commands all now take a frame specification which
2168 is either a frame level, or one of the keywords 'level', 'address',
2169 'function', or 'view' followed by a parameter. Selecting a frame by
2170 address, or viewing a frame outside the current backtrace now
2171 requires the use of a keyword. Selecting a frame by level is
2172 unchanged. The MI comment "-stack-select-frame" is unchanged.
2174 target remote FILENAME
2175 target extended-remote FILENAME
2176 If FILENAME is a Unix domain socket, GDB will attempt to connect
2177 to this socket instead of opening FILENAME as a character device.
2179 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2180 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2181 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2182 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2183 These commands can now print only the searched entities
2184 matching the provided regexp(s), giving a condition
2185 on the entity names or entity types. The flag -q disables
2186 printing headers or informations messages.
2192 These commands now determine the syntax for the shown entities
2193 according to the language chosen by `set language'. In particular,
2194 `set language auto' means to automatically choose the language of
2197 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
2198 The 'thread apply' command accepts new FLAG arguments.
2199 FLAG arguments allow to control what output to produce and how to handle
2200 errors raised when applying COMMAND to a thread.
2202 set tui tab-width NCHARS
2203 show tui tab-width NCHARS
2204 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
2206 set style enabled [on|off]
2208 Enable or disable terminal styling. Styling is enabled by default
2209 on most hosts, but disabled by default when in batch mode.
2211 set style sources [on|off]
2213 Enable or disable source code styling. Source code styling is
2214 enabled by default, but only takes effect if styling in general is
2215 enabled, and if GDB was linked with GNU Source Highlight.
2217 set style filename foreground COLOR
2218 set style filename background COLOR
2219 set style filename intensity VALUE
2220 Control the styling of file names.
2222 set style function foreground COLOR
2223 set style function background COLOR
2224 set style function intensity VALUE
2225 Control the styling of function names.
2227 set style variable foreground COLOR
2228 set style variable background COLOR
2229 set style variable intensity VALUE
2230 Control the styling of variable names.
2232 set style address foreground COLOR
2233 set style address background COLOR
2234 set style address intensity VALUE
2235 Control the styling of addresses.
2239 ** The '-data-disassemble' MI command now accepts an '-a' option to
2240 disassemble the whole function surrounding the given program
2241 counter value or function name. Support for this feature can be
2242 verified by using the "-list-features" command, which should
2243 contain "data-disassemble-a-option".
2245 ** Command responses and notifications that include a frame now include
2246 the frame's architecture in a new "arch" attribute.
2248 * New native configurations
2250 GNU/Linux/RISC-V riscv*-*-linux*
2251 FreeBSD/riscv riscv*-*-freebsd*
2255 GNU/Linux/RISC-V riscv*-*-linux*
2256 CSKY ELF csky*-*-elf
2257 CSKY GNU/LINUX csky*-*-linux
2258 FreeBSD/riscv riscv*-*-freebsd*
2260 GNU/Linux/OpenRISC or1k*-*-linux*
2264 GDB no longer supports native debugging on versions of MS-Windows
2269 ** GDB no longer supports Python versions less than 2.6.
2271 ** The gdb.Inferior type has a new 'progspace' property, which is the program
2272 space associated to that inferior.
2274 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2275 of objfiles associated to that program space.
2277 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2278 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2281 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2282 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
2283 correct and did not work properly.
2285 ** The gdb.Value type has a new constructor, which is used to construct a
2286 gdb.Value from a Python buffer object and a gdb.Type.
2292 Enable or disable the undefined behavior sanitizer. This is
2293 disabled by default, but passing --enable-ubsan=yes or
2294 --enable-ubsan=auto to configure will enable it. Enabling this can
2295 cause a performance penalty. The undefined behavior sanitizer was
2296 first introduced in GCC 4.9.
2298 *** Changes in GDB 8.2
2300 * The 'set disassembler-options' command now supports specifying options
2301 for the MIPS target.
2303 * The 'symbol-file' command now accepts an '-o' option to add a relative
2304 offset to all sections.
2306 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2307 a relative offset to all sections, but it allows to override the load
2308 address of individual sections using '-s'.
2310 * The 'add-symbol-file' command no longer requires the second argument
2311 (address of the text section).
2313 * The endianness used with the 'set endian auto' mode in the absence of
2314 an executable selected for debugging is now the last endianness chosen
2315 either by one of the 'set endian big' and 'set endian little' commands
2316 or by inferring from the last executable used, rather than the startup
2319 * The pager now allows a "c" response, meaning to disable the pager
2320 for the rest of the current command.
2322 * The commands 'info variables/functions/types' now show the source line
2323 numbers of symbol definitions when available.
2325 * 'info proc' now works on running processes on FreeBSD systems and core
2326 files created on FreeBSD systems.
2328 * C expressions can now use _Alignof, and C++ expressions can now use
2331 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
2332 the vector length while the process is running.
2338 Control display of debugging info regarding the FreeBSD native target.
2340 set|show varsize-limit
2341 This new setting allows the user to control the maximum size of Ada
2342 objects being printed when those objects have a variable type,
2343 instead of that maximum size being hardcoded to 65536 bytes.
2345 set|show record btrace cpu
2346 Controls the processor to be used for enabling errata workarounds for
2347 branch trace decode.
2349 maint check libthread-db
2350 Run integrity checks on the current inferior's thread debugging
2353 maint set check-libthread-db (on|off)
2354 maint show check-libthread-db
2355 Control whether to run integrity checks on inferior specific thread
2356 debugging libraries as they are loaded. The default is not to
2357 perform such checks.
2361 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2363 ** The commands attached to a breakpoint can be set by assigning to
2364 the breakpoint's "commands" field.
2366 ** gdb.execute can now execute multi-line gdb commands.
2368 ** The new functions gdb.convenience_variable and
2369 gdb.set_convenience_variable can be used to get and set the value
2370 of convenience variables.
2372 ** A gdb.Parameter will no longer print the "set" help text on an
2373 ordinary "set"; instead by default a "set" will be silent unless
2374 the get_set_string method returns a non-empty string.
2378 RiscV ELF riscv*-*-elf
2380 * Removed targets and native configurations
2382 m88k running OpenBSD m88*-*-openbsd*
2383 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2384 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2385 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2387 * Aarch64/Linux hardware watchpoints improvements
2389 Hardware watchpoints on unaligned addresses are now properly
2390 supported when running Linux kernel 4.10 or higher: read and access
2391 watchpoints are no longer spuriously missed, and all watchpoints
2392 lengths between 1 and 8 bytes are supported. On older kernels,
2393 watchpoints set on unaligned addresses are no longer missed, with
2394 the tradeoff that there is a possibility of false hits being
2399 --enable-codesign=CERT
2400 This can be used to invoke "codesign -s CERT" after building gdb.
2401 This option is useful on macOS, where code signing is required for
2402 gdb to work properly.
2404 --disable-gdbcli has been removed
2405 This is now silently accepted, but does nothing.
2407 *** Changes in GDB 8.1
2409 * GDB now supports dynamically creating arbitrary register groups specified
2410 in XML target descriptions. This allows for finer grain grouping of
2411 registers on systems with a large amount of registers.
2413 * The 'ptype' command now accepts a '/o' flag, which prints the
2414 offsets and sizes of fields in a struct, like the pahole(1) tool.
2416 * New "--readnever" command line option instructs GDB to not read each
2417 symbol file's symbolic debug information. This makes startup faster
2418 but at the expense of not being able to perform symbolic debugging.
2419 This option is intended for use cases where symbolic debugging will
2420 not be used, e.g., when you only need to dump the debuggee's core.
2422 * GDB now uses the GNU MPFR library, if available, to emulate target
2423 floating-point arithmetic during expression evaluation when the target
2424 uses different floating-point formats than the host. At least version
2425 3.1 of GNU MPFR is required.
2427 * GDB now supports access to the guarded-storage-control registers and the
2428 software-based guarded-storage broadcast control registers on IBM z14.
2430 * On Unix systems, GDB now supports transmitting environment variables
2431 that are to be set or unset to GDBserver. These variables will
2432 affect the environment to be passed to the remote inferior.
2434 To inform GDB of environment variables that are to be transmitted to
2435 GDBserver, use the "set environment" command. Only user set
2436 environment variables are sent to GDBserver.
2438 To inform GDB of environment variables that are to be unset before
2439 the remote inferior is started by the GDBserver, use the "unset
2440 environment" command.
2442 * Completion improvements
2444 ** GDB can now complete function parameters in linespecs and
2445 explicit locations without quoting. When setting breakpoints,
2446 quoting around functions names to help with TAB-completion is
2447 generally no longer necessary. For example, this now completes
2450 (gdb) b function(in[TAB]
2451 (gdb) b function(int)
2453 Related, GDB is no longer confused with completing functions in
2454 C++ anonymous namespaces:
2457 (gdb) b (anonymous namespace)::[TAB][TAB]
2458 (anonymous namespace)::a_function()
2459 (anonymous namespace)::b_function()
2461 ** GDB now has much improved linespec and explicit locations TAB
2462 completion support, that better understands what you're
2463 completing and offers better suggestions. For example, GDB no
2464 longer offers data symbols as possible completions when you're
2465 setting a breakpoint.
2467 ** GDB now TAB-completes label symbol names.
2469 ** The "complete" command now mimics TAB completion accurately.
2471 * New command line options (gcore)
2474 Dump all memory mappings.
2476 * Breakpoints on C++ functions are now set on all scopes by default
2478 By default, breakpoints on functions/methods are now interpreted as
2479 specifying all functions with the given name ignoring missing
2480 leading scopes (namespaces and classes).
2482 For example, assuming a C++ program with symbols named:
2487 both commands "break func()" and "break B::func()" set a breakpoint
2490 You can use the new flag "-qualified" to override this. This makes
2491 GDB interpret the specified function name as a complete
2492 fully-qualified name instead. For example, using the same C++
2493 program, the "break -q B::func" command sets a breakpoint on
2494 "B::func", only. A parameter has been added to the Python
2495 gdb.Breakpoint constructor to achieve the same result when creating
2496 a breakpoint from Python.
2498 * Breakpoints on functions marked with C++ ABI tags
2500 GDB can now set breakpoints on functions marked with C++ ABI tags
2501 (e.g., [abi:cxx11]). See here for a description of ABI tags:
2502 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2504 Functions with a C++11 abi tag are demangled/displayed like this:
2506 function[abi:cxx11](int)
2509 You can now set a breakpoint on such functions simply as if they had
2512 (gdb) b function(int)
2514 Or if you need to disambiguate between tags, like:
2516 (gdb) b function[abi:other_tag](int)
2518 Tab completion was adjusted accordingly as well.
2522 ** New events gdb.new_inferior, gdb.inferior_deleted, and
2523 gdb.new_thread are emitted. See the manual for further
2524 description of these.
2526 ** A new function, "gdb.rbreak" has been added to the Python API.
2527 This function allows the setting of a large number of breakpoints
2528 via a regex pattern in Python. See the manual for further details.
2530 ** Python breakpoints can now accept explicit locations. See the
2531 manual for a further description of this feature.
2534 * New features in the GDB remote stub, GDBserver
2536 ** GDBserver is now able to start inferior processes with a
2537 specified initial working directory.
2539 The user can set the desired working directory to be used from
2540 GDB using the new "set cwd" command.
2542 ** New "--selftest" command line option runs some GDBserver self
2543 tests. These self tests are disabled in releases.
2545 ** On Unix systems, GDBserver now does globbing expansion and variable
2546 substitution in inferior command line arguments.
2548 This is done by starting inferiors using a shell, like GDB does.
2549 See "set startup-with-shell" in the user manual for how to disable
2550 this from GDB when using "target extended-remote". When using
2551 "target remote", you can disable the startup with shell by using the
2552 new "--no-startup-with-shell" GDBserver command line option.
2554 ** On Unix systems, GDBserver now supports receiving environment
2555 variables that are to be set or unset from GDB. These variables
2556 will affect the environment to be passed to the inferior.
2558 * When catching an Ada exception raised with a message, GDB now prints
2559 the message in the catchpoint hit notification. In GDB/MI mode, that
2560 information is provided as an extra field named "exception-message"
2561 in the *stopped notification.
2563 * Trait objects can now be inspected When debugging Rust code. This
2564 requires compiler support which will appear in Rust 1.24.
2566 * New remote packets
2568 QEnvironmentHexEncoded
2569 Inform GDBserver of an environment variable that is to be passed to
2570 the inferior when starting it.
2573 Inform GDBserver of an environment variable that is to be unset
2574 before starting the remote inferior.
2577 Inform GDBserver that the environment should be reset (i.e.,
2578 user-set environment variables should be unset).
2581 Indicates whether the inferior must be started with a shell or not.
2584 Tell GDBserver that the inferior to be started should use a specific
2587 * The "maintenance print c-tdesc" command now takes an optional
2588 argument which is the file name of XML target description.
2590 * The "maintenance selftest" command now takes an optional argument to
2591 filter the tests to be run.
2593 * The "enable", and "disable" commands now accept a range of
2594 breakpoint locations, e.g. "enable 1.3-5".
2599 Set and show the current working directory for the inferior.
2601 set|show compile-gcc
2602 Set and show compilation command used for compiling and injecting code
2603 with the 'compile' commands.
2605 set debug separate-debug-file
2606 show debug separate-debug-file
2607 Control the display of debug output about separate debug file search.
2609 set dump-excluded-mappings
2610 show dump-excluded-mappings
2611 Control whether mappings marked with the VM_DONTDUMP flag should be
2612 dumped when generating a core file.
2614 maint info selftests
2615 List the registered selftests.
2618 Start the debugged program stopping at the first instruction.
2621 Control display of debugging messages related to OpenRISC targets.
2623 set|show print type nested-type-limit
2624 Set and show the limit of nesting level for nested types that the
2625 type printer will show.
2627 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2630 * Safer/improved support for debugging with no debug info
2632 GDB no longer assumes functions with no debug information return
2635 This means that GDB now refuses to call such functions unless you
2636 tell it the function's type, by either casting the call to the
2637 declared return type, or by casting the function to a function
2638 pointer of the right type, and calling that:
2640 (gdb) p getenv ("PATH")
2641 'getenv' has unknown return type; cast the call to its declared return type
2642 (gdb) p (char *) getenv ("PATH")
2643 $1 = 0x7fffffffe "/usr/local/bin:/"...
2644 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2645 $2 = 0x7fffffffe "/usr/local/bin:/"...
2647 Similarly, GDB no longer assumes that global variables with no debug
2648 info have type 'int', and refuses to print the variable's value
2649 unless you tell it the variable's type:
2652 'var' has unknown type; cast it to its declared type
2656 * New native configurations
2658 FreeBSD/aarch64 aarch64*-*-freebsd*
2659 FreeBSD/arm arm*-*-freebsd*
2663 FreeBSD/aarch64 aarch64*-*-freebsd*
2664 FreeBSD/arm arm*-*-freebsd*
2665 OpenRISC ELF or1k*-*-elf
2667 * Removed targets and native configurations
2669 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2671 *** Changes in GDB 8.0
2673 * GDB now supports access to the PKU register on GNU/Linux. The register is
2674 added by the Memory Protection Keys for Userspace feature which will be
2675 available in future Intel CPUs.
2677 * GDB now supports C++11 rvalue references.
2681 ** New functions to start, stop and access a running btrace recording.
2682 ** Rvalue references are now supported in gdb.Type.
2684 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2687 * Building GDB and GDBserver now requires a C++11 compiler.
2689 For example, GCC 4.8 or later.
2691 It is no longer possible to build GDB or GDBserver with a C
2692 compiler. The --disable-build-with-cxx configure option has been
2695 * Building GDB and GDBserver now requires GNU make >= 3.81.
2697 It is no longer supported to build GDB or GDBserver with another
2698 implementation of the make program or an earlier version of GNU make.
2700 * Native debugging on MS-Windows supports command-line redirection
2702 Command-line arguments used for starting programs on MS-Windows can
2703 now include redirection symbols supported by native Windows shells,
2704 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2705 as "run", "start", and "set args", as well as the corresponding MI
2708 * Support for thread names on MS-Windows.
2710 GDB now catches and handles the special exception that programs
2711 running on MS-Windows use to assign names to threads in the
2714 * Support for Java programs compiled with gcj has been removed.
2716 * User commands now accept an unlimited number of arguments.
2717 Previously, only up to 10 was accepted.
2719 * The "eval" command now expands user-defined command arguments.
2721 This makes it easier to process a variable number of arguments:
2726 eval "print $arg%d", $i
2731 * Target descriptions can now describe registers for sparc32 and sparc64.
2733 * GDB now supports DWARF version 5 (debug information format).
2734 Its .debug_names index is not yet supported.
2736 * New native configurations
2738 FreeBSD/mips mips*-*-freebsd
2742 Synopsys ARC arc*-*-elf32
2743 FreeBSD/mips mips*-*-freebsd
2745 * Removed targets and native configurations
2747 Alpha running FreeBSD alpha*-*-freebsd*
2748 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2753 Erases all the flash memory regions reported by the target.
2755 maint print arc arc-instruction address
2756 Print internal disassembler information about instruction at a given address.
2760 set disassembler-options
2761 show disassembler-options
2762 Controls the passing of target specific information to the disassembler.
2763 If it is necessary to specify more than one disassembler option then
2764 multiple options can be placed together into a comma separated list.
2765 The default value is the empty string. Currently, the only supported
2766 targets are ARM, PowerPC and S/390.
2771 Erases all the flash memory regions reported by the target. This is
2772 equivalent to the CLI command flash-erase.
2774 -file-list-shared-libraries
2775 List the shared libraries in the program. This is
2776 equivalent to the CLI command "info shared".
2779 Catchpoints stopping the program when Ada exceptions are
2780 handled. This is equivalent to the CLI command "catch handlers".
2782 *** Changes in GDB 7.12
2784 * GDB and GDBserver now build with a C++ compiler by default.
2786 The --enable-build-with-cxx configure option is now enabled by
2787 default. One must now explicitly configure with
2788 --disable-build-with-cxx in order to build with a C compiler. This
2789 option will be removed in a future release.
2791 * GDBserver now supports recording btrace without maintaining an active
2794 * GDB now supports a negative repeat count in the 'x' command to examine
2795 memory backward from the given address. For example:
2798 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2799 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2800 (gdb) x/-5i 0x0000000000400580
2801 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2802 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2803 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2804 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2805 0x40057b <main(int, char**)+25>:
2806 callq 0x400536 <Func1(int, char const*)>
2808 * Fortran: Support structures with fields of dynamic types and
2809 arrays of dynamic types.
2811 * The symbol dumping maintenance commands have new syntax.
2812 maint print symbols [-pc address] [--] [filename]
2813 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2814 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2815 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2816 maint print msymbols [-objfile objfile] [--] [filename]
2818 * GDB now supports multibit bitfields and enums in target register
2821 * New Python-based convenience function $_as_string(val), which returns
2822 the textual representation of a value. This function is especially
2823 useful to obtain the text label of an enum value.
2825 * Intel MPX bound violation handling.
2827 Segmentation faults caused by a Intel MPX boundary violation
2828 now display the kind of violation (upper or lower), the memory
2829 address accessed and the memory bounds, along with the usual
2830 signal received and code location.
2834 Program received signal SIGSEGV, Segmentation fault
2835 Upper bound violation while accessing address 0x7fffffffc3b3
2836 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2837 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2839 * Rust language support.
2840 GDB now supports debugging programs written in the Rust programming
2841 language. See https://www.rust-lang.org/ for more information about
2844 * Support for running interpreters on specified input/output devices
2846 GDB now supports a new mechanism that allows frontends to provide
2847 fully featured GDB console views, as a better alternative to
2848 building such views on top of the "-interpreter-exec console"
2849 command. See the new "new-ui" command below. With that command,
2850 frontends can now start GDB in the traditional command-line mode
2851 running in an embedded terminal emulator widget, and create a
2852 separate MI interpreter running on a specified i/o device. In this
2853 way, GDB handles line editing, history, tab completion, etc. in the
2854 console all by itself, and the GUI uses the separate MI interpreter
2855 for its own control and synchronization, invisible to the command
2858 * The "catch syscall" command catches groups of related syscalls.
2860 The "catch syscall" command now supports catching a group of related
2861 syscalls using the 'group:' or 'g:' prefix.
2866 skip -gfile file-glob-pattern
2867 skip -function function
2868 skip -rfunction regular-expression
2869 A generalized form of the skip command, with new support for
2870 glob-style file names and regular expressions for function names.
2871 Additionally, a file spec and a function spec may now be combined.
2873 maint info line-table REGEXP
2874 Display the contents of GDB's internal line table data structure.
2877 Run any GDB unit tests that were compiled in.
2880 Start a new user interface instance running INTERP as interpreter,
2881 using the TTY file for input/output.
2885 ** gdb.Breakpoint objects have a new attribute "pending", which
2886 indicates whether the breakpoint is pending.
2887 ** Three new breakpoint-related events have been added:
2888 gdb.breakpoint_created, gdb.breakpoint_modified, and
2889 gdb.breakpoint_deleted.
2891 signal-event EVENTID
2892 Signal ("set") the given MS-Windows event object. This is used in
2893 conjunction with the Windows JIT debugging (AeDebug) support, where
2894 the OS suspends a crashing process until a debugger can attach to
2895 it. Resuming the crashing process, in order to debug it, is done by
2896 signalling an event.
2898 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2899 was added in GDBserver, including JIT compiling fast tracepoint's
2900 conditional expression bytecode into native code.
2902 * Support for various remote target protocols and ROM monitors has
2905 target m32rsdi Remote M32R debugging over SDI
2906 target mips MIPS remote debugging protocol
2907 target pmon PMON ROM monitor
2908 target ddb NEC's DDB variant of PMON for Vr4300
2909 target rockhopper NEC RockHopper variant of PMON
2910 target lsi LSI variant of PMO
2912 * Support for tracepoints and fast tracepoints on powerpc-linux,
2913 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2914 including JIT compiling fast tracepoint's conditional expression
2915 bytecode into native code.
2917 * MI async record =record-started now includes the method and format used for
2918 recording. For example:
2920 =record-started,thread-group="i1",method="btrace",format="bts"
2922 * MI async record =thread-selected now includes the frame field. For example:
2924 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2928 Andes NDS32 nds32*-*-elf
2930 *** Changes in GDB 7.11
2932 * GDB now supports debugging kernel-based threads on FreeBSD.
2934 * Per-inferior thread numbers
2936 Thread numbers are now per inferior instead of global. If you're
2937 debugging multiple inferiors, GDB displays thread IDs using a
2938 qualified INF_NUM.THR_NUM form. For example:
2942 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2943 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2944 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2945 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2947 As consequence, thread numbers as visible in the $_thread
2948 convenience variable and in Python's InferiorThread.num attribute
2949 are no longer unique between inferiors.
2951 GDB now maintains a second thread ID per thread, referred to as the
2952 global thread ID, which is the new equivalent of thread numbers in
2953 previous releases. See also $_gthread below.
2955 For backwards compatibility, MI's thread IDs always refer to global
2958 * Commands that accept thread IDs now accept the qualified
2959 INF_NUM.THR_NUM form as well. For example:
2962 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2965 * In commands that accept a list of thread IDs, you can now refer to
2966 all threads of an inferior using a star wildcard. GDB accepts
2967 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2968 refer to all threads of the current inferior. For example, "info
2971 * You can use "info threads -gid" to display the global thread ID of
2974 * The new convenience variable $_gthread holds the global number of
2977 * The new convenience variable $_inferior holds the number of the
2980 * GDB now displays the ID and name of the thread that hit a breakpoint
2981 or received a signal, if your program is multi-threaded. For
2984 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2985 Thread 1 "main" received signal SIGINT, Interrupt.
2987 * Record btrace now supports non-stop mode.
2989 * Support for tracepoints on aarch64-linux was added in GDBserver.
2991 * The 'record instruction-history' command now indicates speculative execution
2992 when using the Intel Processor Trace recording format.
2994 * GDB now allows users to specify explicit locations, bypassing
2995 the linespec parser. This feature is also available to GDB/MI
2998 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2999 GDB now is able to debug both AArch64 applications and ARM applications
3002 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
3003 including JIT compiling fast tracepoint's conditional expression bytecode
3006 * GDB now supports displaced stepping on AArch64 GNU/Linux.
3008 * "info threads", "info inferiors", "info display", "info checkpoints"
3009 and "maint info program-spaces" now list the corresponding items in
3010 ascending ID order, for consistency with all other "info" commands.
3012 * In Ada, the overloads selection menu has been enhanced to display the
3013 parameter types and the return types for the matching overloaded subprograms.
3017 maint set target-non-stop (on|off|auto)
3018 maint show target-non-stop
3019 Control whether GDB targets always operate in non-stop mode even if
3020 "set non-stop" is "off". The default is "auto", meaning non-stop
3021 mode is enabled if supported by the target.
3023 maint set bfd-sharing
3024 maint show bfd-sharing
3025 Control the reuse of bfd objects.
3028 show debug bfd-cache
3029 Control display of debugging info regarding bfd caching.
3033 Control display of debugging info regarding FreeBSD threads.
3035 set remote multiprocess-extensions-packet
3036 show remote multiprocess-extensions-packet
3037 Set/show the use of the remote protocol multiprocess extensions.
3039 set remote thread-events
3040 show remote thread-events
3041 Set/show the use of thread create/exit events.
3043 set ada print-signatures on|off
3044 show ada print-signatures"
3045 Control whether parameter types and return types are displayed in overloads
3046 selection menus. It is activated (@code{on}) by default.
3050 Controls the maximum size of memory, in bytes, that GDB will
3051 allocate for value contents. Prevents incorrect programs from
3052 causing GDB to allocate overly large buffers. Default is 64k.
3054 * The "disassemble" command accepts a new modifier: /s.
3055 It prints mixed source+disassembly like /m with two differences:
3056 - disassembled instructions are now printed in program order, and
3057 - and source for all relevant files is now printed.
3058 The "/m" option is now considered deprecated: its "source-centric"
3059 output hasn't proved useful in practice.
3061 * The "record instruction-history" command accepts a new modifier: /s.
3062 It behaves exactly like /m and prints mixed source+disassembly.
3064 * The "set scheduler-locking" command supports a new mode "replay".
3065 It behaves like "off" in record mode and like "on" in replay mode.
3067 * Support for various ROM monitors has been removed:
3069 target dbug dBUG ROM monitor for Motorola ColdFire
3070 target picobug Motorola picobug monitor
3071 target dink32 DINK32 ROM monitor for PowerPC
3072 target m32r Renesas M32R/D ROM monitor
3073 target mon2000 mon2000 ROM monitor
3074 target ppcbug PPCBUG ROM monitor for PowerPC
3076 * Support for reading/writing memory and extracting values on architectures
3077 whose memory is addressable in units of any integral multiple of 8 bits.
3080 Allows to break when an Ada exception is handled.
3082 * New remote packets
3085 Indicates that an exec system call was executed.
3087 exec-events feature in qSupported
3088 The qSupported packet allows GDB to request support for exec
3089 events using the new 'gdbfeature' exec-event, and the qSupported
3090 response can contain the corresponding 'stubfeature'. Set and
3091 show commands can be used to display whether these features are enabled.
3094 Equivalent to interrupting with the ^C character, but works in
3097 thread created stop reason (T05 create:...)
3098 Indicates that the thread was just created and is stopped at entry.
3100 thread exit stop reply (w exitcode;tid)
3101 Indicates that the thread has terminated.
3104 Enables/disables thread create and exit event reporting. For
3105 example, this is used in non-stop mode when GDB stops a set of
3106 threads and synchronously waits for the their corresponding stop
3107 replies. Without exit events, if one of the threads exits, GDB
3108 would hang forever not knowing that it should no longer expect a
3109 stop for that same thread.
3112 Indicates that there are no resumed threads left in the target (all
3113 threads are stopped). The remote stub reports support for this stop
3114 reply to GDB's qSupported query.
3117 Enables/disables catching syscalls from the inferior process.
3118 The remote stub reports support for this packet to GDB's qSupported query.
3120 syscall_entry stop reason
3121 Indicates that a syscall was just called.
3123 syscall_return stop reason
3124 Indicates that a syscall just returned.
3126 * Extended-remote exec events
3128 ** GDB now has support for exec events on extended-remote Linux targets.
3129 For such targets with Linux kernels 2.5.46 and later, this enables
3130 follow-exec-mode and exec catchpoints.
3132 set remote exec-event-feature-packet
3133 show remote exec-event-feature-packet
3134 Set/show the use of the remote exec event feature.
3136 * Thread names in remote protocol
3138 The reply to qXfer:threads:read may now include a name attribute for each
3141 * Target remote mode fork and exec events
3143 ** GDB now has support for fork and exec events on target remote mode
3144 Linux targets. For such targets with Linux kernels 2.5.46 and later,
3145 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
3146 fork and exec catchpoints.
3148 * Remote syscall events
3150 ** GDB now has support for catch syscall on remote Linux targets,
3151 currently enabled on x86/x86_64 architectures.
3153 set remote catch-syscall-packet
3154 show remote catch-syscall-packet
3155 Set/show the use of the remote catch syscall feature.
3159 ** The -var-set-format command now accepts the zero-hexadecimal
3160 format. It outputs data in hexadecimal format with zero-padding on the
3165 ** gdb.InferiorThread objects have a new attribute "global_num",
3166 which refers to the thread's global thread ID. The existing
3167 "num" attribute now refers to the thread's per-inferior number.
3168 See "Per-inferior thread numbers" above.
3169 ** gdb.InferiorThread objects have a new attribute "inferior", which
3170 is the Inferior object the thread belongs to.
3172 *** Changes in GDB 7.10
3174 * Support for process record-replay and reverse debugging on aarch64*-linux*
3175 targets has been added. GDB now supports recording of A64 instruction set
3176 including advance SIMD instructions.
3178 * Support for Sun's version of the "stabs" debug file format has been removed.
3180 * GDB now honors the content of the file /proc/PID/coredump_filter
3181 (PID is the process ID) on GNU/Linux systems. This file can be used
3182 to specify the types of memory mappings that will be included in a
3183 corefile. For more information, please refer to the manual page of
3184 "core(5)". GDB also has a new command: "set use-coredump-filter
3185 on|off". It allows to set whether GDB will read the content of the
3186 /proc/PID/coredump_filter file when generating a corefile.
3188 * The "info os" command on GNU/Linux can now display information on
3190 "info os cpus" Listing of all cpus/cores on the system
3192 * GDB has two new commands: "set serial parity odd|even|none" and
3193 "show serial parity". These allows to set or show parity for the
3196 * The "info source" command now displays the producer string if it was
3197 present in the debug info. This typically includes the compiler version
3198 and may include things like its command line arguments.
3200 * The "info dll", an alias of the "info sharedlibrary" command,
3201 is now available on all platforms.
3203 * Directory names supplied to the "set sysroot" commands may be
3204 prefixed with "target:" to tell GDB to access shared libraries from
3205 the target system, be it local or remote. This replaces the prefix
3206 "remote:". The default sysroot has been changed from "" to
3207 "target:". "remote:" is automatically converted to "target:" for
3208 backward compatibility.
3210 * The system root specified by "set sysroot" will be prepended to the
3211 filename of the main executable (if reported to GDB as absolute by
3212 the operating system) when starting processes remotely, and when
3213 attaching to already-running local or remote processes.
3215 * GDB now supports automatic location and retrieval of executable
3216 files from remote targets. Remote debugging can now be initiated
3217 using only a "target remote" or "target extended-remote" command
3218 (no "set sysroot" or "file" commands are required). See "New remote
3221 * The "dump" command now supports verilog hex format.
3223 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
3225 * On GNU/Linux, GDB and gdbserver are now able to access executable
3226 and shared library files without a "set sysroot" command when
3227 attaching to processes running in different mount namespaces from
3228 the debugger. This makes it possible to attach to processes in
3229 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
3230 See "New remote packets" below.
3232 * The "tui reg" command now provides completion for all of the
3233 available register groups, including target specific groups.
3235 * The HISTSIZE environment variable is no longer read when determining
3236 the size of GDB's command history. GDB now instead reads the dedicated
3237 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
3238 disables truncation of command history. Non-numeric values of GDBHISTSIZE
3243 ** Memory ports can now be unbuffered.
3247 ** gdb.Objfile objects have a new attribute "username",
3248 which is the name of the objfile as specified by the user,
3249 without, for example, resolving symlinks.
3250 ** You can now write frame unwinders in Python.
3251 ** gdb.Type objects have a new method "optimized_out",
3252 returning optimized out gdb.Value instance of this type.
3253 ** gdb.Value objects have new methods "reference_value" and
3254 "const_value" which return a reference to the value and a
3255 "const" version of the value respectively.
3259 maint print symbol-cache
3260 Print the contents of the symbol cache.
3262 maint print symbol-cache-statistics
3263 Print statistics of symbol cache usage.
3265 maint flush-symbol-cache
3266 Flush the contents of the symbol cache.
3270 Start branch trace recording using Branch Trace Store (BTS) format.
3273 Evaluate expression by using the compiler and print result.
3277 Explicit commands for enabling and disabling tui mode.
3280 set mpx bound on i386 and amd64
3281 Support for bound table investigation on Intel MPX enabled applications.
3285 Start branch trace recording using Intel Processor Trace format.
3288 Print information about branch tracing internals.
3290 maint btrace packet-history
3291 Print the raw branch tracing data.
3293 maint btrace clear-packet-history
3294 Discard the stored raw branch tracing data.
3297 Discard all branch tracing data. It will be fetched and processed
3298 anew by the next "record" command.
3303 Renamed from "set debug dwarf2-die".
3304 show debug dwarf-die
3305 Renamed from "show debug dwarf2-die".
3307 set debug dwarf-read
3308 Renamed from "set debug dwarf2-read".
3309 show debug dwarf-read
3310 Renamed from "show debug dwarf2-read".
3312 maint set dwarf always-disassemble
3313 Renamed from "maint set dwarf2 always-disassemble".
3314 maint show dwarf always-disassemble
3315 Renamed from "maint show dwarf2 always-disassemble".
3317 maint set dwarf max-cache-age
3318 Renamed from "maint set dwarf2 max-cache-age".
3319 maint show dwarf max-cache-age
3320 Renamed from "maint show dwarf2 max-cache-age".
3322 set debug dwarf-line
3323 show debug dwarf-line
3324 Control display of debugging info regarding DWARF line processing.
3327 show max-completions
3328 Set the maximum number of candidates to be considered during
3329 completion. The default value is 200. This limit allows GDB
3330 to avoid generating large completion lists, the computation of
3331 which can cause the debugger to become temporarily unresponsive.
3333 set history remove-duplicates
3334 show history remove-duplicates
3335 Control the removal of duplicate history entries.
3337 maint set symbol-cache-size
3338 maint show symbol-cache-size
3339 Control the size of the symbol cache.
3341 set|show record btrace bts buffer-size
3342 Set and show the size of the ring buffer used for branch tracing in
3344 The obtained size may differ from the requested size. Use "info
3345 record" to see the obtained buffer size.
3347 set debug linux-namespaces
3348 show debug linux-namespaces
3349 Control display of debugging info regarding Linux namespaces.
3351 set|show record btrace pt buffer-size
3352 Set and show the size of the ring buffer used for branch tracing in
3353 Intel Processor Trace format.
3354 The obtained size may differ from the requested size. Use "info
3355 record" to see the obtained buffer size.
3357 maint set|show btrace pt skip-pad
3358 Set and show whether PAD packets are skipped when computing the
3361 * The command 'thread apply all' can now support new option '-ascending'
3362 to call its specified command for all threads in ascending order.
3364 * Python/Guile scripting
3366 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3367 special section named `.debug_gdb_scripts'.
3369 * New remote packets
3371 qXfer:btrace-conf:read
3372 Return the branch trace configuration for the current thread.
3374 Qbtrace-conf:bts:size
3375 Set the requested ring buffer size for branch tracing in BTS format.
3378 Enable Intel Processor Trace-based branch tracing for the current
3379 process. The remote stub reports support for this packet to GDB's
3382 Qbtrace-conf:pt:size
3383 Set the requested ring buffer size for branch tracing in Intel Processor
3387 Indicates a memory breakpoint instruction was executed, irrespective
3388 of whether it was GDB that planted the breakpoint or the breakpoint
3389 is hardcoded in the program. This is required for correct non-stop
3393 Indicates the target stopped for a hardware breakpoint. This is
3394 required for correct non-stop mode operation.
3397 Return information about files on the remote system.
3399 qXfer:exec-file:read
3400 Return the full absolute name of the file that was executed to
3401 create a process running on the remote system.
3404 Select the filesystem on which vFile: operations with filename
3405 arguments will operate. This is required for GDB to be able to
3406 access files on remote targets where the remote stub does not
3407 share a common filesystem with the inferior(s).
3410 Indicates that a fork system call was executed.
3413 Indicates that a vfork system call was executed.
3415 vforkdone stop reason
3416 Indicates that a vfork child of the specified process has executed
3417 an exec or exit, allowing the vfork parent to resume execution.
3419 fork-events and vfork-events features in qSupported
3420 The qSupported packet allows GDB to request support for fork and
3421 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3422 and the qSupported response can contain the corresponding
3423 'stubfeatures'. Set and show commands can be used to display
3424 whether these features are enabled.
3426 * Extended-remote fork events
3428 ** GDB now has support for fork events on extended-remote Linux
3429 targets. For targets with Linux kernels 2.5.60 and later, this
3430 enables follow-fork-mode and detach-on-fork for both fork and
3431 vfork, as well as fork and vfork catchpoints.
3433 * The info record command now shows the recording format and the
3434 branch tracing configuration for the current thread when using
3435 the btrace record target.
3436 For the BTS format, it shows the ring buffer size.
3438 * GDB now has support for DTrace USDT (Userland Static Defined
3439 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3441 * GDB now supports access to vector registers on S/390 GNU/Linux
3444 * Removed command line options
3446 -xdb HP-UX XDB compatibility mode.
3448 * Removed targets and native configurations
3450 HP/PA running HP-UX hppa*-*-hpux*
3451 Itanium running HP-UX ia64-*-hpux*
3453 * New configure options
3456 This configure option allows the user to build GDB with support for
3457 Intel Processor Trace (default: auto). This requires libipt.
3459 --with-libipt-prefix=PATH
3460 Specify the path to the version of libipt that GDB should use.
3461 $PATH/include should contain the intel-pt.h header and
3462 $PATH/lib should contain the libipt.so library.
3464 *** Changes in GDB 7.9.1
3468 ** Xmethods can now specify a result type.
3470 *** Changes in GDB 7.9
3472 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3476 ** You can now access frame registers from Python scripts.
3477 ** New attribute 'producer' for gdb.Symtab objects.
3478 ** gdb.Objfile objects have a new attribute "progspace",
3479 which is the gdb.Progspace object of the containing program space.
3480 ** gdb.Objfile objects have a new attribute "owner".
3481 ** gdb.Objfile objects have a new attribute "build_id",
3482 which is the build ID generated when the file was built.
3483 ** gdb.Objfile objects have a new method "add_separate_debug_file".
3484 ** A new event "gdb.clear_objfiles" has been added, triggered when
3485 selecting a new file to debug.
3486 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3487 ** New function gdb.lookup_objfile.
3489 New events which are triggered when GDB modifies the state of the
3492 ** gdb.events.inferior_call_pre: Function call is about to be made.
3493 ** gdb.events.inferior_call_post: Function call has just been made.
3494 ** gdb.events.memory_changed: A memory location has been altered.
3495 ** gdb.events.register_changed: A register has been altered.
3497 * New Python-based convenience functions:
3499 ** $_caller_is(name [, number_of_frames])
3500 ** $_caller_matches(regexp [, number_of_frames])
3501 ** $_any_caller_is(name [, number_of_frames])
3502 ** $_any_caller_matches(regexp [, number_of_frames])
3504 * GDB now supports the compilation and injection of source code into
3505 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
3506 to compile the source code to object code, and if successful, inject
3507 and execute that code within the current context of the inferior.
3508 Currently the C language is supported. The commands used to
3509 interface with this new feature are:
3511 compile code [-raw|-r] [--] [source code]
3512 compile file [-raw|-r] filename
3516 demangle [-l language] [--] name
3517 Demangle "name" in the specified language, or the current language
3518 if elided. This command is renamed from the "maint demangle" command.
3519 The latter is kept as a no-op to avoid "maint demangle" being interpreted
3520 as "maint demangler-warning".
3522 queue-signal signal-name-or-number
3523 Queue a signal to be delivered to the thread when it is resumed.
3525 add-auto-load-scripts-directory directory
3526 Add entries to the list of directories from which to load auto-loaded
3529 maint print user-registers
3530 List all currently available "user" registers.
3532 compile code [-r|-raw] [--] [source code]
3533 Compile, inject, and execute in the inferior the executable object
3534 code produced by compiling the provided source code.
3536 compile file [-r|-raw] filename
3537 Compile and inject into the inferior the executable object code
3538 produced by compiling the source code stored in the filename
3541 * On resume, GDB now always passes the signal the program had stopped
3542 for to the thread the signal was sent to, even if the user changed
3543 threads before resuming. Previously GDB would often (but not
3544 always) deliver the signal to the thread that happens to be current
3547 * Conversely, the "signal" command now consistently delivers the
3548 requested signal to the current thread. GDB now asks for
3549 confirmation if the program had stopped for a signal and the user
3550 switched threads meanwhile.
3552 * "breakpoint always-inserted" modes "off" and "auto" merged.
3554 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3555 won't remove breakpoints from the target until all threads stop,
3556 even in non-stop mode. The "auto" mode has been removed, and "off"
3557 is now the default mode.
3561 set debug symbol-lookup
3562 show debug symbol-lookup
3563 Control display of debugging info regarding symbol lookup.
3567 ** The -list-thread-groups command outputs an exit-code field for
3568 inferiors that have exited.
3572 MIPS SDE mips*-sde*-elf*
3576 Support for these obsolete configurations has been removed.
3578 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
3579 SGI Irix-5.x mips-*-irix5*
3580 SGI Irix-6.x mips-*-irix6*
3581 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
3582 VAX running Ultrix vax-*-ultrix*
3584 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3585 and "assf"), have been removed. Use the "sharedlibrary" command, or
3586 its alias "share", instead.
3588 *** Changes in GDB 7.8
3590 * New command line options
3593 This is an alias for the --data-directory option.
3595 * GDB supports printing and modifying of variable length automatic arrays
3596 as specified in ISO C99.
3598 * The ARM simulator now supports instruction level tracing
3599 with or without disassembly.
3603 GDB now has support for scripting using Guile. Whether this is
3604 available is determined at configure time.
3605 Guile version 2.0 or greater is required.
3606 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3608 * New commands (for set/show, see "New options" below)
3612 Invoke CODE by passing it to the Guile interpreter.
3616 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3618 info auto-load guile-scripts [regexp]
3619 Print the list of automatically loaded Guile scripts.
3621 * The source command is now capable of sourcing Guile scripts.
3622 This feature is dependent on the debugger being built with Guile support.
3626 set print symbol-loading (off|brief|full)
3627 show print symbol-loading
3628 Control whether to print informational messages when loading symbol
3629 information for a file. The default is "full", but when debugging
3630 programs with large numbers of shared libraries the amount of output
3631 becomes less useful.
3633 set guile print-stack (none|message|full)
3634 show guile print-stack
3635 Show a stack trace when an error is encountered in a Guile script.
3637 set auto-load guile-scripts (on|off)
3638 show auto-load guile-scripts
3639 Control auto-loading of Guile script files.
3641 maint ada set ignore-descriptive-types (on|off)
3642 maint ada show ignore-descriptive-types
3643 Control whether the debugger should ignore descriptive types in Ada
3644 programs. The default is not to ignore the descriptive types. See
3645 the user manual for more details on descriptive types and the intended
3646 usage of this option.
3648 set auto-connect-native-target
3650 Control whether GDB is allowed to automatically connect to the
3651 native target for the run, attach, etc. commands when not connected
3652 to any target yet. See also "target native" below.
3654 set record btrace replay-memory-access (read-only|read-write)
3655 show record btrace replay-memory-access
3656 Control what memory accesses are allowed during replay.
3658 maint set target-async (on|off)
3659 maint show target-async
3660 This controls whether GDB targets operate in synchronous or
3661 asynchronous mode. Normally the default is asynchronous, if it is
3662 available; but this can be changed to more easily debug problems
3663 occurring only in synchronous mode.
3665 set mi-async (on|off)
3667 Control whether MI asynchronous mode is preferred. This supersedes
3668 "set target-async" of previous GDB versions.
3670 * "set target-async" is deprecated as a CLI option and is now an alias
3671 for "set mi-async" (only puts MI into async mode).
3673 * Background execution commands (e.g., "c&", "s&", etc.) are now
3674 possible ``out of the box'' if the target supports them. Previously
3675 the user would need to explicitly enable the possibility with the
3676 "set target-async on" command.
3678 * New features in the GDB remote stub, GDBserver
3680 ** New option --debug-format=option1[,option2,...] allows one to add
3681 additional text to each output. At present only timestamps
3682 are supported: --debug-format=timestamps.
3683 Timestamps can also be turned on with the
3684 "monitor set debug-format timestamps" command from GDB.
3686 * The 'record instruction-history' command now starts counting instructions
3687 at one. This also affects the instruction ranges reported by the
3688 'record function-call-history' command when given the /i modifier.
3690 * The command 'record function-call-history' supports a new modifier '/c' to
3691 indent the function names based on their call stack depth.
3692 The fields for the '/i' and '/l' modifier have been reordered.
3693 The source line range is now prefixed with 'at'.
3694 The instruction range is now prefixed with 'inst'.
3695 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3696 "record instruction-history" and "list" commands.
3698 * The ranges given as arguments to the 'record function-call-history' and
3699 'record instruction-history' commands are now inclusive.
3701 * The btrace record target now supports the 'record goto' command.
3702 For locations inside the execution trace, the back trace is computed
3703 based on the information stored in the execution trace.
3705 * The btrace record target supports limited reverse execution and replay.
3706 The target does not record data and therefore does not allow reading
3707 memory or registers.
3709 * The "catch syscall" command now works on s390*-linux* targets.
3711 * The "compare-sections" command is no longer specific to target
3712 remote. It now works with all targets.
3714 * All native targets are now consistently called "native".
3715 Consequently, the "target child", "target GNU", "target djgpp",
3716 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3717 commands have been replaced with "target native". The QNX/NTO port
3718 leaves the "procfs" target in place and adds a "native" target for
3719 consistency with other ports. The impact on users should be minimal
3720 as these commands previously either throwed an error, or were
3721 no-ops. The target's name is visible in the output of the following
3722 commands: "help target", "info target", "info files", "maint print
3725 * The "target native" command now connects to the native target. This
3726 can be used to launch native programs even when "set
3727 auto-connect-native-target" is set to off.
3729 * GDB now supports access to Intel MPX registers on GNU/Linux.
3731 * Support for Intel AVX-512 registers on GNU/Linux.
3732 Support displaying and modifying Intel AVX-512 registers
3733 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3735 * New remote packets
3737 qXfer:btrace:read's annex
3738 The qXfer:btrace:read packet supports a new annex 'delta' to read
3739 branch trace incrementally.
3743 ** Valid Python operations on gdb.Value objects representing
3744 structs/classes invoke the corresponding overloaded operators if
3746 ** New `Xmethods' feature in the Python API. Xmethods are
3747 additional methods or replacements for existing methods of a C++
3748 class. This feature is useful for those cases where a method
3749 defined in C++ source code could be inlined or optimized out by
3750 the compiler, making it unavailable to GDB.
3753 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3755 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3756 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3757 its alias "share", instead.
3759 * The commands "set remotebaud" and "show remotebaud" are no longer
3760 supported. Use "set serial baud" and "show serial baud" (respectively)
3765 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3766 target-async". The latter is left as a deprecated alias of the
3767 former for backward compatibility. If the target supports it,
3768 CLI background execution commands are now always possible by
3769 default, independently of whether the frontend stated a
3770 preference for asynchronous execution with "-gdb-set mi-async".
3771 Previously "-gdb-set target-async off" affected both MI execution
3772 commands and CLI execution commands.
3774 *** Changes in GDB 7.7
3776 * Improved support for process record-replay and reverse debugging on
3777 arm*-linux* targets. Support for thumb32 and syscall instruction
3778 recording has been added.
3780 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3782 * GDB now supports Fission DWP file format version 2.
3783 http://gcc.gnu.org/wiki/DebugFission
3785 * New convenience function "$_isvoid", to check whether an expression
3786 is void. A void expression is an expression where the type of the
3787 result is "void". For example, some convenience variables may be
3788 "void" when evaluated (e.g., "$_exitcode" before the execution of
3789 the program being debugged; or an undefined convenience variable).
3790 Another example, when calling a function whose return type is
3793 * The "maintenance print objfiles" command now takes an optional regexp.
3795 * The "catch syscall" command now works on arm*-linux* targets.
3797 * GDB now consistently shows "<not saved>" when printing values of
3798 registers the debug info indicates have not been saved in the frame
3799 and there's nowhere to retrieve them from
3800 (callee-saved/call-clobbered registers):
3805 (gdb) info registers rax
3808 Before, the former would print "<optimized out>", and the latter
3809 "*value not available*".
3811 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3816 ** Frame filters and frame decorators have been added.
3817 ** Temporary breakpoints are now supported.
3818 ** Line tables representation has been added.
3819 ** New attribute 'parent_type' for gdb.Field objects.
3820 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3821 ** New attribute 'name' for gdb.Type objects.
3825 Nios II ELF nios2*-*-elf
3826 Nios II GNU/Linux nios2*-*-linux
3827 Texas Instruments MSP430 msp430*-*-elf
3829 * Removed native configurations
3831 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3832 been removed. ELF variants of these configurations are kept supported.
3834 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3835 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3836 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3837 i[34567]86-*-openbsd3.[0-3]
3838 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3839 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3840 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3844 Like "catch throw", but catches a re-thrown exception.
3845 maint check-psymtabs
3846 Renamed from old "maint check-symtabs".
3848 Perform consistency checks on symtabs.
3849 maint expand-symtabs
3850 Expand symtabs matching an optional regexp.
3853 Display the details of GDB configure-time options.
3855 maint set|show per-command
3856 maint set|show per-command space
3857 maint set|show per-command time
3858 maint set|show per-command symtab
3859 Enable display of per-command gdb resource usage.
3861 remove-symbol-file FILENAME
3862 remove-symbol-file -a ADDRESS
3863 Remove a symbol file added via add-symbol-file. The file to remove
3864 can be identified by its filename or by an address that lies within
3865 the boundaries of this symbol file in memory.
3868 info exceptions REGEXP
3869 Display the list of Ada exceptions defined in the program being
3870 debugged. If provided, only the exceptions whose names match REGEXP
3875 set debug symfile off|on
3877 Control display of debugging info regarding reading symbol files and
3878 symbol tables within those files
3880 set print raw frame-arguments
3881 show print raw frame-arguments
3882 Set/show whether to print frame arguments in raw mode,
3883 disregarding any defined pretty-printers.
3885 set remote trace-status-packet
3886 show remote trace-status-packet
3887 Set/show the use of remote protocol qTStatus packet.
3891 Control display of debugging messages related to Nios II targets.
3895 Control whether target-assisted range stepping is enabled.
3897 set startup-with-shell
3898 show startup-with-shell
3899 Specifies whether Unix child processes are started via a shell or
3904 Use the target memory cache for accesses to the code segment. This
3905 improves performance of remote debugging (particularly disassembly).
3907 * You can now use a literal value 'unlimited' for options that
3908 interpret 0 or -1 as meaning "unlimited". E.g., "set
3909 trace-buffer-size unlimited" is now an alias for "set
3910 trace-buffer-size -1" and "set height unlimited" is now an alias for
3913 * The "set debug symtab-create" debugging option of GDB has been changed to
3914 accept a verbosity level. 0 means "off", 1 provides basic debugging
3915 output, and values of 2 or greater provides more verbose output.
3917 * New command-line options
3919 Display the details of GDB configure-time options.
3921 * The command 'tsave' can now support new option '-ctf' to save trace
3922 buffer in Common Trace Format.
3924 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3927 * GDB now implements the C++ 'typeid' operator.
3929 * The new convenience variable $_exception holds the exception being
3930 thrown or caught at an exception-related catchpoint.
3932 * The exception-related catchpoints, like "catch throw", now accept a
3933 regular expression which can be used to filter exceptions by type.
3935 * The new convenience variable $_exitsignal is automatically set to
3936 the terminating signal number when the program being debugged dies
3937 due to an uncaught signal.
3941 ** All MI commands now accept an optional "--language" option.
3942 Support for this feature can be verified by using the "-list-features"
3943 command, which should contain "language-option".
3945 ** The new command -info-gdb-mi-command allows the user to determine
3946 whether a GDB/MI command is supported or not.
3948 ** The "^error" result record returned when trying to execute an undefined
3949 GDB/MI command now provides a variable named "code" whose content is the
3950 "undefined-command" error code. Support for this feature can be verified
3951 by using the "-list-features" command, which should contain
3952 "undefined-command-error-code".
3954 ** The -trace-save MI command can optionally save trace buffer in Common
3957 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3959 ** The command -data-list-register-values now accepts an optional
3960 "--skip-unavailable" option. When used, only the available registers
3963 ** The new command -trace-frame-collected dumps collected variables,
3964 computed expressions, tvars, memory and registers in a traceframe.
3966 ** The commands -stack-list-locals, -stack-list-arguments and
3967 -stack-list-variables now accept an option "--skip-unavailable".
3968 When used, only the available locals or arguments are displayed.
3970 ** The -exec-run command now accepts an optional "--start" option.
3971 When used, the command follows the same semantics as the "start"
3972 command, stopping the program's execution at the start of its
3973 main subprogram. Support for this feature can be verified using
3974 the "-list-features" command, which should contain
3975 "exec-run-start-option".
3977 ** The new commands -catch-assert and -catch-exceptions insert
3978 catchpoints stopping the program when Ada exceptions are raised.
3980 ** The new command -info-ada-exceptions provides the equivalent of
3981 the new "info exceptions" command.
3983 * New system-wide configuration scripts
3984 A GDB installation now provides scripts suitable for use as system-wide
3985 configuration scripts for the following systems:
3989 * GDB now supports target-assigned range stepping with remote targets.
3990 This improves the performance of stepping source lines by reducing
3991 the number of control packets from/to GDB. See "New remote packets"
3994 * GDB now understands the element 'tvar' in the XML traceframe info.
3995 It has the id of the collected trace state variables.
3997 * On S/390 targets that provide the transactional-execution feature,
3998 the program interruption transaction diagnostic block (TDB) is now
3999 represented as a number of additional "registers" in GDB.
4001 * New remote packets
4005 The vCont packet supports a new 'r' action, that tells the remote
4006 stub to step through an address range itself, without GDB
4007 involvemement at each single-step.
4009 qXfer:libraries-svr4:read's annex
4010 The previously unused annex of the qXfer:libraries-svr4:read packet
4011 is now used to support passing an argument list. The remote stub
4012 reports support for this argument list to GDB's qSupported query.
4013 The defined arguments are "start" and "prev", used to reduce work
4014 necessary for library list updating, resulting in significant
4017 * New features in the GDB remote stub, GDBserver
4019 ** GDBserver now supports target-assisted range stepping. Currently
4020 enabled on x86/x86_64 GNU/Linux targets.
4022 ** GDBserver now adds element 'tvar' in the XML in the reply to
4023 'qXfer:traceframe-info:read'. It has the id of the collected
4024 trace state variables.
4026 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
4029 * New 'z' formatter for printing and examining memory, this displays the
4030 value as hexadecimal zero padded on the left to the size of the type.
4032 * GDB can now use Windows x64 unwinding data.
4034 * The "set remotebaud" command has been replaced by "set serial baud".
4035 Similarly, "show remotebaud" has been replaced by "show serial baud".
4036 The "set remotebaud" and "show remotebaud" commands are still available
4037 to provide backward compatibility with older versions of GDB.
4039 *** Changes in GDB 7.6
4041 * Target record has been renamed to record-full.
4042 Record/replay is now enabled with the "record full" command.
4043 This also affects settings that are associated with full record/replay
4044 that have been moved from "set/show record" to "set/show record full":
4046 set|show record full insn-number-max
4047 set|show record full stop-at-limit
4048 set|show record full memory-query
4050 * A new record target "record-btrace" has been added. The new target
4051 uses hardware support to record the control-flow of a process. It
4052 does not support replaying the execution, but it implements the
4053 below new commands for investigating the recorded execution log.
4054 This new recording method can be enabled using:
4058 The "record-btrace" target is only available on Intel Atom processors
4059 and requires a Linux kernel 2.6.32 or later.
4061 * Two new commands have been added for record/replay to give information
4062 about the recorded execution without having to replay the execution.
4063 The commands are only supported by "record btrace".
4065 record instruction-history prints the execution history at
4066 instruction granularity
4068 record function-call-history prints the execution history at
4069 function granularity
4071 * New native configurations
4073 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
4074 FreeBSD/powerpc powerpc*-*-freebsd
4075 x86_64/Cygwin x86_64-*-cygwin*
4076 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
4080 ARM AArch64 aarch64*-*-elf
4081 ARM AArch64 GNU/Linux aarch64*-*-linux
4082 Lynx 178 PowerPC powerpc-*-lynx*178
4083 x86_64/Cygwin x86_64-*-cygwin*
4084 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
4086 * If the configured location of system.gdbinit file (as given by the
4087 --with-system-gdbinit option at configure time) is in the
4088 data-directory (as specified by --with-gdb-datadir at configure
4089 time) or in one of its subdirectories, then GDB will look for the
4090 system-wide init file in the directory specified by the
4091 --data-directory command-line option.
4093 * New command line options:
4095 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
4096 other initialization files, unlike -nx which disables all of them.
4098 * Removed command line options
4100 -epoch This was used by the gdb mode in Epoch, an ancient fork of
4103 * The 'ptype' and 'whatis' commands now accept an argument to control
4106 * 'info proc' now works on some core files.
4110 ** Vectors can be created with gdb.Type.vector.
4112 ** Python's atexit.register now works in GDB.
4114 ** Types can be pretty-printed via a Python API.
4116 ** Python 3 is now supported (in addition to Python 2.4 or later)
4118 ** New class gdb.Architecture exposes GDB's internal representation
4119 of architecture in the Python API.
4121 ** New method Frame.architecture returns the gdb.Architecture object
4122 corresponding to the frame's architecture.
4124 * New Python-based convenience functions:
4126 ** $_memeq(buf1, buf2, length)
4127 ** $_streq(str1, str2)
4129 ** $_regex(str, regex)
4131 * The 'cd' command now defaults to using '~' (the home directory) if not
4134 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
4135 default for GCC since November 2000.
4137 * The command 'forward-search' can now be abbreviated as 'fo'.
4139 * The command 'info tracepoints' can now display 'installed on target'
4140 or 'not installed on target' for each non-pending location of tracepoint.
4142 * New configure options
4144 --enable-libmcheck/--disable-libmcheck
4145 By default, development versions are built with -lmcheck on hosts
4146 that support it, in order to help track memory corruption issues.
4147 Release versions, on the other hand, are built without -lmcheck
4148 by default. The --enable-libmcheck/--disable-libmcheck configure
4149 options allow the user to override that default.
4150 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
4151 This configure option allows the user to build GDB with
4152 libbabeltrace using which GDB can read Common Trace Format data.
4154 * New commands (for set/show, see "New options" below)
4157 Catch signals. This is similar to "handle", but allows commands and
4158 conditions to be attached.
4161 List the BFDs known to GDB.
4163 python-interactive [command]
4165 Start a Python interactive prompt, or evaluate the optional command
4166 and print the result of expressions.
4169 "py" is a new alias for "python".
4171 enable type-printer [name]...
4172 disable type-printer [name]...
4173 Enable or disable type printers.
4177 ** For the Renesas Super-H architecture, the "regs" command has been removed
4178 (has been deprecated in GDB 7.5), and "info all-registers" should be used
4183 set print type methods (on|off)
4184 show print type methods
4185 Control whether method declarations are displayed by "ptype".
4186 The default is to show them.
4188 set print type typedefs (on|off)
4189 show print type typedefs
4190 Control whether typedef definitions are displayed by "ptype".
4191 The default is to show them.
4193 set filename-display basename|relative|absolute
4194 show filename-display
4195 Control the way in which filenames is displayed.
4196 The default is "relative", which preserves previous behavior.
4198 set trace-buffer-size
4199 show trace-buffer-size
4200 Request target to change the size of trace buffer.
4202 set remote trace-buffer-size-packet auto|on|off
4203 show remote trace-buffer-size-packet
4204 Control the use of the remote protocol `QTBuffer:size' packet.
4208 Control display of debugging messages related to ARM AArch64.
4211 set debug coff-pe-read
4212 show debug coff-pe-read
4213 Control display of debugging messages related to reading of COFF/PE
4218 Control display of debugging messages related to Mach-O symbols
4221 set debug notification
4222 show debug notification
4223 Control display of debugging info for async remote notification.
4227 ** Command parameter changes are now notified using new async record
4228 "=cmd-param-changed".
4229 ** Trace frame changes caused by command "tfind" are now notified using
4230 new async record "=traceframe-changed".
4231 ** The creation, deletion and modification of trace state variables
4232 are now notified using new async records "=tsv-created",
4233 "=tsv-deleted" and "=tsv-modified".
4234 ** The start and stop of process record are now notified using new
4235 async record "=record-started" and "=record-stopped".
4236 ** Memory changes are now notified using new async record
4238 ** The data-disassemble command response will include a "fullname" field
4239 containing the absolute file name when source has been requested.
4240 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
4241 command, to allow pattern filling of memory areas.
4242 ** New commands "-catch-load"/"-catch-unload" added for intercepting
4243 library load/unload events.
4244 ** The response to breakpoint commands and breakpoint async records
4245 includes an "installed" field containing a boolean state about each
4246 non-pending tracepoint location is whether installed on target or not.
4247 ** Output of the "-trace-status" command includes a "trace-file" field
4248 containing the name of the trace file being examined. This field is
4249 optional, and only present when examining a trace file.
4250 ** The "fullname" field is now always present along with the "file" field,
4251 even if the file cannot be found by GDB.
4253 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4254 You must have the LZMA library available when configuring GDB for this
4255 feature to be enabled. For more information, see:
4256 http://fedoraproject.org/wiki/Features/MiniDebugInfo
4258 * New remote packets
4261 Set the size of trace buffer. The remote stub reports support for this
4262 packet to gdb's qSupported query.
4265 Enable Branch Trace Store (BTS)-based branch tracing for the current
4266 thread. The remote stub reports support for this packet to gdb's
4270 Disable branch tracing for the current thread. The remote stub reports
4271 support for this packet to gdb's qSupported query.
4274 Read the traced branches for the current thread. The remote stub
4275 reports support for this packet to gdb's qSupported query.
4277 *** Changes in GDB 7.5
4279 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
4280 for more x32 ABI info.
4282 * GDB now supports access to MIPS DSP registers on Linux targets.
4284 * GDB now supports debugging microMIPS binaries.
4286 * The "info os" command on GNU/Linux can now display information on
4287 several new classes of objects managed by the operating system:
4288 "info os procgroups" lists process groups
4289 "info os files" lists file descriptors
4290 "info os sockets" lists internet-domain sockets
4291 "info os shm" lists shared-memory regions
4292 "info os semaphores" lists semaphores
4293 "info os msg" lists message queues
4294 "info os modules" lists loaded kernel modules
4296 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
4297 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
4298 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4299 options and inspect the probe arguments using the new $_probe_arg family
4300 of convenience variables. You can obtain more information about SystemTap
4301 in <http://sourceware.org/systemtap/>.
4303 * GDB now supports reversible debugging on ARM, it allows you to
4304 debug basic ARM and THUMB instructions, and provides
4305 record/replay support.
4307 * The option "symbol-reloading" has been deleted as it is no longer used.
4311 ** GDB commands implemented in Python can now be put in command class
4314 ** The "maint set python print-stack on|off" is now deleted.
4316 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4317 apply "flag enum"-style pretty-printing to any enum.
4319 ** gdb.lookup_symbol can now work when there is no current frame.
4321 ** gdb.Symbol now has a 'line' attribute, holding the line number in
4322 the source at which the symbol was defined.
4324 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4325 method 'value'. The former indicates whether the symbol needs a
4326 frame in order to compute its value, and the latter computes the
4329 ** A new method 'referenced_value' on gdb.Value objects which can
4330 dereference pointer as well as C++ reference values.
4332 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4333 which return the global and static blocks (as gdb.Block objects),
4334 of the underlying symbol table, respectively.
4336 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4337 object associated with a PC value.
4339 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4340 of the address range occupied by code for the current source line.
4342 * Go language support.
4343 GDB now supports debugging programs written in the Go programming
4346 * GDBserver now supports stdio connections.
4347 E.g. (gdb) target remote | ssh myhost gdbserver - hello
4349 * The binary "gdbtui" can no longer be built or installed.
4350 Use "gdb -tui" instead.
4352 * GDB will now print "flag" enums specially. A flag enum is one where
4353 all the enumerator values have no bits in common when pairwise
4354 "and"ed. When printing a value whose type is a flag enum, GDB will
4355 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4356 (gdb) print (enum E) 3
4359 * The filename part of a linespec will now match trailing components
4360 of a source file name. For example, "break gcc/expr.c:1000" will
4361 now set a breakpoint in build/gcc/expr.c, but not
4362 build/libcpp/expr.c.
4364 * The "info proc" and "generate-core-file" commands will now also
4365 work on remote targets connected to GDBserver on Linux.
4367 * The command "info catch" has been removed. It has been disabled
4368 since December 2007.
4370 * The "catch exception" and "catch assert" commands now accept
4371 a condition at the end of the command, much like the "break"
4372 command does. For instance:
4374 (gdb) catch exception Constraint_Error if Barrier = True
4376 Previously, it was possible to add a condition to such catchpoints,
4377 but it had to be done as a second step, after the catchpoint had been
4378 created, using the "condition" command.
4380 * The "info static-tracepoint-marker" command will now also work on
4381 native Linux targets with in-process agent.
4383 * GDB can now set breakpoints on inlined functions.
4385 * The .gdb_index section has been updated to include symbols for
4386 inlined functions. GDB will ignore older .gdb_index sections by
4387 default, which could cause symbol files to be loaded more slowly
4388 until their .gdb_index sections can be recreated. The new command
4389 "set use-deprecated-index-sections on" will cause GDB to use any older
4390 .gdb_index sections it finds. This will restore performance, but the
4391 ability to set breakpoints on inlined functions will be lost in symbol
4392 files with older .gdb_index sections.
4394 The .gdb_index section has also been updated to record more information
4395 about each symbol. This speeds up the "info variables", "info functions"
4396 and "info types" commands when used with programs having the .gdb_index
4397 section, as well as speeding up debugging with shared libraries using
4398 the .gdb_index section.
4400 * Ada support for GDB/MI Variable Objects has been added.
4402 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4407 ** New command -info-os is the MI equivalent of "info os".
4409 ** Output logs ("set logging" and related) now include MI output.
4413 ** "set use-deprecated-index-sections on|off"
4414 "show use-deprecated-index-sections on|off"
4415 Controls the use of deprecated .gdb_index sections.
4417 ** "catch load" and "catch unload" can be used to stop when a shared
4418 library is loaded or unloaded, respectively.
4420 ** "enable count" can be used to auto-disable a breakpoint after
4423 ** "info vtbl" can be used to show the virtual method tables for
4424 C++ and Java objects.
4426 ** "explore" and its sub commands "explore value" and "explore type"
4427 can be used to recursively explore values and types of
4428 expressions. These commands are available only if GDB is
4429 configured with '--with-python'.
4431 ** "info auto-load" shows status of all kinds of auto-loaded files,
4432 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4433 sequences of commands files, "info auto-load python-scripts"
4434 shows status of auto-loading Python script files,
4435 "info auto-load local-gdbinit" shows status of loading init file
4436 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4437 status of inferior specific thread debugging shared library loading.
4439 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4440 and "show auto-load-scripts" commands have been deprecated, use their
4441 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4442 and "show auto-load python-scripts" counterparts instead.
4444 ** "dprintf location,format,args..." creates a dynamic printf, which
4445 is basically a breakpoint that does a printf and immediately
4446 resumes your program's execution, so it is like a printf that you
4447 can insert dynamically at runtime instead of at compiletime.
4449 ** "set print symbol"
4451 Controls whether GDB attempts to display the symbol, if any,
4452 corresponding to addresses it prints. This defaults to "on", but
4453 you can set it to "off" to restore GDB's previous behavior.
4455 * Deprecated commands
4457 ** For the Renesas Super-H architecture, the "regs" command has been
4458 deprecated, and "info all-registers" should be used instead.
4462 Renesas RL78 rl78-*-elf
4463 HP OpenVMS ia64 ia64-hp-openvms*
4465 * GDBserver supports evaluation of breakpoint conditions. When
4466 support is advertised by GDBserver, GDB may be told to send the
4467 breakpoint conditions in bytecode form to GDBserver. GDBserver
4468 will only report the breakpoint trigger to GDB when its condition
4473 set mips compression
4474 show mips compression
4475 Select the compressed ISA encoding used in functions that have no symbol
4476 information available. The encoding can be set to either of:
4479 and is updated automatically from ELF file flags if available.
4481 set breakpoint condition-evaluation
4482 show breakpoint condition-evaluation
4483 Control whether breakpoint conditions are evaluated by GDB ("host") or by
4484 GDBserver ("target"). Default option "auto" chooses the most efficient
4486 This option can improve debugger efficiency depending on the speed of the
4490 Disable auto-loading globally.
4493 Show auto-loading setting of all kinds of auto-loaded files.
4495 set auto-load gdb-scripts on|off
4496 show auto-load gdb-scripts
4497 Control auto-loading of GDB canned sequences of commands files.
4499 set auto-load python-scripts on|off
4500 show auto-load python-scripts
4501 Control auto-loading of Python script files.
4503 set auto-load local-gdbinit on|off
4504 show auto-load local-gdbinit
4505 Control loading of init file (.gdbinit) from current directory.
4507 set auto-load libthread-db on|off
4508 show auto-load libthread-db
4509 Control auto-loading of inferior specific thread debugging shared library.
4511 set auto-load scripts-directory <dir1>[:<dir2>...]
4512 show auto-load scripts-directory
4513 Set a list of directories from which to load auto-loaded scripts.
4514 Automatically loaded Python scripts and GDB scripts are located in one
4515 of the directories listed by this option.
4516 The delimiter (':' above) may differ according to the host platform.
4518 set auto-load safe-path <dir1>[:<dir2>...]
4519 show auto-load safe-path
4520 Set a list of directories from which it is safe to auto-load files.
4521 The delimiter (':' above) may differ according to the host platform.
4523 set debug auto-load on|off
4524 show debug auto-load
4525 Control display of debugging info for auto-loading the files above.
4527 set dprintf-style gdb|call|agent
4529 Control the way in which a dynamic printf is performed; "gdb"
4530 requests a GDB printf command, while "call" causes dprintf to call a
4531 function in the inferior. "agent" requests that the target agent
4532 (such as GDBserver) do the printing.
4534 set dprintf-function <expr>
4535 show dprintf-function
4536 set dprintf-channel <expr>
4537 show dprintf-channel
4538 Set the function and optional first argument to the call when using
4539 the "call" style of dynamic printf.
4541 set disconnected-dprintf on|off
4542 show disconnected-dprintf
4543 Control whether agent-style dynamic printfs continue to be in effect
4544 after GDB disconnects.
4546 * New configure options
4548 --with-auto-load-dir
4549 Configure default value for the 'set auto-load scripts-directory'
4550 setting above. It defaults to '$debugdir:$datadir/auto-load',
4551 $debugdir representing global debugging info directories (available
4552 via 'show debug-file-directory') and $datadir representing GDB's data
4553 directory (available via 'show data-directory').
4555 --with-auto-load-safe-path
4556 Configure default value for the 'set auto-load safe-path' setting
4557 above. It defaults to the --with-auto-load-dir setting.
4559 --without-auto-load-safe-path
4560 Set 'set auto-load safe-path' to '/', effectively disabling this
4563 * New remote packets
4565 z0/z1 conditional breakpoints extension
4567 The z0/z1 breakpoint insertion packets have been extended to carry
4568 a list of conditional expressions over to the remote stub depending on the
4569 condition evaluation mode. The use of this extension can be controlled
4570 via the "set remote conditional-breakpoints-packet" command.
4574 Specify the signals which the remote stub may pass to the debugged
4575 program without GDB involvement.
4577 * New command line options
4579 --init-command=FILE, -ix Like --command, -x but execute it
4580 before loading inferior.
4581 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4582 execute it before loading inferior.
4584 *** Changes in GDB 7.4
4586 * GDB now handles ambiguous linespecs more consistently; the existing
4587 FILE:LINE support has been expanded to other types of linespecs. A
4588 breakpoint will now be set on all matching locations in all
4589 inferiors, and locations will be added or removed according to
4592 * GDB now allows you to skip uninteresting functions and files when
4593 stepping with the "skip function" and "skip file" commands.
4595 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4596 and "show remote hardware-watchpoint-length-limit". These allows to
4597 set or show the maximum length limit (in bytes) of a remote
4598 target hardware watchpoint.
4600 This allows e.g. to use "unlimited" hardware watchpoints with the
4601 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
4602 watchpoints are slower than real hardware watchpoints but are
4603 significantly faster than gdb software watchpoints.
4607 ** The register_pretty_printer function in module gdb.printing now takes
4608 an optional `replace' argument. If True, the new printer replaces any
4611 ** The "maint set python print-stack on|off" command has been
4612 deprecated and will be deleted in GDB 7.5.
4613 A new command: "set python print-stack none|full|message" has
4614 replaced it. Additionally, the default for "print-stack" is
4615 now "message", which just prints the error message without
4618 ** A prompt substitution hook (prompt_hook) is now available to the
4621 ** A new Python module, gdb.prompt has been added to the GDB Python
4622 modules library. This module provides functionality for
4623 escape sequences in prompts (used by set/show
4624 extended-prompt). These escape sequences are replaced by their
4625 corresponding value.
4627 ** Python commands and convenience-functions located in
4628 'data-directory'/python/gdb/command and
4629 'data-directory'/python/gdb/function are now automatically loaded
4632 ** Blocks now provide four new attributes. global_block and
4633 static_block will return the global and static blocks
4634 respectively. is_static and is_global are boolean attributes
4635 that indicate if the block is one of those two types.
4637 ** Symbols now provide the "type" attribute, the type of the symbol.
4639 ** The "gdb.breakpoint" function has been deprecated in favor of
4642 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4643 of a function. This class is based on the "finish" command
4644 available in the CLI.
4646 ** Type objects for struct and union types now allow access to
4647 the fields using standard Python dictionary (mapping) methods.
4648 For example, "some_type['myfield']" now works, as does
4649 "some_type.items()".
4651 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4654 ** A new function, "deep_items" has been added to the gdb.types
4655 module in the GDB Python modules library. This function returns
4656 an iterator over the fields of a struct or union type. Unlike
4657 the standard Python "iteritems" method, it will recursively traverse
4658 any anonymous fields.
4662 ** "*stopped" events can report several new "reason"s, such as
4665 ** Breakpoint changes are now notified using new async records, like
4666 "=breakpoint-modified".
4668 ** New command -ada-task-info.
4670 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4671 $sdir specifies the default system locations of shared libraries.
4672 $pdir specifies the directory where the libpthread used by the application
4675 GDB no longer looks in $sdir and $pdir after it has searched the directories
4676 mentioned in libthread-db-search-path. If you want to search those
4677 directories, they must be specified in libthread-db-search-path.
4678 The default value of libthread-db-search-path on GNU/Linux and Solaris
4679 systems is now "$sdir:$pdir".
4681 $pdir is not supported by gdbserver, it is currently ignored.
4682 $sdir is supported by gdbserver.
4684 * New configure option --with-iconv-bin.
4685 When using the internationalization support like the one in the GNU C
4686 library, GDB will invoke the "iconv" program to get a list of supported
4687 character sets. If this program lives in a non-standard location, one can
4688 use this option to specify where to find it.
4690 * When natively debugging programs on PowerPC BookE processors running
4691 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4692 watchpoints, which specify a mask in addition to an address to watch.
4693 The mask specifies that some bits of an address (the bits which are
4694 reset in the mask) should be ignored when matching the address accessed
4695 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4696 section in the user manual for more details.
4698 * The new option --once causes GDBserver to stop listening for connections once
4699 the first connection is made. The listening port used by GDBserver will
4700 become available after that.
4702 * New commands "info macros" and "alias" have been added.
4704 * New function parameters suffix @entry specifies value of function parameter
4705 at the time the function got called. Entry values are available only since
4711 "!" is now an alias of the "shell" command.
4712 Note that no space is needed between "!" and SHELL COMMAND.
4716 watch EXPRESSION mask MASK_VALUE
4717 The watch command now supports the mask argument which allows creation
4718 of masked watchpoints, if the current architecture supports this feature.
4720 info auto-load-scripts [REGEXP]
4721 This command was formerly named "maintenance print section-scripts".
4722 It is now generally useful and is no longer a maintenance-only command.
4724 info macro [-all] [--] MACRO
4725 The info macro command has new options `-all' and `--'. The first for
4726 printing all definitions of a macro. The second for explicitly specifying
4727 the end of arguments and the beginning of the macro name in case the macro
4728 name starts with a hyphen.
4730 collect[/s] EXPRESSIONS
4731 The tracepoint collect command now takes an optional modifier "/s"
4732 that directs it to dereference pointer-to-character types and
4733 collect the bytes of memory up to a zero byte. The behavior is
4734 similar to what you see when you use the regular print command on a
4735 string. An optional integer following the "/s" sets a bound on the
4736 number of bytes that will be collected.
4739 The trace start command now interprets any supplied arguments as a
4740 note to be recorded with the trace run, with an effect similar to
4741 setting the variable trace-notes.
4744 The trace stop command now interprets any arguments as a note to be
4745 mentioned along with the tstatus report that the trace was stopped
4746 with a command. The effect is similar to setting the variable
4749 * Tracepoints can now be enabled and disabled at any time after a trace
4750 experiment has been started using the standard "enable" and "disable"
4751 commands. It is now possible to start a trace experiment with no enabled
4752 tracepoints; GDB will display a warning, but will allow the experiment to
4753 begin, assuming that tracepoints will be enabled as needed while the trace
4756 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4757 locations with 4-byte instructions, when they were previously
4758 limited to locations with instructions of 5 bytes or longer.
4762 set debug dwarf2-read
4763 show debug dwarf2-read
4764 Turns on or off display of debugging messages related to reading
4765 DWARF debug info. The default is off.
4767 set debug symtab-create
4768 show debug symtab-create
4769 Turns on or off display of debugging messages related to symbol table
4770 creation. The default is off.
4773 show extended-prompt
4774 Set the GDB prompt, and allow escape sequences to be inserted to
4775 display miscellaneous information (see 'help set extended-prompt'
4776 for the list of sequences). This prompt (and any information
4777 accessed through the escape sequences) is updated every time the
4778 prompt is displayed.
4780 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4781 show print entry-values
4782 Set printing of frame argument values at function entry. In some cases
4783 GDB can determine the value of function argument which was passed by the
4784 function caller, even if the value was modified inside the called function.
4786 set debug entry-values
4787 show debug entry-values
4788 Control display of debugging info for determining frame argument values at
4789 function entry and virtual tail call frames.
4791 set basenames-may-differ
4792 show basenames-may-differ
4793 Set whether a source file may have multiple base names.
4794 (A "base name" is the name of a file with the directory part removed.
4795 Example: The base name of "/home/user/hello.c" is "hello.c".)
4796 If set, GDB will canonicalize file names (e.g., expand symlinks)
4797 before comparing them. Canonicalization is an expensive operation,
4798 but it allows the same file be known by more than one base name.
4799 If not set (the default), all source files are assumed to have just
4800 one base name, and gdb will do file name comparisons more efficiently.
4806 Set a user name and notes for the current and any future trace runs.
4807 This is useful for long-running and/or disconnected traces, to
4808 inform others (or yourself) as to who is running the trace, supply
4809 contact information, or otherwise explain what is going on.
4811 set trace-stop-notes
4812 show trace-stop-notes
4813 Set a note attached to the trace run, that is displayed when the
4814 trace has been stopped by a tstop command. This is useful for
4815 instance as an explanation, if you are stopping a trace run that was
4816 started by someone else.
4818 * New remote packets
4822 Dynamically enable a tracepoint in a started trace experiment.
4826 Dynamically disable a tracepoint in a started trace experiment.
4830 Set the user and notes of the trace run.
4834 Query the current status of a tracepoint.
4838 Query the minimum length of instruction at which a fast tracepoint may
4841 * Dcache size (number of lines) and line-size are now runtime-configurable
4842 via "set dcache line" and "set dcache line-size" commands.
4846 Texas Instruments TMS320C6x tic6x-*-*
4850 Renesas RL78 rl78-*-elf
4852 *** Changes in GDB 7.3.1
4854 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4856 *** Changes in GDB 7.3
4858 * GDB has a new command: "thread find [REGEXP]".
4859 It finds the thread id whose name, target id, or thread extra info
4860 matches the given regular expression.
4862 * The "catch syscall" command now works on mips*-linux* targets.
4864 * The -data-disassemble MI command now supports modes 2 and 3 for
4865 dumping the instruction opcodes.
4867 * New command line options
4869 -data-directory DIR Specify DIR as the "data-directory".
4870 This is mostly for testing purposes.
4872 * The "maint set python auto-load on|off" command has been renamed to
4873 "set auto-load-scripts on|off".
4875 * GDB has a new command: "set directories".
4876 It is like the "dir" command except that it replaces the
4877 source path list instead of augmenting it.
4879 * GDB now understands thread names.
4881 On GNU/Linux, "info threads" will display the thread name as set by
4882 prctl or pthread_setname_np.
4884 There is also a new command, "thread name", which can be used to
4885 assign a name internally for GDB to display.
4888 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4889 has been integrated into GDB.
4893 ** The function gdb.Write now accepts an optional keyword 'stream'.
4894 This keyword, when provided, will direct the output to either
4895 stdout, stderr, or GDB's logging output.
4897 ** Parameters can now be be sub-classed in Python, and in particular
4898 you may implement the get_set_doc and get_show_doc functions.
4899 This improves how Parameter set/show documentation is processed
4900 and allows for more dynamic content.
4902 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4903 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4904 have an is_valid method.
4906 ** Breakpoints can now be sub-classed in Python, and in particular
4907 you may implement a 'stop' function that is executed each time
4908 the inferior reaches that breakpoint.
4910 ** New function gdb.lookup_global_symbol looks up a global symbol.
4912 ** GDB values in Python are now callable if the value represents a
4913 function. For example, if 'some_value' represents a function that
4914 takes two integer parameters and returns a value, you can call
4915 that function like so:
4917 result = some_value (10,20)
4919 ** Module gdb.types has been added.
4920 It contains a collection of utilities for working with gdb.Types objects:
4921 get_basic_type, has_field, make_enum_dict.
4923 ** Module gdb.printing has been added.
4924 It contains utilities for writing and registering pretty-printers.
4925 New classes: PrettyPrinter, SubPrettyPrinter,
4926 RegexpCollectionPrettyPrinter.
4927 New function: register_pretty_printer.
4929 ** New commands "info pretty-printers", "enable pretty-printer" and
4930 "disable pretty-printer" have been added.
4932 ** gdb.parameter("directories") is now available.
4934 ** New function gdb.newest_frame returns the newest frame in the
4937 ** The gdb.InferiorThread class has a new "name" attribute. This
4938 holds the thread's name.
4940 ** Python Support for Inferior events.
4941 Python scripts can add observers to be notified of events
4942 occurring in the process being debugged.
4943 The following events are currently supported:
4944 - gdb.events.cont Continue event.
4945 - gdb.events.exited Inferior exited event.
4946 - gdb.events.stop Signal received, and Breakpoint hit events.
4950 ** GDB now puts template parameters in scope when debugging in an
4951 instantiation. For example, if you have:
4953 template<int X> int func (void) { return X; }
4955 then if you step into func<5>, "print X" will show "5". This
4956 feature requires proper debuginfo support from the compiler; it
4957 was added to GCC 4.5.
4959 ** The motion commands "next", "finish", "until", and "advance" now
4960 work better when exceptions are thrown. In particular, GDB will
4961 no longer lose control of the inferior; instead, the GDB will
4962 stop the inferior at the point at which the exception is caught.
4963 This functionality requires a change in the exception handling
4964 code that was introduced in GCC 4.5.
4966 * GDB now follows GCC's rules on accessing volatile objects when
4967 reading or writing target state during expression evaluation.
4968 One notable difference to prior behavior is that "print x = 0"
4969 no longer generates a read of x; the value of the assignment is
4970 now always taken directly from the value being assigned.
4972 * GDB now has some support for using labels in the program's source in
4973 linespecs. For instance, you can use "advance label" to continue
4974 execution to a label.
4976 * GDB now has support for reading and writing a new .gdb_index
4977 section. This section holds a fast index of DWARF debugging
4978 information and can be used to greatly speed up GDB startup and
4979 operation. See the documentation for `save gdb-index' for details.
4981 * The "watch" command now accepts an optional "-location" argument.
4982 When used, this causes GDB to watch the memory referred to by the
4983 expression. Such a watchpoint is never deleted due to it going out
4986 * GDB now supports thread debugging of core dumps on GNU/Linux.
4988 GDB now activates thread debugging using the libthread_db library
4989 when debugging GNU/Linux core dumps, similarly to when debugging
4990 live processes. As a result, when debugging a core dump file, GDB
4991 is now able to display pthread_t ids of threads. For example, "info
4992 threads" shows the same output as when debugging the process when it
4993 was live. In earlier releases, you'd see something like this:
4996 * 1 LWP 6780 main () at main.c:10
4998 While now you see this:
5001 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
5003 It is also now possible to inspect TLS variables when debugging core
5006 When debugging a core dump generated on a machine other than the one
5007 used to run GDB, you may need to point GDB at the correct
5008 libthread_db library with the "set libthread-db-search-path"
5009 command. See the user manual for more details on this command.
5011 * When natively debugging programs on PowerPC BookE processors running
5012 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
5013 which stop execution of the inferior whenever it executes an instruction
5014 at any address within the specified range. See the "PowerPC Embedded"
5015 section in the user manual for more details.
5017 * New features in the GDB remote stub, GDBserver
5019 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
5020 and i686 LynxOS (version 5.x).
5022 ** GDBserver is now supported on Blackfin Linux.
5024 * New native configurations
5026 ia64 HP-UX ia64-*-hpux*
5030 Analog Devices, Inc. Blackfin Processor bfin-*
5032 * Ada task switching is now supported on sparc-elf targets when
5033 debugging a program using the Ravenscar Profile. For more information,
5034 see the "Tasking Support when using the Ravenscar Profile" section
5035 in the GDB user manual.
5037 * Guile support was removed.
5039 * New features in the GNU simulator
5041 ** The --map-info flag lists all known core mappings.
5043 ** CFI flashes may be simulated via the "cfi" device.
5045 *** Changes in GDB 7.2
5047 * Shared library support for remote targets by default
5049 When GDB is configured for a generic, non-OS specific target, like
5050 for example, --target=arm-eabi or one of the many *-*-elf targets,
5051 GDB now queries remote stubs for loaded shared libraries using the
5052 `qXfer:libraries:read' packet. Previously, shared library support
5053 was always disabled for such configurations.
5057 ** Argument Dependent Lookup (ADL)
5059 In C++ ADL lookup directs function search to the namespaces of its
5060 arguments even if the namespace has not been imported.
5070 Here the compiler will search for `foo' in the namespace of 'b'
5071 and find A::foo. GDB now supports this. This construct is commonly
5072 used in the Standard Template Library for operators.
5074 ** Improved User Defined Operator Support
5076 In addition to member operators, GDB now supports lookup of operators
5077 defined in a namespace and imported with a `using' directive, operators
5078 defined in the global scope, operators imported implicitly from an
5079 anonymous namespace, and the ADL operators mentioned in the previous
5081 GDB now also supports proper overload resolution for all the previously
5082 mentioned flavors of operators.
5084 ** static const class members
5086 Printing of static const class members that are initialized in the
5087 class definition has been fixed.
5089 * Windows Thread Information Block access.
5091 On Windows targets, GDB now supports displaying the Windows Thread
5092 Information Block (TIB) structure. This structure is visible either
5093 by using the new command `info w32 thread-information-block' or, by
5094 dereferencing the new convenience variable named `$_tlb', a
5095 thread-specific pointer to the TIB. This feature is also supported
5096 when remote debugging using GDBserver.
5098 * Static tracepoints
5100 Static tracepoints are calls in the user program into a tracing
5101 library. One such library is a port of the LTTng kernel tracer to
5102 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
5103 When debugging with GDBserver, GDB now supports combining the GDB
5104 tracepoint machinery with such libraries. For example: the user can
5105 use GDB to probe a static tracepoint marker (a call from the user
5106 program into the tracing library) with the new "strace" command (see
5107 "New commands" below). This creates a "static tracepoint" in the
5108 breakpoint list, that can be manipulated with the same feature set
5109 as fast and regular tracepoints. E.g., collect registers, local and
5110 global variables, collect trace state variables, and define
5111 tracepoint conditions. In addition, the user can collect extra
5112 static tracepoint marker specific data, by collecting the new
5113 $_sdata internal variable. When analyzing the trace buffer, you can
5114 inspect $_sdata like any other variable available to GDB. For more
5115 information, see the "Tracepoints" chapter in GDB user manual. New
5116 remote packets have been defined to support static tracepoints, see
5117 the "New remote packets" section below.
5119 * Better reconstruction of tracepoints after disconnected tracing
5121 GDB will attempt to download the original source form of tracepoint
5122 definitions when starting a trace run, and then will upload these
5123 upon reconnection to the target, resulting in a more accurate
5124 reconstruction of the tracepoints that are in use on the target.
5128 You can now exercise direct control over the ways that GDB can
5129 affect your program. For instance, you can disallow the setting of
5130 breakpoints, so that the program can run continuously (assuming
5131 non-stop mode). In addition, the "observer" variable is available
5132 to switch all of the different controls; in observer mode, GDB
5133 cannot affect the target's behavior at all, which is useful for
5134 tasks like diagnosing live systems in the field.
5136 * The new convenience variable $_thread holds the number of the
5139 * New remote packets
5143 Return the address of the Windows Thread Information Block of a given thread.
5147 In response to several of the tracepoint packets, the target may now
5148 also respond with a number of intermediate `qRelocInsn' request
5149 packets before the final result packet, to have GDB handle
5150 relocating an instruction to execute at a different address. This
5151 is particularly useful for stubs that support fast tracepoints. GDB
5152 reports support for this feature in the qSupported packet.
5156 List static tracepoint markers in the target program.
5160 List static tracepoint markers at a given address in the target
5163 qXfer:statictrace:read
5165 Read the static trace data collected (by a `collect $_sdata'
5166 tracepoint action). The remote stub reports support for this packet
5167 to gdb's qSupported query.
5171 Send the current settings of GDB's permission flags.
5175 Send part of the source (textual) form of a tracepoint definition,
5176 which includes location, conditional, and action list.
5178 * The source command now accepts a -s option to force searching for the
5179 script in the source search path even if the script name specifies
5182 * New features in the GDB remote stub, GDBserver
5184 - GDBserver now support tracepoints (including fast tracepoints, and
5185 static tracepoints). The feature is currently supported by the
5186 i386-linux and amd64-linux builds. See the "Tracepoints support
5187 in gdbserver" section in the manual for more information.
5189 GDBserver JIT compiles the tracepoint's conditional agent
5190 expression bytecode into native code whenever possible for low
5191 overhead dynamic tracepoints conditionals. For such tracepoints,
5192 an expression that examines program state is evaluated when the
5193 tracepoint is reached, in order to determine whether to capture
5194 trace data. If the condition is simple and false, processing the
5195 tracepoint finishes very quickly and no data is gathered.
5197 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
5198 for static tracepoints support.
5200 - GDBserver now supports x86_64 Windows 64-bit debugging.
5202 * GDB now sends xmlRegisters= in qSupported packet to indicate that
5203 it understands register description.
5205 * The --batch flag now disables pagination and queries.
5207 * X86 general purpose registers
5209 GDB now supports reading/writing byte, word and double-word x86
5210 general purpose registers directly. This means you can use, say,
5211 $ah or $ax to refer, respectively, to the byte register AH and
5212 16-bit word register AX that are actually portions of the 32-bit
5213 register EAX or 64-bit register RAX.
5215 * The `commands' command now accepts a range of breakpoints to modify.
5216 A plain `commands' following a command that creates multiple
5217 breakpoints affects all the breakpoints set by that command. This
5218 applies to breakpoints set by `rbreak', and also applies when a
5219 single `break' command creates multiple breakpoints (e.g.,
5220 breakpoints on overloaded c++ functions).
5222 * The `rbreak' command now accepts a filename specification as part of
5223 its argument, limiting the functions selected by the regex to those
5224 in the specified file.
5226 * Support for remote debugging Windows and SymbianOS shared libraries
5227 from Unix hosts has been improved. Non Windows GDB builds now can
5228 understand target reported file names that follow MS-DOS based file
5229 system semantics, such as file names that include drive letters and
5230 use the backslash character as directory separator. This makes it
5231 possible to transparently use the "set sysroot" and "set
5232 solib-search-path" on Unix hosts to point as host copies of the
5233 target's shared libraries. See the new command "set
5234 target-file-system-kind" described below, and the "Commands to
5235 specify files" section in the user manual for more information.
5239 eval template, expressions...
5240 Convert the values of one or more expressions under the control
5241 of the string template to a command line, and call it.
5243 set target-file-system-kind unix|dos-based|auto
5244 show target-file-system-kind
5245 Set or show the assumed file system kind for target reported file
5248 save breakpoints <filename>
5249 Save all current breakpoint definitions to a file suitable for use
5250 in a later debugging session. To read the saved breakpoint
5251 definitions, use the `source' command.
5253 `save tracepoints' is a new alias for `save-tracepoints'. The latter
5256 info static-tracepoint-markers
5257 Display information about static tracepoint markers in the target.
5259 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5260 Define a static tracepoint by probing a marker at the given
5261 function, line, address, or marker ID.
5265 Enable and disable observer mode.
5267 set may-write-registers on|off
5268 set may-write-memory on|off
5269 set may-insert-breakpoints on|off
5270 set may-insert-tracepoints on|off
5271 set may-insert-fast-tracepoints on|off
5272 set may-interrupt on|off
5273 Set individual permissions for GDB effects on the target. Note that
5274 some of these settings can have undesirable or surprising
5275 consequences, particularly when changed in the middle of a session.
5276 For instance, disabling the writing of memory can prevent
5277 breakpoints from being inserted, cause single-stepping to fail, or
5278 even crash your program, if you disable after breakpoints have been
5279 inserted. However, GDB should not crash.
5281 set record memory-query on|off
5282 show record memory-query
5283 Control whether to stop the inferior if memory changes caused
5284 by an instruction cannot be recorded.
5289 The disassemble command now supports "start,+length" form of two arguments.
5293 ** GDB now provides a new directory location, called the python directory,
5294 where Python scripts written for GDB can be installed. The location
5295 of that directory is <data-directory>/python, where <data-directory>
5296 is the GDB data directory. For more details, see section `Scripting
5297 GDB using Python' in the manual.
5299 ** The GDB Python API now has access to breakpoints, symbols, symbol
5300 tables, program spaces, inferiors, threads and frame's code blocks.
5301 Additionally, GDB Parameters can now be created from the API, and
5302 manipulated via set/show in the CLI.
5304 ** New functions gdb.target_charset, gdb.target_wide_charset,
5305 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5307 ** New exception gdb.GdbError.
5309 ** Pretty-printers are now also looked up in the current program space.
5311 ** Pretty-printers can now be individually enabled and disabled.
5313 ** GDB now looks for names of Python scripts to auto-load in a
5314 special section named `.debug_gdb_scripts', in addition to looking
5315 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5317 * Tracepoint actions were unified with breakpoint commands. In particular,
5318 there are no longer differences in "info break" output for breakpoints and
5319 tracepoints and the "commands" command can be used for both tracepoints and
5320 regular breakpoints.
5324 ARM Symbian arm*-*-symbianelf*
5326 * D language support.
5327 GDB now supports debugging programs written in the D programming
5330 * GDB now supports the extended ptrace interface for PowerPC which is
5331 available since Linux kernel version 2.6.34. This automatically enables
5332 any hardware breakpoints and additional hardware watchpoints available in
5333 the processor. The old ptrace interface exposes just one hardware
5334 watchpoint and no hardware breakpoints.
5336 * GDB is now able to use the Data Value Compare (DVC) register available on
5337 embedded PowerPC processors to implement in hardware simple watchpoint
5338 conditions of the form:
5340 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5342 This works in native GDB running on Linux kernels with the extended ptrace
5343 interface mentioned above.
5345 *** Changes in GDB 7.1
5349 ** Namespace Support
5351 GDB now supports importing of namespaces in C++. This enables the
5352 user to inspect variables from imported namespaces. Support for
5353 namepace aliasing has also been added. So, if a namespace is
5354 aliased in the current scope (e.g. namepace C=A; ) the user can
5355 print variables using the alias (e.g. (gdb) print C::x).
5359 All known bugs relating to the printing of virtual base class were
5360 fixed. It is now possible to call overloaded static methods using a
5365 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5366 and reinterpret_cast<> are now handled by the C++ expression parser.
5370 Xilinx MicroBlaze microblaze-*-*
5375 Xilinx MicroBlaze microblaze
5378 * Multi-program debugging.
5380 GDB now has support for multi-program (a.k.a. multi-executable or
5381 multi-exec) debugging. This allows for debugging multiple inferiors
5382 simultaneously each running a different program under the same GDB
5383 session. See "Debugging Multiple Inferiors and Programs" in the
5384 manual for more information. This implied some user visible changes
5385 in the multi-inferior support. For example, "info inferiors" now
5386 lists inferiors that are not running yet or that have exited
5387 already. See also "New commands" and "New options" below.
5389 * New tracing features
5391 GDB's tracepoint facility now includes several new features:
5393 ** Trace state variables
5395 GDB tracepoints now include support for trace state variables, which
5396 are variables managed by the target agent during a tracing
5397 experiment. They are useful for tracepoints that trigger each
5398 other, so for instance one tracepoint can count hits in a variable,
5399 and then a second tracepoint has a condition that is true when the
5400 count reaches a particular value. Trace state variables share the
5401 $-syntax of GDB convenience variables, and can appear in both
5402 tracepoint actions and condition expressions. Use the "tvariable"
5403 command to create, and "info tvariables" to view; see "Trace State
5404 Variables" in the manual for more detail.
5408 GDB now includes an option for defining fast tracepoints, which
5409 targets may implement more efficiently, such as by installing a jump
5410 into the target agent rather than a trap instruction. The resulting
5411 speedup can be by two orders of magnitude or more, although the
5412 tradeoff is that some program locations on some target architectures
5413 might not allow fast tracepoint installation, for instance if the
5414 instruction to be replaced is shorter than the jump. To request a
5415 fast tracepoint, use the "ftrace" command, with syntax identical to
5416 the regular trace command.
5418 ** Disconnected tracing
5420 It is now possible to detach GDB from the target while it is running
5421 a trace experiment, then reconnect later to see how the experiment
5422 is going. In addition, a new variable disconnected-tracing lets you
5423 tell the target agent whether to continue running a trace if the
5424 connection is lost unexpectedly.
5428 GDB now has the ability to save the trace buffer into a file, and
5429 then use that file as a target, similarly to you can do with
5430 corefiles. You can select trace frames, print data that was
5431 collected in them, and use tstatus to display the state of the
5432 tracing run at the moment that it was saved. To create a trace
5433 file, use "tsave <filename>", and to use it, do "target tfile
5436 ** Circular trace buffer
5438 You can ask the target agent to handle the trace buffer as a
5439 circular buffer, discarding the oldest trace frames to make room for
5440 newer ones, by setting circular-trace-buffer to on. This feature may
5441 not be available for all target agents.
5446 The disassemble command, when invoked with two arguments, now requires
5447 the arguments to be comma-separated.
5450 The info variables command now displays variable definitions. Files
5451 which only declare a variable are not shown.
5454 The source command is now capable of sourcing Python scripts.
5455 This feature is dependent on the debugger being build with Python
5458 Related to this enhancement is also the introduction of a new command
5459 "set script-extension" (see below).
5461 * New commands (for set/show, see "New options" below)
5463 record save [<FILENAME>]
5464 Save a file (in core file format) containing the process record
5465 execution log for replay debugging at a later time.
5467 record restore <FILENAME>
5468 Restore the process record execution log that was saved at an
5469 earlier time, for replay debugging.
5471 add-inferior [-copies <N>] [-exec <FILENAME>]
5474 clone-inferior [-copies <N>] [ID]
5475 Make a new inferior ready to execute the same program another
5476 inferior has loaded.
5481 maint info program-spaces
5482 List the program spaces loaded into GDB.
5484 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5485 show remote interrupt-sequence
5486 Allow the user to select one of ^C, a BREAK signal or BREAK-g
5487 as the sequence to the remote target in order to interrupt the execution.
5488 Ctrl-C is a default. Some system prefers BREAK which is high level of
5489 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
5490 Magic SysRq g. It is BREAK signal and character 'g'.
5492 set remote interrupt-on-connect [on | off]
5493 show remote interrupt-on-connect
5494 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5495 remote target when gdb connects to it. This is needed when you debug
5498 set remotebreak [on | off]
5500 Deprecated. Use "set/show remote interrupt-sequence" instead.
5502 tvariable $NAME [ = EXP ]
5503 Create or modify a trace state variable.
5506 List trace state variables and their values.
5508 delete tvariable $NAME ...
5509 Delete one or more trace state variables.
5512 Evaluate the given expressions without collecting anything into the
5513 trace buffer. (Valid in tracepoint actions only.)
5515 ftrace FN / FILE:LINE / *ADDR
5516 Define a fast tracepoint at the given function, line, or address.
5518 * New expression syntax
5520 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5521 GDB now parses 0b101010 identically with 42.
5525 set follow-exec-mode new|same
5526 show follow-exec-mode
5527 Control whether GDB reuses the same inferior across an exec call or
5528 creates a new one. This is useful to be able to restart the old
5529 executable after the inferior having done an exec call.
5531 set default-collect EXPR, ...
5532 show default-collect
5533 Define a list of expressions to be collected at each tracepoint.
5534 This is a useful way to ensure essential items are not overlooked,
5535 such as registers or a critical global variable.
5537 set disconnected-tracing
5538 show disconnected-tracing
5539 If set to 1, the target is instructed to continue tracing if it
5540 loses its connection to GDB. If 0, the target is to stop tracing
5543 set circular-trace-buffer
5544 show circular-trace-buffer
5545 If set to on, the target is instructed to use a circular trace buffer
5546 and discard the oldest trace frames instead of stopping the trace due
5547 to a full trace buffer. If set to off, the trace stops when the buffer
5548 fills up. Some targets may not support this.
5550 set script-extension off|soft|strict
5551 show script-extension
5552 If set to "off", the debugger does not perform any script language
5553 recognition, and all sourced files are assumed to be GDB scripts.
5554 If set to "soft" (the default), files are sourced according to
5555 filename extension, falling back to GDB scripts if the first
5557 If set to "strict", files are sourced according to filename extension.
5559 set ada trust-PAD-over-XVS on|off
5560 show ada trust-PAD-over-XVS
5561 If off, activate a workaround against a bug in the debugging information
5562 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5563 the GCC sources for more information about the GNAT encoding and
5564 PAD types in particular). It is always safe to set this option to
5565 off, but this introduces a slight performance penalty. The default
5568 * Python API Improvements
5570 ** GDB provides the new class gdb.LazyString. This is useful in
5571 some pretty-printing cases. The new method gdb.Value.lazy_string
5572 provides a simple way to create objects of this type.
5574 ** The fields returned by gdb.Type.fields now have an
5575 `is_base_class' attribute.
5577 ** The new method gdb.Type.range returns the range of an array type.
5579 ** The new method gdb.parse_and_eval can be used to parse and
5580 evaluate an expression.
5582 * New remote packets
5585 Define a trace state variable.
5588 Get the current value of a trace state variable.
5591 Set desired tracing behavior upon disconnection.
5594 Set the trace buffer to be linear or circular.
5597 Get data about the tracepoints currently in use.
5601 Process record now works correctly with hardware watchpoints.
5603 Multiple bug fixes have been made to the mips-irix port, making it
5604 much more reliable. In particular:
5605 - Debugging threaded applications is now possible again. Previously,
5606 GDB would hang while starting the program, or while waiting for
5607 the program to stop at a breakpoint.
5608 - Attaching to a running process no longer hangs.
5609 - An error occurring while loading a core file has been fixed.
5610 - Changing the value of the PC register now works again. This fixes
5611 problems observed when using the "jump" command, or when calling
5612 a function from GDB, or even when assigning a new value to $pc.
5613 - With the "finish" and "return" commands, the return value for functions
5614 returning a small array is now correctly printed.
5615 - It is now possible to break on shared library code which gets executed
5616 during a shared library init phase (code executed while executing
5617 their .init section). Previously, the breakpoint would have no effect.
5618 - GDB is now able to backtrace through the signal handler for
5619 non-threaded programs.
5621 PIE (Position Independent Executable) programs debugging is now supported.
5622 This includes debugging execution of PIC (Position Independent Code) shared
5623 libraries although for that, it should be possible to run such libraries as an
5626 *** Changes in GDB 7.0
5628 * GDB now has an interface for JIT compilation. Applications that
5629 dynamically generate code can create symbol files in memory and register
5630 them with GDB. For users, the feature should work transparently, and
5631 for JIT developers, the interface is documented in the GDB manual in the
5632 "JIT Compilation Interface" chapter.
5634 * Tracepoints may now be conditional. The syntax is as for
5635 breakpoints; either an "if" clause appended to the "trace" command,
5636 or the "condition" command is available. GDB sends the condition to
5637 the target for evaluation using the same bytecode format as is used
5638 for tracepoint actions.
5640 * The disassemble command now supports: an optional /r modifier, print the
5641 raw instructions in hex as well as in symbolic form, and an optional /m
5642 modifier to print mixed source+assembly.
5644 * Process record and replay
5646 In a architecture environment that supports ``process record and
5647 replay'', ``process record and replay'' target can record a log of
5648 the process execution, and replay it with both forward and reverse
5651 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5652 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5653 set execution-direction {forward|reverse}, for targets that support
5656 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5657 feature is available with a native GDB running on kernel version
5660 * GDB now has support for multi-byte and wide character sets on the
5661 target. Strings whose character type is wchar_t, char16_t, or
5662 char32_t are now correctly printed. GDB supports wide- and unicode-
5663 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5664 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5665 `printf'. This feature requires iconv to work properly; if your
5666 system does not have a working iconv, GDB can use GNU libiconv. See
5667 the installation instructions for more information.
5669 * GDB now supports automatic retrieval of shared library files from
5670 remote targets. To use this feature, specify a system root that begins
5671 with the `remote:' prefix, either via the `set sysroot' command or via
5672 the `--with-sysroot' configure-time option.
5674 * "info sharedlibrary" now takes an optional regex of libraries to show,
5675 and it now reports if a shared library has no debugging information.
5677 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5678 now complete on file names.
5680 * When completing in expressions, gdb will attempt to limit
5681 completions to allowable structure or union fields, where appropriate.
5682 For instance, consider:
5684 # struct example { int f1; double f2; };
5685 # struct example variable;
5688 If the user types TAB at the end of this command line, the available
5689 completions will be "f1" and "f2".
5691 * Inlined functions are now supported. They show up in backtraces, and
5692 the "step", "next", and "finish" commands handle them automatically.
5694 * GDB now supports the token-splicing (##) and stringification (#)
5695 operators when expanding macros. It also supports variable-arity
5698 * GDB now supports inspecting extra signal information, exported by
5699 the new $_siginfo convenience variable. The feature is currently
5700 implemented on linux ARM, i386 and amd64.
5702 * GDB can now display the VFP floating point registers and NEON vector
5703 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5704 can provide these registers (requires Linux 2.6.30 or later). Remote
5705 and simulator targets may also provide them.
5707 * New remote packets
5710 Search memory for a sequence of bytes.
5713 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5714 operation over reliable transport links. Use of this packet is
5715 controlled by the `set remote noack-packet' command.
5718 Kill the process with the specified process ID. Use this in preference
5719 to `k' when multiprocess protocol extensions are supported.
5722 Obtains additional operating system information
5726 Read or write additional signal information.
5728 * Removed remote protocol undocumented extension
5730 An undocumented extension to the remote protocol's `S' stop reply
5731 packet that permitted the stub to pass a process id was removed.
5732 Remote servers should use the `T' stop reply packet instead.
5734 * GDB now supports multiple function calling conventions according to the
5735 DWARF-2 DW_AT_calling_convention function attribute.
5737 * The SH target utilizes the aforementioned change to distinguish between gcc
5738 and Renesas calling convention. It also adds the new CLI commands
5739 `set/show sh calling-convention'.
5741 * GDB can now read compressed debug sections, as produced by GNU gold
5742 with the --compress-debug-sections=zlib flag.
5744 * 64-bit core files are now supported on AIX.
5746 * Thread switching is now supported on Tru64.
5748 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5749 which will be allocated using malloc later in program execution.
5751 * The qXfer:libraries:read remote protocol packet now allows passing a
5752 list of section offsets.
5754 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5755 conditions handling signals delivered during attach or thread creation
5756 have also been fixed.
5758 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5759 From the user's standpoint, all unqualified instances of True and False
5760 are treated as the standard definitions, regardless of context.
5762 * GDB now parses C++ symbol and type names more flexibly. For
5765 template<typename T> class C { };
5768 GDB will now correctly handle all of:
5770 ptype C<char const *>
5771 ptype C<char const*>
5772 ptype C<const char *>
5773 ptype C<const char*>
5775 * New features in the GDB remote stub, gdbserver
5777 - The "--wrapper" command-line argument tells gdbserver to use a
5778 wrapper program to launch programs for debugging.
5780 - On PowerPC and S/390 targets, it is now possible to use a single
5781 gdbserver executable to debug both 32-bit and 64-bit programs.
5782 (This requires gdbserver itself to be built as a 64-bit executable.)
5784 - gdbserver uses the new noack protocol mode for TCP connections to
5785 reduce communications latency, if also supported and enabled in GDB.
5787 - Support for the sparc64-linux-gnu target is now included in
5790 - The amd64-linux build of gdbserver now supports debugging both
5791 32-bit and 64-bit programs.
5793 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5794 now support hardware watchpoints, and will use them automatically
5799 GDB now has support for scripting using Python. Whether this is
5800 available is determined at configure time.
5802 New GDB commands can now be written in Python.
5804 * Ada tasking support
5806 Ada tasks can now be inspected in GDB. The following commands have
5810 Print the list of Ada tasks.
5812 Print detailed information about task number N.
5814 Print the task number of the current task.
5816 Switch the context of debugging to task number N.
5818 * Support for user-defined prefixed commands. The "define" command can
5819 add new commands to existing prefixes, e.g. "target".
5821 * Multi-inferior, multi-process debugging.
5823 GDB now has generalized support for multi-inferior debugging. See
5824 "Debugging Multiple Inferiors" in the manual for more information.
5825 Although availability still depends on target support, the command
5826 set is more uniform now. The GNU/Linux specific multi-forks support
5827 has been migrated to this new framework. This implied some user
5828 visible changes; see "New commands" and also "Removed commands"
5831 * Target descriptions can now describe the target OS ABI. See the
5832 "Target Description Format" section in the user manual for more
5835 * Target descriptions can now describe "compatible" architectures
5836 to indicate that the target can execute applications for a different
5837 architecture in addition to those for the main target architecture.
5838 See the "Target Description Format" section in the user manual for
5841 * Multi-architecture debugging.
5843 GDB now includes general supports for debugging applications on
5844 hybrid systems that use more than one single processor architecture
5845 at the same time. Each such hybrid architecture still requires
5846 specific support to be added. The only hybrid architecture supported
5847 in this version of GDB is the Cell Broadband Engine.
5849 * GDB now supports integrated debugging of Cell/B.E. applications that
5850 use both the PPU and SPU architectures. To enable support for hybrid
5851 Cell/B.E. debugging, you need to configure GDB to support both the
5852 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5853 --enable-targets configure option.
5855 * Non-stop mode debugging.
5857 For some targets, GDB now supports an optional mode of operation in
5858 which you can examine stopped threads while other threads continue
5859 to execute freely. This is referred to as non-stop mode, with the
5860 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5861 section in the user manual for more information.
5863 To be able to support remote non-stop debugging, a remote stub needs
5864 to implement the non-stop mode remote protocol extensions, as
5865 described in the "Remote Non-Stop" section of the user manual. The
5866 GDB remote stub, gdbserver, has been adjusted to support these
5867 extensions on linux targets.
5869 * New commands (for set/show, see "New options" below)
5871 catch syscall [NAME(S) | NUMBER(S)]
5872 Catch system calls. Arguments, which should be names of system
5873 calls or their numbers, mean catch only those syscalls. Without
5874 arguments, every syscall will be caught. When the inferior issues
5875 any of the specified syscalls, GDB will stop and announce the system
5876 call, both when it is called and when its call returns. This
5877 feature is currently available with a native GDB running on the
5878 Linux Kernel, under the following architectures: x86, x86_64,
5879 PowerPC and PowerPC64.
5881 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5883 Search memory for a sequence of bytes.
5885 maint set python print-stack
5886 maint show python print-stack
5887 Show a stack trace when an error is encountered in a Python script.
5890 Invoke CODE by passing it to the Python interpreter.
5895 These allow macros to be defined, undefined, and listed
5899 Show operating system information about processes.
5902 List the inferiors currently under GDB's control.
5905 Switch focus to inferior number NUM.
5908 Detach from inferior number NUM.
5911 Kill inferior number NUM.
5915 set spu stop-on-load
5916 show spu stop-on-load
5917 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5919 set spu auto-flush-cache
5920 show spu auto-flush-cache
5921 Control whether to automatically flush the software-managed cache
5922 during Cell/B.E. debugging.
5924 set sh calling-convention
5925 show sh calling-convention
5926 Control the calling convention used when calling SH target functions.
5929 show debug timestamp
5930 Control display of timestamps with GDB debugging output.
5932 set disassemble-next-line
5933 show disassemble-next-line
5934 Control display of disassembled source lines or instructions when
5937 set remote noack-packet
5938 show remote noack-packet
5939 Set/show the use of remote protocol QStartNoAckMode packet. See above
5940 under "New remote packets."
5942 set remote query-attached-packet
5943 show remote query-attached-packet
5944 Control use of remote protocol `qAttached' (query-attached) packet.
5946 set remote read-siginfo-object
5947 show remote read-siginfo-object
5948 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5951 set remote write-siginfo-object
5952 show remote write-siginfo-object
5953 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5956 set remote reverse-continue
5957 show remote reverse-continue
5958 Control use of remote protocol 'bc' (reverse-continue) packet.
5960 set remote reverse-step
5961 show remote reverse-step
5962 Control use of remote protocol 'bs' (reverse-step) packet.
5964 set displaced-stepping
5965 show displaced-stepping
5966 Control displaced stepping mode. Displaced stepping is a way to
5967 single-step over breakpoints without removing them from the debuggee.
5968 Also known as "out-of-line single-stepping".
5971 show debug displaced
5972 Control display of debugging info for displaced stepping.
5974 maint set internal-error
5975 maint show internal-error
5976 Control what GDB does when an internal error is detected.
5978 maint set internal-warning
5979 maint show internal-warning
5980 Control what GDB does when an internal warning is detected.
5985 Use a wrapper program to launch programs for debugging.
5987 set multiple-symbols (all|ask|cancel)
5988 show multiple-symbols
5989 The value of this variable can be changed to adjust the debugger behavior
5990 when an expression or a breakpoint location contains an ambiguous symbol
5991 name (an overloaded function name, for instance).
5993 set breakpoint always-inserted
5994 show breakpoint always-inserted
5995 Keep breakpoints always inserted in the target, as opposed to inserting
5996 them when resuming the target, and removing them when the target stops.
5997 This option can improve debugger performance on slow remote targets.
5999 set arm fallback-mode (arm|thumb|auto)
6000 show arm fallback-mode
6001 set arm force-mode (arm|thumb|auto)
6003 These commands control how ARM GDB determines whether instructions
6004 are ARM or Thumb. The default for both settings is auto, which uses
6005 the current CPSR value for instructions without symbols; previous
6006 versions of GDB behaved as if "set arm fallback-mode arm".
6008 set arm unwind-secure-frames
6009 Enable unwinding from Non-secure to Secure mode on Cortex-M with
6011 This can trigger security exceptions when unwinding exception stacks.
6013 set disable-randomization
6014 show disable-randomization
6015 Standalone programs run with the virtual address space randomization enabled
6016 by default on some platforms. This option keeps the addresses stable across
6017 multiple debugging sessions.
6021 Control whether other threads are stopped or not when some thread hits
6026 Requests that asynchronous execution is enabled in the target, if available.
6027 In this case, it's possible to resume target in the background, and interact
6028 with GDB while the target is running. "show target-async" displays the
6029 current state of asynchronous execution of the target.
6031 set target-wide-charset
6032 show target-wide-charset
6033 The target-wide-charset is the name of the character set that GDB
6034 uses when printing characters whose type is wchar_t.
6036 set tcp auto-retry (on|off)
6038 set tcp connect-timeout
6039 show tcp connect-timeout
6040 These commands allow GDB to retry failed TCP connections to a remote stub
6041 with a specified timeout period; this is useful if the stub is launched
6042 in parallel with GDB but may not be ready to accept connections immediately.
6044 set libthread-db-search-path
6045 show libthread-db-search-path
6046 Control list of directories which GDB will search for appropriate
6049 set schedule-multiple (on|off)
6050 show schedule-multiple
6051 Allow GDB to resume all threads of all processes or only threads of
6052 the current process.
6056 Use more aggressive caching for accesses to the stack. This improves
6057 performance of remote debugging (particularly backtraces) without
6058 affecting correctness.
6060 set interactive-mode (on|off|auto)
6061 show interactive-mode
6062 Control whether GDB runs in interactive mode (on) or not (off).
6063 When in interactive mode, GDB waits for the user to answer all
6064 queries. Otherwise, GDB does not wait and assumes the default
6065 answer. When set to auto (the default), GDB determines which
6066 mode to use based on the stdin settings.
6071 For program forks, this is replaced by the new more generic `info
6072 inferiors' command. To list checkpoints, you can still use the
6073 `info checkpoints' command, which was an alias for the `info forks'
6077 Replaced by the new `inferior' command. To switch between
6078 checkpoints, you can still use the `restart' command, which was an
6079 alias for the `fork' command.
6082 This is removed, since some targets don't have a notion of
6083 processes. To switch between processes, you can still use the
6084 `inferior' command using GDB's own inferior number.
6087 For program forks, this is replaced by the new more generic `kill
6088 inferior' command. To delete a checkpoint, you can still use the
6089 `delete checkpoint' command, which was an alias for the `delete
6093 For program forks, this is replaced by the new more generic `detach
6094 inferior' command. To detach a checkpoint, you can still use the
6095 `detach checkpoint' command, which was an alias for the `detach
6098 * New native configurations
6100 x86/x86_64 Darwin i[34567]86-*-darwin*
6102 x86_64 MinGW x86_64-*-mingw*
6106 Lattice Mico32 lm32-*
6107 x86 DICOS i[34567]86-*-dicos*
6108 x86_64 DICOS x86_64-*-dicos*
6111 * The GDB remote stub, gdbserver, now supports x86 Windows CE
6112 (mingw32ce) debugging.
6118 These commands were actually not implemented on any target.
6120 *** Changes in GDB 6.8
6122 * New native configurations
6124 NetBSD/hppa hppa*-*netbsd*
6125 Xtensa GNU/Linux xtensa*-*-linux*
6129 NetBSD/hppa hppa*-*-netbsd*
6130 Xtensa GNU/Linux xtensa*-*-linux*
6132 * Change in command line behavior -- corefiles vs. process ids.
6134 When the '-p NUMBER' or '--pid NUMBER' options are used, and
6135 attaching to process NUMBER fails, GDB no longer attempts to open a
6136 core file named NUMBER. Attaching to a program using the -c option
6137 is no longer supported. Instead, use the '-p' or '--pid' options.
6139 * GDB can now be built as a native debugger for debugging Windows x86
6140 (mingw32) Portable Executable (PE) programs.
6142 * Pending breakpoints no longer change their number when their address
6145 * GDB now supports breakpoints with multiple locations,
6146 including breakpoints on C++ constructors, inside C++ templates,
6147 and in inlined functions.
6149 * GDB's ability to debug optimized code has been improved. GDB more
6150 accurately identifies function bodies and lexical blocks that occupy
6151 more than one contiguous range of addresses.
6153 * Target descriptions can now describe registers for PowerPC.
6155 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
6156 registers on PowerPC targets.
6158 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
6159 targets even when the libthread_db library is not available.
6161 * The GDB remote stub, gdbserver, now supports the new file transfer
6162 commands (remote put, remote get, and remote delete).
6164 * The GDB remote stub, gdbserver, now supports run and attach in
6165 extended-remote mode.
6167 * hppa*64*-*-hpux11* target broken
6168 The debugger is unable to start a program and fails with the following
6169 error: "Error trying to get information about dynamic linker".
6170 The gdb-6.7 release is also affected.
6172 * GDB now supports the --enable-targets= configure option to allow
6173 building a single GDB executable that supports multiple remote
6174 target architectures.
6176 * GDB now supports debugging C and C++ programs which use the
6177 Decimal Floating Point extension. In addition, the PowerPC target
6178 now has a set of pseudo-registers to inspect decimal float values
6179 stored in two consecutive float registers.
6181 * The -break-insert MI command can optionally create pending
6184 * Improved support for debugging Ada
6185 Many improvements to the Ada language support have been made. These
6187 - Better support for Ada2005 interface types
6188 - Improved handling of arrays and slices in general
6189 - Better support for Taft-amendment types
6190 - The '{type} ADDRESS' expression is now allowed on the left hand-side
6192 - Improved command completion in Ada
6195 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
6200 set print frame-arguments (all|scalars|none)
6201 show print frame-arguments
6202 The value of this variable can be changed to control which argument
6203 values should be printed by the debugger when displaying a frame.
6208 Transfer files to and from a remote target, and delete remote files.
6215 Transfer files to and from a remote target, and delete remote files.
6217 * New remote packets
6224 Open, close, read, write, and delete files on the remote system.
6227 Attach to an existing process on the remote system, in extended-remote
6231 Run a new process on the remote system, in extended-remote mode.
6233 *** Changes in GDB 6.7
6235 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
6236 bfd, libiberty and opcodes, as revealed by static analysis donated by
6237 Coverity, Inc. (http://scan.coverity.com).
6239 * When looking up multiply-defined global symbols, GDB will now prefer the
6240 symbol definition in the current shared library if it was built using the
6241 -Bsymbolic linker option.
6243 * When the Text User Interface (TUI) is not configured, GDB will now
6244 recognize the -tui command-line option and print a message that the TUI
6247 * The GDB remote stub, gdbserver, now has lower overhead for high
6248 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
6250 * GDB for MIPS targets now autodetects whether a remote target provides
6251 32-bit or 64-bit register values.
6253 * Support for C++ member pointers has been improved.
6255 * GDB now understands XML target descriptions, which specify the
6256 target's overall architecture. GDB can read a description from
6257 a local file or over the remote serial protocol.
6259 * Vectors of single-byte data use a new integer type which is not
6260 automatically displayed as character or string data.
6262 * The /s format now works with the print command. It displays
6263 arrays of single-byte integers and pointers to single-byte integers
6266 * Target descriptions can now describe target-specific registers,
6267 for architectures which have implemented the support (currently
6268 only ARM, M68K, and MIPS).
6270 * GDB and the GDB remote stub, gdbserver, now support the XScale
6273 * The GDB remote stub, gdbserver, has been updated to support
6274 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6275 has been rewritten to use the standard GDB remote protocol.
6277 * GDB can now step into C++ functions which are called through thunks.
6279 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6281 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6282 layout. It also supports a TextSeg= and DataSeg= response when only
6283 segment base addresses (rather than offsets) are available.
6285 * The /i format now outputs any trailing branch delay slot instructions
6286 immediately following the last instruction within the count specified.
6288 * The GDB remote protocol "T" stop reply packet now supports a
6289 "library" response. Combined with the new "qXfer:libraries:read"
6290 packet, this response allows GDB to debug shared libraries on targets
6291 where the operating system manages the list of loaded libraries (e.g.
6292 Windows and SymbianOS).
6294 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6295 (DLLs) on Windows and Windows CE targets.
6297 * GDB now supports a faster verification that a .debug file matches its binary
6298 according to its build-id signature, if the signature is present.
6304 Enable or disable hardware flow control (RTS/CTS) on the serial port
6305 when debugging using remote targets.
6307 set mem inaccessible-by-default
6308 show mem inaccessible-by-default
6309 If the target supplies a memory map, for instance via the remote
6310 protocol's "qXfer:memory-map:read" packet, setting this variable
6311 prevents GDB from accessing memory outside the memory map. This
6312 is useful for targets with memory mapped registers or which react
6313 badly to accesses of unmapped address space.
6315 set breakpoint auto-hw
6316 show breakpoint auto-hw
6317 If the target supplies a memory map, for instance via the remote
6318 protocol's "qXfer:memory-map:read" packet, setting this variable
6319 lets GDB use hardware breakpoints automatically for memory regions
6320 where it can not use software breakpoints. This covers both the
6321 "break" command and internal breakpoints used for other commands
6322 including "next" and "finish".
6325 catch exception unhandled
6326 Stop the program execution when Ada exceptions are raised.
6329 Stop the program execution when an Ada assertion failed.
6333 Set an alternate system root for target files. This is a more
6334 general version of "set solib-absolute-prefix", which is now
6335 an alias to "set sysroot".
6338 Provide extended SPU facility status information. This set of
6339 commands is available only when debugging the Cell/B.E. SPU
6342 * New native configurations
6344 OpenBSD/sh sh*-*openbsd*
6347 unset tdesc filename
6349 Use the specified local file as an XML target description, and do
6350 not query the target for its built-in description.
6354 OpenBSD/sh sh*-*-openbsd*
6355 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
6356 Toshiba Media Processor mep-elf
6358 * New remote packets
6361 Ignore the specified signals; pass them directly to the debugged program
6362 without stopping other threads or reporting them to GDB.
6364 qXfer:features:read:
6365 Read an XML target description from the target, which describes its
6370 Read or write contents of an spufs file on the target system. These
6371 packets are available only on the Cell/B.E. SPU architecture.
6373 qXfer:libraries:read:
6374 Report the loaded shared libraries. Combined with new "T" packet
6375 response, this packet allows GDB to debug shared libraries on
6376 targets where the operating system manages the list of loaded
6377 libraries (e.g. Windows and SymbianOS).
6381 Support for these obsolete configurations has been removed.
6389 i[34567]86-*-lynxos*
6390 i[34567]86-*-netware*
6391 i[34567]86-*-sco3.2v5*
6392 i[34567]86-*-sco3.2v4*
6394 i[34567]86-*-sysv4.2*
6397 i[34567]86-*-unixware2*
6398 i[34567]86-*-unixware*
6407 * Other removed features
6414 Various m68k-only ROM monitors.
6421 Various Renesas ROM monitors and debugging interfaces for SH and
6426 Support for a Macraigor serial interface to on-chip debugging.
6427 GDB does not directly support the newer parallel or USB
6432 A debug information format. The predecessor to DWARF 2 and
6433 DWARF 3, which are still supported.
6435 Support for the HP aCC compiler on HP-UX/PA-RISC
6437 SOM-encapsulated symbolic debugging information, automatic
6438 invocation of pxdb, and the aCC custom C++ ABI. This does not
6439 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6440 with aCC can still be debugged on an assembly level.
6442 MIPS ".pdr" sections
6444 A MIPS-specific format used to describe stack frame layout
6445 in debugging information.
6449 GDB could work with an older version of Guile to debug
6450 the interpreter and Scheme programs running in it.
6452 set mips stack-arg-size
6453 set mips saved-gpreg-size
6455 Use "set mips abi" to control parameter passing for MIPS.
6457 *** Changes in GDB 6.6
6462 Cell Broadband Engine SPU spu-elf
6464 * GDB can now be configured as a cross-debugger targeting native Windows
6465 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6466 running on a Windows system over TCP/IP to debug Windows programs.
6468 * The GDB remote stub, gdbserver, has been updated to support Windows and
6469 Cygwin debugging. Both single-threaded and multi-threaded programs are
6472 * The "set trust-readonly-sections" command works again. This command was
6473 broken in GDB 6.3, 6.4, and 6.5.
6475 * The "load" command now supports writing to flash memory, if the remote
6476 stub provides the required support.
6478 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
6479 longer requires symbolic debug information (e.g. DWARF-2).
6484 unset substitute-path
6485 show substitute-path
6486 Manage a list of substitution rules that GDB uses to rewrite the name
6487 of the directories where the sources are located. This can be useful
6488 for instance when the sources were moved to a different location
6489 between compilation and debugging.
6493 Print each CLI command as it is executed. Each command is prefixed with
6494 a number of `+' symbols representing the nesting depth.
6495 The source command now has a `-v' option to enable the same feature.
6499 The ARM Demon monitor support (RDP protocol, "target rdp").
6501 Kernel Object Display, an embedded debugging feature which only worked with
6502 an obsolete version of Cisco IOS.
6504 The 'set download-write-size' and 'show download-write-size' commands.
6506 * New remote packets
6509 Tell a stub about GDB client features, and request remote target features.
6510 The first feature implemented is PacketSize, which allows the target to
6511 specify the size of packets it can handle - to minimize the number of
6512 packets required and improve performance when connected to a remote
6516 Fetch an OS auxilliary vector from the remote stub. This packet is a
6517 more efficient replacement for qPart:auxv:read.
6519 qXfer:memory-map:read:
6520 Fetch a memory map from the remote stub, including information about
6521 RAM, ROM, and flash memory devices.
6526 Erase and program a flash memory device.
6528 * Removed remote packets
6531 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
6532 used it, and only gdbserver implemented it.
6534 *** Changes in GDB 6.5
6538 Renesas M32C/M16C m32c-elf
6540 Morpho Technologies ms1 ms1-elf
6544 init-if-undefined Initialize a convenience variable, but
6545 only if it doesn't already have a value.
6547 The following commands are presently only implemented for native GNU/Linux:
6549 checkpoint Save a snapshot of the program state.
6551 restart <n> Return the program state to a
6552 previously saved state.
6554 info checkpoints List currently saved checkpoints.
6556 delete-checkpoint <n> Delete a previously saved checkpoint.
6558 set|show detach-on-fork Tell gdb whether to detach from a newly
6559 forked process, or to keep debugging it.
6561 info forks List forks of the user program that
6562 are available to be debugged.
6564 fork <n> Switch to debugging one of several
6565 forks of the user program that are
6566 available to be debugged.
6568 delete-fork <n> Delete a fork from the list of forks
6569 that are available to be debugged (and
6570 kill the forked process).
6572 detach-fork <n> Delete a fork from the list of forks
6573 that are available to be debugged (and
6574 allow the process to continue).
6578 Morpho Technologies ms2 ms1-elf
6580 * Improved Windows host support
6582 GDB now builds as a cross debugger hosted on i686-mingw32, including
6583 native console support, and remote communications using either
6584 network sockets or serial ports.
6586 * Improved Modula-2 language support
6588 GDB can now print most types in the Modula-2 syntax. This includes:
6589 basic types, set types, record types, enumerated types, range types,
6590 pointer types and ARRAY types. Procedure var parameters are correctly
6591 printed and hexadecimal addresses and character constants are also
6592 written in the Modula-2 syntax. Best results can be obtained by using
6593 GNU Modula-2 together with the -gdwarf-2 command line option.
6597 The ARM rdi-share module.
6599 The Netware NLM debug server.
6601 *** Changes in GDB 6.4
6603 * New native configurations
6605 OpenBSD/arm arm*-*-openbsd*
6606 OpenBSD/mips64 mips64-*-openbsd*
6610 Morpho Technologies ms1 ms1-elf
6612 * New command line options
6614 --batch-silent As for --batch, but totally silent.
6615 --return-child-result The debugger will exist with the same value
6616 the child (debugged) program exited with.
6617 --eval-command COMMAND, -ex COMMAND
6618 Execute a single GDB CLI command. This may be
6619 specified multiple times and in conjunction
6620 with the --command (-x) option.
6622 * Deprecated commands removed
6624 The following commands, that were deprecated in 2000, have been
6628 set|show arm disassembly-flavor set|show arm disassembler
6629 othernames set arm disassembler
6630 set|show remotedebug set|show debug remote
6631 set|show archdebug set|show debug arch
6632 set|show eventdebug set|show debug event
6635 * New BSD user-level threads support
6637 It is now possible to debug programs using the user-level threads
6638 library on OpenBSD and FreeBSD. Currently supported (target)
6641 FreeBSD/amd64 x86_64-*-freebsd*
6642 FreeBSD/i386 i386-*-freebsd*
6643 OpenBSD/i386 i386-*-openbsd*
6645 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6646 are not yet supported.
6648 * New support for Matsushita MN10300 w/sim added
6649 (Work in progress). mn10300-elf.
6651 * REMOVED configurations and files
6653 VxWorks and the XDR protocol *-*-vxworks
6654 Motorola MCORE mcore-*-*
6655 National Semiconductor NS32000 ns32k-*-*
6657 * New "set print array-indexes" command
6659 After turning this setting "on", GDB prints the index of each element
6660 when displaying arrays. The default is "off" to preserve the previous
6663 * VAX floating point support
6665 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6667 * User-defined command support
6669 In addition to using $arg0..$arg9 for argument passing, it is now possible
6670 to use $argc to determine now many arguments have been passed. See the
6671 section on user-defined commands in the user manual for more information.
6673 *** Changes in GDB 6.3:
6675 * New command line option
6677 GDB now accepts -l followed by a number to set the timeout for remote
6680 * GDB works with GCC -feliminate-dwarf2-dups
6682 GDB now supports a more compact representation of DWARF-2 debug
6683 information using DW_FORM_ref_addr references. These are produced
6684 by GCC with the option -feliminate-dwarf2-dups and also by some
6685 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6686 to use -feliminate-dwarf2-dups.
6688 * Internationalization
6690 When supported by the host system, GDB will be built with
6691 internationalization (libintl). The task of marking up the sources is
6692 continued, we're looking forward to our first translation.
6696 Initial support for debugging programs compiled with the GNAT
6697 implementation of the Ada programming language has been integrated
6698 into GDB. In this release, support is limited to expression evaluation.
6700 * New native configurations
6702 GNU/Linux/m32r m32r-*-linux-gnu
6706 GDB's remote protocol now includes support for the 'p' packet. This
6707 packet is used to fetch individual registers from a remote inferior.
6709 * END-OF-LIFE registers[] compatibility module
6711 GDB's internal register infrastructure has been completely rewritten.
6712 The new infrastructure making possible the implementation of key new
6713 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6716 GDB 6.3 will be the last release to include the registers[]
6717 compatibility module that allowed out-of-date configurations to
6718 continue to work. This change directly impacts the following
6728 powerpc bdm protocol
6730 Unless there is activity to revive these configurations, they will be
6731 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6733 * OBSOLETE configurations and files
6735 Configurations that have been declared obsolete in this release have
6736 been commented out. Unless there is activity to revive these
6737 configurations, the next release of GDB will have their sources
6738 permanently REMOVED.
6747 *** Changes in GDB 6.2.1:
6749 * MIPS `break main; run' gave an heuristic-fence-post warning
6751 When attempting to run even a simple program, a warning about
6752 heuristic-fence-post being hit would be reported. This problem has
6755 * MIPS IRIX 'long double' crashed GDB
6757 When examining a long double variable, GDB would get a segmentation
6758 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6759 IRIX long double values).
6763 A bug in the VAX stack code was causing problems with the "next"
6764 command. This problem has been fixed.
6766 *** Changes in GDB 6.2:
6768 * Fix for ``many threads''
6770 On GNU/Linux systems that use the NPTL threads library, a program
6771 rapidly creating and deleting threads would confuse GDB leading to the
6774 ptrace: No such process.
6775 thread_db_get_info: cannot get thread info: generic error
6777 This problem has been fixed.
6779 * "-async" and "-noasync" options removed.
6781 Support for the broken "-noasync" option has been removed (it caused
6784 * New ``start'' command.
6786 This command runs the program until the beginning of the main procedure.
6788 * New BSD Kernel Data Access Library (libkvm) interface
6790 Using ``target kvm'' it is now possible to debug kernel core dumps and
6791 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6792 platforms. Currently supported (native-only) configurations are:
6794 FreeBSD/amd64 x86_64-*-freebsd*
6795 FreeBSD/i386 i?86-*-freebsd*
6796 NetBSD/i386 i?86-*-netbsd*
6797 NetBSD/m68k m68*-*-netbsd*
6798 NetBSD/sparc sparc-*-netbsd*
6799 OpenBSD/amd64 x86_64-*-openbsd*
6800 OpenBSD/i386 i?86-*-openbsd*
6801 OpenBSD/m68k m68*-openbsd*
6802 OpenBSD/sparc sparc-*-openbsd*
6804 * Signal trampoline code overhauled
6806 Many generic problems with GDB's signal handling code have been fixed.
6807 These include: backtraces through non-contiguous stacks; recognition
6808 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6809 call; backtrace through a signal trampoline; step into and out of
6810 signal handlers; and single-stepping in the signal trampoline.
6812 Please note that kernel bugs are a limiting factor here. These
6813 features have been shown to work on an s390 GNU/Linux system that
6814 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6816 * Cygwin support for DWARF 2 added.
6818 * New native configurations
6820 GNU/Linux/hppa hppa*-*-linux*
6821 OpenBSD/hppa hppa*-*-openbsd*
6822 OpenBSD/m68k m68*-*-openbsd*
6823 OpenBSD/m88k m88*-*-openbsd*
6824 OpenBSD/powerpc powerpc-*-openbsd*
6825 NetBSD/vax vax-*-netbsd*
6826 OpenBSD/vax vax-*-openbsd*
6828 * END-OF-LIFE frame compatibility module
6830 GDB's internal frame infrastructure has been completely rewritten.
6831 The new infrastructure making it possible to support key new features
6832 including DWARF 2 Call Frame Information. To aid in the task of
6833 migrating old configurations to this new infrastructure, a
6834 compatibility module, that allowed old configurations to continue to
6835 work, was also included.
6837 GDB 6.2 will be the last release to include this frame compatibility
6838 module. This change directly impacts the following configurations:
6848 Unless there is activity to revive these configurations, they will be
6849 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6851 * REMOVED configurations and files
6853 Sun 3, running SunOS 3 m68*-*-sunos3*
6854 Sun 3, running SunOS 4 m68*-*-sunos4*
6855 Sun 2, running SunOS 3 m68000-*-sunos3*
6856 Sun 2, running SunOS 4 m68000-*-sunos4*
6857 Motorola 680x0 running LynxOS m68*-*-lynxos*
6858 AT&T 3b1/Unix pc m68*-att-*
6859 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6860 decstation mips-dec-* mips-little-*
6861 riscos mips-*-riscos* mips-*-sysv*
6862 sonymips mips-sony-*
6863 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6865 *** Changes in GDB 6.1.1:
6867 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6869 The TUI (Text-mode User Interface) is now built as part of a default
6870 GDB configuration. It is enabled by either selecting the TUI with the
6871 command line option "-i=tui" or by running the separate "gdbtui"
6872 program. For more information on the TUI, see the manual "Debugging
6875 * Pending breakpoint support (also included in GDB 6.1)
6877 Support has been added to allow you to specify breakpoints in shared
6878 libraries that have not yet been loaded. If a breakpoint location
6879 cannot be found, and the "breakpoint pending" option is set to auto,
6880 GDB queries you if you wish to make the breakpoint pending on a future
6881 shared-library load. If and when GDB resolves the breakpoint symbol,
6882 the pending breakpoint is removed as one or more regular breakpoints
6885 Pending breakpoints are very useful for GCJ Java debugging.
6887 * Fixed ISO-C build problems
6889 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6890 non ISO-C code that stopped them being built using a more strict ISO-C
6891 compiler (e.g., IBM's C compiler).
6893 * Fixed build problem on IRIX 5
6895 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6896 wasn't able to compile compile on an IRIX 5 system.
6898 * Added execute permission to gdb/gdbserver/configure
6900 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6901 permission. This bug would cause configure to fail on a number of
6902 systems (Solaris, IRIX). Ref: server/519.
6904 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6906 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6907 has been updated to use constant array sizes.
6909 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6911 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6912 its generated DWARF Call Frame Info. This encoding was causing GDB to
6913 panic, that panic has been fixed. Ref: gdb/1628.
6915 * Fixed a problem when examining parameters in shared library code.
6917 When examining parameters in optimized shared library code generated
6918 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6919 not available''. GDB now correctly displays the variable's value.
6921 *** Changes in GDB 6.1:
6923 * Removed --with-mmalloc
6925 Support for the mmalloc memory manager has been removed, as it
6926 conflicted with the internal gdb byte cache.
6928 * Changes in AMD64 configurations
6930 The AMD64 target now includes the %cs and %ss registers. As a result
6931 the AMD64 remote protocol has changed; this affects the floating-point
6932 and SSE registers. If you rely on those registers for your debugging,
6933 you should upgrade gdbserver on the remote side.
6935 * Revised SPARC target
6937 The SPARC target has been completely revised, incorporating the
6938 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6939 support for LynxOS and SunOS 4 has been dropped. Calling functions
6940 from within GDB on operating systems with a non-executable stack
6941 (Solaris, OpenBSD) now works.
6945 GDB has a new C++ demangler which does a better job on the mangled
6946 names generated by current versions of g++. It also runs faster, so
6947 with this and other changes gdb should now start faster on large C++
6950 * DWARF 2 Location Expressions
6952 GDB support for location expressions has been extended to support function
6953 arguments and frame bases. Older versions of GDB could crash when they
6956 * C++ nested types and namespaces
6958 GDB's support for nested types and namespaces in C++ has been
6959 improved, especially if you use the DWARF 2 debugging format. (This
6960 is the default for recent versions of GCC on most platforms.)
6961 Specifically, if you have a class "Inner" defined within a class or
6962 namespace "Outer", then GDB realizes that the class's name is
6963 "Outer::Inner", not simply "Inner". This should greatly reduce the
6964 frequency of complaints about not finding RTTI symbols. In addition,
6965 if you are stopped at inside of a function defined within a namespace,
6966 GDB modifies its name lookup accordingly.
6968 * New native configurations
6970 NetBSD/amd64 x86_64-*-netbsd*
6971 OpenBSD/amd64 x86_64-*-openbsd*
6972 OpenBSD/alpha alpha*-*-openbsd*
6973 OpenBSD/sparc sparc-*-openbsd*
6974 OpenBSD/sparc64 sparc64-*-openbsd*
6976 * New debugging protocols
6978 M32R with SDI protocol m32r-*-elf*
6980 * "set prompt-escape-char" command deleted.
6982 The command "set prompt-escape-char" has been deleted. This command,
6983 and its very obscure effect on GDB's prompt, was never documented,
6984 tested, nor mentioned in the NEWS file.
6986 * OBSOLETE configurations and files
6988 Configurations that have been declared obsolete in this release have
6989 been commented out. Unless there is activity to revive these
6990 configurations, the next release of GDB will have their sources
6991 permanently REMOVED.
6993 Sun 3, running SunOS 3 m68*-*-sunos3*
6994 Sun 3, running SunOS 4 m68*-*-sunos4*
6995 Sun 2, running SunOS 3 m68000-*-sunos3*
6996 Sun 2, running SunOS 4 m68000-*-sunos4*
6997 Motorola 680x0 running LynxOS m68*-*-lynxos*
6998 AT&T 3b1/Unix pc m68*-att-*
6999 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
7000 decstation mips-dec-* mips-little-*
7001 riscos mips-*-riscos* mips-*-sysv*
7002 sonymips mips-sony-*
7003 sysv mips*-*-sysv4* (IRIX 5/6 not included)
7005 * REMOVED configurations and files
7007 SGI Irix-4.x mips-sgi-irix4 or iris4
7008 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7009 Z8000 simulator z8k-zilog-none or z8ksim
7010 Matsushita MN10200 w/simulator mn10200-*-*
7011 H8/500 simulator h8500-hitachi-hms or h8500hms
7012 HP/PA running BSD hppa*-*-bsd*
7013 HP/PA running OSF/1 hppa*-*-osf*
7014 HP/PA Pro target hppa*-*-pro*
7015 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
7016 386BSD i[3456]86-*-bsd*
7017 Sequent family i[3456]86-sequent-sysv4*
7018 i[3456]86-sequent-sysv*
7019 i[3456]86-sequent-bsd*
7020 SPARC running LynxOS sparc-*-lynxos*
7021 SPARC running SunOS 4 sparc-*-sunos4*
7022 Tsqware Sparclet sparclet-*-*
7023 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7025 *** Changes in GDB 6.0:
7029 Support for debugging the Objective-C programming language has been
7030 integrated into GDB.
7032 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
7034 DWARF 2's Call Frame Information makes available compiler generated
7035 information that more exactly describes the program's run-time stack.
7036 By using this information, GDB is able to provide more robust stack
7039 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
7040 have been updated to use a new backtrace mechanism which includes
7041 DWARF 2 CFI support.
7045 GDB's remote protocol has been extended to include support for hosted
7046 file I/O (where the remote target uses GDB's file system). See GDB's
7047 remote protocol documentation for details.
7049 * All targets using the new architecture framework.
7051 All of GDB's targets have been updated to use the new internal
7052 architecture framework. The way is now open for future GDB releases
7053 to include cross-architecture native debugging support (i386 on amd64,
7056 * GNU/Linux's Thread Local Storage (TLS)
7058 GDB now includes support for for the GNU/Linux implementation of
7059 per-thread variables.
7061 * GNU/Linux's Native POSIX Thread Library (NPTL)
7063 GDB's thread code has been updated to work with either the new
7064 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
7066 * Separate debug info.
7068 GDB, in conjunction with BINUTILS, now supports a mechanism for
7069 automatically loading debug information from a separate file. Instead
7070 of shipping full debug and non-debug versions of system libraries,
7071 system integrators can now instead ship just the stripped libraries
7072 and optional debug files.
7074 * DWARF 2 Location Expressions
7076 DWARF 2 Location Expressions allow the compiler to more completely
7077 describe the location of variables (even in optimized code) to the
7080 GDB now includes preliminary support for location expressions (support
7081 for DW_OP_piece is still missing).
7085 A number of long standing bugs that caused GDB to die while starting a
7086 Java application have been fixed. GDB's Java support is now
7087 considered "useable".
7089 * GNU/Linux support for fork, vfork, and exec.
7091 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
7092 commands are now implemented for GNU/Linux. They require a 2.5.x or later
7095 * GDB supports logging output to a file
7097 There are two new commands, "set logging" and "show logging", which can be
7098 used to capture GDB's output to a file.
7100 * The meaning of "detach" has changed for gdbserver
7102 The "detach" command will now resume the application, as documented. To
7103 disconnect from gdbserver and leave it stopped, use the new "disconnect"
7106 * d10v, m68hc11 `regs' command deprecated
7108 The `info registers' command has been updated so that it displays the
7109 registers using a format identical to the old `regs' command.
7113 A new command, "maint set profile on/off", has been added. This command can
7114 be used to enable or disable profiling while running GDB, to profile a
7115 session or a set of commands. In addition there is a new configure switch,
7116 "--enable-profiling", which will cause GDB to be compiled with profiling
7117 data, for more informative profiling results.
7119 * Default MI syntax changed to "mi2".
7121 The default MI (machine interface) syntax, enabled by the command line
7122 option "-i=mi", has been changed to "mi2". The previous MI syntax,
7123 "mi1", can be enabled by specifying the option "-i=mi1".
7125 Support for the original "mi0" syntax (included in GDB 5.0) has been
7128 Fix for gdb/192: removed extraneous space when displaying frame level.
7129 Fix for gdb/672: update changelist is now output in mi list format.
7130 Fix for gdb/702: a -var-assign that updates the value now shows up
7131 in a subsequent -var-update.
7133 * New native configurations.
7135 FreeBSD/amd64 x86_64-*-freebsd*
7137 * Multi-arched targets.
7139 HP/PA HPUX11 hppa*-*-hpux*
7140 Renesas M32R/D w/simulator m32r-*-elf*
7142 * OBSOLETE configurations and files
7144 Configurations that have been declared obsolete in this release have
7145 been commented out. Unless there is activity to revive these
7146 configurations, the next release of GDB will have their sources
7147 permanently REMOVED.
7149 Z8000 simulator z8k-zilog-none or z8ksim
7150 Matsushita MN10200 w/simulator mn10200-*-*
7151 H8/500 simulator h8500-hitachi-hms or h8500hms
7152 HP/PA running BSD hppa*-*-bsd*
7153 HP/PA running OSF/1 hppa*-*-osf*
7154 HP/PA Pro target hppa*-*-pro*
7155 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
7156 Sequent family i[3456]86-sequent-sysv4*
7157 i[3456]86-sequent-sysv*
7158 i[3456]86-sequent-bsd*
7159 Tsqware Sparclet sparclet-*-*
7160 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7162 * REMOVED configurations and files
7165 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7166 IBM AIX PS/2 i[3456]86-*-aix
7167 i386 running Mach 3.0 i[3456]86-*-mach3*
7168 i386 running Mach i[3456]86-*-mach*
7169 i386 running OSF/1 i[3456]86-*osf1mk*
7170 HP/Apollo 68k Family m68*-apollo*-sysv*,
7172 m68*-hp-bsd*, m68*-hp-hpux*
7173 Argonaut Risc Chip (ARC) arc-*-*
7174 Mitsubishi D30V d30v-*-*
7175 Fujitsu FR30 fr30-*-elf*
7176 OS/9000 i[34]86-*-os9k
7177 I960 with MON960 i960-*-coff
7179 * MIPS $fp behavior changed
7181 The convenience variable $fp, for the MIPS, now consistently returns
7182 the address of the current frame's base. Previously, depending on the
7183 context, $fp could refer to either $sp or the current frame's base
7184 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
7185 The GNU Source-Level Debugger''.
7187 *** Changes in GDB 5.3:
7189 * GNU/Linux shared library multi-threaded performance improved.
7191 When debugging a multi-threaded application on GNU/Linux, GDB now uses
7192 `/proc', in preference to `ptrace' for memory reads. This may result
7193 in an improvement in the start-up time of multi-threaded, shared
7194 library applications when run under GDB. One GDB user writes: ``loads
7195 shared libs like mad''.
7197 * ``gdbserver'' now supports multi-threaded applications on some targets
7199 Support for debugging multi-threaded applications which use
7200 the GNU/Linux LinuxThreads package has been added for
7201 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
7202 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
7204 * GDB now supports C/C++ preprocessor macros.
7206 GDB now expands preprocessor macro invocations in C/C++ expressions,
7207 and provides various commands for showing macro definitions and how
7210 The new command `macro expand EXPRESSION' expands any macro
7211 invocations in expression, and shows the result.
7213 The new command `show macro MACRO-NAME' shows the definition of the
7214 macro named MACRO-NAME, and where it was defined.
7216 Most compilers don't include information about macros in the debugging
7217 information by default. In GCC 3.1, for example, you need to compile
7218 your program with the options `-gdwarf-2 -g3'. If the macro
7219 information is present in the executable, GDB will read it.
7221 * Multi-arched targets.
7223 DEC Alpha (partial) alpha*-*-*
7224 DEC VAX (partial) vax-*-*
7226 National Semiconductor NS32000 (partial) ns32k-*-*
7227 Motorola 68000 (partial) m68k-*-*
7228 Motorola MCORE mcore-*-*
7232 Fujitsu FRV architecture added by Red Hat frv*-*-*
7235 * New native configurations
7237 Alpha NetBSD alpha*-*-netbsd*
7238 SH NetBSD sh*-*-netbsdelf*
7239 MIPS NetBSD mips*-*-netbsd*
7240 UltraSPARC NetBSD sparc64-*-netbsd*
7242 * OBSOLETE configurations and files
7244 Configurations that have been declared obsolete in this release have
7245 been commented out. Unless there is activity to revive these
7246 configurations, the next release of GDB will have their sources
7247 permanently REMOVED.
7249 Mitsubishi D30V d30v-*-*
7250 OS/9000 i[34]86-*-os9k
7251 IBM AIX PS/2 i[3456]86-*-aix
7252 Fujitsu FR30 fr30-*-elf*
7253 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7254 Argonaut Risc Chip (ARC) arc-*-*
7255 i386 running Mach 3.0 i[3456]86-*-mach3*
7256 i386 running Mach i[3456]86-*-mach*
7257 i386 running OSF/1 i[3456]86-*osf1mk*
7258 HP/Apollo 68k Family m68*-apollo*-sysv*,
7260 m68*-hp-bsd*, m68*-hp-hpux*
7261 I960 with MON960 i960-*-coff
7263 * OBSOLETE languages
7265 CHILL, a Pascal like language used by telecommunications companies.
7267 * REMOVED configurations and files
7269 AMD 29k family via UDI a29k-amd-udi, udi29k
7270 A29K VxWorks a29k-*-vxworks
7271 AMD 29000 embedded, using EBMON a29k-none-none
7272 AMD 29000 embedded with COFF a29k-none-coff
7273 AMD 29000 embedded with a.out a29k-none-aout
7275 testsuite/gdb.hp/gdb.threads-hp/ directory
7277 * New command "set max-user-call-depth <nnn>"
7279 This command allows the user to limit the call depth of user-defined
7280 commands. The default is 1024.
7282 * Changes in FreeBSD/i386 native debugging.
7284 Support for the "generate-core-file" has been added.
7286 * New commands "dump", "append", and "restore".
7288 These commands allow data to be copied from target memory
7289 to a bfd-format or binary file (dump and append), and back
7290 from a file into memory (restore).
7292 * Improved "next/step" support on multi-processor Alpha Tru64.
7294 The previous single-step mechanism could cause unpredictable problems,
7295 including the random appearance of SIGSEGV or SIGTRAP signals. The use
7296 of a software single-step mechanism prevents this.
7298 *** Changes in GDB 5.2.1:
7306 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
7307 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
7308 Fix, by Joel Brobecker imported from mainline.
7310 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
7311 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
7312 Fix, by Fred Fish, imported from mainline.
7314 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
7315 Surprisingly enough, it works now.
7316 By Michal Ludvig, imported from mainline.
7318 i386 hardware watchpoint support:
7319 avoid misses on second run for some targets.
7320 By Pierre Muller, imported from mainline.
7322 *** Changes in GDB 5.2:
7324 * New command "set trust-readonly-sections on[off]".
7326 This command is a hint that tells gdb that read-only sections
7327 really are read-only (ie. that their contents will not change).
7328 In this mode, gdb will go to the object file rather than the
7329 target to read memory from read-only sections (such as ".text").
7330 This can be a significant performance improvement on some
7331 (notably embedded) targets.
7333 * New command "generate-core-file" (or "gcore").
7335 This new gdb command allows the user to drop a core file of the child
7336 process state at any time. So far it's been implemented only for
7337 GNU/Linux and Solaris, but should be relatively easily ported to other
7338 hosts. Argument is core file name (defaults to core.<pid>).
7340 * New command line option
7342 GDB now accepts --pid or -p followed by a process id.
7344 * Change in command line behavior -- corefiles vs. process ids.
7346 There is a subtle behavior in the way in which GDB handles
7347 command line arguments. The first non-flag argument is always
7348 a program to debug, but the second non-flag argument may either
7349 be a corefile or a process id. Previously, GDB would attempt to
7350 open the second argument as a corefile, and if that failed, would
7351 issue a superfluous error message and then attempt to attach it as
7352 a process. Now, if the second argument begins with a non-digit,
7353 it will be treated as a corefile. If it begins with a digit,
7354 GDB will attempt to attach it as a process, and if no such process
7355 is found, will then attempt to open it as a corefile.
7357 * Changes in ARM configurations.
7359 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
7360 configuration is fully multi-arch.
7362 * New native configurations
7364 ARM NetBSD arm*-*-netbsd*
7365 x86 OpenBSD i[3456]86-*-openbsd*
7366 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7367 Sparc64 running FreeBSD sparc64-*-freebsd*
7371 Sanyo XStormy16 xstormy16-elf
7373 * OBSOLETE configurations and files
7375 Configurations that have been declared obsolete in this release have
7376 been commented out. Unless there is activity to revive these
7377 configurations, the next release of GDB will have their sources
7378 permanently REMOVED.
7380 AMD 29k family via UDI a29k-amd-udi, udi29k
7381 A29K VxWorks a29k-*-vxworks
7382 AMD 29000 embedded, using EBMON a29k-none-none
7383 AMD 29000 embedded with COFF a29k-none-coff
7384 AMD 29000 embedded with a.out a29k-none-aout
7386 testsuite/gdb.hp/gdb.threads-hp/ directory
7388 * REMOVED configurations and files
7390 TI TMS320C80 tic80-*-*
7392 PowerPC Solaris powerpcle-*-solaris*
7393 PowerPC Windows NT powerpcle-*-cygwin32
7394 PowerPC Netware powerpc-*-netware*
7395 Harris/CXUX m88k m88*-harris-cxux*
7396 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7397 ns32k-utek-sysv* ns32k-utek-*
7398 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7399 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7400 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7401 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7402 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7404 * Changes to command line processing
7406 The new `--args' feature can be used to specify command-line arguments
7407 for the inferior from gdb's command line.
7409 * Changes to key bindings
7411 There is a new `operate-and-get-next' function bound to `C-o'.
7413 *** Changes in GDB 5.1.1
7415 Fix compile problem on DJGPP.
7417 Fix a problem with floating-point registers on the i386 being
7420 Fix to stop GDB crashing on .debug_str debug info.
7422 Numerous documentation fixes.
7424 Numerous testsuite fixes.
7426 *** Changes in GDB 5.1:
7428 * New native configurations
7430 Alpha FreeBSD alpha*-*-freebsd*
7431 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7432 MIPS GNU/Linux mips*-*-linux*
7433 MIPS SGI Irix 6.x mips*-sgi-irix6*
7434 ia64 AIX ia64-*-aix*
7435 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7439 Motorola 68HC11 and 68HC12 m68hc11-elf
7441 UltraSparc running GNU/Linux sparc64-*-linux*
7443 * OBSOLETE configurations and files
7445 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7446 Harris/CXUX m88k m88*-harris-cxux*
7447 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7448 ns32k-utek-sysv* ns32k-utek-*
7449 TI TMS320C80 tic80-*-*
7451 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7452 PowerPC Solaris powerpcle-*-solaris*
7453 PowerPC Windows NT powerpcle-*-cygwin32
7454 PowerPC Netware powerpc-*-netware*
7455 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7456 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7457 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7458 Apple Macintosh (MPW) host N/A
7460 stuff.c (Program to stuff files into a specially prepared space in kdb)
7461 kdb-start.c (Main loop for the standalone kernel debugger)
7463 Configurations that have been declared obsolete in this release have
7464 been commented out. Unless there is activity to revive these
7465 configurations, the next release of GDB will have their sources
7466 permanently REMOVED.
7468 * REMOVED configurations and files
7470 Altos 3068 m68*-altos-*
7471 Convex c1-*-*, c2-*-*
7473 ARM RISCix arm-*-* (as host)
7477 * GDB has been converted to ISO C.
7479 GDB's source code has been converted to ISO C. In particular, the
7480 sources are fully protoized, and rely on standard headers being
7485 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
7487 * The MI enabled by default.
7489 The new machine oriented interface (MI) introduced in GDB 5.0 has been
7490 revised and enabled by default. Packages which use GDB as a debugging
7491 engine behind a UI or another front end are encouraged to switch to
7492 using the GDB/MI interface, instead of the old annotations interface
7493 which is now deprecated.
7495 * Support for debugging Pascal programs.
7497 GDB now includes support for debugging Pascal programs. The following
7498 main features are supported:
7500 - Pascal-specific data types such as sets;
7502 - automatic recognition of Pascal sources based on file-name
7505 - Pascal-style display of data types, variables, and functions;
7507 - a Pascal expression parser.
7509 However, some important features are not yet supported.
7511 - Pascal string operations are not supported at all;
7513 - there are some problems with boolean types;
7515 - Pascal type hexadecimal constants are not supported
7516 because they conflict with the internal variables format;
7518 - support for Pascal objects and classes is not full yet;
7520 - unlike Pascal, GDB is case-sensitive for symbol names.
7522 * Changes in completion.
7524 Commands such as `shell', `run' and `set args', which pass arguments
7525 to inferior programs, now complete on file names, similar to what
7526 users expect at the shell prompt.
7528 Commands which accept locations, such as `disassemble', `print',
7529 `breakpoint', `until', etc. now complete on filenames as well as
7530 program symbols. Thus, if you type "break foob TAB", and the source
7531 files linked into the programs include `foobar.c', that file name will
7532 be one of the candidates for completion. However, file names are not
7533 considered for completion after you typed a colon that delimits a file
7534 name from a name of a function in that file, as in "break foo.c:bar".
7536 `set demangle-style' completes on available demangling styles.
7538 * New platform-independent commands:
7540 It is now possible to define a post-hook for a command as well as a
7541 hook that runs before the command. For more details, see the
7542 documentation of `hookpost' in the GDB manual.
7544 * Changes in GNU/Linux native debugging.
7546 Support for debugging multi-threaded programs has been completely
7547 revised for all platforms except m68k and sparc. You can now debug as
7548 many threads as your system allows you to have.
7550 Attach/detach is supported for multi-threaded programs.
7552 Support for SSE registers was added for x86. This doesn't work for
7553 multi-threaded programs though.
7555 * Changes in MIPS configurations.
7557 Multi-arch support is enabled for all MIPS configurations.
7559 GDB can now be built as native debugger on SGI Irix 6.x systems for
7560 debugging n32 executables. (Debugging 64-bit executables is not yet
7563 * Unified support for hardware watchpoints in all x86 configurations.
7565 Most (if not all) native x86 configurations support hardware-assisted
7566 breakpoints and watchpoints in a unified manner. This support
7567 implements debug register sharing between watchpoints, which allows to
7568 put a virtually infinite number of watchpoints on the same address,
7569 and also supports watching regions up to 16 bytes with several debug
7572 The new maintenance command `maintenance show-debug-regs' toggles
7573 debugging print-outs in functions that insert, remove, and test
7574 watchpoints and hardware breakpoints.
7576 * Changes in the DJGPP native configuration.
7578 New command ``info dos sysinfo'' displays assorted information about
7579 the CPU, OS, memory, and DPMI server.
7581 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
7582 display information about segment descriptors stored in GDT, LDT, and
7585 New commands ``info dos pde'' and ``info dos pte'' display entries
7586 from Page Directory and Page Tables (for now works with CWSDPMI only).
7587 New command ``info dos address-pte'' displays the Page Table entry for
7588 a given linear address.
7590 GDB can now pass command lines longer than 126 characters to the
7591 program being debugged (requires an update to the libdbg.a library
7592 which is part of the DJGPP development kit).
7594 DWARF2 debug info is now supported.
7596 It is now possible to `step' and `next' through calls to `longjmp'.
7598 * Changes in documentation.
7600 All GDB documentation was converted to GFDL, the GNU Free
7601 Documentation License.
7603 Tracepoints-related commands are now fully documented in the GDB
7606 TUI, the Text-mode User Interface, is now documented in the manual.
7608 Tracepoints-related commands are now fully documented in the GDB
7611 The "GDB Internals" manual now has an index. It also includes
7612 documentation of `ui_out' functions, GDB coding standards, x86
7613 hardware watchpoints, and memory region attributes.
7615 * GDB's version number moved to ``version.in''
7617 The Makefile variable VERSION has been replaced by the file
7618 ``version.in''. People creating GDB distributions should update the
7619 contents of this file.
7623 GUD support is now a standard part of the EMACS distribution.
7625 *** Changes in GDB 5.0:
7627 * Improved support for debugging FP programs on x86 targets
7629 Unified and much-improved support for debugging floating-point
7630 programs on all x86 targets. In particular, ``info float'' now
7631 displays the FP registers in the same format on all x86 targets, with
7632 greater level of detail.
7634 * Improvements and bugfixes in hardware-assisted watchpoints
7636 It is now possible to watch array elements, struct members, and
7637 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7638 on x86 targets no longer erroneously trigger when the address is
7641 * Improvements in the native DJGPP version of GDB
7643 The distribution now includes all the scripts and auxiliary files
7644 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7645 machines ``out of the box''.
7647 The DJGPP version can now debug programs that use signals. It is
7648 possible to catch signals that happened in the debuggee, deliver
7649 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7650 would kill the program being debugged.) Programs that hook hardware
7651 interrupts (keyboard, timer, etc.) can also be debugged.
7653 It is now possible to debug DJGPP programs that redirect their
7654 standard handles or switch them to raw (as opposed to cooked) mode, or
7655 even close them. The command ``run < foo > bar'' works as expected,
7656 and ``info terminal'' reports useful information about the debuggee's
7657 terminal, including raw/cooked mode, redirection, etc.
7659 The DJGPP version now uses termios functions for console I/O, which
7660 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7663 DOS-style file names with drive letters are now fully supported by
7666 It is now possible to debug DJGPP programs that switch their working
7667 directory. It is also possible to rerun the debuggee any number of
7668 times without restarting GDB; thus, you can use the same setup,
7669 breakpoints, etc. for many debugging sessions.
7671 * New native configurations
7673 ARM GNU/Linux arm*-*-linux*
7674 PowerPC GNU/Linux powerpc-*-linux*
7678 Motorola MCore mcore-*-*
7679 x86 VxWorks i[3456]86-*-vxworks*
7680 PowerPC VxWorks powerpc-*-vxworks*
7681 TI TMS320C80 tic80-*-*
7683 * OBSOLETE configurations
7685 Altos 3068 m68*-altos-*
7686 Convex c1-*-*, c2-*-*
7688 ARM RISCix arm-*-* (as host)
7691 Configurations that have been declared obsolete will be commented out,
7692 but the code will be left in place. If there is no activity to revive
7693 these configurations before the next release of GDB, the sources will
7694 be permanently REMOVED.
7696 * Gould support removed
7698 Support for the Gould PowerNode and NP1 has been removed.
7700 * New features for SVR4
7702 On SVR4 native platforms (such as Solaris), if you attach to a process
7703 without first loading a symbol file, GDB will now attempt to locate and
7704 load symbols from the running process's executable file.
7706 * Many C++ enhancements
7708 C++ support has been greatly improved. Overload resolution now works properly
7709 in almost all cases. RTTI support is on the way.
7711 * Remote targets can connect to a sub-program
7713 A popen(3) style serial-device has been added. This device starts a
7714 sub-process (such as a stand-alone simulator) and then communicates
7715 with that. The sub-program to run is specified using the syntax
7716 ``|<program> <args>'' vis:
7718 (gdb) set remotedebug 1
7719 (gdb) target extended-remote |mn10300-elf-sim program-args
7721 * MIPS 64 remote protocol
7723 A long standing bug in the mips64 remote protocol where by GDB
7724 expected certain 32 bit registers (ex SR) to be transfered as 32
7725 instead of 64 bits has been fixed.
7727 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7728 added to provide backward compatibility with older versions of GDB.
7730 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7732 The command ``set remotebinarydownload'' command has been replaced by
7733 ``set remote X-packet''. Other commands in ``set remote'' family
7734 include ``set remote P-packet''.
7736 * Breakpoint commands accept ranges.
7738 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7739 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7740 ``tracepoint passcount'' also accepts a range of tracepoints.
7742 * ``apropos'' command added.
7744 The ``apropos'' command searches through command names and
7745 documentation strings, printing out matches, making it much easier to
7746 try to find a command that does what you are looking for.
7750 A new machine oriented interface (MI) has been added to GDB. This
7751 interface is designed for debug environments running GDB as a separate
7752 process. This is part of the long term libGDB project. See the
7753 "GDB/MI" chapter of the GDB manual for further information. It can be
7754 enabled by configuring with:
7756 .../configure --enable-gdbmi
7758 *** Changes in GDB-4.18:
7760 * New native configurations
7762 HP-UX 10.20 hppa*-*-hpux10.20
7763 HP-UX 11.x hppa*-*-hpux11.0*
7764 M68K GNU/Linux m68*-*-linux*
7768 Fujitsu FR30 fr30-*-elf*
7769 Intel StrongARM strongarm-*-*
7770 Mitsubishi D30V d30v-*-*
7772 * OBSOLETE configurations
7774 Gould PowerNode, NP1 np1-*-*, pn-*-*
7776 Configurations that have been declared obsolete will be commented out,
7777 but the code will be left in place. If there is no activity to revive
7778 these configurations before the next release of GDB, the sources will
7779 be permanently REMOVED.
7783 As a compatibility experiment, GDB's source files buildsym.h and
7784 buildsym.c have been converted to pure standard C, no longer
7785 containing any K&R compatibility code. We believe that all systems in
7786 use today either come with a standard C compiler, or have a GCC port
7787 available. If this is not true, please report the affected
7788 configuration to bug-gdb@gnu.org immediately. See the README file for
7789 information about getting a standard C compiler if you don't have one
7794 GDB now uses readline 2.2.
7796 * set extension-language
7798 You can now control the mapping between filename extensions and source
7799 languages by using the `set extension-language' command. For instance,
7800 you can ask GDB to treat .c files as C++ by saying
7801 set extension-language .c c++
7802 The command `info extensions' lists all of the recognized extensions
7803 and their associated languages.
7805 * Setting processor type for PowerPC and RS/6000
7807 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7808 you can use the `set processor' command to specify what variant of the
7809 PowerPC family you are debugging. The command
7813 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7814 following PowerPC and RS6000 variants:
7816 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7817 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7819 403GC IBM PowerPC 403GC
7820 505 Motorola PowerPC 505
7821 860 Motorola PowerPC 860 or 850
7822 601 Motorola PowerPC 601
7823 602 Motorola PowerPC 602
7824 603 Motorola/IBM PowerPC 603 or 603e
7825 604 Motorola PowerPC 604 or 604e
7826 750 Motorola/IBM PowerPC 750 or 750
7828 At the moment, this command just tells GDB what to name the
7829 special-purpose processor registers. Since almost all the affected
7830 registers are inaccessible to user-level programs, this command is
7831 only useful for remote debugging in its present form.
7835 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7836 more extensive support for HP-UX. Added features include shared
7837 library support, kernel threads and hardware watchpoints for 11.00,
7838 support for HP's ANSI C and C++ compilers, and a compatibility mode
7839 for xdb and dbx commands.
7843 HP's donation includes the new concept of catchpoints, which is a
7844 generalization of the old catch command. On HP-UX, it is now possible
7845 to catch exec, fork, and vfork, as well as library loading.
7847 This means that the existing catch command has changed; its first
7848 argument now specifies the type of catch to be set up. See the
7849 output of "help catch" for a list of catchpoint types.
7851 * Debugging across forks
7853 On HP-UX, you can choose which process to debug when a fork() happens
7858 HP has donated a curses-based terminal user interface (TUI). To get
7859 it, build with --enable-tui. Although this can be enabled for any
7860 configuration, at present it only works for native HP debugging.
7862 * GDB remote protocol additions
7864 A new protocol packet 'X' that writes binary data is now available.
7865 Default behavior is to try 'X', then drop back to 'M' if the stub
7866 fails to respond. The settable variable `remotebinarydownload'
7867 allows explicit control over the use of 'X'.
7869 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7870 full 64-bit address. The command
7872 set remoteaddresssize 32
7874 can be used to revert to the old behaviour. For existing remote stubs
7875 the change should not be noticed, as the additional address information
7878 In order to assist in debugging stubs, you may use the maintenance
7879 command `packet' to send any text string to the stub. For instance,
7881 maint packet heythere
7883 sends the packet "$heythere#<checksum>". Note that it is very easy to
7884 disrupt a debugging session by sending the wrong packet at the wrong
7887 The compare-sections command allows you to compare section data on the
7888 target to what is in the executable file without uploading or
7889 downloading, by comparing CRC checksums.
7891 * Tracing can collect general expressions
7893 You may now collect general expressions at tracepoints. This requires
7894 further additions to the target-side stub; see tracepoint.c and
7895 doc/agentexpr.texi for further details.
7897 * mask-address variable for Mips
7899 For Mips targets, you may control the zeroing of the upper 32 bits of
7900 a 64-bit address by entering `set mask-address on'. This is mainly
7901 of interest to users of embedded R4xxx and R5xxx processors.
7903 * Higher serial baud rates
7905 GDB's serial code now allows you to specify baud rates 57600, 115200,
7906 230400, and 460800 baud. (Note that your host system may not be able
7907 to achieve all of these rates.)
7911 The i960 configuration now includes an initial implementation of a
7912 builtin simulator, contributed by Jim Wilson.
7915 *** Changes in GDB-4.17:
7917 * New native configurations
7919 Alpha GNU/Linux alpha*-*-linux*
7920 Unixware 2.x i[3456]86-unixware2*
7921 Irix 6.x mips*-sgi-irix6*
7922 PowerPC GNU/Linux powerpc-*-linux*
7923 PowerPC Solaris powerpcle-*-solaris*
7924 Sparc GNU/Linux sparc-*-linux*
7925 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7929 Argonaut Risc Chip (ARC) arc-*-*
7930 Hitachi H8/300S h8300*-*-*
7931 Matsushita MN10200 w/simulator mn10200-*-*
7932 Matsushita MN10300 w/simulator mn10300-*-*
7933 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7934 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7935 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7936 Mitsubishi D10V w/simulator d10v-*-*
7937 Mitsubishi M32R/D w/simulator m32r-*-elf*
7938 Tsqware Sparclet sparclet-*-*
7939 NEC V850 w/simulator v850-*-*
7941 * New debugging protocols
7943 ARM with RDI protocol arm*-*-*
7944 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7945 DDB and LSI variants of PMON protocol mips*-*-*
7946 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7947 PowerPC with SDS protocol powerpc{,le}-*-eabi
7948 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7952 All configurations can now understand and use the DWARF 2 debugging
7953 format. The choice is automatic, if the symbol file contains DWARF 2
7958 GDB now includes basic Java language support. This support is
7959 only useful with Java compilers that produce native machine code.
7961 * solib-absolute-prefix and solib-search-path
7963 For SunOS and SVR4 shared libraries, you may now set the prefix for
7964 loading absolute shared library symbol files, and the search path for
7965 locating non-absolute shared library symbol files.
7967 * Live range splitting
7969 GDB can now effectively debug code for which GCC has performed live
7970 range splitting as part of its optimization. See gdb/doc/LRS for
7971 more details on the expected format of the stabs information.
7975 GDB's support for the GNU Hurd, including thread debugging, has been
7976 updated to work with current versions of the Hurd.
7980 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7981 instruction set. ARM GDB automatically detects when Thumb
7982 instructions are in use, and adjusts disassembly and backtracing
7987 GDB's MIPS target configurations now handle the MIP16 16-bit
7992 GDB now includes support for overlays; if an executable has been
7993 linked such that multiple sections are based at the same address, GDB
7994 will decide which section to use for symbolic info. You can choose to
7995 control the decision manually, using overlay commands, or implement
7996 additional target-side support and use "overlay load-target" to bring
7997 in the overlay mapping. Do "help overlay" for more detail.
8001 The command "info symbol <address>" displays information about
8002 the symbol at the specified address.
8006 The standard remote protocol now includes an extension that allows
8007 asynchronous collection and display of trace data. This requires
8008 extensive support in the target-side debugging stub. Tracing mode
8009 includes a new interaction mode in GDB and new commands: see the
8010 file tracepoint.c for more details.
8014 Configurations for embedded MIPS now include a simulator contributed
8015 by Cygnus Solutions. The simulator supports the instruction sets
8016 of most MIPS variants.
8020 Sparc configurations may now include the ERC32 simulator contributed
8021 by the European Space Agency. The simulator is not built into
8022 Sparc targets by default; configure with --enable-sim to include it.
8026 For target configurations that may include multiple variants of a
8027 basic architecture (such as MIPS and SH), you may now set the
8028 architecture explicitly. "set arch" sets, "info arch" lists
8029 the possible architectures.
8031 *** Changes in GDB-4.16:
8033 * New native configurations
8035 Windows 95, x86 Windows NT i[345]86-*-cygwin32
8036 M68K NetBSD m68k-*-netbsd*
8037 PowerPC AIX 4.x powerpc-*-aix*
8038 PowerPC MacOS powerpc-*-macos*
8039 PowerPC Windows NT powerpcle-*-cygwin32
8040 RS/6000 AIX 4.x rs6000-*-aix4*
8044 ARM with RDP protocol arm-*-*
8045 I960 with MON960 i960-*-coff
8046 MIPS VxWorks mips*-*-vxworks*
8047 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
8048 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
8050 Matra Sparclet sparclet-*-*
8054 The powerpc-eabi configuration now includes the PSIM simulator,
8055 contributed by Andrew Cagney, with assistance from Mike Meissner.
8056 PSIM is a very elaborate model of the PowerPC, including not only
8057 basic instruction set execution, but also details of execution unit
8058 performance and I/O hardware. See sim/ppc/README for more details.
8062 GDB now works with Solaris 2.5.
8064 * Windows 95/NT native
8066 GDB will now work as a native debugger on Windows 95 and Windows NT.
8067 To build it from source, you must use the "gnu-win32" environment,
8068 which uses a DLL to emulate enough of Unix to run the GNU tools.
8069 Further information, binaries, and sources are available at
8070 ftp.cygnus.com, under pub/gnu-win32.
8072 * dont-repeat command
8074 If a user-defined command includes the command `dont-repeat', then the
8075 command will not be repeated if the user just types return. This is
8076 useful if the command is time-consuming to run, so that accidental
8077 extra keystrokes don't run the same command many times.
8079 * Send break instead of ^C
8081 The standard remote protocol now includes an option to send a break
8082 rather than a ^C to the target in order to interrupt it. By default,
8083 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
8085 * Remote protocol timeout
8087 The standard remote protocol includes a new variable `remotetimeout'
8088 that allows you to set the number of seconds before GDB gives up trying
8089 to read from the target. The default value is 2.
8091 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
8093 By default GDB will automatically keep track of objects as they are
8094 loaded and unloaded by the dynamic linker. By using the command `set
8095 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
8096 when shared library events occur, thus allowing you to set breakpoints
8097 in shared libraries which are explicitly loaded by the inferior.
8099 Note this feature does not work on hpux8. On hpux9 you must link
8100 /usr/lib/end.o into your program. This feature should work
8101 automatically on hpux10.
8103 * Irix 5.x hardware watchpoint support
8105 Irix 5 configurations now support the use of hardware watchpoints.
8107 * Mips protocol "SYN garbage limit"
8109 When debugging a Mips target using the `target mips' protocol, you
8110 may set the number of characters that GDB will ignore by setting
8111 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
8112 every character. The default value is 1050.
8114 * Recording and replaying remote debug sessions
8116 If you set `remotelogfile' to the name of a file, gdb will write to it
8117 a recording of a remote debug session. This recording may then be
8118 replayed back to gdb using "gdbreplay". See gdbserver/README for
8119 details. This is useful when you have a problem with GDB while doing
8120 remote debugging; you can make a recording of the session and send it
8121 to someone else, who can then recreate the problem.
8123 * Speedups for remote debugging
8125 GDB includes speedups for downloading and stepping MIPS systems using
8126 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
8127 and more efficient S-record downloading.
8129 * Memory use reductions and statistics collection
8131 GDB now uses less memory and reports statistics about memory usage.
8132 Try the `maint print statistics' command, for example.
8134 *** Changes in GDB-4.15:
8136 * Psymtabs for XCOFF
8138 The symbol reader for AIX GDB now uses partial symbol tables. This
8139 can greatly improve startup time, especially for large executables.
8141 * Remote targets use caching
8143 Remote targets now use a data cache to speed up communication with the
8144 remote side. The data cache could lead to incorrect results because
8145 it doesn't know about volatile variables, thus making it impossible to
8146 debug targets which use memory mapped I/O devices. `set remotecache
8147 off' turns the data cache off.
8149 * Remote targets may have threads
8151 The standard remote protocol now includes support for multiple threads
8152 in the target system, using new protocol commands 'H' and 'T'. See
8153 gdb/remote.c for details.
8157 If GDB is configured with `--enable-netrom', then it will include
8158 support for the NetROM ROM emulator from XLNT Designs. The NetROM
8159 acts as though it is a bank of ROM on the target board, but you can
8160 write into it over the network. GDB's support consists only of
8161 support for fast loading into the emulated ROM; to debug, you must use
8162 another protocol, such as standard remote protocol. The usual
8163 sequence is something like
8165 target nrom <netrom-hostname>
8167 target remote <netrom-hostname>:1235
8171 GDB now includes support for the Apple Macintosh, as a host only. It
8172 may be run as either an MPW tool or as a standalone application, and
8173 it can debug through the serial port. All the usual GDB commands are
8174 available, but to the target command, you must supply "serial" as the
8175 device type instead of "/dev/ttyXX". See mpw-README in the main
8176 directory for more information on how to build. The MPW configuration
8177 scripts */mpw-config.in support only a few targets, and only the
8178 mips-idt-ecoff target has been tested.
8182 GDB configuration now uses autoconf. This is not user-visible,
8183 but does simplify configuration and building.
8187 GDB now supports hpux10.
8189 *** Changes in GDB-4.14:
8191 * New native configurations
8193 x86 FreeBSD i[345]86-*-freebsd
8194 x86 NetBSD i[345]86-*-netbsd
8195 NS32k NetBSD ns32k-*-netbsd
8196 Sparc NetBSD sparc-*-netbsd
8200 A29K VxWorks a29k-*-vxworks
8201 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
8202 CPU32 EST-300 emulator m68*-*-est*
8203 PowerPC ELF powerpc-*-elf
8206 * Alpha OSF/1 support for procfs
8208 GDB now supports procfs under OSF/1-2.x and higher, which makes it
8209 possible to attach to running processes. As the mounting of the /proc
8210 filesystem is optional on the Alpha, GDB automatically determines
8211 the availability of /proc during startup. This can lead to problems
8212 if /proc is unmounted after GDB has been started.
8214 * Arguments to user-defined commands
8216 User commands may accept up to 10 arguments separated by whitespace.
8217 Arguments are accessed within the user command via $arg0..$arg9. A
8220 print $arg0 + $arg1 + $arg2
8222 To execute the command use:
8225 Defines the command "adder" which prints the sum of its three arguments.
8226 Note the arguments are text substitutions, so they may reference variables,
8227 use complex expressions, or even perform inferior function calls.
8229 * New `if' and `while' commands
8231 This makes it possible to write more sophisticated user-defined
8232 commands. Both commands take a single argument, which is the
8233 expression to evaluate, and must be followed by the commands to
8234 execute, one per line, if the expression is nonzero, the list being
8235 terminated by the word `end'. The `if' command list may include an
8236 `else' word, which causes the following commands to be executed only
8237 if the expression is zero.
8239 * Fortran source language mode
8241 GDB now includes partial support for Fortran 77. It will recognize
8242 Fortran programs and can evaluate a subset of Fortran expressions, but
8243 variables and functions may not be handled correctly. GDB will work
8244 with G77, but does not yet know much about symbols emitted by other
8247 * Better HPUX support
8249 Most debugging facilities now work on dynamic executables for HPPAs
8250 running hpux9 or later. You can attach to running dynamically linked
8251 processes, but by default the dynamic libraries will be read-only, so
8252 for instance you won't be able to put breakpoints in them. To change
8253 that behavior do the following before running the program:
8259 This will cause the libraries to be mapped private and read-write.
8260 To revert to the normal behavior, do this:
8266 You cannot set breakpoints or examine data in the library until after
8267 the library is loaded if the function/data symbols do not have
8270 GDB can now also read debug symbols produced by the HP C compiler on
8271 HPPAs (sorry, no C++, Fortran or 68k support).
8273 * Target byte order now dynamically selectable
8275 You can choose which byte order to use with a target system, via the
8276 commands "set endian big" and "set endian little", and you can see the
8277 current setting by using "show endian". You can also give the command
8278 "set endian auto", in which case GDB will use the byte order
8279 associated with the executable. Currently, only embedded MIPS
8280 configurations support dynamic selection of target byte order.
8282 * New DOS host serial code
8284 This version uses DPMI interrupts to handle buffered I/O, so you
8285 no longer need to run asynctsr when debugging boards connected to
8288 *** Changes in GDB-4.13:
8290 * New "complete" command
8292 This lists all the possible completions for the rest of the line, if it
8293 were to be given as a command itself. This is intended for use by emacs.
8295 * Trailing space optional in prompt
8297 "set prompt" no longer adds a space for you after the prompt you set. This
8298 allows you to set a prompt which ends in a space or one that does not.
8300 * Breakpoint hit counts
8302 "info break" now displays a count of the number of times the breakpoint
8303 has been hit. This is especially useful in conjunction with "ignore"; you
8304 can ignore a large number of breakpoint hits, look at the breakpoint info
8305 to see how many times the breakpoint was hit, then run again, ignoring one
8306 less than that number, and this will get you quickly to the last hit of
8309 * Ability to stop printing at NULL character
8311 "set print null-stop" will cause GDB to stop printing the characters of
8312 an array when the first NULL is encountered. This is useful when large
8313 arrays actually contain only short strings.
8315 * Shared library breakpoints
8317 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
8318 breakpoints in shared libraries before the executable is run.
8320 * Hardware watchpoints
8322 There is a new hardware breakpoint for the watch command for sparclite
8323 targets. See gdb/sparclite/hw_breakpoint.note.
8325 Hardware watchpoints are also now supported under GNU/Linux.
8329 Annotations have been added. These are for use with graphical interfaces,
8330 and are still experimental. Currently only gdba.el uses these.
8332 * Improved Irix 5 support
8334 GDB now works properly with Irix 5.2.
8336 * Improved HPPA support
8338 GDB now works properly with the latest GCC and GAS.
8340 * New native configurations
8342 Sequent PTX4 i[34]86-sequent-ptx4
8343 HPPA running OSF/1 hppa*-*-osf*
8344 Atari TT running SVR4 m68*-*-sysv4*
8345 RS/6000 LynxOS rs6000-*-lynxos*
8349 OS/9000 i[34]86-*-os9k
8350 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
8353 * Hitachi SH7000 and E7000-PC ICE support
8355 There is now support for communicating with the Hitachi E7000-PC ICE.
8356 This is available automatically when GDB is configured for the SH.
8360 As usual, a variety of small fixes and improvements, both generic
8361 and configuration-specific. See the ChangeLog for more detail.
8363 *** Changes in GDB-4.12:
8365 * Irix 5 is now supported
8369 GDB-4.12 on the HPPA has a number of changes which make it unable
8370 to debug the output from the currently released versions of GCC and
8371 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8372 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8373 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8376 *** Changes in GDB-4.11:
8378 * User visible changes:
8382 The "set remotedebug" option is now consistent between the mips remote
8383 target, remote targets using the gdb-specific protocol, UDI (AMD's
8384 debug protocol for the 29k) and the 88k bug monitor. It is now an
8385 integer specifying a debug level (normally 0 or 1, but 2 means more
8386 debugging info for the mips target).
8388 * DEC Alpha native support
8390 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8391 debug info, but GDB works fairly well with the DEC compiler and should
8392 work with a future GCC release. See the README file for a few
8393 Alpha-specific notes.
8395 * Preliminary thread implementation
8397 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8399 * LynxOS native and target support for 386
8401 This release has been hosted on LynxOS 2.2, and also can be configured
8402 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8405 * Improvements in C++ mangling/demangling.
8407 This release has much better g++ debugging, specifically in name
8408 mangling/demangling, virtual function calls, print virtual table,
8409 call methods, ...etc.
8411 *** Changes in GDB-4.10:
8413 * User visible changes:
8415 Remote debugging using the GDB-specific (`target remote') protocol now
8416 supports the `load' command. This is only useful if you have some
8417 other way of getting the stub to the target system, and you can put it
8418 somewhere in memory where it won't get clobbered by the download.
8420 Filename completion now works.
8422 When run under emacs mode, the "info line" command now causes the
8423 arrow to point to the line specified. Also, "info line" prints
8424 addresses in symbolic form (as well as hex).
8426 All vxworks based targets now support a user settable option, called
8427 vxworks-timeout. This option represents the number of seconds gdb
8428 should wait for responses to rpc's. You might want to use this if
8429 your vxworks target is, perhaps, a slow software simulator or happens
8430 to be on the far side of a thin network line.
8434 This release contains support for using a DEC alpha as a GDB host for
8435 cross debugging. Native alpha debugging is not supported yet.
8438 *** Changes in GDB-4.9:
8442 This is the first GDB release which is accompanied by a matching testsuite.
8443 The testsuite requires installation of dejagnu, which should be available
8444 via ftp from most sites that carry GNU software.
8448 'Cfront' style demangling has had its name changed to 'ARM' style, to
8449 emphasize that it was written from the specifications in the C++ Annotated
8450 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8451 disclaimers, it still generated too much confusion with users attempting to
8452 use gdb with AT&T cfront.
8456 GDB now uses a standard remote interface to a simulator library.
8457 So far, the library contains simulators for the Zilog Z8001/2, the
8458 Hitachi H8/300, H8/500 and Super-H.
8460 * New targets supported
8462 H8/300 simulator h8300-hitachi-hms or h8300hms
8463 H8/500 simulator h8500-hitachi-hms or h8500hms
8464 SH simulator sh-hitachi-hms or sh
8465 Z8000 simulator z8k-zilog-none or z8ksim
8466 IDT MIPS board over serial line mips-idt-ecoff
8468 Cross-debugging to GO32 targets is supported. It requires a custom
8469 version of the i386-stub.c module which is integrated with the
8470 GO32 memory extender.
8472 * New remote protocols
8474 MIPS remote debugging protocol.
8476 * New source languages supported
8478 This version includes preliminary support for Chill, a Pascal like language
8479 used by telecommunications companies. Chill support is also being integrated
8480 into the GNU compiler, but we don't know when it will be publically available.
8483 *** Changes in GDB-4.8:
8485 * HP Precision Architecture supported
8487 GDB now supports HP PA-RISC machines running HPUX. A preliminary
8488 version of this support was available as a set of patches from the
8489 University of Utah. GDB does not support debugging of programs
8490 compiled with the HP compiler, because HP will not document their file
8491 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
8492 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
8494 Many problems in the preliminary version have been fixed.
8496 * Faster and better demangling
8498 We have improved template demangling and fixed numerous bugs in the GNU style
8499 demangler. It can now handle type modifiers such as `static' or `const'. Wide
8500 character types (wchar_t) are now supported. Demangling of each symbol is now
8501 only done once, and is cached when the symbol table for a file is read in.
8502 This results in a small increase in memory usage for C programs, a moderate
8503 increase in memory usage for C++ programs, and a fantastic speedup in
8506 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
8507 from the specifications in the Annotated Reference Manual, which AT&T's
8508 compiler does not actually implement.
8510 * G++ multiple inheritance compiler problem
8512 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
8513 inheritance lattices was reworked to properly discover ambiguities. We
8514 recently found an example which causes this new algorithm to fail in a
8515 very subtle way, producing bad debug information for those classes.
8516 The file 'gcc.patch' (in this directory) can be applied to gcc to
8517 circumvent the problem. A future GCC release will contain a complete
8520 The previous G++ debug info problem (mentioned below for the gdb-4.7
8521 release) is fixed in gcc version 2.3.2.
8523 * Improved configure script
8525 The `configure' script will now attempt to guess your system type if
8526 you don't supply a host system type. The old scheme of supplying a
8527 host system triplet is preferable over using this. All the magic is
8528 done in the new `config.guess' script. Examine it for details.
8530 We have also brought our configure script much more in line with the FSF's
8531 version. It now supports the --with-xxx options. In particular,
8532 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
8533 The resulting GDB will not be able to read arbitrary object file formats --
8534 only the format ``expected'' to be used on the configured target system.
8535 We hope to make this the default in a future release.
8537 * Documentation improvements
8539 There's new internal documentation on how to modify GDB, and how to
8540 produce clean changes to the code. We implore people to read it
8541 before submitting changes.
8543 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
8544 M4 macros. The new texinfo.tex is provided in this release. Pre-built
8545 `info' files are also provided. To build `info' files from scratch,
8546 you will need the latest `makeinfo' release, which will be available in
8547 a future texinfo-X.Y release.
8549 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
8550 We're not sure exactly which versions have this problem, but it has
8551 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
8552 or better. If that isn't possible, there is a patch in
8553 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
8554 around this problem.
8558 GDB now supports array constants that can be used in expressions typed in by
8559 the user. The syntax is `{element, element, ...}'. Ie: you can now type
8560 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
8563 The new directory `gdb/sparclite' contains a program that demonstrates
8564 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
8566 * New native hosts supported
8568 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
8569 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
8571 * New targets supported
8573 AMD 29k family via UDI a29k-amd-udi or udi29k
8575 * New file formats supported
8577 BFD now supports reading HP/PA-RISC executables (SOM file format?),
8578 HPUX core files, and SCO 3.2v2 core files.
8582 Attaching to processes now works again; thanks for the many bug reports.
8584 We have also stomped on a bunch of core dumps caused by
8585 printf_filtered("%s") problems.
8587 We eliminated a copyright problem on the rpc and ptrace header files
8588 for VxWorks, which was discovered at the last minute during the 4.7
8589 release. You should now be able to build a VxWorks GDB.
8591 You can now interrupt gdb while an attached process is running. This
8592 will cause the attached process to stop, and give control back to GDB.
8594 We fixed problems caused by using too many file descriptors
8595 for reading symbols from object files and libraries. This was
8596 especially a problem for programs that used many (~100) shared
8599 The `step' command now only enters a subroutine if there is line number
8600 information for the subroutine. Otherwise it acts like the `next'
8601 command. Previously, `step' would enter subroutines if there was
8602 any debugging information about the routine. This avoids problems
8603 when using `cc -g1' on MIPS machines.
8605 * Internal improvements
8607 GDB's internal interfaces have been improved to make it easier to support
8608 debugging of multiple languages in the future.
8610 GDB now uses a common structure for symbol information internally.
8611 Minimal symbols (derived from linkage symbols in object files), partial
8612 symbols (from a quick scan of debug information), and full symbols
8613 contain a common subset of information, making it easier to write
8614 shared code that handles any of them.
8616 * New command line options
8618 We now accept --silent as an alias for --quiet.
8622 The memory-mapped-malloc library is now licensed under the GNU Library
8623 General Public License.
8625 *** Changes in GDB-4.7:
8627 * Host/native/target split
8629 GDB has had some major internal surgery to untangle the support for
8630 hosts and remote targets. Now, when you configure GDB for a remote
8631 target, it will no longer load in all of the support for debugging
8632 local programs on the host. When fully completed and tested, this will
8633 ensure that arbitrary host/target combinations are possible.
8635 The primary conceptual shift is to separate the non-portable code in
8636 GDB into three categories. Host specific code is required any time GDB
8637 is compiled on that host, regardless of the target. Target specific
8638 code relates to the peculiarities of the target, but can be compiled on
8639 any host. Native specific code is everything else: it can only be
8640 built when the host and target are the same system. Child process
8641 handling and core file support are two common `native' examples.
8643 GDB's use of /proc for controlling Unix child processes is now cleaner.
8644 It has been split out into a single module under the `target_ops' vector,
8645 plus two native-dependent functions for each system that uses /proc.
8647 * New hosts supported
8649 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8650 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8651 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8653 * New targets supported
8655 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8656 68030 and CPU32 m68030-*-*, m68332-*-*
8658 * New native hosts supported
8660 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8661 (386bsd is not well tested yet)
8662 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8664 * New file formats supported
8666 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8667 supports reading of `a.out.adobe' object files, which are an a.out
8668 format extended with minimal information about multiple sections.
8672 `show copying' is the same as the old `info copying'.
8673 `show warranty' is the same as `info warrantee'.
8674 These were renamed for consistency. The old commands continue to work.
8676 `info handle' is a new alias for `info signals'.
8678 You can now define pre-command hooks, which attach arbitrary command
8679 scripts to any command. The commands in the hook will be executed
8680 prior to the user's command. You can also create a hook which will be
8681 executed whenever the program stops. See gdb.texinfo.
8685 We now deal with Cfront style name mangling, and can even extract type
8686 info from mangled symbols. GDB can automatically figure out which
8687 symbol mangling style your C++ compiler uses.
8689 Calling of methods and virtual functions has been improved as well.
8693 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8694 fixed. This was due to mishandling of the extra N_SO stabs output
8697 We also finally got Ultrix 4.2 running in house, and fixed core file
8698 support, with help from a dozen people on the net.
8700 John M. Farrell discovered that the reason that single-stepping was so
8701 slow on all of the Mips based platforms (primarily SGI and DEC) was
8702 that we were trying to demangle and lookup a symbol used for internal
8703 purposes on every instruction that was being stepped through. Changing
8704 the name of that symbol so that it couldn't be mistaken for a C++
8705 mangled symbol sped things up a great deal.
8707 Rich Pixley sped up symbol lookups in general by getting much smarter
8708 about when C++ symbol mangling is necessary. This should make symbol
8709 completion (TAB on the command line) much faster. It's not as fast as
8710 we'd like, but it's significantly faster than gdb-4.6.
8714 A new user controllable variable 'call_scratch_address' can
8715 specify the location of a scratch area to be used when GDB
8716 calls a function in the target. This is necessary because the
8717 usual method of putting the scratch area on the stack does not work
8718 in systems that have separate instruction and data spaces.
8720 We integrated changes to support the 29k UDI (Universal Debugger
8721 Interface), but discovered at the last minute that we didn't have all
8722 of the appropriate copyright paperwork. We are working with AMD to
8723 resolve this, and hope to have it available soon.
8727 We have sped up the remote serial line protocol, especially for targets
8728 with lots of registers. It now supports a new `expedited status' ('T')
8729 message which can be used in place of the existing 'S' status message.
8730 This allows the remote stub to send only the registers that GDB
8731 needs to make a quick decision about single-stepping or conditional
8732 breakpoints, eliminating the need to fetch the entire register set for
8733 each instruction being stepped through.
8735 The GDB remote serial protocol now implements a write-through cache for
8736 registers, only re-reading the registers if the target has run.
8738 There is also a new remote serial stub for SPARC processors. You can
8739 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8740 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8741 processor with a serial port.
8745 Configure.in files have become much easier to read and modify. A new
8746 `table driven' format makes it more obvious what configurations are
8747 supported, and what files each one uses.
8751 There is a new opcodes library which will eventually contain all of the
8752 disassembly routines and opcode tables. At present, it only contains
8753 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8754 disassembler (binutils/objdump) to share these routines.
8756 The libiberty library is now copylefted under the GNU Library General
8757 Public License. This allows more liberal use, and was done so libg++
8758 can use it. This makes no difference to GDB, since the Library License
8759 grants all the rights from the General Public License.
8763 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8764 reference to the stabs symbol info used by the debugger. It is (as far
8765 as we know) the only published document on this fascinating topic. We
8766 encourage you to read it, compare it to the stabs information on your
8767 system, and send improvements on the document in general (to
8768 bug-gdb@prep.ai.mit.edu).
8770 And, of course, many bugs have been fixed.
8773 *** Changes in GDB-4.6:
8775 * Better support for C++ function names
8777 GDB now accepts as input the "demangled form" of C++ overloaded function
8778 names and member function names, and can do command completion on such names
8779 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8780 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8781 Make use of command completion, it is your friend.
8783 GDB also now accepts a variety of C++ mangled symbol formats. They are
8784 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8785 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8786 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8787 for the list of formats.
8789 * G++ symbol mangling problem
8791 Recent versions of gcc have a bug in how they emit debugging information for
8792 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8793 directory) can be applied to gcc to fix the problem. Alternatively, if you
8794 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8795 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8796 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8799 * New 'maintenance' command
8801 All of the commands related to hacking GDB internals have been moved out of
8802 the main command set, and now live behind the 'maintenance' command. This
8803 can also be abbreviated as 'mt'. The following changes were made:
8805 dump-me -> maintenance dump-me
8806 info all-breakpoints -> maintenance info breakpoints
8807 printmsyms -> maintenance print msyms
8808 printobjfiles -> maintenance print objfiles
8809 printpsyms -> maintenance print psymbols
8810 printsyms -> maintenance print symbols
8812 The following commands are new:
8814 maintenance demangle Call internal GDB demangler routine to
8815 demangle a C++ link name and prints the result.
8816 maintenance print type Print a type chain for a given symbol
8818 * Change to .gdbinit file processing
8820 We now read the $HOME/.gdbinit file before processing the argv arguments
8821 (e.g. reading symbol files or core files). This allows global parameters to
8822 be set, which will apply during the symbol reading. The ./.gdbinit is still
8823 read after argv processing.
8825 * New hosts supported
8827 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8829 GNU/Linux support i386-unknown-linux or linux
8831 We are also including code to support the HP/PA running BSD and HPUX. This
8832 is almost guaranteed not to work, as we didn't have time to test or build it
8833 for this release. We are including it so that the more adventurous (or
8834 masochistic) of you can play with it. We also had major problems with the
8835 fact that the compiler that we got from HP doesn't support the -g option.
8838 * New targets supported
8840 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8842 * More smarts about finding #include files
8844 GDB now remembers the compilation directory for all include files, and for
8845 all files from which C is generated (like yacc and lex sources). This
8846 greatly improves GDB's ability to find yacc/lex sources, and include files,
8847 especially if you are debugging your program from a directory different from
8848 the one that contains your sources.
8850 We also fixed a bug which caused difficulty with listing and setting
8851 breakpoints in include files which contain C code. (In the past, you had to
8852 try twice in order to list an include file that you hadn't looked at before.)
8854 * Interesting infernals change
8856 GDB now deals with arbitrary numbers of sections, where the symbols for each
8857 section must be relocated relative to that section's landing place in the
8858 target's address space. This work was needed to support ELF with embedded
8859 stabs used by Solaris-2.0.
8861 * Bug fixes (of course!)
8863 There have been loads of fixes for the following things:
8864 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8865 i960, stabs, DOS(GO32), procfs, etc...
8867 See the ChangeLog for details.
8869 *** Changes in GDB-4.5:
8871 * New machines supported (host and target)
8873 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8875 SGI Irix-4.x mips-sgi-irix4 or iris4
8877 * New malloc package
8879 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8880 Mmalloc is capable of handling multiple heaps of memory. It is also
8881 capable of saving a heap to a file, and then mapping it back in later.
8882 This can be used to greatly speedup the startup of GDB by using a
8883 pre-parsed symbol table which lives in a mmalloc managed heap. For
8884 more details, please read mmalloc/mmalloc.texi.
8888 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8889 'help info proc' for details.
8891 * MIPS ecoff symbol table format
8893 The code that reads MIPS symbol table format is now supported on all hosts.
8894 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8897 * File name changes for MS-DOS
8899 Many files in the config directories have been renamed to make it easier to
8900 support GDB on MS-DOSe systems (which have very restrictive file name
8901 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8902 environment) is close to working but has some remaining problems. Note
8903 that debugging of DOS programs is not supported, due to limitations
8904 in the ``operating system'', but it can be used to host cross-debugging.
8906 * Cross byte order fixes
8908 Many fixes have been made to support cross debugging of Sparc and MIPS
8909 targets from hosts whose byte order differs.
8911 * New -mapped and -readnow options
8913 If memory-mapped files are available on your system through the 'mmap'
8914 system call, you can use the -mapped option on the `file' or
8915 `symbol-file' commands to cause GDB to write the symbols from your
8916 program into a reusable file. If the program you are debugging is
8917 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8918 Future GDB debugging sessions will notice the presence of this file,
8919 and will quickly map in symbol information from it, rather than reading
8920 the symbol table from the executable program. Using the '-mapped'
8921 option in a GDB `file' or `symbol-file' command has the same effect as
8922 starting GDB with the '-mapped' command-line option.
8924 You can cause GDB to read the entire symbol table immediately by using
8925 the '-readnow' option with any of the commands that load symbol table
8926 information (or on the GDB command line). This makes the command
8927 slower, but makes future operations faster.
8929 The -mapped and -readnow options are typically combined in order to
8930 build a `fred.syms' file that contains complete symbol information.
8931 A simple GDB invocation to do nothing but build a `.syms' file for future
8934 gdb -batch -nx -mapped -readnow programname
8936 The `.syms' file is specific to the host machine on which GDB is run.
8937 It holds an exact image of GDB's internal symbol table. It cannot be
8938 shared across multiple host platforms.
8940 * longjmp() handling
8942 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8943 siglongjmp() without losing control. This feature has not yet been ported to
8944 all systems. It currently works on many 386 platforms, all MIPS-based
8945 platforms (SGI, DECstation, etc), and Sun3/4.
8949 Preliminary work has been put in to support the new Solaris OS from Sun. At
8950 this time, it can control and debug processes, but it is not capable of
8955 As always, many many bug fixes. The major areas were with g++, and mipsread.
8956 People using the MIPS-based platforms should experience fewer mysterious
8957 crashes and trashed symbol tables.
8959 *** Changes in GDB-4.4:
8961 * New machines supported (host and target)
8963 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8965 BSD Reno on Vax vax-dec-bsd
8966 Ultrix on Vax vax-dec-ultrix
8968 * New machines supported (target)
8970 AMD 29000 embedded, using EBMON a29k-none-none
8974 GDB continues to improve its handling of C++. `References' work better.
8975 The demangler has also been improved, and now deals with symbols mangled as
8976 per the Annotated C++ Reference Guide.
8978 GDB also now handles `stabs' symbol information embedded in MIPS
8979 `ecoff' symbol tables. Since the ecoff format was not easily
8980 extensible to handle new languages such as C++, this appeared to be a
8981 good way to put C++ debugging info into MIPS binaries. This option
8982 will be supported in the GNU C compiler, version 2, when it is
8985 * New features for SVR4
8987 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8988 shared libraries. Debugging dynamically linked programs should present
8989 only minor differences from debugging statically linked programs.
8991 The `info proc' command will print out information about any process
8992 on an SVR4 system (including the one you are debugging). At the moment,
8993 it prints the address mappings of the process.
8995 If you bring up GDB on another SVR4 system, please send mail to
8996 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8998 * Better dynamic linking support in SunOS
9000 Reading symbols from shared libraries which contain debugging symbols
9001 now works properly. However, there remain issues such as automatic
9002 skipping of `transfer vector' code during function calls, which
9003 make it harder to debug code in a shared library, than to debug the
9004 same code linked statically.
9008 GDB is now using the latest `getopt' routines from the FSF. This
9009 version accepts the -- prefix for options with long names. GDB will
9010 continue to accept the old forms (-option and +option) as well.
9011 Various single letter abbreviations for options have been explicity
9012 added to the option table so that they won't get overshadowed in the
9013 future by other options that begin with the same letter.
9017 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
9018 Many assorted bugs have been handled. Many more remain to be handled.
9019 See the various ChangeLog files (primarily in gdb and bfd) for details.
9022 *** Changes in GDB-4.3:
9024 * New machines supported (host and target)
9026 Amiga 3000 running Amix m68k-cbm-svr4 or amix
9027 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
9028 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
9030 * Almost SCO Unix support
9032 We had hoped to support:
9033 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
9034 (except for core file support), but we discovered very late in the release
9035 that it has problems with process groups that render gdb unusable. Sorry
9036 about that. I encourage people to fix it and post the fixes.
9038 * Preliminary ELF and DWARF support
9040 GDB can read ELF object files on System V Release 4, and can handle
9041 debugging records for C, in DWARF format, in ELF files. This support
9042 is preliminary. If you bring up GDB on another SVR4 system, please
9043 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
9048 GDB now uses the latest `readline' library. One user-visible change
9049 is that two tabs will list possible command completions, which previously
9050 required typing M-? (meta-question mark, or ESC ?).
9054 The `stepi' bug that many of you noticed has been squashed.
9055 Many bugs in C++ have been handled. Many more remain to be handled.
9056 See the various ChangeLog files (primarily in gdb and bfd) for details.
9058 * State of the MIPS world (in case you wondered):
9060 GDB can understand the symbol tables emitted by the compilers
9061 supplied by most vendors of MIPS-based machines, including DEC. These
9062 symbol tables are in a format that essentially nobody else uses.
9064 Some versions of gcc come with an assembler post-processor called
9065 mips-tfile. This program is required if you want to do source-level
9066 debugging of gcc-compiled programs. I believe FSF does not ship
9067 mips-tfile with gcc version 1, but it will eventually come with gcc
9070 Debugging of g++ output remains a problem. g++ version 1.xx does not
9071 really support it at all. (If you're lucky, you should be able to get
9072 line numbers and stack traces to work, but no parameters or local
9073 variables.) With some work it should be possible to improve the
9076 When gcc version 2 is released, you will have somewhat better luck.
9077 However, even then you will get confusing results for inheritance and
9080 We will eventually provide full debugging of g++ output on
9081 DECstations. This will probably involve some kind of stabs-in-ecoff
9082 encapulation, but the details have not been worked out yet.
9085 *** Changes in GDB-4.2:
9087 * Improved configuration
9089 Only one copy of `configure' exists now, and it is not self-modifying.
9090 Porting BFD is simpler.
9094 The `step' and `next' commands now only stop at the first instruction
9095 of a source line. This prevents the multiple stops that used to occur
9096 in switch statements, for-loops, etc. `Step' continues to stop if a
9097 function that has debugging information is called within the line.
9101 Lots of small bugs fixed. More remain.
9103 * New host supported (not target)
9105 Intel 386 PC clone running Mach i386-none-mach
9108 *** Changes in GDB-4.1:
9110 * Multiple source language support
9112 GDB now has internal scaffolding to handle several source languages.
9113 It determines the type of each source file from its filename extension,
9114 and will switch expression parsing and number formatting to match the
9115 language of the function in the currently selected stack frame.
9116 You can also specifically set the language to be used, with
9117 `set language c' or `set language modula-2'.
9121 GDB now has preliminary support for the GNU Modula-2 compiler,
9122 currently under development at the State University of New York at
9123 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
9124 continue through the fall of 1991 and into 1992.
9126 Other Modula-2 compilers are currently not supported, and attempting to
9127 debug programs compiled with them will likely result in an error as the
9128 symbol table is read. Feel free to work on it, though!
9130 There are hooks in GDB for strict type checking and range checking,
9131 in the `Modula-2 philosophy', but they do not currently work.
9135 GDB can now write to executable and core files (e.g. patch
9136 a variable's value). You must turn this switch on, specify
9137 the file ("exec foo" or "core foo"), *then* modify it, e.g.
9138 by assigning a new value to a variable. Modifications take
9141 * Automatic SunOS shared library reading
9143 When you run your program, GDB automatically determines where its
9144 shared libraries (if any) have been loaded, and reads their symbols.
9145 The `share' command is no longer needed. This also works when
9146 examining core files.
9150 You can specify the number of lines that the `list' command shows.
9153 * New machines supported (host and target)
9155 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
9156 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
9157 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
9159 * New hosts supported (not targets)
9161 IBM RT/PC: romp-ibm-aix or rtpc
9163 * New targets supported (not hosts)
9165 AMD 29000 embedded with COFF a29k-none-coff
9166 AMD 29000 embedded with a.out a29k-none-aout
9167 Ultracomputer remote kernel debug a29k-nyu-kern
9169 * New remote interfaces
9175 *** Changes in GDB-4.0:
9179 Wide output is wrapped at good places to make the output more readable.
9181 Gdb now supports cross-debugging from a host machine of one type to a
9182 target machine of another type. Communication with the target system
9183 is over serial lines. The ``target'' command handles connecting to the
9184 remote system; the ``load'' command will download a program into the
9185 remote system. Serial stubs for the m68k and i386 are provided. Gdb
9186 also supports debugging of realtime processes running under VxWorks,
9187 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
9188 stub on the target system.
9190 New CPUs supported include the AMD 29000 and Intel 960.
9192 GDB now reads object files and symbol tables via a ``binary file''
9193 library, which allows a single copy of GDB to debug programs of multiple
9194 object file types such as a.out and coff.
9196 There is now a GDB reference card in "doc/refcard.tex". (Make targets
9197 refcard.dvi and refcard.ps are available to format it).
9200 * Control-Variable user interface simplified
9202 All variables that control the operation of the debugger can be set
9203 by the ``set'' command, and displayed by the ``show'' command.
9205 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
9206 ``Show prompt'' produces the response:
9207 Gdb's prompt is new-gdb=>.
9209 What follows are the NEW set commands. The command ``help set'' will
9210 print a complete list of old and new set commands. ``help set FOO''
9211 will give a longer description of the variable FOO. ``show'' will show
9212 all of the variable descriptions and their current settings.
9214 confirm on/off: Enables warning questions for operations that are
9215 hard to recover from, e.g. rerunning the program while
9216 it is already running. Default is ON.
9218 editing on/off: Enables EMACS style command line editing
9219 of input. Previous lines can be recalled with
9220 control-P, the current line can be edited with control-B,
9221 you can search for commands with control-R, etc.
9224 history filename NAME: NAME is where the gdb command history
9225 will be stored. The default is .gdb_history,
9226 or the value of the environment variable
9229 history size N: The size, in commands, of the command history. The
9230 default is 256, or the value of the environment variable
9233 history save on/off: If this value is set to ON, the history file will
9234 be saved after exiting gdb. If set to OFF, the
9235 file will not be saved. The default is OFF.
9237 history expansion on/off: If this value is set to ON, then csh-like
9238 history expansion will be performed on
9239 command line input. The default is OFF.
9241 radix N: Sets the default radix for input and output. It can be set
9242 to 8, 10, or 16. Note that the argument to "radix" is interpreted
9243 in the current radix, so "set radix 10" is always a no-op.
9245 height N: This integer value is the number of lines on a page. Default
9246 is 24, the current `stty rows'' setting, or the ``li#''
9247 setting from the termcap entry matching the environment
9250 width N: This integer value is the number of characters on a line.
9251 Default is 80, the current `stty cols'' setting, or the ``co#''
9252 setting from the termcap entry matching the environment
9255 Note: ``set screensize'' is obsolete. Use ``set height'' and
9256 ``set width'' instead.
9258 print address on/off: Print memory addresses in various command displays,
9259 such as stack traces and structure values. Gdb looks
9260 more ``symbolic'' if you turn this off; it looks more
9261 ``machine level'' with it on. Default is ON.
9263 print array on/off: Prettyprint arrays. New convenient format! Default
9266 print demangle on/off: Print C++ symbols in "source" form if on,
9269 print asm-demangle on/off: Same, for assembler level printouts
9272 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
9275 * Support for Epoch Environment.
9277 The epoch environment is a version of Emacs v18 with windowing. One
9278 new command, ``inspect'', is identical to ``print'', except that if you
9279 are running in the epoch environment, the value is printed in its own
9283 * Support for Shared Libraries
9285 GDB can now debug programs and core files that use SunOS shared libraries.
9286 Symbols from a shared library cannot be referenced
9287 before the shared library has been linked with the program (this
9288 happens after you type ``run'' and before the function main() is entered).
9289 At any time after this linking (including when examining core files
9290 from dynamically linked programs), gdb reads the symbols from each
9291 shared library when you type the ``sharedlibrary'' command.
9292 It can be abbreviated ``share''.
9294 sharedlibrary REGEXP: Load shared object library symbols for files
9295 matching a unix regular expression. No argument
9296 indicates to load symbols for all shared libraries.
9298 info sharedlibrary: Status of loaded shared libraries.
9303 A watchpoint stops execution of a program whenever the value of an
9304 expression changes. Checking for this slows down execution
9305 tremendously whenever you are in the scope of the expression, but is
9306 quite useful for catching tough ``bit-spreader'' or pointer misuse
9307 problems. Some machines such as the 386 have hardware for doing this
9308 more quickly, and future versions of gdb will use this hardware.
9310 watch EXP: Set a watchpoint (breakpoint) for an expression.
9312 info watchpoints: Information about your watchpoints.
9314 delete N: Deletes watchpoint number N (same as breakpoints).
9315 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
9316 enable N: Re-enables watchpoint number N (same as breakpoints).
9319 * C++ multiple inheritance
9321 When used with a GCC version 2 compiler, GDB supports multiple inheritance
9324 * C++ exception handling
9326 Gdb now supports limited C++ exception handling. Besides the existing
9327 ability to breakpoint on an exception handler, gdb can breakpoint on
9328 the raising of an exception (before the stack is peeled back to the
9331 catch FOO: If there is a FOO exception handler in the dynamic scope,
9332 set a breakpoint to catch exceptions which may be raised there.
9333 Multiple exceptions (``catch foo bar baz'') may be caught.
9335 info catch: Lists all exceptions which may be caught in the
9336 current stack frame.
9339 * Minor command changes
9341 The command ``call func (arg, arg, ...)'' now acts like the print
9342 command, except it does not print or save a value if the function's result
9343 is void. This is similar to dbx usage.
9345 The ``up'' and ``down'' commands now always print the frame they end up
9346 at; ``up-silently'' and `down-silently'' can be used in scripts to change
9347 frames without printing.
9349 * New directory command
9351 'dir' now adds directories to the FRONT of the source search path.
9352 The path starts off empty. Source files that contain debug information
9353 about the directory in which they were compiled can be found even
9354 with an empty path; Sun CC and GCC include this information. If GDB can't
9355 find your source file in the current directory, type "dir .".
9357 * Configuring GDB for compilation
9359 For normal use, type ``./configure host''. See README or gdb.texinfo
9362 GDB now handles cross debugging. If you are remotely debugging between
9363 two different machines, type ``./configure host -target=targ''.
9364 Host is the machine where GDB will run; targ is the machine
9365 where the program that you are debugging will run.