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.
28 GDB now generates sparse core files, on systems that support it.
30 maintenance info line-table
31 Add an EPILOGUE-BEGIN column to the output of the command. It indicates
32 if the line is considered the start of the epilgoue, and thus a point at
33 which the frame can be considered destroyed.
35 set unwindonsignal on|off
37 These commands are now aliases for the new set/show unwind-on-signal.
40 This command now gives an error if any unexpected arguments are
41 found after the command.
45 info missing-debug-handler
46 List all the registered missing debug handlers.
48 enable missing-debug-handler LOCUS HANDLER
49 disable missing-debug-handler LOCUS HANDLER
50 Enable or disable a missing debug handler with a name matching the
51 regular expression HANDLER, in LOCUS.
53 LOCUS can be 'global' to operate on global missing debug handler,
54 'progspace' to operate on handlers within the current program space,
55 or can be a regular expression which is matched against the filename
56 of the primary executable in each program space.
58 maintenance info linux-lwps
59 List all LWPs under control of the linux-nat target.
61 set remote thread-options-packet
62 show remote thread-options-packet
63 Set/show the use of the thread options packet.
65 set direct-call-timeout SECONDS
66 show direct-call-timeout
67 set indirect-call-timeout SECONDS
68 show indirect-call-timeout
69 These new settings can be used to limit how long GDB will wait for
70 an inferior function call to complete. The direct timeout is used
71 for inferior function calls from e.g. 'call' and 'print' commands,
72 while the indirect timeout is used for inferior function calls from
73 within a conditional breakpoint expression.
75 The default for the direct timeout is unlimited, while the default
76 for the indirect timeout is 30 seconds.
78 These timeouts will only have an effect for targets that are
79 operating in async mode. For non-async targets the timeouts are
80 ignored, GDB will wait indefinitely for an inferior function to
81 complete, unless interrupted by the user using Ctrl-C.
83 set unwind-on-timeout on|off
84 show unwind-on-timeout
85 These commands control whether GDB should unwind the stack when a
86 timeout occurs during an inferior function call. The default is
87 off, in which case the inferior will remain in the frame where the
88 timeout occurred. When on, GDB will unwind the stack removing the
89 dummy frame that was added for the inferior call, and restoring the
90 inferior state to how it was before the inferior call started.
92 set unwind-on-signal on|off
94 These new commands replaces the existing set/show unwindonsignal. The
95 old command is maintained as an alias.
97 * New features in the GDB remote stub, GDBserver
99 ** The --remote-debug and --event-loop-debug command line options
102 ** The --debug command line option now takes an optional comma
103 separated list of components to emit debug for. The currently
104 supported components are: all, threads, event-loop, and remote.
105 If no components are given then threads is assumed.
107 ** The 'monitor set remote-debug' and 'monitor set event-loop-debug'
108 command have been removed.
110 ** The 'monitor set debug 0|1' command has been extended to take a
111 component name, e.g.: 'monitor set debug COMPONENT off|on'.
112 Possible component names are: all, threads, event-loop, and
117 ** New function gdb.notify_mi(NAME, DATA), that emits custom
118 GDB/MI async notification.
120 ** New read/write attribute gdb.Value.bytes that contains a bytes
121 object holding the contents of this value.
123 ** New module gdb.missing_debug that facilitates dealing with
124 objfiles that are missing any debug information.
126 ** New function gdb.missing_debug.register_handler that can register
127 an instance of a sub-class of gdb.missing_debug.MissingDebugInfo
128 as a handler for objfiles that are missing debug information.
130 ** New class gdb.missing_debug.MissingDebugInfo which can be
131 sub-classed to create handlers for objfiles with missing debug
134 ** Stop events now have a "details" attribute that holds a
135 dictionary that carries the same information as an MI "*stopped"
138 ** New function gdb.interrupt(), that interrupts GDB as if the user
141 ** New gdb.InferiorThread.ptid_string attribute. This read-only
142 attribute contains the string that appears in the 'Target Id'
143 column of the 'info threads' command output.
145 ** It is no longer possible to create new gdb.Progspace object using
146 'gdb.Progspace()', this will result in a TypeError. Progspace
147 objects can still be obtained through calling other API
148 functions, for example 'gdb.current_progspace()'.
150 ** User defined attributes can be added to a gdb.Inferior object,
151 these will be stored in the object's new Inferior.__dict__
154 ** User defined attributes can be added to a gdb.InferiorThread
155 object, these will be stored in the object's new
156 InferiorThread.__dict__ attribute.
158 ** New constants gdb.SYMBOL_TYPE_DOMAIN, gdb.SYMBOL_FUNCTION_DOMAIN,
159 and gdb.SEARCH_*_DOMAIN corresponding to all the existing symbol
160 domains. Symbol lookup can now search in multiple domains at
161 once, and can also narrowly search for just a type or function.
163 * Debugger Adapter Protocol changes
165 ** GDB now emits the "process" event.
167 ** GDB now supports the "cancel" request.
169 ** The "attach" request now supports specifying the program.
171 ** New command "set debug dap-log-level" controls DAP logging.
173 ** The "set debug dap-log-file" command is now documented. This
174 command was available in GDB 14 but not documented.
178 ** New constants SYMBOL_TYPE_DOMAIN, SYMBOL_FUNCTION_DOMAIN, and
179 SEARCH_*_DOMAIN corresponding to all the existing symbol domains.
180 Symbol lookup can now search in multiple domains at once, and can
181 also narrowly search for just a type or function.
185 New stop reason: clone
186 Indicates that a clone system call was executed.
189 Enable/disable optional event reporting, on a per-thread basis.
190 Currently supported options are GDB_THREAD_OPTION_CLONE, to enable
191 clone event reporting, and GDB_THREAD_OPTION_EXIT to enable thread
192 exit event reporting.
194 QThreadOptions in qSupported
195 The qSupported packet allows GDB to inform the stub it supports the
196 QThreadOptions packet, and the qSupported response can contain the
197 set of thread options the remote stub supports.
200 This new packet allows GDB to query the stub about a given address to check
201 if it is tagged or not. Many memory tagging-related GDB commands need to
202 perform this check before they read/write the allocation tag related to an
203 address. Currently, however, this is done through a 'vFile' request to read
204 the file /proc/<PID>/smaps and check if the address is in a region reported
205 as memory tagged. Since not all targets have a notion of what the smaps
206 file is about, this new packet provides a more generic way to perform such
209 *** Changes in GDB 14
211 * GDB now supports the AArch64 Scalable Matrix Extension 2 (SME2), which
212 includes a new 512 bit lookup table register named ZT0.
214 * GDB now supports the AArch64 Scalable Matrix Extension (SME), which includes
215 a new matrix register named ZA, a new thread register TPIDR2 and a new vector
216 length register SVG (streaming vector granule). GDB also supports tracking
217 ZA state across signal frames.
219 Some features are still under development or are dependent on ABI specs that
220 are still in alpha stage. For example, manual function calls with ZA state
221 don't have any special handling, and tracking of SVG changes based on
222 DWARF information is still not implemented, but there are plans to do so in
225 * GDB now recognizes the NO_COLOR environment variable and disables
226 styling according to the spec. See https://no-color.org/.
227 Styling can be re-enabled with "set style enabled on".
229 * The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
230 has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
233 * GDB now has some support for integer types larger than 64 bits.
235 * Removed targets and native configurations
237 GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
238 AIX version is now AIX 7.1.
240 * Multi-target feature configuration
242 GDB now supports the individual configuration of remote targets' feature
243 sets. Based on the current selection of a target, the commands 'set remote
244 <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
245 configure a target's feature packet and to display its configuration,
248 The individual packet sizes can be configured and shown using the commands
249 ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
250 ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
251 ** 'show remote memory-read-packet-size'
252 ** 'show remote memory-write-packet-size'.
254 The configuration of the packet itself, as well as the size of a memory-read
255 or memory-write packet applies to the currently selected target (if
256 available). If no target is selected, it applies to future remote
257 connections. Similarly, the show commands print the configuration of the
258 currently selected target. If no remote target is selected, the default
259 configuration for future connections is shown.
261 * GDB has initial built-in support for the Debugger Adapter Protocol.
262 This support requires that GDB be built with Python scripting
265 * For the break command, multiple uses of the 'thread' or 'task'
266 keywords will now give an error instead of just using the thread or
267 task id from the last instance of the keyword. E.g.:
268 break foo thread 1 thread 2
269 will now give an error rather than using 'thread 2'.
271 * For the watch command, multiple uses of the 'task' keyword will now
272 give an error instead of just using the task id from the last
273 instance of the keyword. E.g.:
274 watch my_var task 1 task 2
275 will now give an error rather than using 'task 2'. The 'thread'
276 keyword already gave an error when used multiple times with the
277 watch command, this remains unchanged.
279 * The 'set print elements' setting now helps when printing large arrays.
280 If an array would otherwise exceed max-value-size, but 'print elements'
281 is set such that the size of elements to print is less than or equal
282 to 'max-value-size', GDB will now still print the array, however only
283 'max-value-size' worth of data will be added into the value history.
285 * For both the break and watch commands, it is now invalid to use both
286 the 'thread' and 'task' keywords within the same command. For
287 example the following commnds will now give an error:
288 break foo thread 1 task 1
289 watch var thread 2 task 3
291 * The printf command now accepts a '%V' output format which will
292 format an expression just as the 'print' command would. Print
293 options can be placed withing '[...]' after the '%V' to modify how
294 the value is printed. E.g:
295 printf "%V", some_array
296 printf "%V[-array-indexes on]", some_array
297 will print the array without, or with array indexes included, just
298 as the array would be printed by the 'print' command. This
299 functionality is also available for dprintf when dprintf-style is
302 * When the printf command requires a string to be fetched from the
303 inferior, GDB now uses the existing 'max-value-size' setting to the
304 limit the memory allocated within GDB. The default 'max-value-size'
305 is 64k. To print longer strings you should increase
308 * The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
310 * The Ada 2022 target name symbol ('@') is now supported by the Ada
313 * The 'list' command now accepts '.' as an argument, which tells GDB to
314 print the location around the point of execution within the current frame.
315 If the inferior hasn't started yet, the command will print around the
316 beginning of the 'main' function.
318 * Using the 'list' command with no arguments in a situation where the
319 command would attempt to list past the end of the file now warns the
320 user that the end of file has been reached, refers the user to the
321 newly added '.' argument
323 * Breakpoints can now be inferior-specific. This is similar to the
324 existing thread-specific breakpoint support. Breakpoint conditions
325 can include the 'inferior' keyword followed by an inferior id (as
326 displayed in the 'info inferiors' output). It is invalid to use the
327 'inferior' keyword with either the 'thread' or 'task' keywords when
328 creating a breakpoint.
330 * New convenience function "$_shell", to execute a shell command and
331 return the result. This lets you run shell commands in expressions.
334 (gdb) p $_shell("true")
336 (gdb) p $_shell("false")
338 (gdb) break func if $_shell("some command") == 0
342 --additional-debug-dirs=PATHs
344 Provide a colon-separated list of additional directories to search for
345 separate debug info. These directories are added to the default value of
346 the 'debug-file-directory' GDB parameter.
350 set debug breakpoint on|off
351 show debug breakpoint
352 Print additional debug messages about breakpoint insertion and removal.
354 maintenance print record-instruction [ N ]
355 Print the recorded information for a given instruction. If N is not given
356 prints how GDB would undo the last instruction executed. If N is negative,
357 prints how GDB would undo the N-th previous instruction, and if N is
358 positive, it prints how GDB will redo the N-th following instruction.
360 maintenance info frame-unwinders
361 List the frame unwinders currently in effect, starting with the highest
364 maintenance wait-for-index-cache
365 Wait until all pending writes to the index cache have completed.
367 set always-read-ctf on|off
369 When off, CTF is only read if DWARF is not present. When on, CTF is
370 read regardless of whether DWARF is present. Off by default.
373 Get main symbol to identify entry point into program.
375 set tui mouse-events [on|off]
376 show tui mouse-events
377 When on (default), mouse clicks control the TUI and can be accessed by
378 Python extensions. When off, mouse clicks are handled by the terminal,
379 enabling terminal-native text selection.
383 ** MI version 1 has been removed.
385 ** mi now reports 'no-history' as a stop reason when hitting the end of the
386 reverse execution history.
388 ** When creating a thread-specific breakpoint using the '-p' option,
389 the -break-insert command would report the 'thread' field twice in
390 the reply. The content of both fields was always identical. This
391 has now been fixed; the 'thread' field will be reported just once
392 for thread-specific breakpoints, or not at all for breakpoints
393 without a thread restriction. The same is also true for the 'task'
394 field of an Ada task-specific breakpoint.
396 ** It is no longer possible to create a thread-specific breakpoint for
397 a thread that doesn't exist using '-break-insert -p ID'. Creating
398 breakpoints for non-existent threads is not allowed when using the
399 CLI, that the MI allowed it was a long standing bug, which has now
402 ** The '--simple-values' argument to the '-stack-list-arguments',
403 '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
404 commands now takes reference types into account: that is, a value is now
405 considered simple if it is neither an array, structure, or union, nor a
406 reference to an array, structure, or union. (Previously all references were
407 considered simple.) Support for this feature can be verified by using the
408 '-list-features' command, which should contain "simple-values-ref-types".
410 ** The -break-insert command now accepts a '-g thread-group-id' option
411 to allow for the creation of inferior-specific breakpoints.
413 ** The bkpt tuple, which appears in breakpoint-created notifications,
414 and in the result of the -break-insert command can now include an
415 optional 'inferior' field for both the main breakpoint, and each
416 location, when the breakpoint is inferior-specific.
420 ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
422 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
424 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
425 now be of type 'str' otherwise a TypeError will be raised.
427 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
428 values of type 'bool'. Changing this attribute will now
429 invalidate GDB's frame-cache, which means GDB will need to
430 rebuild its frame-cache when next required - either with, or
431 without the particular unwinder, depending on how 'enabled' was
434 ** New methods added to the gdb.PendingFrame class. These methods
435 have the same behaviour as the corresponding methods on
436 gdb.Frame. The new methods are:
438 - gdb.PendingFrame.name: Return the name for the frame's
440 - gdb.PendingFrame.is_valid: Return True if the pending frame
442 - gdb.PendingFrame.pc: Return the $pc register value for this
444 - gdb.PendingFrame.language: Return a string containing the
445 language for this frame, or None.
446 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
447 object for the current location within the pending frame, or
449 - gdb.PendingFrame.block: Return a gdb.Block for the current
450 pending frame, or None.
451 - gdb.PendingFrame.function: Return a gdb.Symbol for the
452 current pending frame, or None.
454 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
455 now use either an integer or a gdb.Value object for each of its
456 'sp', 'pc', and 'special' attributes.
458 ** A new class gdb.unwinder.FrameId has been added. Instances of
459 this class are constructed with 'sp' (stack-pointer) and 'pc'
460 (program-counter) values, and can be used as the frame-id when
461 calling gdb.PendingFrame.create_unwind_info.
463 ** It is now no longer possible to sub-class the
464 gdb.disassembler.DisassemblerResult type.
466 ** The Disassembler API from the gdb.disassembler module has been
467 extended to include styling support:
469 - The DisassemblerResult class can now be initialized with a list
470 of parts. Each part represents part of the disassembled
471 instruction along with the associated style information. This
472 list of parts can be accessed with the new
473 DisassemblerResult.parts property.
475 - New constants gdb.disassembler.STYLE_* representing all the
476 different styles part of an instruction might have.
478 - New methods DisassembleInfo.text_part and
479 DisassembleInfo.address_part which are used to create the new
480 styled parts of a disassembled instruction.
482 - Changes are backwards compatible, the older API can still be
483 used to disassemble instructions without styling.
485 ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
486 GDB/MI command and returns the output as a Python dictionary.
488 ** New function gdb.block_signals(). This returns a context manager
489 that blocks any signals that GDB needs to handle itself.
491 ** New class gdb.Thread. This is a subclass of threading.Thread
492 that calls gdb.block_signals in its "start" method.
494 ** gdb.parse_and_eval now has a new "global_context" parameter.
495 This can be used to request that the parse only examine global
498 ** gdb.Inferior now has a new "arguments" attribute. This holds the
499 command-line arguments to the inferior, if known.
501 ** gdb.Inferior now has a new "main_name" attribute. This holds the
502 name of the inferior's "main", if known.
504 ** gdb.Inferior now has new methods "clear_env", "set_env", and
505 "unset_env". These can be used to modify the inferior's
506 environment before it is started.
508 ** gdb.Value now has the 'assign' method.
510 ** gdb.Value now has the 'to_array' method. This converts an
511 array-like Value to an array.
513 ** gdb.Progspace now has the new method "objfile_for_address". This
514 returns the gdb.Objfile, if any, that covers a given address.
516 ** gdb.Breakpoint now has an "inferior" attribute. If the
517 Breakpoint object is inferior specific then this attribute holds
518 the inferior-id (an integer). If the Breakpoint object is not
519 inferior specific, then this field contains None. This field can
522 ** gdb.Type now has the "is_array_like" and "is_string_like"
523 methods. These reflect GDB's internal idea of whether a type
524 might be array- or string-like, even if they do not have the
525 corresponding type code.
527 ** gdb.ValuePrinter is a new class that can be used as the base
528 class for the result of applying a pretty-printer. As a base
529 class, it signals to gdb that the printer may implement new
530 pretty-printer methods.
532 ** New attribute Progspace.symbol_file. This attribute holds the
533 gdb.Objfile that corresponds to Progspace.filename (when
534 Progspace.filename is not None), otherwise, this attribute is
537 ** New attribute Progspace.executable_filename. This attribute
538 holds a string containing a file name set by the "exec-file" or
539 "file" commands, or None if no executable file is set. This
540 isn't the exact string passed by the user to these commands; the
541 file name will have been partially resolved to an absolute file
544 ** A new executable_changed event registry is available. This event
545 emits ExecutableChangedEvent objects, which have 'progspace' (a
546 gdb.Progspace) and 'reload' (a Boolean) attributes. This event
547 is emitted when gdb.Progspace.executable_filename changes.
549 ** New event registries gdb.events.new_progspace and
550 gdb.events.free_progspace, these emit NewProgspaceEvent and
551 FreeProgspaceEvent event types respectively. Both of these event
552 types have a single 'progspace' attribute, which is the
553 gdb.Progspace that is either being added to GDB, or removed from
556 ** gdb.LazyString now implements the __str__ method.
558 ** New method gdb.Frame.static_link that returns the outer frame
559 of a nested function frame.
561 *** Changes in GDB 13
563 * MI version 1 is deprecated, and will be removed in GDB 14.
565 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
566 reading memory tag data for AArch64 MTE from core files generated by
567 the gcore command or the Linux kernel.
569 When a process uses memory-mapped pages protected by memory tags (for
570 example, AArch64 MTE), this additional information will be recorded in
571 the core file in the event of a crash or if GDB generates a core file
572 from the current process state. GDB will show this additional information
573 automatically, or through one of the memory-tag subcommands.
575 * Scheduler-locking and new threads
577 When scheduler-locking is in effect, only the current thread may run
578 when the inferior is resumed. However, previously, new threads
579 created by the resumed thread would still be able to run free. Now,
580 they are held stopped.
582 * "info breakpoints" now displays enabled breakpoint locations of
583 disabled breakpoints as in the "y-" state. For example:
585 (gdb) info breakpoints
586 Num Type Disp Enb Address What
587 1 breakpoint keep n <MULTIPLE>
588 1.1 y- 0x00000000000011b6 in ...
589 1.2 y- 0x00000000000011c2 in ...
590 1.3 n 0x00000000000011ce in ...
592 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
593 aarch64 architectures.
595 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
597 * Remove support for building against Python 2, it is now only possible to
598 build GDB against Python 3.
600 * DBX mode has been removed.
602 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
603 emit to indicate where a breakpoint should be placed to break in a function
606 * Completion now also offers "NUMBER" for "set" commands that accept
607 a numeric argument and the "unlimited" keyword. For example:
609 (gdb) set width <TAB>
614 (gdb) complete set width
618 * Disassembler styling using libopcodes. GDB now supports
619 disassembler styling using libopcodes. This is only available for
620 some targets (currently x86 and RISC-V). For unsupported targets
621 Python Pygments is still used. For supported targets, libopcodes
622 styling is used by default.
624 * The Windows native target now supports target async.
626 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
628 * The format of 'disassemble /r' and 'record instruction-history /r'
629 has changed. The instruction bytes could now be grouped together,
630 and displayed in the endianness of the instruction. This is the
631 same layout as used by GNU objdump when disassembling.
633 There is now 'disassemble /b' and 'record instruction-history /b'
634 which will always display the instructions bytes one at a time in
635 memory order, that is, the byte at the lowest address first.
637 For both /r and /b GDB is now better at using whitespace in order to
638 align the disassembled instruction text.
640 * The TUI no longer styles the source and assembly code highlighted by
641 the current position indicator by default. You can however
642 re-enable styling using the new "set style tui-current-position"
645 * New convenience variable $_inferior_thread_count contains the number
646 of live threads in the current inferior.
648 * When a breakpoint with multiple code locations is hit, GDB now prints
649 the code location using the syntax <breakpoint_number>.<location_number>
651 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
653 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
654 and $_hit_locno to the hit breakpoint number and code location number.
655 This allows to disable the last hit breakpoint using
656 (gdb) disable $_hit_bpnum
657 or disable only the specific breakpoint code location using
658 (gdb) disable $_hit_bpnum.$_hit_locno
659 These commands can be used inside the command list of a breakpoint to
660 automatically disable the just encountered breakpoint (or the just
661 encountered specific breakpoint code location).
662 When a breakpoint has only one location, $_hit_locno is set to 1 so that
663 (gdb) disable $_hit_bpnum.$_hit_locno
665 (gdb) disable $_hit_bpnum
666 are both disabling the breakpoint.
670 maintenance set ignore-prologue-end-flag on|off
671 maintenance show ignore-prologue-end-flag
672 This setting, which is off by default, controls whether GDB ignores the
673 PROLOGUE-END flag from the line-table when skipping prologue. This can be
674 used to force GDB to use prologue analyzers if the line-table is constructed
675 from erroneous debug information.
677 set print nibbles [on|off]
679 This controls whether the 'print/t' command will display binary values
680 in groups of four bits, known as "nibbles". The default is 'off'.
682 maintenance set libopcodes-styling on|off
683 maintenance show libopcodes-styling
684 These can be used to force off libopcodes based styling, the Python
685 Pygments styling will then be used instead.
687 set style disassembler comment
688 show style disassembler comment
689 set style disassembler immediate
690 show style disassembler immediate
691 set style disassembler mnemonic
692 show style disassembler mnemonic
693 set style disassembler register
694 show style disassembler register
695 set style disassembler address
696 show style disassembler address
697 set style disassembler symbol
698 show style disassembler symbol
699 For targets that support libopcodes based styling, these settings
700 control how various aspects of the disassembler output are styled.
701 The 'disassembler address' and 'disassembler symbol' styles are
702 aliases for the 'address' and 'function' styles respectively.
704 maintenance print frame-id [ LEVEL ]
705 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
706 not given, then print the frame-id for the currently selected frame.
708 set debug infcall on|off
710 Print additional debug messages about inferior function calls.
712 set debug solib on|off
714 Print additional debug messages about shared library handling.
716 set style tui-current-position [on|off]
717 Whether to style the source and assembly code highlighted by the
718 TUI's current position indicator. The default is off.
720 set print characters LIMIT
721 show print characters
722 This new setting is like 'set print elements', but controls how many
723 characters of a string are printed. This functionality used to be
724 covered by 'set print elements', but it can be controlled separately
725 now. LIMIT can be set to a numerical value to request that particular
726 character count, to 'unlimited' to print all characters of a string,
727 or to 'elements', which is also the default, to follow the setting of
728 'set print elements' as it used to be.
730 print -characters LIMIT
731 This new option to the 'print' command has the same effect as a temporary
732 use of 'set print characters'.
736 document user-defined
737 It is now possible to document user-defined aliases.
738 When a user-defined alias is documented, the help and apropos commands
739 use the provided documentation instead of the documentation of the
741 Documenting a user-defined alias is particularly useful when the alias
742 is a set of nested 'with' commands to avoid showing the help of
743 the with command for an alias that will in fact launch the
744 last command given in the nested commands.
746 maintenance info line-table
747 Add a PROLOGUE-END column to the output which indicates that an
748 entry corresponds to an address where a breakpoint should be placed
749 to be at the first instruction past a function's prologue.
753 set debug aix-solib on|off
755 set debug solib-frv on|off
757 Removed in favor of "set/show debug solib".
759 maintenance info program-spaces
760 This command now includes a 'Core File' column which indicates the
761 name of the core file associated with each program space.
765 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
767 GNU/Linux/CSKY (gdbserver) csky*-*linux*
773 ** The async record stating the stopped reason 'breakpoint-hit' now
774 contains an optional field locno giving the code location number
775 when the breakpoint has multiple code locations.
779 ** GDB will now reformat the doc string for gdb.Command and
780 gdb.Parameter sub-classes to remove unnecessary leading
781 whitespace from each line before using the string as the help
784 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
785 that formats ADDRESS as 'address <symbol+offset>', where symbol is
786 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
787 This is the same format that GDB uses when printing address, symbol,
788 and offset information from the disassembler.
790 ** New function gdb.current_language that returns the name of the
791 current language. Unlike gdb.parameter('language'), this will
794 ** New method gdb.Frame.language that returns the name of the
797 ** New Python API for wrapping GDB's disassembler:
799 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
800 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
801 ARCH is either None or a string containing a bfd architecture
802 name. DISASSEMBLER is registered as a disassembler for
803 architecture ARCH, or for all architectures if ARCH is None.
804 The previous disassembler registered for ARCH is returned, this
805 can be None if no previous disassembler was registered.
807 - gdb.disassembler.Disassembler is the class from which all
808 disassemblers should inherit. Its constructor takes a string,
809 a name for the disassembler, which is currently only used in
810 some debug output. Sub-classes should override the __call__
811 method to perform disassembly, invoking __call__ on this base
812 class will raise an exception.
814 - gdb.disassembler.DisassembleInfo is the class used to describe
815 a single disassembly request from GDB. An instance of this
816 class is passed to the __call__ method of
817 gdb.disassembler.Disassembler and has the following read-only
818 attributes: 'address', and 'architecture', as well as the
819 following method: 'read_memory'.
821 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
822 calls GDB's builtin disassembler on INFO, which is a
823 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
824 optional, its default value is None. If MEMORY_SOURCE is not
825 None then it must be an object that has a 'read_memory' method.
827 - gdb.disassembler.DisassemblerResult is a class that can be used
828 to wrap the result of a call to a Disassembler. It has
829 read-only attributes 'length' and 'string'.
831 ** gdb.Objfile now has an attribute named "is_file". This is True
832 if the objfile comes from a file, and False otherwise.
834 ** New function gdb.print_options that returns a dictionary of the
835 prevailing print options, in the form accepted by
836 gdb.Value.format_string.
838 ** gdb.Value.format_string now uses the format provided by 'print',
839 if it is called during a 'print' or other similar operation.
841 ** gdb.Value.format_string now accepts the 'summary' keyword. This
842 can be used to request a shorter representation of a value, the
843 way that 'set print frame-arguments scalars' does.
845 ** New Python type gdb.BreakpointLocation.
846 The new attribute 'locations' of gdb.Breakpoint returns a list of
847 gdb.BreakpointLocation objects specifying the locations where the
848 breakpoint is inserted into the debuggee.
850 ** The gdb.register_window_type method now restricts the set of
851 acceptable window names. The first character of a window's name
852 must start with a character in the set [a-zA-Z], every subsequent
853 character of a window's name must be in the set [-_.a-zA-Z0-9].
855 * New features in the GDB remote stub, GDBserver
857 ** GDBserver is now supported on LoongArch GNU/Linux.
859 ** GDBserver is now supported on CSKY GNU/Linux.
861 * LoongArch floating-point support
863 GDB now supports floating-point on LoongArch GNU/Linux.
865 * AMD GPU ROCm debugging support
867 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
870 *** Changes in GDB 12
872 * DBX mode is deprecated, and will be removed in GDB 13
874 * GDB 12 is the last release of GDB that will support building against
875 Python 2. From GDB 13, it will only be possible to build GDB itself
876 with Python 3 support.
878 * The disable-randomization setting now works on Windows.
880 * Improved C++ template support
882 GDB now treats functions/types involving C++ templates like it does function
883 overloads. Users may omit parameter lists to set breakpoints on families of
884 template functions, including types/functions composed of multiple template types:
886 (gdb) break template_func(template_1, int)
888 The above will set breakpoints at every function `template_func' where
889 the first function parameter is any template type named `template_1' and
890 the second function parameter is `int'.
892 TAB completion also gains similar improvements.
894 * The FreeBSD native target now supports async mode.
900 Enable or disable multithreaded symbol loading. This is enabled
901 by default, but passing --disable-threading or --enable-threading=no
902 to configure will disable it.
904 Disabling this can cause a performance penalty when there are a lot of
905 symbols to load, but is useful for debugging purposes.
909 maint set backtrace-on-fatal-signal on|off
910 maint show backtrace-on-fatal-signal
911 This setting is 'on' by default. When 'on' GDB will print a limited
912 backtrace to stderr in the situation where GDB terminates with a
913 fatal signal. This only supported on some platforms where the
914 backtrace and backtrace_symbols_fd functions are available.
916 set source open on|off
918 This setting, which is on by default, controls whether GDB will try
919 to open source code files. Switching this off will stop GDB trying
920 to open and read source code files, which can be useful if the files
921 are located over a slow network connection.
925 These are now deprecated aliases for "set max-value-size" and
926 "show max-value-size".
928 task apply [all | TASK-IDS...] [FLAG]... COMMAND
929 Like "thread apply", but applies COMMAND to Ada tasks.
932 Watchpoints can now be restricted to a specific Ada task.
934 maint set internal-error backtrace on|off
935 maint show internal-error backtrace
936 maint set internal-warning backtrace on|off
937 maint show internal-warning backtrace
938 GDB can now print a backtrace of itself when it encounters either an
939 internal-error, or an internal-warning. This is on by default for
940 internal-error and off by default for internal-warning.
943 Deprecated and replaced by "set logging enabled on|off".
945 set logging enabled on|off
947 These commands set or show whether logging is enabled or disabled.
950 You can now exit GDB by using the new command "exit", in addition to
951 the existing "quit" command.
953 set debug threads on|off
955 Print additional debug messages about thread creation and deletion.
957 set debug linux-nat on|off
959 These new commands replaced the old 'set debug lin-lwp' and 'show
960 debug lin-lwp' respectively. Turning this setting on prints debug
961 messages relating to GDB's handling of native Linux inferiors.
963 maint flush source-cache
964 Flush the contents of the source code cache.
966 maint set gnu-source-highlight enabled on|off
967 maint show gnu-source-highlight enabled
968 Whether GDB should use the GNU Source Highlight library for adding
969 styling to source code. When off, the library will not be used, even
970 when available. When GNU Source Highlight isn't used, or can't add
971 styling to a particular source file, then the Python Pygments
972 library will be used instead.
974 set suppress-cli-notifications (on|off)
975 show suppress-cli-notifications
976 This controls whether printing the notifications is suppressed for CLI.
977 CLI notifications occur when you change the selected context
978 (i.e., the current inferior, thread and/or the frame), or when
979 the program being debugged stops (e.g., because of hitting a
980 breakpoint, completing source-stepping, an interrupt, etc.).
982 set style disassembler enabled on|off
983 show style disassembler enabled
984 If GDB is compiled with Python support, and the Python Pygments
985 package is available, then, when this setting is on, disassembler
986 output will have styling applied.
988 set ada source-charset
989 show ada source-charset
990 Set the character set encoding that is assumed for Ada symbols. Valid
991 values for this follow the values that can be passed to the GNAT
992 compiler via the '-gnati' option. The default is ISO-8859-1.
998 These are the new names for the old 'layout', 'focus', 'refresh',
999 and 'winheight' tui commands respectively. The old names still
1000 exist as aliases to these new commands.
1004 The new command 'tui window width', and the alias 'winwidth' allow
1005 the width of a tui window to be adjusted when windows are laid out
1008 set debug tui on|off
1010 Control the display of debug output about GDB's tui.
1015 Printing of floating-point values with base-modifying formats like
1016 /x has been changed to display the underlying bytes of the value in
1017 the desired base. This was GDB's documented behavior, but was never
1018 implemented correctly.
1021 This command can now print a reply, if the reply includes
1022 non-printable characters. Any non-printable characters are printed
1023 as escaped hex, e.g. \x?? where '??' is replaces with the value of
1024 the non-printable character.
1027 The clone-inferior command now ensures that the TTY, CMD and ARGS
1028 settings are copied from the original inferior to the new one.
1029 All modifications to the environment variables done using the 'set
1030 environment' or 'unset environment' commands are also copied to the new
1033 set debug lin-lwp on|off
1035 These commands have been removed from GDB. The new command 'set
1036 debug linux-nat' and 'show debug linux-nat' should be used
1040 This command now includes information about the width of the tui
1041 windows in its output.
1047 These commands are now aliases for the 'tui layout', 'tui focus',
1048 'tui refresh', and 'tui window height' commands respectively.
1050 * GDB's Ada parser now supports an extension for specifying the exact
1051 byte contents of a floating-point literal. This can be useful for
1052 setting floating-point registers to a precise value without loss of
1053 precision. The syntax is an extension of the based literal syntax.
1054 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
1055 of the floating-point type, and the "f" is the marker for floating
1060 ** The '-add-inferior' with no option flags now inherits the
1061 connection of the current inferior, this restores the behaviour of
1062 GDB as it was prior to GDB 10.
1064 ** The '-add-inferior' command now accepts a '--no-connection'
1065 option, which causes the new inferior to start without a
1068 ** The default version of the MI interpreter is now 4 (-i=mi4).
1070 ** The "script" field in breakpoint output (which is syntactically
1071 incorrect in MI 3 and below) has changed in MI 4 to become a list.
1072 This affects the following commands and events:
1076 - =breakpoint-created
1077 - =breakpoint-modified
1079 The -fix-breakpoint-script-output command can be used to enable
1080 this behavior with previous MI versions.
1084 GNU/Linux/LoongArch loongarch*-*-linux*
1092 ** New function gdb.add_history(), which takes a gdb.Value object
1093 and adds the value it represents to GDB's history list. An
1094 integer, the index of the new item in the history list, is
1097 ** New function gdb.history_count(), which returns the number of
1098 values in GDB's value history.
1100 ** New gdb.events.gdb_exiting event. This event is called with a
1101 gdb.GdbExitingEvent object which has the read-only attribute
1102 'exit_code', which contains the value of the GDB exit code. This
1103 event is triggered once GDB decides it is going to exit, but
1104 before GDB starts to clean up its internal state.
1106 ** New function gdb.architecture_names(), which returns a list
1107 containing all of the possible Architecture.name() values. Each
1110 ** New function gdb.Architecture.integer_type(), which returns an
1111 integer type given a size and a signed-ness.
1113 ** New gdb.TargetConnection object type that represents a connection
1114 (as displayed by the 'info connections' command). A sub-class,
1115 gdb.RemoteTargetConnection, is used to represent 'remote' and
1116 'extended-remote' connections.
1118 ** The gdb.Inferior type now has a 'connection' property which is an
1119 instance of gdb.TargetConnection, the connection used by this
1120 inferior. This can be None if the inferior has no connection.
1122 ** New 'gdb.events.connection_removed' event registry, which emits a
1123 'gdb.ConnectionEvent' when a connection is removed from GDB.
1124 This event has a 'connection' property, a gdb.TargetConnection
1125 object for the connection being removed.
1127 ** New gdb.connections() function that returns a list of all
1128 currently active connections.
1130 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
1131 is equivalent to the existing 'maint packet' CLI command; it
1132 allows a user specified packet to be sent to the remote target.
1134 ** New function gdb.host_charset(), returns a string, which is the
1135 name of the current host charset.
1137 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
1140 ** New gdb.with_parameter(NAME, VALUE). This returns a context
1141 manager that temporarily sets the gdb parameter NAME to VALUE,
1142 then resets it when the context is exited.
1144 ** The gdb.Value.format_string method now takes a 'styling'
1145 argument, which is a boolean. When true, the returned string can
1146 include escape sequences to apply styling. The styling will only
1147 be present if styling is otherwise turned on in GDB (see 'help
1148 set styling'). When false, which is the default if the argument
1149 is not given, then no styling is applied to the returned string.
1151 ** New read-only attribute gdb.InferiorThread.details, which is
1152 either a string, containing additional, target specific thread
1153 state information, or None, if there is no such additional
1156 ** New read-only attribute gdb.Type.is_scalar, which is True for
1157 scalar types, and False for all other types.
1159 ** New read-only attribute gdb.Type.is_signed. This attribute
1160 should only be read when Type.is_scalar is True, and will be True
1161 for signed types, and False for all other types. Attempting to
1162 read this attribute for non-scalar types will raise a ValueError.
1164 ** It is now possible to add GDB/MI commands implemented in Python.
1166 * New features in the GDB remote stub, GDBserver
1168 ** GDBserver is now supported on OpenRISC GNU/Linux.
1170 * New native configurations
1172 GNU/Linux/OpenRISC or1k*-*-linux*
1174 *** Changes in GDB 11
1176 * The 'set disassembler-options' command now supports specifying options
1179 * GDB now supports general memory tagging functionality if the underlying
1180 architecture supports the proper primitives and hooks. Currently this is
1181 enabled only for AArch64 MTE.
1185 - Additional information when the inferior crashes with a SIGSEGV caused by
1186 a memory tag violation.
1188 - A new modifier 'm' for the "x" command, which displays allocation tags for a
1189 particular memory range.
1191 - Display of memory tag mismatches by "print", for addresses and
1192 pointers, if memory tagging is supported by the architecture.
1194 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
1199 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
1201 The MI -break-insert and -dprintf-insert commands now support a
1202 new "--qualified" option that makes GDB interpret a specified
1203 function name as a complete fully-qualified name. This is the
1204 equivalent of the CLI's "break -qualified" and "dprintf
1207 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
1209 The MI -break-insert and -dprintf-insert commands now support a
1210 '--force-condition' flag to forcibly define a condition even when
1211 the condition is invalid at all locations of the breakpoint. This
1212 is equivalent to the '-force-condition' flag of the CLI's "break"
1215 ** '-break-condition --force'
1217 The MI -break-condition command now supports a '--force' flag to
1218 forcibly define a condition even when the condition is invalid at
1219 all locations of the selected breakpoint. This is equivalent to
1220 the '-force' flag of the CLI's "cond" command.
1222 ** '-file-list-exec-source-files [--group-by-objfile]
1223 [--basename | --dirname]
1226 The existing -file-list-exec-source-files command now takes an
1227 optional REGEXP which is used to filter the source files that are
1228 included in the results.
1230 By default REGEXP is matched against the full filename of the
1231 source file. When one of --basename or --dirname is given then
1232 REGEXP is only matched against the specified part of the full
1235 When the optional --group-by-objfile flag is used the output
1236 format is changed, the results are now a list of object files
1237 (executable and libraries) with the source files that are
1238 associated with each object file.
1240 The results from -file-list-exec-source-files now include a
1241 'debug-fully-read' field which takes the value 'true' or 'false'.
1242 A 'true' value indicates the source file is from a compilation
1243 unit that has had its debug information fully read in by GDB, a
1244 value of 'false' indicates GDB has only performed a partial scan
1245 of the debug information so far.
1247 * GDB now supports core file debugging for x86_64 Cygwin programs.
1249 * GDB will now look for the .gdbinit file in a config directory before
1250 looking for ~/.gdbinit. The file is searched for in the following
1251 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
1252 $HOME/.gdbinit. On Apple hosts the search order is instead:
1253 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
1255 * GDB now supports fixed point types which are described in DWARF
1256 as base types with a fixed-point encoding. Additionally, support
1257 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
1260 For Ada, this allows support for fixed point types without requiring
1261 the use of the GNAT encoding (based on information added to the type's
1262 name following a GNAT-specific format).
1264 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
1265 or ~/.gdbearlyinit if these files are present. These files are
1266 processed earlier than any of the other initialization files and
1267 can affect parts of GDB's startup that previously had already been
1268 completed before the initialization files were read, for example
1269 styling of the initial GDB greeting.
1271 * GDB now has two new options "--early-init-command" and
1272 "--early-init-eval-command" with corresponding short options "-eix"
1273 and "-eiex" that allow options (that would normally appear in a
1274 gdbearlyinit file) to be passed on the command line.
1276 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
1277 now understood by GDB, and can be used to describe the vector
1278 registers of a target. The precise requirements of this register
1279 feature are documented in the GDB manual.
1281 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
1282 supported by GDB and describes a new VPR register from the ARM MVE
1283 (Helium) extension. See the GDB manual for more information.
1287 ** TUI windows now support mouse actions. The mouse wheel scrolls
1288 the appropriate window.
1290 ** Key combinations that do not have a specific action on the
1291 focused window are passed to GDB. For example, you now can use
1292 Ctrl-Left/Ctrl-Right to move between words in the command window
1293 regardless of which window is in focus. Previously you would
1294 need to focus on the command window for such key combinations to
1299 set debug event-loop
1300 show debug event-loop
1301 Control the display of debug output about GDB's event loop.
1303 set print memory-tag-violations
1304 show print memory-tag-violations
1305 Control whether to display additional information about memory tag violations
1306 when printing pointers and addresses. Architecture support for memory
1307 tagging is required for this option to have an effect.
1309 maintenance flush symbol-cache
1310 maintenance flush register-cache
1311 These new commands are equivalent to the already existing commands
1312 'maintenance flush-symbol-cache' and 'flushregs' respectively.
1314 maintenance flush dcache
1315 A new command to flush the dcache.
1317 maintenance info target-sections
1318 Print GDB's internal target sections table.
1320 maintenance info jit
1321 Print the JIT code objects in the inferior known to GDB.
1323 memory-tag show-logical-tag POINTER
1324 Print the logical tag for POINTER.
1325 memory-tag with-logical-tag POINTER TAG
1326 Print POINTER with logical tag TAG.
1327 memory-tag show-allocation-tag ADDRESS
1328 Print the allocation tag for ADDRESS.
1329 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1330 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1331 memory-tag check POINTER
1332 Validate that POINTER's logical tag matches the allocation tag.
1334 set startup-quietly on|off
1335 show startup-quietly
1336 When 'on', this causes GDB to act as if "-silent" were passed on the
1337 command line. This command needs to be added to an early
1338 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1341 set print type hex on|off
1343 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1344 and offsets of struct members. When 'off', decimal notation is used.
1346 set python ignore-environment on|off
1347 show python ignore-environment
1348 When 'on', this causes GDB's builtin Python to ignore any
1349 environment variables that would otherwise affect how Python
1350 behaves. This command needs to be added to an early initialization
1351 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1353 set python dont-write-bytecode auto|on|off
1354 show python dont-write-bytecode
1355 When 'on', this causes GDB's builtin Python to not write any
1356 byte-code (.pyc files) to disk. This command needs to be added to
1357 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1358 order to affect GDB. When 'off' byte-code will always be written.
1359 When set to 'auto' (the default) Python will check the
1360 PYTHONDONTWRITEBYTECODE environment variable.
1364 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1365 [-force-condition] [if CONDITION]
1366 This command would previously refuse setting a breakpoint if the
1367 CONDITION expression is invalid at a location. It now accepts and
1368 defines the breakpoint if there is at least one location at which
1369 the CONDITION is valid. The locations for which the CONDITION is
1370 invalid, are automatically disabled. If CONDITION is invalid at all
1371 of the locations, setting the breakpoint is still rejected. However,
1372 the '-force-condition' flag can be used in this case for forcing GDB to
1373 define the breakpoint, making all the current locations automatically
1374 disabled. This may be useful if the user knows the condition will
1375 become meaningful at a future location, e.g. due to a shared library
1378 condition [-force] N COND
1379 The behavior of this command is changed the same way for the 'break'
1380 command as explained above. The '-force' flag can be used to force
1381 GDB into defining the condition even when COND is invalid for all the
1382 current locations of breakpoint N.
1385 maintenance flush-symbol-cache
1386 These commands are deprecated in favor of the new commands
1387 'maintenance flush register-cache' and 'maintenance flush
1388 symbol-cache' respectively.
1390 set style version foreground COLOR
1391 set style version background COLOR
1392 set style version intensity VALUE
1393 Control the styling of GDB's version number text.
1396 When the ID parameter is omitted, then this command prints information
1397 about the current inferior. When the ID parameter is present, the
1398 behavior of the command is unchanged and have the inferior ID become
1399 the current inferior.
1401 maintenance info sections
1402 The ALLOBJ keyword has been replaced with an -all-objects command
1403 line flag. It is now possible to filter which sections are printed
1404 even when -all-objects is passed.
1406 ptype[/FLAGS] TYPE | EXPRESSION
1407 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
1408 notation is used when printing sizes and offsets of struct members.
1409 When '/d' is set, decimal notation is used when printing sizes and
1410 offsets of struct members. Default behavior is given by 'show print
1414 The info sources command output has been restructured. The results
1415 are now based around a list of objfiles (executable and libraries),
1416 and for each objfile the source files that are part of that objfile
1419 * Removed targets and native configurations
1421 ARM Symbian arm*-*-symbianelf*
1423 * New remote packets
1426 Request the remote to send allocation tags for a particular memory range.
1428 Request the remote to store the specified allocation tags to the requested
1433 ** Improved support for rvalue reference values:
1434 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1435 value-referenced-value procedure now handles rvalue reference
1438 ** New procedures for obtaining value variants:
1439 value-reference-value, value-rvalue-reference-value and
1442 ** Temporary breakpoints can now be created with make-breakpoint and
1443 tested for using breakpoint-temporary?.
1447 ** Inferior objects now contain a read-only 'connection_num' attribute that
1448 gives the connection number as seen in 'info connections' and
1451 ** New method gdb.Frame.level() which returns the stack level of the
1454 ** New method gdb.PendingFrame.level() which returns the stack level
1455 of the frame object.
1457 ** When hitting a catchpoint, the Python API will now emit a
1458 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1459 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1461 ** Python TUI windows can now receive mouse click events. If the
1462 Window object implements the click method, it is called for each
1463 mouse click event in this window.
1465 *** Changes in GDB 10
1467 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1468 and "org.gnu.gdb.arc.aux". The old names are still supported but
1469 must be considered obsolete. They will be deprecated after some
1472 * Help and apropos commands will now show the documentation of a
1473 command only once, even if that command has one or more aliases.
1474 These commands now show the command name, then all of its aliases,
1475 and finally the description of the command.
1477 * 'help aliases' now shows only the user defined aliases. GDB predefined
1478 aliases are shown together with their aliased command.
1480 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1481 debugging information as well as source code.
1483 When built with debuginfod, GDB can automatically query debuginfod
1484 servers for the separate debug files and source code of the executable
1487 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1488 requires libdebuginfod, the debuginfod client library).
1490 debuginfod is distributed with elfutils, starting with version 0.178.
1492 You can get the latest version from https://sourceware.org/elfutils.
1494 * Multi-target debugging support
1496 GDB now supports debugging multiple target connections
1497 simultaneously. For example, you can now have each inferior
1498 connected to different remote servers running in different machines,
1499 or have one inferior debugging a local native process, an inferior
1500 debugging a core dump, etc.
1502 This support is experimental and comes with some limitations -- you
1503 can only resume multiple targets simultaneously if all targets
1504 support non-stop mode, and all remote stubs or servers must support
1505 the same set of remote protocol features exactly. See also "info
1506 connections" and "add-inferior -no-connection" below, and "maint set
1507 target-non-stop" in the user manual.
1509 * New features in the GDB remote stub, GDBserver
1511 ** GDBserver is now supported on ARC GNU/Linux.
1513 ** GDBserver is now supported on RISC-V GNU/Linux.
1515 ** GDBserver no longer supports these host triplets:
1517 i[34567]86-*-lynxos*
1526 i[34567]86-*-mingw32ce*
1528 * Debugging MS-Windows processes now sets $_exitsignal when the
1529 inferior is terminated by a signal, instead of setting $_exitcode.
1531 * Multithreaded symbol loading has now been enabled by default on systems
1532 that support it (see entry for GDB 9, below), providing faster
1533 performance for programs with many symbols.
1535 * The $_siginfo convenience variable now also works on Windows targets,
1536 and will display the EXCEPTION_RECORD of the last handled exception.
1538 * TUI windows can now be arranged horizontally.
1540 * The command history filename can now be set to the empty string
1541 either using 'set history filename' or by setting 'GDBHISTFILE=' in
1542 the environment. The effect of setting this filename to the empty
1543 string is that GDB will not try to load any previous command
1546 * On Windows targets, it is now possible to debug 32-bit programs with a
1551 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1552 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1553 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
1554 running process, this new option indicates whether to detect
1555 a mismatch between the current executable file loaded by GDB and the
1556 executable file used to start the process. If 'ask', the default,
1557 display a warning and ask the user whether to load the process
1558 executable file; if 'warn', just display a warning; if 'off', don't
1559 attempt to detect a mismatch.
1561 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1562 Define a new TUI layout, specifying its name and the windows that
1565 maintenance print xml-tdesc [FILE]
1566 Prints the current target description as an XML document. If the
1567 optional FILE is provided (which is an XML target description) then
1568 the target description is read from FILE into GDB, and then
1571 maintenance print core-file-backed-mappings
1572 Prints file-backed mappings loaded from a core file's note section.
1573 Output is expected to be similar to that of "info proc mappings".
1575 set debug fortran-array-slicing on|off
1576 show debug fortran-array-slicing
1577 Print debugging when taking slices of Fortran arrays.
1579 set fortran repack-array-slices on|off
1580 show fortran repack-array-slices
1581 When taking slices from Fortran arrays and strings, if the slice is
1582 non-contiguous within the original value then, when this option is
1583 on, the new value will be repacked into a single contiguous value.
1584 When this option is off, then the value returned will consist of a
1585 descriptor that describes the slice within the memory of the
1586 original parent value.
1590 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1591 The alias command can now specify default args for an alias.
1592 GDB automatically prepends the alias default args to the argument list
1593 provided explicitly by the user.
1594 For example, to have a backtrace with full details, you can define
1595 an alias 'bt_ALL' as
1596 'alias bt_ALL = backtrace -entry-values both -frame-arg all
1597 -past-main -past-entry -full'.
1598 Alias default arguments can also use a set of nested 'with' commands,
1599 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1600 defines the alias pp10 that will pretty print a maximum of 10 elements
1601 of the given expression (if the expression is an array).
1605 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
1606 BPF bpf-unknown-none
1611 ** gdb.register_window_type can be used to implement new TUI windows
1614 ** Dynamic types can now be queried. gdb.Type has a new attribute,
1615 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
1616 field of a dynamic type may have None for its "bitpos" attribute
1619 ** Commands written in Python can be in the "TUI" help class by
1620 registering with the new constant gdb.COMMAND_TUI.
1622 ** New method gdb.PendingFrame.architecture () to retrieve the
1623 architecture of the pending frame.
1625 ** New gdb.Architecture.registers method that returns a
1626 gdb.RegisterDescriptorIterator object, an iterator that returns
1627 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
1628 way to query the registers available for an architecture.
1630 ** New gdb.Architecture.register_groups method that returns a
1631 gdb.RegisterGroupIterator object, an iterator that returns
1632 gdb.RegisterGroup objects. The new RegisterGroup is a way to
1633 discover the available register groups.
1637 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1639 ** Procedures 'memory-port-read-buffer-size',
1640 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1641 and 'set-memory-port-write-buffer-size!' are deprecated. When
1642 using Guile 2.2 and later, users who need to control the size of
1643 a memory port's internal buffer can use the 'setvbuf' procedure.
1645 *** Changes in GDB 9
1647 * 'thread-exited' event is now available in the annotations interface.
1649 * New built-in convenience variables $_gdb_major and $_gdb_minor
1650 provide the GDB version. They are handy for conditionally using
1651 features available only in or since specific GDB versions, in
1652 scripts that should work error-free with many different versions,
1653 such as in system-wide init files.
1655 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1656 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1657 of the GDB settings and the GDB maintenance settings. They are handy
1658 for changing the logic of user defined commands depending on the
1659 current GDB settings.
1661 * GDB now supports Thread Local Storage (TLS) variables on several
1662 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1663 architectures require kernel changes. TLS is not yet supported for
1664 amd64 and i386 process core dumps.
1666 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1667 addresses that required unmasking are shown in the backtrace with the
1670 * Two new convenience functions $_cimag and $_creal that extract the
1671 imaginary and real parts respectively from complex numbers.
1673 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1674 provide the exitcode or exit status of the shell commands launched by
1675 GDB commands such as "shell", "pipe" and "make".
1677 * The command define-prefix can now define user defined prefix commands.
1678 User defined commands can now be defined using these user defined prefix
1681 * Command names can now use the . character.
1683 * The RX port now supports XML target descriptions.
1685 * GDB now shows the Ada task names at more places, e.g. in task switching
1688 * GDB can now be compiled with Python 3 on Windows.
1690 * New convenience variable $_ada_exception holds the address of the
1691 Ada exception being thrown. This is set by Ada-related catchpoints.
1693 * GDB can now place breakpoints on nested functions and subroutines in
1694 Fortran code. The '::' operator can be used between parent and
1695 child scopes when placing breakpoints, for example:
1697 (gdb) break outer_function::inner_function
1699 The 'outer_function::' prefix is only needed if 'inner_function' is
1700 not visible in the current scope.
1702 * In addition to the system-wide gdbinit file, if configured with
1703 --with-system-gdbinit-dir, GDB will now also load files in that directory
1704 as system gdbinit files, unless the -nx or -n flag is provided. Files
1705 with extensions .gdb, .py and .scm are supported as long as GDB was
1706 compiled with support for that language.
1708 * GDB now supports multithreaded symbol loading for higher performance.
1709 This feature is still in testing, so it is disabled by default. You
1710 can turn it on using 'maint set worker-threads unlimited'.
1714 ** The gdb.Value type has a new method 'format_string' which returns a
1715 string representing the value. The formatting is controlled by the
1716 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1717 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1718 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1720 ** gdb.Type has a new property 'objfile' which returns the objfile the
1721 type was defined in.
1723 ** The frame information printed by the python frame filtering code
1724 is now consistent with what the 'backtrace' command prints when
1725 there are no filters, or when the 'backtrace' '-no-filters' option
1728 ** The new function gdb.lookup_static_symbol can be used to look up
1729 symbols with static linkage.
1731 ** The new function gdb.lookup_static_symbols can be used to look up
1732 all static symbols with static linkage.
1734 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1735 'lookup_static_symbol' to lookup a symbol from this objfile only.
1737 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1738 this block (e.g. block['local_variable']).
1742 | [COMMAND] | SHELL_COMMAND
1743 | -d DELIM COMMAND DELIM SHELL_COMMAND
1744 pipe [COMMAND] | SHELL_COMMAND
1745 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1746 Executes COMMAND and sends its output to SHELL_COMMAND.
1747 With no COMMAND, repeat the last executed command
1748 and send its output to SHELL_COMMAND.
1750 define-prefix COMMAND
1751 Define or mark a command as a user-defined prefix command.
1753 with SETTING [VALUE] [-- COMMAND]
1754 w SETTING [VALUE] [-- COMMAND]
1755 Temporarily set SETTING, run COMMAND, and restore SETTING.
1756 Usage: with SETTING -- COMMAND
1757 With no COMMAND, repeats the last executed command.
1758 SETTING is any GDB setting you can change with the "set"
1759 subcommands. For example, 'with language c -- print someobj'
1760 temporarily switches to the C language in order to print someobj.
1761 Settings can be combined: 'w lang c -- w print elements unlimited --
1762 usercmd' switches to the C language and runs usercmd with no limit
1763 of array elements to print.
1765 maint with SETTING [VALUE] [-- COMMAND]
1766 Like "with", but works with "maintenance set" settings.
1768 set may-call-functions [on|off]
1769 show may-call-functions
1770 This controls whether GDB will attempt to call functions in
1771 the program, such as with expressions in the print command. It
1772 defaults to on. Calling functions in the program being debugged
1773 can have undesired side effects. It is now possible to forbid
1774 such function calls. If function calls are forbidden, GDB will throw
1775 an error when a command (such as print expression) calls a function
1778 set print finish [on|off]
1780 This controls whether the `finish' command will display the value
1781 that is returned by the current function. When `off', the value is
1782 still entered into the value history, but it is not printed. The
1786 show print max-depth
1787 Allows deeply nested structures to be simplified when printing by
1788 replacing deeply nested parts (beyond the max-depth) with ellipses.
1789 The default max-depth is 20, but this can be set to unlimited to get
1790 the old behavior back.
1792 set print raw-values [on|off]
1793 show print raw-values
1794 By default, GDB applies the enabled pretty printers when printing a
1795 value. This allows to ignore the enabled pretty printers for a series
1796 of commands. The default is 'off'.
1798 set logging debugredirect [on|off]
1799 By default, GDB debug output will go to both the terminal and the logfile.
1800 Set if you want debug output to go only to the log file.
1802 set style title foreground COLOR
1803 set style title background COLOR
1804 set style title intensity VALUE
1805 Control the styling of titles.
1807 set style highlight foreground COLOR
1808 set style highlight background COLOR
1809 set style highlight intensity VALUE
1810 Control the styling of highlightings.
1812 maint set worker-threads
1813 maint show worker-threads
1814 Control the number of worker threads that can be used by GDB. The
1815 default is 0. "unlimited" lets GDB choose a number that is
1816 reasonable. Currently worker threads are only used when demangling
1817 the names of linker symbols.
1819 set style tui-border foreground COLOR
1820 set style tui-border background COLOR
1821 Control the styling of TUI borders.
1823 set style tui-active-border foreground COLOR
1824 set style tui-active-border background COLOR
1825 Control the styling of the active TUI border.
1827 maint set test-settings KIND
1828 maint show test-settings KIND
1829 A set of commands used by the testsuite for exercising the settings
1832 maint set tui-resize-message [on|off]
1833 maint show tui-resize-message
1834 Control whether GDB prints a message each time the terminal is
1835 resized when in TUI mode. This is primarily useful for testing the
1838 set print frame-info [short-location|location|location-and-address
1839 |source-and-location|source-line|auto]
1840 show print frame-info
1841 This controls what frame information is printed by the commands printing
1842 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1843 'frame', 'stepi'. The python frame filtering also respect this setting.
1844 The 'backtrace' '-frame-info' option can override this global setting.
1846 set tui compact-source
1847 show tui compact-source
1849 Enable the "compact" display mode for the TUI source window. The
1850 compact display uses only as much space as is needed for the line
1851 numbers in the current file, and only a single space to separate the
1852 line numbers from the source.
1854 info modules [-q] [REGEXP]
1855 Return a list of Fortran modules matching REGEXP, or all modules if
1858 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1859 Return a list of functions within all modules, grouped by module.
1860 The list of functions can be restricted with the optional regular
1861 expressions. MODULE_REGEXP matches against the module name,
1862 TYPE_REGEXP matches against the function type signature, and REGEXP
1863 matches against the function name.
1865 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1866 Return a list of variables within all modules, grouped by module.
1867 The list of variables can be restricted with the optional regular
1868 expressions. MODULE_REGEXP matches against the module name,
1869 TYPE_REGEXP matches against the variable type, and REGEXP matches
1870 against the variable name.
1872 set debug remote-packet-max-chars
1873 show debug remote-packet-max-chars
1874 Controls the number of characters to output in a remote packet when using
1876 The default is 512 bytes.
1879 Lists the target connections currently in use.
1884 The "help" command uses the title style to enhance the
1885 readibility of its output by styling the classes and
1889 Similarly to "help", the "apropos" command also uses the
1890 title style for the command names. "apropos" accepts now
1891 a flag "-v" (verbose) to show the full documentation
1892 of matching commands and to use the highlight style to mark
1893 the documentation parts matching REGEXP.
1897 The GDB printf and eval commands can now print C-style and Ada-style
1898 string convenience variables without calling functions in the program.
1899 This allows to do formatted printing of strings without having
1900 a running inferior, or when debugging a core dump.
1902 info sources [-dirname | -basename] [--] [REGEXP]
1903 This command has now optional arguments to only print the files
1904 whose names match REGEXP. The arguments -dirname and -basename
1905 allow to restrict matching respectively to the dirname and basename
1909 The "show style" and its subcommands are now styling
1910 a style name in their output using its own style, to help
1911 the user visualize the different styles.
1913 set print frame-arguments
1914 The new value 'presence' indicates to only indicate the presence of
1915 arguments using ..., instead of printing argument names and values.
1917 set print raw-frame-arguments
1918 show print raw-frame-arguments
1920 These commands replace the similarly-named "set/show print raw
1921 frame-arguments" commands (now with a dash instead of a space). The
1922 old commands are now deprecated and may be removed in a future
1925 add-inferior [-no-connection]
1926 The add-inferior command now supports a "-no-connection" flag that
1927 makes the new inferior start with no target connection associated.
1928 By default, the new inferior inherits the target connection of the
1929 current inferior. See also "info connections".
1932 This command's output now includes a new "Connection" column
1933 indicating which target connection an inferior is bound to. See
1934 "info connections" above.
1936 maint test-options require-delimiter
1937 maint test-options unknown-is-error
1938 maint test-options unknown-is-operand
1939 maint show test-options-completion-result
1940 Commands used by the testsuite to validate the command options
1943 focus, winheight, +, -, >, <
1944 These commands are now case-sensitive.
1946 * New command options, command completion
1948 GDB now has a standard infrastructure to support dash-style command
1949 options ('-OPT'). One benefit is that commands that use it can
1950 easily support completion of command line arguments. Try "CMD
1951 -[TAB]" or "help CMD" to find options supported by a command. Over
1952 time, we intend to migrate most commands to this infrastructure. A
1953 number of commands got support for new command options in this
1956 ** The "print" and "compile print" commands now support a number of
1957 options that allow overriding relevant global print settings as
1958 set by "set print" subcommands:
1962 -array-indexes [on|off]
1963 -elements NUMBER|unlimited
1967 -raw-values [on|off]
1968 -repeats NUMBER|unlimited
1969 -static-members [on|off]
1974 Note that because the "print"/"compile print" commands accept
1975 arbitrary expressions which may look like options (including
1976 abbreviations), if you specify any command option, then you must
1977 use a double dash ("--") to mark the end of argument processing.
1979 ** The "backtrace" command now supports a number of options that
1980 allow overriding relevant global print settings as set by "set
1981 backtrace" and "set print" subcommands:
1983 -entry-values no|only|preferred|if-needed|both|compact|default
1984 -frame-arguments all|scalars|none
1985 -raw-frame-arguments [on|off]
1986 -frame-info auto|source-line|location|source-and-location
1987 |location-and-address|short-location
1989 -past-entry [on|off]
1991 In addition, the full/no-filters/hide qualifiers are now also
1992 exposed as command options too:
1998 ** The "frame apply", "tfaas" and "faas" commands similarly now
1999 support the following options:
2002 -past-entry [on|off]
2004 ** The new "info sources" options -dirname and -basename options
2005 are using the standard '-OPT' infrastructure.
2007 All options above can also be abbreviated. The argument of boolean
2008 (on/off) options can be 0/1 too, and also the argument is assumed
2009 "on" if omitted. This allows writing compact command invocations,
2012 (gdb) p -ra -p -o 0 -- *myptr
2014 The above is equivalent to:
2016 (gdb) print -raw-values -pretty -object off -- *myptr
2018 ** The "info types" command now supports the '-q' flag to disable
2019 printing of some header information in a similar fashion to "info
2020 variables" and "info functions".
2022 ** The "info variables", "info functions", and "whereis" commands
2023 now take a '-n' flag that excludes non-debug symbols (symbols
2024 from the symbol table, not from the debug info such as DWARF)
2027 * Completion improvements
2029 ** GDB can now complete the options of the "thread apply all" and
2030 "taas" commands, and their "-ascending" option can now be
2033 ** GDB can now complete the options of the "info threads", "info
2034 functions", "info variables", "info locals", and "info args"
2037 ** GDB can now complete the options of the "compile file" and
2038 "compile code" commands. The "compile file" command now
2039 completes on filenames.
2041 ** GDB can now complete the backtrace command's
2042 "full/no-filters/hide" qualifiers.
2044 * In settings, you can now abbreviate "unlimited".
2046 E.g., "set print elements u" is now equivalent to "set print
2047 elements unlimited".
2052 This lists all the possible completions for the rest of the line, if it
2053 were to be given as a command itself. This is intended for use by MI
2054 frontends in cases when separate CLI and MI channels cannot be used.
2056 -catch-throw, -catch-rethrow, and -catch-catch
2057 These can be used to catch C++ exceptions in a similar fashion to
2058 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
2060 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
2061 These commands are the MI equivalent of the CLI commands 'info
2062 functions', 'info types', and 'info variables' respectively.
2064 -symbol-info-modules, this is the MI equivalent of the CLI 'info
2067 -symbol-info-module-functions and -symbol-info-module-variables.
2068 These commands are the MI equivalent of the CLI commands 'info
2069 module functions' and 'info module variables'.
2073 ** The default version of the MI interpreter is now 3 (-i=mi3).
2075 ** The output of information about multi-location breakpoints (which is
2076 syntactically incorrect in MI 2) has changed in MI 3. This affects
2077 the following commands and events:
2081 - =breakpoint-created
2082 - =breakpoint-modified
2084 The -fix-multi-location-breakpoint-output command can be used to enable
2085 this behavior with previous MI versions.
2087 ** Backtraces and frames include a new optional field addr_flags which is
2088 given after the addr field. On AArch64 this contains PAC if the address
2089 has been masked in the frame. On all other targets the field is not
2094 The testsuite now creates the files gdb.cmd (containing the arguments
2095 used to launch GDB) and gdb.in (containing all the commands sent to
2096 GDB) in the output directory for each test script. Multiple invocations
2097 are appended with .1, .2, .3 etc.
2099 * Building GDB and GDBserver now requires GNU make >= 3.82.
2101 Using another implementation of the make program or an earlier version of
2102 GNU make to build GDB or GDBserver is not supported.
2104 * Building GDB now requires GNU readline >= 7.0.
2106 GDB now bundles GNU readline 8.0, but if you choose to use
2107 --with-system-readline, only readline >= 7.0 can be used.
2109 * The TUI SingleKey keymap is now named "SingleKey". This can be used
2110 from .inputrc to bind keys in this keymap. This feature is only
2111 available when gdb is built against GNU readline 8.0 or later.
2113 * Removed targets and native configurations
2115 GDB no longer supports debugging the Cell Broadband Engine. This includes
2116 both debugging standalone Cell/B.E. SPU applications and integrated debugging
2117 of Cell/B.E. applications that use both the PPU and SPU architectures.
2123 * Removed targets and native configurations
2125 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
2126 sparc*-*-solaris2.10
2128 *** Changes in GDB 8.3
2130 * GDB and GDBserver now support access to additional registers on
2131 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
2134 * GDB now has experimental support for the compilation and injection of
2135 C++ source code into the inferior. This beta release does not include
2136 support for several language features, such as templates, constructors,
2139 This feature requires GCC 7.1 or higher built with libcp1.so
2142 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
2143 can be passed using the '[ADDRESS]:PORT' notation, or the regular
2144 'ADDRESS:PORT' method.
2146 * DWARF index cache: GDB can now automatically save indices of DWARF
2147 symbols on disk to speed up further loading of the same binaries.
2149 * Ada task switching is now supported on aarch64-elf targets when
2150 debugging a program using the Ravenscar Profile. For more information,
2151 see the "Tasking Support when using the Ravenscar Profile" section
2152 in the GDB user manual.
2154 * GDB in batch mode now exits with status 1 if the last command to be
2157 * The RISC-V target now supports target descriptions.
2159 * System call catchpoints now support system call aliases on FreeBSD.
2160 When the ABI of a system call changes in FreeBSD, this is
2161 implemented by leaving a compatibility system call using the old ABI
2162 at the existing number and allocating a new system call number for
2163 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
2164 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
2165 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
2166 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
2167 so that a system call catchpoint for the 'kevent' system call will
2168 catch invocations of both the 'kevent' and 'freebsd11_kevent'
2169 binaries. This ensures that 'kevent' system calls are caught for
2170 binaries using either the old or new ABIs.
2172 * Terminal styling is now available for the CLI and the TUI. GNU
2173 Source Highlight can additionally be used to provide styling of
2174 source code snippets. See the "set style" commands, below, for more
2177 * Removed support for old demangling styles arm, edg, gnu, hp and
2182 set debug compile-cplus-types
2183 show debug compile-cplus-types
2184 Control the display of debug output about type conversion in the
2185 C++ compile feature. Commands have no effect while compiling
2186 for other languages.
2190 Control whether debug output about files/functions skipping is
2193 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
2194 Apply a command to some frames.
2195 FLAG arguments allow to control what output to produce and how to handle
2196 errors raised when applying COMMAND to a frame.
2199 Apply a command to all threads (ignoring errors and empty output).
2200 Shortcut for 'thread apply all -s COMMAND'.
2203 Apply a command to all frames (ignoring errors and empty output).
2204 Shortcut for 'frame apply all -s COMMAND'.
2207 Apply a command to all frames of all threads (ignoring errors and empty
2209 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
2211 maint set dwarf unwinders (on|off)
2212 maint show dwarf unwinders
2213 Control whether DWARF unwinders can be used.
2216 Display a list of open files for a process.
2220 Changes to the "frame", "select-frame", and "info frame" CLI commands.
2221 These commands all now take a frame specification which
2222 is either a frame level, or one of the keywords 'level', 'address',
2223 'function', or 'view' followed by a parameter. Selecting a frame by
2224 address, or viewing a frame outside the current backtrace now
2225 requires the use of a keyword. Selecting a frame by level is
2226 unchanged. The MI comment "-stack-select-frame" is unchanged.
2228 target remote FILENAME
2229 target extended-remote FILENAME
2230 If FILENAME is a Unix domain socket, GDB will attempt to connect
2231 to this socket instead of opening FILENAME as a character device.
2233 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2234 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2235 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2236 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2237 These commands can now print only the searched entities
2238 matching the provided regexp(s), giving a condition
2239 on the entity names or entity types. The flag -q disables
2240 printing headers or informations messages.
2246 These commands now determine the syntax for the shown entities
2247 according to the language chosen by `set language'. In particular,
2248 `set language auto' means to automatically choose the language of
2251 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
2252 The 'thread apply' command accepts new FLAG arguments.
2253 FLAG arguments allow to control what output to produce and how to handle
2254 errors raised when applying COMMAND to a thread.
2256 set tui tab-width NCHARS
2257 show tui tab-width NCHARS
2258 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
2260 set style enabled [on|off]
2262 Enable or disable terminal styling. Styling is enabled by default
2263 on most hosts, but disabled by default when in batch mode.
2265 set style sources [on|off]
2267 Enable or disable source code styling. Source code styling is
2268 enabled by default, but only takes effect if styling in general is
2269 enabled, and if GDB was linked with GNU Source Highlight.
2271 set style filename foreground COLOR
2272 set style filename background COLOR
2273 set style filename intensity VALUE
2274 Control the styling of file names.
2276 set style function foreground COLOR
2277 set style function background COLOR
2278 set style function intensity VALUE
2279 Control the styling of function names.
2281 set style variable foreground COLOR
2282 set style variable background COLOR
2283 set style variable intensity VALUE
2284 Control the styling of variable names.
2286 set style address foreground COLOR
2287 set style address background COLOR
2288 set style address intensity VALUE
2289 Control the styling of addresses.
2293 ** The '-data-disassemble' MI command now accepts an '-a' option to
2294 disassemble the whole function surrounding the given program
2295 counter value or function name. Support for this feature can be
2296 verified by using the "-list-features" command, which should
2297 contain "data-disassemble-a-option".
2299 ** Command responses and notifications that include a frame now include
2300 the frame's architecture in a new "arch" attribute.
2302 * New native configurations
2304 GNU/Linux/RISC-V riscv*-*-linux*
2305 FreeBSD/riscv riscv*-*-freebsd*
2309 GNU/Linux/RISC-V riscv*-*-linux*
2310 CSKY ELF csky*-*-elf
2311 CSKY GNU/LINUX csky*-*-linux
2312 FreeBSD/riscv riscv*-*-freebsd*
2314 GNU/Linux/OpenRISC or1k*-*-linux*
2318 GDB no longer supports native debugging on versions of MS-Windows
2323 ** GDB no longer supports Python versions less than 2.6.
2325 ** The gdb.Inferior type has a new 'progspace' property, which is the program
2326 space associated to that inferior.
2328 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2329 of objfiles associated to that program space.
2331 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2332 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2335 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2336 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
2337 correct and did not work properly.
2339 ** The gdb.Value type has a new constructor, which is used to construct a
2340 gdb.Value from a Python buffer object and a gdb.Type.
2346 Enable or disable the undefined behavior sanitizer. This is
2347 disabled by default, but passing --enable-ubsan=yes or
2348 --enable-ubsan=auto to configure will enable it. Enabling this can
2349 cause a performance penalty. The undefined behavior sanitizer was
2350 first introduced in GCC 4.9.
2352 *** Changes in GDB 8.2
2354 * The 'set disassembler-options' command now supports specifying options
2355 for the MIPS target.
2357 * The 'symbol-file' command now accepts an '-o' option to add a relative
2358 offset to all sections.
2360 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2361 a relative offset to all sections, but it allows to override the load
2362 address of individual sections using '-s'.
2364 * The 'add-symbol-file' command no longer requires the second argument
2365 (address of the text section).
2367 * The endianness used with the 'set endian auto' mode in the absence of
2368 an executable selected for debugging is now the last endianness chosen
2369 either by one of the 'set endian big' and 'set endian little' commands
2370 or by inferring from the last executable used, rather than the startup
2373 * The pager now allows a "c" response, meaning to disable the pager
2374 for the rest of the current command.
2376 * The commands 'info variables/functions/types' now show the source line
2377 numbers of symbol definitions when available.
2379 * 'info proc' now works on running processes on FreeBSD systems and core
2380 files created on FreeBSD systems.
2382 * C expressions can now use _Alignof, and C++ expressions can now use
2385 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
2386 the vector length while the process is running.
2392 Control display of debugging info regarding the FreeBSD native target.
2394 set|show varsize-limit
2395 This new setting allows the user to control the maximum size of Ada
2396 objects being printed when those objects have a variable type,
2397 instead of that maximum size being hardcoded to 65536 bytes.
2399 set|show record btrace cpu
2400 Controls the processor to be used for enabling errata workarounds for
2401 branch trace decode.
2403 maint check libthread-db
2404 Run integrity checks on the current inferior's thread debugging
2407 maint set check-libthread-db (on|off)
2408 maint show check-libthread-db
2409 Control whether to run integrity checks on inferior specific thread
2410 debugging libraries as they are loaded. The default is not to
2411 perform such checks.
2415 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2417 ** The commands attached to a breakpoint can be set by assigning to
2418 the breakpoint's "commands" field.
2420 ** gdb.execute can now execute multi-line gdb commands.
2422 ** The new functions gdb.convenience_variable and
2423 gdb.set_convenience_variable can be used to get and set the value
2424 of convenience variables.
2426 ** A gdb.Parameter will no longer print the "set" help text on an
2427 ordinary "set"; instead by default a "set" will be silent unless
2428 the get_set_string method returns a non-empty string.
2432 RiscV ELF riscv*-*-elf
2434 * Removed targets and native configurations
2436 m88k running OpenBSD m88*-*-openbsd*
2437 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2438 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2439 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2441 * Aarch64/Linux hardware watchpoints improvements
2443 Hardware watchpoints on unaligned addresses are now properly
2444 supported when running Linux kernel 4.10 or higher: read and access
2445 watchpoints are no longer spuriously missed, and all watchpoints
2446 lengths between 1 and 8 bytes are supported. On older kernels,
2447 watchpoints set on unaligned addresses are no longer missed, with
2448 the tradeoff that there is a possibility of false hits being
2453 --enable-codesign=CERT
2454 This can be used to invoke "codesign -s CERT" after building gdb.
2455 This option is useful on macOS, where code signing is required for
2456 gdb to work properly.
2458 --disable-gdbcli has been removed
2459 This is now silently accepted, but does nothing.
2461 *** Changes in GDB 8.1
2463 * GDB now supports dynamically creating arbitrary register groups specified
2464 in XML target descriptions. This allows for finer grain grouping of
2465 registers on systems with a large amount of registers.
2467 * The 'ptype' command now accepts a '/o' flag, which prints the
2468 offsets and sizes of fields in a struct, like the pahole(1) tool.
2470 * New "--readnever" command line option instructs GDB to not read each
2471 symbol file's symbolic debug information. This makes startup faster
2472 but at the expense of not being able to perform symbolic debugging.
2473 This option is intended for use cases where symbolic debugging will
2474 not be used, e.g., when you only need to dump the debuggee's core.
2476 * GDB now uses the GNU MPFR library, if available, to emulate target
2477 floating-point arithmetic during expression evaluation when the target
2478 uses different floating-point formats than the host. At least version
2479 3.1 of GNU MPFR is required.
2481 * GDB now supports access to the guarded-storage-control registers and the
2482 software-based guarded-storage broadcast control registers on IBM z14.
2484 * On Unix systems, GDB now supports transmitting environment variables
2485 that are to be set or unset to GDBserver. These variables will
2486 affect the environment to be passed to the remote inferior.
2488 To inform GDB of environment variables that are to be transmitted to
2489 GDBserver, use the "set environment" command. Only user set
2490 environment variables are sent to GDBserver.
2492 To inform GDB of environment variables that are to be unset before
2493 the remote inferior is started by the GDBserver, use the "unset
2494 environment" command.
2496 * Completion improvements
2498 ** GDB can now complete function parameters in linespecs and
2499 explicit locations without quoting. When setting breakpoints,
2500 quoting around functions names to help with TAB-completion is
2501 generally no longer necessary. For example, this now completes
2504 (gdb) b function(in[TAB]
2505 (gdb) b function(int)
2507 Related, GDB is no longer confused with completing functions in
2508 C++ anonymous namespaces:
2511 (gdb) b (anonymous namespace)::[TAB][TAB]
2512 (anonymous namespace)::a_function()
2513 (anonymous namespace)::b_function()
2515 ** GDB now has much improved linespec and explicit locations TAB
2516 completion support, that better understands what you're
2517 completing and offers better suggestions. For example, GDB no
2518 longer offers data symbols as possible completions when you're
2519 setting a breakpoint.
2521 ** GDB now TAB-completes label symbol names.
2523 ** The "complete" command now mimics TAB completion accurately.
2525 * New command line options (gcore)
2528 Dump all memory mappings.
2530 * Breakpoints on C++ functions are now set on all scopes by default
2532 By default, breakpoints on functions/methods are now interpreted as
2533 specifying all functions with the given name ignoring missing
2534 leading scopes (namespaces and classes).
2536 For example, assuming a C++ program with symbols named:
2541 both commands "break func()" and "break B::func()" set a breakpoint
2544 You can use the new flag "-qualified" to override this. This makes
2545 GDB interpret the specified function name as a complete
2546 fully-qualified name instead. For example, using the same C++
2547 program, the "break -q B::func" command sets a breakpoint on
2548 "B::func", only. A parameter has been added to the Python
2549 gdb.Breakpoint constructor to achieve the same result when creating
2550 a breakpoint from Python.
2552 * Breakpoints on functions marked with C++ ABI tags
2554 GDB can now set breakpoints on functions marked with C++ ABI tags
2555 (e.g., [abi:cxx11]). See here for a description of ABI tags:
2556 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2558 Functions with a C++11 abi tag are demangled/displayed like this:
2560 function[abi:cxx11](int)
2563 You can now set a breakpoint on such functions simply as if they had
2566 (gdb) b function(int)
2568 Or if you need to disambiguate between tags, like:
2570 (gdb) b function[abi:other_tag](int)
2572 Tab completion was adjusted accordingly as well.
2576 ** New events gdb.new_inferior, gdb.inferior_deleted, and
2577 gdb.new_thread are emitted. See the manual for further
2578 description of these.
2580 ** A new function, "gdb.rbreak" has been added to the Python API.
2581 This function allows the setting of a large number of breakpoints
2582 via a regex pattern in Python. See the manual for further details.
2584 ** Python breakpoints can now accept explicit locations. See the
2585 manual for a further description of this feature.
2588 * New features in the GDB remote stub, GDBserver
2590 ** GDBserver is now able to start inferior processes with a
2591 specified initial working directory.
2593 The user can set the desired working directory to be used from
2594 GDB using the new "set cwd" command.
2596 ** New "--selftest" command line option runs some GDBserver self
2597 tests. These self tests are disabled in releases.
2599 ** On Unix systems, GDBserver now does globbing expansion and variable
2600 substitution in inferior command line arguments.
2602 This is done by starting inferiors using a shell, like GDB does.
2603 See "set startup-with-shell" in the user manual for how to disable
2604 this from GDB when using "target extended-remote". When using
2605 "target remote", you can disable the startup with shell by using the
2606 new "--no-startup-with-shell" GDBserver command line option.
2608 ** On Unix systems, GDBserver now supports receiving environment
2609 variables that are to be set or unset from GDB. These variables
2610 will affect the environment to be passed to the inferior.
2612 * When catching an Ada exception raised with a message, GDB now prints
2613 the message in the catchpoint hit notification. In GDB/MI mode, that
2614 information is provided as an extra field named "exception-message"
2615 in the *stopped notification.
2617 * Trait objects can now be inspected When debugging Rust code. This
2618 requires compiler support which will appear in Rust 1.24.
2620 * New remote packets
2622 QEnvironmentHexEncoded
2623 Inform GDBserver of an environment variable that is to be passed to
2624 the inferior when starting it.
2627 Inform GDBserver of an environment variable that is to be unset
2628 before starting the remote inferior.
2631 Inform GDBserver that the environment should be reset (i.e.,
2632 user-set environment variables should be unset).
2635 Indicates whether the inferior must be started with a shell or not.
2638 Tell GDBserver that the inferior to be started should use a specific
2641 * The "maintenance print c-tdesc" command now takes an optional
2642 argument which is the file name of XML target description.
2644 * The "maintenance selftest" command now takes an optional argument to
2645 filter the tests to be run.
2647 * The "enable", and "disable" commands now accept a range of
2648 breakpoint locations, e.g. "enable 1.3-5".
2653 Set and show the current working directory for the inferior.
2655 set|show compile-gcc
2656 Set and show compilation command used for compiling and injecting code
2657 with the 'compile' commands.
2659 set debug separate-debug-file
2660 show debug separate-debug-file
2661 Control the display of debug output about separate debug file search.
2663 set dump-excluded-mappings
2664 show dump-excluded-mappings
2665 Control whether mappings marked with the VM_DONTDUMP flag should be
2666 dumped when generating a core file.
2668 maint info selftests
2669 List the registered selftests.
2672 Start the debugged program stopping at the first instruction.
2675 Control display of debugging messages related to OpenRISC targets.
2677 set|show print type nested-type-limit
2678 Set and show the limit of nesting level for nested types that the
2679 type printer will show.
2681 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2684 * Safer/improved support for debugging with no debug info
2686 GDB no longer assumes functions with no debug information return
2689 This means that GDB now refuses to call such functions unless you
2690 tell it the function's type, by either casting the call to the
2691 declared return type, or by casting the function to a function
2692 pointer of the right type, and calling that:
2694 (gdb) p getenv ("PATH")
2695 'getenv' has unknown return type; cast the call to its declared return type
2696 (gdb) p (char *) getenv ("PATH")
2697 $1 = 0x7fffffffe "/usr/local/bin:/"...
2698 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2699 $2 = 0x7fffffffe "/usr/local/bin:/"...
2701 Similarly, GDB no longer assumes that global variables with no debug
2702 info have type 'int', and refuses to print the variable's value
2703 unless you tell it the variable's type:
2706 'var' has unknown type; cast it to its declared type
2710 * New native configurations
2712 FreeBSD/aarch64 aarch64*-*-freebsd*
2713 FreeBSD/arm arm*-*-freebsd*
2717 FreeBSD/aarch64 aarch64*-*-freebsd*
2718 FreeBSD/arm arm*-*-freebsd*
2719 OpenRISC ELF or1k*-*-elf
2721 * Removed targets and native configurations
2723 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2725 *** Changes in GDB 8.0
2727 * GDB now supports access to the PKU register on GNU/Linux. The register is
2728 added by the Memory Protection Keys for Userspace feature which will be
2729 available in future Intel CPUs.
2731 * GDB now supports C++11 rvalue references.
2735 ** New functions to start, stop and access a running btrace recording.
2736 ** Rvalue references are now supported in gdb.Type.
2738 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2741 * Building GDB and GDBserver now requires a C++11 compiler.
2743 For example, GCC 4.8 or later.
2745 It is no longer possible to build GDB or GDBserver with a C
2746 compiler. The --disable-build-with-cxx configure option has been
2749 * Building GDB and GDBserver now requires GNU make >= 3.81.
2751 It is no longer supported to build GDB or GDBserver with another
2752 implementation of the make program or an earlier version of GNU make.
2754 * Native debugging on MS-Windows supports command-line redirection
2756 Command-line arguments used for starting programs on MS-Windows can
2757 now include redirection symbols supported by native Windows shells,
2758 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2759 as "run", "start", and "set args", as well as the corresponding MI
2762 * Support for thread names on MS-Windows.
2764 GDB now catches and handles the special exception that programs
2765 running on MS-Windows use to assign names to threads in the
2768 * Support for Java programs compiled with gcj has been removed.
2770 * User commands now accept an unlimited number of arguments.
2771 Previously, only up to 10 was accepted.
2773 * The "eval" command now expands user-defined command arguments.
2775 This makes it easier to process a variable number of arguments:
2780 eval "print $arg%d", $i
2785 * Target descriptions can now describe registers for sparc32 and sparc64.
2787 * GDB now supports DWARF version 5 (debug information format).
2788 Its .debug_names index is not yet supported.
2790 * New native configurations
2792 FreeBSD/mips mips*-*-freebsd
2796 Synopsys ARC arc*-*-elf32
2797 FreeBSD/mips mips*-*-freebsd
2799 * Removed targets and native configurations
2801 Alpha running FreeBSD alpha*-*-freebsd*
2802 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2807 Erases all the flash memory regions reported by the target.
2809 maint print arc arc-instruction address
2810 Print internal disassembler information about instruction at a given address.
2814 set disassembler-options
2815 show disassembler-options
2816 Controls the passing of target specific information to the disassembler.
2817 If it is necessary to specify more than one disassembler option then
2818 multiple options can be placed together into a comma separated list.
2819 The default value is the empty string. Currently, the only supported
2820 targets are ARM, PowerPC and S/390.
2825 Erases all the flash memory regions reported by the target. This is
2826 equivalent to the CLI command flash-erase.
2828 -file-list-shared-libraries
2829 List the shared libraries in the program. This is
2830 equivalent to the CLI command "info shared".
2833 Catchpoints stopping the program when Ada exceptions are
2834 handled. This is equivalent to the CLI command "catch handlers".
2836 *** Changes in GDB 7.12
2838 * GDB and GDBserver now build with a C++ compiler by default.
2840 The --enable-build-with-cxx configure option is now enabled by
2841 default. One must now explicitly configure with
2842 --disable-build-with-cxx in order to build with a C compiler. This
2843 option will be removed in a future release.
2845 * GDBserver now supports recording btrace without maintaining an active
2848 * GDB now supports a negative repeat count in the 'x' command to examine
2849 memory backward from the given address. For example:
2852 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2853 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2854 (gdb) x/-5i 0x0000000000400580
2855 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2856 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2857 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2858 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2859 0x40057b <main(int, char**)+25>:
2860 callq 0x400536 <Func1(int, char const*)>
2862 * Fortran: Support structures with fields of dynamic types and
2863 arrays of dynamic types.
2865 * The symbol dumping maintenance commands have new syntax.
2866 maint print symbols [-pc address] [--] [filename]
2867 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2868 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2869 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2870 maint print msymbols [-objfile objfile] [--] [filename]
2872 * GDB now supports multibit bitfields and enums in target register
2875 * New Python-based convenience function $_as_string(val), which returns
2876 the textual representation of a value. This function is especially
2877 useful to obtain the text label of an enum value.
2879 * Intel MPX bound violation handling.
2881 Segmentation faults caused by a Intel MPX boundary violation
2882 now display the kind of violation (upper or lower), the memory
2883 address accessed and the memory bounds, along with the usual
2884 signal received and code location.
2888 Program received signal SIGSEGV, Segmentation fault
2889 Upper bound violation while accessing address 0x7fffffffc3b3
2890 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2891 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2893 * Rust language support.
2894 GDB now supports debugging programs written in the Rust programming
2895 language. See https://www.rust-lang.org/ for more information about
2898 * Support for running interpreters on specified input/output devices
2900 GDB now supports a new mechanism that allows frontends to provide
2901 fully featured GDB console views, as a better alternative to
2902 building such views on top of the "-interpreter-exec console"
2903 command. See the new "new-ui" command below. With that command,
2904 frontends can now start GDB in the traditional command-line mode
2905 running in an embedded terminal emulator widget, and create a
2906 separate MI interpreter running on a specified i/o device. In this
2907 way, GDB handles line editing, history, tab completion, etc. in the
2908 console all by itself, and the GUI uses the separate MI interpreter
2909 for its own control and synchronization, invisible to the command
2912 * The "catch syscall" command catches groups of related syscalls.
2914 The "catch syscall" command now supports catching a group of related
2915 syscalls using the 'group:' or 'g:' prefix.
2920 skip -gfile file-glob-pattern
2921 skip -function function
2922 skip -rfunction regular-expression
2923 A generalized form of the skip command, with new support for
2924 glob-style file names and regular expressions for function names.
2925 Additionally, a file spec and a function spec may now be combined.
2927 maint info line-table REGEXP
2928 Display the contents of GDB's internal line table data structure.
2931 Run any GDB unit tests that were compiled in.
2934 Start a new user interface instance running INTERP as interpreter,
2935 using the TTY file for input/output.
2939 ** gdb.Breakpoint objects have a new attribute "pending", which
2940 indicates whether the breakpoint is pending.
2941 ** Three new breakpoint-related events have been added:
2942 gdb.breakpoint_created, gdb.breakpoint_modified, and
2943 gdb.breakpoint_deleted.
2945 signal-event EVENTID
2946 Signal ("set") the given MS-Windows event object. This is used in
2947 conjunction with the Windows JIT debugging (AeDebug) support, where
2948 the OS suspends a crashing process until a debugger can attach to
2949 it. Resuming the crashing process, in order to debug it, is done by
2950 signalling an event.
2952 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2953 was added in GDBserver, including JIT compiling fast tracepoint's
2954 conditional expression bytecode into native code.
2956 * Support for various remote target protocols and ROM monitors has
2959 target m32rsdi Remote M32R debugging over SDI
2960 target mips MIPS remote debugging protocol
2961 target pmon PMON ROM monitor
2962 target ddb NEC's DDB variant of PMON for Vr4300
2963 target rockhopper NEC RockHopper variant of PMON
2964 target lsi LSI variant of PMO
2966 * Support for tracepoints and fast tracepoints on powerpc-linux,
2967 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2968 including JIT compiling fast tracepoint's conditional expression
2969 bytecode into native code.
2971 * MI async record =record-started now includes the method and format used for
2972 recording. For example:
2974 =record-started,thread-group="i1",method="btrace",format="bts"
2976 * MI async record =thread-selected now includes the frame field. For example:
2978 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2982 Andes NDS32 nds32*-*-elf
2984 *** Changes in GDB 7.11
2986 * GDB now supports debugging kernel-based threads on FreeBSD.
2988 * Per-inferior thread numbers
2990 Thread numbers are now per inferior instead of global. If you're
2991 debugging multiple inferiors, GDB displays thread IDs using a
2992 qualified INF_NUM.THR_NUM form. For example:
2996 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2997 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2998 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2999 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
3001 As consequence, thread numbers as visible in the $_thread
3002 convenience variable and in Python's InferiorThread.num attribute
3003 are no longer unique between inferiors.
3005 GDB now maintains a second thread ID per thread, referred to as the
3006 global thread ID, which is the new equivalent of thread numbers in
3007 previous releases. See also $_gthread below.
3009 For backwards compatibility, MI's thread IDs always refer to global
3012 * Commands that accept thread IDs now accept the qualified
3013 INF_NUM.THR_NUM form as well. For example:
3016 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
3019 * In commands that accept a list of thread IDs, you can now refer to
3020 all threads of an inferior using a star wildcard. GDB accepts
3021 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
3022 refer to all threads of the current inferior. For example, "info
3025 * You can use "info threads -gid" to display the global thread ID of
3028 * The new convenience variable $_gthread holds the global number of
3031 * The new convenience variable $_inferior holds the number of the
3034 * GDB now displays the ID and name of the thread that hit a breakpoint
3035 or received a signal, if your program is multi-threaded. For
3038 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
3039 Thread 1 "main" received signal SIGINT, Interrupt.
3041 * Record btrace now supports non-stop mode.
3043 * Support for tracepoints on aarch64-linux was added in GDBserver.
3045 * The 'record instruction-history' command now indicates speculative execution
3046 when using the Intel Processor Trace recording format.
3048 * GDB now allows users to specify explicit locations, bypassing
3049 the linespec parser. This feature is also available to GDB/MI
3052 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
3053 GDB now is able to debug both AArch64 applications and ARM applications
3056 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
3057 including JIT compiling fast tracepoint's conditional expression bytecode
3060 * GDB now supports displaced stepping on AArch64 GNU/Linux.
3062 * "info threads", "info inferiors", "info display", "info checkpoints"
3063 and "maint info program-spaces" now list the corresponding items in
3064 ascending ID order, for consistency with all other "info" commands.
3066 * In Ada, the overloads selection menu has been enhanced to display the
3067 parameter types and the return types for the matching overloaded subprograms.
3071 maint set target-non-stop (on|off|auto)
3072 maint show target-non-stop
3073 Control whether GDB targets always operate in non-stop mode even if
3074 "set non-stop" is "off". The default is "auto", meaning non-stop
3075 mode is enabled if supported by the target.
3077 maint set bfd-sharing
3078 maint show bfd-sharing
3079 Control the reuse of bfd objects.
3082 show debug bfd-cache
3083 Control display of debugging info regarding bfd caching.
3087 Control display of debugging info regarding FreeBSD threads.
3089 set remote multiprocess-extensions-packet
3090 show remote multiprocess-extensions-packet
3091 Set/show the use of the remote protocol multiprocess extensions.
3093 set remote thread-events
3094 show remote thread-events
3095 Set/show the use of thread create/exit events.
3097 set ada print-signatures on|off
3098 show ada print-signatures"
3099 Control whether parameter types and return types are displayed in overloads
3100 selection menus. It is activated (@code{on}) by default.
3104 Controls the maximum size of memory, in bytes, that GDB will
3105 allocate for value contents. Prevents incorrect programs from
3106 causing GDB to allocate overly large buffers. Default is 64k.
3108 * The "disassemble" command accepts a new modifier: /s.
3109 It prints mixed source+disassembly like /m with two differences:
3110 - disassembled instructions are now printed in program order, and
3111 - and source for all relevant files is now printed.
3112 The "/m" option is now considered deprecated: its "source-centric"
3113 output hasn't proved useful in practice.
3115 * The "record instruction-history" command accepts a new modifier: /s.
3116 It behaves exactly like /m and prints mixed source+disassembly.
3118 * The "set scheduler-locking" command supports a new mode "replay".
3119 It behaves like "off" in record mode and like "on" in replay mode.
3121 * Support for various ROM monitors has been removed:
3123 target dbug dBUG ROM monitor for Motorola ColdFire
3124 target picobug Motorola picobug monitor
3125 target dink32 DINK32 ROM monitor for PowerPC
3126 target m32r Renesas M32R/D ROM monitor
3127 target mon2000 mon2000 ROM monitor
3128 target ppcbug PPCBUG ROM monitor for PowerPC
3130 * Support for reading/writing memory and extracting values on architectures
3131 whose memory is addressable in units of any integral multiple of 8 bits.
3134 Allows to break when an Ada exception is handled.
3136 * New remote packets
3139 Indicates that an exec system call was executed.
3141 exec-events feature in qSupported
3142 The qSupported packet allows GDB to request support for exec
3143 events using the new 'gdbfeature' exec-event, and the qSupported
3144 response can contain the corresponding 'stubfeature'. Set and
3145 show commands can be used to display whether these features are enabled.
3148 Equivalent to interrupting with the ^C character, but works in
3151 thread created stop reason (T05 create:...)
3152 Indicates that the thread was just created and is stopped at entry.
3154 thread exit stop reply (w exitcode;tid)
3155 Indicates that the thread has terminated.
3158 Enables/disables thread create and exit event reporting. For
3159 example, this is used in non-stop mode when GDB stops a set of
3160 threads and synchronously waits for the their corresponding stop
3161 replies. Without exit events, if one of the threads exits, GDB
3162 would hang forever not knowing that it should no longer expect a
3163 stop for that same thread.
3166 Indicates that there are no resumed threads left in the target (all
3167 threads are stopped). The remote stub reports support for this stop
3168 reply to GDB's qSupported query.
3171 Enables/disables catching syscalls from the inferior process.
3172 The remote stub reports support for this packet to GDB's qSupported query.
3174 syscall_entry stop reason
3175 Indicates that a syscall was just called.
3177 syscall_return stop reason
3178 Indicates that a syscall just returned.
3180 * Extended-remote exec events
3182 ** GDB now has support for exec events on extended-remote Linux targets.
3183 For such targets with Linux kernels 2.5.46 and later, this enables
3184 follow-exec-mode and exec catchpoints.
3186 set remote exec-event-feature-packet
3187 show remote exec-event-feature-packet
3188 Set/show the use of the remote exec event feature.
3190 * Thread names in remote protocol
3192 The reply to qXfer:threads:read may now include a name attribute for each
3195 * Target remote mode fork and exec events
3197 ** GDB now has support for fork and exec events on target remote mode
3198 Linux targets. For such targets with Linux kernels 2.5.46 and later,
3199 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
3200 fork and exec catchpoints.
3202 * Remote syscall events
3204 ** GDB now has support for catch syscall on remote Linux targets,
3205 currently enabled on x86/x86_64 architectures.
3207 set remote catch-syscall-packet
3208 show remote catch-syscall-packet
3209 Set/show the use of the remote catch syscall feature.
3213 ** The -var-set-format command now accepts the zero-hexadecimal
3214 format. It outputs data in hexadecimal format with zero-padding on the
3219 ** gdb.InferiorThread objects have a new attribute "global_num",
3220 which refers to the thread's global thread ID. The existing
3221 "num" attribute now refers to the thread's per-inferior number.
3222 See "Per-inferior thread numbers" above.
3223 ** gdb.InferiorThread objects have a new attribute "inferior", which
3224 is the Inferior object the thread belongs to.
3226 *** Changes in GDB 7.10
3228 * Support for process record-replay and reverse debugging on aarch64*-linux*
3229 targets has been added. GDB now supports recording of A64 instruction set
3230 including advance SIMD instructions.
3232 * Support for Sun's version of the "stabs" debug file format has been removed.
3234 * GDB now honors the content of the file /proc/PID/coredump_filter
3235 (PID is the process ID) on GNU/Linux systems. This file can be used
3236 to specify the types of memory mappings that will be included in a
3237 corefile. For more information, please refer to the manual page of
3238 "core(5)". GDB also has a new command: "set use-coredump-filter
3239 on|off". It allows to set whether GDB will read the content of the
3240 /proc/PID/coredump_filter file when generating a corefile.
3242 * The "info os" command on GNU/Linux can now display information on
3244 "info os cpus" Listing of all cpus/cores on the system
3246 * GDB has two new commands: "set serial parity odd|even|none" and
3247 "show serial parity". These allows to set or show parity for the
3250 * The "info source" command now displays the producer string if it was
3251 present in the debug info. This typically includes the compiler version
3252 and may include things like its command line arguments.
3254 * The "info dll", an alias of the "info sharedlibrary" command,
3255 is now available on all platforms.
3257 * Directory names supplied to the "set sysroot" commands may be
3258 prefixed with "target:" to tell GDB to access shared libraries from
3259 the target system, be it local or remote. This replaces the prefix
3260 "remote:". The default sysroot has been changed from "" to
3261 "target:". "remote:" is automatically converted to "target:" for
3262 backward compatibility.
3264 * The system root specified by "set sysroot" will be prepended to the
3265 filename of the main executable (if reported to GDB as absolute by
3266 the operating system) when starting processes remotely, and when
3267 attaching to already-running local or remote processes.
3269 * GDB now supports automatic location and retrieval of executable
3270 files from remote targets. Remote debugging can now be initiated
3271 using only a "target remote" or "target extended-remote" command
3272 (no "set sysroot" or "file" commands are required). See "New remote
3275 * The "dump" command now supports verilog hex format.
3277 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
3279 * On GNU/Linux, GDB and gdbserver are now able to access executable
3280 and shared library files without a "set sysroot" command when
3281 attaching to processes running in different mount namespaces from
3282 the debugger. This makes it possible to attach to processes in
3283 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
3284 See "New remote packets" below.
3286 * The "tui reg" command now provides completion for all of the
3287 available register groups, including target specific groups.
3289 * The HISTSIZE environment variable is no longer read when determining
3290 the size of GDB's command history. GDB now instead reads the dedicated
3291 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
3292 disables truncation of command history. Non-numeric values of GDBHISTSIZE
3297 ** Memory ports can now be unbuffered.
3301 ** gdb.Objfile objects have a new attribute "username",
3302 which is the name of the objfile as specified by the user,
3303 without, for example, resolving symlinks.
3304 ** You can now write frame unwinders in Python.
3305 ** gdb.Type objects have a new method "optimized_out",
3306 returning optimized out gdb.Value instance of this type.
3307 ** gdb.Value objects have new methods "reference_value" and
3308 "const_value" which return a reference to the value and a
3309 "const" version of the value respectively.
3313 maint print symbol-cache
3314 Print the contents of the symbol cache.
3316 maint print symbol-cache-statistics
3317 Print statistics of symbol cache usage.
3319 maint flush-symbol-cache
3320 Flush the contents of the symbol cache.
3324 Start branch trace recording using Branch Trace Store (BTS) format.
3327 Evaluate expression by using the compiler and print result.
3331 Explicit commands for enabling and disabling tui mode.
3334 set mpx bound on i386 and amd64
3335 Support for bound table investigation on Intel MPX enabled applications.
3339 Start branch trace recording using Intel Processor Trace format.
3342 Print information about branch tracing internals.
3344 maint btrace packet-history
3345 Print the raw branch tracing data.
3347 maint btrace clear-packet-history
3348 Discard the stored raw branch tracing data.
3351 Discard all branch tracing data. It will be fetched and processed
3352 anew by the next "record" command.
3357 Renamed from "set debug dwarf2-die".
3358 show debug dwarf-die
3359 Renamed from "show debug dwarf2-die".
3361 set debug dwarf-read
3362 Renamed from "set debug dwarf2-read".
3363 show debug dwarf-read
3364 Renamed from "show debug dwarf2-read".
3366 maint set dwarf always-disassemble
3367 Renamed from "maint set dwarf2 always-disassemble".
3368 maint show dwarf always-disassemble
3369 Renamed from "maint show dwarf2 always-disassemble".
3371 maint set dwarf max-cache-age
3372 Renamed from "maint set dwarf2 max-cache-age".
3373 maint show dwarf max-cache-age
3374 Renamed from "maint show dwarf2 max-cache-age".
3376 set debug dwarf-line
3377 show debug dwarf-line
3378 Control display of debugging info regarding DWARF line processing.
3381 show max-completions
3382 Set the maximum number of candidates to be considered during
3383 completion. The default value is 200. This limit allows GDB
3384 to avoid generating large completion lists, the computation of
3385 which can cause the debugger to become temporarily unresponsive.
3387 set history remove-duplicates
3388 show history remove-duplicates
3389 Control the removal of duplicate history entries.
3391 maint set symbol-cache-size
3392 maint show symbol-cache-size
3393 Control the size of the symbol cache.
3395 set|show record btrace bts buffer-size
3396 Set and show the size of the ring buffer used for branch tracing in
3398 The obtained size may differ from the requested size. Use "info
3399 record" to see the obtained buffer size.
3401 set debug linux-namespaces
3402 show debug linux-namespaces
3403 Control display of debugging info regarding Linux namespaces.
3405 set|show record btrace pt buffer-size
3406 Set and show the size of the ring buffer used for branch tracing in
3407 Intel Processor Trace format.
3408 The obtained size may differ from the requested size. Use "info
3409 record" to see the obtained buffer size.
3411 maint set|show btrace pt skip-pad
3412 Set and show whether PAD packets are skipped when computing the
3415 * The command 'thread apply all' can now support new option '-ascending'
3416 to call its specified command for all threads in ascending order.
3418 * Python/Guile scripting
3420 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3421 special section named `.debug_gdb_scripts'.
3423 * New remote packets
3425 qXfer:btrace-conf:read
3426 Return the branch trace configuration for the current thread.
3428 Qbtrace-conf:bts:size
3429 Set the requested ring buffer size for branch tracing in BTS format.
3432 Enable Intel Processor Trace-based branch tracing for the current
3433 process. The remote stub reports support for this packet to GDB's
3436 Qbtrace-conf:pt:size
3437 Set the requested ring buffer size for branch tracing in Intel Processor
3441 Indicates a memory breakpoint instruction was executed, irrespective
3442 of whether it was GDB that planted the breakpoint or the breakpoint
3443 is hardcoded in the program. This is required for correct non-stop
3447 Indicates the target stopped for a hardware breakpoint. This is
3448 required for correct non-stop mode operation.
3451 Return information about files on the remote system.
3453 qXfer:exec-file:read
3454 Return the full absolute name of the file that was executed to
3455 create a process running on the remote system.
3458 Select the filesystem on which vFile: operations with filename
3459 arguments will operate. This is required for GDB to be able to
3460 access files on remote targets where the remote stub does not
3461 share a common filesystem with the inferior(s).
3464 Indicates that a fork system call was executed.
3467 Indicates that a vfork system call was executed.
3469 vforkdone stop reason
3470 Indicates that a vfork child of the specified process has executed
3471 an exec or exit, allowing the vfork parent to resume execution.
3473 fork-events and vfork-events features in qSupported
3474 The qSupported packet allows GDB to request support for fork and
3475 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3476 and the qSupported response can contain the corresponding
3477 'stubfeatures'. Set and show commands can be used to display
3478 whether these features are enabled.
3480 * Extended-remote fork events
3482 ** GDB now has support for fork events on extended-remote Linux
3483 targets. For targets with Linux kernels 2.5.60 and later, this
3484 enables follow-fork-mode and detach-on-fork for both fork and
3485 vfork, as well as fork and vfork catchpoints.
3487 * The info record command now shows the recording format and the
3488 branch tracing configuration for the current thread when using
3489 the btrace record target.
3490 For the BTS format, it shows the ring buffer size.
3492 * GDB now has support for DTrace USDT (Userland Static Defined
3493 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3495 * GDB now supports access to vector registers on S/390 GNU/Linux
3498 * Removed command line options
3500 -xdb HP-UX XDB compatibility mode.
3502 * Removed targets and native configurations
3504 HP/PA running HP-UX hppa*-*-hpux*
3505 Itanium running HP-UX ia64-*-hpux*
3507 * New configure options
3510 This configure option allows the user to build GDB with support for
3511 Intel Processor Trace (default: auto). This requires libipt.
3513 --with-libipt-prefix=PATH
3514 Specify the path to the version of libipt that GDB should use.
3515 $PATH/include should contain the intel-pt.h header and
3516 $PATH/lib should contain the libipt.so library.
3518 *** Changes in GDB 7.9.1
3522 ** Xmethods can now specify a result type.
3524 *** Changes in GDB 7.9
3526 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3530 ** You can now access frame registers from Python scripts.
3531 ** New attribute 'producer' for gdb.Symtab objects.
3532 ** gdb.Objfile objects have a new attribute "progspace",
3533 which is the gdb.Progspace object of the containing program space.
3534 ** gdb.Objfile objects have a new attribute "owner".
3535 ** gdb.Objfile objects have a new attribute "build_id",
3536 which is the build ID generated when the file was built.
3537 ** gdb.Objfile objects have a new method "add_separate_debug_file".
3538 ** A new event "gdb.clear_objfiles" has been added, triggered when
3539 selecting a new file to debug.
3540 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3541 ** New function gdb.lookup_objfile.
3543 New events which are triggered when GDB modifies the state of the
3546 ** gdb.events.inferior_call_pre: Function call is about to be made.
3547 ** gdb.events.inferior_call_post: Function call has just been made.
3548 ** gdb.events.memory_changed: A memory location has been altered.
3549 ** gdb.events.register_changed: A register has been altered.
3551 * New Python-based convenience functions:
3553 ** $_caller_is(name [, number_of_frames])
3554 ** $_caller_matches(regexp [, number_of_frames])
3555 ** $_any_caller_is(name [, number_of_frames])
3556 ** $_any_caller_matches(regexp [, number_of_frames])
3558 * GDB now supports the compilation and injection of source code into
3559 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
3560 to compile the source code to object code, and if successful, inject
3561 and execute that code within the current context of the inferior.
3562 Currently the C language is supported. The commands used to
3563 interface with this new feature are:
3565 compile code [-raw|-r] [--] [source code]
3566 compile file [-raw|-r] filename
3570 demangle [-l language] [--] name
3571 Demangle "name" in the specified language, or the current language
3572 if elided. This command is renamed from the "maint demangle" command.
3573 The latter is kept as a no-op to avoid "maint demangle" being interpreted
3574 as "maint demangler-warning".
3576 queue-signal signal-name-or-number
3577 Queue a signal to be delivered to the thread when it is resumed.
3579 add-auto-load-scripts-directory directory
3580 Add entries to the list of directories from which to load auto-loaded
3583 maint print user-registers
3584 List all currently available "user" registers.
3586 compile code [-r|-raw] [--] [source code]
3587 Compile, inject, and execute in the inferior the executable object
3588 code produced by compiling the provided source code.
3590 compile file [-r|-raw] filename
3591 Compile and inject into the inferior the executable object code
3592 produced by compiling the source code stored in the filename
3595 * On resume, GDB now always passes the signal the program had stopped
3596 for to the thread the signal was sent to, even if the user changed
3597 threads before resuming. Previously GDB would often (but not
3598 always) deliver the signal to the thread that happens to be current
3601 * Conversely, the "signal" command now consistently delivers the
3602 requested signal to the current thread. GDB now asks for
3603 confirmation if the program had stopped for a signal and the user
3604 switched threads meanwhile.
3606 * "breakpoint always-inserted" modes "off" and "auto" merged.
3608 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3609 won't remove breakpoints from the target until all threads stop,
3610 even in non-stop mode. The "auto" mode has been removed, and "off"
3611 is now the default mode.
3615 set debug symbol-lookup
3616 show debug symbol-lookup
3617 Control display of debugging info regarding symbol lookup.
3621 ** The -list-thread-groups command outputs an exit-code field for
3622 inferiors that have exited.
3626 MIPS SDE mips*-sde*-elf*
3630 Support for these obsolete configurations has been removed.
3632 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
3633 SGI Irix-5.x mips-*-irix5*
3634 SGI Irix-6.x mips-*-irix6*
3635 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
3636 VAX running Ultrix vax-*-ultrix*
3638 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3639 and "assf"), have been removed. Use the "sharedlibrary" command, or
3640 its alias "share", instead.
3642 *** Changes in GDB 7.8
3644 * New command line options
3647 This is an alias for the --data-directory option.
3649 * GDB supports printing and modifying of variable length automatic arrays
3650 as specified in ISO C99.
3652 * The ARM simulator now supports instruction level tracing
3653 with or without disassembly.
3657 GDB now has support for scripting using Guile. Whether this is
3658 available is determined at configure time.
3659 Guile version 2.0 or greater is required.
3660 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3662 * New commands (for set/show, see "New options" below)
3666 Invoke CODE by passing it to the Guile interpreter.
3670 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3672 info auto-load guile-scripts [regexp]
3673 Print the list of automatically loaded Guile scripts.
3675 * The source command is now capable of sourcing Guile scripts.
3676 This feature is dependent on the debugger being built with Guile support.
3680 set print symbol-loading (off|brief|full)
3681 show print symbol-loading
3682 Control whether to print informational messages when loading symbol
3683 information for a file. The default is "full", but when debugging
3684 programs with large numbers of shared libraries the amount of output
3685 becomes less useful.
3687 set guile print-stack (none|message|full)
3688 show guile print-stack
3689 Show a stack trace when an error is encountered in a Guile script.
3691 set auto-load guile-scripts (on|off)
3692 show auto-load guile-scripts
3693 Control auto-loading of Guile script files.
3695 maint ada set ignore-descriptive-types (on|off)
3696 maint ada show ignore-descriptive-types
3697 Control whether the debugger should ignore descriptive types in Ada
3698 programs. The default is not to ignore the descriptive types. See
3699 the user manual for more details on descriptive types and the intended
3700 usage of this option.
3702 set auto-connect-native-target
3704 Control whether GDB is allowed to automatically connect to the
3705 native target for the run, attach, etc. commands when not connected
3706 to any target yet. See also "target native" below.
3708 set record btrace replay-memory-access (read-only|read-write)
3709 show record btrace replay-memory-access
3710 Control what memory accesses are allowed during replay.
3712 maint set target-async (on|off)
3713 maint show target-async
3714 This controls whether GDB targets operate in synchronous or
3715 asynchronous mode. Normally the default is asynchronous, if it is
3716 available; but this can be changed to more easily debug problems
3717 occurring only in synchronous mode.
3719 set mi-async (on|off)
3721 Control whether MI asynchronous mode is preferred. This supersedes
3722 "set target-async" of previous GDB versions.
3724 * "set target-async" is deprecated as a CLI option and is now an alias
3725 for "set mi-async" (only puts MI into async mode).
3727 * Background execution commands (e.g., "c&", "s&", etc.) are now
3728 possible ``out of the box'' if the target supports them. Previously
3729 the user would need to explicitly enable the possibility with the
3730 "set target-async on" command.
3732 * New features in the GDB remote stub, GDBserver
3734 ** New option --debug-format=option1[,option2,...] allows one to add
3735 additional text to each output. At present only timestamps
3736 are supported: --debug-format=timestamps.
3737 Timestamps can also be turned on with the
3738 "monitor set debug-format timestamps" command from GDB.
3740 * The 'record instruction-history' command now starts counting instructions
3741 at one. This also affects the instruction ranges reported by the
3742 'record function-call-history' command when given the /i modifier.
3744 * The command 'record function-call-history' supports a new modifier '/c' to
3745 indent the function names based on their call stack depth.
3746 The fields for the '/i' and '/l' modifier have been reordered.
3747 The source line range is now prefixed with 'at'.
3748 The instruction range is now prefixed with 'inst'.
3749 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3750 "record instruction-history" and "list" commands.
3752 * The ranges given as arguments to the 'record function-call-history' and
3753 'record instruction-history' commands are now inclusive.
3755 * The btrace record target now supports the 'record goto' command.
3756 For locations inside the execution trace, the back trace is computed
3757 based on the information stored in the execution trace.
3759 * The btrace record target supports limited reverse execution and replay.
3760 The target does not record data and therefore does not allow reading
3761 memory or registers.
3763 * The "catch syscall" command now works on s390*-linux* targets.
3765 * The "compare-sections" command is no longer specific to target
3766 remote. It now works with all targets.
3768 * All native targets are now consistently called "native".
3769 Consequently, the "target child", "target GNU", "target djgpp",
3770 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3771 commands have been replaced with "target native". The QNX/NTO port
3772 leaves the "procfs" target in place and adds a "native" target for
3773 consistency with other ports. The impact on users should be minimal
3774 as these commands previously either throwed an error, or were
3775 no-ops. The target's name is visible in the output of the following
3776 commands: "help target", "info target", "info files", "maint print
3779 * The "target native" command now connects to the native target. This
3780 can be used to launch native programs even when "set
3781 auto-connect-native-target" is set to off.
3783 * GDB now supports access to Intel MPX registers on GNU/Linux.
3785 * Support for Intel AVX-512 registers on GNU/Linux.
3786 Support displaying and modifying Intel AVX-512 registers
3787 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3789 * New remote packets
3791 qXfer:btrace:read's annex
3792 The qXfer:btrace:read packet supports a new annex 'delta' to read
3793 branch trace incrementally.
3797 ** Valid Python operations on gdb.Value objects representing
3798 structs/classes invoke the corresponding overloaded operators if
3800 ** New `Xmethods' feature in the Python API. Xmethods are
3801 additional methods or replacements for existing methods of a C++
3802 class. This feature is useful for those cases where a method
3803 defined in C++ source code could be inlined or optimized out by
3804 the compiler, making it unavailable to GDB.
3807 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3809 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3810 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3811 its alias "share", instead.
3813 * The commands "set remotebaud" and "show remotebaud" are no longer
3814 supported. Use "set serial baud" and "show serial baud" (respectively)
3819 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3820 target-async". The latter is left as a deprecated alias of the
3821 former for backward compatibility. If the target supports it,
3822 CLI background execution commands are now always possible by
3823 default, independently of whether the frontend stated a
3824 preference for asynchronous execution with "-gdb-set mi-async".
3825 Previously "-gdb-set target-async off" affected both MI execution
3826 commands and CLI execution commands.
3828 *** Changes in GDB 7.7
3830 * Improved support for process record-replay and reverse debugging on
3831 arm*-linux* targets. Support for thumb32 and syscall instruction
3832 recording has been added.
3834 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3836 * GDB now supports Fission DWP file format version 2.
3837 http://gcc.gnu.org/wiki/DebugFission
3839 * New convenience function "$_isvoid", to check whether an expression
3840 is void. A void expression is an expression where the type of the
3841 result is "void". For example, some convenience variables may be
3842 "void" when evaluated (e.g., "$_exitcode" before the execution of
3843 the program being debugged; or an undefined convenience variable).
3844 Another example, when calling a function whose return type is
3847 * The "maintenance print objfiles" command now takes an optional regexp.
3849 * The "catch syscall" command now works on arm*-linux* targets.
3851 * GDB now consistently shows "<not saved>" when printing values of
3852 registers the debug info indicates have not been saved in the frame
3853 and there's nowhere to retrieve them from
3854 (callee-saved/call-clobbered registers):
3859 (gdb) info registers rax
3862 Before, the former would print "<optimized out>", and the latter
3863 "*value not available*".
3865 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3870 ** Frame filters and frame decorators have been added.
3871 ** Temporary breakpoints are now supported.
3872 ** Line tables representation has been added.
3873 ** New attribute 'parent_type' for gdb.Field objects.
3874 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3875 ** New attribute 'name' for gdb.Type objects.
3879 Nios II ELF nios2*-*-elf
3880 Nios II GNU/Linux nios2*-*-linux
3881 Texas Instruments MSP430 msp430*-*-elf
3883 * Removed native configurations
3885 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3886 been removed. ELF variants of these configurations are kept supported.
3888 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3889 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3890 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3891 i[34567]86-*-openbsd3.[0-3]
3892 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3893 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3894 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3898 Like "catch throw", but catches a re-thrown exception.
3899 maint check-psymtabs
3900 Renamed from old "maint check-symtabs".
3902 Perform consistency checks on symtabs.
3903 maint expand-symtabs
3904 Expand symtabs matching an optional regexp.
3907 Display the details of GDB configure-time options.
3909 maint set|show per-command
3910 maint set|show per-command space
3911 maint set|show per-command time
3912 maint set|show per-command symtab
3913 Enable display of per-command gdb resource usage.
3915 remove-symbol-file FILENAME
3916 remove-symbol-file -a ADDRESS
3917 Remove a symbol file added via add-symbol-file. The file to remove
3918 can be identified by its filename or by an address that lies within
3919 the boundaries of this symbol file in memory.
3922 info exceptions REGEXP
3923 Display the list of Ada exceptions defined in the program being
3924 debugged. If provided, only the exceptions whose names match REGEXP
3929 set debug symfile off|on
3931 Control display of debugging info regarding reading symbol files and
3932 symbol tables within those files
3934 set print raw frame-arguments
3935 show print raw frame-arguments
3936 Set/show whether to print frame arguments in raw mode,
3937 disregarding any defined pretty-printers.
3939 set remote trace-status-packet
3940 show remote trace-status-packet
3941 Set/show the use of remote protocol qTStatus packet.
3945 Control display of debugging messages related to Nios II targets.
3949 Control whether target-assisted range stepping is enabled.
3951 set startup-with-shell
3952 show startup-with-shell
3953 Specifies whether Unix child processes are started via a shell or
3958 Use the target memory cache for accesses to the code segment. This
3959 improves performance of remote debugging (particularly disassembly).
3961 * You can now use a literal value 'unlimited' for options that
3962 interpret 0 or -1 as meaning "unlimited". E.g., "set
3963 trace-buffer-size unlimited" is now an alias for "set
3964 trace-buffer-size -1" and "set height unlimited" is now an alias for
3967 * The "set debug symtab-create" debugging option of GDB has been changed to
3968 accept a verbosity level. 0 means "off", 1 provides basic debugging
3969 output, and values of 2 or greater provides more verbose output.
3971 * New command-line options
3973 Display the details of GDB configure-time options.
3975 * The command 'tsave' can now support new option '-ctf' to save trace
3976 buffer in Common Trace Format.
3978 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3981 * GDB now implements the C++ 'typeid' operator.
3983 * The new convenience variable $_exception holds the exception being
3984 thrown or caught at an exception-related catchpoint.
3986 * The exception-related catchpoints, like "catch throw", now accept a
3987 regular expression which can be used to filter exceptions by type.
3989 * The new convenience variable $_exitsignal is automatically set to
3990 the terminating signal number when the program being debugged dies
3991 due to an uncaught signal.
3995 ** All MI commands now accept an optional "--language" option.
3996 Support for this feature can be verified by using the "-list-features"
3997 command, which should contain "language-option".
3999 ** The new command -info-gdb-mi-command allows the user to determine
4000 whether a GDB/MI command is supported or not.
4002 ** The "^error" result record returned when trying to execute an undefined
4003 GDB/MI command now provides a variable named "code" whose content is the
4004 "undefined-command" error code. Support for this feature can be verified
4005 by using the "-list-features" command, which should contain
4006 "undefined-command-error-code".
4008 ** The -trace-save MI command can optionally save trace buffer in Common
4011 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
4013 ** The command -data-list-register-values now accepts an optional
4014 "--skip-unavailable" option. When used, only the available registers
4017 ** The new command -trace-frame-collected dumps collected variables,
4018 computed expressions, tvars, memory and registers in a traceframe.
4020 ** The commands -stack-list-locals, -stack-list-arguments and
4021 -stack-list-variables now accept an option "--skip-unavailable".
4022 When used, only the available locals or arguments are displayed.
4024 ** The -exec-run command now accepts an optional "--start" option.
4025 When used, the command follows the same semantics as the "start"
4026 command, stopping the program's execution at the start of its
4027 main subprogram. Support for this feature can be verified using
4028 the "-list-features" command, which should contain
4029 "exec-run-start-option".
4031 ** The new commands -catch-assert and -catch-exceptions insert
4032 catchpoints stopping the program when Ada exceptions are raised.
4034 ** The new command -info-ada-exceptions provides the equivalent of
4035 the new "info exceptions" command.
4037 * New system-wide configuration scripts
4038 A GDB installation now provides scripts suitable for use as system-wide
4039 configuration scripts for the following systems:
4043 * GDB now supports target-assigned range stepping with remote targets.
4044 This improves the performance of stepping source lines by reducing
4045 the number of control packets from/to GDB. See "New remote packets"
4048 * GDB now understands the element 'tvar' in the XML traceframe info.
4049 It has the id of the collected trace state variables.
4051 * On S/390 targets that provide the transactional-execution feature,
4052 the program interruption transaction diagnostic block (TDB) is now
4053 represented as a number of additional "registers" in GDB.
4055 * New remote packets
4059 The vCont packet supports a new 'r' action, that tells the remote
4060 stub to step through an address range itself, without GDB
4061 involvemement at each single-step.
4063 qXfer:libraries-svr4:read's annex
4064 The previously unused annex of the qXfer:libraries-svr4:read packet
4065 is now used to support passing an argument list. The remote stub
4066 reports support for this argument list to GDB's qSupported query.
4067 The defined arguments are "start" and "prev", used to reduce work
4068 necessary for library list updating, resulting in significant
4071 * New features in the GDB remote stub, GDBserver
4073 ** GDBserver now supports target-assisted range stepping. Currently
4074 enabled on x86/x86_64 GNU/Linux targets.
4076 ** GDBserver now adds element 'tvar' in the XML in the reply to
4077 'qXfer:traceframe-info:read'. It has the id of the collected
4078 trace state variables.
4080 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
4083 * New 'z' formatter for printing and examining memory, this displays the
4084 value as hexadecimal zero padded on the left to the size of the type.
4086 * GDB can now use Windows x64 unwinding data.
4088 * The "set remotebaud" command has been replaced by "set serial baud".
4089 Similarly, "show remotebaud" has been replaced by "show serial baud".
4090 The "set remotebaud" and "show remotebaud" commands are still available
4091 to provide backward compatibility with older versions of GDB.
4093 *** Changes in GDB 7.6
4095 * Target record has been renamed to record-full.
4096 Record/replay is now enabled with the "record full" command.
4097 This also affects settings that are associated with full record/replay
4098 that have been moved from "set/show record" to "set/show record full":
4100 set|show record full insn-number-max
4101 set|show record full stop-at-limit
4102 set|show record full memory-query
4104 * A new record target "record-btrace" has been added. The new target
4105 uses hardware support to record the control-flow of a process. It
4106 does not support replaying the execution, but it implements the
4107 below new commands for investigating the recorded execution log.
4108 This new recording method can be enabled using:
4112 The "record-btrace" target is only available on Intel Atom processors
4113 and requires a Linux kernel 2.6.32 or later.
4115 * Two new commands have been added for record/replay to give information
4116 about the recorded execution without having to replay the execution.
4117 The commands are only supported by "record btrace".
4119 record instruction-history prints the execution history at
4120 instruction granularity
4122 record function-call-history prints the execution history at
4123 function granularity
4125 * New native configurations
4127 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
4128 FreeBSD/powerpc powerpc*-*-freebsd
4129 x86_64/Cygwin x86_64-*-cygwin*
4130 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
4134 ARM AArch64 aarch64*-*-elf
4135 ARM AArch64 GNU/Linux aarch64*-*-linux
4136 Lynx 178 PowerPC powerpc-*-lynx*178
4137 x86_64/Cygwin x86_64-*-cygwin*
4138 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
4140 * If the configured location of system.gdbinit file (as given by the
4141 --with-system-gdbinit option at configure time) is in the
4142 data-directory (as specified by --with-gdb-datadir at configure
4143 time) or in one of its subdirectories, then GDB will look for the
4144 system-wide init file in the directory specified by the
4145 --data-directory command-line option.
4147 * New command line options:
4149 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
4150 other initialization files, unlike -nx which disables all of them.
4152 * Removed command line options
4154 -epoch This was used by the gdb mode in Epoch, an ancient fork of
4157 * The 'ptype' and 'whatis' commands now accept an argument to control
4160 * 'info proc' now works on some core files.
4164 ** Vectors can be created with gdb.Type.vector.
4166 ** Python's atexit.register now works in GDB.
4168 ** Types can be pretty-printed via a Python API.
4170 ** Python 3 is now supported (in addition to Python 2.4 or later)
4172 ** New class gdb.Architecture exposes GDB's internal representation
4173 of architecture in the Python API.
4175 ** New method Frame.architecture returns the gdb.Architecture object
4176 corresponding to the frame's architecture.
4178 * New Python-based convenience functions:
4180 ** $_memeq(buf1, buf2, length)
4181 ** $_streq(str1, str2)
4183 ** $_regex(str, regex)
4185 * The 'cd' command now defaults to using '~' (the home directory) if not
4188 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
4189 default for GCC since November 2000.
4191 * The command 'forward-search' can now be abbreviated as 'fo'.
4193 * The command 'info tracepoints' can now display 'installed on target'
4194 or 'not installed on target' for each non-pending location of tracepoint.
4196 * New configure options
4198 --enable-libmcheck/--disable-libmcheck
4199 By default, development versions are built with -lmcheck on hosts
4200 that support it, in order to help track memory corruption issues.
4201 Release versions, on the other hand, are built without -lmcheck
4202 by default. The --enable-libmcheck/--disable-libmcheck configure
4203 options allow the user to override that default.
4204 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
4205 This configure option allows the user to build GDB with
4206 libbabeltrace using which GDB can read Common Trace Format data.
4208 * New commands (for set/show, see "New options" below)
4211 Catch signals. This is similar to "handle", but allows commands and
4212 conditions to be attached.
4215 List the BFDs known to GDB.
4217 python-interactive [command]
4219 Start a Python interactive prompt, or evaluate the optional command
4220 and print the result of expressions.
4223 "py" is a new alias for "python".
4225 enable type-printer [name]...
4226 disable type-printer [name]...
4227 Enable or disable type printers.
4231 ** For the Renesas Super-H architecture, the "regs" command has been removed
4232 (has been deprecated in GDB 7.5), and "info all-registers" should be used
4237 set print type methods (on|off)
4238 show print type methods
4239 Control whether method declarations are displayed by "ptype".
4240 The default is to show them.
4242 set print type typedefs (on|off)
4243 show print type typedefs
4244 Control whether typedef definitions are displayed by "ptype".
4245 The default is to show them.
4247 set filename-display basename|relative|absolute
4248 show filename-display
4249 Control the way in which filenames is displayed.
4250 The default is "relative", which preserves previous behavior.
4252 set trace-buffer-size
4253 show trace-buffer-size
4254 Request target to change the size of trace buffer.
4256 set remote trace-buffer-size-packet auto|on|off
4257 show remote trace-buffer-size-packet
4258 Control the use of the remote protocol `QTBuffer:size' packet.
4262 Control display of debugging messages related to ARM AArch64.
4265 set debug coff-pe-read
4266 show debug coff-pe-read
4267 Control display of debugging messages related to reading of COFF/PE
4272 Control display of debugging messages related to Mach-O symbols
4275 set debug notification
4276 show debug notification
4277 Control display of debugging info for async remote notification.
4281 ** Command parameter changes are now notified using new async record
4282 "=cmd-param-changed".
4283 ** Trace frame changes caused by command "tfind" are now notified using
4284 new async record "=traceframe-changed".
4285 ** The creation, deletion and modification of trace state variables
4286 are now notified using new async records "=tsv-created",
4287 "=tsv-deleted" and "=tsv-modified".
4288 ** The start and stop of process record are now notified using new
4289 async record "=record-started" and "=record-stopped".
4290 ** Memory changes are now notified using new async record
4292 ** The data-disassemble command response will include a "fullname" field
4293 containing the absolute file name when source has been requested.
4294 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
4295 command, to allow pattern filling of memory areas.
4296 ** New commands "-catch-load"/"-catch-unload" added for intercepting
4297 library load/unload events.
4298 ** The response to breakpoint commands and breakpoint async records
4299 includes an "installed" field containing a boolean state about each
4300 non-pending tracepoint location is whether installed on target or not.
4301 ** Output of the "-trace-status" command includes a "trace-file" field
4302 containing the name of the trace file being examined. This field is
4303 optional, and only present when examining a trace file.
4304 ** The "fullname" field is now always present along with the "file" field,
4305 even if the file cannot be found by GDB.
4307 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4308 You must have the LZMA library available when configuring GDB for this
4309 feature to be enabled. For more information, see:
4310 http://fedoraproject.org/wiki/Features/MiniDebugInfo
4312 * New remote packets
4315 Set the size of trace buffer. The remote stub reports support for this
4316 packet to gdb's qSupported query.
4319 Enable Branch Trace Store (BTS)-based branch tracing for the current
4320 thread. The remote stub reports support for this packet to gdb's
4324 Disable branch tracing for the current thread. The remote stub reports
4325 support for this packet to gdb's qSupported query.
4328 Read the traced branches for the current thread. The remote stub
4329 reports support for this packet to gdb's qSupported query.
4331 *** Changes in GDB 7.5
4333 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
4334 for more x32 ABI info.
4336 * GDB now supports access to MIPS DSP registers on Linux targets.
4338 * GDB now supports debugging microMIPS binaries.
4340 * The "info os" command on GNU/Linux can now display information on
4341 several new classes of objects managed by the operating system:
4342 "info os procgroups" lists process groups
4343 "info os files" lists file descriptors
4344 "info os sockets" lists internet-domain sockets
4345 "info os shm" lists shared-memory regions
4346 "info os semaphores" lists semaphores
4347 "info os msg" lists message queues
4348 "info os modules" lists loaded kernel modules
4350 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
4351 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
4352 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4353 options and inspect the probe arguments using the new $_probe_arg family
4354 of convenience variables. You can obtain more information about SystemTap
4355 in <http://sourceware.org/systemtap/>.
4357 * GDB now supports reversible debugging on ARM, it allows you to
4358 debug basic ARM and THUMB instructions, and provides
4359 record/replay support.
4361 * The option "symbol-reloading" has been deleted as it is no longer used.
4365 ** GDB commands implemented in Python can now be put in command class
4368 ** The "maint set python print-stack on|off" is now deleted.
4370 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4371 apply "flag enum"-style pretty-printing to any enum.
4373 ** gdb.lookup_symbol can now work when there is no current frame.
4375 ** gdb.Symbol now has a 'line' attribute, holding the line number in
4376 the source at which the symbol was defined.
4378 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4379 method 'value'. The former indicates whether the symbol needs a
4380 frame in order to compute its value, and the latter computes the
4383 ** A new method 'referenced_value' on gdb.Value objects which can
4384 dereference pointer as well as C++ reference values.
4386 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4387 which return the global and static blocks (as gdb.Block objects),
4388 of the underlying symbol table, respectively.
4390 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4391 object associated with a PC value.
4393 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4394 of the address range occupied by code for the current source line.
4396 * Go language support.
4397 GDB now supports debugging programs written in the Go programming
4400 * GDBserver now supports stdio connections.
4401 E.g. (gdb) target remote | ssh myhost gdbserver - hello
4403 * The binary "gdbtui" can no longer be built or installed.
4404 Use "gdb -tui" instead.
4406 * GDB will now print "flag" enums specially. A flag enum is one where
4407 all the enumerator values have no bits in common when pairwise
4408 "and"ed. When printing a value whose type is a flag enum, GDB will
4409 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4410 (gdb) print (enum E) 3
4413 * The filename part of a linespec will now match trailing components
4414 of a source file name. For example, "break gcc/expr.c:1000" will
4415 now set a breakpoint in build/gcc/expr.c, but not
4416 build/libcpp/expr.c.
4418 * The "info proc" and "generate-core-file" commands will now also
4419 work on remote targets connected to GDBserver on Linux.
4421 * The command "info catch" has been removed. It has been disabled
4422 since December 2007.
4424 * The "catch exception" and "catch assert" commands now accept
4425 a condition at the end of the command, much like the "break"
4426 command does. For instance:
4428 (gdb) catch exception Constraint_Error if Barrier = True
4430 Previously, it was possible to add a condition to such catchpoints,
4431 but it had to be done as a second step, after the catchpoint had been
4432 created, using the "condition" command.
4434 * The "info static-tracepoint-marker" command will now also work on
4435 native Linux targets with in-process agent.
4437 * GDB can now set breakpoints on inlined functions.
4439 * The .gdb_index section has been updated to include symbols for
4440 inlined functions. GDB will ignore older .gdb_index sections by
4441 default, which could cause symbol files to be loaded more slowly
4442 until their .gdb_index sections can be recreated. The new command
4443 "set use-deprecated-index-sections on" will cause GDB to use any older
4444 .gdb_index sections it finds. This will restore performance, but the
4445 ability to set breakpoints on inlined functions will be lost in symbol
4446 files with older .gdb_index sections.
4448 The .gdb_index section has also been updated to record more information
4449 about each symbol. This speeds up the "info variables", "info functions"
4450 and "info types" commands when used with programs having the .gdb_index
4451 section, as well as speeding up debugging with shared libraries using
4452 the .gdb_index section.
4454 * Ada support for GDB/MI Variable Objects has been added.
4456 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4461 ** New command -info-os is the MI equivalent of "info os".
4463 ** Output logs ("set logging" and related) now include MI output.
4467 ** "set use-deprecated-index-sections on|off"
4468 "show use-deprecated-index-sections on|off"
4469 Controls the use of deprecated .gdb_index sections.
4471 ** "catch load" and "catch unload" can be used to stop when a shared
4472 library is loaded or unloaded, respectively.
4474 ** "enable count" can be used to auto-disable a breakpoint after
4477 ** "info vtbl" can be used to show the virtual method tables for
4478 C++ and Java objects.
4480 ** "explore" and its sub commands "explore value" and "explore type"
4481 can be used to recursively explore values and types of
4482 expressions. These commands are available only if GDB is
4483 configured with '--with-python'.
4485 ** "info auto-load" shows status of all kinds of auto-loaded files,
4486 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4487 sequences of commands files, "info auto-load python-scripts"
4488 shows status of auto-loading Python script files,
4489 "info auto-load local-gdbinit" shows status of loading init file
4490 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4491 status of inferior specific thread debugging shared library loading.
4493 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4494 and "show auto-load-scripts" commands have been deprecated, use their
4495 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4496 and "show auto-load python-scripts" counterparts instead.
4498 ** "dprintf location,format,args..." creates a dynamic printf, which
4499 is basically a breakpoint that does a printf and immediately
4500 resumes your program's execution, so it is like a printf that you
4501 can insert dynamically at runtime instead of at compiletime.
4503 ** "set print symbol"
4505 Controls whether GDB attempts to display the symbol, if any,
4506 corresponding to addresses it prints. This defaults to "on", but
4507 you can set it to "off" to restore GDB's previous behavior.
4509 * Deprecated commands
4511 ** For the Renesas Super-H architecture, the "regs" command has been
4512 deprecated, and "info all-registers" should be used instead.
4516 Renesas RL78 rl78-*-elf
4517 HP OpenVMS ia64 ia64-hp-openvms*
4519 * GDBserver supports evaluation of breakpoint conditions. When
4520 support is advertised by GDBserver, GDB may be told to send the
4521 breakpoint conditions in bytecode form to GDBserver. GDBserver
4522 will only report the breakpoint trigger to GDB when its condition
4527 set mips compression
4528 show mips compression
4529 Select the compressed ISA encoding used in functions that have no symbol
4530 information available. The encoding can be set to either of:
4533 and is updated automatically from ELF file flags if available.
4535 set breakpoint condition-evaluation
4536 show breakpoint condition-evaluation
4537 Control whether breakpoint conditions are evaluated by GDB ("host") or by
4538 GDBserver ("target"). Default option "auto" chooses the most efficient
4540 This option can improve debugger efficiency depending on the speed of the
4544 Disable auto-loading globally.
4547 Show auto-loading setting of all kinds of auto-loaded files.
4549 set auto-load gdb-scripts on|off
4550 show auto-load gdb-scripts
4551 Control auto-loading of GDB canned sequences of commands files.
4553 set auto-load python-scripts on|off
4554 show auto-load python-scripts
4555 Control auto-loading of Python script files.
4557 set auto-load local-gdbinit on|off
4558 show auto-load local-gdbinit
4559 Control loading of init file (.gdbinit) from current directory.
4561 set auto-load libthread-db on|off
4562 show auto-load libthread-db
4563 Control auto-loading of inferior specific thread debugging shared library.
4565 set auto-load scripts-directory <dir1>[:<dir2>...]
4566 show auto-load scripts-directory
4567 Set a list of directories from which to load auto-loaded scripts.
4568 Automatically loaded Python scripts and GDB scripts are located in one
4569 of the directories listed by this option.
4570 The delimiter (':' above) may differ according to the host platform.
4572 set auto-load safe-path <dir1>[:<dir2>...]
4573 show auto-load safe-path
4574 Set a list of directories from which it is safe to auto-load files.
4575 The delimiter (':' above) may differ according to the host platform.
4577 set debug auto-load on|off
4578 show debug auto-load
4579 Control display of debugging info for auto-loading the files above.
4581 set dprintf-style gdb|call|agent
4583 Control the way in which a dynamic printf is performed; "gdb"
4584 requests a GDB printf command, while "call" causes dprintf to call a
4585 function in the inferior. "agent" requests that the target agent
4586 (such as GDBserver) do the printing.
4588 set dprintf-function <expr>
4589 show dprintf-function
4590 set dprintf-channel <expr>
4591 show dprintf-channel
4592 Set the function and optional first argument to the call when using
4593 the "call" style of dynamic printf.
4595 set disconnected-dprintf on|off
4596 show disconnected-dprintf
4597 Control whether agent-style dynamic printfs continue to be in effect
4598 after GDB disconnects.
4600 * New configure options
4602 --with-auto-load-dir
4603 Configure default value for the 'set auto-load scripts-directory'
4604 setting above. It defaults to '$debugdir:$datadir/auto-load',
4605 $debugdir representing global debugging info directories (available
4606 via 'show debug-file-directory') and $datadir representing GDB's data
4607 directory (available via 'show data-directory').
4609 --with-auto-load-safe-path
4610 Configure default value for the 'set auto-load safe-path' setting
4611 above. It defaults to the --with-auto-load-dir setting.
4613 --without-auto-load-safe-path
4614 Set 'set auto-load safe-path' to '/', effectively disabling this
4617 * New remote packets
4619 z0/z1 conditional breakpoints extension
4621 The z0/z1 breakpoint insertion packets have been extended to carry
4622 a list of conditional expressions over to the remote stub depending on the
4623 condition evaluation mode. The use of this extension can be controlled
4624 via the "set remote conditional-breakpoints-packet" command.
4628 Specify the signals which the remote stub may pass to the debugged
4629 program without GDB involvement.
4631 * New command line options
4633 --init-command=FILE, -ix Like --command, -x but execute it
4634 before loading inferior.
4635 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4636 execute it before loading inferior.
4638 *** Changes in GDB 7.4
4640 * GDB now handles ambiguous linespecs more consistently; the existing
4641 FILE:LINE support has been expanded to other types of linespecs. A
4642 breakpoint will now be set on all matching locations in all
4643 inferiors, and locations will be added or removed according to
4646 * GDB now allows you to skip uninteresting functions and files when
4647 stepping with the "skip function" and "skip file" commands.
4649 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4650 and "show remote hardware-watchpoint-length-limit". These allows to
4651 set or show the maximum length limit (in bytes) of a remote
4652 target hardware watchpoint.
4654 This allows e.g. to use "unlimited" hardware watchpoints with the
4655 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
4656 watchpoints are slower than real hardware watchpoints but are
4657 significantly faster than gdb software watchpoints.
4661 ** The register_pretty_printer function in module gdb.printing now takes
4662 an optional `replace' argument. If True, the new printer replaces any
4665 ** The "maint set python print-stack on|off" command has been
4666 deprecated and will be deleted in GDB 7.5.
4667 A new command: "set python print-stack none|full|message" has
4668 replaced it. Additionally, the default for "print-stack" is
4669 now "message", which just prints the error message without
4672 ** A prompt substitution hook (prompt_hook) is now available to the
4675 ** A new Python module, gdb.prompt has been added to the GDB Python
4676 modules library. This module provides functionality for
4677 escape sequences in prompts (used by set/show
4678 extended-prompt). These escape sequences are replaced by their
4679 corresponding value.
4681 ** Python commands and convenience-functions located in
4682 'data-directory'/python/gdb/command and
4683 'data-directory'/python/gdb/function are now automatically loaded
4686 ** Blocks now provide four new attributes. global_block and
4687 static_block will return the global and static blocks
4688 respectively. is_static and is_global are boolean attributes
4689 that indicate if the block is one of those two types.
4691 ** Symbols now provide the "type" attribute, the type of the symbol.
4693 ** The "gdb.breakpoint" function has been deprecated in favor of
4696 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4697 of a function. This class is based on the "finish" command
4698 available in the CLI.
4700 ** Type objects for struct and union types now allow access to
4701 the fields using standard Python dictionary (mapping) methods.
4702 For example, "some_type['myfield']" now works, as does
4703 "some_type.items()".
4705 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4708 ** A new function, "deep_items" has been added to the gdb.types
4709 module in the GDB Python modules library. This function returns
4710 an iterator over the fields of a struct or union type. Unlike
4711 the standard Python "iteritems" method, it will recursively traverse
4712 any anonymous fields.
4716 ** "*stopped" events can report several new "reason"s, such as
4719 ** Breakpoint changes are now notified using new async records, like
4720 "=breakpoint-modified".
4722 ** New command -ada-task-info.
4724 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4725 $sdir specifies the default system locations of shared libraries.
4726 $pdir specifies the directory where the libpthread used by the application
4729 GDB no longer looks in $sdir and $pdir after it has searched the directories
4730 mentioned in libthread-db-search-path. If you want to search those
4731 directories, they must be specified in libthread-db-search-path.
4732 The default value of libthread-db-search-path on GNU/Linux and Solaris
4733 systems is now "$sdir:$pdir".
4735 $pdir is not supported by gdbserver, it is currently ignored.
4736 $sdir is supported by gdbserver.
4738 * New configure option --with-iconv-bin.
4739 When using the internationalization support like the one in the GNU C
4740 library, GDB will invoke the "iconv" program to get a list of supported
4741 character sets. If this program lives in a non-standard location, one can
4742 use this option to specify where to find it.
4744 * When natively debugging programs on PowerPC BookE processors running
4745 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4746 watchpoints, which specify a mask in addition to an address to watch.
4747 The mask specifies that some bits of an address (the bits which are
4748 reset in the mask) should be ignored when matching the address accessed
4749 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4750 section in the user manual for more details.
4752 * The new option --once causes GDBserver to stop listening for connections once
4753 the first connection is made. The listening port used by GDBserver will
4754 become available after that.
4756 * New commands "info macros" and "alias" have been added.
4758 * New function parameters suffix @entry specifies value of function parameter
4759 at the time the function got called. Entry values are available only since
4765 "!" is now an alias of the "shell" command.
4766 Note that no space is needed between "!" and SHELL COMMAND.
4770 watch EXPRESSION mask MASK_VALUE
4771 The watch command now supports the mask argument which allows creation
4772 of masked watchpoints, if the current architecture supports this feature.
4774 info auto-load-scripts [REGEXP]
4775 This command was formerly named "maintenance print section-scripts".
4776 It is now generally useful and is no longer a maintenance-only command.
4778 info macro [-all] [--] MACRO
4779 The info macro command has new options `-all' and `--'. The first for
4780 printing all definitions of a macro. The second for explicitly specifying
4781 the end of arguments and the beginning of the macro name in case the macro
4782 name starts with a hyphen.
4784 collect[/s] EXPRESSIONS
4785 The tracepoint collect command now takes an optional modifier "/s"
4786 that directs it to dereference pointer-to-character types and
4787 collect the bytes of memory up to a zero byte. The behavior is
4788 similar to what you see when you use the regular print command on a
4789 string. An optional integer following the "/s" sets a bound on the
4790 number of bytes that will be collected.
4793 The trace start command now interprets any supplied arguments as a
4794 note to be recorded with the trace run, with an effect similar to
4795 setting the variable trace-notes.
4798 The trace stop command now interprets any arguments as a note to be
4799 mentioned along with the tstatus report that the trace was stopped
4800 with a command. The effect is similar to setting the variable
4803 * Tracepoints can now be enabled and disabled at any time after a trace
4804 experiment has been started using the standard "enable" and "disable"
4805 commands. It is now possible to start a trace experiment with no enabled
4806 tracepoints; GDB will display a warning, but will allow the experiment to
4807 begin, assuming that tracepoints will be enabled as needed while the trace
4810 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4811 locations with 4-byte instructions, when they were previously
4812 limited to locations with instructions of 5 bytes or longer.
4816 set debug dwarf2-read
4817 show debug dwarf2-read
4818 Turns on or off display of debugging messages related to reading
4819 DWARF debug info. The default is off.
4821 set debug symtab-create
4822 show debug symtab-create
4823 Turns on or off display of debugging messages related to symbol table
4824 creation. The default is off.
4827 show extended-prompt
4828 Set the GDB prompt, and allow escape sequences to be inserted to
4829 display miscellaneous information (see 'help set extended-prompt'
4830 for the list of sequences). This prompt (and any information
4831 accessed through the escape sequences) is updated every time the
4832 prompt is displayed.
4834 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4835 show print entry-values
4836 Set printing of frame argument values at function entry. In some cases
4837 GDB can determine the value of function argument which was passed by the
4838 function caller, even if the value was modified inside the called function.
4840 set debug entry-values
4841 show debug entry-values
4842 Control display of debugging info for determining frame argument values at
4843 function entry and virtual tail call frames.
4845 set basenames-may-differ
4846 show basenames-may-differ
4847 Set whether a source file may have multiple base names.
4848 (A "base name" is the name of a file with the directory part removed.
4849 Example: The base name of "/home/user/hello.c" is "hello.c".)
4850 If set, GDB will canonicalize file names (e.g., expand symlinks)
4851 before comparing them. Canonicalization is an expensive operation,
4852 but it allows the same file be known by more than one base name.
4853 If not set (the default), all source files are assumed to have just
4854 one base name, and gdb will do file name comparisons more efficiently.
4860 Set a user name and notes for the current and any future trace runs.
4861 This is useful for long-running and/or disconnected traces, to
4862 inform others (or yourself) as to who is running the trace, supply
4863 contact information, or otherwise explain what is going on.
4865 set trace-stop-notes
4866 show trace-stop-notes
4867 Set a note attached to the trace run, that is displayed when the
4868 trace has been stopped by a tstop command. This is useful for
4869 instance as an explanation, if you are stopping a trace run that was
4870 started by someone else.
4872 * New remote packets
4876 Dynamically enable a tracepoint in a started trace experiment.
4880 Dynamically disable a tracepoint in a started trace experiment.
4884 Set the user and notes of the trace run.
4888 Query the current status of a tracepoint.
4892 Query the minimum length of instruction at which a fast tracepoint may
4895 * Dcache size (number of lines) and line-size are now runtime-configurable
4896 via "set dcache line" and "set dcache line-size" commands.
4900 Texas Instruments TMS320C6x tic6x-*-*
4904 Renesas RL78 rl78-*-elf
4906 *** Changes in GDB 7.3.1
4908 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4910 *** Changes in GDB 7.3
4912 * GDB has a new command: "thread find [REGEXP]".
4913 It finds the thread id whose name, target id, or thread extra info
4914 matches the given regular expression.
4916 * The "catch syscall" command now works on mips*-linux* targets.
4918 * The -data-disassemble MI command now supports modes 2 and 3 for
4919 dumping the instruction opcodes.
4921 * New command line options
4923 -data-directory DIR Specify DIR as the "data-directory".
4924 This is mostly for testing purposes.
4926 * The "maint set python auto-load on|off" command has been renamed to
4927 "set auto-load-scripts on|off".
4929 * GDB has a new command: "set directories".
4930 It is like the "dir" command except that it replaces the
4931 source path list instead of augmenting it.
4933 * GDB now understands thread names.
4935 On GNU/Linux, "info threads" will display the thread name as set by
4936 prctl or pthread_setname_np.
4938 There is also a new command, "thread name", which can be used to
4939 assign a name internally for GDB to display.
4942 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4943 has been integrated into GDB.
4947 ** The function gdb.Write now accepts an optional keyword 'stream'.
4948 This keyword, when provided, will direct the output to either
4949 stdout, stderr, or GDB's logging output.
4951 ** Parameters can now be be sub-classed in Python, and in particular
4952 you may implement the get_set_doc and get_show_doc functions.
4953 This improves how Parameter set/show documentation is processed
4954 and allows for more dynamic content.
4956 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4957 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4958 have an is_valid method.
4960 ** Breakpoints can now be sub-classed in Python, and in particular
4961 you may implement a 'stop' function that is executed each time
4962 the inferior reaches that breakpoint.
4964 ** New function gdb.lookup_global_symbol looks up a global symbol.
4966 ** GDB values in Python are now callable if the value represents a
4967 function. For example, if 'some_value' represents a function that
4968 takes two integer parameters and returns a value, you can call
4969 that function like so:
4971 result = some_value (10,20)
4973 ** Module gdb.types has been added.
4974 It contains a collection of utilities for working with gdb.Types objects:
4975 get_basic_type, has_field, make_enum_dict.
4977 ** Module gdb.printing has been added.
4978 It contains utilities for writing and registering pretty-printers.
4979 New classes: PrettyPrinter, SubPrettyPrinter,
4980 RegexpCollectionPrettyPrinter.
4981 New function: register_pretty_printer.
4983 ** New commands "info pretty-printers", "enable pretty-printer" and
4984 "disable pretty-printer" have been added.
4986 ** gdb.parameter("directories") is now available.
4988 ** New function gdb.newest_frame returns the newest frame in the
4991 ** The gdb.InferiorThread class has a new "name" attribute. This
4992 holds the thread's name.
4994 ** Python Support for Inferior events.
4995 Python scripts can add observers to be notified of events
4996 occurring in the process being debugged.
4997 The following events are currently supported:
4998 - gdb.events.cont Continue event.
4999 - gdb.events.exited Inferior exited event.
5000 - gdb.events.stop Signal received, and Breakpoint hit events.
5004 ** GDB now puts template parameters in scope when debugging in an
5005 instantiation. For example, if you have:
5007 template<int X> int func (void) { return X; }
5009 then if you step into func<5>, "print X" will show "5". This
5010 feature requires proper debuginfo support from the compiler; it
5011 was added to GCC 4.5.
5013 ** The motion commands "next", "finish", "until", and "advance" now
5014 work better when exceptions are thrown. In particular, GDB will
5015 no longer lose control of the inferior; instead, the GDB will
5016 stop the inferior at the point at which the exception is caught.
5017 This functionality requires a change in the exception handling
5018 code that was introduced in GCC 4.5.
5020 * GDB now follows GCC's rules on accessing volatile objects when
5021 reading or writing target state during expression evaluation.
5022 One notable difference to prior behavior is that "print x = 0"
5023 no longer generates a read of x; the value of the assignment is
5024 now always taken directly from the value being assigned.
5026 * GDB now has some support for using labels in the program's source in
5027 linespecs. For instance, you can use "advance label" to continue
5028 execution to a label.
5030 * GDB now has support for reading and writing a new .gdb_index
5031 section. This section holds a fast index of DWARF debugging
5032 information and can be used to greatly speed up GDB startup and
5033 operation. See the documentation for `save gdb-index' for details.
5035 * The "watch" command now accepts an optional "-location" argument.
5036 When used, this causes GDB to watch the memory referred to by the
5037 expression. Such a watchpoint is never deleted due to it going out
5040 * GDB now supports thread debugging of core dumps on GNU/Linux.
5042 GDB now activates thread debugging using the libthread_db library
5043 when debugging GNU/Linux core dumps, similarly to when debugging
5044 live processes. As a result, when debugging a core dump file, GDB
5045 is now able to display pthread_t ids of threads. For example, "info
5046 threads" shows the same output as when debugging the process when it
5047 was live. In earlier releases, you'd see something like this:
5050 * 1 LWP 6780 main () at main.c:10
5052 While now you see this:
5055 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
5057 It is also now possible to inspect TLS variables when debugging core
5060 When debugging a core dump generated on a machine other than the one
5061 used to run GDB, you may need to point GDB at the correct
5062 libthread_db library with the "set libthread-db-search-path"
5063 command. See the user manual for more details on this command.
5065 * When natively debugging programs on PowerPC BookE processors running
5066 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
5067 which stop execution of the inferior whenever it executes an instruction
5068 at any address within the specified range. See the "PowerPC Embedded"
5069 section in the user manual for more details.
5071 * New features in the GDB remote stub, GDBserver
5073 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
5074 and i686 LynxOS (version 5.x).
5076 ** GDBserver is now supported on Blackfin Linux.
5078 * New native configurations
5080 ia64 HP-UX ia64-*-hpux*
5084 Analog Devices, Inc. Blackfin Processor bfin-*
5086 * Ada task switching is now supported on sparc-elf targets when
5087 debugging a program using the Ravenscar Profile. For more information,
5088 see the "Tasking Support when using the Ravenscar Profile" section
5089 in the GDB user manual.
5091 * Guile support was removed.
5093 * New features in the GNU simulator
5095 ** The --map-info flag lists all known core mappings.
5097 ** CFI flashes may be simulated via the "cfi" device.
5099 *** Changes in GDB 7.2
5101 * Shared library support for remote targets by default
5103 When GDB is configured for a generic, non-OS specific target, like
5104 for example, --target=arm-eabi or one of the many *-*-elf targets,
5105 GDB now queries remote stubs for loaded shared libraries using the
5106 `qXfer:libraries:read' packet. Previously, shared library support
5107 was always disabled for such configurations.
5111 ** Argument Dependent Lookup (ADL)
5113 In C++ ADL lookup directs function search to the namespaces of its
5114 arguments even if the namespace has not been imported.
5124 Here the compiler will search for `foo' in the namespace of 'b'
5125 and find A::foo. GDB now supports this. This construct is commonly
5126 used in the Standard Template Library for operators.
5128 ** Improved User Defined Operator Support
5130 In addition to member operators, GDB now supports lookup of operators
5131 defined in a namespace and imported with a `using' directive, operators
5132 defined in the global scope, operators imported implicitly from an
5133 anonymous namespace, and the ADL operators mentioned in the previous
5135 GDB now also supports proper overload resolution for all the previously
5136 mentioned flavors of operators.
5138 ** static const class members
5140 Printing of static const class members that are initialized in the
5141 class definition has been fixed.
5143 * Windows Thread Information Block access.
5145 On Windows targets, GDB now supports displaying the Windows Thread
5146 Information Block (TIB) structure. This structure is visible either
5147 by using the new command `info w32 thread-information-block' or, by
5148 dereferencing the new convenience variable named `$_tlb', a
5149 thread-specific pointer to the TIB. This feature is also supported
5150 when remote debugging using GDBserver.
5152 * Static tracepoints
5154 Static tracepoints are calls in the user program into a tracing
5155 library. One such library is a port of the LTTng kernel tracer to
5156 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
5157 When debugging with GDBserver, GDB now supports combining the GDB
5158 tracepoint machinery with such libraries. For example: the user can
5159 use GDB to probe a static tracepoint marker (a call from the user
5160 program into the tracing library) with the new "strace" command (see
5161 "New commands" below). This creates a "static tracepoint" in the
5162 breakpoint list, that can be manipulated with the same feature set
5163 as fast and regular tracepoints. E.g., collect registers, local and
5164 global variables, collect trace state variables, and define
5165 tracepoint conditions. In addition, the user can collect extra
5166 static tracepoint marker specific data, by collecting the new
5167 $_sdata internal variable. When analyzing the trace buffer, you can
5168 inspect $_sdata like any other variable available to GDB. For more
5169 information, see the "Tracepoints" chapter in GDB user manual. New
5170 remote packets have been defined to support static tracepoints, see
5171 the "New remote packets" section below.
5173 * Better reconstruction of tracepoints after disconnected tracing
5175 GDB will attempt to download the original source form of tracepoint
5176 definitions when starting a trace run, and then will upload these
5177 upon reconnection to the target, resulting in a more accurate
5178 reconstruction of the tracepoints that are in use on the target.
5182 You can now exercise direct control over the ways that GDB can
5183 affect your program. For instance, you can disallow the setting of
5184 breakpoints, so that the program can run continuously (assuming
5185 non-stop mode). In addition, the "observer" variable is available
5186 to switch all of the different controls; in observer mode, GDB
5187 cannot affect the target's behavior at all, which is useful for
5188 tasks like diagnosing live systems in the field.
5190 * The new convenience variable $_thread holds the number of the
5193 * New remote packets
5197 Return the address of the Windows Thread Information Block of a given thread.
5201 In response to several of the tracepoint packets, the target may now
5202 also respond with a number of intermediate `qRelocInsn' request
5203 packets before the final result packet, to have GDB handle
5204 relocating an instruction to execute at a different address. This
5205 is particularly useful for stubs that support fast tracepoints. GDB
5206 reports support for this feature in the qSupported packet.
5210 List static tracepoint markers in the target program.
5214 List static tracepoint markers at a given address in the target
5217 qXfer:statictrace:read
5219 Read the static trace data collected (by a `collect $_sdata'
5220 tracepoint action). The remote stub reports support for this packet
5221 to gdb's qSupported query.
5225 Send the current settings of GDB's permission flags.
5229 Send part of the source (textual) form of a tracepoint definition,
5230 which includes location, conditional, and action list.
5232 * The source command now accepts a -s option to force searching for the
5233 script in the source search path even if the script name specifies
5236 * New features in the GDB remote stub, GDBserver
5238 - GDBserver now support tracepoints (including fast tracepoints, and
5239 static tracepoints). The feature is currently supported by the
5240 i386-linux and amd64-linux builds. See the "Tracepoints support
5241 in gdbserver" section in the manual for more information.
5243 GDBserver JIT compiles the tracepoint's conditional agent
5244 expression bytecode into native code whenever possible for low
5245 overhead dynamic tracepoints conditionals. For such tracepoints,
5246 an expression that examines program state is evaluated when the
5247 tracepoint is reached, in order to determine whether to capture
5248 trace data. If the condition is simple and false, processing the
5249 tracepoint finishes very quickly and no data is gathered.
5251 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
5252 for static tracepoints support.
5254 - GDBserver now supports x86_64 Windows 64-bit debugging.
5256 * GDB now sends xmlRegisters= in qSupported packet to indicate that
5257 it understands register description.
5259 * The --batch flag now disables pagination and queries.
5261 * X86 general purpose registers
5263 GDB now supports reading/writing byte, word and double-word x86
5264 general purpose registers directly. This means you can use, say,
5265 $ah or $ax to refer, respectively, to the byte register AH and
5266 16-bit word register AX that are actually portions of the 32-bit
5267 register EAX or 64-bit register RAX.
5269 * The `commands' command now accepts a range of breakpoints to modify.
5270 A plain `commands' following a command that creates multiple
5271 breakpoints affects all the breakpoints set by that command. This
5272 applies to breakpoints set by `rbreak', and also applies when a
5273 single `break' command creates multiple breakpoints (e.g.,
5274 breakpoints on overloaded c++ functions).
5276 * The `rbreak' command now accepts a filename specification as part of
5277 its argument, limiting the functions selected by the regex to those
5278 in the specified file.
5280 * Support for remote debugging Windows and SymbianOS shared libraries
5281 from Unix hosts has been improved. Non Windows GDB builds now can
5282 understand target reported file names that follow MS-DOS based file
5283 system semantics, such as file names that include drive letters and
5284 use the backslash character as directory separator. This makes it
5285 possible to transparently use the "set sysroot" and "set
5286 solib-search-path" on Unix hosts to point as host copies of the
5287 target's shared libraries. See the new command "set
5288 target-file-system-kind" described below, and the "Commands to
5289 specify files" section in the user manual for more information.
5293 eval template, expressions...
5294 Convert the values of one or more expressions under the control
5295 of the string template to a command line, and call it.
5297 set target-file-system-kind unix|dos-based|auto
5298 show target-file-system-kind
5299 Set or show the assumed file system kind for target reported file
5302 save breakpoints <filename>
5303 Save all current breakpoint definitions to a file suitable for use
5304 in a later debugging session. To read the saved breakpoint
5305 definitions, use the `source' command.
5307 `save tracepoints' is a new alias for `save-tracepoints'. The latter
5310 info static-tracepoint-markers
5311 Display information about static tracepoint markers in the target.
5313 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5314 Define a static tracepoint by probing a marker at the given
5315 function, line, address, or marker ID.
5319 Enable and disable observer mode.
5321 set may-write-registers on|off
5322 set may-write-memory on|off
5323 set may-insert-breakpoints on|off
5324 set may-insert-tracepoints on|off
5325 set may-insert-fast-tracepoints on|off
5326 set may-interrupt on|off
5327 Set individual permissions for GDB effects on the target. Note that
5328 some of these settings can have undesirable or surprising
5329 consequences, particularly when changed in the middle of a session.
5330 For instance, disabling the writing of memory can prevent
5331 breakpoints from being inserted, cause single-stepping to fail, or
5332 even crash your program, if you disable after breakpoints have been
5333 inserted. However, GDB should not crash.
5335 set record memory-query on|off
5336 show record memory-query
5337 Control whether to stop the inferior if memory changes caused
5338 by an instruction cannot be recorded.
5343 The disassemble command now supports "start,+length" form of two arguments.
5347 ** GDB now provides a new directory location, called the python directory,
5348 where Python scripts written for GDB can be installed. The location
5349 of that directory is <data-directory>/python, where <data-directory>
5350 is the GDB data directory. For more details, see section `Scripting
5351 GDB using Python' in the manual.
5353 ** The GDB Python API now has access to breakpoints, symbols, symbol
5354 tables, program spaces, inferiors, threads and frame's code blocks.
5355 Additionally, GDB Parameters can now be created from the API, and
5356 manipulated via set/show in the CLI.
5358 ** New functions gdb.target_charset, gdb.target_wide_charset,
5359 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5361 ** New exception gdb.GdbError.
5363 ** Pretty-printers are now also looked up in the current program space.
5365 ** Pretty-printers can now be individually enabled and disabled.
5367 ** GDB now looks for names of Python scripts to auto-load in a
5368 special section named `.debug_gdb_scripts', in addition to looking
5369 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5371 * Tracepoint actions were unified with breakpoint commands. In particular,
5372 there are no longer differences in "info break" output for breakpoints and
5373 tracepoints and the "commands" command can be used for both tracepoints and
5374 regular breakpoints.
5378 ARM Symbian arm*-*-symbianelf*
5380 * D language support.
5381 GDB now supports debugging programs written in the D programming
5384 * GDB now supports the extended ptrace interface for PowerPC which is
5385 available since Linux kernel version 2.6.34. This automatically enables
5386 any hardware breakpoints and additional hardware watchpoints available in
5387 the processor. The old ptrace interface exposes just one hardware
5388 watchpoint and no hardware breakpoints.
5390 * GDB is now able to use the Data Value Compare (DVC) register available on
5391 embedded PowerPC processors to implement in hardware simple watchpoint
5392 conditions of the form:
5394 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5396 This works in native GDB running on Linux kernels with the extended ptrace
5397 interface mentioned above.
5399 *** Changes in GDB 7.1
5403 ** Namespace Support
5405 GDB now supports importing of namespaces in C++. This enables the
5406 user to inspect variables from imported namespaces. Support for
5407 namepace aliasing has also been added. So, if a namespace is
5408 aliased in the current scope (e.g. namepace C=A; ) the user can
5409 print variables using the alias (e.g. (gdb) print C::x).
5413 All known bugs relating to the printing of virtual base class were
5414 fixed. It is now possible to call overloaded static methods using a
5419 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5420 and reinterpret_cast<> are now handled by the C++ expression parser.
5424 Xilinx MicroBlaze microblaze-*-*
5429 Xilinx MicroBlaze microblaze
5432 * Multi-program debugging.
5434 GDB now has support for multi-program (a.k.a. multi-executable or
5435 multi-exec) debugging. This allows for debugging multiple inferiors
5436 simultaneously each running a different program under the same GDB
5437 session. See "Debugging Multiple Inferiors and Programs" in the
5438 manual for more information. This implied some user visible changes
5439 in the multi-inferior support. For example, "info inferiors" now
5440 lists inferiors that are not running yet or that have exited
5441 already. See also "New commands" and "New options" below.
5443 * New tracing features
5445 GDB's tracepoint facility now includes several new features:
5447 ** Trace state variables
5449 GDB tracepoints now include support for trace state variables, which
5450 are variables managed by the target agent during a tracing
5451 experiment. They are useful for tracepoints that trigger each
5452 other, so for instance one tracepoint can count hits in a variable,
5453 and then a second tracepoint has a condition that is true when the
5454 count reaches a particular value. Trace state variables share the
5455 $-syntax of GDB convenience variables, and can appear in both
5456 tracepoint actions and condition expressions. Use the "tvariable"
5457 command to create, and "info tvariables" to view; see "Trace State
5458 Variables" in the manual for more detail.
5462 GDB now includes an option for defining fast tracepoints, which
5463 targets may implement more efficiently, such as by installing a jump
5464 into the target agent rather than a trap instruction. The resulting
5465 speedup can be by two orders of magnitude or more, although the
5466 tradeoff is that some program locations on some target architectures
5467 might not allow fast tracepoint installation, for instance if the
5468 instruction to be replaced is shorter than the jump. To request a
5469 fast tracepoint, use the "ftrace" command, with syntax identical to
5470 the regular trace command.
5472 ** Disconnected tracing
5474 It is now possible to detach GDB from the target while it is running
5475 a trace experiment, then reconnect later to see how the experiment
5476 is going. In addition, a new variable disconnected-tracing lets you
5477 tell the target agent whether to continue running a trace if the
5478 connection is lost unexpectedly.
5482 GDB now has the ability to save the trace buffer into a file, and
5483 then use that file as a target, similarly to you can do with
5484 corefiles. You can select trace frames, print data that was
5485 collected in them, and use tstatus to display the state of the
5486 tracing run at the moment that it was saved. To create a trace
5487 file, use "tsave <filename>", and to use it, do "target tfile
5490 ** Circular trace buffer
5492 You can ask the target agent to handle the trace buffer as a
5493 circular buffer, discarding the oldest trace frames to make room for
5494 newer ones, by setting circular-trace-buffer to on. This feature may
5495 not be available for all target agents.
5500 The disassemble command, when invoked with two arguments, now requires
5501 the arguments to be comma-separated.
5504 The info variables command now displays variable definitions. Files
5505 which only declare a variable are not shown.
5508 The source command is now capable of sourcing Python scripts.
5509 This feature is dependent on the debugger being build with Python
5512 Related to this enhancement is also the introduction of a new command
5513 "set script-extension" (see below).
5515 * New commands (for set/show, see "New options" below)
5517 record save [<FILENAME>]
5518 Save a file (in core file format) containing the process record
5519 execution log for replay debugging at a later time.
5521 record restore <FILENAME>
5522 Restore the process record execution log that was saved at an
5523 earlier time, for replay debugging.
5525 add-inferior [-copies <N>] [-exec <FILENAME>]
5528 clone-inferior [-copies <N>] [ID]
5529 Make a new inferior ready to execute the same program another
5530 inferior has loaded.
5535 maint info program-spaces
5536 List the program spaces loaded into GDB.
5538 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5539 show remote interrupt-sequence
5540 Allow the user to select one of ^C, a BREAK signal or BREAK-g
5541 as the sequence to the remote target in order to interrupt the execution.
5542 Ctrl-C is a default. Some system prefers BREAK which is high level of
5543 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
5544 Magic SysRq g. It is BREAK signal and character 'g'.
5546 set remote interrupt-on-connect [on | off]
5547 show remote interrupt-on-connect
5548 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5549 remote target when gdb connects to it. This is needed when you debug
5552 set remotebreak [on | off]
5554 Deprecated. Use "set/show remote interrupt-sequence" instead.
5556 tvariable $NAME [ = EXP ]
5557 Create or modify a trace state variable.
5560 List trace state variables and their values.
5562 delete tvariable $NAME ...
5563 Delete one or more trace state variables.
5566 Evaluate the given expressions without collecting anything into the
5567 trace buffer. (Valid in tracepoint actions only.)
5569 ftrace FN / FILE:LINE / *ADDR
5570 Define a fast tracepoint at the given function, line, or address.
5572 * New expression syntax
5574 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5575 GDB now parses 0b101010 identically with 42.
5579 set follow-exec-mode new|same
5580 show follow-exec-mode
5581 Control whether GDB reuses the same inferior across an exec call or
5582 creates a new one. This is useful to be able to restart the old
5583 executable after the inferior having done an exec call.
5585 set default-collect EXPR, ...
5586 show default-collect
5587 Define a list of expressions to be collected at each tracepoint.
5588 This is a useful way to ensure essential items are not overlooked,
5589 such as registers or a critical global variable.
5591 set disconnected-tracing
5592 show disconnected-tracing
5593 If set to 1, the target is instructed to continue tracing if it
5594 loses its connection to GDB. If 0, the target is to stop tracing
5597 set circular-trace-buffer
5598 show circular-trace-buffer
5599 If set to on, the target is instructed to use a circular trace buffer
5600 and discard the oldest trace frames instead of stopping the trace due
5601 to a full trace buffer. If set to off, the trace stops when the buffer
5602 fills up. Some targets may not support this.
5604 set script-extension off|soft|strict
5605 show script-extension
5606 If set to "off", the debugger does not perform any script language
5607 recognition, and all sourced files are assumed to be GDB scripts.
5608 If set to "soft" (the default), files are sourced according to
5609 filename extension, falling back to GDB scripts if the first
5611 If set to "strict", files are sourced according to filename extension.
5613 set ada trust-PAD-over-XVS on|off
5614 show ada trust-PAD-over-XVS
5615 If off, activate a workaround against a bug in the debugging information
5616 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5617 the GCC sources for more information about the GNAT encoding and
5618 PAD types in particular). It is always safe to set this option to
5619 off, but this introduces a slight performance penalty. The default
5622 * Python API Improvements
5624 ** GDB provides the new class gdb.LazyString. This is useful in
5625 some pretty-printing cases. The new method gdb.Value.lazy_string
5626 provides a simple way to create objects of this type.
5628 ** The fields returned by gdb.Type.fields now have an
5629 `is_base_class' attribute.
5631 ** The new method gdb.Type.range returns the range of an array type.
5633 ** The new method gdb.parse_and_eval can be used to parse and
5634 evaluate an expression.
5636 * New remote packets
5639 Define a trace state variable.
5642 Get the current value of a trace state variable.
5645 Set desired tracing behavior upon disconnection.
5648 Set the trace buffer to be linear or circular.
5651 Get data about the tracepoints currently in use.
5655 Process record now works correctly with hardware watchpoints.
5657 Multiple bug fixes have been made to the mips-irix port, making it
5658 much more reliable. In particular:
5659 - Debugging threaded applications is now possible again. Previously,
5660 GDB would hang while starting the program, or while waiting for
5661 the program to stop at a breakpoint.
5662 - Attaching to a running process no longer hangs.
5663 - An error occurring while loading a core file has been fixed.
5664 - Changing the value of the PC register now works again. This fixes
5665 problems observed when using the "jump" command, or when calling
5666 a function from GDB, or even when assigning a new value to $pc.
5667 - With the "finish" and "return" commands, the return value for functions
5668 returning a small array is now correctly printed.
5669 - It is now possible to break on shared library code which gets executed
5670 during a shared library init phase (code executed while executing
5671 their .init section). Previously, the breakpoint would have no effect.
5672 - GDB is now able to backtrace through the signal handler for
5673 non-threaded programs.
5675 PIE (Position Independent Executable) programs debugging is now supported.
5676 This includes debugging execution of PIC (Position Independent Code) shared
5677 libraries although for that, it should be possible to run such libraries as an
5680 *** Changes in GDB 7.0
5682 * GDB now has an interface for JIT compilation. Applications that
5683 dynamically generate code can create symbol files in memory and register
5684 them with GDB. For users, the feature should work transparently, and
5685 for JIT developers, the interface is documented in the GDB manual in the
5686 "JIT Compilation Interface" chapter.
5688 * Tracepoints may now be conditional. The syntax is as for
5689 breakpoints; either an "if" clause appended to the "trace" command,
5690 or the "condition" command is available. GDB sends the condition to
5691 the target for evaluation using the same bytecode format as is used
5692 for tracepoint actions.
5694 * The disassemble command now supports: an optional /r modifier, print the
5695 raw instructions in hex as well as in symbolic form, and an optional /m
5696 modifier to print mixed source+assembly.
5698 * Process record and replay
5700 In a architecture environment that supports ``process record and
5701 replay'', ``process record and replay'' target can record a log of
5702 the process execution, and replay it with both forward and reverse
5705 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5706 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5707 set execution-direction {forward|reverse}, for targets that support
5710 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5711 feature is available with a native GDB running on kernel version
5714 * GDB now has support for multi-byte and wide character sets on the
5715 target. Strings whose character type is wchar_t, char16_t, or
5716 char32_t are now correctly printed. GDB supports wide- and unicode-
5717 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5718 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5719 `printf'. This feature requires iconv to work properly; if your
5720 system does not have a working iconv, GDB can use GNU libiconv. See
5721 the installation instructions for more information.
5723 * GDB now supports automatic retrieval of shared library files from
5724 remote targets. To use this feature, specify a system root that begins
5725 with the `remote:' prefix, either via the `set sysroot' command or via
5726 the `--with-sysroot' configure-time option.
5728 * "info sharedlibrary" now takes an optional regex of libraries to show,
5729 and it now reports if a shared library has no debugging information.
5731 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5732 now complete on file names.
5734 * When completing in expressions, gdb will attempt to limit
5735 completions to allowable structure or union fields, where appropriate.
5736 For instance, consider:
5738 # struct example { int f1; double f2; };
5739 # struct example variable;
5742 If the user types TAB at the end of this command line, the available
5743 completions will be "f1" and "f2".
5745 * Inlined functions are now supported. They show up in backtraces, and
5746 the "step", "next", and "finish" commands handle them automatically.
5748 * GDB now supports the token-splicing (##) and stringification (#)
5749 operators when expanding macros. It also supports variable-arity
5752 * GDB now supports inspecting extra signal information, exported by
5753 the new $_siginfo convenience variable. The feature is currently
5754 implemented on linux ARM, i386 and amd64.
5756 * GDB can now display the VFP floating point registers and NEON vector
5757 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5758 can provide these registers (requires Linux 2.6.30 or later). Remote
5759 and simulator targets may also provide them.
5761 * New remote packets
5764 Search memory for a sequence of bytes.
5767 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5768 operation over reliable transport links. Use of this packet is
5769 controlled by the `set remote noack-packet' command.
5772 Kill the process with the specified process ID. Use this in preference
5773 to `k' when multiprocess protocol extensions are supported.
5776 Obtains additional operating system information
5780 Read or write additional signal information.
5782 * Removed remote protocol undocumented extension
5784 An undocumented extension to the remote protocol's `S' stop reply
5785 packet that permitted the stub to pass a process id was removed.
5786 Remote servers should use the `T' stop reply packet instead.
5788 * GDB now supports multiple function calling conventions according to the
5789 DWARF-2 DW_AT_calling_convention function attribute.
5791 * The SH target utilizes the aforementioned change to distinguish between gcc
5792 and Renesas calling convention. It also adds the new CLI commands
5793 `set/show sh calling-convention'.
5795 * GDB can now read compressed debug sections, as produced by GNU gold
5796 with the --compress-debug-sections=zlib flag.
5798 * 64-bit core files are now supported on AIX.
5800 * Thread switching is now supported on Tru64.
5802 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5803 which will be allocated using malloc later in program execution.
5805 * The qXfer:libraries:read remote protocol packet now allows passing a
5806 list of section offsets.
5808 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5809 conditions handling signals delivered during attach or thread creation
5810 have also been fixed.
5812 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5813 From the user's standpoint, all unqualified instances of True and False
5814 are treated as the standard definitions, regardless of context.
5816 * GDB now parses C++ symbol and type names more flexibly. For
5819 template<typename T> class C { };
5822 GDB will now correctly handle all of:
5824 ptype C<char const *>
5825 ptype C<char const*>
5826 ptype C<const char *>
5827 ptype C<const char*>
5829 * New features in the GDB remote stub, gdbserver
5831 - The "--wrapper" command-line argument tells gdbserver to use a
5832 wrapper program to launch programs for debugging.
5834 - On PowerPC and S/390 targets, it is now possible to use a single
5835 gdbserver executable to debug both 32-bit and 64-bit programs.
5836 (This requires gdbserver itself to be built as a 64-bit executable.)
5838 - gdbserver uses the new noack protocol mode for TCP connections to
5839 reduce communications latency, if also supported and enabled in GDB.
5841 - Support for the sparc64-linux-gnu target is now included in
5844 - The amd64-linux build of gdbserver now supports debugging both
5845 32-bit and 64-bit programs.
5847 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5848 now support hardware watchpoints, and will use them automatically
5853 GDB now has support for scripting using Python. Whether this is
5854 available is determined at configure time.
5856 New GDB commands can now be written in Python.
5858 * Ada tasking support
5860 Ada tasks can now be inspected in GDB. The following commands have
5864 Print the list of Ada tasks.
5866 Print detailed information about task number N.
5868 Print the task number of the current task.
5870 Switch the context of debugging to task number N.
5872 * Support for user-defined prefixed commands. The "define" command can
5873 add new commands to existing prefixes, e.g. "target".
5875 * Multi-inferior, multi-process debugging.
5877 GDB now has generalized support for multi-inferior debugging. See
5878 "Debugging Multiple Inferiors" in the manual for more information.
5879 Although availability still depends on target support, the command
5880 set is more uniform now. The GNU/Linux specific multi-forks support
5881 has been migrated to this new framework. This implied some user
5882 visible changes; see "New commands" and also "Removed commands"
5885 * Target descriptions can now describe the target OS ABI. See the
5886 "Target Description Format" section in the user manual for more
5889 * Target descriptions can now describe "compatible" architectures
5890 to indicate that the target can execute applications for a different
5891 architecture in addition to those for the main target architecture.
5892 See the "Target Description Format" section in the user manual for
5895 * Multi-architecture debugging.
5897 GDB now includes general supports for debugging applications on
5898 hybrid systems that use more than one single processor architecture
5899 at the same time. Each such hybrid architecture still requires
5900 specific support to be added. The only hybrid architecture supported
5901 in this version of GDB is the Cell Broadband Engine.
5903 * GDB now supports integrated debugging of Cell/B.E. applications that
5904 use both the PPU and SPU architectures. To enable support for hybrid
5905 Cell/B.E. debugging, you need to configure GDB to support both the
5906 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5907 --enable-targets configure option.
5909 * Non-stop mode debugging.
5911 For some targets, GDB now supports an optional mode of operation in
5912 which you can examine stopped threads while other threads continue
5913 to execute freely. This is referred to as non-stop mode, with the
5914 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5915 section in the user manual for more information.
5917 To be able to support remote non-stop debugging, a remote stub needs
5918 to implement the non-stop mode remote protocol extensions, as
5919 described in the "Remote Non-Stop" section of the user manual. The
5920 GDB remote stub, gdbserver, has been adjusted to support these
5921 extensions on linux targets.
5923 * New commands (for set/show, see "New options" below)
5925 catch syscall [NAME(S) | NUMBER(S)]
5926 Catch system calls. Arguments, which should be names of system
5927 calls or their numbers, mean catch only those syscalls. Without
5928 arguments, every syscall will be caught. When the inferior issues
5929 any of the specified syscalls, GDB will stop and announce the system
5930 call, both when it is called and when its call returns. This
5931 feature is currently available with a native GDB running on the
5932 Linux Kernel, under the following architectures: x86, x86_64,
5933 PowerPC and PowerPC64.
5935 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5937 Search memory for a sequence of bytes.
5939 maint set python print-stack
5940 maint show python print-stack
5941 Show a stack trace when an error is encountered in a Python script.
5944 Invoke CODE by passing it to the Python interpreter.
5949 These allow macros to be defined, undefined, and listed
5953 Show operating system information about processes.
5956 List the inferiors currently under GDB's control.
5959 Switch focus to inferior number NUM.
5962 Detach from inferior number NUM.
5965 Kill inferior number NUM.
5969 set spu stop-on-load
5970 show spu stop-on-load
5971 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5973 set spu auto-flush-cache
5974 show spu auto-flush-cache
5975 Control whether to automatically flush the software-managed cache
5976 during Cell/B.E. debugging.
5978 set sh calling-convention
5979 show sh calling-convention
5980 Control the calling convention used when calling SH target functions.
5983 show debug timestamp
5984 Control display of timestamps with GDB debugging output.
5986 set disassemble-next-line
5987 show disassemble-next-line
5988 Control display of disassembled source lines or instructions when
5991 set remote noack-packet
5992 show remote noack-packet
5993 Set/show the use of remote protocol QStartNoAckMode packet. See above
5994 under "New remote packets."
5996 set remote query-attached-packet
5997 show remote query-attached-packet
5998 Control use of remote protocol `qAttached' (query-attached) packet.
6000 set remote read-siginfo-object
6001 show remote read-siginfo-object
6002 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
6005 set remote write-siginfo-object
6006 show remote write-siginfo-object
6007 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
6010 set remote reverse-continue
6011 show remote reverse-continue
6012 Control use of remote protocol 'bc' (reverse-continue) packet.
6014 set remote reverse-step
6015 show remote reverse-step
6016 Control use of remote protocol 'bs' (reverse-step) packet.
6018 set displaced-stepping
6019 show displaced-stepping
6020 Control displaced stepping mode. Displaced stepping is a way to
6021 single-step over breakpoints without removing them from the debuggee.
6022 Also known as "out-of-line single-stepping".
6025 show debug displaced
6026 Control display of debugging info for displaced stepping.
6028 maint set internal-error
6029 maint show internal-error
6030 Control what GDB does when an internal error is detected.
6032 maint set internal-warning
6033 maint show internal-warning
6034 Control what GDB does when an internal warning is detected.
6039 Use a wrapper program to launch programs for debugging.
6041 set multiple-symbols (all|ask|cancel)
6042 show multiple-symbols
6043 The value of this variable can be changed to adjust the debugger behavior
6044 when an expression or a breakpoint location contains an ambiguous symbol
6045 name (an overloaded function name, for instance).
6047 set breakpoint always-inserted
6048 show breakpoint always-inserted
6049 Keep breakpoints always inserted in the target, as opposed to inserting
6050 them when resuming the target, and removing them when the target stops.
6051 This option can improve debugger performance on slow remote targets.
6053 set arm fallback-mode (arm|thumb|auto)
6054 show arm fallback-mode
6055 set arm force-mode (arm|thumb|auto)
6057 These commands control how ARM GDB determines whether instructions
6058 are ARM or Thumb. The default for both settings is auto, which uses
6059 the current CPSR value for instructions without symbols; previous
6060 versions of GDB behaved as if "set arm fallback-mode arm".
6062 set arm unwind-secure-frames
6063 Enable unwinding from Non-secure to Secure mode on Cortex-M with
6065 This can trigger security exceptions when unwinding exception stacks.
6067 set disable-randomization
6068 show disable-randomization
6069 Standalone programs run with the virtual address space randomization enabled
6070 by default on some platforms. This option keeps the addresses stable across
6071 multiple debugging sessions.
6075 Control whether other threads are stopped or not when some thread hits
6080 Requests that asynchronous execution is enabled in the target, if available.
6081 In this case, it's possible to resume target in the background, and interact
6082 with GDB while the target is running. "show target-async" displays the
6083 current state of asynchronous execution of the target.
6085 set target-wide-charset
6086 show target-wide-charset
6087 The target-wide-charset is the name of the character set that GDB
6088 uses when printing characters whose type is wchar_t.
6090 set tcp auto-retry (on|off)
6092 set tcp connect-timeout
6093 show tcp connect-timeout
6094 These commands allow GDB to retry failed TCP connections to a remote stub
6095 with a specified timeout period; this is useful if the stub is launched
6096 in parallel with GDB but may not be ready to accept connections immediately.
6098 set libthread-db-search-path
6099 show libthread-db-search-path
6100 Control list of directories which GDB will search for appropriate
6103 set schedule-multiple (on|off)
6104 show schedule-multiple
6105 Allow GDB to resume all threads of all processes or only threads of
6106 the current process.
6110 Use more aggressive caching for accesses to the stack. This improves
6111 performance of remote debugging (particularly backtraces) without
6112 affecting correctness.
6114 set interactive-mode (on|off|auto)
6115 show interactive-mode
6116 Control whether GDB runs in interactive mode (on) or not (off).
6117 When in interactive mode, GDB waits for the user to answer all
6118 queries. Otherwise, GDB does not wait and assumes the default
6119 answer. When set to auto (the default), GDB determines which
6120 mode to use based on the stdin settings.
6125 For program forks, this is replaced by the new more generic `info
6126 inferiors' command. To list checkpoints, you can still use the
6127 `info checkpoints' command, which was an alias for the `info forks'
6131 Replaced by the new `inferior' command. To switch between
6132 checkpoints, you can still use the `restart' command, which was an
6133 alias for the `fork' command.
6136 This is removed, since some targets don't have a notion of
6137 processes. To switch between processes, you can still use the
6138 `inferior' command using GDB's own inferior number.
6141 For program forks, this is replaced by the new more generic `kill
6142 inferior' command. To delete a checkpoint, you can still use the
6143 `delete checkpoint' command, which was an alias for the `delete
6147 For program forks, this is replaced by the new more generic `detach
6148 inferior' command. To detach a checkpoint, you can still use the
6149 `detach checkpoint' command, which was an alias for the `detach
6152 * New native configurations
6154 x86/x86_64 Darwin i[34567]86-*-darwin*
6156 x86_64 MinGW x86_64-*-mingw*
6160 Lattice Mico32 lm32-*
6161 x86 DICOS i[34567]86-*-dicos*
6162 x86_64 DICOS x86_64-*-dicos*
6165 * The GDB remote stub, gdbserver, now supports x86 Windows CE
6166 (mingw32ce) debugging.
6172 These commands were actually not implemented on any target.
6174 *** Changes in GDB 6.8
6176 * New native configurations
6178 NetBSD/hppa hppa*-*netbsd*
6179 Xtensa GNU/Linux xtensa*-*-linux*
6183 NetBSD/hppa hppa*-*-netbsd*
6184 Xtensa GNU/Linux xtensa*-*-linux*
6186 * Change in command line behavior -- corefiles vs. process ids.
6188 When the '-p NUMBER' or '--pid NUMBER' options are used, and
6189 attaching to process NUMBER fails, GDB no longer attempts to open a
6190 core file named NUMBER. Attaching to a program using the -c option
6191 is no longer supported. Instead, use the '-p' or '--pid' options.
6193 * GDB can now be built as a native debugger for debugging Windows x86
6194 (mingw32) Portable Executable (PE) programs.
6196 * Pending breakpoints no longer change their number when their address
6199 * GDB now supports breakpoints with multiple locations,
6200 including breakpoints on C++ constructors, inside C++ templates,
6201 and in inlined functions.
6203 * GDB's ability to debug optimized code has been improved. GDB more
6204 accurately identifies function bodies and lexical blocks that occupy
6205 more than one contiguous range of addresses.
6207 * Target descriptions can now describe registers for PowerPC.
6209 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
6210 registers on PowerPC targets.
6212 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
6213 targets even when the libthread_db library is not available.
6215 * The GDB remote stub, gdbserver, now supports the new file transfer
6216 commands (remote put, remote get, and remote delete).
6218 * The GDB remote stub, gdbserver, now supports run and attach in
6219 extended-remote mode.
6221 * hppa*64*-*-hpux11* target broken
6222 The debugger is unable to start a program and fails with the following
6223 error: "Error trying to get information about dynamic linker".
6224 The gdb-6.7 release is also affected.
6226 * GDB now supports the --enable-targets= configure option to allow
6227 building a single GDB executable that supports multiple remote
6228 target architectures.
6230 * GDB now supports debugging C and C++ programs which use the
6231 Decimal Floating Point extension. In addition, the PowerPC target
6232 now has a set of pseudo-registers to inspect decimal float values
6233 stored in two consecutive float registers.
6235 * The -break-insert MI command can optionally create pending
6238 * Improved support for debugging Ada
6239 Many improvements to the Ada language support have been made. These
6241 - Better support for Ada2005 interface types
6242 - Improved handling of arrays and slices in general
6243 - Better support for Taft-amendment types
6244 - The '{type} ADDRESS' expression is now allowed on the left hand-side
6246 - Improved command completion in Ada
6249 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
6254 set print frame-arguments (all|scalars|none)
6255 show print frame-arguments
6256 The value of this variable can be changed to control which argument
6257 values should be printed by the debugger when displaying a frame.
6262 Transfer files to and from a remote target, and delete remote files.
6269 Transfer files to and from a remote target, and delete remote files.
6271 * New remote packets
6278 Open, close, read, write, and delete files on the remote system.
6281 Attach to an existing process on the remote system, in extended-remote
6285 Run a new process on the remote system, in extended-remote mode.
6287 *** Changes in GDB 6.7
6289 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
6290 bfd, libiberty and opcodes, as revealed by static analysis donated by
6291 Coverity, Inc. (http://scan.coverity.com).
6293 * When looking up multiply-defined global symbols, GDB will now prefer the
6294 symbol definition in the current shared library if it was built using the
6295 -Bsymbolic linker option.
6297 * When the Text User Interface (TUI) is not configured, GDB will now
6298 recognize the -tui command-line option and print a message that the TUI
6301 * The GDB remote stub, gdbserver, now has lower overhead for high
6302 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
6304 * GDB for MIPS targets now autodetects whether a remote target provides
6305 32-bit or 64-bit register values.
6307 * Support for C++ member pointers has been improved.
6309 * GDB now understands XML target descriptions, which specify the
6310 target's overall architecture. GDB can read a description from
6311 a local file or over the remote serial protocol.
6313 * Vectors of single-byte data use a new integer type which is not
6314 automatically displayed as character or string data.
6316 * The /s format now works with the print command. It displays
6317 arrays of single-byte integers and pointers to single-byte integers
6320 * Target descriptions can now describe target-specific registers,
6321 for architectures which have implemented the support (currently
6322 only ARM, M68K, and MIPS).
6324 * GDB and the GDB remote stub, gdbserver, now support the XScale
6327 * The GDB remote stub, gdbserver, has been updated to support
6328 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6329 has been rewritten to use the standard GDB remote protocol.
6331 * GDB can now step into C++ functions which are called through thunks.
6333 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6335 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6336 layout. It also supports a TextSeg= and DataSeg= response when only
6337 segment base addresses (rather than offsets) are available.
6339 * The /i format now outputs any trailing branch delay slot instructions
6340 immediately following the last instruction within the count specified.
6342 * The GDB remote protocol "T" stop reply packet now supports a
6343 "library" response. Combined with the new "qXfer:libraries:read"
6344 packet, this response allows GDB to debug shared libraries on targets
6345 where the operating system manages the list of loaded libraries (e.g.
6346 Windows and SymbianOS).
6348 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6349 (DLLs) on Windows and Windows CE targets.
6351 * GDB now supports a faster verification that a .debug file matches its binary
6352 according to its build-id signature, if the signature is present.
6358 Enable or disable hardware flow control (RTS/CTS) on the serial port
6359 when debugging using remote targets.
6361 set mem inaccessible-by-default
6362 show mem inaccessible-by-default
6363 If the target supplies a memory map, for instance via the remote
6364 protocol's "qXfer:memory-map:read" packet, setting this variable
6365 prevents GDB from accessing memory outside the memory map. This
6366 is useful for targets with memory mapped registers or which react
6367 badly to accesses of unmapped address space.
6369 set breakpoint auto-hw
6370 show breakpoint auto-hw
6371 If the target supplies a memory map, for instance via the remote
6372 protocol's "qXfer:memory-map:read" packet, setting this variable
6373 lets GDB use hardware breakpoints automatically for memory regions
6374 where it can not use software breakpoints. This covers both the
6375 "break" command and internal breakpoints used for other commands
6376 including "next" and "finish".
6379 catch exception unhandled
6380 Stop the program execution when Ada exceptions are raised.
6383 Stop the program execution when an Ada assertion failed.
6387 Set an alternate system root for target files. This is a more
6388 general version of "set solib-absolute-prefix", which is now
6389 an alias to "set sysroot".
6392 Provide extended SPU facility status information. This set of
6393 commands is available only when debugging the Cell/B.E. SPU
6396 * New native configurations
6398 OpenBSD/sh sh*-*openbsd*
6401 unset tdesc filename
6403 Use the specified local file as an XML target description, and do
6404 not query the target for its built-in description.
6408 OpenBSD/sh sh*-*-openbsd*
6409 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
6410 Toshiba Media Processor mep-elf
6412 * New remote packets
6415 Ignore the specified signals; pass them directly to the debugged program
6416 without stopping other threads or reporting them to GDB.
6418 qXfer:features:read:
6419 Read an XML target description from the target, which describes its
6424 Read or write contents of an spufs file on the target system. These
6425 packets are available only on the Cell/B.E. SPU architecture.
6427 qXfer:libraries:read:
6428 Report the loaded shared libraries. Combined with new "T" packet
6429 response, this packet allows GDB to debug shared libraries on
6430 targets where the operating system manages the list of loaded
6431 libraries (e.g. Windows and SymbianOS).
6435 Support for these obsolete configurations has been removed.
6443 i[34567]86-*-lynxos*
6444 i[34567]86-*-netware*
6445 i[34567]86-*-sco3.2v5*
6446 i[34567]86-*-sco3.2v4*
6448 i[34567]86-*-sysv4.2*
6451 i[34567]86-*-unixware2*
6452 i[34567]86-*-unixware*
6461 * Other removed features
6468 Various m68k-only ROM monitors.
6475 Various Renesas ROM monitors and debugging interfaces for SH and
6480 Support for a Macraigor serial interface to on-chip debugging.
6481 GDB does not directly support the newer parallel or USB
6486 A debug information format. The predecessor to DWARF 2 and
6487 DWARF 3, which are still supported.
6489 Support for the HP aCC compiler on HP-UX/PA-RISC
6491 SOM-encapsulated symbolic debugging information, automatic
6492 invocation of pxdb, and the aCC custom C++ ABI. This does not
6493 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6494 with aCC can still be debugged on an assembly level.
6496 MIPS ".pdr" sections
6498 A MIPS-specific format used to describe stack frame layout
6499 in debugging information.
6503 GDB could work with an older version of Guile to debug
6504 the interpreter and Scheme programs running in it.
6506 set mips stack-arg-size
6507 set mips saved-gpreg-size
6509 Use "set mips abi" to control parameter passing for MIPS.
6511 *** Changes in GDB 6.6
6516 Cell Broadband Engine SPU spu-elf
6518 * GDB can now be configured as a cross-debugger targeting native Windows
6519 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6520 running on a Windows system over TCP/IP to debug Windows programs.
6522 * The GDB remote stub, gdbserver, has been updated to support Windows and
6523 Cygwin debugging. Both single-threaded and multi-threaded programs are
6526 * The "set trust-readonly-sections" command works again. This command was
6527 broken in GDB 6.3, 6.4, and 6.5.
6529 * The "load" command now supports writing to flash memory, if the remote
6530 stub provides the required support.
6532 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
6533 longer requires symbolic debug information (e.g. DWARF-2).
6538 unset substitute-path
6539 show substitute-path
6540 Manage a list of substitution rules that GDB uses to rewrite the name
6541 of the directories where the sources are located. This can be useful
6542 for instance when the sources were moved to a different location
6543 between compilation and debugging.
6547 Print each CLI command as it is executed. Each command is prefixed with
6548 a number of `+' symbols representing the nesting depth.
6549 The source command now has a `-v' option to enable the same feature.
6553 The ARM Demon monitor support (RDP protocol, "target rdp").
6555 Kernel Object Display, an embedded debugging feature which only worked with
6556 an obsolete version of Cisco IOS.
6558 The 'set download-write-size' and 'show download-write-size' commands.
6560 * New remote packets
6563 Tell a stub about GDB client features, and request remote target features.
6564 The first feature implemented is PacketSize, which allows the target to
6565 specify the size of packets it can handle - to minimize the number of
6566 packets required and improve performance when connected to a remote
6570 Fetch an OS auxilliary vector from the remote stub. This packet is a
6571 more efficient replacement for qPart:auxv:read.
6573 qXfer:memory-map:read:
6574 Fetch a memory map from the remote stub, including information about
6575 RAM, ROM, and flash memory devices.
6580 Erase and program a flash memory device.
6582 * Removed remote packets
6585 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
6586 used it, and only gdbserver implemented it.
6588 *** Changes in GDB 6.5
6592 Renesas M32C/M16C m32c-elf
6594 Morpho Technologies ms1 ms1-elf
6598 init-if-undefined Initialize a convenience variable, but
6599 only if it doesn't already have a value.
6601 The following commands are presently only implemented for native GNU/Linux:
6603 checkpoint Save a snapshot of the program state.
6605 restart <n> Return the program state to a
6606 previously saved state.
6608 info checkpoints List currently saved checkpoints.
6610 delete-checkpoint <n> Delete a previously saved checkpoint.
6612 set|show detach-on-fork Tell gdb whether to detach from a newly
6613 forked process, or to keep debugging it.
6615 info forks List forks of the user program that
6616 are available to be debugged.
6618 fork <n> Switch to debugging one of several
6619 forks of the user program that are
6620 available to be debugged.
6622 delete-fork <n> Delete a fork from the list of forks
6623 that are available to be debugged (and
6624 kill the forked process).
6626 detach-fork <n> Delete a fork from the list of forks
6627 that are available to be debugged (and
6628 allow the process to continue).
6632 Morpho Technologies ms2 ms1-elf
6634 * Improved Windows host support
6636 GDB now builds as a cross debugger hosted on i686-mingw32, including
6637 native console support, and remote communications using either
6638 network sockets or serial ports.
6640 * Improved Modula-2 language support
6642 GDB can now print most types in the Modula-2 syntax. This includes:
6643 basic types, set types, record types, enumerated types, range types,
6644 pointer types and ARRAY types. Procedure var parameters are correctly
6645 printed and hexadecimal addresses and character constants are also
6646 written in the Modula-2 syntax. Best results can be obtained by using
6647 GNU Modula-2 together with the -gdwarf-2 command line option.
6651 The ARM rdi-share module.
6653 The Netware NLM debug server.
6655 *** Changes in GDB 6.4
6657 * New native configurations
6659 OpenBSD/arm arm*-*-openbsd*
6660 OpenBSD/mips64 mips64-*-openbsd*
6664 Morpho Technologies ms1 ms1-elf
6666 * New command line options
6668 --batch-silent As for --batch, but totally silent.
6669 --return-child-result The debugger will exist with the same value
6670 the child (debugged) program exited with.
6671 --eval-command COMMAND, -ex COMMAND
6672 Execute a single GDB CLI command. This may be
6673 specified multiple times and in conjunction
6674 with the --command (-x) option.
6676 * Deprecated commands removed
6678 The following commands, that were deprecated in 2000, have been
6682 set|show arm disassembly-flavor set|show arm disassembler
6683 othernames set arm disassembler
6684 set|show remotedebug set|show debug remote
6685 set|show archdebug set|show debug arch
6686 set|show eventdebug set|show debug event
6689 * New BSD user-level threads support
6691 It is now possible to debug programs using the user-level threads
6692 library on OpenBSD and FreeBSD. Currently supported (target)
6695 FreeBSD/amd64 x86_64-*-freebsd*
6696 FreeBSD/i386 i386-*-freebsd*
6697 OpenBSD/i386 i386-*-openbsd*
6699 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6700 are not yet supported.
6702 * New support for Matsushita MN10300 w/sim added
6703 (Work in progress). mn10300-elf.
6705 * REMOVED configurations and files
6707 VxWorks and the XDR protocol *-*-vxworks
6708 Motorola MCORE mcore-*-*
6709 National Semiconductor NS32000 ns32k-*-*
6711 * New "set print array-indexes" command
6713 After turning this setting "on", GDB prints the index of each element
6714 when displaying arrays. The default is "off" to preserve the previous
6717 * VAX floating point support
6719 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6721 * User-defined command support
6723 In addition to using $arg0..$arg9 for argument passing, it is now possible
6724 to use $argc to determine now many arguments have been passed. See the
6725 section on user-defined commands in the user manual for more information.
6727 *** Changes in GDB 6.3:
6729 * New command line option
6731 GDB now accepts -l followed by a number to set the timeout for remote
6734 * GDB works with GCC -feliminate-dwarf2-dups
6736 GDB now supports a more compact representation of DWARF-2 debug
6737 information using DW_FORM_ref_addr references. These are produced
6738 by GCC with the option -feliminate-dwarf2-dups and also by some
6739 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6740 to use -feliminate-dwarf2-dups.
6742 * Internationalization
6744 When supported by the host system, GDB will be built with
6745 internationalization (libintl). The task of marking up the sources is
6746 continued, we're looking forward to our first translation.
6750 Initial support for debugging programs compiled with the GNAT
6751 implementation of the Ada programming language has been integrated
6752 into GDB. In this release, support is limited to expression evaluation.
6754 * New native configurations
6756 GNU/Linux/m32r m32r-*-linux-gnu
6760 GDB's remote protocol now includes support for the 'p' packet. This
6761 packet is used to fetch individual registers from a remote inferior.
6763 * END-OF-LIFE registers[] compatibility module
6765 GDB's internal register infrastructure has been completely rewritten.
6766 The new infrastructure making possible the implementation of key new
6767 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6770 GDB 6.3 will be the last release to include the registers[]
6771 compatibility module that allowed out-of-date configurations to
6772 continue to work. This change directly impacts the following
6782 powerpc bdm protocol
6784 Unless there is activity to revive these configurations, they will be
6785 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6787 * OBSOLETE configurations and files
6789 Configurations that have been declared obsolete in this release have
6790 been commented out. Unless there is activity to revive these
6791 configurations, the next release of GDB will have their sources
6792 permanently REMOVED.
6801 *** Changes in GDB 6.2.1:
6803 * MIPS `break main; run' gave an heuristic-fence-post warning
6805 When attempting to run even a simple program, a warning about
6806 heuristic-fence-post being hit would be reported. This problem has
6809 * MIPS IRIX 'long double' crashed GDB
6811 When examining a long double variable, GDB would get a segmentation
6812 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6813 IRIX long double values).
6817 A bug in the VAX stack code was causing problems with the "next"
6818 command. This problem has been fixed.
6820 *** Changes in GDB 6.2:
6822 * Fix for ``many threads''
6824 On GNU/Linux systems that use the NPTL threads library, a program
6825 rapidly creating and deleting threads would confuse GDB leading to the
6828 ptrace: No such process.
6829 thread_db_get_info: cannot get thread info: generic error
6831 This problem has been fixed.
6833 * "-async" and "-noasync" options removed.
6835 Support for the broken "-noasync" option has been removed (it caused
6838 * New ``start'' command.
6840 This command runs the program until the beginning of the main procedure.
6842 * New BSD Kernel Data Access Library (libkvm) interface
6844 Using ``target kvm'' it is now possible to debug kernel core dumps and
6845 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6846 platforms. Currently supported (native-only) configurations are:
6848 FreeBSD/amd64 x86_64-*-freebsd*
6849 FreeBSD/i386 i?86-*-freebsd*
6850 NetBSD/i386 i?86-*-netbsd*
6851 NetBSD/m68k m68*-*-netbsd*
6852 NetBSD/sparc sparc-*-netbsd*
6853 OpenBSD/amd64 x86_64-*-openbsd*
6854 OpenBSD/i386 i?86-*-openbsd*
6855 OpenBSD/m68k m68*-openbsd*
6856 OpenBSD/sparc sparc-*-openbsd*
6858 * Signal trampoline code overhauled
6860 Many generic problems with GDB's signal handling code have been fixed.
6861 These include: backtraces through non-contiguous stacks; recognition
6862 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6863 call; backtrace through a signal trampoline; step into and out of
6864 signal handlers; and single-stepping in the signal trampoline.
6866 Please note that kernel bugs are a limiting factor here. These
6867 features have been shown to work on an s390 GNU/Linux system that
6868 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6870 * Cygwin support for DWARF 2 added.
6872 * New native configurations
6874 GNU/Linux/hppa hppa*-*-linux*
6875 OpenBSD/hppa hppa*-*-openbsd*
6876 OpenBSD/m68k m68*-*-openbsd*
6877 OpenBSD/m88k m88*-*-openbsd*
6878 OpenBSD/powerpc powerpc-*-openbsd*
6879 NetBSD/vax vax-*-netbsd*
6880 OpenBSD/vax vax-*-openbsd*
6882 * END-OF-LIFE frame compatibility module
6884 GDB's internal frame infrastructure has been completely rewritten.
6885 The new infrastructure making it possible to support key new features
6886 including DWARF 2 Call Frame Information. To aid in the task of
6887 migrating old configurations to this new infrastructure, a
6888 compatibility module, that allowed old configurations to continue to
6889 work, was also included.
6891 GDB 6.2 will be the last release to include this frame compatibility
6892 module. This change directly impacts the following configurations:
6902 Unless there is activity to revive these configurations, they will be
6903 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6905 * REMOVED configurations and files
6907 Sun 3, running SunOS 3 m68*-*-sunos3*
6908 Sun 3, running SunOS 4 m68*-*-sunos4*
6909 Sun 2, running SunOS 3 m68000-*-sunos3*
6910 Sun 2, running SunOS 4 m68000-*-sunos4*
6911 Motorola 680x0 running LynxOS m68*-*-lynxos*
6912 AT&T 3b1/Unix pc m68*-att-*
6913 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6914 decstation mips-dec-* mips-little-*
6915 riscos mips-*-riscos* mips-*-sysv*
6916 sonymips mips-sony-*
6917 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6919 *** Changes in GDB 6.1.1:
6921 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6923 The TUI (Text-mode User Interface) is now built as part of a default
6924 GDB configuration. It is enabled by either selecting the TUI with the
6925 command line option "-i=tui" or by running the separate "gdbtui"
6926 program. For more information on the TUI, see the manual "Debugging
6929 * Pending breakpoint support (also included in GDB 6.1)
6931 Support has been added to allow you to specify breakpoints in shared
6932 libraries that have not yet been loaded. If a breakpoint location
6933 cannot be found, and the "breakpoint pending" option is set to auto,
6934 GDB queries you if you wish to make the breakpoint pending on a future
6935 shared-library load. If and when GDB resolves the breakpoint symbol,
6936 the pending breakpoint is removed as one or more regular breakpoints
6939 Pending breakpoints are very useful for GCJ Java debugging.
6941 * Fixed ISO-C build problems
6943 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6944 non ISO-C code that stopped them being built using a more strict ISO-C
6945 compiler (e.g., IBM's C compiler).
6947 * Fixed build problem on IRIX 5
6949 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6950 wasn't able to compile compile on an IRIX 5 system.
6952 * Added execute permission to gdb/gdbserver/configure
6954 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6955 permission. This bug would cause configure to fail on a number of
6956 systems (Solaris, IRIX). Ref: server/519.
6958 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6960 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6961 has been updated to use constant array sizes.
6963 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6965 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6966 its generated DWARF Call Frame Info. This encoding was causing GDB to
6967 panic, that panic has been fixed. Ref: gdb/1628.
6969 * Fixed a problem when examining parameters in shared library code.
6971 When examining parameters in optimized shared library code generated
6972 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6973 not available''. GDB now correctly displays the variable's value.
6975 *** Changes in GDB 6.1:
6977 * Removed --with-mmalloc
6979 Support for the mmalloc memory manager has been removed, as it
6980 conflicted with the internal gdb byte cache.
6982 * Changes in AMD64 configurations
6984 The AMD64 target now includes the %cs and %ss registers. As a result
6985 the AMD64 remote protocol has changed; this affects the floating-point
6986 and SSE registers. If you rely on those registers for your debugging,
6987 you should upgrade gdbserver on the remote side.
6989 * Revised SPARC target
6991 The SPARC target has been completely revised, incorporating the
6992 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6993 support for LynxOS and SunOS 4 has been dropped. Calling functions
6994 from within GDB on operating systems with a non-executable stack
6995 (Solaris, OpenBSD) now works.
6999 GDB has a new C++ demangler which does a better job on the mangled
7000 names generated by current versions of g++. It also runs faster, so
7001 with this and other changes gdb should now start faster on large C++
7004 * DWARF 2 Location Expressions
7006 GDB support for location expressions has been extended to support function
7007 arguments and frame bases. Older versions of GDB could crash when they
7010 * C++ nested types and namespaces
7012 GDB's support for nested types and namespaces in C++ has been
7013 improved, especially if you use the DWARF 2 debugging format. (This
7014 is the default for recent versions of GCC on most platforms.)
7015 Specifically, if you have a class "Inner" defined within a class or
7016 namespace "Outer", then GDB realizes that the class's name is
7017 "Outer::Inner", not simply "Inner". This should greatly reduce the
7018 frequency of complaints about not finding RTTI symbols. In addition,
7019 if you are stopped at inside of a function defined within a namespace,
7020 GDB modifies its name lookup accordingly.
7022 * New native configurations
7024 NetBSD/amd64 x86_64-*-netbsd*
7025 OpenBSD/amd64 x86_64-*-openbsd*
7026 OpenBSD/alpha alpha*-*-openbsd*
7027 OpenBSD/sparc sparc-*-openbsd*
7028 OpenBSD/sparc64 sparc64-*-openbsd*
7030 * New debugging protocols
7032 M32R with SDI protocol m32r-*-elf*
7034 * "set prompt-escape-char" command deleted.
7036 The command "set prompt-escape-char" has been deleted. This command,
7037 and its very obscure effect on GDB's prompt, was never documented,
7038 tested, nor mentioned in the NEWS file.
7040 * OBSOLETE configurations and files
7042 Configurations that have been declared obsolete in this release have
7043 been commented out. Unless there is activity to revive these
7044 configurations, the next release of GDB will have their sources
7045 permanently REMOVED.
7047 Sun 3, running SunOS 3 m68*-*-sunos3*
7048 Sun 3, running SunOS 4 m68*-*-sunos4*
7049 Sun 2, running SunOS 3 m68000-*-sunos3*
7050 Sun 2, running SunOS 4 m68000-*-sunos4*
7051 Motorola 680x0 running LynxOS m68*-*-lynxos*
7052 AT&T 3b1/Unix pc m68*-att-*
7053 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
7054 decstation mips-dec-* mips-little-*
7055 riscos mips-*-riscos* mips-*-sysv*
7056 sonymips mips-sony-*
7057 sysv mips*-*-sysv4* (IRIX 5/6 not included)
7059 * REMOVED configurations and files
7061 SGI Irix-4.x mips-sgi-irix4 or iris4
7062 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7063 Z8000 simulator z8k-zilog-none or z8ksim
7064 Matsushita MN10200 w/simulator mn10200-*-*
7065 H8/500 simulator h8500-hitachi-hms or h8500hms
7066 HP/PA running BSD hppa*-*-bsd*
7067 HP/PA running OSF/1 hppa*-*-osf*
7068 HP/PA Pro target hppa*-*-pro*
7069 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
7070 386BSD i[3456]86-*-bsd*
7071 Sequent family i[3456]86-sequent-sysv4*
7072 i[3456]86-sequent-sysv*
7073 i[3456]86-sequent-bsd*
7074 SPARC running LynxOS sparc-*-lynxos*
7075 SPARC running SunOS 4 sparc-*-sunos4*
7076 Tsqware Sparclet sparclet-*-*
7077 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7079 *** Changes in GDB 6.0:
7083 Support for debugging the Objective-C programming language has been
7084 integrated into GDB.
7086 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
7088 DWARF 2's Call Frame Information makes available compiler generated
7089 information that more exactly describes the program's run-time stack.
7090 By using this information, GDB is able to provide more robust stack
7093 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
7094 have been updated to use a new backtrace mechanism which includes
7095 DWARF 2 CFI support.
7099 GDB's remote protocol has been extended to include support for hosted
7100 file I/O (where the remote target uses GDB's file system). See GDB's
7101 remote protocol documentation for details.
7103 * All targets using the new architecture framework.
7105 All of GDB's targets have been updated to use the new internal
7106 architecture framework. The way is now open for future GDB releases
7107 to include cross-architecture native debugging support (i386 on amd64,
7110 * GNU/Linux's Thread Local Storage (TLS)
7112 GDB now includes support for for the GNU/Linux implementation of
7113 per-thread variables.
7115 * GNU/Linux's Native POSIX Thread Library (NPTL)
7117 GDB's thread code has been updated to work with either the new
7118 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
7120 * Separate debug info.
7122 GDB, in conjunction with BINUTILS, now supports a mechanism for
7123 automatically loading debug information from a separate file. Instead
7124 of shipping full debug and non-debug versions of system libraries,
7125 system integrators can now instead ship just the stripped libraries
7126 and optional debug files.
7128 * DWARF 2 Location Expressions
7130 DWARF 2 Location Expressions allow the compiler to more completely
7131 describe the location of variables (even in optimized code) to the
7134 GDB now includes preliminary support for location expressions (support
7135 for DW_OP_piece is still missing).
7139 A number of long standing bugs that caused GDB to die while starting a
7140 Java application have been fixed. GDB's Java support is now
7141 considered "useable".
7143 * GNU/Linux support for fork, vfork, and exec.
7145 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
7146 commands are now implemented for GNU/Linux. They require a 2.5.x or later
7149 * GDB supports logging output to a file
7151 There are two new commands, "set logging" and "show logging", which can be
7152 used to capture GDB's output to a file.
7154 * The meaning of "detach" has changed for gdbserver
7156 The "detach" command will now resume the application, as documented. To
7157 disconnect from gdbserver and leave it stopped, use the new "disconnect"
7160 * d10v, m68hc11 `regs' command deprecated
7162 The `info registers' command has been updated so that it displays the
7163 registers using a format identical to the old `regs' command.
7167 A new command, "maint set profile on/off", has been added. This command can
7168 be used to enable or disable profiling while running GDB, to profile a
7169 session or a set of commands. In addition there is a new configure switch,
7170 "--enable-profiling", which will cause GDB to be compiled with profiling
7171 data, for more informative profiling results.
7173 * Default MI syntax changed to "mi2".
7175 The default MI (machine interface) syntax, enabled by the command line
7176 option "-i=mi", has been changed to "mi2". The previous MI syntax,
7177 "mi1", can be enabled by specifying the option "-i=mi1".
7179 Support for the original "mi0" syntax (included in GDB 5.0) has been
7182 Fix for gdb/192: removed extraneous space when displaying frame level.
7183 Fix for gdb/672: update changelist is now output in mi list format.
7184 Fix for gdb/702: a -var-assign that updates the value now shows up
7185 in a subsequent -var-update.
7187 * New native configurations.
7189 FreeBSD/amd64 x86_64-*-freebsd*
7191 * Multi-arched targets.
7193 HP/PA HPUX11 hppa*-*-hpux*
7194 Renesas M32R/D w/simulator m32r-*-elf*
7196 * OBSOLETE configurations and files
7198 Configurations that have been declared obsolete in this release have
7199 been commented out. Unless there is activity to revive these
7200 configurations, the next release of GDB will have their sources
7201 permanently REMOVED.
7203 Z8000 simulator z8k-zilog-none or z8ksim
7204 Matsushita MN10200 w/simulator mn10200-*-*
7205 H8/500 simulator h8500-hitachi-hms or h8500hms
7206 HP/PA running BSD hppa*-*-bsd*
7207 HP/PA running OSF/1 hppa*-*-osf*
7208 HP/PA Pro target hppa*-*-pro*
7209 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
7210 Sequent family i[3456]86-sequent-sysv4*
7211 i[3456]86-sequent-sysv*
7212 i[3456]86-sequent-bsd*
7213 Tsqware Sparclet sparclet-*-*
7214 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7216 * REMOVED configurations and files
7219 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7220 IBM AIX PS/2 i[3456]86-*-aix
7221 i386 running Mach 3.0 i[3456]86-*-mach3*
7222 i386 running Mach i[3456]86-*-mach*
7223 i386 running OSF/1 i[3456]86-*osf1mk*
7224 HP/Apollo 68k Family m68*-apollo*-sysv*,
7226 m68*-hp-bsd*, m68*-hp-hpux*
7227 Argonaut Risc Chip (ARC) arc-*-*
7228 Mitsubishi D30V d30v-*-*
7229 Fujitsu FR30 fr30-*-elf*
7230 OS/9000 i[34]86-*-os9k
7231 I960 with MON960 i960-*-coff
7233 * MIPS $fp behavior changed
7235 The convenience variable $fp, for the MIPS, now consistently returns
7236 the address of the current frame's base. Previously, depending on the
7237 context, $fp could refer to either $sp or the current frame's base
7238 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
7239 The GNU Source-Level Debugger''.
7241 *** Changes in GDB 5.3:
7243 * GNU/Linux shared library multi-threaded performance improved.
7245 When debugging a multi-threaded application on GNU/Linux, GDB now uses
7246 `/proc', in preference to `ptrace' for memory reads. This may result
7247 in an improvement in the start-up time of multi-threaded, shared
7248 library applications when run under GDB. One GDB user writes: ``loads
7249 shared libs like mad''.
7251 * ``gdbserver'' now supports multi-threaded applications on some targets
7253 Support for debugging multi-threaded applications which use
7254 the GNU/Linux LinuxThreads package has been added for
7255 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
7256 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
7258 * GDB now supports C/C++ preprocessor macros.
7260 GDB now expands preprocessor macro invocations in C/C++ expressions,
7261 and provides various commands for showing macro definitions and how
7264 The new command `macro expand EXPRESSION' expands any macro
7265 invocations in expression, and shows the result.
7267 The new command `show macro MACRO-NAME' shows the definition of the
7268 macro named MACRO-NAME, and where it was defined.
7270 Most compilers don't include information about macros in the debugging
7271 information by default. In GCC 3.1, for example, you need to compile
7272 your program with the options `-gdwarf-2 -g3'. If the macro
7273 information is present in the executable, GDB will read it.
7275 * Multi-arched targets.
7277 DEC Alpha (partial) alpha*-*-*
7278 DEC VAX (partial) vax-*-*
7280 National Semiconductor NS32000 (partial) ns32k-*-*
7281 Motorola 68000 (partial) m68k-*-*
7282 Motorola MCORE mcore-*-*
7286 Fujitsu FRV architecture added by Red Hat frv*-*-*
7289 * New native configurations
7291 Alpha NetBSD alpha*-*-netbsd*
7292 SH NetBSD sh*-*-netbsdelf*
7293 MIPS NetBSD mips*-*-netbsd*
7294 UltraSPARC NetBSD sparc64-*-netbsd*
7296 * OBSOLETE configurations and files
7298 Configurations that have been declared obsolete in this release have
7299 been commented out. Unless there is activity to revive these
7300 configurations, the next release of GDB will have their sources
7301 permanently REMOVED.
7303 Mitsubishi D30V d30v-*-*
7304 OS/9000 i[34]86-*-os9k
7305 IBM AIX PS/2 i[3456]86-*-aix
7306 Fujitsu FR30 fr30-*-elf*
7307 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7308 Argonaut Risc Chip (ARC) arc-*-*
7309 i386 running Mach 3.0 i[3456]86-*-mach3*
7310 i386 running Mach i[3456]86-*-mach*
7311 i386 running OSF/1 i[3456]86-*osf1mk*
7312 HP/Apollo 68k Family m68*-apollo*-sysv*,
7314 m68*-hp-bsd*, m68*-hp-hpux*
7315 I960 with MON960 i960-*-coff
7317 * OBSOLETE languages
7319 CHILL, a Pascal like language used by telecommunications companies.
7321 * REMOVED configurations and files
7323 AMD 29k family via UDI a29k-amd-udi, udi29k
7324 A29K VxWorks a29k-*-vxworks
7325 AMD 29000 embedded, using EBMON a29k-none-none
7326 AMD 29000 embedded with COFF a29k-none-coff
7327 AMD 29000 embedded with a.out a29k-none-aout
7329 testsuite/gdb.hp/gdb.threads-hp/ directory
7331 * New command "set max-user-call-depth <nnn>"
7333 This command allows the user to limit the call depth of user-defined
7334 commands. The default is 1024.
7336 * Changes in FreeBSD/i386 native debugging.
7338 Support for the "generate-core-file" has been added.
7340 * New commands "dump", "append", and "restore".
7342 These commands allow data to be copied from target memory
7343 to a bfd-format or binary file (dump and append), and back
7344 from a file into memory (restore).
7346 * Improved "next/step" support on multi-processor Alpha Tru64.
7348 The previous single-step mechanism could cause unpredictable problems,
7349 including the random appearance of SIGSEGV or SIGTRAP signals. The use
7350 of a software single-step mechanism prevents this.
7352 *** Changes in GDB 5.2.1:
7360 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
7361 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
7362 Fix, by Joel Brobecker imported from mainline.
7364 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
7365 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
7366 Fix, by Fred Fish, imported from mainline.
7368 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
7369 Surprisingly enough, it works now.
7370 By Michal Ludvig, imported from mainline.
7372 i386 hardware watchpoint support:
7373 avoid misses on second run for some targets.
7374 By Pierre Muller, imported from mainline.
7376 *** Changes in GDB 5.2:
7378 * New command "set trust-readonly-sections on[off]".
7380 This command is a hint that tells gdb that read-only sections
7381 really are read-only (ie. that their contents will not change).
7382 In this mode, gdb will go to the object file rather than the
7383 target to read memory from read-only sections (such as ".text").
7384 This can be a significant performance improvement on some
7385 (notably embedded) targets.
7387 * New command "generate-core-file" (or "gcore").
7389 This new gdb command allows the user to drop a core file of the child
7390 process state at any time. So far it's been implemented only for
7391 GNU/Linux and Solaris, but should be relatively easily ported to other
7392 hosts. Argument is core file name (defaults to core.<pid>).
7394 * New command line option
7396 GDB now accepts --pid or -p followed by a process id.
7398 * Change in command line behavior -- corefiles vs. process ids.
7400 There is a subtle behavior in the way in which GDB handles
7401 command line arguments. The first non-flag argument is always
7402 a program to debug, but the second non-flag argument may either
7403 be a corefile or a process id. Previously, GDB would attempt to
7404 open the second argument as a corefile, and if that failed, would
7405 issue a superfluous error message and then attempt to attach it as
7406 a process. Now, if the second argument begins with a non-digit,
7407 it will be treated as a corefile. If it begins with a digit,
7408 GDB will attempt to attach it as a process, and if no such process
7409 is found, will then attempt to open it as a corefile.
7411 * Changes in ARM configurations.
7413 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
7414 configuration is fully multi-arch.
7416 * New native configurations
7418 ARM NetBSD arm*-*-netbsd*
7419 x86 OpenBSD i[3456]86-*-openbsd*
7420 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7421 Sparc64 running FreeBSD sparc64-*-freebsd*
7425 Sanyo XStormy16 xstormy16-elf
7427 * OBSOLETE configurations and files
7429 Configurations that have been declared obsolete in this release have
7430 been commented out. Unless there is activity to revive these
7431 configurations, the next release of GDB will have their sources
7432 permanently REMOVED.
7434 AMD 29k family via UDI a29k-amd-udi, udi29k
7435 A29K VxWorks a29k-*-vxworks
7436 AMD 29000 embedded, using EBMON a29k-none-none
7437 AMD 29000 embedded with COFF a29k-none-coff
7438 AMD 29000 embedded with a.out a29k-none-aout
7440 testsuite/gdb.hp/gdb.threads-hp/ directory
7442 * REMOVED configurations and files
7444 TI TMS320C80 tic80-*-*
7446 PowerPC Solaris powerpcle-*-solaris*
7447 PowerPC Windows NT powerpcle-*-cygwin32
7448 PowerPC Netware powerpc-*-netware*
7449 Harris/CXUX m88k m88*-harris-cxux*
7450 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7451 ns32k-utek-sysv* ns32k-utek-*
7452 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7453 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7454 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7455 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7456 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7458 * Changes to command line processing
7460 The new `--args' feature can be used to specify command-line arguments
7461 for the inferior from gdb's command line.
7463 * Changes to key bindings
7465 There is a new `operate-and-get-next' function bound to `C-o'.
7467 *** Changes in GDB 5.1.1
7469 Fix compile problem on DJGPP.
7471 Fix a problem with floating-point registers on the i386 being
7474 Fix to stop GDB crashing on .debug_str debug info.
7476 Numerous documentation fixes.
7478 Numerous testsuite fixes.
7480 *** Changes in GDB 5.1:
7482 * New native configurations
7484 Alpha FreeBSD alpha*-*-freebsd*
7485 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7486 MIPS GNU/Linux mips*-*-linux*
7487 MIPS SGI Irix 6.x mips*-sgi-irix6*
7488 ia64 AIX ia64-*-aix*
7489 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7493 Motorola 68HC11 and 68HC12 m68hc11-elf
7495 UltraSparc running GNU/Linux sparc64-*-linux*
7497 * OBSOLETE configurations and files
7499 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7500 Harris/CXUX m88k m88*-harris-cxux*
7501 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7502 ns32k-utek-sysv* ns32k-utek-*
7503 TI TMS320C80 tic80-*-*
7505 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7506 PowerPC Solaris powerpcle-*-solaris*
7507 PowerPC Windows NT powerpcle-*-cygwin32
7508 PowerPC Netware powerpc-*-netware*
7509 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7510 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7511 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7512 Apple Macintosh (MPW) host N/A
7514 stuff.c (Program to stuff files into a specially prepared space in kdb)
7515 kdb-start.c (Main loop for the standalone kernel debugger)
7517 Configurations that have been declared obsolete in this release have
7518 been commented out. Unless there is activity to revive these
7519 configurations, the next release of GDB will have their sources
7520 permanently REMOVED.
7522 * REMOVED configurations and files
7524 Altos 3068 m68*-altos-*
7525 Convex c1-*-*, c2-*-*
7527 ARM RISCix arm-*-* (as host)
7531 * GDB has been converted to ISO C.
7533 GDB's source code has been converted to ISO C. In particular, the
7534 sources are fully protoized, and rely on standard headers being
7539 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
7541 * The MI enabled by default.
7543 The new machine oriented interface (MI) introduced in GDB 5.0 has been
7544 revised and enabled by default. Packages which use GDB as a debugging
7545 engine behind a UI or another front end are encouraged to switch to
7546 using the GDB/MI interface, instead of the old annotations interface
7547 which is now deprecated.
7549 * Support for debugging Pascal programs.
7551 GDB now includes support for debugging Pascal programs. The following
7552 main features are supported:
7554 - Pascal-specific data types such as sets;
7556 - automatic recognition of Pascal sources based on file-name
7559 - Pascal-style display of data types, variables, and functions;
7561 - a Pascal expression parser.
7563 However, some important features are not yet supported.
7565 - Pascal string operations are not supported at all;
7567 - there are some problems with boolean types;
7569 - Pascal type hexadecimal constants are not supported
7570 because they conflict with the internal variables format;
7572 - support for Pascal objects and classes is not full yet;
7574 - unlike Pascal, GDB is case-sensitive for symbol names.
7576 * Changes in completion.
7578 Commands such as `shell', `run' and `set args', which pass arguments
7579 to inferior programs, now complete on file names, similar to what
7580 users expect at the shell prompt.
7582 Commands which accept locations, such as `disassemble', `print',
7583 `breakpoint', `until', etc. now complete on filenames as well as
7584 program symbols. Thus, if you type "break foob TAB", and the source
7585 files linked into the programs include `foobar.c', that file name will
7586 be one of the candidates for completion. However, file names are not
7587 considered for completion after you typed a colon that delimits a file
7588 name from a name of a function in that file, as in "break foo.c:bar".
7590 `set demangle-style' completes on available demangling styles.
7592 * New platform-independent commands:
7594 It is now possible to define a post-hook for a command as well as a
7595 hook that runs before the command. For more details, see the
7596 documentation of `hookpost' in the GDB manual.
7598 * Changes in GNU/Linux native debugging.
7600 Support for debugging multi-threaded programs has been completely
7601 revised for all platforms except m68k and sparc. You can now debug as
7602 many threads as your system allows you to have.
7604 Attach/detach is supported for multi-threaded programs.
7606 Support for SSE registers was added for x86. This doesn't work for
7607 multi-threaded programs though.
7609 * Changes in MIPS configurations.
7611 Multi-arch support is enabled for all MIPS configurations.
7613 GDB can now be built as native debugger on SGI Irix 6.x systems for
7614 debugging n32 executables. (Debugging 64-bit executables is not yet
7617 * Unified support for hardware watchpoints in all x86 configurations.
7619 Most (if not all) native x86 configurations support hardware-assisted
7620 breakpoints and watchpoints in a unified manner. This support
7621 implements debug register sharing between watchpoints, which allows to
7622 put a virtually infinite number of watchpoints on the same address,
7623 and also supports watching regions up to 16 bytes with several debug
7626 The new maintenance command `maintenance show-debug-regs' toggles
7627 debugging print-outs in functions that insert, remove, and test
7628 watchpoints and hardware breakpoints.
7630 * Changes in the DJGPP native configuration.
7632 New command ``info dos sysinfo'' displays assorted information about
7633 the CPU, OS, memory, and DPMI server.
7635 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
7636 display information about segment descriptors stored in GDT, LDT, and
7639 New commands ``info dos pde'' and ``info dos pte'' display entries
7640 from Page Directory and Page Tables (for now works with CWSDPMI only).
7641 New command ``info dos address-pte'' displays the Page Table entry for
7642 a given linear address.
7644 GDB can now pass command lines longer than 126 characters to the
7645 program being debugged (requires an update to the libdbg.a library
7646 which is part of the DJGPP development kit).
7648 DWARF2 debug info is now supported.
7650 It is now possible to `step' and `next' through calls to `longjmp'.
7652 * Changes in documentation.
7654 All GDB documentation was converted to GFDL, the GNU Free
7655 Documentation License.
7657 Tracepoints-related commands are now fully documented in the GDB
7660 TUI, the Text-mode User Interface, is now documented in the manual.
7662 Tracepoints-related commands are now fully documented in the GDB
7665 The "GDB Internals" manual now has an index. It also includes
7666 documentation of `ui_out' functions, GDB coding standards, x86
7667 hardware watchpoints, and memory region attributes.
7669 * GDB's version number moved to ``version.in''
7671 The Makefile variable VERSION has been replaced by the file
7672 ``version.in''. People creating GDB distributions should update the
7673 contents of this file.
7677 GUD support is now a standard part of the EMACS distribution.
7679 *** Changes in GDB 5.0:
7681 * Improved support for debugging FP programs on x86 targets
7683 Unified and much-improved support for debugging floating-point
7684 programs on all x86 targets. In particular, ``info float'' now
7685 displays the FP registers in the same format on all x86 targets, with
7686 greater level of detail.
7688 * Improvements and bugfixes in hardware-assisted watchpoints
7690 It is now possible to watch array elements, struct members, and
7691 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7692 on x86 targets no longer erroneously trigger when the address is
7695 * Improvements in the native DJGPP version of GDB
7697 The distribution now includes all the scripts and auxiliary files
7698 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7699 machines ``out of the box''.
7701 The DJGPP version can now debug programs that use signals. It is
7702 possible to catch signals that happened in the debuggee, deliver
7703 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7704 would kill the program being debugged.) Programs that hook hardware
7705 interrupts (keyboard, timer, etc.) can also be debugged.
7707 It is now possible to debug DJGPP programs that redirect their
7708 standard handles or switch them to raw (as opposed to cooked) mode, or
7709 even close them. The command ``run < foo > bar'' works as expected,
7710 and ``info terminal'' reports useful information about the debuggee's
7711 terminal, including raw/cooked mode, redirection, etc.
7713 The DJGPP version now uses termios functions for console I/O, which
7714 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7717 DOS-style file names with drive letters are now fully supported by
7720 It is now possible to debug DJGPP programs that switch their working
7721 directory. It is also possible to rerun the debuggee any number of
7722 times without restarting GDB; thus, you can use the same setup,
7723 breakpoints, etc. for many debugging sessions.
7725 * New native configurations
7727 ARM GNU/Linux arm*-*-linux*
7728 PowerPC GNU/Linux powerpc-*-linux*
7732 Motorola MCore mcore-*-*
7733 x86 VxWorks i[3456]86-*-vxworks*
7734 PowerPC VxWorks powerpc-*-vxworks*
7735 TI TMS320C80 tic80-*-*
7737 * OBSOLETE configurations
7739 Altos 3068 m68*-altos-*
7740 Convex c1-*-*, c2-*-*
7742 ARM RISCix arm-*-* (as host)
7745 Configurations that have been declared obsolete will be commented out,
7746 but the code will be left in place. If there is no activity to revive
7747 these configurations before the next release of GDB, the sources will
7748 be permanently REMOVED.
7750 * Gould support removed
7752 Support for the Gould PowerNode and NP1 has been removed.
7754 * New features for SVR4
7756 On SVR4 native platforms (such as Solaris), if you attach to a process
7757 without first loading a symbol file, GDB will now attempt to locate and
7758 load symbols from the running process's executable file.
7760 * Many C++ enhancements
7762 C++ support has been greatly improved. Overload resolution now works properly
7763 in almost all cases. RTTI support is on the way.
7765 * Remote targets can connect to a sub-program
7767 A popen(3) style serial-device has been added. This device starts a
7768 sub-process (such as a stand-alone simulator) and then communicates
7769 with that. The sub-program to run is specified using the syntax
7770 ``|<program> <args>'' vis:
7772 (gdb) set remotedebug 1
7773 (gdb) target extended-remote |mn10300-elf-sim program-args
7775 * MIPS 64 remote protocol
7777 A long standing bug in the mips64 remote protocol where by GDB
7778 expected certain 32 bit registers (ex SR) to be transfered as 32
7779 instead of 64 bits has been fixed.
7781 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7782 added to provide backward compatibility with older versions of GDB.
7784 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7786 The command ``set remotebinarydownload'' command has been replaced by
7787 ``set remote X-packet''. Other commands in ``set remote'' family
7788 include ``set remote P-packet''.
7790 * Breakpoint commands accept ranges.
7792 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7793 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7794 ``tracepoint passcount'' also accepts a range of tracepoints.
7796 * ``apropos'' command added.
7798 The ``apropos'' command searches through command names and
7799 documentation strings, printing out matches, making it much easier to
7800 try to find a command that does what you are looking for.
7804 A new machine oriented interface (MI) has been added to GDB. This
7805 interface is designed for debug environments running GDB as a separate
7806 process. This is part of the long term libGDB project. See the
7807 "GDB/MI" chapter of the GDB manual for further information. It can be
7808 enabled by configuring with:
7810 .../configure --enable-gdbmi
7812 *** Changes in GDB-4.18:
7814 * New native configurations
7816 HP-UX 10.20 hppa*-*-hpux10.20
7817 HP-UX 11.x hppa*-*-hpux11.0*
7818 M68K GNU/Linux m68*-*-linux*
7822 Fujitsu FR30 fr30-*-elf*
7823 Intel StrongARM strongarm-*-*
7824 Mitsubishi D30V d30v-*-*
7826 * OBSOLETE configurations
7828 Gould PowerNode, NP1 np1-*-*, pn-*-*
7830 Configurations that have been declared obsolete will be commented out,
7831 but the code will be left in place. If there is no activity to revive
7832 these configurations before the next release of GDB, the sources will
7833 be permanently REMOVED.
7837 As a compatibility experiment, GDB's source files buildsym.h and
7838 buildsym.c have been converted to pure standard C, no longer
7839 containing any K&R compatibility code. We believe that all systems in
7840 use today either come with a standard C compiler, or have a GCC port
7841 available. If this is not true, please report the affected
7842 configuration to bug-gdb@gnu.org immediately. See the README file for
7843 information about getting a standard C compiler if you don't have one
7848 GDB now uses readline 2.2.
7850 * set extension-language
7852 You can now control the mapping between filename extensions and source
7853 languages by using the `set extension-language' command. For instance,
7854 you can ask GDB to treat .c files as C++ by saying
7855 set extension-language .c c++
7856 The command `info extensions' lists all of the recognized extensions
7857 and their associated languages.
7859 * Setting processor type for PowerPC and RS/6000
7861 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7862 you can use the `set processor' command to specify what variant of the
7863 PowerPC family you are debugging. The command
7867 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7868 following PowerPC and RS6000 variants:
7870 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7871 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7873 403GC IBM PowerPC 403GC
7874 505 Motorola PowerPC 505
7875 860 Motorola PowerPC 860 or 850
7876 601 Motorola PowerPC 601
7877 602 Motorola PowerPC 602
7878 603 Motorola/IBM PowerPC 603 or 603e
7879 604 Motorola PowerPC 604 or 604e
7880 750 Motorola/IBM PowerPC 750 or 750
7882 At the moment, this command just tells GDB what to name the
7883 special-purpose processor registers. Since almost all the affected
7884 registers are inaccessible to user-level programs, this command is
7885 only useful for remote debugging in its present form.
7889 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7890 more extensive support for HP-UX. Added features include shared
7891 library support, kernel threads and hardware watchpoints for 11.00,
7892 support for HP's ANSI C and C++ compilers, and a compatibility mode
7893 for xdb and dbx commands.
7897 HP's donation includes the new concept of catchpoints, which is a
7898 generalization of the old catch command. On HP-UX, it is now possible
7899 to catch exec, fork, and vfork, as well as library loading.
7901 This means that the existing catch command has changed; its first
7902 argument now specifies the type of catch to be set up. See the
7903 output of "help catch" for a list of catchpoint types.
7905 * Debugging across forks
7907 On HP-UX, you can choose which process to debug when a fork() happens
7912 HP has donated a curses-based terminal user interface (TUI). To get
7913 it, build with --enable-tui. Although this can be enabled for any
7914 configuration, at present it only works for native HP debugging.
7916 * GDB remote protocol additions
7918 A new protocol packet 'X' that writes binary data is now available.
7919 Default behavior is to try 'X', then drop back to 'M' if the stub
7920 fails to respond. The settable variable `remotebinarydownload'
7921 allows explicit control over the use of 'X'.
7923 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7924 full 64-bit address. The command
7926 set remoteaddresssize 32
7928 can be used to revert to the old behaviour. For existing remote stubs
7929 the change should not be noticed, as the additional address information
7932 In order to assist in debugging stubs, you may use the maintenance
7933 command `packet' to send any text string to the stub. For instance,
7935 maint packet heythere
7937 sends the packet "$heythere#<checksum>". Note that it is very easy to
7938 disrupt a debugging session by sending the wrong packet at the wrong
7941 The compare-sections command allows you to compare section data on the
7942 target to what is in the executable file without uploading or
7943 downloading, by comparing CRC checksums.
7945 * Tracing can collect general expressions
7947 You may now collect general expressions at tracepoints. This requires
7948 further additions to the target-side stub; see tracepoint.c and
7949 doc/agentexpr.texi for further details.
7951 * mask-address variable for Mips
7953 For Mips targets, you may control the zeroing of the upper 32 bits of
7954 a 64-bit address by entering `set mask-address on'. This is mainly
7955 of interest to users of embedded R4xxx and R5xxx processors.
7957 * Higher serial baud rates
7959 GDB's serial code now allows you to specify baud rates 57600, 115200,
7960 230400, and 460800 baud. (Note that your host system may not be able
7961 to achieve all of these rates.)
7965 The i960 configuration now includes an initial implementation of a
7966 builtin simulator, contributed by Jim Wilson.
7969 *** Changes in GDB-4.17:
7971 * New native configurations
7973 Alpha GNU/Linux alpha*-*-linux*
7974 Unixware 2.x i[3456]86-unixware2*
7975 Irix 6.x mips*-sgi-irix6*
7976 PowerPC GNU/Linux powerpc-*-linux*
7977 PowerPC Solaris powerpcle-*-solaris*
7978 Sparc GNU/Linux sparc-*-linux*
7979 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7983 Argonaut Risc Chip (ARC) arc-*-*
7984 Hitachi H8/300S h8300*-*-*
7985 Matsushita MN10200 w/simulator mn10200-*-*
7986 Matsushita MN10300 w/simulator mn10300-*-*
7987 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7988 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7989 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7990 Mitsubishi D10V w/simulator d10v-*-*
7991 Mitsubishi M32R/D w/simulator m32r-*-elf*
7992 Tsqware Sparclet sparclet-*-*
7993 NEC V850 w/simulator v850-*-*
7995 * New debugging protocols
7997 ARM with RDI protocol arm*-*-*
7998 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7999 DDB and LSI variants of PMON protocol mips*-*-*
8000 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
8001 PowerPC with SDS protocol powerpc{,le}-*-eabi
8002 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
8006 All configurations can now understand and use the DWARF 2 debugging
8007 format. The choice is automatic, if the symbol file contains DWARF 2
8012 GDB now includes basic Java language support. This support is
8013 only useful with Java compilers that produce native machine code.
8015 * solib-absolute-prefix and solib-search-path
8017 For SunOS and SVR4 shared libraries, you may now set the prefix for
8018 loading absolute shared library symbol files, and the search path for
8019 locating non-absolute shared library symbol files.
8021 * Live range splitting
8023 GDB can now effectively debug code for which GCC has performed live
8024 range splitting as part of its optimization. See gdb/doc/LRS for
8025 more details on the expected format of the stabs information.
8029 GDB's support for the GNU Hurd, including thread debugging, has been
8030 updated to work with current versions of the Hurd.
8034 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
8035 instruction set. ARM GDB automatically detects when Thumb
8036 instructions are in use, and adjusts disassembly and backtracing
8041 GDB's MIPS target configurations now handle the MIP16 16-bit
8046 GDB now includes support for overlays; if an executable has been
8047 linked such that multiple sections are based at the same address, GDB
8048 will decide which section to use for symbolic info. You can choose to
8049 control the decision manually, using overlay commands, or implement
8050 additional target-side support and use "overlay load-target" to bring
8051 in the overlay mapping. Do "help overlay" for more detail.
8055 The command "info symbol <address>" displays information about
8056 the symbol at the specified address.
8060 The standard remote protocol now includes an extension that allows
8061 asynchronous collection and display of trace data. This requires
8062 extensive support in the target-side debugging stub. Tracing mode
8063 includes a new interaction mode in GDB and new commands: see the
8064 file tracepoint.c for more details.
8068 Configurations for embedded MIPS now include a simulator contributed
8069 by Cygnus Solutions. The simulator supports the instruction sets
8070 of most MIPS variants.
8074 Sparc configurations may now include the ERC32 simulator contributed
8075 by the European Space Agency. The simulator is not built into
8076 Sparc targets by default; configure with --enable-sim to include it.
8080 For target configurations that may include multiple variants of a
8081 basic architecture (such as MIPS and SH), you may now set the
8082 architecture explicitly. "set arch" sets, "info arch" lists
8083 the possible architectures.
8085 *** Changes in GDB-4.16:
8087 * New native configurations
8089 Windows 95, x86 Windows NT i[345]86-*-cygwin32
8090 M68K NetBSD m68k-*-netbsd*
8091 PowerPC AIX 4.x powerpc-*-aix*
8092 PowerPC MacOS powerpc-*-macos*
8093 PowerPC Windows NT powerpcle-*-cygwin32
8094 RS/6000 AIX 4.x rs6000-*-aix4*
8098 ARM with RDP protocol arm-*-*
8099 I960 with MON960 i960-*-coff
8100 MIPS VxWorks mips*-*-vxworks*
8101 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
8102 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
8104 Matra Sparclet sparclet-*-*
8108 The powerpc-eabi configuration now includes the PSIM simulator,
8109 contributed by Andrew Cagney, with assistance from Mike Meissner.
8110 PSIM is a very elaborate model of the PowerPC, including not only
8111 basic instruction set execution, but also details of execution unit
8112 performance and I/O hardware. See sim/ppc/README for more details.
8116 GDB now works with Solaris 2.5.
8118 * Windows 95/NT native
8120 GDB will now work as a native debugger on Windows 95 and Windows NT.
8121 To build it from source, you must use the "gnu-win32" environment,
8122 which uses a DLL to emulate enough of Unix to run the GNU tools.
8123 Further information, binaries, and sources are available at
8124 ftp.cygnus.com, under pub/gnu-win32.
8126 * dont-repeat command
8128 If a user-defined command includes the command `dont-repeat', then the
8129 command will not be repeated if the user just types return. This is
8130 useful if the command is time-consuming to run, so that accidental
8131 extra keystrokes don't run the same command many times.
8133 * Send break instead of ^C
8135 The standard remote protocol now includes an option to send a break
8136 rather than a ^C to the target in order to interrupt it. By default,
8137 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
8139 * Remote protocol timeout
8141 The standard remote protocol includes a new variable `remotetimeout'
8142 that allows you to set the number of seconds before GDB gives up trying
8143 to read from the target. The default value is 2.
8145 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
8147 By default GDB will automatically keep track of objects as they are
8148 loaded and unloaded by the dynamic linker. By using the command `set
8149 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
8150 when shared library events occur, thus allowing you to set breakpoints
8151 in shared libraries which are explicitly loaded by the inferior.
8153 Note this feature does not work on hpux8. On hpux9 you must link
8154 /usr/lib/end.o into your program. This feature should work
8155 automatically on hpux10.
8157 * Irix 5.x hardware watchpoint support
8159 Irix 5 configurations now support the use of hardware watchpoints.
8161 * Mips protocol "SYN garbage limit"
8163 When debugging a Mips target using the `target mips' protocol, you
8164 may set the number of characters that GDB will ignore by setting
8165 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
8166 every character. The default value is 1050.
8168 * Recording and replaying remote debug sessions
8170 If you set `remotelogfile' to the name of a file, gdb will write to it
8171 a recording of a remote debug session. This recording may then be
8172 replayed back to gdb using "gdbreplay". See gdbserver/README for
8173 details. This is useful when you have a problem with GDB while doing
8174 remote debugging; you can make a recording of the session and send it
8175 to someone else, who can then recreate the problem.
8177 * Speedups for remote debugging
8179 GDB includes speedups for downloading and stepping MIPS systems using
8180 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
8181 and more efficient S-record downloading.
8183 * Memory use reductions and statistics collection
8185 GDB now uses less memory and reports statistics about memory usage.
8186 Try the `maint print statistics' command, for example.
8188 *** Changes in GDB-4.15:
8190 * Psymtabs for XCOFF
8192 The symbol reader for AIX GDB now uses partial symbol tables. This
8193 can greatly improve startup time, especially for large executables.
8195 * Remote targets use caching
8197 Remote targets now use a data cache to speed up communication with the
8198 remote side. The data cache could lead to incorrect results because
8199 it doesn't know about volatile variables, thus making it impossible to
8200 debug targets which use memory mapped I/O devices. `set remotecache
8201 off' turns the data cache off.
8203 * Remote targets may have threads
8205 The standard remote protocol now includes support for multiple threads
8206 in the target system, using new protocol commands 'H' and 'T'. See
8207 gdb/remote.c for details.
8211 If GDB is configured with `--enable-netrom', then it will include
8212 support for the NetROM ROM emulator from XLNT Designs. The NetROM
8213 acts as though it is a bank of ROM on the target board, but you can
8214 write into it over the network. GDB's support consists only of
8215 support for fast loading into the emulated ROM; to debug, you must use
8216 another protocol, such as standard remote protocol. The usual
8217 sequence is something like
8219 target nrom <netrom-hostname>
8221 target remote <netrom-hostname>:1235
8225 GDB now includes support for the Apple Macintosh, as a host only. It
8226 may be run as either an MPW tool or as a standalone application, and
8227 it can debug through the serial port. All the usual GDB commands are
8228 available, but to the target command, you must supply "serial" as the
8229 device type instead of "/dev/ttyXX". See mpw-README in the main
8230 directory for more information on how to build. The MPW configuration
8231 scripts */mpw-config.in support only a few targets, and only the
8232 mips-idt-ecoff target has been tested.
8236 GDB configuration now uses autoconf. This is not user-visible,
8237 but does simplify configuration and building.
8241 GDB now supports hpux10.
8243 *** Changes in GDB-4.14:
8245 * New native configurations
8247 x86 FreeBSD i[345]86-*-freebsd
8248 x86 NetBSD i[345]86-*-netbsd
8249 NS32k NetBSD ns32k-*-netbsd
8250 Sparc NetBSD sparc-*-netbsd
8254 A29K VxWorks a29k-*-vxworks
8255 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
8256 CPU32 EST-300 emulator m68*-*-est*
8257 PowerPC ELF powerpc-*-elf
8260 * Alpha OSF/1 support for procfs
8262 GDB now supports procfs under OSF/1-2.x and higher, which makes it
8263 possible to attach to running processes. As the mounting of the /proc
8264 filesystem is optional on the Alpha, GDB automatically determines
8265 the availability of /proc during startup. This can lead to problems
8266 if /proc is unmounted after GDB has been started.
8268 * Arguments to user-defined commands
8270 User commands may accept up to 10 arguments separated by whitespace.
8271 Arguments are accessed within the user command via $arg0..$arg9. A
8274 print $arg0 + $arg1 + $arg2
8276 To execute the command use:
8279 Defines the command "adder" which prints the sum of its three arguments.
8280 Note the arguments are text substitutions, so they may reference variables,
8281 use complex expressions, or even perform inferior function calls.
8283 * New `if' and `while' commands
8285 This makes it possible to write more sophisticated user-defined
8286 commands. Both commands take a single argument, which is the
8287 expression to evaluate, and must be followed by the commands to
8288 execute, one per line, if the expression is nonzero, the list being
8289 terminated by the word `end'. The `if' command list may include an
8290 `else' word, which causes the following commands to be executed only
8291 if the expression is zero.
8293 * Fortran source language mode
8295 GDB now includes partial support for Fortran 77. It will recognize
8296 Fortran programs and can evaluate a subset of Fortran expressions, but
8297 variables and functions may not be handled correctly. GDB will work
8298 with G77, but does not yet know much about symbols emitted by other
8301 * Better HPUX support
8303 Most debugging facilities now work on dynamic executables for HPPAs
8304 running hpux9 or later. You can attach to running dynamically linked
8305 processes, but by default the dynamic libraries will be read-only, so
8306 for instance you won't be able to put breakpoints in them. To change
8307 that behavior do the following before running the program:
8313 This will cause the libraries to be mapped private and read-write.
8314 To revert to the normal behavior, do this:
8320 You cannot set breakpoints or examine data in the library until after
8321 the library is loaded if the function/data symbols do not have
8324 GDB can now also read debug symbols produced by the HP C compiler on
8325 HPPAs (sorry, no C++, Fortran or 68k support).
8327 * Target byte order now dynamically selectable
8329 You can choose which byte order to use with a target system, via the
8330 commands "set endian big" and "set endian little", and you can see the
8331 current setting by using "show endian". You can also give the command
8332 "set endian auto", in which case GDB will use the byte order
8333 associated with the executable. Currently, only embedded MIPS
8334 configurations support dynamic selection of target byte order.
8336 * New DOS host serial code
8338 This version uses DPMI interrupts to handle buffered I/O, so you
8339 no longer need to run asynctsr when debugging boards connected to
8342 *** Changes in GDB-4.13:
8344 * New "complete" command
8346 This lists all the possible completions for the rest of the line, if it
8347 were to be given as a command itself. This is intended for use by emacs.
8349 * Trailing space optional in prompt
8351 "set prompt" no longer adds a space for you after the prompt you set. This
8352 allows you to set a prompt which ends in a space or one that does not.
8354 * Breakpoint hit counts
8356 "info break" now displays a count of the number of times the breakpoint
8357 has been hit. This is especially useful in conjunction with "ignore"; you
8358 can ignore a large number of breakpoint hits, look at the breakpoint info
8359 to see how many times the breakpoint was hit, then run again, ignoring one
8360 less than that number, and this will get you quickly to the last hit of
8363 * Ability to stop printing at NULL character
8365 "set print null-stop" will cause GDB to stop printing the characters of
8366 an array when the first NULL is encountered. This is useful when large
8367 arrays actually contain only short strings.
8369 * Shared library breakpoints
8371 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
8372 breakpoints in shared libraries before the executable is run.
8374 * Hardware watchpoints
8376 There is a new hardware breakpoint for the watch command for sparclite
8377 targets. See gdb/sparclite/hw_breakpoint.note.
8379 Hardware watchpoints are also now supported under GNU/Linux.
8383 Annotations have been added. These are for use with graphical interfaces,
8384 and are still experimental. Currently only gdba.el uses these.
8386 * Improved Irix 5 support
8388 GDB now works properly with Irix 5.2.
8390 * Improved HPPA support
8392 GDB now works properly with the latest GCC and GAS.
8394 * New native configurations
8396 Sequent PTX4 i[34]86-sequent-ptx4
8397 HPPA running OSF/1 hppa*-*-osf*
8398 Atari TT running SVR4 m68*-*-sysv4*
8399 RS/6000 LynxOS rs6000-*-lynxos*
8403 OS/9000 i[34]86-*-os9k
8404 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
8407 * Hitachi SH7000 and E7000-PC ICE support
8409 There is now support for communicating with the Hitachi E7000-PC ICE.
8410 This is available automatically when GDB is configured for the SH.
8414 As usual, a variety of small fixes and improvements, both generic
8415 and configuration-specific. See the ChangeLog for more detail.
8417 *** Changes in GDB-4.12:
8419 * Irix 5 is now supported
8423 GDB-4.12 on the HPPA has a number of changes which make it unable
8424 to debug the output from the currently released versions of GCC and
8425 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8426 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8427 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8430 *** Changes in GDB-4.11:
8432 * User visible changes:
8436 The "set remotedebug" option is now consistent between the mips remote
8437 target, remote targets using the gdb-specific protocol, UDI (AMD's
8438 debug protocol for the 29k) and the 88k bug monitor. It is now an
8439 integer specifying a debug level (normally 0 or 1, but 2 means more
8440 debugging info for the mips target).
8442 * DEC Alpha native support
8444 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8445 debug info, but GDB works fairly well with the DEC compiler and should
8446 work with a future GCC release. See the README file for a few
8447 Alpha-specific notes.
8449 * Preliminary thread implementation
8451 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8453 * LynxOS native and target support for 386
8455 This release has been hosted on LynxOS 2.2, and also can be configured
8456 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8459 * Improvements in C++ mangling/demangling.
8461 This release has much better g++ debugging, specifically in name
8462 mangling/demangling, virtual function calls, print virtual table,
8463 call methods, ...etc.
8465 *** Changes in GDB-4.10:
8467 * User visible changes:
8469 Remote debugging using the GDB-specific (`target remote') protocol now
8470 supports the `load' command. This is only useful if you have some
8471 other way of getting the stub to the target system, and you can put it
8472 somewhere in memory where it won't get clobbered by the download.
8474 Filename completion now works.
8476 When run under emacs mode, the "info line" command now causes the
8477 arrow to point to the line specified. Also, "info line" prints
8478 addresses in symbolic form (as well as hex).
8480 All vxworks based targets now support a user settable option, called
8481 vxworks-timeout. This option represents the number of seconds gdb
8482 should wait for responses to rpc's. You might want to use this if
8483 your vxworks target is, perhaps, a slow software simulator or happens
8484 to be on the far side of a thin network line.
8488 This release contains support for using a DEC alpha as a GDB host for
8489 cross debugging. Native alpha debugging is not supported yet.
8492 *** Changes in GDB-4.9:
8496 This is the first GDB release which is accompanied by a matching testsuite.
8497 The testsuite requires installation of dejagnu, which should be available
8498 via ftp from most sites that carry GNU software.
8502 'Cfront' style demangling has had its name changed to 'ARM' style, to
8503 emphasize that it was written from the specifications in the C++ Annotated
8504 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8505 disclaimers, it still generated too much confusion with users attempting to
8506 use gdb with AT&T cfront.
8510 GDB now uses a standard remote interface to a simulator library.
8511 So far, the library contains simulators for the Zilog Z8001/2, the
8512 Hitachi H8/300, H8/500 and Super-H.
8514 * New targets supported
8516 H8/300 simulator h8300-hitachi-hms or h8300hms
8517 H8/500 simulator h8500-hitachi-hms or h8500hms
8518 SH simulator sh-hitachi-hms or sh
8519 Z8000 simulator z8k-zilog-none or z8ksim
8520 IDT MIPS board over serial line mips-idt-ecoff
8522 Cross-debugging to GO32 targets is supported. It requires a custom
8523 version of the i386-stub.c module which is integrated with the
8524 GO32 memory extender.
8526 * New remote protocols
8528 MIPS remote debugging protocol.
8530 * New source languages supported
8532 This version includes preliminary support for Chill, a Pascal like language
8533 used by telecommunications companies. Chill support is also being integrated
8534 into the GNU compiler, but we don't know when it will be publically available.
8537 *** Changes in GDB-4.8:
8539 * HP Precision Architecture supported
8541 GDB now supports HP PA-RISC machines running HPUX. A preliminary
8542 version of this support was available as a set of patches from the
8543 University of Utah. GDB does not support debugging of programs
8544 compiled with the HP compiler, because HP will not document their file
8545 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
8546 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
8548 Many problems in the preliminary version have been fixed.
8550 * Faster and better demangling
8552 We have improved template demangling and fixed numerous bugs in the GNU style
8553 demangler. It can now handle type modifiers such as `static' or `const'. Wide
8554 character types (wchar_t) are now supported. Demangling of each symbol is now
8555 only done once, and is cached when the symbol table for a file is read in.
8556 This results in a small increase in memory usage for C programs, a moderate
8557 increase in memory usage for C++ programs, and a fantastic speedup in
8560 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
8561 from the specifications in the Annotated Reference Manual, which AT&T's
8562 compiler does not actually implement.
8564 * G++ multiple inheritance compiler problem
8566 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
8567 inheritance lattices was reworked to properly discover ambiguities. We
8568 recently found an example which causes this new algorithm to fail in a
8569 very subtle way, producing bad debug information for those classes.
8570 The file 'gcc.patch' (in this directory) can be applied to gcc to
8571 circumvent the problem. A future GCC release will contain a complete
8574 The previous G++ debug info problem (mentioned below for the gdb-4.7
8575 release) is fixed in gcc version 2.3.2.
8577 * Improved configure script
8579 The `configure' script will now attempt to guess your system type if
8580 you don't supply a host system type. The old scheme of supplying a
8581 host system triplet is preferable over using this. All the magic is
8582 done in the new `config.guess' script. Examine it for details.
8584 We have also brought our configure script much more in line with the FSF's
8585 version. It now supports the --with-xxx options. In particular,
8586 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
8587 The resulting GDB will not be able to read arbitrary object file formats --
8588 only the format ``expected'' to be used on the configured target system.
8589 We hope to make this the default in a future release.
8591 * Documentation improvements
8593 There's new internal documentation on how to modify GDB, and how to
8594 produce clean changes to the code. We implore people to read it
8595 before submitting changes.
8597 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
8598 M4 macros. The new texinfo.tex is provided in this release. Pre-built
8599 `info' files are also provided. To build `info' files from scratch,
8600 you will need the latest `makeinfo' release, which will be available in
8601 a future texinfo-X.Y release.
8603 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
8604 We're not sure exactly which versions have this problem, but it has
8605 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
8606 or better. If that isn't possible, there is a patch in
8607 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
8608 around this problem.
8612 GDB now supports array constants that can be used in expressions typed in by
8613 the user. The syntax is `{element, element, ...}'. Ie: you can now type
8614 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
8617 The new directory `gdb/sparclite' contains a program that demonstrates
8618 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
8620 * New native hosts supported
8622 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
8623 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
8625 * New targets supported
8627 AMD 29k family via UDI a29k-amd-udi or udi29k
8629 * New file formats supported
8631 BFD now supports reading HP/PA-RISC executables (SOM file format?),
8632 HPUX core files, and SCO 3.2v2 core files.
8636 Attaching to processes now works again; thanks for the many bug reports.
8638 We have also stomped on a bunch of core dumps caused by
8639 printf_filtered("%s") problems.
8641 We eliminated a copyright problem on the rpc and ptrace header files
8642 for VxWorks, which was discovered at the last minute during the 4.7
8643 release. You should now be able to build a VxWorks GDB.
8645 You can now interrupt gdb while an attached process is running. This
8646 will cause the attached process to stop, and give control back to GDB.
8648 We fixed problems caused by using too many file descriptors
8649 for reading symbols from object files and libraries. This was
8650 especially a problem for programs that used many (~100) shared
8653 The `step' command now only enters a subroutine if there is line number
8654 information for the subroutine. Otherwise it acts like the `next'
8655 command. Previously, `step' would enter subroutines if there was
8656 any debugging information about the routine. This avoids problems
8657 when using `cc -g1' on MIPS machines.
8659 * Internal improvements
8661 GDB's internal interfaces have been improved to make it easier to support
8662 debugging of multiple languages in the future.
8664 GDB now uses a common structure for symbol information internally.
8665 Minimal symbols (derived from linkage symbols in object files), partial
8666 symbols (from a quick scan of debug information), and full symbols
8667 contain a common subset of information, making it easier to write
8668 shared code that handles any of them.
8670 * New command line options
8672 We now accept --silent as an alias for --quiet.
8676 The memory-mapped-malloc library is now licensed under the GNU Library
8677 General Public License.
8679 *** Changes in GDB-4.7:
8681 * Host/native/target split
8683 GDB has had some major internal surgery to untangle the support for
8684 hosts and remote targets. Now, when you configure GDB for a remote
8685 target, it will no longer load in all of the support for debugging
8686 local programs on the host. When fully completed and tested, this will
8687 ensure that arbitrary host/target combinations are possible.
8689 The primary conceptual shift is to separate the non-portable code in
8690 GDB into three categories. Host specific code is required any time GDB
8691 is compiled on that host, regardless of the target. Target specific
8692 code relates to the peculiarities of the target, but can be compiled on
8693 any host. Native specific code is everything else: it can only be
8694 built when the host and target are the same system. Child process
8695 handling and core file support are two common `native' examples.
8697 GDB's use of /proc for controlling Unix child processes is now cleaner.
8698 It has been split out into a single module under the `target_ops' vector,
8699 plus two native-dependent functions for each system that uses /proc.
8701 * New hosts supported
8703 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8704 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8705 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8707 * New targets supported
8709 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8710 68030 and CPU32 m68030-*-*, m68332-*-*
8712 * New native hosts supported
8714 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8715 (386bsd is not well tested yet)
8716 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8718 * New file formats supported
8720 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8721 supports reading of `a.out.adobe' object files, which are an a.out
8722 format extended with minimal information about multiple sections.
8726 `show copying' is the same as the old `info copying'.
8727 `show warranty' is the same as `info warrantee'.
8728 These were renamed for consistency. The old commands continue to work.
8730 `info handle' is a new alias for `info signals'.
8732 You can now define pre-command hooks, which attach arbitrary command
8733 scripts to any command. The commands in the hook will be executed
8734 prior to the user's command. You can also create a hook which will be
8735 executed whenever the program stops. See gdb.texinfo.
8739 We now deal with Cfront style name mangling, and can even extract type
8740 info from mangled symbols. GDB can automatically figure out which
8741 symbol mangling style your C++ compiler uses.
8743 Calling of methods and virtual functions has been improved as well.
8747 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8748 fixed. This was due to mishandling of the extra N_SO stabs output
8751 We also finally got Ultrix 4.2 running in house, and fixed core file
8752 support, with help from a dozen people on the net.
8754 John M. Farrell discovered that the reason that single-stepping was so
8755 slow on all of the Mips based platforms (primarily SGI and DEC) was
8756 that we were trying to demangle and lookup a symbol used for internal
8757 purposes on every instruction that was being stepped through. Changing
8758 the name of that symbol so that it couldn't be mistaken for a C++
8759 mangled symbol sped things up a great deal.
8761 Rich Pixley sped up symbol lookups in general by getting much smarter
8762 about when C++ symbol mangling is necessary. This should make symbol
8763 completion (TAB on the command line) much faster. It's not as fast as
8764 we'd like, but it's significantly faster than gdb-4.6.
8768 A new user controllable variable 'call_scratch_address' can
8769 specify the location of a scratch area to be used when GDB
8770 calls a function in the target. This is necessary because the
8771 usual method of putting the scratch area on the stack does not work
8772 in systems that have separate instruction and data spaces.
8774 We integrated changes to support the 29k UDI (Universal Debugger
8775 Interface), but discovered at the last minute that we didn't have all
8776 of the appropriate copyright paperwork. We are working with AMD to
8777 resolve this, and hope to have it available soon.
8781 We have sped up the remote serial line protocol, especially for targets
8782 with lots of registers. It now supports a new `expedited status' ('T')
8783 message which can be used in place of the existing 'S' status message.
8784 This allows the remote stub to send only the registers that GDB
8785 needs to make a quick decision about single-stepping or conditional
8786 breakpoints, eliminating the need to fetch the entire register set for
8787 each instruction being stepped through.
8789 The GDB remote serial protocol now implements a write-through cache for
8790 registers, only re-reading the registers if the target has run.
8792 There is also a new remote serial stub for SPARC processors. You can
8793 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8794 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8795 processor with a serial port.
8799 Configure.in files have become much easier to read and modify. A new
8800 `table driven' format makes it more obvious what configurations are
8801 supported, and what files each one uses.
8805 There is a new opcodes library which will eventually contain all of the
8806 disassembly routines and opcode tables. At present, it only contains
8807 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8808 disassembler (binutils/objdump) to share these routines.
8810 The libiberty library is now copylefted under the GNU Library General
8811 Public License. This allows more liberal use, and was done so libg++
8812 can use it. This makes no difference to GDB, since the Library License
8813 grants all the rights from the General Public License.
8817 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8818 reference to the stabs symbol info used by the debugger. It is (as far
8819 as we know) the only published document on this fascinating topic. We
8820 encourage you to read it, compare it to the stabs information on your
8821 system, and send improvements on the document in general (to
8822 bug-gdb@prep.ai.mit.edu).
8824 And, of course, many bugs have been fixed.
8827 *** Changes in GDB-4.6:
8829 * Better support for C++ function names
8831 GDB now accepts as input the "demangled form" of C++ overloaded function
8832 names and member function names, and can do command completion on such names
8833 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8834 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8835 Make use of command completion, it is your friend.
8837 GDB also now accepts a variety of C++ mangled symbol formats. They are
8838 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8839 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8840 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8841 for the list of formats.
8843 * G++ symbol mangling problem
8845 Recent versions of gcc have a bug in how they emit debugging information for
8846 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8847 directory) can be applied to gcc to fix the problem. Alternatively, if you
8848 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8849 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8850 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8853 * New 'maintenance' command
8855 All of the commands related to hacking GDB internals have been moved out of
8856 the main command set, and now live behind the 'maintenance' command. This
8857 can also be abbreviated as 'mt'. The following changes were made:
8859 dump-me -> maintenance dump-me
8860 info all-breakpoints -> maintenance info breakpoints
8861 printmsyms -> maintenance print msyms
8862 printobjfiles -> maintenance print objfiles
8863 printpsyms -> maintenance print psymbols
8864 printsyms -> maintenance print symbols
8866 The following commands are new:
8868 maintenance demangle Call internal GDB demangler routine to
8869 demangle a C++ link name and prints the result.
8870 maintenance print type Print a type chain for a given symbol
8872 * Change to .gdbinit file processing
8874 We now read the $HOME/.gdbinit file before processing the argv arguments
8875 (e.g. reading symbol files or core files). This allows global parameters to
8876 be set, which will apply during the symbol reading. The ./.gdbinit is still
8877 read after argv processing.
8879 * New hosts supported
8881 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8883 GNU/Linux support i386-unknown-linux or linux
8885 We are also including code to support the HP/PA running BSD and HPUX. This
8886 is almost guaranteed not to work, as we didn't have time to test or build it
8887 for this release. We are including it so that the more adventurous (or
8888 masochistic) of you can play with it. We also had major problems with the
8889 fact that the compiler that we got from HP doesn't support the -g option.
8892 * New targets supported
8894 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8896 * More smarts about finding #include files
8898 GDB now remembers the compilation directory for all include files, and for
8899 all files from which C is generated (like yacc and lex sources). This
8900 greatly improves GDB's ability to find yacc/lex sources, and include files,
8901 especially if you are debugging your program from a directory different from
8902 the one that contains your sources.
8904 We also fixed a bug which caused difficulty with listing and setting
8905 breakpoints in include files which contain C code. (In the past, you had to
8906 try twice in order to list an include file that you hadn't looked at before.)
8908 * Interesting infernals change
8910 GDB now deals with arbitrary numbers of sections, where the symbols for each
8911 section must be relocated relative to that section's landing place in the
8912 target's address space. This work was needed to support ELF with embedded
8913 stabs used by Solaris-2.0.
8915 * Bug fixes (of course!)
8917 There have been loads of fixes for the following things:
8918 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8919 i960, stabs, DOS(GO32), procfs, etc...
8921 See the ChangeLog for details.
8923 *** Changes in GDB-4.5:
8925 * New machines supported (host and target)
8927 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8929 SGI Irix-4.x mips-sgi-irix4 or iris4
8931 * New malloc package
8933 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8934 Mmalloc is capable of handling multiple heaps of memory. It is also
8935 capable of saving a heap to a file, and then mapping it back in later.
8936 This can be used to greatly speedup the startup of GDB by using a
8937 pre-parsed symbol table which lives in a mmalloc managed heap. For
8938 more details, please read mmalloc/mmalloc.texi.
8942 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8943 'help info proc' for details.
8945 * MIPS ecoff symbol table format
8947 The code that reads MIPS symbol table format is now supported on all hosts.
8948 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8951 * File name changes for MS-DOS
8953 Many files in the config directories have been renamed to make it easier to
8954 support GDB on MS-DOSe systems (which have very restrictive file name
8955 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8956 environment) is close to working but has some remaining problems. Note
8957 that debugging of DOS programs is not supported, due to limitations
8958 in the ``operating system'', but it can be used to host cross-debugging.
8960 * Cross byte order fixes
8962 Many fixes have been made to support cross debugging of Sparc and MIPS
8963 targets from hosts whose byte order differs.
8965 * New -mapped and -readnow options
8967 If memory-mapped files are available on your system through the 'mmap'
8968 system call, you can use the -mapped option on the `file' or
8969 `symbol-file' commands to cause GDB to write the symbols from your
8970 program into a reusable file. If the program you are debugging is
8971 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8972 Future GDB debugging sessions will notice the presence of this file,
8973 and will quickly map in symbol information from it, rather than reading
8974 the symbol table from the executable program. Using the '-mapped'
8975 option in a GDB `file' or `symbol-file' command has the same effect as
8976 starting GDB with the '-mapped' command-line option.
8978 You can cause GDB to read the entire symbol table immediately by using
8979 the '-readnow' option with any of the commands that load symbol table
8980 information (or on the GDB command line). This makes the command
8981 slower, but makes future operations faster.
8983 The -mapped and -readnow options are typically combined in order to
8984 build a `fred.syms' file that contains complete symbol information.
8985 A simple GDB invocation to do nothing but build a `.syms' file for future
8988 gdb -batch -nx -mapped -readnow programname
8990 The `.syms' file is specific to the host machine on which GDB is run.
8991 It holds an exact image of GDB's internal symbol table. It cannot be
8992 shared across multiple host platforms.
8994 * longjmp() handling
8996 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8997 siglongjmp() without losing control. This feature has not yet been ported to
8998 all systems. It currently works on many 386 platforms, all MIPS-based
8999 platforms (SGI, DECstation, etc), and Sun3/4.
9003 Preliminary work has been put in to support the new Solaris OS from Sun. At
9004 this time, it can control and debug processes, but it is not capable of
9009 As always, many many bug fixes. The major areas were with g++, and mipsread.
9010 People using the MIPS-based platforms should experience fewer mysterious
9011 crashes and trashed symbol tables.
9013 *** Changes in GDB-4.4:
9015 * New machines supported (host and target)
9017 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
9019 BSD Reno on Vax vax-dec-bsd
9020 Ultrix on Vax vax-dec-ultrix
9022 * New machines supported (target)
9024 AMD 29000 embedded, using EBMON a29k-none-none
9028 GDB continues to improve its handling of C++. `References' work better.
9029 The demangler has also been improved, and now deals with symbols mangled as
9030 per the Annotated C++ Reference Guide.
9032 GDB also now handles `stabs' symbol information embedded in MIPS
9033 `ecoff' symbol tables. Since the ecoff format was not easily
9034 extensible to handle new languages such as C++, this appeared to be a
9035 good way to put C++ debugging info into MIPS binaries. This option
9036 will be supported in the GNU C compiler, version 2, when it is
9039 * New features for SVR4
9041 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
9042 shared libraries. Debugging dynamically linked programs should present
9043 only minor differences from debugging statically linked programs.
9045 The `info proc' command will print out information about any process
9046 on an SVR4 system (including the one you are debugging). At the moment,
9047 it prints the address mappings of the process.
9049 If you bring up GDB on another SVR4 system, please send mail to
9050 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
9052 * Better dynamic linking support in SunOS
9054 Reading symbols from shared libraries which contain debugging symbols
9055 now works properly. However, there remain issues such as automatic
9056 skipping of `transfer vector' code during function calls, which
9057 make it harder to debug code in a shared library, than to debug the
9058 same code linked statically.
9062 GDB is now using the latest `getopt' routines from the FSF. This
9063 version accepts the -- prefix for options with long names. GDB will
9064 continue to accept the old forms (-option and +option) as well.
9065 Various single letter abbreviations for options have been explicity
9066 added to the option table so that they won't get overshadowed in the
9067 future by other options that begin with the same letter.
9071 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
9072 Many assorted bugs have been handled. Many more remain to be handled.
9073 See the various ChangeLog files (primarily in gdb and bfd) for details.
9076 *** Changes in GDB-4.3:
9078 * New machines supported (host and target)
9080 Amiga 3000 running Amix m68k-cbm-svr4 or amix
9081 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
9082 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
9084 * Almost SCO Unix support
9086 We had hoped to support:
9087 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
9088 (except for core file support), but we discovered very late in the release
9089 that it has problems with process groups that render gdb unusable. Sorry
9090 about that. I encourage people to fix it and post the fixes.
9092 * Preliminary ELF and DWARF support
9094 GDB can read ELF object files on System V Release 4, and can handle
9095 debugging records for C, in DWARF format, in ELF files. This support
9096 is preliminary. If you bring up GDB on another SVR4 system, please
9097 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
9102 GDB now uses the latest `readline' library. One user-visible change
9103 is that two tabs will list possible command completions, which previously
9104 required typing M-? (meta-question mark, or ESC ?).
9108 The `stepi' bug that many of you noticed has been squashed.
9109 Many bugs in C++ have been handled. Many more remain to be handled.
9110 See the various ChangeLog files (primarily in gdb and bfd) for details.
9112 * State of the MIPS world (in case you wondered):
9114 GDB can understand the symbol tables emitted by the compilers
9115 supplied by most vendors of MIPS-based machines, including DEC. These
9116 symbol tables are in a format that essentially nobody else uses.
9118 Some versions of gcc come with an assembler post-processor called
9119 mips-tfile. This program is required if you want to do source-level
9120 debugging of gcc-compiled programs. I believe FSF does not ship
9121 mips-tfile with gcc version 1, but it will eventually come with gcc
9124 Debugging of g++ output remains a problem. g++ version 1.xx does not
9125 really support it at all. (If you're lucky, you should be able to get
9126 line numbers and stack traces to work, but no parameters or local
9127 variables.) With some work it should be possible to improve the
9130 When gcc version 2 is released, you will have somewhat better luck.
9131 However, even then you will get confusing results for inheritance and
9134 We will eventually provide full debugging of g++ output on
9135 DECstations. This will probably involve some kind of stabs-in-ecoff
9136 encapulation, but the details have not been worked out yet.
9139 *** Changes in GDB-4.2:
9141 * Improved configuration
9143 Only one copy of `configure' exists now, and it is not self-modifying.
9144 Porting BFD is simpler.
9148 The `step' and `next' commands now only stop at the first instruction
9149 of a source line. This prevents the multiple stops that used to occur
9150 in switch statements, for-loops, etc. `Step' continues to stop if a
9151 function that has debugging information is called within the line.
9155 Lots of small bugs fixed. More remain.
9157 * New host supported (not target)
9159 Intel 386 PC clone running Mach i386-none-mach
9162 *** Changes in GDB-4.1:
9164 * Multiple source language support
9166 GDB now has internal scaffolding to handle several source languages.
9167 It determines the type of each source file from its filename extension,
9168 and will switch expression parsing and number formatting to match the
9169 language of the function in the currently selected stack frame.
9170 You can also specifically set the language to be used, with
9171 `set language c' or `set language modula-2'.
9175 GDB now has preliminary support for the GNU Modula-2 compiler,
9176 currently under development at the State University of New York at
9177 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
9178 continue through the fall of 1991 and into 1992.
9180 Other Modula-2 compilers are currently not supported, and attempting to
9181 debug programs compiled with them will likely result in an error as the
9182 symbol table is read. Feel free to work on it, though!
9184 There are hooks in GDB for strict type checking and range checking,
9185 in the `Modula-2 philosophy', but they do not currently work.
9189 GDB can now write to executable and core files (e.g. patch
9190 a variable's value). You must turn this switch on, specify
9191 the file ("exec foo" or "core foo"), *then* modify it, e.g.
9192 by assigning a new value to a variable. Modifications take
9195 * Automatic SunOS shared library reading
9197 When you run your program, GDB automatically determines where its
9198 shared libraries (if any) have been loaded, and reads their symbols.
9199 The `share' command is no longer needed. This also works when
9200 examining core files.
9204 You can specify the number of lines that the `list' command shows.
9207 * New machines supported (host and target)
9209 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
9210 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
9211 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
9213 * New hosts supported (not targets)
9215 IBM RT/PC: romp-ibm-aix or rtpc
9217 * New targets supported (not hosts)
9219 AMD 29000 embedded with COFF a29k-none-coff
9220 AMD 29000 embedded with a.out a29k-none-aout
9221 Ultracomputer remote kernel debug a29k-nyu-kern
9223 * New remote interfaces
9229 *** Changes in GDB-4.0:
9233 Wide output is wrapped at good places to make the output more readable.
9235 Gdb now supports cross-debugging from a host machine of one type to a
9236 target machine of another type. Communication with the target system
9237 is over serial lines. The ``target'' command handles connecting to the
9238 remote system; the ``load'' command will download a program into the
9239 remote system. Serial stubs for the m68k and i386 are provided. Gdb
9240 also supports debugging of realtime processes running under VxWorks,
9241 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
9242 stub on the target system.
9244 New CPUs supported include the AMD 29000 and Intel 960.
9246 GDB now reads object files and symbol tables via a ``binary file''
9247 library, which allows a single copy of GDB to debug programs of multiple
9248 object file types such as a.out and coff.
9250 There is now a GDB reference card in "doc/refcard.tex". (Make targets
9251 refcard.dvi and refcard.ps are available to format it).
9254 * Control-Variable user interface simplified
9256 All variables that control the operation of the debugger can be set
9257 by the ``set'' command, and displayed by the ``show'' command.
9259 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
9260 ``Show prompt'' produces the response:
9261 Gdb's prompt is new-gdb=>.
9263 What follows are the NEW set commands. The command ``help set'' will
9264 print a complete list of old and new set commands. ``help set FOO''
9265 will give a longer description of the variable FOO. ``show'' will show
9266 all of the variable descriptions and their current settings.
9268 confirm on/off: Enables warning questions for operations that are
9269 hard to recover from, e.g. rerunning the program while
9270 it is already running. Default is ON.
9272 editing on/off: Enables EMACS style command line editing
9273 of input. Previous lines can be recalled with
9274 control-P, the current line can be edited with control-B,
9275 you can search for commands with control-R, etc.
9278 history filename NAME: NAME is where the gdb command history
9279 will be stored. The default is .gdb_history,
9280 or the value of the environment variable
9283 history size N: The size, in commands, of the command history. The
9284 default is 256, or the value of the environment variable
9287 history save on/off: If this value is set to ON, the history file will
9288 be saved after exiting gdb. If set to OFF, the
9289 file will not be saved. The default is OFF.
9291 history expansion on/off: If this value is set to ON, then csh-like
9292 history expansion will be performed on
9293 command line input. The default is OFF.
9295 radix N: Sets the default radix for input and output. It can be set
9296 to 8, 10, or 16. Note that the argument to "radix" is interpreted
9297 in the current radix, so "set radix 10" is always a no-op.
9299 height N: This integer value is the number of lines on a page. Default
9300 is 24, the current `stty rows'' setting, or the ``li#''
9301 setting from the termcap entry matching the environment
9304 width N: This integer value is the number of characters on a line.
9305 Default is 80, the current `stty cols'' setting, or the ``co#''
9306 setting from the termcap entry matching the environment
9309 Note: ``set screensize'' is obsolete. Use ``set height'' and
9310 ``set width'' instead.
9312 print address on/off: Print memory addresses in various command displays,
9313 such as stack traces and structure values. Gdb looks
9314 more ``symbolic'' if you turn this off; it looks more
9315 ``machine level'' with it on. Default is ON.
9317 print array on/off: Prettyprint arrays. New convenient format! Default
9320 print demangle on/off: Print C++ symbols in "source" form if on,
9323 print asm-demangle on/off: Same, for assembler level printouts
9326 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
9329 * Support for Epoch Environment.
9331 The epoch environment is a version of Emacs v18 with windowing. One
9332 new command, ``inspect'', is identical to ``print'', except that if you
9333 are running in the epoch environment, the value is printed in its own
9337 * Support for Shared Libraries
9339 GDB can now debug programs and core files that use SunOS shared libraries.
9340 Symbols from a shared library cannot be referenced
9341 before the shared library has been linked with the program (this
9342 happens after you type ``run'' and before the function main() is entered).
9343 At any time after this linking (including when examining core files
9344 from dynamically linked programs), gdb reads the symbols from each
9345 shared library when you type the ``sharedlibrary'' command.
9346 It can be abbreviated ``share''.
9348 sharedlibrary REGEXP: Load shared object library symbols for files
9349 matching a unix regular expression. No argument
9350 indicates to load symbols for all shared libraries.
9352 info sharedlibrary: Status of loaded shared libraries.
9357 A watchpoint stops execution of a program whenever the value of an
9358 expression changes. Checking for this slows down execution
9359 tremendously whenever you are in the scope of the expression, but is
9360 quite useful for catching tough ``bit-spreader'' or pointer misuse
9361 problems. Some machines such as the 386 have hardware for doing this
9362 more quickly, and future versions of gdb will use this hardware.
9364 watch EXP: Set a watchpoint (breakpoint) for an expression.
9366 info watchpoints: Information about your watchpoints.
9368 delete N: Deletes watchpoint number N (same as breakpoints).
9369 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
9370 enable N: Re-enables watchpoint number N (same as breakpoints).
9373 * C++ multiple inheritance
9375 When used with a GCC version 2 compiler, GDB supports multiple inheritance
9378 * C++ exception handling
9380 Gdb now supports limited C++ exception handling. Besides the existing
9381 ability to breakpoint on an exception handler, gdb can breakpoint on
9382 the raising of an exception (before the stack is peeled back to the
9385 catch FOO: If there is a FOO exception handler in the dynamic scope,
9386 set a breakpoint to catch exceptions which may be raised there.
9387 Multiple exceptions (``catch foo bar baz'') may be caught.
9389 info catch: Lists all exceptions which may be caught in the
9390 current stack frame.
9393 * Minor command changes
9395 The command ``call func (arg, arg, ...)'' now acts like the print
9396 command, except it does not print or save a value if the function's result
9397 is void. This is similar to dbx usage.
9399 The ``up'' and ``down'' commands now always print the frame they end up
9400 at; ``up-silently'' and `down-silently'' can be used in scripts to change
9401 frames without printing.
9403 * New directory command
9405 'dir' now adds directories to the FRONT of the source search path.
9406 The path starts off empty. Source files that contain debug information
9407 about the directory in which they were compiled can be found even
9408 with an empty path; Sun CC and GCC include this information. If GDB can't
9409 find your source file in the current directory, type "dir .".
9411 * Configuring GDB for compilation
9413 For normal use, type ``./configure host''. See README or gdb.texinfo
9416 GDB now handles cross debugging. If you are remotely debugging between
9417 two different machines, type ``./configure host -target=targ''.
9418 Host is the machine where GDB will run; targ is the machine
9419 where the program that you are debugging will run.