1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 16
6 * Debugger Adapter Protocol changes
8 ** GDB now supports the "completions" request.
10 * "set style" commands now supports numeric format for basic colors
11 from 0 to 255 and #RRGGBB format for TrueColor.
13 * New built-in convenience variable $_colorsupport provides comma-separated
14 list of color space names supported by terminal. Each color space name is one
15 of monochrome, ansi_8color, aixterm_16color, xterm_256color or rgb_24bit.
16 It is handy for conditionally using styling colors based on terminal features.
19 (gdb) if $_regex ($_colorsupport, ".*(^|,)rgb_24bit($|,).*")
20 >set style filename background #FACADE
22 >if $_regex ($_colorsupport, ".*(^|,)xterm_256color($|,).*")
23 >set style filename background 224
25 >set style filename background red
29 * UST (static tracepoint) support from gdbserver has been removed.
31 * Linux checkpoint code has been updated to work with multiple inferiors.
33 * The gcore and gdb-add-index scripts now have a -v or --version
34 option, which prints the version number, and then exits. As well as
35 a -h or --help option, which prints each options and a brief
38 * On systems that support linker namespaces, the output of the command
39 "info sharedlibraries" may add one more column, NS, which identifies the
40 namespace into which the library was loaded, if more than one namespace
43 * New built-in convenience variables $_active_linker_namespaces and
44 $_linker_namespace. These show the number of active linker
45 namespaces, and the namespace to which the current location belongs to.
46 In systems that don't support linker namespaces, these always return
47 the integers 1 and 0 respectively.
49 * Add record full support for rv64gc architectures
53 maintenance check psymtabs
54 Renamed from maintenance check-psymtabs
56 maintenance check symtabs
57 Renamed from maintenance check-symtabs
59 maintenance canonicalize
60 Show the canonical form of a C++ name.
62 maintenance set console-translation-mode <binary|text>
63 maintenance show console-translation-mode
64 Controls the translation mode of GDB stdout/stderr. MS-Windows only. In
65 binary mode, no translation is done. In text mode, a Line Feed is
66 translated into a Carriage Return-Line Feed combination.
68 set riscv numeric-register-names on|off
69 show riscv numeric-register-names
70 Controls whether GDB refers to risc-v registers by their numeric names
71 (e.g 'x1') or their abi names (e.g. 'ra').
72 Defaults to 'off', matching the old behaviour (abi names).
74 set style emoji on|off|auto
76 Controls whether GDB can display emoji. The default is "auto",
77 which means emoji will be displayed in some situations when
78 the host charset is UTF-8.
80 set style warning-prefix STRING
81 set style error-prefix STRING
82 These commands control the prefix that is printed before warnings
83 and errors, respectively. This functionality is intended for use
84 with emoji display, and so the prefixes are only displayed if emoji
87 info linker-namespaces
88 info linker-namespaces [[N]]
89 Print information about the given linker namespace (identified as N),
90 or about all the namespaces if no argument is given.
95 On Linux and FreeBSD, the addresses shown in the output of this
96 command are now for the full memory range allocated to the shared
99 info threads [-gid] [-stopped] [-running] [ID]...
100 If no threads match the given ID(s) or filter options, GDB now prints
104 without printing the provided arguments. The newly added '-stopped'
105 option makes GDB list the stopped threads only. Similarly,
106 '-running' makes GDB list the running threads only. If both options
107 are given together, both stopped and running threads are listed.
108 These new flags can be useful to get a reduced list when there is a
109 large number of threads.
111 * GDB-internal Thread Local Storage (TLS) support
113 ** Linux targets for the x86_64, aarch64, ppc64, s390x, and riscv
114 architectures now have GDB-internal support for TLS address
115 lookup in addition to that traditionally provided by the
116 libthread_db library. This internal support works for programs
117 linked against either the GLIBC or MUSL C libraries. For
118 programs linked against MUSL, this new internal support provides
119 new debug functionality, allowing access to TLS variables, due to
120 the fact that MUSL does not implement the libthread_db library.
121 Internal TLS support is also useful in cross-debugging
122 situations, debugging statically linked binaries, and debugging
123 programs linked against GLIBC 2.33 and earlier, but which are not
124 linked against libpthread.
126 ** The command 'maint set force-internal-tls-address-lookup on' may
127 be used to force the internal TLS lookup mechanisms to be used.
128 Otherwise, TLS lookup via libthread_db will still be preferred,
133 ** GDB no longer supports Python versions less than 3.4.
135 ** New class gdb.Color for dealing with colors.
137 ** New constant gdb.PARAM_COLOR represents color type of a
138 gdb.Parameter.value. Parameter's value is gdb.Color instance.
140 ** The memory_source argument (the second argument) has been removed
141 from gdb.disassembler.builtin_disassemble. This argument was
142 never used by GDB, and was added by mistake. The unused argument
143 was never documented in the GDB manual, so users should not have
146 ** gdb.execute has an additional 'styling' argument. When True, then
147 output will be styled. The default for this argument is True
148 when output is going to standard output, and False when output is
151 ** Setting the documentation string (__doc__) of a gdb.Parameter
152 sub-class to the empty string, means GDB will only display the
153 set_doc or show_doc strings in the set/show help output.
155 ** New gdb.ParameterPrefix class. This can be used to create 'set'
156 and 'show' gdb.Command prefixes, suitable for use with new
159 ** Prefix commands (gdb.Command sub-classes) that don't have an
160 invoke method will now behave like builtin prefix commands when
161 invoked without a sub-command name. This means printing the help
162 text for all sub-commands, unless the prefix command is a 'show'
163 command, in which case the value of all sub-commands is printed.
165 ** New gdb.warning() function that takes a string and prints it as a
166 warning, with GDB's standard 'warning' prefix.
170 ** New type <gdb:color> for dealing with colors.
172 ** New constant PARAM_COLOR represents color type of a value
173 of a <gdb:parameter> object. Parameter's value is <gdb::color> instance.
175 ** Eliding the #:doc string from make-parameter now means that GDB
176 will use a default documentation string. Setting #:doc to the
177 empty string for make-parameter means GDB will only display the
178 #:set_doc or #:show_doc strings in the set/show help output.
180 ** Prefix commands (using make-command) that don't have a #:invoke
181 property will now behave like builtin prefix commands when
182 invoked without a sub-command name. This means printing the help
183 text for all sub-commands, unless the prefix command is a 'show'
184 command, in which case the value of all sub-commands is printed.
188 binary-upload in qSupported reply
189 If the stub sends back 'binary-upload+' in it's qSupported reply,
190 then GDB will, where possible, make use of the 'x' packet. If the
191 stub doesn't report this feature supported, then GDB will not use
195 Return information about files on the remote system. Like
196 vFile:stat but if the filename is a symbolic link, return
197 information about the link itself, the file the link refers to.
199 * Changed remote packets
202 The XML that is sent as a response can now include an "id_str"
203 attribute for a thread element. The attribute indicates what GDB
204 should print as the target ID of the thread, for example in the
205 "info threads" command or when switching to the thread.
208 Previously, gdbserver incorrectly implemented this packet using
209 lstat rather than stat. This has now been corrected. The
210 documentation has also been clarified.
214 ** The =library-unloaded event now includes the 'ranges' field, which
215 has the same meaning as for the =library-loaded event.
217 ** The =library-unloaded event now includes the 'still-in-use' field.
218 This field is 'true' when a library is unloaded (removed from the
219 inferior's list of loaded libraries), but the mapping within the
220 inferior's address space is retained, as the library was mapped
221 multiple times, and the same mapping was being reused. In all
222 other cases, this field will have the value 'false'.
224 * Support for stabs debugging format and the a.out/dbx object format is
225 deprecated, and will be removed in GDB 18.
227 * A new configure option was added, allowing support for the compile
228 subsystem to be disabled at configure time, in the form of
229 --disable-gdb-compile.
231 * A new configure option was added, allowing support for DWARF debug
232 information to be disabled at configure time. The flag is
233 --disable-gdb-dwarf-support.
235 * A new configure option was added, allowing support for mdebug/ecoff
236 debug information to be disabled at configure time. The flag to do
237 that is --disable-gdb-mdebug-support.
239 * The Alpha target now supports target descriptions.
241 *** Changes in GDB 16
243 * Support for Nios II targets has been removed as this architecture
244 has been EOL'ed by Intel.
246 * GDB now supports watchpoints for tagged data pointers (see
247 https://en.wikipedia.org/wiki/Tagged_pointer) on amd64, such as the
248 one used by the Linear Address Masking (LAM) feature provided by
251 * Debugging support for Intel MPX has been removed. This includes the
253 ** MPX register support
254 ** the commands "show/set mpx bound" (deprecated since GDB 15)
255 ** i386 and amd64 implementation of the hooks report_signal_info and
258 * GDB now supports printing of asynchronous events from the Intel Processor
259 Trace during 'record instruction-history', 'record function-call-history'
260 and all stepping commands. This can be controlled with the new
261 "set record btrace pt event-tracing" command.
263 * GDB now supports printing of ptwrite payloads from the Intel Processor
264 Trace during 'record instruction-history', 'record function-call-history'
265 and all stepping commands. The payload is also accessible in Python as a
266 RecordAuxiliary object. Printing is customizable via a ptwrite filter
267 function in Python. By default, the raw ptwrite payload is printed for
268 each ptwrite that is encountered.
270 * For breakpoints that are created in the 'pending' state, any
271 'thread' or 'task' keywords are parsed at the time the breakpoint is
272 created, rather than at the time the breakpoint becomes non-pending.
274 * Thread-specific breakpoints are only inserted into the program space
275 in which the thread of interest is running. In most cases program
276 spaces are unique for each inferior, so this means that
277 thread-specific breakpoints will usually only be inserted for the
278 inferior containing the thread of interest. The breakpoint will
279 be hit no less than before.
281 * For ARM targets, the offset of the pc in the jmp_buf has been fixed to match
282 glibc 2.20 and later. This should only matter when not using libc probes.
283 This may cause breakage when using an incompatible libc, like uclibc or
284 newlib, or an older glibc.
286 * MTE (Memory Tagging Extension) debugging is now supported on AArch64 baremetal
289 * Remove support (native and remote) for QNX Neutrino (triplet
292 * In a record session, when a forward emulation reaches the end of the reverse
293 history, the warning message has been changed to indicate that the end of the
294 history has been reached. It also specifies that the forward execution can
295 continue, and the recording will also continue.
297 * The Ada 'Object_Size attribute is now supported.
299 * Support for process record/replay and reverse debugging on loongarch*-linux*
300 targets has been added.
302 * New bash script gstack uses GDB to print stack traces of running processes.
306 ** Added gdb.record.clear. Clears the trace data of the current recording.
307 This forces re-decoding of the trace for successive commands.
309 ** Added the new event source gdb.tui_enabled.
311 ** New module gdb.missing_objfile that facilitates dealing with
312 missing objfiles when opening a core-file.
314 ** New function gdb.missing_objfile.register_handler that can
315 register an instance of a sub-class of
316 gdb.missing_debug.MissingObjfileHandler as a handler for missing
319 ** New class gdb.missing_objfile.MissingObjfileHandler which can be
320 sub-classed to create handlers for missing objfiles.
322 ** The 'signed' argument to gdb.Architecture.integer_type() will no
323 longer accept non-bool types.
325 ** The gdb.MICommand.installed property can only be set to True or
328 ** The 'qualified' argument to gdb.Breakpoint constructor will no
329 longer accept non-bool types.
331 ** Added the gdb.Symbol.is_artificial attribute.
333 ** Added gdb.Block.subblocks. Returns a list of blocks contained in that
336 ** Added gdb.Symbol.domain. Contains the domain of the symbol.
338 ** Added gdb.Architecture.void_type. Returns a gdb.Type representing "void"
339 type for that architecture.
341 * Debugger Adapter Protocol changes
343 ** The "scopes" request will now return a scope holding global
344 variables from the stack frame's compilation unit.
346 ** The "scopes" request will return a "returnValue" scope holding
347 the return value from the latest "stepOut" command, when
350 ** The "launch" and "attach" requests were rewritten in accordance
351 with some clarifications to the spec. Now they can be sent at
352 any time after the "initialized" event, but will not take effect
353 (or send a response) until after the "configurationDone" request
356 ** The "variables" request will not return artificial symbols.
360 show jit-reader-directory
361 Show the name of the directory that "jit-reader-load" uses for
364 set style line-number foreground COLOR
365 set style line-number background COLOR
366 set style line-number intensity VALUE
367 Control the styling of line numbers printed by GDB.
369 set style command foreground COLOR
370 set style command background COLOR
371 set style command intensity VALUE
372 Control the styling of GDB commands when displayed by GDB.
374 set style title foreground COLOR
375 set style title background COLOR
376 set style title intensity VALUE
377 This style now applies to the header line of lists, for example the
378 first line of the output of "info breakpoints". Previous uses of
379 this style have been replaced with the new "command" style.
381 set warn-language-frame-mismatch [on|off]
382 show warn-language-frame-mismatch
383 Control the warning that is emitted when specifying a language that
384 does not match the current frame's language.
386 maintenance info inline-frames [ADDRESS]
387 New command which displays GDB's inline-frame information for the
388 current address, or for ADDRESS if specified. The output identifies
389 inlined frames which start at the specified address.
391 maintenance info blocks [ADDRESS]
392 New command which displays information about all of the blocks at
393 ADDRESS, or at the current address if ADDRESS is not given. Blocks
394 are listed starting at the inner global block out to the most inner
397 maintenance frame-unwinder disable [-all | -name NAME | [-class] CLASS]
398 maintenance frame-unwinder enable [-all | -name NAME | [-class] CLASS]
399 Enable or disable frame unwinders. This is only meant to be used when
400 testing unwinders themselves, and you want to ensure that a fallback
401 algorithm won't obscure a regression. GDB is not expected to behave
402 well if you try to execute the inferior with unwinders disabled.
404 info missing-objfile-handlers
405 List all the registered missing-objfile handlers.
407 enable missing-objfile-handler LOCUS HANDLER
408 disable missing-objfile-handler LOCUS HANDLER
409 Enable or disable a missing-objfile handler with a name matching the
410 regular expression HANDLER, in LOCUS.
412 LOCUS can be 'global' to operate on global missing-objfile handler,
413 'progspace' to operate on handlers within the current program space,
414 or can be a regular expression which is matched against the filename
415 of the primary executable in each program space.
420 This command now supports file-name completion.
422 remove-symbol-file -a ADDRESS
423 The ADDRESS expression can now be a full expression consisting of
424 multiple terms, e.g. 'function + 0x1000' (without quotes),
425 previously only a single term could be given.
434 These commands now require their filename argument to be quoted if
435 it contains white space or quote characters. If the argument
436 contains no such special characters then quoting is not required.
438 maintenance print remote-registers
439 Add an "Expedited" column to the output of the command. It indicates
440 which registers were included in the last stop reply packet received by
443 maintenance info frame-unwinders
444 Add a CLASS column to the output. This class is a somewhat arbitrary
445 grouping of unwinders, based on which area of GDB adds the unwinder.
446 Also add an ENABLED column, that will show if the unwinder is enabled
449 maintenance set dwarf unwinders (on|off)
450 This command has been removed because the same functionality can be
451 achieved with maint frame-unwinder (enable|disable) DEBUGINFO.
453 maintenance show dwarf unwinders
454 This command has been removed since the functionality can be achieved
455 by checking the last column of maint info frame-unwinders.
458 Now includes the version of GNU Readline library that GDB is using.
463 Return information about files on the remote system. Like
464 vFile:fstat but takes a filename rather than an open file
468 Given ADDR and LENGTH, fetch LENGTH units from the memory at address
469 ADDR and send the fetched data in binary format. This packet is
470 equivalent to 'm', except that the data in the response are in
473 *** Changes in GDB 15
475 * The MPX commands "show/set mpx bound" have been deprecated, as Intel
476 listed MPX as removed in 2019.
478 * Building GDB and GDBserver now requires a C++17 compiler.
479 For example, GCC 9 or later.
481 * GDB index now contains information about the main function. This speeds up
482 startup when it is being used for some large binaries.
484 * On hosts where threading is available, DWARF reading is now done in
485 the background, resulting in faster startup. This can be controlled
486 using "maint set dwarf synchronous".
491 Attempting to use both the 'r' and 'b' flags with the disassemble
492 command will now give an error. Previously the 'b' flag would
493 always override the 'r' flag.
497 GDB now generates sparse core files, on systems that support it.
499 maintenance info line-table
500 Add an EPILOGUE-BEGIN column to the output of the command. It indicates
501 if the line is considered the start of the epilogue, and thus a point at
502 which the frame can be considered destroyed.
504 set unwindonsignal on|off
506 These commands are now aliases for the new set/show unwind-on-signal.
509 This command now gives an error if any unexpected arguments are
510 found after the command.
513 When using the command "list ." in a location that has no debug information
514 or no file loaded, GDB now says that there is no debug information to print
515 lines. This makes it more obvious that there is no information, as opposed
516 to implying there is no inferior loaded.
520 info missing-debug-handler
521 List all the registered missing debug handlers.
523 enable missing-debug-handler LOCUS HANDLER
524 disable missing-debug-handler LOCUS HANDLER
525 Enable or disable a missing debug handler with a name matching the
526 regular expression HANDLER, in LOCUS.
528 LOCUS can be 'global' to operate on global missing debug handler,
529 'progspace' to operate on handlers within the current program space,
530 or can be a regular expression which is matched against the filename
531 of the primary executable in each program space.
533 maintenance info linux-lwps
534 List all LWPs under control of the linux-nat target.
536 set remote thread-options-packet
537 show remote thread-options-packet
538 Set/show the use of the thread options packet.
540 set direct-call-timeout SECONDS
541 show direct-call-timeout
542 set indirect-call-timeout SECONDS
543 show indirect-call-timeout
544 These new settings can be used to limit how long GDB will wait for
545 an inferior function call to complete. The direct timeout is used
546 for inferior function calls from e.g. 'call' and 'print' commands,
547 while the indirect timeout is used for inferior function calls from
548 within a conditional breakpoint expression.
550 The default for the direct timeout is unlimited, while the default
551 for the indirect timeout is 30 seconds.
553 These timeouts will only have an effect for targets that are
554 operating in async mode. For non-async targets the timeouts are
555 ignored, GDB will wait indefinitely for an inferior function to
556 complete, unless interrupted by the user using Ctrl-C.
558 set unwind-on-timeout on|off
559 show unwind-on-timeout
560 These commands control whether GDB should unwind the stack when a
561 timeout occurs during an inferior function call. The default is
562 off, in which case the inferior will remain in the frame where the
563 timeout occurred. When on, GDB will unwind the stack removing the
564 dummy frame that was added for the inferior call, and restoring the
565 inferior state to how it was before the inferior call started.
567 set unwind-on-signal on|off
568 show unwind-on-signal
569 These new commands replaces the existing set/show unwindonsignal. The
570 old command is maintained as an alias.
572 * New features in the GDB remote stub, GDBserver
574 ** The --remote-debug and --event-loop-debug command line options
577 ** The --debug command line option now takes an optional comma
578 separated list of components to emit debug for. The currently
579 supported components are: all, threads, event-loop, and remote.
580 If no components are given then threads is assumed.
582 ** The 'monitor set remote-debug' and 'monitor set event-loop-debug'
583 command have been removed.
585 ** The 'monitor set debug 0|1' command has been extended to take a
586 component name, e.g.: 'monitor set debug COMPONENT off|on'.
587 Possible component names are: all, threads, event-loop, and
592 ** New function gdb.notify_mi(NAME, DATA), that emits custom
593 GDB/MI async notification.
595 ** New read/write attribute gdb.Value.bytes that contains a bytes
596 object holding the contents of this value.
598 ** New module gdb.missing_debug that facilitates dealing with
599 objfiles that are missing any debug information.
601 ** New function gdb.missing_debug.register_handler that can register
602 an instance of a sub-class of gdb.missing_debug.MissingDebugInfo
603 as a handler for objfiles that are missing debug information.
605 ** New class gdb.missing_debug.MissingDebugInfo which can be
606 sub-classed to create handlers for objfiles with missing debug
609 ** Stop events now have a "details" attribute that holds a
610 dictionary that carries the same information as an MI "*stopped"
613 ** New function gdb.interrupt(), that interrupts GDB as if the user
616 ** New gdb.InferiorThread.ptid_string attribute. This read-only
617 attribute contains the string that appears in the 'Target Id'
618 column of the 'info threads' command output.
620 ** It is no longer possible to create new gdb.Progspace object using
621 'gdb.Progspace()', this will result in a TypeError. Progspace
622 objects can still be obtained through calling other API
623 functions, for example 'gdb.current_progspace()'.
625 ** User defined attributes can be added to a gdb.Inferior object,
626 these will be stored in the object's new Inferior.__dict__
629 ** User defined attributes can be added to a gdb.InferiorThread
630 object, these will be stored in the object's new
631 InferiorThread.__dict__ attribute.
633 ** New constants gdb.SYMBOL_TYPE_DOMAIN, gdb.SYMBOL_FUNCTION_DOMAIN,
634 and gdb.SEARCH_*_DOMAIN corresponding to all the existing symbol
635 domains. Symbol lookup can now search in multiple domains at
636 once, and can also narrowly search for just a type or function.
638 * Debugger Adapter Protocol changes
640 ** GDB now emits the "process" event.
642 ** GDB now supports the "cancel" request.
644 ** The "attach" request now supports specifying the program.
646 ** New command "set debug dap-log-level" controls DAP logging.
648 ** The "set debug dap-log-file" command is now documented. This
649 command was available in GDB 14 but not documented.
653 ** New constants SYMBOL_TYPE_DOMAIN, SYMBOL_FUNCTION_DOMAIN, and
654 SEARCH_*_DOMAIN corresponding to all the existing symbol domains.
655 Symbol lookup can now search in multiple domains at once, and can
656 also narrowly search for just a type or function.
660 New stop reason: clone
661 Indicates that a clone system call was executed.
664 Enable/disable optional event reporting, on a per-thread basis.
665 Currently supported options are GDB_THREAD_OPTION_CLONE, to enable
666 clone event reporting, and GDB_THREAD_OPTION_EXIT to enable thread
667 exit event reporting.
669 QThreadOptions in qSupported
670 The qSupported packet allows GDB to inform the stub it supports the
671 QThreadOptions packet, and the qSupported response can contain the
672 set of thread options the remote stub supports.
675 This new packet allows GDB to query the stub about a given address to check
676 if it is tagged or not. Many memory tagging-related GDB commands need to
677 perform this check before they read/write the allocation tag related to an
678 address. Currently, however, this is done through a 'vFile' request to read
679 the file /proc/<PID>/smaps and check if the address is in a region reported
680 as memory tagged. Since not all targets have a notion of what the smaps
681 file is about, this new packet provides a more generic way to perform such
684 *** Changes in GDB 14
686 * GDB now supports the AArch64 Scalable Matrix Extension 2 (SME2), which
687 includes a new 512 bit lookup table register named ZT0.
689 * GDB now supports the AArch64 Scalable Matrix Extension (SME), which includes
690 a new matrix register named ZA, a new thread register TPIDR2 and a new vector
691 length register SVG (streaming vector granule). GDB also supports tracking
692 ZA state across signal frames.
694 Some features are still under development or are dependent on ABI specs that
695 are still in alpha stage. For example, manual function calls with ZA state
696 don't have any special handling, and tracking of SVG changes based on
697 DWARF information is still not implemented, but there are plans to do so in
700 * GDB now recognizes the NO_COLOR environment variable and disables
701 styling according to the spec. See https://no-color.org/.
702 Styling can be re-enabled with "set style enabled on".
704 * The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
705 has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
708 * GDB now has some support for integer types larger than 64 bits.
710 * Removed targets and native configurations
712 GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
713 AIX version is now AIX 7.1.
715 * Multi-target feature configuration
717 GDB now supports the individual configuration of remote targets' feature
718 sets. Based on the current selection of a target, the commands 'set remote
719 <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
720 configure a target's feature packet and to display its configuration,
723 The individual packet sizes can be configured and shown using the commands
724 ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
725 ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
726 ** 'show remote memory-read-packet-size'
727 ** 'show remote memory-write-packet-size'.
729 The configuration of the packet itself, as well as the size of a memory-read
730 or memory-write packet applies to the currently selected target (if
731 available). If no target is selected, it applies to future remote
732 connections. Similarly, the show commands print the configuration of the
733 currently selected target. If no remote target is selected, the default
734 configuration for future connections is shown.
736 * GDB has initial built-in support for the Debugger Adapter Protocol.
737 This support requires that GDB be built with Python scripting
740 * For the break command, multiple uses of the 'thread' or 'task'
741 keywords will now give an error instead of just using the thread or
742 task id from the last instance of the keyword. E.g.:
743 break foo thread 1 thread 2
744 will now give an error rather than using 'thread 2'.
746 * For the watch command, multiple uses of the 'task' keyword will now
747 give an error instead of just using the task id from the last
748 instance of the keyword. E.g.:
749 watch my_var task 1 task 2
750 will now give an error rather than using 'task 2'. The 'thread'
751 keyword already gave an error when used multiple times with the
752 watch command, this remains unchanged.
754 * The 'set print elements' setting now helps when printing large arrays.
755 If an array would otherwise exceed max-value-size, but 'print elements'
756 is set such that the size of elements to print is less than or equal
757 to 'max-value-size', GDB will now still print the array, however only
758 'max-value-size' worth of data will be added into the value history.
760 * For both the break and watch commands, it is now invalid to use both
761 the 'thread' and 'task' keywords within the same command. For
762 example the following commands will now give an error:
763 break foo thread 1 task 1
764 watch var thread 2 task 3
766 * The printf command now accepts a '%V' output format which will
767 format an expression just as the 'print' command would. Print
768 options can be placed within '[...]' after the '%V' to modify how
769 the value is printed. E.g:
770 printf "%V", some_array
771 printf "%V[-array-indexes on]", some_array
772 will print the array without, or with array indexes included, just
773 as the array would be printed by the 'print' command. This
774 functionality is also available for dprintf when dprintf-style is
777 * When the printf command requires a string to be fetched from the
778 inferior, GDB now uses the existing 'max-value-size' setting to the
779 limit the memory allocated within GDB. The default 'max-value-size'
780 is 64k. To print longer strings you should increase
783 * The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
785 * The Ada 2022 target name symbol ('@') is now supported by the Ada
788 * The 'list' command now accepts '.' as an argument, which tells GDB to
789 print the location around the point of execution within the current frame.
790 If the inferior hasn't started yet, the command will print around the
791 beginning of the 'main' function.
793 * Using the 'list' command with no arguments in a situation where the
794 command would attempt to list past the end of the file now warns the
795 user that the end of file has been reached, refers the user to the
796 newly added '.' argument
798 * Breakpoints can now be inferior-specific. This is similar to the
799 existing thread-specific breakpoint support. Breakpoint conditions
800 can include the 'inferior' keyword followed by an inferior id (as
801 displayed in the 'info inferiors' output). It is invalid to use the
802 'inferior' keyword with either the 'thread' or 'task' keywords when
803 creating a breakpoint.
805 * New convenience function "$_shell", to execute a shell command and
806 return the result. This lets you run shell commands in expressions.
809 (gdb) p $_shell("true")
811 (gdb) p $_shell("false")
813 (gdb) break func if $_shell("some command") == 0
817 --additional-debug-dirs=PATHs
819 Provide a colon-separated list of additional directories to search for
820 separate debug info. These directories are added to the default value of
821 the 'debug-file-directory' GDB parameter.
825 set debug breakpoint on|off
826 show debug breakpoint
827 Print additional debug messages about breakpoint insertion and removal.
829 maintenance print record-instruction [ N ]
830 Print the recorded information for a given instruction. If N is not given
831 prints how GDB would undo the last instruction executed. If N is negative,
832 prints how GDB would undo the N-th previous instruction, and if N is
833 positive, it prints how GDB will redo the N-th following instruction.
835 maintenance info frame-unwinders
836 List the frame unwinders currently in effect, starting with the highest
839 maintenance wait-for-index-cache
840 Wait until all pending writes to the index cache have completed.
842 set always-read-ctf on|off
844 When off, CTF is only read if DWARF is not present. When on, CTF is
845 read regardless of whether DWARF is present. Off by default.
848 Get main symbol to identify entry point into program.
850 set tui mouse-events [on|off]
851 show tui mouse-events
852 When on (default), mouse clicks control the TUI and can be accessed by
853 Python extensions. When off, mouse clicks are handled by the terminal,
854 enabling terminal-native text selection.
858 ** MI version 1 has been removed.
860 ** mi now reports 'no-history' as a stop reason when hitting the end of the
861 reverse execution history.
863 ** When creating a thread-specific breakpoint using the '-p' option,
864 the -break-insert command would report the 'thread' field twice in
865 the reply. The content of both fields was always identical. This
866 has now been fixed; the 'thread' field will be reported just once
867 for thread-specific breakpoints, or not at all for breakpoints
868 without a thread restriction. The same is also true for the 'task'
869 field of an Ada task-specific breakpoint.
871 ** It is no longer possible to create a thread-specific breakpoint for
872 a thread that doesn't exist using '-break-insert -p ID'. Creating
873 breakpoints for non-existent threads is not allowed when using the
874 CLI, that the MI allowed it was a long standing bug, which has now
877 ** The '--simple-values' argument to the '-stack-list-arguments',
878 '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
879 commands now takes reference types into account: that is, a value is now
880 considered simple if it is neither an array, structure, or union, nor a
881 reference to an array, structure, or union. (Previously all references were
882 considered simple.) Support for this feature can be verified by using the
883 '-list-features' command, which should contain "simple-values-ref-types".
885 ** The -break-insert command now accepts a '-g thread-group-id' option
886 to allow for the creation of inferior-specific breakpoints.
888 ** The bkpt tuple, which appears in breakpoint-created notifications,
889 and in the result of the -break-insert command can now include an
890 optional 'inferior' field for both the main breakpoint, and each
891 location, when the breakpoint is inferior-specific.
895 ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
897 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
899 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
900 now be of type 'str' otherwise a TypeError will be raised.
902 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
903 values of type 'bool'. Changing this attribute will now
904 invalidate GDB's frame-cache, which means GDB will need to
905 rebuild its frame-cache when next required - either with, or
906 without the particular unwinder, depending on how 'enabled' was
909 ** New methods added to the gdb.PendingFrame class. These methods
910 have the same behavior as the corresponding methods on
911 gdb.Frame. The new methods are:
913 - gdb.PendingFrame.name: Return the name for the frame's
915 - gdb.PendingFrame.is_valid: Return True if the pending frame
917 - gdb.PendingFrame.pc: Return the $pc register value for this
919 - gdb.PendingFrame.language: Return a string containing the
920 language for this frame, or None.
921 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
922 object for the current location within the pending frame, or
924 - gdb.PendingFrame.block: Return a gdb.Block for the current
925 pending frame, or None.
926 - gdb.PendingFrame.function: Return a gdb.Symbol for the
927 current pending frame, or None.
929 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
930 now use either an integer or a gdb.Value object for each of its
931 'sp', 'pc', and 'special' attributes.
933 ** A new class gdb.unwinder.FrameId has been added. Instances of
934 this class are constructed with 'sp' (stack-pointer) and 'pc'
935 (program-counter) values, and can be used as the frame-id when
936 calling gdb.PendingFrame.create_unwind_info.
938 ** It is now no longer possible to sub-class the
939 gdb.disassembler.DisassemblerResult type.
941 ** The Disassembler API from the gdb.disassembler module has been
942 extended to include styling support:
944 - The DisassemblerResult class can now be initialized with a list
945 of parts. Each part represents part of the disassembled
946 instruction along with the associated style information. This
947 list of parts can be accessed with the new
948 DisassemblerResult.parts property.
950 - New constants gdb.disassembler.STYLE_* representing all the
951 different styles part of an instruction might have.
953 - New methods DisassembleInfo.text_part and
954 DisassembleInfo.address_part which are used to create the new
955 styled parts of a disassembled instruction.
957 - Changes are backwards compatible, the older API can still be
958 used to disassemble instructions without styling.
960 ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
961 GDB/MI command and returns the output as a Python dictionary.
963 ** New function gdb.block_signals(). This returns a context manager
964 that blocks any signals that GDB needs to handle itself.
966 ** New class gdb.Thread. This is a subclass of threading.Thread
967 that calls gdb.block_signals in its "start" method.
969 ** gdb.parse_and_eval now has a new "global_context" parameter.
970 This can be used to request that the parse only examine global
973 ** gdb.Inferior now has a new "arguments" attribute. This holds the
974 command-line arguments to the inferior, if known.
976 ** gdb.Inferior now has a new "main_name" attribute. This holds the
977 name of the inferior's "main", if known.
979 ** gdb.Inferior now has new methods "clear_env", "set_env", and
980 "unset_env". These can be used to modify the inferior's
981 environment before it is started.
983 ** gdb.Value now has the 'assign' method.
985 ** gdb.Value now has the 'to_array' method. This converts an
986 array-like Value to an array.
988 ** gdb.Progspace now has the new method "objfile_for_address". This
989 returns the gdb.Objfile, if any, that covers a given address.
991 ** gdb.Breakpoint now has an "inferior" attribute. If the
992 Breakpoint object is inferior specific then this attribute holds
993 the inferior-id (an integer). If the Breakpoint object is not
994 inferior specific, then this field contains None. This field can
997 ** gdb.Type now has the "is_array_like" and "is_string_like"
998 methods. These reflect GDB's internal idea of whether a type
999 might be array- or string-like, even if they do not have the
1000 corresponding type code.
1002 ** gdb.ValuePrinter is a new class that can be used as the base
1003 class for the result of applying a pretty-printer. As a base
1004 class, it signals to gdb that the printer may implement new
1005 pretty-printer methods.
1007 ** New attribute Progspace.symbol_file. This attribute holds the
1008 gdb.Objfile that corresponds to Progspace.filename (when
1009 Progspace.filename is not None), otherwise, this attribute is
1012 ** New attribute Progspace.executable_filename. This attribute
1013 holds a string containing a file name set by the "exec-file" or
1014 "file" commands, or None if no executable file is set. This
1015 isn't the exact string passed by the user to these commands; the
1016 file name will have been partially resolved to an absolute file
1019 ** A new executable_changed event registry is available. This event
1020 emits ExecutableChangedEvent objects, which have 'progspace' (a
1021 gdb.Progspace) and 'reload' (a Boolean) attributes. This event
1022 is emitted when gdb.Progspace.executable_filename changes.
1024 ** New event registries gdb.events.new_progspace and
1025 gdb.events.free_progspace, these emit NewProgspaceEvent and
1026 FreeProgspaceEvent event types respectively. Both of these event
1027 types have a single 'progspace' attribute, which is the
1028 gdb.Progspace that is either being added to GDB, or removed from
1031 ** gdb.LazyString now implements the __str__ method.
1033 ** New method gdb.Frame.static_link that returns the outer frame
1034 of a nested function frame.
1036 *** Changes in GDB 13
1038 * MI version 1 is deprecated, and will be removed in GDB 14.
1040 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
1041 reading memory tag data for AArch64 MTE from core files generated by
1042 the gcore command or the Linux kernel.
1044 When a process uses memory-mapped pages protected by memory tags (for
1045 example, AArch64 MTE), this additional information will be recorded in
1046 the core file in the event of a crash or if GDB generates a core file
1047 from the current process state. GDB will show this additional information
1048 automatically, or through one of the memory-tag subcommands.
1050 * Scheduler-locking and new threads
1052 When scheduler-locking is in effect, only the current thread may run
1053 when the inferior is resumed. However, previously, new threads
1054 created by the resumed thread would still be able to run free. Now,
1055 they are held stopped.
1057 * "info breakpoints" now displays enabled breakpoint locations of
1058 disabled breakpoints as in the "y-" state. For example:
1060 (gdb) info breakpoints
1061 Num Type Disp Enb Address What
1062 1 breakpoint keep n <MULTIPLE>
1063 1.1 y- 0x00000000000011b6 in ...
1064 1.2 y- 0x00000000000011c2 in ...
1065 1.3 n 0x00000000000011ce in ...
1067 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
1068 aarch64 architectures.
1070 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
1072 * Remove support for building against Python 2, it is now only possible to
1073 build GDB against Python 3.
1075 * DBX mode has been removed.
1077 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
1078 emit to indicate where a breakpoint should be placed to break in a function
1081 * Completion now also offers "NUMBER" for "set" commands that accept
1082 a numeric argument and the "unlimited" keyword. For example:
1084 (gdb) set width <TAB>
1089 (gdb) complete set width
1093 * Disassembler styling using libopcodes. GDB now supports
1094 disassembler styling using libopcodes. This is only available for
1095 some targets (currently x86 and RISC-V). For unsupported targets
1096 Python Pygments is still used. For supported targets, libopcodes
1097 styling is used by default.
1099 * The Windows native target now supports target async.
1101 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
1103 * The format of 'disassemble /r' and 'record instruction-history /r'
1104 has changed. The instruction bytes could now be grouped together,
1105 and displayed in the endianness of the instruction. This is the
1106 same layout as used by GNU objdump when disassembling.
1108 There is now 'disassemble /b' and 'record instruction-history /b'
1109 which will always display the instructions bytes one at a time in
1110 memory order, that is, the byte at the lowest address first.
1112 For both /r and /b GDB is now better at using whitespace in order to
1113 align the disassembled instruction text.
1115 * The TUI no longer styles the source and assembly code highlighted by
1116 the current position indicator by default. You can however
1117 re-enable styling using the new "set style tui-current-position"
1120 * New convenience variable $_inferior_thread_count contains the number
1121 of live threads in the current inferior.
1123 * When a breakpoint with multiple code locations is hit, GDB now prints
1124 the code location using the syntax <breakpoint_number>.<location_number>
1126 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
1128 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
1129 and $_hit_locno to the hit breakpoint number and code location number.
1130 This allows to disable the last hit breakpoint using
1131 (gdb) disable $_hit_bpnum
1132 or disable only the specific breakpoint code location using
1133 (gdb) disable $_hit_bpnum.$_hit_locno
1134 These commands can be used inside the command list of a breakpoint to
1135 automatically disable the just encountered breakpoint (or the just
1136 encountered specific breakpoint code location).
1137 When a breakpoint has only one location, $_hit_locno is set to 1 so that
1138 (gdb) disable $_hit_bpnum.$_hit_locno
1140 (gdb) disable $_hit_bpnum
1141 are both disabling the breakpoint.
1145 maintenance set ignore-prologue-end-flag on|off
1146 maintenance show ignore-prologue-end-flag
1147 This setting, which is off by default, controls whether GDB ignores the
1148 PROLOGUE-END flag from the line-table when skipping prologue. This can be
1149 used to force GDB to use prologue analyzers if the line-table is constructed
1150 from erroneous debug information.
1152 set print nibbles [on|off]
1154 This controls whether the 'print/t' command will display binary values
1155 in groups of four bits, known as "nibbles". The default is 'off'.
1157 maintenance set libopcodes-styling on|off
1158 maintenance show libopcodes-styling
1159 These can be used to force off libopcodes based styling, the Python
1160 Pygments styling will then be used instead.
1162 set style disassembler comment
1163 show style disassembler comment
1164 set style disassembler immediate
1165 show style disassembler immediate
1166 set style disassembler mnemonic
1167 show style disassembler mnemonic
1168 set style disassembler register
1169 show style disassembler register
1170 set style disassembler address
1171 show style disassembler address
1172 set style disassembler symbol
1173 show style disassembler symbol
1174 For targets that support libopcodes based styling, these settings
1175 control how various aspects of the disassembler output are styled.
1176 The 'disassembler address' and 'disassembler symbol' styles are
1177 aliases for the 'address' and 'function' styles respectively.
1179 maintenance print frame-id [ LEVEL ]
1180 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
1181 not given, then print the frame-id for the currently selected frame.
1183 set debug infcall on|off
1185 Print additional debug messages about inferior function calls.
1187 set debug solib on|off
1189 Print additional debug messages about shared library handling.
1191 set style tui-current-position [on|off]
1192 Whether to style the source and assembly code highlighted by the
1193 TUI's current position indicator. The default is off.
1195 set print characters LIMIT
1196 show print characters
1197 This new setting is like 'set print elements', but controls how many
1198 characters of a string are printed. This functionality used to be
1199 covered by 'set print elements', but it can be controlled separately
1200 now. LIMIT can be set to a numerical value to request that particular
1201 character count, to 'unlimited' to print all characters of a string,
1202 or to 'elements', which is also the default, to follow the setting of
1203 'set print elements' as it used to be.
1205 print -characters LIMIT
1206 This new option to the 'print' command has the same effect as a temporary
1207 use of 'set print characters'.
1211 document user-defined
1212 It is now possible to document user-defined aliases.
1213 When a user-defined alias is documented, the help and apropos commands
1214 use the provided documentation instead of the documentation of the
1216 Documenting a user-defined alias is particularly useful when the alias
1217 is a set of nested 'with' commands to avoid showing the help of
1218 the with command for an alias that will in fact launch the
1219 last command given in the nested commands.
1221 maintenance info line-table
1222 Add a PROLOGUE-END column to the output which indicates that an
1223 entry corresponds to an address where a breakpoint should be placed
1224 to be at the first instruction past a function's prologue.
1228 set debug aix-solib on|off
1229 show debug aix-solib
1230 set debug solib-frv on|off
1231 show debug solib-frv
1232 Removed in favor of "set/show debug solib".
1234 maintenance info program-spaces
1235 This command now includes a 'Core File' column which indicates the
1236 name of the core file associated with each program space.
1240 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
1242 GNU/Linux/CSKY (gdbserver) csky*-*linux*
1248 ** The async record stating the stopped reason 'breakpoint-hit' now
1249 contains an optional field locno giving the code location number
1250 when the breakpoint has multiple code locations.
1254 ** GDB will now reformat the doc string for gdb.Command and
1255 gdb.Parameter sub-classes to remove unnecessary leading
1256 whitespace from each line before using the string as the help
1259 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
1260 that formats ADDRESS as 'address <symbol+offset>', where symbol is
1261 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
1262 This is the same format that GDB uses when printing address, symbol,
1263 and offset information from the disassembler.
1265 ** New function gdb.current_language that returns the name of the
1266 current language. Unlike gdb.parameter('language'), this will
1267 never return 'auto'.
1269 ** New method gdb.Frame.language that returns the name of the
1272 ** New Python API for wrapping GDB's disassembler:
1274 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
1275 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
1276 ARCH is either None or a string containing a bfd architecture
1277 name. DISASSEMBLER is registered as a disassembler for
1278 architecture ARCH, or for all architectures if ARCH is None.
1279 The previous disassembler registered for ARCH is returned, this
1280 can be None if no previous disassembler was registered.
1282 - gdb.disassembler.Disassembler is the class from which all
1283 disassemblers should inherit. Its constructor takes a string,
1284 a name for the disassembler, which is currently only used in
1285 some debug output. Sub-classes should override the __call__
1286 method to perform disassembly, invoking __call__ on this base
1287 class will raise an exception.
1289 - gdb.disassembler.DisassembleInfo is the class used to describe
1290 a single disassembly request from GDB. An instance of this
1291 class is passed to the __call__ method of
1292 gdb.disassembler.Disassembler and has the following read-only
1293 attributes: 'address', and 'architecture', as well as the
1294 following method: 'read_memory'.
1296 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
1297 calls GDB's builtin disassembler on INFO, which is a
1298 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
1299 optional, its default value is None. If MEMORY_SOURCE is not
1300 None then it must be an object that has a 'read_memory' method.
1302 - gdb.disassembler.DisassemblerResult is a class that can be used
1303 to wrap the result of a call to a Disassembler. It has
1304 read-only attributes 'length' and 'string'.
1306 ** gdb.Objfile now has an attribute named "is_file". This is True
1307 if the objfile comes from a file, and False otherwise.
1309 ** New function gdb.print_options that returns a dictionary of the
1310 prevailing print options, in the form accepted by
1311 gdb.Value.format_string.
1313 ** gdb.Value.format_string now uses the format provided by 'print',
1314 if it is called during a 'print' or other similar operation.
1316 ** gdb.Value.format_string now accepts the 'summary' keyword. This
1317 can be used to request a shorter representation of a value, the
1318 way that 'set print frame-arguments scalars' does.
1320 ** New Python type gdb.BreakpointLocation.
1321 The new attribute 'locations' of gdb.Breakpoint returns a list of
1322 gdb.BreakpointLocation objects specifying the locations where the
1323 breakpoint is inserted into the debuggee.
1325 ** The gdb.register_window_type method now restricts the set of
1326 acceptable window names. The first character of a window's name
1327 must start with a character in the set [a-zA-Z], every subsequent
1328 character of a window's name must be in the set [-_.a-zA-Z0-9].
1330 * New features in the GDB remote stub, GDBserver
1332 ** GDBserver is now supported on LoongArch GNU/Linux.
1334 ** GDBserver is now supported on CSKY GNU/Linux.
1336 * LoongArch floating-point support
1338 GDB now supports floating-point on LoongArch GNU/Linux.
1340 * AMD GPU ROCm debugging support
1342 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
1345 *** Changes in GDB 12
1347 * DBX mode is deprecated, and will be removed in GDB 13
1349 * GDB 12 is the last release of GDB that will support building against
1350 Python 2. From GDB 13, it will only be possible to build GDB itself
1351 with Python 3 support.
1353 * The disable-randomization setting now works on Windows.
1355 * Improved C++ template support
1357 GDB now treats functions/types involving C++ templates like it does function
1358 overloads. Users may omit parameter lists to set breakpoints on families of
1359 template functions, including types/functions composed of multiple template types:
1361 (gdb) break template_func(template_1, int)
1363 The above will set breakpoints at every function `template_func' where
1364 the first function parameter is any template type named `template_1' and
1365 the second function parameter is `int'.
1367 TAB completion also gains similar improvements.
1369 * The FreeBSD native target now supports async mode.
1375 Enable or disable multithreaded symbol loading. This is enabled
1376 by default, but passing --disable-threading or --enable-threading=no
1377 to configure will disable it.
1379 Disabling this can cause a performance penalty when there are a lot of
1380 symbols to load, but is useful for debugging purposes.
1384 maint set backtrace-on-fatal-signal on|off
1385 maint show backtrace-on-fatal-signal
1386 This setting is 'on' by default. When 'on' GDB will print a limited
1387 backtrace to stderr in the situation where GDB terminates with a
1388 fatal signal. This only supported on some platforms where the
1389 backtrace and backtrace_symbols_fd functions are available.
1391 set source open on|off
1393 This setting, which is on by default, controls whether GDB will try
1394 to open source code files. Switching this off will stop GDB trying
1395 to open and read source code files, which can be useful if the files
1396 are located over a slow network connection.
1400 These are now deprecated aliases for "set max-value-size" and
1401 "show max-value-size".
1403 task apply [all | TASK-IDS...] [FLAG]... COMMAND
1404 Like "thread apply", but applies COMMAND to Ada tasks.
1407 Watchpoints can now be restricted to a specific Ada task.
1409 maint set internal-error backtrace on|off
1410 maint show internal-error backtrace
1411 maint set internal-warning backtrace on|off
1412 maint show internal-warning backtrace
1413 GDB can now print a backtrace of itself when it encounters either an
1414 internal-error, or an internal-warning. This is on by default for
1415 internal-error and off by default for internal-warning.
1418 Deprecated and replaced by "set logging enabled on|off".
1420 set logging enabled on|off
1421 show logging enabled
1422 These commands set or show whether logging is enabled or disabled.
1425 You can now exit GDB by using the new command "exit", in addition to
1426 the existing "quit" command.
1428 set debug threads on|off
1430 Print additional debug messages about thread creation and deletion.
1432 set debug linux-nat on|off
1433 show debug linux-nat
1434 These new commands replaced the old 'set debug lin-lwp' and 'show
1435 debug lin-lwp' respectively. Turning this setting on prints debug
1436 messages relating to GDB's handling of native Linux inferiors.
1438 maint flush source-cache
1439 Flush the contents of the source code cache.
1441 maint set gnu-source-highlight enabled on|off
1442 maint show gnu-source-highlight enabled
1443 Whether GDB should use the GNU Source Highlight library for adding
1444 styling to source code. When off, the library will not be used, even
1445 when available. When GNU Source Highlight isn't used, or can't add
1446 styling to a particular source file, then the Python Pygments
1447 library will be used instead.
1449 set suppress-cli-notifications (on|off)
1450 show suppress-cli-notifications
1451 This controls whether printing the notifications is suppressed for CLI.
1452 CLI notifications occur when you change the selected context
1453 (i.e., the current inferior, thread and/or the frame), or when
1454 the program being debugged stops (e.g., because of hitting a
1455 breakpoint, completing source-stepping, an interrupt, etc.).
1457 set style disassembler enabled on|off
1458 show style disassembler enabled
1459 If GDB is compiled with Python support, and the Python Pygments
1460 package is available, then, when this setting is on, disassembler
1461 output will have styling applied.
1463 set ada source-charset
1464 show ada source-charset
1465 Set the character set encoding that is assumed for Ada symbols. Valid
1466 values for this follow the values that can be passed to the GNAT
1467 compiler via the '-gnati' option. The default is ISO-8859-1.
1473 These are the new names for the old 'layout', 'focus', 'refresh',
1474 and 'winheight' tui commands respectively. The old names still
1475 exist as aliases to these new commands.
1479 The new command 'tui window width', and the alias 'winwidth' allow
1480 the width of a tui window to be adjusted when windows are laid out
1483 set debug tui on|off
1485 Control the display of debug output about GDB's tui.
1490 Printing of floating-point values with base-modifying formats like
1491 /x has been changed to display the underlying bytes of the value in
1492 the desired base. This was GDB's documented behavior, but was never
1493 implemented correctly.
1496 This command can now print a reply, if the reply includes
1497 non-printable characters. Any non-printable characters are printed
1498 as escaped hex, e.g. \x?? where '??' is replaces with the value of
1499 the non-printable character.
1502 The clone-inferior command now ensures that the TTY, CMD and ARGS
1503 settings are copied from the original inferior to the new one.
1504 All modifications to the environment variables done using the 'set
1505 environment' or 'unset environment' commands are also copied to the new
1508 set debug lin-lwp on|off
1510 These commands have been removed from GDB. The new command 'set
1511 debug linux-nat' and 'show debug linux-nat' should be used
1515 This command now includes information about the width of the tui
1516 windows in its output.
1522 These commands are now aliases for the 'tui layout', 'tui focus',
1523 'tui refresh', and 'tui window height' commands respectively.
1525 * GDB's Ada parser now supports an extension for specifying the exact
1526 byte contents of a floating-point literal. This can be useful for
1527 setting floating-point registers to a precise value without loss of
1528 precision. The syntax is an extension of the based literal syntax.
1529 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
1530 of the floating-point type, and the "f" is the marker for floating
1535 ** The '-add-inferior' with no option flags now inherits the
1536 connection of the current inferior, this restores the behavior of
1537 GDB as it was prior to GDB 10.
1539 ** The '-add-inferior' command now accepts a '--no-connection'
1540 option, which causes the new inferior to start without a
1543 ** The default version of the MI interpreter is now 4 (-i=mi4).
1545 ** The "script" field in breakpoint output (which is syntactically
1546 incorrect in MI 3 and below) has changed in MI 4 to become a list.
1547 This affects the following commands and events:
1551 - =breakpoint-created
1552 - =breakpoint-modified
1554 The -fix-breakpoint-script-output command can be used to enable
1555 this behavior with previous MI versions.
1559 GNU/Linux/LoongArch loongarch*-*-linux*
1567 ** New function gdb.add_history(), which takes a gdb.Value object
1568 and adds the value it represents to GDB's history list. An
1569 integer, the index of the new item in the history list, is
1572 ** New function gdb.history_count(), which returns the number of
1573 values in GDB's value history.
1575 ** New gdb.events.gdb_exiting event. This event is called with a
1576 gdb.GdbExitingEvent object which has the read-only attribute
1577 'exit_code', which contains the value of the GDB exit code. This
1578 event is triggered once GDB decides it is going to exit, but
1579 before GDB starts to clean up its internal state.
1581 ** New function gdb.architecture_names(), which returns a list
1582 containing all of the possible Architecture.name() values. Each
1585 ** New function gdb.Architecture.integer_type(), which returns an
1586 integer type given a size and a signed-ness.
1588 ** New gdb.TargetConnection object type that represents a connection
1589 (as displayed by the 'info connections' command). A sub-class,
1590 gdb.RemoteTargetConnection, is used to represent 'remote' and
1591 'extended-remote' connections.
1593 ** The gdb.Inferior type now has a 'connection' property which is an
1594 instance of gdb.TargetConnection, the connection used by this
1595 inferior. This can be None if the inferior has no connection.
1597 ** New 'gdb.events.connection_removed' event registry, which emits a
1598 'gdb.ConnectionEvent' when a connection is removed from GDB.
1599 This event has a 'connection' property, a gdb.TargetConnection
1600 object for the connection being removed.
1602 ** New gdb.connections() function that returns a list of all
1603 currently active connections.
1605 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
1606 is equivalent to the existing 'maint packet' CLI command; it
1607 allows a user specified packet to be sent to the remote target.
1609 ** New function gdb.host_charset(), returns a string, which is the
1610 name of the current host charset.
1612 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
1615 ** New gdb.with_parameter(NAME, VALUE). This returns a context
1616 manager that temporarily sets the gdb parameter NAME to VALUE,
1617 then resets it when the context is exited.
1619 ** The gdb.Value.format_string method now takes a 'styling'
1620 argument, which is a boolean. When true, the returned string can
1621 include escape sequences to apply styling. The styling will only
1622 be present if styling is otherwise turned on in GDB (see 'help
1623 set styling'). When false, which is the default if the argument
1624 is not given, then no styling is applied to the returned string.
1626 ** New read-only attribute gdb.InferiorThread.details, which is
1627 either a string, containing additional, target specific thread
1628 state information, or None, if there is no such additional
1631 ** New read-only attribute gdb.Type.is_scalar, which is True for
1632 scalar types, and False for all other types.
1634 ** New read-only attribute gdb.Type.is_signed. This attribute
1635 should only be read when Type.is_scalar is True, and will be True
1636 for signed types, and False for all other types. Attempting to
1637 read this attribute for non-scalar types will raise a ValueError.
1639 ** It is now possible to add GDB/MI commands implemented in Python.
1641 * New features in the GDB remote stub, GDBserver
1643 ** GDBserver is now supported on OpenRISC GNU/Linux.
1645 * New native configurations
1647 GNU/Linux/OpenRISC or1k*-*-linux*
1649 *** Changes in GDB 11
1651 * The 'set disassembler-options' command now supports specifying options
1654 * GDB now supports general memory tagging functionality if the underlying
1655 architecture supports the proper primitives and hooks. Currently this is
1656 enabled only for AArch64 MTE.
1660 - Additional information when the inferior crashes with a SIGSEGV caused by
1661 a memory tag violation.
1663 - A new modifier 'm' for the "x" command, which displays allocation tags for a
1664 particular memory range.
1666 - Display of memory tag mismatches by "print", for addresses and
1667 pointers, if memory tagging is supported by the architecture.
1669 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
1674 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
1676 The MI -break-insert and -dprintf-insert commands now support a
1677 new "--qualified" option that makes GDB interpret a specified
1678 function name as a complete fully-qualified name. This is the
1679 equivalent of the CLI's "break -qualified" and "dprintf
1682 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
1684 The MI -break-insert and -dprintf-insert commands now support a
1685 '--force-condition' flag to forcibly define a condition even when
1686 the condition is invalid at all locations of the breakpoint. This
1687 is equivalent to the '-force-condition' flag of the CLI's "break"
1690 ** '-break-condition --force'
1692 The MI -break-condition command now supports a '--force' flag to
1693 forcibly define a condition even when the condition is invalid at
1694 all locations of the selected breakpoint. This is equivalent to
1695 the '-force' flag of the CLI's "cond" command.
1697 ** '-file-list-exec-source-files [--group-by-objfile]
1698 [--basename | --dirname]
1701 The existing -file-list-exec-source-files command now takes an
1702 optional REGEXP which is used to filter the source files that are
1703 included in the results.
1705 By default REGEXP is matched against the full filename of the
1706 source file. When one of --basename or --dirname is given then
1707 REGEXP is only matched against the specified part of the full
1710 When the optional --group-by-objfile flag is used the output
1711 format is changed, the results are now a list of object files
1712 (executable and libraries) with the source files that are
1713 associated with each object file.
1715 The results from -file-list-exec-source-files now include a
1716 'debug-fully-read' field which takes the value 'true' or 'false'.
1717 A 'true' value indicates the source file is from a compilation
1718 unit that has had its debug information fully read in by GDB, a
1719 value of 'false' indicates GDB has only performed a partial scan
1720 of the debug information so far.
1722 * GDB now supports core file debugging for x86_64 Cygwin programs.
1724 * GDB will now look for the .gdbinit file in a config directory before
1725 looking for ~/.gdbinit. The file is searched for in the following
1726 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
1727 $HOME/.gdbinit. On Apple hosts the search order is instead:
1728 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
1730 * GDB now supports fixed point types which are described in DWARF
1731 as base types with a fixed-point encoding. Additionally, support
1732 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
1735 For Ada, this allows support for fixed point types without requiring
1736 the use of the GNAT encoding (based on information added to the type's
1737 name following a GNAT-specific format).
1739 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
1740 or ~/.gdbearlyinit if these files are present. These files are
1741 processed earlier than any of the other initialization files and
1742 can affect parts of GDB's startup that previously had already been
1743 completed before the initialization files were read, for example
1744 styling of the initial GDB greeting.
1746 * GDB now has two new options "--early-init-command" and
1747 "--early-init-eval-command" with corresponding short options "-eix"
1748 and "-eiex" that allow options (that would normally appear in a
1749 gdbearlyinit file) to be passed on the command line.
1751 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
1752 now understood by GDB, and can be used to describe the vector
1753 registers of a target. The precise requirements of this register
1754 feature are documented in the GDB manual.
1756 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
1757 supported by GDB and describes a new VPR register from the ARM MVE
1758 (Helium) extension. See the GDB manual for more information.
1762 ** TUI windows now support mouse actions. The mouse wheel scrolls
1763 the appropriate window.
1765 ** Key combinations that do not have a specific action on the
1766 focused window are passed to GDB. For example, you now can use
1767 Ctrl-Left/Ctrl-Right to move between words in the command window
1768 regardless of which window is in focus. Previously you would
1769 need to focus on the command window for such key combinations to
1774 set debug event-loop
1775 show debug event-loop
1776 Control the display of debug output about GDB's event loop.
1778 set print memory-tag-violations
1779 show print memory-tag-violations
1780 Control whether to display additional information about memory tag violations
1781 when printing pointers and addresses. Architecture support for memory
1782 tagging is required for this option to have an effect.
1784 maintenance flush symbol-cache
1785 maintenance flush register-cache
1786 These new commands are equivalent to the already existing commands
1787 'maintenance flush-symbol-cache' and 'flushregs' respectively.
1789 maintenance flush dcache
1790 A new command to flush the dcache.
1792 maintenance info target-sections
1793 Print GDB's internal target sections table.
1795 maintenance info jit
1796 Print the JIT code objects in the inferior known to GDB.
1798 memory-tag show-logical-tag POINTER
1799 Print the logical tag for POINTER.
1800 memory-tag with-logical-tag POINTER TAG
1801 Print POINTER with logical tag TAG.
1802 memory-tag show-allocation-tag ADDRESS
1803 Print the allocation tag for ADDRESS.
1804 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1805 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1806 memory-tag check POINTER
1807 Validate that POINTER's logical tag matches the allocation tag.
1809 set startup-quietly on|off
1810 show startup-quietly
1811 When 'on', this causes GDB to act as if "-silent" were passed on the
1812 command line. This command needs to be added to an early
1813 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1816 set print type hex on|off
1818 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1819 and offsets of struct members. When 'off', decimal notation is used.
1821 set python ignore-environment on|off
1822 show python ignore-environment
1823 When 'on', this causes GDB's builtin Python to ignore any
1824 environment variables that would otherwise affect how Python
1825 behaves. This command needs to be added to an early initialization
1826 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1828 set python dont-write-bytecode auto|on|off
1829 show python dont-write-bytecode
1830 When 'on', this causes GDB's builtin Python to not write any
1831 byte-code (.pyc files) to disk. This command needs to be added to
1832 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1833 order to affect GDB. When 'off' byte-code will always be written.
1834 When set to 'auto' (the default) Python will check the
1835 PYTHONDONTWRITEBYTECODE environment variable.
1839 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1840 [-force-condition] [if CONDITION]
1841 This command would previously refuse setting a breakpoint if the
1842 CONDITION expression is invalid at a location. It now accepts and
1843 defines the breakpoint if there is at least one location at which
1844 the CONDITION is valid. The locations for which the CONDITION is
1845 invalid, are automatically disabled. If CONDITION is invalid at all
1846 of the locations, setting the breakpoint is still rejected. However,
1847 the '-force-condition' flag can be used in this case for forcing GDB to
1848 define the breakpoint, making all the current locations automatically
1849 disabled. This may be useful if the user knows the condition will
1850 become meaningful at a future location, e.g. due to a shared library
1853 condition [-force] N COND
1854 The behavior of this command is changed the same way for the 'break'
1855 command as explained above. The '-force' flag can be used to force
1856 GDB into defining the condition even when COND is invalid for all the
1857 current locations of breakpoint N.
1860 maintenance flush-symbol-cache
1861 These commands are deprecated in favor of the new commands
1862 'maintenance flush register-cache' and 'maintenance flush
1863 symbol-cache' respectively.
1865 set style version foreground COLOR
1866 set style version background COLOR
1867 set style version intensity VALUE
1868 Control the styling of GDB's version number text.
1871 When the ID parameter is omitted, then this command prints information
1872 about the current inferior. When the ID parameter is present, the
1873 behavior of the command is unchanged and have the inferior ID become
1874 the current inferior.
1876 maintenance info sections
1877 The ALLOBJ keyword has been replaced with an -all-objects command
1878 line flag. It is now possible to filter which sections are printed
1879 even when -all-objects is passed.
1881 ptype[/FLAGS] TYPE | EXPRESSION
1882 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
1883 notation is used when printing sizes and offsets of struct members.
1884 When '/d' is set, decimal notation is used when printing sizes and
1885 offsets of struct members. Default behavior is given by 'show print
1889 The info sources command output has been restructured. The results
1890 are now based around a list of objfiles (executable and libraries),
1891 and for each objfile the source files that are part of that objfile
1894 * Removed targets and native configurations
1896 ARM Symbian arm*-*-symbianelf*
1898 * New remote packets
1901 Request the remote to send allocation tags for a particular memory range.
1903 Request the remote to store the specified allocation tags to the requested
1908 ** Improved support for rvalue reference values:
1909 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1910 value-referenced-value procedure now handles rvalue reference
1913 ** New procedures for obtaining value variants:
1914 value-reference-value, value-rvalue-reference-value and
1917 ** Temporary breakpoints can now be created with make-breakpoint and
1918 tested for using breakpoint-temporary?.
1922 ** Inferior objects now contain a read-only 'connection_num' attribute that
1923 gives the connection number as seen in 'info connections' and
1926 ** New method gdb.Frame.level() which returns the stack level of the
1929 ** New method gdb.PendingFrame.level() which returns the stack level
1930 of the frame object.
1932 ** When hitting a catchpoint, the Python API will now emit a
1933 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1934 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1936 ** Python TUI windows can now receive mouse click events. If the
1937 Window object implements the click method, it is called for each
1938 mouse click event in this window.
1940 *** Changes in GDB 10
1942 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1943 and "org.gnu.gdb.arc.aux". The old names are still supported but
1944 must be considered obsolete. They will be deprecated after some
1947 * Help and apropos commands will now show the documentation of a
1948 command only once, even if that command has one or more aliases.
1949 These commands now show the command name, then all of its aliases,
1950 and finally the description of the command.
1952 * 'help aliases' now shows only the user defined aliases. GDB predefined
1953 aliases are shown together with their aliased command.
1955 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1956 debugging information as well as source code.
1958 When built with debuginfod, GDB can automatically query debuginfod
1959 servers for the separate debug files and source code of the executable
1962 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1963 requires libdebuginfod, the debuginfod client library).
1965 debuginfod is distributed with elfutils, starting with version 0.178.
1967 You can get the latest version from https://sourceware.org/elfutils.
1969 * Multi-target debugging support
1971 GDB now supports debugging multiple target connections
1972 simultaneously. For example, you can now have each inferior
1973 connected to different remote servers running in different machines,
1974 or have one inferior debugging a local native process, an inferior
1975 debugging a core dump, etc.
1977 This support is experimental and comes with some limitations -- you
1978 can only resume multiple targets simultaneously if all targets
1979 support non-stop mode, and all remote stubs or servers must support
1980 the same set of remote protocol features exactly. See also "info
1981 connections" and "add-inferior -no-connection" below, and "maint set
1982 target-non-stop" in the user manual.
1984 * New features in the GDB remote stub, GDBserver
1986 ** GDBserver is now supported on ARC GNU/Linux.
1988 ** GDBserver is now supported on RISC-V GNU/Linux.
1990 ** GDBserver no longer supports these host triplets:
1992 i[34567]86-*-lynxos*
2001 i[34567]86-*-mingw32ce*
2003 * Debugging MS-Windows processes now sets $_exitsignal when the
2004 inferior is terminated by a signal, instead of setting $_exitcode.
2006 * Multithreaded symbol loading has now been enabled by default on systems
2007 that support it (see entry for GDB 9, below), providing faster
2008 performance for programs with many symbols.
2010 * The $_siginfo convenience variable now also works on Windows targets,
2011 and will display the EXCEPTION_RECORD of the last handled exception.
2013 * TUI windows can now be arranged horizontally.
2015 * The command history filename can now be set to the empty string
2016 either using 'set history filename' or by setting 'GDBHISTFILE=' in
2017 the environment. The effect of setting this filename to the empty
2018 string is that GDB will not try to load any previous command
2021 * On Windows targets, it is now possible to debug 32-bit programs with a
2026 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
2027 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
2028 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
2029 running process, this new option indicates whether to detect
2030 a mismatch between the current executable file loaded by GDB and the
2031 executable file used to start the process. If 'ask', the default,
2032 display a warning and ask the user whether to load the process
2033 executable file; if 'warn', just display a warning; if 'off', don't
2034 attempt to detect a mismatch.
2036 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
2037 Define a new TUI layout, specifying its name and the windows that
2040 maintenance print xml-tdesc [FILE]
2041 Prints the current target description as an XML document. If the
2042 optional FILE is provided (which is an XML target description) then
2043 the target description is read from FILE into GDB, and then
2046 maintenance print core-file-backed-mappings
2047 Prints file-backed mappings loaded from a core file's note section.
2048 Output is expected to be similar to that of "info proc mappings".
2050 set debug fortran-array-slicing on|off
2051 show debug fortran-array-slicing
2052 Print debugging when taking slices of Fortran arrays.
2054 set fortran repack-array-slices on|off
2055 show fortran repack-array-slices
2056 When taking slices from Fortran arrays and strings, if the slice is
2057 non-contiguous within the original value then, when this option is
2058 on, the new value will be repacked into a single contiguous value.
2059 When this option is off, then the value returned will consist of a
2060 descriptor that describes the slice within the memory of the
2061 original parent value.
2065 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
2066 The alias command can now specify default args for an alias.
2067 GDB automatically prepends the alias default args to the argument list
2068 provided explicitly by the user.
2069 For example, to have a backtrace with full details, you can define
2070 an alias 'bt_ALL' as
2071 'alias bt_ALL = backtrace -entry-values both -frame-arg all
2072 -past-main -past-entry -full'.
2073 Alias default arguments can also use a set of nested 'with' commands,
2074 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
2075 defines the alias pp10 that will pretty print a maximum of 10 elements
2076 of the given expression (if the expression is an array).
2080 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
2081 BPF bpf-unknown-none
2086 ** gdb.register_window_type can be used to implement new TUI windows
2089 ** Dynamic types can now be queried. gdb.Type has a new attribute,
2090 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
2091 field of a dynamic type may have None for its "bitpos" attribute
2094 ** Commands written in Python can be in the "TUI" help class by
2095 registering with the new constant gdb.COMMAND_TUI.
2097 ** New method gdb.PendingFrame.architecture () to retrieve the
2098 architecture of the pending frame.
2100 ** New gdb.Architecture.registers method that returns a
2101 gdb.RegisterDescriptorIterator object, an iterator that returns
2102 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
2103 way to query the registers available for an architecture.
2105 ** New gdb.Architecture.register_groups method that returns a
2106 gdb.RegisterGroupIterator object, an iterator that returns
2107 gdb.RegisterGroup objects. The new RegisterGroup is a way to
2108 discover the available register groups.
2112 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
2114 ** Procedures 'memory-port-read-buffer-size',
2115 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
2116 and 'set-memory-port-write-buffer-size!' are deprecated. When
2117 using Guile 2.2 and later, users who need to control the size of
2118 a memory port's internal buffer can use the 'setvbuf' procedure.
2120 *** Changes in GDB 9
2122 * 'thread-exited' event is now available in the annotations interface.
2124 * New built-in convenience variables $_gdb_major and $_gdb_minor
2125 provide the GDB version. They are handy for conditionally using
2126 features available only in or since specific GDB versions, in
2127 scripts that should work error-free with many different versions,
2128 such as in system-wide init files.
2130 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
2131 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
2132 of the GDB settings and the GDB maintenance settings. They are handy
2133 for changing the logic of user defined commands depending on the
2134 current GDB settings.
2136 * GDB now supports Thread Local Storage (TLS) variables on several
2137 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
2138 architectures require kernel changes. TLS is not yet supported for
2139 amd64 and i386 process core dumps.
2141 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
2142 addresses that required unmasking are shown in the backtrace with the
2145 * Two new convenience functions $_cimag and $_creal that extract the
2146 imaginary and real parts respectively from complex numbers.
2148 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
2149 provide the exitcode or exit status of the shell commands launched by
2150 GDB commands such as "shell", "pipe" and "make".
2152 * The command define-prefix can now define user defined prefix commands.
2153 User defined commands can now be defined using these user defined prefix
2156 * Command names can now use the . character.
2158 * The RX port now supports XML target descriptions.
2160 * GDB now shows the Ada task names at more places, e.g. in task switching
2163 * GDB can now be compiled with Python 3 on Windows.
2165 * New convenience variable $_ada_exception holds the address of the
2166 Ada exception being thrown. This is set by Ada-related catchpoints.
2168 * GDB can now place breakpoints on nested functions and subroutines in
2169 Fortran code. The '::' operator can be used between parent and
2170 child scopes when placing breakpoints, for example:
2172 (gdb) break outer_function::inner_function
2174 The 'outer_function::' prefix is only needed if 'inner_function' is
2175 not visible in the current scope.
2177 * In addition to the system-wide gdbinit file, if configured with
2178 --with-system-gdbinit-dir, GDB will now also load files in that directory
2179 as system gdbinit files, unless the -nx or -n flag is provided. Files
2180 with extensions .gdb, .py and .scm are supported as long as GDB was
2181 compiled with support for that language.
2183 * GDB now supports multithreaded symbol loading for higher performance.
2184 This feature is still in testing, so it is disabled by default. You
2185 can turn it on using 'maint set worker-threads unlimited'.
2189 ** The gdb.Value type has a new method 'format_string' which returns a
2190 string representing the value. The formatting is controlled by the
2191 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
2192 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
2193 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
2195 ** gdb.Type has a new property 'objfile' which returns the objfile the
2196 type was defined in.
2198 ** The frame information printed by the python frame filtering code
2199 is now consistent with what the 'backtrace' command prints when
2200 there are no filters, or when the 'backtrace' '-no-filters' option
2203 ** The new function gdb.lookup_static_symbol can be used to look up
2204 symbols with static linkage.
2206 ** The new function gdb.lookup_static_symbols can be used to look up
2207 all static symbols with static linkage.
2209 ** gdb.Objfile has new methods 'lookup_global_symbol' and
2210 'lookup_static_symbol' to lookup a symbol from this objfile only.
2212 ** gdb.Block now supports the dictionary syntax for accessing symbols in
2213 this block (e.g. block['local_variable']).
2217 | [COMMAND] | SHELL_COMMAND
2218 | -d DELIM COMMAND DELIM SHELL_COMMAND
2219 pipe [COMMAND] | SHELL_COMMAND
2220 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
2221 Executes COMMAND and sends its output to SHELL_COMMAND.
2222 With no COMMAND, repeat the last executed command
2223 and send its output to SHELL_COMMAND.
2225 define-prefix COMMAND
2226 Define or mark a command as a user-defined prefix command.
2228 with SETTING [VALUE] [-- COMMAND]
2229 w SETTING [VALUE] [-- COMMAND]
2230 Temporarily set SETTING, run COMMAND, and restore SETTING.
2231 Usage: with SETTING -- COMMAND
2232 With no COMMAND, repeats the last executed command.
2233 SETTING is any GDB setting you can change with the "set"
2234 subcommands. For example, 'with language c -- print someobj'
2235 temporarily switches to the C language in order to print someobj.
2236 Settings can be combined: 'w lang c -- w print elements unlimited --
2237 usercmd' switches to the C language and runs usercmd with no limit
2238 of array elements to print.
2240 maint with SETTING [VALUE] [-- COMMAND]
2241 Like "with", but works with "maintenance set" settings.
2243 set may-call-functions [on|off]
2244 show may-call-functions
2245 This controls whether GDB will attempt to call functions in
2246 the program, such as with expressions in the print command. It
2247 defaults to on. Calling functions in the program being debugged
2248 can have undesired side effects. It is now possible to forbid
2249 such function calls. If function calls are forbidden, GDB will throw
2250 an error when a command (such as print expression) calls a function
2253 set print finish [on|off]
2255 This controls whether the `finish' command will display the value
2256 that is returned by the current function. When `off', the value is
2257 still entered into the value history, but it is not printed. The
2261 show print max-depth
2262 Allows deeply nested structures to be simplified when printing by
2263 replacing deeply nested parts (beyond the max-depth) with ellipses.
2264 The default max-depth is 20, but this can be set to unlimited to get
2265 the old behavior back.
2267 set print raw-values [on|off]
2268 show print raw-values
2269 By default, GDB applies the enabled pretty printers when printing a
2270 value. This allows to ignore the enabled pretty printers for a series
2271 of commands. The default is 'off'.
2273 set logging debugredirect [on|off]
2274 By default, GDB debug output will go to both the terminal and the logfile.
2275 Set if you want debug output to go only to the log file.
2277 set style title foreground COLOR
2278 set style title background COLOR
2279 set style title intensity VALUE
2280 Control the styling of titles.
2282 set style highlight foreground COLOR
2283 set style highlight background COLOR
2284 set style highlight intensity VALUE
2285 Control the styling of highlightings.
2287 maint set worker-threads
2288 maint show worker-threads
2289 Control the number of worker threads that can be used by GDB. The
2290 default is 0. "unlimited" lets GDB choose a number that is
2291 reasonable. Currently worker threads are only used when demangling
2292 the names of linker symbols.
2294 set style tui-border foreground COLOR
2295 set style tui-border background COLOR
2296 Control the styling of TUI borders.
2298 set style tui-active-border foreground COLOR
2299 set style tui-active-border background COLOR
2300 Control the styling of the active TUI border.
2302 maint set test-settings KIND
2303 maint show test-settings KIND
2304 A set of commands used by the testsuite for exercising the settings
2307 maint set tui-resize-message [on|off]
2308 maint show tui-resize-message
2309 Control whether GDB prints a message each time the terminal is
2310 resized when in TUI mode. This is primarily useful for testing the
2313 set print frame-info [short-location|location|location-and-address
2314 |source-and-location|source-line|auto]
2315 show print frame-info
2316 This controls what frame information is printed by the commands printing
2317 a frame. This setting will e.g. influence the behavior of 'backtrace',
2318 'frame', 'stepi'. The python frame filtering also respect this setting.
2319 The 'backtrace' '-frame-info' option can override this global setting.
2321 set tui compact-source
2322 show tui compact-source
2324 Enable the "compact" display mode for the TUI source window. The
2325 compact display uses only as much space as is needed for the line
2326 numbers in the current file, and only a single space to separate the
2327 line numbers from the source.
2329 info modules [-q] [REGEXP]
2330 Return a list of Fortran modules matching REGEXP, or all modules if
2333 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
2334 Return a list of functions within all modules, grouped by module.
2335 The list of functions can be restricted with the optional regular
2336 expressions. MODULE_REGEXP matches against the module name,
2337 TYPE_REGEXP matches against the function type signature, and REGEXP
2338 matches against the function name.
2340 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
2341 Return a list of variables within all modules, grouped by module.
2342 The list of variables can be restricted with the optional regular
2343 expressions. MODULE_REGEXP matches against the module name,
2344 TYPE_REGEXP matches against the variable type, and REGEXP matches
2345 against the variable name.
2347 set debug remote-packet-max-chars
2348 show debug remote-packet-max-chars
2349 Controls the number of characters to output in a remote packet when using
2351 The default is 512 bytes.
2354 Lists the target connections currently in use.
2359 The "help" command uses the title style to enhance the
2360 readability of its output by styling the classes and
2364 Similarly to "help", the "apropos" command also uses the
2365 title style for the command names. "apropos" accepts now
2366 a flag "-v" (verbose) to show the full documentation
2367 of matching commands and to use the highlight style to mark
2368 the documentation parts matching REGEXP.
2372 The GDB printf and eval commands can now print C-style and Ada-style
2373 string convenience variables without calling functions in the program.
2374 This allows to do formatted printing of strings without having
2375 a running inferior, or when debugging a core dump.
2377 info sources [-dirname | -basename] [--] [REGEXP]
2378 This command has now optional arguments to only print the files
2379 whose names match REGEXP. The arguments -dirname and -basename
2380 allow to restrict matching respectively to the dirname and basename
2384 The "show style" and its subcommands are now styling
2385 a style name in their output using its own style, to help
2386 the user visualize the different styles.
2388 set print frame-arguments
2389 The new value 'presence' indicates to only indicate the presence of
2390 arguments using ..., instead of printing argument names and values.
2392 set print raw-frame-arguments
2393 show print raw-frame-arguments
2395 These commands replace the similarly-named "set/show print raw
2396 frame-arguments" commands (now with a dash instead of a space). The
2397 old commands are now deprecated and may be removed in a future
2400 add-inferior [-no-connection]
2401 The add-inferior command now supports a "-no-connection" flag that
2402 makes the new inferior start with no target connection associated.
2403 By default, the new inferior inherits the target connection of the
2404 current inferior. See also "info connections".
2407 This command's output now includes a new "Connection" column
2408 indicating which target connection an inferior is bound to. See
2409 "info connections" above.
2411 maint test-options require-delimiter
2412 maint test-options unknown-is-error
2413 maint test-options unknown-is-operand
2414 maint show test-options-completion-result
2415 Commands used by the testsuite to validate the command options
2418 focus, winheight, +, -, >, <
2419 These commands are now case-sensitive.
2421 * New command options, command completion
2423 GDB now has a standard infrastructure to support dash-style command
2424 options ('-OPT'). One benefit is that commands that use it can
2425 easily support completion of command line arguments. Try "CMD
2426 -[TAB]" or "help CMD" to find options supported by a command. Over
2427 time, we intend to migrate most commands to this infrastructure. A
2428 number of commands got support for new command options in this
2431 ** The "print" and "compile print" commands now support a number of
2432 options that allow overriding relevant global print settings as
2433 set by "set print" subcommands:
2437 -array-indexes [on|off]
2438 -elements NUMBER|unlimited
2442 -raw-values [on|off]
2443 -repeats NUMBER|unlimited
2444 -static-members [on|off]
2449 Note that because the "print"/"compile print" commands accept
2450 arbitrary expressions which may look like options (including
2451 abbreviations), if you specify any command option, then you must
2452 use a double dash ("--") to mark the end of argument processing.
2454 ** The "backtrace" command now supports a number of options that
2455 allow overriding relevant global print settings as set by "set
2456 backtrace" and "set print" subcommands:
2458 -entry-values no|only|preferred|if-needed|both|compact|default
2459 -frame-arguments all|scalars|none
2460 -raw-frame-arguments [on|off]
2461 -frame-info auto|source-line|location|source-and-location
2462 |location-and-address|short-location
2464 -past-entry [on|off]
2466 In addition, the full/no-filters/hide qualifiers are now also
2467 exposed as command options too:
2473 ** The "frame apply", "tfaas" and "faas" commands similarly now
2474 support the following options:
2477 -past-entry [on|off]
2479 ** The new "info sources" options -dirname and -basename options
2480 are using the standard '-OPT' infrastructure.
2482 All options above can also be abbreviated. The argument of boolean
2483 (on/off) options can be 0/1 too, and also the argument is assumed
2484 "on" if omitted. This allows writing compact command invocations,
2487 (gdb) p -ra -p -o 0 -- *myptr
2489 The above is equivalent to:
2491 (gdb) print -raw-values -pretty -object off -- *myptr
2493 ** The "info types" command now supports the '-q' flag to disable
2494 printing of some header information in a similar fashion to "info
2495 variables" and "info functions".
2497 ** The "info variables", "info functions", and "whereis" commands
2498 now take a '-n' flag that excludes non-debug symbols (symbols
2499 from the symbol table, not from the debug info such as DWARF)
2502 * Completion improvements
2504 ** GDB can now complete the options of the "thread apply all" and
2505 "taas" commands, and their "-ascending" option can now be
2508 ** GDB can now complete the options of the "info threads", "info
2509 functions", "info variables", "info locals", and "info args"
2512 ** GDB can now complete the options of the "compile file" and
2513 "compile code" commands. The "compile file" command now
2514 completes on filenames.
2516 ** GDB can now complete the backtrace command's
2517 "full/no-filters/hide" qualifiers.
2519 * In settings, you can now abbreviate "unlimited".
2521 E.g., "set print elements u" is now equivalent to "set print
2522 elements unlimited".
2527 This lists all the possible completions for the rest of the line, if it
2528 were to be given as a command itself. This is intended for use by MI
2529 frontends in cases when separate CLI and MI channels cannot be used.
2531 -catch-throw, -catch-rethrow, and -catch-catch
2532 These can be used to catch C++ exceptions in a similar fashion to
2533 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
2535 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
2536 These commands are the MI equivalent of the CLI commands 'info
2537 functions', 'info types', and 'info variables' respectively.
2539 -symbol-info-modules, this is the MI equivalent of the CLI 'info
2542 -symbol-info-module-functions and -symbol-info-module-variables.
2543 These commands are the MI equivalent of the CLI commands 'info
2544 module functions' and 'info module variables'.
2548 ** The default version of the MI interpreter is now 3 (-i=mi3).
2550 ** The output of information about multi-location breakpoints (which is
2551 syntactically incorrect in MI 2) has changed in MI 3. This affects
2552 the following commands and events:
2556 - =breakpoint-created
2557 - =breakpoint-modified
2559 The -fix-multi-location-breakpoint-output command can be used to enable
2560 this behavior with previous MI versions.
2562 ** Backtraces and frames include a new optional field addr_flags which is
2563 given after the addr field. On AArch64 this contains PAC if the address
2564 has been masked in the frame. On all other targets the field is not
2569 The testsuite now creates the files gdb.cmd (containing the arguments
2570 used to launch GDB) and gdb.in (containing all the commands sent to
2571 GDB) in the output directory for each test script. Multiple invocations
2572 are appended with .1, .2, .3 etc.
2574 * Building GDB and GDBserver now requires GNU make >= 3.82.
2576 Using another implementation of the make program or an earlier version of
2577 GNU make to build GDB or GDBserver is not supported.
2579 * Building GDB now requires GNU readline >= 7.0.
2581 GDB now bundles GNU readline 8.0, but if you choose to use
2582 --with-system-readline, only readline >= 7.0 can be used.
2584 * The TUI SingleKey keymap is now named "SingleKey". This can be used
2585 from .inputrc to bind keys in this keymap. This feature is only
2586 available when gdb is built against GNU readline 8.0 or later.
2588 * Removed targets and native configurations
2590 GDB no longer supports debugging the Cell Broadband Engine. This includes
2591 both debugging standalone Cell/B.E. SPU applications and integrated debugging
2592 of Cell/B.E. applications that use both the PPU and SPU architectures.
2598 * Removed targets and native configurations
2600 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
2601 sparc*-*-solaris2.10
2603 *** Changes in GDB 8.3
2605 * GDB and GDBserver now support access to additional registers on
2606 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
2609 * GDB now has experimental support for the compilation and injection of
2610 C++ source code into the inferior. This beta release does not include
2611 support for several language features, such as templates, constructors,
2614 This feature requires GCC 7.1 or higher built with libcp1.so
2617 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
2618 can be passed using the '[ADDRESS]:PORT' notation, or the regular
2619 'ADDRESS:PORT' method.
2621 * DWARF index cache: GDB can now automatically save indices of DWARF
2622 symbols on disk to speed up further loading of the same binaries.
2624 * Ada task switching is now supported on aarch64-elf targets when
2625 debugging a program using the Ravenscar Profile. For more information,
2626 see the "Tasking Support when using the Ravenscar Profile" section
2627 in the GDB user manual.
2629 * GDB in batch mode now exits with status 1 if the last command to be
2632 * The RISC-V target now supports target descriptions.
2634 * System call catchpoints now support system call aliases on FreeBSD.
2635 When the ABI of a system call changes in FreeBSD, this is
2636 implemented by leaving a compatibility system call using the old ABI
2637 at the existing number and allocating a new system call number for
2638 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
2639 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
2640 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
2641 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
2642 so that a system call catchpoint for the 'kevent' system call will
2643 catch invocations of both the 'kevent' and 'freebsd11_kevent'
2644 binaries. This ensures that 'kevent' system calls are caught for
2645 binaries using either the old or new ABIs.
2647 * Terminal styling is now available for the CLI and the TUI. GNU
2648 Source Highlight can additionally be used to provide styling of
2649 source code snippets. See the "set style" commands, below, for more
2652 * Removed support for old demangling styles arm, edg, gnu, hp and
2657 set debug compile-cplus-types
2658 show debug compile-cplus-types
2659 Control the display of debug output about type conversion in the
2660 C++ compile feature. Commands have no effect while compiling
2661 for other languages.
2665 Control whether debug output about files/functions skipping is
2668 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
2669 Apply a command to some frames.
2670 FLAG arguments allow to control what output to produce and how to handle
2671 errors raised when applying COMMAND to a frame.
2674 Apply a command to all threads (ignoring errors and empty output).
2675 Shortcut for 'thread apply all -s COMMAND'.
2678 Apply a command to all frames (ignoring errors and empty output).
2679 Shortcut for 'frame apply all -s COMMAND'.
2682 Apply a command to all frames of all threads (ignoring errors and empty
2684 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
2686 maint set dwarf unwinders (on|off)
2687 maint show dwarf unwinders
2688 Control whether DWARF unwinders can be used.
2691 Display a list of open files for a process.
2695 Changes to the "frame", "select-frame", and "info frame" CLI commands.
2696 These commands all now take a frame specification which
2697 is either a frame level, or one of the keywords 'level', 'address',
2698 'function', or 'view' followed by a parameter. Selecting a frame by
2699 address, or viewing a frame outside the current backtrace now
2700 requires the use of a keyword. Selecting a frame by level is
2701 unchanged. The MI comment "-stack-select-frame" is unchanged.
2703 target remote FILENAME
2704 target extended-remote FILENAME
2705 If FILENAME is a Unix domain socket, GDB will attempt to connect
2706 to this socket instead of opening FILENAME as a character device.
2708 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2709 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2710 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2711 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
2712 These commands can now print only the searched entities
2713 matching the provided regexp(s), giving a condition
2714 on the entity names or entity types. The flag -q disables
2715 printing headers or information messages.
2721 These commands now determine the syntax for the shown entities
2722 according to the language chosen by `set language'. In particular,
2723 `set language auto' means to automatically choose the language of
2726 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
2727 The 'thread apply' command accepts new FLAG arguments.
2728 FLAG arguments allow to control what output to produce and how to handle
2729 errors raised when applying COMMAND to a thread.
2731 set tui tab-width NCHARS
2732 show tui tab-width NCHARS
2733 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
2735 set style enabled [on|off]
2737 Enable or disable terminal styling. Styling is enabled by default
2738 on most hosts, but disabled by default when in batch mode.
2740 set style sources [on|off]
2742 Enable or disable source code styling. Source code styling is
2743 enabled by default, but only takes effect if styling in general is
2744 enabled, and if GDB was linked with GNU Source Highlight.
2746 set style filename foreground COLOR
2747 set style filename background COLOR
2748 set style filename intensity VALUE
2749 Control the styling of file names.
2751 set style function foreground COLOR
2752 set style function background COLOR
2753 set style function intensity VALUE
2754 Control the styling of function names.
2756 set style variable foreground COLOR
2757 set style variable background COLOR
2758 set style variable intensity VALUE
2759 Control the styling of variable names.
2761 set style address foreground COLOR
2762 set style address background COLOR
2763 set style address intensity VALUE
2764 Control the styling of addresses.
2768 ** The '-data-disassemble' MI command now accepts an '-a' option to
2769 disassemble the whole function surrounding the given program
2770 counter value or function name. Support for this feature can be
2771 verified by using the "-list-features" command, which should
2772 contain "data-disassemble-a-option".
2774 ** Command responses and notifications that include a frame now include
2775 the frame's architecture in a new "arch" attribute.
2777 * New native configurations
2779 GNU/Linux/RISC-V riscv*-*-linux*
2780 FreeBSD/riscv riscv*-*-freebsd*
2784 GNU/Linux/RISC-V riscv*-*-linux*
2785 CSKY ELF csky*-*-elf
2786 CSKY GNU/LINUX csky*-*-linux
2787 FreeBSD/riscv riscv*-*-freebsd*
2789 GNU/Linux/OpenRISC or1k*-*-linux*
2793 GDB no longer supports native debugging on versions of MS-Windows
2798 ** GDB no longer supports Python versions less than 2.6.
2800 ** The gdb.Inferior type has a new 'progspace' property, which is the program
2801 space associated to that inferior.
2803 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2804 of objfiles associated to that program space.
2806 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2807 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2810 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2811 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
2812 correct and did not work properly.
2814 ** The gdb.Value type has a new constructor, which is used to construct a
2815 gdb.Value from a Python buffer object and a gdb.Type.
2821 Enable or disable the undefined behavior sanitizer. This is
2822 disabled by default, but passing --enable-ubsan=yes or
2823 --enable-ubsan=auto to configure will enable it. Enabling this can
2824 cause a performance penalty. The undefined behavior sanitizer was
2825 first introduced in GCC 4.9.
2827 *** Changes in GDB 8.2
2829 * The 'set disassembler-options' command now supports specifying options
2830 for the MIPS target.
2832 * The 'symbol-file' command now accepts an '-o' option to add a relative
2833 offset to all sections.
2835 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2836 a relative offset to all sections, but it allows to override the load
2837 address of individual sections using '-s'.
2839 * The 'add-symbol-file' command no longer requires the second argument
2840 (address of the text section).
2842 * The endianness used with the 'set endian auto' mode in the absence of
2843 an executable selected for debugging is now the last endianness chosen
2844 either by one of the 'set endian big' and 'set endian little' commands
2845 or by inferring from the last executable used, rather than the startup
2848 * The pager now allows a "c" response, meaning to disable the pager
2849 for the rest of the current command.
2851 * The commands 'info variables/functions/types' now show the source line
2852 numbers of symbol definitions when available.
2854 * 'info proc' now works on running processes on FreeBSD systems and core
2855 files created on FreeBSD systems.
2857 * C expressions can now use _Alignof, and C++ expressions can now use
2860 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
2861 the vector length while the process is running.
2867 Control display of debugging info regarding the FreeBSD native target.
2869 set|show varsize-limit
2870 This new setting allows the user to control the maximum size of Ada
2871 objects being printed when those objects have a variable type,
2872 instead of that maximum size being hardcoded to 65536 bytes.
2874 set|show record btrace cpu
2875 Controls the processor to be used for enabling errata workarounds for
2876 branch trace decode.
2878 maint check libthread-db
2879 Run integrity checks on the current inferior's thread debugging
2882 maint set check-libthread-db (on|off)
2883 maint show check-libthread-db
2884 Control whether to run integrity checks on inferior specific thread
2885 debugging libraries as they are loaded. The default is not to
2886 perform such checks.
2890 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2892 ** The commands attached to a breakpoint can be set by assigning to
2893 the breakpoint's "commands" field.
2895 ** gdb.execute can now execute multi-line gdb commands.
2897 ** The new functions gdb.convenience_variable and
2898 gdb.set_convenience_variable can be used to get and set the value
2899 of convenience variables.
2901 ** A gdb.Parameter will no longer print the "set" help text on an
2902 ordinary "set"; instead by default a "set" will be silent unless
2903 the get_set_string method returns a non-empty string.
2907 RiscV ELF riscv*-*-elf
2909 * Removed targets and native configurations
2911 m88k running OpenBSD m88*-*-openbsd*
2912 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2913 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2914 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2916 * Aarch64/Linux hardware watchpoints improvements
2918 Hardware watchpoints on unaligned addresses are now properly
2919 supported when running Linux kernel 4.10 or higher: read and access
2920 watchpoints are no longer spuriously missed, and all watchpoints
2921 lengths between 1 and 8 bytes are supported. On older kernels,
2922 watchpoints set on unaligned addresses are no longer missed, with
2923 the tradeoff that there is a possibility of false hits being
2928 --enable-codesign=CERT
2929 This can be used to invoke "codesign -s CERT" after building gdb.
2930 This option is useful on macOS, where code signing is required for
2931 gdb to work properly.
2933 --disable-gdbcli has been removed
2934 This is now silently accepted, but does nothing.
2936 *** Changes in GDB 8.1
2938 * GDB now supports dynamically creating arbitrary register groups specified
2939 in XML target descriptions. This allows for finer grain grouping of
2940 registers on systems with a large amount of registers.
2942 * The 'ptype' command now accepts a '/o' flag, which prints the
2943 offsets and sizes of fields in a struct, like the pahole(1) tool.
2945 * New "--readnever" command line option instructs GDB to not read each
2946 symbol file's symbolic debug information. This makes startup faster
2947 but at the expense of not being able to perform symbolic debugging.
2948 This option is intended for use cases where symbolic debugging will
2949 not be used, e.g., when you only need to dump the debuggee's core.
2951 * GDB now uses the GNU MPFR library, if available, to emulate target
2952 floating-point arithmetic during expression evaluation when the target
2953 uses different floating-point formats than the host. At least version
2954 3.1 of GNU MPFR is required.
2956 * GDB now supports access to the guarded-storage-control registers and the
2957 software-based guarded-storage broadcast control registers on IBM z14.
2959 * On Unix systems, GDB now supports transmitting environment variables
2960 that are to be set or unset to GDBserver. These variables will
2961 affect the environment to be passed to the remote inferior.
2963 To inform GDB of environment variables that are to be transmitted to
2964 GDBserver, use the "set environment" command. Only user set
2965 environment variables are sent to GDBserver.
2967 To inform GDB of environment variables that are to be unset before
2968 the remote inferior is started by the GDBserver, use the "unset
2969 environment" command.
2971 * Completion improvements
2973 ** GDB can now complete function parameters in linespecs and
2974 explicit locations without quoting. When setting breakpoints,
2975 quoting around functions names to help with TAB-completion is
2976 generally no longer necessary. For example, this now completes
2979 (gdb) b function(in[TAB]
2980 (gdb) b function(int)
2982 Related, GDB is no longer confused with completing functions in
2983 C++ anonymous namespaces:
2986 (gdb) b (anonymous namespace)::[TAB][TAB]
2987 (anonymous namespace)::a_function()
2988 (anonymous namespace)::b_function()
2990 ** GDB now has much improved linespec and explicit locations TAB
2991 completion support, that better understands what you're
2992 completing and offers better suggestions. For example, GDB no
2993 longer offers data symbols as possible completions when you're
2994 setting a breakpoint.
2996 ** GDB now TAB-completes label symbol names.
2998 ** The "complete" command now mimics TAB completion accurately.
3000 * New command line options (gcore)
3003 Dump all memory mappings.
3005 * Breakpoints on C++ functions are now set on all scopes by default
3007 By default, breakpoints on functions/methods are now interpreted as
3008 specifying all functions with the given name ignoring missing
3009 leading scopes (namespaces and classes).
3011 For example, assuming a C++ program with symbols named:
3016 both commands "break func()" and "break B::func()" set a breakpoint
3019 You can use the new flag "-qualified" to override this. This makes
3020 GDB interpret the specified function name as a complete
3021 fully-qualified name instead. For example, using the same C++
3022 program, the "break -q B::func" command sets a breakpoint on
3023 "B::func", only. A parameter has been added to the Python
3024 gdb.Breakpoint constructor to achieve the same result when creating
3025 a breakpoint from Python.
3027 * Breakpoints on functions marked with C++ ABI tags
3029 GDB can now set breakpoints on functions marked with C++ ABI tags
3030 (e.g., [abi:cxx11]). See here for a description of ABI tags:
3031 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
3033 Functions with a C++11 abi tag are demangled/displayed like this:
3035 function[abi:cxx11](int)
3038 You can now set a breakpoint on such functions simply as if they had
3041 (gdb) b function(int)
3043 Or if you need to disambiguate between tags, like:
3045 (gdb) b function[abi:other_tag](int)
3047 Tab completion was adjusted accordingly as well.
3051 ** New events gdb.new_inferior, gdb.inferior_deleted, and
3052 gdb.new_thread are emitted. See the manual for further
3053 description of these.
3055 ** A new function, "gdb.rbreak" has been added to the Python API.
3056 This function allows the setting of a large number of breakpoints
3057 via a regex pattern in Python. See the manual for further details.
3059 ** Python breakpoints can now accept explicit locations. See the
3060 manual for a further description of this feature.
3063 * New features in the GDB remote stub, GDBserver
3065 ** GDBserver is now able to start inferior processes with a
3066 specified initial working directory.
3068 The user can set the desired working directory to be used from
3069 GDB using the new "set cwd" command.
3071 ** New "--selftest" command line option runs some GDBserver self
3072 tests. These self tests are disabled in releases.
3074 ** On Unix systems, GDBserver now does globbing expansion and variable
3075 substitution in inferior command line arguments.
3077 This is done by starting inferiors using a shell, like GDB does.
3078 See "set startup-with-shell" in the user manual for how to disable
3079 this from GDB when using "target extended-remote". When using
3080 "target remote", you can disable the startup with shell by using the
3081 new "--no-startup-with-shell" GDBserver command line option.
3083 ** On Unix systems, GDBserver now supports receiving environment
3084 variables that are to be set or unset from GDB. These variables
3085 will affect the environment to be passed to the inferior.
3087 * When catching an Ada exception raised with a message, GDB now prints
3088 the message in the catchpoint hit notification. In GDB/MI mode, that
3089 information is provided as an extra field named "exception-message"
3090 in the *stopped notification.
3092 * Trait objects can now be inspected When debugging Rust code. This
3093 requires compiler support which will appear in Rust 1.24.
3095 * New remote packets
3097 QEnvironmentHexEncoded
3098 Inform GDBserver of an environment variable that is to be passed to
3099 the inferior when starting it.
3102 Inform GDBserver of an environment variable that is to be unset
3103 before starting the remote inferior.
3106 Inform GDBserver that the environment should be reset (i.e.,
3107 user-set environment variables should be unset).
3110 Indicates whether the inferior must be started with a shell or not.
3113 Tell GDBserver that the inferior to be started should use a specific
3116 * The "maintenance print c-tdesc" command now takes an optional
3117 argument which is the file name of XML target description.
3119 * The "maintenance selftest" command now takes an optional argument to
3120 filter the tests to be run.
3122 * The "enable", and "disable" commands now accept a range of
3123 breakpoint locations, e.g. "enable 1.3-5".
3128 Set and show the current working directory for the inferior.
3130 set|show compile-gcc
3131 Set and show compilation command used for compiling and injecting code
3132 with the 'compile' commands.
3134 set debug separate-debug-file
3135 show debug separate-debug-file
3136 Control the display of debug output about separate debug file search.
3138 set dump-excluded-mappings
3139 show dump-excluded-mappings
3140 Control whether mappings marked with the VM_DONTDUMP flag should be
3141 dumped when generating a core file.
3143 maint info selftests
3144 List the registered selftests.
3147 Start the debugged program stopping at the first instruction.
3150 Control display of debugging messages related to OpenRISC targets.
3152 set|show print type nested-type-limit
3153 Set and show the limit of nesting level for nested types that the
3154 type printer will show.
3156 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
3159 * Safer/improved support for debugging with no debug info
3161 GDB no longer assumes functions with no debug information return
3164 This means that GDB now refuses to call such functions unless you
3165 tell it the function's type, by either casting the call to the
3166 declared return type, or by casting the function to a function
3167 pointer of the right type, and calling that:
3169 (gdb) p getenv ("PATH")
3170 'getenv' has unknown return type; cast the call to its declared return type
3171 (gdb) p (char *) getenv ("PATH")
3172 $1 = 0x7fffffffe "/usr/local/bin:/"...
3173 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
3174 $2 = 0x7fffffffe "/usr/local/bin:/"...
3176 Similarly, GDB no longer assumes that global variables with no debug
3177 info have type 'int', and refuses to print the variable's value
3178 unless you tell it the variable's type:
3181 'var' has unknown type; cast it to its declared type
3185 * New native configurations
3187 FreeBSD/aarch64 aarch64*-*-freebsd*
3188 FreeBSD/arm arm*-*-freebsd*
3192 FreeBSD/aarch64 aarch64*-*-freebsd*
3193 FreeBSD/arm arm*-*-freebsd*
3194 OpenRISC ELF or1k*-*-elf
3196 * Removed targets and native configurations
3198 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
3200 *** Changes in GDB 8.0
3202 * GDB now supports access to the PKU register on GNU/Linux. The register is
3203 added by the Memory Protection Keys for Userspace feature which will be
3204 available in future Intel CPUs.
3206 * GDB now supports C++11 rvalue references.
3210 ** New functions to start, stop and access a running btrace recording.
3211 ** Rvalue references are now supported in gdb.Type.
3213 * GDB now supports recording and replaying rdrand and rdseed Intel 64
3216 * Building GDB and GDBserver now requires a C++11 compiler.
3218 For example, GCC 4.8 or later.
3220 It is no longer possible to build GDB or GDBserver with a C
3221 compiler. The --disable-build-with-cxx configure option has been
3224 * Building GDB and GDBserver now requires GNU make >= 3.81.
3226 It is no longer supported to build GDB or GDBserver with another
3227 implementation of the make program or an earlier version of GNU make.
3229 * Native debugging on MS-Windows supports command-line redirection
3231 Command-line arguments used for starting programs on MS-Windows can
3232 now include redirection symbols supported by native Windows shells,
3233 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
3234 as "run", "start", and "set args", as well as the corresponding MI
3237 * Support for thread names on MS-Windows.
3239 GDB now catches and handles the special exception that programs
3240 running on MS-Windows use to assign names to threads in the
3243 * Support for Java programs compiled with gcj has been removed.
3245 * User commands now accept an unlimited number of arguments.
3246 Previously, only up to 10 was accepted.
3248 * The "eval" command now expands user-defined command arguments.
3250 This makes it easier to process a variable number of arguments:
3255 eval "print $arg%d", $i
3260 * Target descriptions can now describe registers for sparc32 and sparc64.
3262 * GDB now supports DWARF version 5 (debug information format).
3263 Its .debug_names index is not yet supported.
3265 * New native configurations
3267 FreeBSD/mips mips*-*-freebsd
3271 Synopsys ARC arc*-*-elf32
3272 FreeBSD/mips mips*-*-freebsd
3274 * Removed targets and native configurations
3276 Alpha running FreeBSD alpha*-*-freebsd*
3277 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
3282 Erases all the flash memory regions reported by the target.
3284 maint print arc arc-instruction address
3285 Print internal disassembler information about instruction at a given address.
3289 set disassembler-options
3290 show disassembler-options
3291 Controls the passing of target specific information to the disassembler.
3292 If it is necessary to specify more than one disassembler option then
3293 multiple options can be placed together into a comma separated list.
3294 The default value is the empty string. Currently, the only supported
3295 targets are ARM, PowerPC and S/390.
3300 Erases all the flash memory regions reported by the target. This is
3301 equivalent to the CLI command flash-erase.
3303 -file-list-shared-libraries
3304 List the shared libraries in the program. This is
3305 equivalent to the CLI command "info shared".
3308 Catchpoints stopping the program when Ada exceptions are
3309 handled. This is equivalent to the CLI command "catch handlers".
3311 *** Changes in GDB 7.12
3313 * GDB and GDBserver now build with a C++ compiler by default.
3315 The --enable-build-with-cxx configure option is now enabled by
3316 default. One must now explicitly configure with
3317 --disable-build-with-cxx in order to build with a C compiler. This
3318 option will be removed in a future release.
3320 * GDBserver now supports recording btrace without maintaining an active
3323 * GDB now supports a negative repeat count in the 'x' command to examine
3324 memory backward from the given address. For example:
3327 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
3328 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
3329 (gdb) x/-5i 0x0000000000400580
3330 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
3331 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
3332 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
3333 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
3334 0x40057b <main(int, char**)+25>:
3335 callq 0x400536 <Func1(int, char const*)>
3337 * Fortran: Support structures with fields of dynamic types and
3338 arrays of dynamic types.
3340 * The symbol dumping maintenance commands have new syntax.
3341 maint print symbols [-pc address] [--] [filename]
3342 maint print symbols [-objfile objfile] [-source source] [--] [filename]
3343 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
3344 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
3345 maint print msymbols [-objfile objfile] [--] [filename]
3347 * GDB now supports multibit bitfields and enums in target register
3350 * New Python-based convenience function $_as_string(val), which returns
3351 the textual representation of a value. This function is especially
3352 useful to obtain the text label of an enum value.
3354 * Intel MPX bound violation handling.
3356 Segmentation faults caused by a Intel MPX boundary violation
3357 now display the kind of violation (upper or lower), the memory
3358 address accessed and the memory bounds, along with the usual
3359 signal received and code location.
3363 Program received signal SIGSEGV, Segmentation fault
3364 Upper bound violation while accessing address 0x7fffffffc3b3
3365 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
3366 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
3368 * Rust language support.
3369 GDB now supports debugging programs written in the Rust programming
3370 language. See https://www.rust-lang.org/ for more information about
3373 * Support for running interpreters on specified input/output devices
3375 GDB now supports a new mechanism that allows frontends to provide
3376 fully featured GDB console views, as a better alternative to
3377 building such views on top of the "-interpreter-exec console"
3378 command. See the new "new-ui" command below. With that command,
3379 frontends can now start GDB in the traditional command-line mode
3380 running in an embedded terminal emulator widget, and create a
3381 separate MI interpreter running on a specified i/o device. In this
3382 way, GDB handles line editing, history, tab completion, etc. in the
3383 console all by itself, and the GUI uses the separate MI interpreter
3384 for its own control and synchronization, invisible to the command
3387 * The "catch syscall" command catches groups of related syscalls.
3389 The "catch syscall" command now supports catching a group of related
3390 syscalls using the 'group:' or 'g:' prefix.
3395 skip -gfile file-glob-pattern
3396 skip -function function
3397 skip -rfunction regular-expression
3398 A generalized form of the skip command, with new support for
3399 glob-style file names and regular expressions for function names.
3400 Additionally, a file spec and a function spec may now be combined.
3402 maint info line-table REGEXP
3403 Display the contents of GDB's internal line table data structure.
3406 Run any GDB unit tests that were compiled in.
3409 Start a new user interface instance running INTERP as interpreter,
3410 using the TTY file for input/output.
3414 ** gdb.Breakpoint objects have a new attribute "pending", which
3415 indicates whether the breakpoint is pending.
3416 ** Three new breakpoint-related events have been added:
3417 gdb.breakpoint_created, gdb.breakpoint_modified, and
3418 gdb.breakpoint_deleted.
3420 signal-event EVENTID
3421 Signal ("set") the given MS-Windows event object. This is used in
3422 conjunction with the Windows JIT debugging (AeDebug) support, where
3423 the OS suspends a crashing process until a debugger can attach to
3424 it. Resuming the crashing process, in order to debug it, is done by
3425 signalling an event.
3427 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
3428 was added in GDBserver, including JIT compiling fast tracepoint's
3429 conditional expression bytecode into native code.
3431 * Support for various remote target protocols and ROM monitors has
3434 target m32rsdi Remote M32R debugging over SDI
3435 target mips MIPS remote debugging protocol
3436 target pmon PMON ROM monitor
3437 target ddb NEC's DDB variant of PMON for Vr4300
3438 target rockhopper NEC RockHopper variant of PMON
3439 target lsi LSI variant of PMO
3441 * Support for tracepoints and fast tracepoints on powerpc-linux,
3442 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
3443 including JIT compiling fast tracepoint's conditional expression
3444 bytecode into native code.
3446 * MI async record =record-started now includes the method and format used for
3447 recording. For example:
3449 =record-started,thread-group="i1",method="btrace",format="bts"
3451 * MI async record =thread-selected now includes the frame field. For example:
3453 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
3457 Andes NDS32 nds32*-*-elf
3459 *** Changes in GDB 7.11
3461 * GDB now supports debugging kernel-based threads on FreeBSD.
3463 * Per-inferior thread numbers
3465 Thread numbers are now per inferior instead of global. If you're
3466 debugging multiple inferiors, GDB displays thread IDs using a
3467 qualified INF_NUM.THR_NUM form. For example:
3471 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
3472 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
3473 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
3474 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
3476 As consequence, thread numbers as visible in the $_thread
3477 convenience variable and in Python's InferiorThread.num attribute
3478 are no longer unique between inferiors.
3480 GDB now maintains a second thread ID per thread, referred to as the
3481 global thread ID, which is the new equivalent of thread numbers in
3482 previous releases. See also $_gthread below.
3484 For backwards compatibility, MI's thread IDs always refer to global
3487 * Commands that accept thread IDs now accept the qualified
3488 INF_NUM.THR_NUM form as well. For example:
3491 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
3494 * In commands that accept a list of thread IDs, you can now refer to
3495 all threads of an inferior using a star wildcard. GDB accepts
3496 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
3497 refer to all threads of the current inferior. For example, "info
3500 * You can use "info threads -gid" to display the global thread ID of
3503 * The new convenience variable $_gthread holds the global number of
3506 * The new convenience variable $_inferior holds the number of the
3509 * GDB now displays the ID and name of the thread that hit a breakpoint
3510 or received a signal, if your program is multi-threaded. For
3513 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
3514 Thread 1 "main" received signal SIGINT, Interrupt.
3516 * Record btrace now supports non-stop mode.
3518 * Support for tracepoints on aarch64-linux was added in GDBserver.
3520 * The 'record instruction-history' command now indicates speculative execution
3521 when using the Intel Processor Trace recording format.
3523 * GDB now allows users to specify explicit locations, bypassing
3524 the linespec parser. This feature is also available to GDB/MI
3527 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
3528 GDB now is able to debug both AArch64 applications and ARM applications
3531 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
3532 including JIT compiling fast tracepoint's conditional expression bytecode
3535 * GDB now supports displaced stepping on AArch64 GNU/Linux.
3537 * "info threads", "info inferiors", "info display", "info checkpoints"
3538 and "maint info program-spaces" now list the corresponding items in
3539 ascending ID order, for consistency with all other "info" commands.
3541 * In Ada, the overloads selection menu has been enhanced to display the
3542 parameter types and the return types for the matching overloaded subprograms.
3546 maint set target-non-stop (on|off|auto)
3547 maint show target-non-stop
3548 Control whether GDB targets always operate in non-stop mode even if
3549 "set non-stop" is "off". The default is "auto", meaning non-stop
3550 mode is enabled if supported by the target.
3552 maint set bfd-sharing
3553 maint show bfd-sharing
3554 Control the reuse of bfd objects.
3557 show debug bfd-cache
3558 Control display of debugging info regarding bfd caching.
3562 Control display of debugging info regarding FreeBSD threads.
3564 set remote multiprocess-extensions-packet
3565 show remote multiprocess-extensions-packet
3566 Set/show the use of the remote protocol multiprocess extensions.
3568 set remote thread-events
3569 show remote thread-events
3570 Set/show the use of thread create/exit events.
3572 set ada print-signatures on|off
3573 show ada print-signatures"
3574 Control whether parameter types and return types are displayed in overloads
3575 selection menus. It is activated (@code{on}) by default.
3579 Controls the maximum size of memory, in bytes, that GDB will
3580 allocate for value contents. Prevents incorrect programs from
3581 causing GDB to allocate overly large buffers. Default is 64k.
3583 * The "disassemble" command accepts a new modifier: /s.
3584 It prints mixed source+disassembly like /m with two differences:
3585 - disassembled instructions are now printed in program order, and
3586 - and source for all relevant files is now printed.
3587 The "/m" option is now considered deprecated: its "source-centric"
3588 output hasn't proved useful in practice.
3590 * The "record instruction-history" command accepts a new modifier: /s.
3591 It behaves exactly like /m and prints mixed source+disassembly.
3593 * The "set scheduler-locking" command supports a new mode "replay".
3594 It behaves like "off" in record mode and like "on" in replay mode.
3596 * Support for various ROM monitors has been removed:
3598 target dbug dBUG ROM monitor for Motorola ColdFire
3599 target picobug Motorola picobug monitor
3600 target dink32 DINK32 ROM monitor for PowerPC
3601 target m32r Renesas M32R/D ROM monitor
3602 target mon2000 mon2000 ROM monitor
3603 target ppcbug PPCBUG ROM monitor for PowerPC
3605 * Support for reading/writing memory and extracting values on architectures
3606 whose memory is addressable in units of any integral multiple of 8 bits.
3609 Allows to break when an Ada exception is handled.
3611 * New remote packets
3614 Indicates that an exec system call was executed.
3616 exec-events feature in qSupported
3617 The qSupported packet allows GDB to request support for exec
3618 events using the new 'gdbfeature' exec-event, and the qSupported
3619 response can contain the corresponding 'stubfeature'. Set and
3620 show commands can be used to display whether these features are enabled.
3623 Equivalent to interrupting with the ^C character, but works in
3626 thread created stop reason (T05 create:...)
3627 Indicates that the thread was just created and is stopped at entry.
3629 thread exit stop reply (w exitcode;tid)
3630 Indicates that the thread has terminated.
3633 Enables/disables thread create and exit event reporting. For
3634 example, this is used in non-stop mode when GDB stops a set of
3635 threads and synchronously waits for the their corresponding stop
3636 replies. Without exit events, if one of the threads exits, GDB
3637 would hang forever not knowing that it should no longer expect a
3638 stop for that same thread.
3641 Indicates that there are no resumed threads left in the target (all
3642 threads are stopped). The remote stub reports support for this stop
3643 reply to GDB's qSupported query.
3646 Enables/disables catching syscalls from the inferior process.
3647 The remote stub reports support for this packet to GDB's qSupported query.
3649 syscall_entry stop reason
3650 Indicates that a syscall was just called.
3652 syscall_return stop reason
3653 Indicates that a syscall just returned.
3655 * Extended-remote exec events
3657 ** GDB now has support for exec events on extended-remote Linux targets.
3658 For such targets with Linux kernels 2.5.46 and later, this enables
3659 follow-exec-mode and exec catchpoints.
3661 set remote exec-event-feature-packet
3662 show remote exec-event-feature-packet
3663 Set/show the use of the remote exec event feature.
3665 * Thread names in remote protocol
3667 The reply to qXfer:threads:read may now include a name attribute for each
3670 * Target remote mode fork and exec events
3672 ** GDB now has support for fork and exec events on target remote mode
3673 Linux targets. For such targets with Linux kernels 2.5.46 and later,
3674 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
3675 fork and exec catchpoints.
3677 * Remote syscall events
3679 ** GDB now has support for catch syscall on remote Linux targets,
3680 currently enabled on x86/x86_64 architectures.
3682 set remote catch-syscall-packet
3683 show remote catch-syscall-packet
3684 Set/show the use of the remote catch syscall feature.
3688 ** The -var-set-format command now accepts the zero-hexadecimal
3689 format. It outputs data in hexadecimal format with zero-padding on the
3694 ** gdb.InferiorThread objects have a new attribute "global_num",
3695 which refers to the thread's global thread ID. The existing
3696 "num" attribute now refers to the thread's per-inferior number.
3697 See "Per-inferior thread numbers" above.
3698 ** gdb.InferiorThread objects have a new attribute "inferior", which
3699 is the Inferior object the thread belongs to.
3701 *** Changes in GDB 7.10
3703 * Support for process record-replay and reverse debugging on aarch64*-linux*
3704 targets has been added. GDB now supports recording of A64 instruction set
3705 including advance SIMD instructions.
3707 * Support for Sun's version of the "stabs" debug file format has been removed.
3709 * GDB now honors the content of the file /proc/PID/coredump_filter
3710 (PID is the process ID) on GNU/Linux systems. This file can be used
3711 to specify the types of memory mappings that will be included in a
3712 corefile. For more information, please refer to the manual page of
3713 "core(5)". GDB also has a new command: "set use-coredump-filter
3714 on|off". It allows to set whether GDB will read the content of the
3715 /proc/PID/coredump_filter file when generating a corefile.
3717 * The "info os" command on GNU/Linux can now display information on
3719 "info os cpus" Listing of all cpus/cores on the system
3721 * GDB has two new commands: "set serial parity odd|even|none" and
3722 "show serial parity". These allows to set or show parity for the
3725 * The "info source" command now displays the producer string if it was
3726 present in the debug info. This typically includes the compiler version
3727 and may include things like its command line arguments.
3729 * The "info dll", an alias of the "info sharedlibrary" command,
3730 is now available on all platforms.
3732 * Directory names supplied to the "set sysroot" commands may be
3733 prefixed with "target:" to tell GDB to access shared libraries from
3734 the target system, be it local or remote. This replaces the prefix
3735 "remote:". The default sysroot has been changed from "" to
3736 "target:". "remote:" is automatically converted to "target:" for
3737 backward compatibility.
3739 * The system root specified by "set sysroot" will be prepended to the
3740 filename of the main executable (if reported to GDB as absolute by
3741 the operating system) when starting processes remotely, and when
3742 attaching to already-running local or remote processes.
3744 * GDB now supports automatic location and retrieval of executable
3745 files from remote targets. Remote debugging can now be initiated
3746 using only a "target remote" or "target extended-remote" command
3747 (no "set sysroot" or "file" commands are required). See "New remote
3750 * The "dump" command now supports verilog hex format.
3752 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
3754 * On GNU/Linux, GDB and gdbserver are now able to access executable
3755 and shared library files without a "set sysroot" command when
3756 attaching to processes running in different mount namespaces from
3757 the debugger. This makes it possible to attach to processes in
3758 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
3759 See "New remote packets" below.
3761 * The "tui reg" command now provides completion for all of the
3762 available register groups, including target specific groups.
3764 * The HISTSIZE environment variable is no longer read when determining
3765 the size of GDB's command history. GDB now instead reads the dedicated
3766 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
3767 disables truncation of command history. Non-numeric values of GDBHISTSIZE
3772 ** Memory ports can now be unbuffered.
3776 ** gdb.Objfile objects have a new attribute "username",
3777 which is the name of the objfile as specified by the user,
3778 without, for example, resolving symlinks.
3779 ** You can now write frame unwinders in Python.
3780 ** gdb.Type objects have a new method "optimized_out",
3781 returning optimized out gdb.Value instance of this type.
3782 ** gdb.Value objects have new methods "reference_value" and
3783 "const_value" which return a reference to the value and a
3784 "const" version of the value respectively.
3788 maint print symbol-cache
3789 Print the contents of the symbol cache.
3791 maint print symbol-cache-statistics
3792 Print statistics of symbol cache usage.
3794 maint flush-symbol-cache
3795 Flush the contents of the symbol cache.
3799 Start branch trace recording using Branch Trace Store (BTS) format.
3802 Evaluate expression by using the compiler and print result.
3806 Explicit commands for enabling and disabling tui mode.
3809 set mpx bound on i386 and amd64
3810 Support for bound table investigation on Intel MPX enabled applications.
3814 Start branch trace recording using Intel Processor Trace format.
3817 Print information about branch tracing internals.
3819 maint btrace packet-history
3820 Print the raw branch tracing data.
3822 maint btrace clear-packet-history
3823 Discard the stored raw branch tracing data.
3826 Discard all branch tracing data. It will be fetched and processed
3827 anew by the next "record" command.
3832 Renamed from "set debug dwarf2-die".
3833 show debug dwarf-die
3834 Renamed from "show debug dwarf2-die".
3836 set debug dwarf-read
3837 Renamed from "set debug dwarf2-read".
3838 show debug dwarf-read
3839 Renamed from "show debug dwarf2-read".
3841 maint set dwarf always-disassemble
3842 Renamed from "maint set dwarf2 always-disassemble".
3843 maint show dwarf always-disassemble
3844 Renamed from "maint show dwarf2 always-disassemble".
3846 maint set dwarf max-cache-age
3847 Renamed from "maint set dwarf2 max-cache-age".
3848 maint show dwarf max-cache-age
3849 Renamed from "maint show dwarf2 max-cache-age".
3851 set debug dwarf-line
3852 show debug dwarf-line
3853 Control display of debugging info regarding DWARF line processing.
3856 show max-completions
3857 Set the maximum number of candidates to be considered during
3858 completion. The default value is 200. This limit allows GDB
3859 to avoid generating large completion lists, the computation of
3860 which can cause the debugger to become temporarily unresponsive.
3862 set history remove-duplicates
3863 show history remove-duplicates
3864 Control the removal of duplicate history entries.
3866 maint set symbol-cache-size
3867 maint show symbol-cache-size
3868 Control the size of the symbol cache.
3870 set|show record btrace bts buffer-size
3871 Set and show the size of the ring buffer used for branch tracing in
3873 The obtained size may differ from the requested size. Use "info
3874 record" to see the obtained buffer size.
3876 set debug linux-namespaces
3877 show debug linux-namespaces
3878 Control display of debugging info regarding Linux namespaces.
3880 set|show record btrace pt buffer-size
3881 Set and show the size of the ring buffer used for branch tracing in
3882 Intel Processor Trace format.
3883 The obtained size may differ from the requested size. Use "info
3884 record" to see the obtained buffer size.
3886 maint set|show btrace pt skip-pad
3887 Set and show whether PAD packets are skipped when computing the
3890 * The command 'thread apply all' can now support new option '-ascending'
3891 to call its specified command for all threads in ascending order.
3893 * Python/Guile scripting
3895 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3896 special section named `.debug_gdb_scripts'.
3898 * New remote packets
3900 qXfer:btrace-conf:read
3901 Return the branch trace configuration for the current thread.
3903 Qbtrace-conf:bts:size
3904 Set the requested ring buffer size for branch tracing in BTS format.
3907 Enable Intel Processor Trace-based branch tracing for the current
3908 process. The remote stub reports support for this packet to GDB's
3911 Qbtrace-conf:pt:size
3912 Set the requested ring buffer size for branch tracing in Intel Processor
3916 Indicates a memory breakpoint instruction was executed, irrespective
3917 of whether it was GDB that planted the breakpoint or the breakpoint
3918 is hardcoded in the program. This is required for correct non-stop
3922 Indicates the target stopped for a hardware breakpoint. This is
3923 required for correct non-stop mode operation.
3926 Return information about files on the remote system.
3928 qXfer:exec-file:read
3929 Return the full absolute name of the file that was executed to
3930 create a process running on the remote system.
3933 Select the filesystem on which vFile: operations with filename
3934 arguments will operate. This is required for GDB to be able to
3935 access files on remote targets where the remote stub does not
3936 share a common filesystem with the inferior(s).
3939 Indicates that a fork system call was executed.
3942 Indicates that a vfork system call was executed.
3944 vforkdone stop reason
3945 Indicates that a vfork child of the specified process has executed
3946 an exec or exit, allowing the vfork parent to resume execution.
3948 fork-events and vfork-events features in qSupported
3949 The qSupported packet allows GDB to request support for fork and
3950 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3951 and the qSupported response can contain the corresponding
3952 'stubfeatures'. Set and show commands can be used to display
3953 whether these features are enabled.
3955 * Extended-remote fork events
3957 ** GDB now has support for fork events on extended-remote Linux
3958 targets. For targets with Linux kernels 2.5.60 and later, this
3959 enables follow-fork-mode and detach-on-fork for both fork and
3960 vfork, as well as fork and vfork catchpoints.
3962 * The info record command now shows the recording format and the
3963 branch tracing configuration for the current thread when using
3964 the btrace record target.
3965 For the BTS format, it shows the ring buffer size.
3967 * GDB now has support for DTrace USDT (Userland Static Defined
3968 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3970 * GDB now supports access to vector registers on S/390 GNU/Linux
3973 * Removed command line options
3975 -xdb HP-UX XDB compatibility mode.
3977 * Removed targets and native configurations
3979 HP/PA running HP-UX hppa*-*-hpux*
3980 Itanium running HP-UX ia64-*-hpux*
3982 * New configure options
3985 This configure option allows the user to build GDB with support for
3986 Intel Processor Trace (default: auto). This requires libipt.
3988 --with-libipt-prefix=PATH
3989 Specify the path to the version of libipt that GDB should use.
3990 $PATH/include should contain the intel-pt.h header and
3991 $PATH/lib should contain the libipt.so library.
3993 *** Changes in GDB 7.9.1
3997 ** Xmethods can now specify a result type.
3999 *** Changes in GDB 7.9
4001 * GDB now supports hardware watchpoints on x86 GNU Hurd.
4005 ** You can now access frame registers from Python scripts.
4006 ** New attribute 'producer' for gdb.Symtab objects.
4007 ** gdb.Objfile objects have a new attribute "progspace",
4008 which is the gdb.Progspace object of the containing program space.
4009 ** gdb.Objfile objects have a new attribute "owner".
4010 ** gdb.Objfile objects have a new attribute "build_id",
4011 which is the build ID generated when the file was built.
4012 ** gdb.Objfile objects have a new method "add_separate_debug_file".
4013 ** A new event "gdb.clear_objfiles" has been added, triggered when
4014 selecting a new file to debug.
4015 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
4016 ** New function gdb.lookup_objfile.
4018 New events which are triggered when GDB modifies the state of the
4021 ** gdb.events.inferior_call_pre: Function call is about to be made.
4022 ** gdb.events.inferior_call_post: Function call has just been made.
4023 ** gdb.events.memory_changed: A memory location has been altered.
4024 ** gdb.events.register_changed: A register has been altered.
4026 * New Python-based convenience functions:
4028 ** $_caller_is(name [, number_of_frames])
4029 ** $_caller_matches(regexp [, number_of_frames])
4030 ** $_any_caller_is(name [, number_of_frames])
4031 ** $_any_caller_matches(regexp [, number_of_frames])
4033 * GDB now supports the compilation and injection of source code into
4034 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
4035 to compile the source code to object code, and if successful, inject
4036 and execute that code within the current context of the inferior.
4037 Currently the C language is supported. The commands used to
4038 interface with this new feature are:
4040 compile code [-raw|-r] [--] [source code]
4041 compile file [-raw|-r] filename
4045 demangle [-l language] [--] name
4046 Demangle "name" in the specified language, or the current language
4047 if elided. This command is renamed from the "maint demangle" command.
4048 The latter is kept as a no-op to avoid "maint demangle" being interpreted
4049 as "maint demangler-warning".
4051 queue-signal signal-name-or-number
4052 Queue a signal to be delivered to the thread when it is resumed.
4054 add-auto-load-scripts-directory directory
4055 Add entries to the list of directories from which to load auto-loaded
4058 maint print user-registers
4059 List all currently available "user" registers.
4061 compile code [-r|-raw] [--] [source code]
4062 Compile, inject, and execute in the inferior the executable object
4063 code produced by compiling the provided source code.
4065 compile file [-r|-raw] filename
4066 Compile and inject into the inferior the executable object code
4067 produced by compiling the source code stored in the filename
4070 * On resume, GDB now always passes the signal the program had stopped
4071 for to the thread the signal was sent to, even if the user changed
4072 threads before resuming. Previously GDB would often (but not
4073 always) deliver the signal to the thread that happens to be current
4076 * Conversely, the "signal" command now consistently delivers the
4077 requested signal to the current thread. GDB now asks for
4078 confirmation if the program had stopped for a signal and the user
4079 switched threads meanwhile.
4081 * "breakpoint always-inserted" modes "off" and "auto" merged.
4083 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
4084 won't remove breakpoints from the target until all threads stop,
4085 even in non-stop mode. The "auto" mode has been removed, and "off"
4086 is now the default mode.
4090 set debug symbol-lookup
4091 show debug symbol-lookup
4092 Control display of debugging info regarding symbol lookup.
4096 ** The -list-thread-groups command outputs an exit-code field for
4097 inferiors that have exited.
4101 MIPS SDE mips*-sde*-elf*
4105 Support for these obsolete configurations has been removed.
4107 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
4108 SGI Irix-5.x mips-*-irix5*
4109 SGI Irix-6.x mips-*-irix6*
4110 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
4111 VAX running Ultrix vax-*-ultrix*
4113 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
4114 and "assf"), have been removed. Use the "sharedlibrary" command, or
4115 its alias "share", instead.
4117 *** Changes in GDB 7.8
4119 * New command line options
4122 This is an alias for the --data-directory option.
4124 * GDB supports printing and modifying of variable length automatic arrays
4125 as specified in ISO C99.
4127 * The ARM simulator now supports instruction level tracing
4128 with or without disassembly.
4132 GDB now has support for scripting using Guile. Whether this is
4133 available is determined at configure time.
4134 Guile version 2.0 or greater is required.
4135 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
4137 * New commands (for set/show, see "New options" below)
4141 Invoke CODE by passing it to the Guile interpreter.
4145 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
4147 info auto-load guile-scripts [regexp]
4148 Print the list of automatically loaded Guile scripts.
4150 * The source command is now capable of sourcing Guile scripts.
4151 This feature is dependent on the debugger being built with Guile support.
4155 set print symbol-loading (off|brief|full)
4156 show print symbol-loading
4157 Control whether to print informational messages when loading symbol
4158 information for a file. The default is "full", but when debugging
4159 programs with large numbers of shared libraries the amount of output
4160 becomes less useful.
4162 set guile print-stack (none|message|full)
4163 show guile print-stack
4164 Show a stack trace when an error is encountered in a Guile script.
4166 set auto-load guile-scripts (on|off)
4167 show auto-load guile-scripts
4168 Control auto-loading of Guile script files.
4170 maint ada set ignore-descriptive-types (on|off)
4171 maint ada show ignore-descriptive-types
4172 Control whether the debugger should ignore descriptive types in Ada
4173 programs. The default is not to ignore the descriptive types. See
4174 the user manual for more details on descriptive types and the intended
4175 usage of this option.
4177 set auto-connect-native-target
4179 Control whether GDB is allowed to automatically connect to the
4180 native target for the run, attach, etc. commands when not connected
4181 to any target yet. See also "target native" below.
4183 set record btrace replay-memory-access (read-only|read-write)
4184 show record btrace replay-memory-access
4185 Control what memory accesses are allowed during replay.
4187 maint set target-async (on|off)
4188 maint show target-async
4189 This controls whether GDB targets operate in synchronous or
4190 asynchronous mode. Normally the default is asynchronous, if it is
4191 available; but this can be changed to more easily debug problems
4192 occurring only in synchronous mode.
4194 set mi-async (on|off)
4196 Control whether MI asynchronous mode is preferred. This supersedes
4197 "set target-async" of previous GDB versions.
4199 * "set target-async" is deprecated as a CLI option and is now an alias
4200 for "set mi-async" (only puts MI into async mode).
4202 * Background execution commands (e.g., "c&", "s&", etc.) are now
4203 possible ``out of the box'' if the target supports them. Previously
4204 the user would need to explicitly enable the possibility with the
4205 "set target-async on" command.
4207 * New features in the GDB remote stub, GDBserver
4209 ** New option --debug-format=option1[,option2,...] allows one to add
4210 additional text to each output. At present only timestamps
4211 are supported: --debug-format=timestamps.
4212 Timestamps can also be turned on with the
4213 "monitor set debug-format timestamps" command from GDB.
4215 * The 'record instruction-history' command now starts counting instructions
4216 at one. This also affects the instruction ranges reported by the
4217 'record function-call-history' command when given the /i modifier.
4219 * The command 'record function-call-history' supports a new modifier '/c' to
4220 indent the function names based on their call stack depth.
4221 The fields for the '/i' and '/l' modifier have been reordered.
4222 The source line range is now prefixed with 'at'.
4223 The instruction range is now prefixed with 'inst'.
4224 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
4225 "record instruction-history" and "list" commands.
4227 * The ranges given as arguments to the 'record function-call-history' and
4228 'record instruction-history' commands are now inclusive.
4230 * The btrace record target now supports the 'record goto' command.
4231 For locations inside the execution trace, the back trace is computed
4232 based on the information stored in the execution trace.
4234 * The btrace record target supports limited reverse execution and replay.
4235 The target does not record data and therefore does not allow reading
4236 memory or registers.
4238 * The "catch syscall" command now works on s390*-linux* targets.
4240 * The "compare-sections" command is no longer specific to target
4241 remote. It now works with all targets.
4243 * All native targets are now consistently called "native".
4244 Consequently, the "target child", "target GNU", "target djgpp",
4245 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
4246 commands have been replaced with "target native". The QNX/NTO port
4247 leaves the "procfs" target in place and adds a "native" target for
4248 consistency with other ports. The impact on users should be minimal
4249 as these commands previously either threw an error, or were
4250 no-ops. The target's name is visible in the output of the following
4251 commands: "help target", "info target", "info files", "maint print
4254 * The "target native" command now connects to the native target. This
4255 can be used to launch native programs even when "set
4256 auto-connect-native-target" is set to off.
4258 * GDB now supports access to Intel MPX registers on GNU/Linux.
4260 * Support for Intel AVX-512 registers on GNU/Linux.
4261 Support displaying and modifying Intel AVX-512 registers
4262 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
4264 * New remote packets
4266 qXfer:btrace:read's annex
4267 The qXfer:btrace:read packet supports a new annex 'delta' to read
4268 branch trace incrementally.
4272 ** Valid Python operations on gdb.Value objects representing
4273 structs/classes invoke the corresponding overloaded operators if
4275 ** New `Xmethods' feature in the Python API. Xmethods are
4276 additional methods or replacements for existing methods of a C++
4277 class. This feature is useful for those cases where a method
4278 defined in C++ source code could be inlined or optimized out by
4279 the compiler, making it unavailable to GDB.
4282 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
4284 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
4285 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
4286 its alias "share", instead.
4288 * The commands "set remotebaud" and "show remotebaud" are no longer
4289 supported. Use "set serial baud" and "show serial baud" (respectively)
4294 ** A new option "-gdb-set mi-async" replaces "-gdb-set
4295 target-async". The latter is left as a deprecated alias of the
4296 former for backward compatibility. If the target supports it,
4297 CLI background execution commands are now always possible by
4298 default, independently of whether the frontend stated a
4299 preference for asynchronous execution with "-gdb-set mi-async".
4300 Previously "-gdb-set target-async off" affected both MI execution
4301 commands and CLI execution commands.
4303 *** Changes in GDB 7.7
4305 * Improved support for process record-replay and reverse debugging on
4306 arm*-linux* targets. Support for thumb32 and syscall instruction
4307 recording has been added.
4309 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
4311 * GDB now supports Fission DWP file format version 2.
4312 http://gcc.gnu.org/wiki/DebugFission
4314 * New convenience function "$_isvoid", to check whether an expression
4315 is void. A void expression is an expression where the type of the
4316 result is "void". For example, some convenience variables may be
4317 "void" when evaluated (e.g., "$_exitcode" before the execution of
4318 the program being debugged; or an undefined convenience variable).
4319 Another example, when calling a function whose return type is
4322 * The "maintenance print objfiles" command now takes an optional regexp.
4324 * The "catch syscall" command now works on arm*-linux* targets.
4326 * GDB now consistently shows "<not saved>" when printing values of
4327 registers the debug info indicates have not been saved in the frame
4328 and there's nowhere to retrieve them from
4329 (callee-saved/call-clobbered registers):
4334 (gdb) info registers rax
4337 Before, the former would print "<optimized out>", and the latter
4338 "*value not available*".
4340 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
4345 ** Frame filters and frame decorators have been added.
4346 ** Temporary breakpoints are now supported.
4347 ** Line tables representation has been added.
4348 ** New attribute 'parent_type' for gdb.Field objects.
4349 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
4350 ** New attribute 'name' for gdb.Type objects.
4354 Nios II ELF nios2*-*-elf
4355 Nios II GNU/Linux nios2*-*-linux
4356 Texas Instruments MSP430 msp430*-*-elf
4358 * Removed native configurations
4360 Support for these a.out NetBSD and OpenBSD obsolete configurations has
4361 been removed. ELF variants of these configurations are kept supported.
4363 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
4364 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
4365 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
4366 i[34567]86-*-openbsd3.[0-3]
4367 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
4368 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
4369 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
4373 Like "catch throw", but catches a re-thrown exception.
4374 maint check-psymtabs
4375 Renamed from old "maint check-symtabs".
4377 Perform consistency checks on symtabs.
4378 maint expand-symtabs
4379 Expand symtabs matching an optional regexp.
4382 Display the details of GDB configure-time options.
4384 maint set|show per-command
4385 maint set|show per-command space
4386 maint set|show per-command time
4387 maint set|show per-command symtab
4388 Enable display of per-command gdb resource usage.
4390 remove-symbol-file FILENAME
4391 remove-symbol-file -a ADDRESS
4392 Remove a symbol file added via add-symbol-file. The file to remove
4393 can be identified by its filename or by an address that lies within
4394 the boundaries of this symbol file in memory.
4397 info exceptions REGEXP
4398 Display the list of Ada exceptions defined in the program being
4399 debugged. If provided, only the exceptions whose names match REGEXP
4404 set debug symfile off|on
4406 Control display of debugging info regarding reading symbol files and
4407 symbol tables within those files
4409 set print raw frame-arguments
4410 show print raw frame-arguments
4411 Set/show whether to print frame arguments in raw mode,
4412 disregarding any defined pretty-printers.
4414 set remote trace-status-packet
4415 show remote trace-status-packet
4416 Set/show the use of remote protocol qTStatus packet.
4420 Control display of debugging messages related to Nios II targets.
4424 Control whether target-assisted range stepping is enabled.
4426 set startup-with-shell
4427 show startup-with-shell
4428 Specifies whether Unix child processes are started via a shell or
4433 Use the target memory cache for accesses to the code segment. This
4434 improves performance of remote debugging (particularly disassembly).
4436 * You can now use a literal value 'unlimited' for options that
4437 interpret 0 or -1 as meaning "unlimited". E.g., "set
4438 trace-buffer-size unlimited" is now an alias for "set
4439 trace-buffer-size -1" and "set height unlimited" is now an alias for
4442 * The "set debug symtab-create" debugging option of GDB has been changed to
4443 accept a verbosity level. 0 means "off", 1 provides basic debugging
4444 output, and values of 2 or greater provides more verbose output.
4446 * New command-line options
4448 Display the details of GDB configure-time options.
4450 * The command 'tsave' can now support new option '-ctf' to save trace
4451 buffer in Common Trace Format.
4453 * Newly installed $prefix/bin/gcore acts as a shell interface for the
4456 * GDB now implements the C++ 'typeid' operator.
4458 * The new convenience variable $_exception holds the exception being
4459 thrown or caught at an exception-related catchpoint.
4461 * The exception-related catchpoints, like "catch throw", now accept a
4462 regular expression which can be used to filter exceptions by type.
4464 * The new convenience variable $_exitsignal is automatically set to
4465 the terminating signal number when the program being debugged dies
4466 due to an uncaught signal.
4470 ** All MI commands now accept an optional "--language" option.
4471 Support for this feature can be verified by using the "-list-features"
4472 command, which should contain "language-option".
4474 ** The new command -info-gdb-mi-command allows the user to determine
4475 whether a GDB/MI command is supported or not.
4477 ** The "^error" result record returned when trying to execute an undefined
4478 GDB/MI command now provides a variable named "code" whose content is the
4479 "undefined-command" error code. Support for this feature can be verified
4480 by using the "-list-features" command, which should contain
4481 "undefined-command-error-code".
4483 ** The -trace-save MI command can optionally save trace buffer in Common
4486 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
4488 ** The command -data-list-register-values now accepts an optional
4489 "--skip-unavailable" option. When used, only the available registers
4492 ** The new command -trace-frame-collected dumps collected variables,
4493 computed expressions, tvars, memory and registers in a traceframe.
4495 ** The commands -stack-list-locals, -stack-list-arguments and
4496 -stack-list-variables now accept an option "--skip-unavailable".
4497 When used, only the available locals or arguments are displayed.
4499 ** The -exec-run command now accepts an optional "--start" option.
4500 When used, the command follows the same semantics as the "start"
4501 command, stopping the program's execution at the start of its
4502 main subprogram. Support for this feature can be verified using
4503 the "-list-features" command, which should contain
4504 "exec-run-start-option".
4506 ** The new commands -catch-assert and -catch-exceptions insert
4507 catchpoints stopping the program when Ada exceptions are raised.
4509 ** The new command -info-ada-exceptions provides the equivalent of
4510 the new "info exceptions" command.
4512 * New system-wide configuration scripts
4513 A GDB installation now provides scripts suitable for use as system-wide
4514 configuration scripts for the following systems:
4518 * GDB now supports target-assigned range stepping with remote targets.
4519 This improves the performance of stepping source lines by reducing
4520 the number of control packets from/to GDB. See "New remote packets"
4523 * GDB now understands the element 'tvar' in the XML traceframe info.
4524 It has the id of the collected trace state variables.
4526 * On S/390 targets that provide the transactional-execution feature,
4527 the program interruption transaction diagnostic block (TDB) is now
4528 represented as a number of additional "registers" in GDB.
4530 * New remote packets
4534 The vCont packet supports a new 'r' action, that tells the remote
4535 stub to step through an address range itself, without GDB
4536 involvemement at each single-step.
4538 qXfer:libraries-svr4:read's annex
4539 The previously unused annex of the qXfer:libraries-svr4:read packet
4540 is now used to support passing an argument list. The remote stub
4541 reports support for this argument list to GDB's qSupported query.
4542 The defined arguments are "start" and "prev", used to reduce work
4543 necessary for library list updating, resulting in significant
4546 * New features in the GDB remote stub, GDBserver
4548 ** GDBserver now supports target-assisted range stepping. Currently
4549 enabled on x86/x86_64 GNU/Linux targets.
4551 ** GDBserver now adds element 'tvar' in the XML in the reply to
4552 'qXfer:traceframe-info:read'. It has the id of the collected
4553 trace state variables.
4555 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
4558 * New 'z' formatter for printing and examining memory, this displays the
4559 value as hexadecimal zero padded on the left to the size of the type.
4561 * GDB can now use Windows x64 unwinding data.
4563 * The "set remotebaud" command has been replaced by "set serial baud".
4564 Similarly, "show remotebaud" has been replaced by "show serial baud".
4565 The "set remotebaud" and "show remotebaud" commands are still available
4566 to provide backward compatibility with older versions of GDB.
4568 *** Changes in GDB 7.6
4570 * Target record has been renamed to record-full.
4571 Record/replay is now enabled with the "record full" command.
4572 This also affects settings that are associated with full record/replay
4573 that have been moved from "set/show record" to "set/show record full":
4575 set|show record full insn-number-max
4576 set|show record full stop-at-limit
4577 set|show record full memory-query
4579 * A new record target "record-btrace" has been added. The new target
4580 uses hardware support to record the control-flow of a process. It
4581 does not support replaying the execution, but it implements the
4582 below new commands for investigating the recorded execution log.
4583 This new recording method can be enabled using:
4587 The "record-btrace" target is only available on Intel Atom processors
4588 and requires a Linux kernel 2.6.32 or later.
4590 * Two new commands have been added for record/replay to give information
4591 about the recorded execution without having to replay the execution.
4592 The commands are only supported by "record btrace".
4594 record instruction-history prints the execution history at
4595 instruction granularity
4597 record function-call-history prints the execution history at
4598 function granularity
4600 * New native configurations
4602 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
4603 FreeBSD/powerpc powerpc*-*-freebsd
4604 x86_64/Cygwin x86_64-*-cygwin*
4605 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
4609 ARM AArch64 aarch64*-*-elf
4610 ARM AArch64 GNU/Linux aarch64*-*-linux
4611 Lynx 178 PowerPC powerpc-*-lynx*178
4612 x86_64/Cygwin x86_64-*-cygwin*
4613 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
4615 * If the configured location of system.gdbinit file (as given by the
4616 --with-system-gdbinit option at configure time) is in the
4617 data-directory (as specified by --with-gdb-datadir at configure
4618 time) or in one of its subdirectories, then GDB will look for the
4619 system-wide init file in the directory specified by the
4620 --data-directory command-line option.
4622 * New command line options:
4624 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
4625 other initialization files, unlike -nx which disables all of them.
4627 * Removed command line options
4629 -epoch This was used by the gdb mode in Epoch, an ancient fork of
4632 * The 'ptype' and 'whatis' commands now accept an argument to control
4635 * 'info proc' now works on some core files.
4639 ** Vectors can be created with gdb.Type.vector.
4641 ** Python's atexit.register now works in GDB.
4643 ** Types can be pretty-printed via a Python API.
4645 ** Python 3 is now supported (in addition to Python 2.4 or later)
4647 ** New class gdb.Architecture exposes GDB's internal representation
4648 of architecture in the Python API.
4650 ** New method Frame.architecture returns the gdb.Architecture object
4651 corresponding to the frame's architecture.
4653 * New Python-based convenience functions:
4655 ** $_memeq(buf1, buf2, length)
4656 ** $_streq(str1, str2)
4658 ** $_regex(str, regex)
4660 * The 'cd' command now defaults to using '~' (the home directory) if not
4663 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
4664 default for GCC since November 2000.
4666 * The command 'forward-search' can now be abbreviated as 'fo'.
4668 * The command 'info tracepoints' can now display 'installed on target'
4669 or 'not installed on target' for each non-pending location of tracepoint.
4671 * New configure options
4673 --enable-libmcheck/--disable-libmcheck
4674 By default, development versions are built with -lmcheck on hosts
4675 that support it, in order to help track memory corruption issues.
4676 Release versions, on the other hand, are built without -lmcheck
4677 by default. The --enable-libmcheck/--disable-libmcheck configure
4678 options allow the user to override that default.
4679 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
4680 This configure option allows the user to build GDB with
4681 libbabeltrace using which GDB can read Common Trace Format data.
4683 * New commands (for set/show, see "New options" below)
4686 Catch signals. This is similar to "handle", but allows commands and
4687 conditions to be attached.
4690 List the BFDs known to GDB.
4692 python-interactive [command]
4694 Start a Python interactive prompt, or evaluate the optional command
4695 and print the result of expressions.
4698 "py" is a new alias for "python".
4700 enable type-printer [name]...
4701 disable type-printer [name]...
4702 Enable or disable type printers.
4706 ** For the Renesas Super-H architecture, the "regs" command has been removed
4707 (has been deprecated in GDB 7.5), and "info all-registers" should be used
4712 set print type methods (on|off)
4713 show print type methods
4714 Control whether method declarations are displayed by "ptype".
4715 The default is to show them.
4717 set print type typedefs (on|off)
4718 show print type typedefs
4719 Control whether typedef definitions are displayed by "ptype".
4720 The default is to show them.
4722 set filename-display basename|relative|absolute
4723 show filename-display
4724 Control the way in which filenames is displayed.
4725 The default is "relative", which preserves previous behavior.
4727 set trace-buffer-size
4728 show trace-buffer-size
4729 Request target to change the size of trace buffer.
4731 set remote trace-buffer-size-packet auto|on|off
4732 show remote trace-buffer-size-packet
4733 Control the use of the remote protocol `QTBuffer:size' packet.
4737 Control display of debugging messages related to ARM AArch64.
4740 set debug coff-pe-read
4741 show debug coff-pe-read
4742 Control display of debugging messages related to reading of COFF/PE
4747 Control display of debugging messages related to Mach-O symbols
4750 set debug notification
4751 show debug notification
4752 Control display of debugging info for async remote notification.
4756 ** Command parameter changes are now notified using new async record
4757 "=cmd-param-changed".
4758 ** Trace frame changes caused by command "tfind" are now notified using
4759 new async record "=traceframe-changed".
4760 ** The creation, deletion and modification of trace state variables
4761 are now notified using new async records "=tsv-created",
4762 "=tsv-deleted" and "=tsv-modified".
4763 ** The start and stop of process record are now notified using new
4764 async record "=record-started" and "=record-stopped".
4765 ** Memory changes are now notified using new async record
4767 ** The data-disassemble command response will include a "fullname" field
4768 containing the absolute file name when source has been requested.
4769 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
4770 command, to allow pattern filling of memory areas.
4771 ** New commands "-catch-load"/"-catch-unload" added for intercepting
4772 library load/unload events.
4773 ** The response to breakpoint commands and breakpoint async records
4774 includes an "installed" field containing a boolean state about each
4775 non-pending tracepoint location is whether installed on target or not.
4776 ** Output of the "-trace-status" command includes a "trace-file" field
4777 containing the name of the trace file being examined. This field is
4778 optional, and only present when examining a trace file.
4779 ** The "fullname" field is now always present along with the "file" field,
4780 even if the file cannot be found by GDB.
4782 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4783 You must have the LZMA library available when configuring GDB for this
4784 feature to be enabled. For more information, see:
4785 http://fedoraproject.org/wiki/Features/MiniDebugInfo
4787 * New remote packets
4790 Set the size of trace buffer. The remote stub reports support for this
4791 packet to gdb's qSupported query.
4794 Enable Branch Trace Store (BTS)-based branch tracing for the current
4795 thread. The remote stub reports support for this packet to gdb's
4799 Disable branch tracing for the current thread. The remote stub reports
4800 support for this packet to gdb's qSupported query.
4803 Read the traced branches for the current thread. The remote stub
4804 reports support for this packet to gdb's qSupported query.
4806 *** Changes in GDB 7.5
4808 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
4809 for more x32 ABI info.
4811 * GDB now supports access to MIPS DSP registers on Linux targets.
4813 * GDB now supports debugging microMIPS binaries.
4815 * The "info os" command on GNU/Linux can now display information on
4816 several new classes of objects managed by the operating system:
4817 "info os procgroups" lists process groups
4818 "info os files" lists file descriptors
4819 "info os sockets" lists internet-domain sockets
4820 "info os shm" lists shared-memory regions
4821 "info os semaphores" lists semaphores
4822 "info os msg" lists message queues
4823 "info os modules" lists loaded kernel modules
4825 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
4826 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
4827 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4828 options and inspect the probe arguments using the new $_probe_arg family
4829 of convenience variables. You can obtain more information about SystemTap
4830 in <http://sourceware.org/systemtap/>.
4832 * GDB now supports reversible debugging on ARM, it allows you to
4833 debug basic ARM and THUMB instructions, and provides
4834 record/replay support.
4836 * The option "symbol-reloading" has been deleted as it is no longer used.
4840 ** GDB commands implemented in Python can now be put in command class
4843 ** The "maint set python print-stack on|off" is now deleted.
4845 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4846 apply "flag enum"-style pretty-printing to any enum.
4848 ** gdb.lookup_symbol can now work when there is no current frame.
4850 ** gdb.Symbol now has a 'line' attribute, holding the line number in
4851 the source at which the symbol was defined.
4853 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4854 method 'value'. The former indicates whether the symbol needs a
4855 frame in order to compute its value, and the latter computes the
4858 ** A new method 'referenced_value' on gdb.Value objects which can
4859 dereference pointer as well as C++ reference values.
4861 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4862 which return the global and static blocks (as gdb.Block objects),
4863 of the underlying symbol table, respectively.
4865 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4866 object associated with a PC value.
4868 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4869 of the address range occupied by code for the current source line.
4871 * Go language support.
4872 GDB now supports debugging programs written in the Go programming
4875 * GDBserver now supports stdio connections.
4876 E.g. (gdb) target remote | ssh myhost gdbserver - hello
4878 * The binary "gdbtui" can no longer be built or installed.
4879 Use "gdb -tui" instead.
4881 * GDB will now print "flag" enums specially. A flag enum is one where
4882 all the enumerator values have no bits in common when pairwise
4883 "and"ed. When printing a value whose type is a flag enum, GDB will
4884 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4885 (gdb) print (enum E) 3
4888 * The filename part of a linespec will now match trailing components
4889 of a source file name. For example, "break gcc/expr.c:1000" will
4890 now set a breakpoint in build/gcc/expr.c, but not
4891 build/libcpp/expr.c.
4893 * The "info proc" and "generate-core-file" commands will now also
4894 work on remote targets connected to GDBserver on Linux.
4896 * The command "info catch" has been removed. It has been disabled
4897 since December 2007.
4899 * The "catch exception" and "catch assert" commands now accept
4900 a condition at the end of the command, much like the "break"
4901 command does. For instance:
4903 (gdb) catch exception Constraint_Error if Barrier = True
4905 Previously, it was possible to add a condition to such catchpoints,
4906 but it had to be done as a second step, after the catchpoint had been
4907 created, using the "condition" command.
4909 * The "info static-tracepoint-marker" command will now also work on
4910 native Linux targets with in-process agent.
4912 * GDB can now set breakpoints on inlined functions.
4914 * The .gdb_index section has been updated to include symbols for
4915 inlined functions. GDB will ignore older .gdb_index sections by
4916 default, which could cause symbol files to be loaded more slowly
4917 until their .gdb_index sections can be recreated. The new command
4918 "set use-deprecated-index-sections on" will cause GDB to use any older
4919 .gdb_index sections it finds. This will restore performance, but the
4920 ability to set breakpoints on inlined functions will be lost in symbol
4921 files with older .gdb_index sections.
4923 The .gdb_index section has also been updated to record more information
4924 about each symbol. This speeds up the "info variables", "info functions"
4925 and "info types" commands when used with programs having the .gdb_index
4926 section, as well as speeding up debugging with shared libraries using
4927 the .gdb_index section.
4929 * Ada support for GDB/MI Variable Objects has been added.
4931 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4936 ** New command -info-os is the MI equivalent of "info os".
4938 ** Output logs ("set logging" and related) now include MI output.
4942 ** "set use-deprecated-index-sections on|off"
4943 "show use-deprecated-index-sections on|off"
4944 Controls the use of deprecated .gdb_index sections.
4946 ** "catch load" and "catch unload" can be used to stop when a shared
4947 library is loaded or unloaded, respectively.
4949 ** "enable count" can be used to auto-disable a breakpoint after
4952 ** "info vtbl" can be used to show the virtual method tables for
4953 C++ and Java objects.
4955 ** "explore" and its sub commands "explore value" and "explore type"
4956 can be used to recursively explore values and types of
4957 expressions. These commands are available only if GDB is
4958 configured with '--with-python'.
4960 ** "info auto-load" shows status of all kinds of auto-loaded files,
4961 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4962 sequences of commands files, "info auto-load python-scripts"
4963 shows status of auto-loading Python script files,
4964 "info auto-load local-gdbinit" shows status of loading init file
4965 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4966 status of inferior specific thread debugging shared library loading.
4968 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4969 and "show auto-load-scripts" commands have been deprecated, use their
4970 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4971 and "show auto-load python-scripts" counterparts instead.
4973 ** "dprintf location,format,args..." creates a dynamic printf, which
4974 is basically a breakpoint that does a printf and immediately
4975 resumes your program's execution, so it is like a printf that you
4976 can insert dynamically at runtime instead of at compile time.
4978 ** "set print symbol"
4980 Controls whether GDB attempts to display the symbol, if any,
4981 corresponding to addresses it prints. This defaults to "on", but
4982 you can set it to "off" to restore GDB's previous behavior.
4984 * Deprecated commands
4986 ** For the Renesas Super-H architecture, the "regs" command has been
4987 deprecated, and "info all-registers" should be used instead.
4991 Renesas RL78 rl78-*-elf
4992 HP OpenVMS ia64 ia64-hp-openvms*
4994 * GDBserver supports evaluation of breakpoint conditions. When
4995 support is advertised by GDBserver, GDB may be told to send the
4996 breakpoint conditions in bytecode form to GDBserver. GDBserver
4997 will only report the breakpoint trigger to GDB when its condition
5002 set mips compression
5003 show mips compression
5004 Select the compressed ISA encoding used in functions that have no symbol
5005 information available. The encoding can be set to either of:
5008 and is updated automatically from ELF file flags if available.
5010 set breakpoint condition-evaluation
5011 show breakpoint condition-evaluation
5012 Control whether breakpoint conditions are evaluated by GDB ("host") or by
5013 GDBserver ("target"). Default option "auto" chooses the most efficient
5015 This option can improve debugger efficiency depending on the speed of the
5019 Disable auto-loading globally.
5022 Show auto-loading setting of all kinds of auto-loaded files.
5024 set auto-load gdb-scripts on|off
5025 show auto-load gdb-scripts
5026 Control auto-loading of GDB canned sequences of commands files.
5028 set auto-load python-scripts on|off
5029 show auto-load python-scripts
5030 Control auto-loading of Python script files.
5032 set auto-load local-gdbinit on|off
5033 show auto-load local-gdbinit
5034 Control loading of init file (.gdbinit) from current directory.
5036 set auto-load libthread-db on|off
5037 show auto-load libthread-db
5038 Control auto-loading of inferior specific thread debugging shared library.
5040 set auto-load scripts-directory <dir1>[:<dir2>...]
5041 show auto-load scripts-directory
5042 Set a list of directories from which to load auto-loaded scripts.
5043 Automatically loaded Python scripts and GDB scripts are located in one
5044 of the directories listed by this option.
5045 The delimiter (':' above) may differ according to the host platform.
5047 set auto-load safe-path <dir1>[:<dir2>...]
5048 show auto-load safe-path
5049 Set a list of directories from which it is safe to auto-load files.
5050 The delimiter (':' above) may differ according to the host platform.
5052 set debug auto-load on|off
5053 show debug auto-load
5054 Control display of debugging info for auto-loading the files above.
5056 set dprintf-style gdb|call|agent
5058 Control the way in which a dynamic printf is performed; "gdb"
5059 requests a GDB printf command, while "call" causes dprintf to call a
5060 function in the inferior. "agent" requests that the target agent
5061 (such as GDBserver) do the printing.
5063 set dprintf-function <expr>
5064 show dprintf-function
5065 set dprintf-channel <expr>
5066 show dprintf-channel
5067 Set the function and optional first argument to the call when using
5068 the "call" style of dynamic printf.
5070 set disconnected-dprintf on|off
5071 show disconnected-dprintf
5072 Control whether agent-style dynamic printfs continue to be in effect
5073 after GDB disconnects.
5075 * New configure options
5077 --with-auto-load-dir
5078 Configure default value for the 'set auto-load scripts-directory'
5079 setting above. It defaults to '$debugdir:$datadir/auto-load',
5080 $debugdir representing global debugging info directories (available
5081 via 'show debug-file-directory') and $datadir representing GDB's data
5082 directory (available via 'show data-directory').
5084 --with-auto-load-safe-path
5085 Configure default value for the 'set auto-load safe-path' setting
5086 above. It defaults to the --with-auto-load-dir setting.
5088 --without-auto-load-safe-path
5089 Set 'set auto-load safe-path' to '/', effectively disabling this
5092 * New remote packets
5094 z0/z1 conditional breakpoints extension
5096 The z0/z1 breakpoint insertion packets have been extended to carry
5097 a list of conditional expressions over to the remote stub depending on the
5098 condition evaluation mode. The use of this extension can be controlled
5099 via the "set remote conditional-breakpoints-packet" command.
5103 Specify the signals which the remote stub may pass to the debugged
5104 program without GDB involvement.
5106 * New command line options
5108 --init-command=FILE, -ix Like --command, -x but execute it
5109 before loading inferior.
5110 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
5111 execute it before loading inferior.
5113 *** Changes in GDB 7.4
5115 * GDB now handles ambiguous linespecs more consistently; the existing
5116 FILE:LINE support has been expanded to other types of linespecs. A
5117 breakpoint will now be set on all matching locations in all
5118 inferiors, and locations will be added or removed according to
5121 * GDB now allows you to skip uninteresting functions and files when
5122 stepping with the "skip function" and "skip file" commands.
5124 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
5125 and "show remote hardware-watchpoint-length-limit". These allows to
5126 set or show the maximum length limit (in bytes) of a remote
5127 target hardware watchpoint.
5129 This allows e.g. to use "unlimited" hardware watchpoints with the
5130 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
5131 watchpoints are slower than real hardware watchpoints but are
5132 significantly faster than gdb software watchpoints.
5136 ** The register_pretty_printer function in module gdb.printing now takes
5137 an optional `replace' argument. If True, the new printer replaces any
5140 ** The "maint set python print-stack on|off" command has been
5141 deprecated and will be deleted in GDB 7.5.
5142 A new command: "set python print-stack none|full|message" has
5143 replaced it. Additionally, the default for "print-stack" is
5144 now "message", which just prints the error message without
5147 ** A prompt substitution hook (prompt_hook) is now available to the
5150 ** A new Python module, gdb.prompt has been added to the GDB Python
5151 modules library. This module provides functionality for
5152 escape sequences in prompts (used by set/show
5153 extended-prompt). These escape sequences are replaced by their
5154 corresponding value.
5156 ** Python commands and convenience-functions located in
5157 'data-directory'/python/gdb/command and
5158 'data-directory'/python/gdb/function are now automatically loaded
5161 ** Blocks now provide four new attributes. global_block and
5162 static_block will return the global and static blocks
5163 respectively. is_static and is_global are boolean attributes
5164 that indicate if the block is one of those two types.
5166 ** Symbols now provide the "type" attribute, the type of the symbol.
5168 ** The "gdb.breakpoint" function has been deprecated in favor of
5171 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
5172 of a function. This class is based on the "finish" command
5173 available in the CLI.
5175 ** Type objects for struct and union types now allow access to
5176 the fields using standard Python dictionary (mapping) methods.
5177 For example, "some_type['myfield']" now works, as does
5178 "some_type.items()".
5180 ** A new event "gdb.new_objfile" has been added, triggered by loading a
5183 ** A new function, "deep_items" has been added to the gdb.types
5184 module in the GDB Python modules library. This function returns
5185 an iterator over the fields of a struct or union type. Unlike
5186 the standard Python "iteritems" method, it will recursively traverse
5187 any anonymous fields.
5191 ** "*stopped" events can report several new "reason"s, such as
5194 ** Breakpoint changes are now notified using new async records, like
5195 "=breakpoint-modified".
5197 ** New command -ada-task-info.
5199 * libthread-db-search-path now supports two special values: $sdir and $pdir.
5200 $sdir specifies the default system locations of shared libraries.
5201 $pdir specifies the directory where the libpthread used by the application
5204 GDB no longer looks in $sdir and $pdir after it has searched the directories
5205 mentioned in libthread-db-search-path. If you want to search those
5206 directories, they must be specified in libthread-db-search-path.
5207 The default value of libthread-db-search-path on GNU/Linux and Solaris
5208 systems is now "$sdir:$pdir".
5210 $pdir is not supported by gdbserver, it is currently ignored.
5211 $sdir is supported by gdbserver.
5213 * New configure option --with-iconv-bin.
5214 When using the internationalization support like the one in the GNU C
5215 library, GDB will invoke the "iconv" program to get a list of supported
5216 character sets. If this program lives in a non-standard location, one can
5217 use this option to specify where to find it.
5219 * When natively debugging programs on PowerPC BookE processors running
5220 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
5221 watchpoints, which specify a mask in addition to an address to watch.
5222 The mask specifies that some bits of an address (the bits which are
5223 reset in the mask) should be ignored when matching the address accessed
5224 by the inferior against the watchpoint address. See the "PowerPC Embedded"
5225 section in the user manual for more details.
5227 * The new option --once causes GDBserver to stop listening for connections once
5228 the first connection is made. The listening port used by GDBserver will
5229 become available after that.
5231 * New commands "info macros" and "alias" have been added.
5233 * New function parameters suffix @entry specifies value of function parameter
5234 at the time the function got called. Entry values are available only since
5240 "!" is now an alias of the "shell" command.
5241 Note that no space is needed between "!" and SHELL COMMAND.
5245 watch EXPRESSION mask MASK_VALUE
5246 The watch command now supports the mask argument which allows creation
5247 of masked watchpoints, if the current architecture supports this feature.
5249 info auto-load-scripts [REGEXP]
5250 This command was formerly named "maintenance print section-scripts".
5251 It is now generally useful and is no longer a maintenance-only command.
5253 info macro [-all] [--] MACRO
5254 The info macro command has new options `-all' and `--'. The first for
5255 printing all definitions of a macro. The second for explicitly specifying
5256 the end of arguments and the beginning of the macro name in case the macro
5257 name starts with a hyphen.
5259 collect[/s] EXPRESSIONS
5260 The tracepoint collect command now takes an optional modifier "/s"
5261 that directs it to dereference pointer-to-character types and
5262 collect the bytes of memory up to a zero byte. The behavior is
5263 similar to what you see when you use the regular print command on a
5264 string. An optional integer following the "/s" sets a bound on the
5265 number of bytes that will be collected.
5268 The trace start command now interprets any supplied arguments as a
5269 note to be recorded with the trace run, with an effect similar to
5270 setting the variable trace-notes.
5273 The trace stop command now interprets any arguments as a note to be
5274 mentioned along with the tstatus report that the trace was stopped
5275 with a command. The effect is similar to setting the variable
5278 * Tracepoints can now be enabled and disabled at any time after a trace
5279 experiment has been started using the standard "enable" and "disable"
5280 commands. It is now possible to start a trace experiment with no enabled
5281 tracepoints; GDB will display a warning, but will allow the experiment to
5282 begin, assuming that tracepoints will be enabled as needed while the trace
5285 * Fast tracepoints on 32-bit x86-architectures can now be placed at
5286 locations with 4-byte instructions, when they were previously
5287 limited to locations with instructions of 5 bytes or longer.
5291 set debug dwarf2-read
5292 show debug dwarf2-read
5293 Turns on or off display of debugging messages related to reading
5294 DWARF debug info. The default is off.
5296 set debug symtab-create
5297 show debug symtab-create
5298 Turns on or off display of debugging messages related to symbol table
5299 creation. The default is off.
5302 show extended-prompt
5303 Set the GDB prompt, and allow escape sequences to be inserted to
5304 display miscellaneous information (see 'help set extended-prompt'
5305 for the list of sequences). This prompt (and any information
5306 accessed through the escape sequences) is updated every time the
5307 prompt is displayed.
5309 set print entry-values (both|compact|default|if-needed|no|only|preferred)
5310 show print entry-values
5311 Set printing of frame argument values at function entry. In some cases
5312 GDB can determine the value of function argument which was passed by the
5313 function caller, even if the value was modified inside the called function.
5315 set debug entry-values
5316 show debug entry-values
5317 Control display of debugging info for determining frame argument values at
5318 function entry and virtual tail call frames.
5320 set basenames-may-differ
5321 show basenames-may-differ
5322 Set whether a source file may have multiple base names.
5323 (A "base name" is the name of a file with the directory part removed.
5324 Example: The base name of "/home/user/hello.c" is "hello.c".)
5325 If set, GDB will canonicalize file names (e.g., expand symlinks)
5326 before comparing them. Canonicalization is an expensive operation,
5327 but it allows the same file be known by more than one base name.
5328 If not set (the default), all source files are assumed to have just
5329 one base name, and gdb will do file name comparisons more efficiently.
5335 Set a user name and notes for the current and any future trace runs.
5336 This is useful for long-running and/or disconnected traces, to
5337 inform others (or yourself) as to who is running the trace, supply
5338 contact information, or otherwise explain what is going on.
5340 set trace-stop-notes
5341 show trace-stop-notes
5342 Set a note attached to the trace run, that is displayed when the
5343 trace has been stopped by a tstop command. This is useful for
5344 instance as an explanation, if you are stopping a trace run that was
5345 started by someone else.
5347 * New remote packets
5351 Dynamically enable a tracepoint in a started trace experiment.
5355 Dynamically disable a tracepoint in a started trace experiment.
5359 Set the user and notes of the trace run.
5363 Query the current status of a tracepoint.
5367 Query the minimum length of instruction at which a fast tracepoint may
5370 * Dcache size (number of lines) and line-size are now runtime-configurable
5371 via "set dcache line" and "set dcache line-size" commands.
5375 Texas Instruments TMS320C6x tic6x-*-*
5379 Renesas RL78 rl78-*-elf
5381 *** Changes in GDB 7.3.1
5383 * The build failure for NetBSD and OpenBSD targets have now been fixed.
5385 *** Changes in GDB 7.3
5387 * GDB has a new command: "thread find [REGEXP]".
5388 It finds the thread id whose name, target id, or thread extra info
5389 matches the given regular expression.
5391 * The "catch syscall" command now works on mips*-linux* targets.
5393 * The -data-disassemble MI command now supports modes 2 and 3 for
5394 dumping the instruction opcodes.
5396 * New command line options
5398 -data-directory DIR Specify DIR as the "data-directory".
5399 This is mostly for testing purposes.
5401 * The "maint set python auto-load on|off" command has been renamed to
5402 "set auto-load-scripts on|off".
5404 * GDB has a new command: "set directories".
5405 It is like the "dir" command except that it replaces the
5406 source path list instead of augmenting it.
5408 * GDB now understands thread names.
5410 On GNU/Linux, "info threads" will display the thread name as set by
5411 prctl or pthread_setname_np.
5413 There is also a new command, "thread name", which can be used to
5414 assign a name internally for GDB to display.
5417 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
5418 has been integrated into GDB.
5422 ** The function gdb.Write now accepts an optional keyword 'stream'.
5423 This keyword, when provided, will direct the output to either
5424 stdout, stderr, or GDB's logging output.
5426 ** Parameters can now be be sub-classed in Python, and in particular
5427 you may implement the get_set_doc and get_show_doc functions.
5428 This improves how Parameter set/show documentation is processed
5429 and allows for more dynamic content.
5431 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
5432 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
5433 have an is_valid method.
5435 ** Breakpoints can now be sub-classed in Python, and in particular
5436 you may implement a 'stop' function that is executed each time
5437 the inferior reaches that breakpoint.
5439 ** New function gdb.lookup_global_symbol looks up a global symbol.
5441 ** GDB values in Python are now callable if the value represents a
5442 function. For example, if 'some_value' represents a function that
5443 takes two integer parameters and returns a value, you can call
5444 that function like so:
5446 result = some_value (10,20)
5448 ** Module gdb.types has been added.
5449 It contains a collection of utilities for working with gdb.Types objects:
5450 get_basic_type, has_field, make_enum_dict.
5452 ** Module gdb.printing has been added.
5453 It contains utilities for writing and registering pretty-printers.
5454 New classes: PrettyPrinter, SubPrettyPrinter,
5455 RegexpCollectionPrettyPrinter.
5456 New function: register_pretty_printer.
5458 ** New commands "info pretty-printers", "enable pretty-printer" and
5459 "disable pretty-printer" have been added.
5461 ** gdb.parameter("directories") is now available.
5463 ** New function gdb.newest_frame returns the newest frame in the
5466 ** The gdb.InferiorThread class has a new "name" attribute. This
5467 holds the thread's name.
5469 ** Python Support for Inferior events.
5470 Python scripts can add observers to be notified of events
5471 occurring in the process being debugged.
5472 The following events are currently supported:
5473 - gdb.events.cont Continue event.
5474 - gdb.events.exited Inferior exited event.
5475 - gdb.events.stop Signal received, and Breakpoint hit events.
5479 ** GDB now puts template parameters in scope when debugging in an
5480 instantiation. For example, if you have:
5482 template<int X> int func (void) { return X; }
5484 then if you step into func<5>, "print X" will show "5". This
5485 feature requires proper debuginfo support from the compiler; it
5486 was added to GCC 4.5.
5488 ** The motion commands "next", "finish", "until", and "advance" now
5489 work better when exceptions are thrown. In particular, GDB will
5490 no longer lose control of the inferior; instead, the GDB will
5491 stop the inferior at the point at which the exception is caught.
5492 This functionality requires a change in the exception handling
5493 code that was introduced in GCC 4.5.
5495 * GDB now follows GCC's rules on accessing volatile objects when
5496 reading or writing target state during expression evaluation.
5497 One notable difference to prior behavior is that "print x = 0"
5498 no longer generates a read of x; the value of the assignment is
5499 now always taken directly from the value being assigned.
5501 * GDB now has some support for using labels in the program's source in
5502 linespecs. For instance, you can use "advance label" to continue
5503 execution to a label.
5505 * GDB now has support for reading and writing a new .gdb_index
5506 section. This section holds a fast index of DWARF debugging
5507 information and can be used to greatly speed up GDB startup and
5508 operation. See the documentation for `save gdb-index' for details.
5510 * The "watch" command now accepts an optional "-location" argument.
5511 When used, this causes GDB to watch the memory referred to by the
5512 expression. Such a watchpoint is never deleted due to it going out
5515 * GDB now supports thread debugging of core dumps on GNU/Linux.
5517 GDB now activates thread debugging using the libthread_db library
5518 when debugging GNU/Linux core dumps, similarly to when debugging
5519 live processes. As a result, when debugging a core dump file, GDB
5520 is now able to display pthread_t ids of threads. For example, "info
5521 threads" shows the same output as when debugging the process when it
5522 was live. In earlier releases, you'd see something like this:
5525 * 1 LWP 6780 main () at main.c:10
5527 While now you see this:
5530 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
5532 It is also now possible to inspect TLS variables when debugging core
5535 When debugging a core dump generated on a machine other than the one
5536 used to run GDB, you may need to point GDB at the correct
5537 libthread_db library with the "set libthread-db-search-path"
5538 command. See the user manual for more details on this command.
5540 * When natively debugging programs on PowerPC BookE processors running
5541 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
5542 which stop execution of the inferior whenever it executes an instruction
5543 at any address within the specified range. See the "PowerPC Embedded"
5544 section in the user manual for more details.
5546 * New features in the GDB remote stub, GDBserver
5548 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
5549 and i686 LynxOS (version 5.x).
5551 ** GDBserver is now supported on Blackfin Linux.
5553 * New native configurations
5555 ia64 HP-UX ia64-*-hpux*
5559 Analog Devices, Inc. Blackfin Processor bfin-*
5561 * Ada task switching is now supported on sparc-elf targets when
5562 debugging a program using the Ravenscar Profile. For more information,
5563 see the "Tasking Support when using the Ravenscar Profile" section
5564 in the GDB user manual.
5566 * Guile support was removed.
5568 * New features in the GNU simulator
5570 ** The --map-info flag lists all known core mappings.
5572 ** CFI flashes may be simulated via the "cfi" device.
5574 *** Changes in GDB 7.2
5576 * Shared library support for remote targets by default
5578 When GDB is configured for a generic, non-OS specific target, like
5579 for example, --target=arm-eabi or one of the many *-*-elf targets,
5580 GDB now queries remote stubs for loaded shared libraries using the
5581 `qXfer:libraries:read' packet. Previously, shared library support
5582 was always disabled for such configurations.
5586 ** Argument Dependent Lookup (ADL)
5588 In C++ ADL lookup directs function search to the namespaces of its
5589 arguments even if the namespace has not been imported.
5599 Here the compiler will search for `foo' in the namespace of 'b'
5600 and find A::foo. GDB now supports this. This construct is commonly
5601 used in the Standard Template Library for operators.
5603 ** Improved User Defined Operator Support
5605 In addition to member operators, GDB now supports lookup of operators
5606 defined in a namespace and imported with a `using' directive, operators
5607 defined in the global scope, operators imported implicitly from an
5608 anonymous namespace, and the ADL operators mentioned in the previous
5610 GDB now also supports proper overload resolution for all the previously
5611 mentioned flavors of operators.
5613 ** static const class members
5615 Printing of static const class members that are initialized in the
5616 class definition has been fixed.
5618 * Windows Thread Information Block access.
5620 On Windows targets, GDB now supports displaying the Windows Thread
5621 Information Block (TIB) structure. This structure is visible either
5622 by using the new command `info w32 thread-information-block' or, by
5623 dereferencing the new convenience variable named `$_tlb', a
5624 thread-specific pointer to the TIB. This feature is also supported
5625 when remote debugging using GDBserver.
5627 * Static tracepoints
5629 Static tracepoints are calls in the user program into a tracing
5630 library. One such library is a port of the LTTng kernel tracer to
5631 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
5632 When debugging with GDBserver, GDB now supports combining the GDB
5633 tracepoint machinery with such libraries. For example: the user can
5634 use GDB to probe a static tracepoint marker (a call from the user
5635 program into the tracing library) with the new "strace" command (see
5636 "New commands" below). This creates a "static tracepoint" in the
5637 breakpoint list, that can be manipulated with the same feature set
5638 as fast and regular tracepoints. E.g., collect registers, local and
5639 global variables, collect trace state variables, and define
5640 tracepoint conditions. In addition, the user can collect extra
5641 static tracepoint marker specific data, by collecting the new
5642 $_sdata internal variable. When analyzing the trace buffer, you can
5643 inspect $_sdata like any other variable available to GDB. For more
5644 information, see the "Tracepoints" chapter in GDB user manual. New
5645 remote packets have been defined to support static tracepoints, see
5646 the "New remote packets" section below.
5648 * Better reconstruction of tracepoints after disconnected tracing
5650 GDB will attempt to download the original source form of tracepoint
5651 definitions when starting a trace run, and then will upload these
5652 upon reconnection to the target, resulting in a more accurate
5653 reconstruction of the tracepoints that are in use on the target.
5657 You can now exercise direct control over the ways that GDB can
5658 affect your program. For instance, you can disallow the setting of
5659 breakpoints, so that the program can run continuously (assuming
5660 non-stop mode). In addition, the "observer" variable is available
5661 to switch all of the different controls; in observer mode, GDB
5662 cannot affect the target's behavior at all, which is useful for
5663 tasks like diagnosing live systems in the field.
5665 * The new convenience variable $_thread holds the number of the
5668 * New remote packets
5672 Return the address of the Windows Thread Information Block of a given thread.
5676 In response to several of the tracepoint packets, the target may now
5677 also respond with a number of intermediate `qRelocInsn' request
5678 packets before the final result packet, to have GDB handle
5679 relocating an instruction to execute at a different address. This
5680 is particularly useful for stubs that support fast tracepoints. GDB
5681 reports support for this feature in the qSupported packet.
5685 List static tracepoint markers in the target program.
5689 List static tracepoint markers at a given address in the target
5692 qXfer:statictrace:read
5694 Read the static trace data collected (by a `collect $_sdata'
5695 tracepoint action). The remote stub reports support for this packet
5696 to gdb's qSupported query.
5700 Send the current settings of GDB's permission flags.
5704 Send part of the source (textual) form of a tracepoint definition,
5705 which includes location, conditional, and action list.
5707 * The source command now accepts a -s option to force searching for the
5708 script in the source search path even if the script name specifies
5711 * New features in the GDB remote stub, GDBserver
5713 - GDBserver now support tracepoints (including fast tracepoints, and
5714 static tracepoints). The feature is currently supported by the
5715 i386-linux and amd64-linux builds. See the "Tracepoints support
5716 in gdbserver" section in the manual for more information.
5718 GDBserver JIT compiles the tracepoint's conditional agent
5719 expression bytecode into native code whenever possible for low
5720 overhead dynamic tracepoints conditionals. For such tracepoints,
5721 an expression that examines program state is evaluated when the
5722 tracepoint is reached, in order to determine whether to capture
5723 trace data. If the condition is simple and false, processing the
5724 tracepoint finishes very quickly and no data is gathered.
5726 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
5727 for static tracepoints support.
5729 - GDBserver now supports x86_64 Windows 64-bit debugging.
5731 * GDB now sends xmlRegisters= in qSupported packet to indicate that
5732 it understands register description.
5734 * The --batch flag now disables pagination and queries.
5736 * X86 general purpose registers
5738 GDB now supports reading/writing byte, word and double-word x86
5739 general purpose registers directly. This means you can use, say,
5740 $ah or $ax to refer, respectively, to the byte register AH and
5741 16-bit word register AX that are actually portions of the 32-bit
5742 register EAX or 64-bit register RAX.
5744 * The `commands' command now accepts a range of breakpoints to modify.
5745 A plain `commands' following a command that creates multiple
5746 breakpoints affects all the breakpoints set by that command. This
5747 applies to breakpoints set by `rbreak', and also applies when a
5748 single `break' command creates multiple breakpoints (e.g.,
5749 breakpoints on overloaded c++ functions).
5751 * The `rbreak' command now accepts a filename specification as part of
5752 its argument, limiting the functions selected by the regex to those
5753 in the specified file.
5755 * Support for remote debugging Windows and SymbianOS shared libraries
5756 from Unix hosts has been improved. Non Windows GDB builds now can
5757 understand target reported file names that follow MS-DOS based file
5758 system semantics, such as file names that include drive letters and
5759 use the backslash character as directory separator. This makes it
5760 possible to transparently use the "set sysroot" and "set
5761 solib-search-path" on Unix hosts to point as host copies of the
5762 target's shared libraries. See the new command "set
5763 target-file-system-kind" described below, and the "Commands to
5764 specify files" section in the user manual for more information.
5768 eval template, expressions...
5769 Convert the values of one or more expressions under the control
5770 of the string template to a command line, and call it.
5772 set target-file-system-kind unix|dos-based|auto
5773 show target-file-system-kind
5774 Set or show the assumed file system kind for target reported file
5777 save breakpoints <filename>
5778 Save all current breakpoint definitions to a file suitable for use
5779 in a later debugging session. To read the saved breakpoint
5780 definitions, use the `source' command.
5782 `save tracepoints' is a new alias for `save-tracepoints'. The latter
5785 info static-tracepoint-markers
5786 Display information about static tracepoint markers in the target.
5788 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5789 Define a static tracepoint by probing a marker at the given
5790 function, line, address, or marker ID.
5794 Enable and disable observer mode.
5796 set may-write-registers on|off
5797 set may-write-memory on|off
5798 set may-insert-breakpoints on|off
5799 set may-insert-tracepoints on|off
5800 set may-insert-fast-tracepoints on|off
5801 set may-interrupt on|off
5802 Set individual permissions for GDB effects on the target. Note that
5803 some of these settings can have undesirable or surprising
5804 consequences, particularly when changed in the middle of a session.
5805 For instance, disabling the writing of memory can prevent
5806 breakpoints from being inserted, cause single-stepping to fail, or
5807 even crash your program, if you disable after breakpoints have been
5808 inserted. However, GDB should not crash.
5810 set record memory-query on|off
5811 show record memory-query
5812 Control whether to stop the inferior if memory changes caused
5813 by an instruction cannot be recorded.
5818 The disassemble command now supports "start,+length" form of two arguments.
5822 ** GDB now provides a new directory location, called the python directory,
5823 where Python scripts written for GDB can be installed. The location
5824 of that directory is <data-directory>/python, where <data-directory>
5825 is the GDB data directory. For more details, see section `Scripting
5826 GDB using Python' in the manual.
5828 ** The GDB Python API now has access to breakpoints, symbols, symbol
5829 tables, program spaces, inferiors, threads and frame's code blocks.
5830 Additionally, GDB Parameters can now be created from the API, and
5831 manipulated via set/show in the CLI.
5833 ** New functions gdb.target_charset, gdb.target_wide_charset,
5834 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5836 ** New exception gdb.GdbError.
5838 ** Pretty-printers are now also looked up in the current program space.
5840 ** Pretty-printers can now be individually enabled and disabled.
5842 ** GDB now looks for names of Python scripts to auto-load in a
5843 special section named `.debug_gdb_scripts', in addition to looking
5844 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5846 * Tracepoint actions were unified with breakpoint commands. In particular,
5847 there are no longer differences in "info break" output for breakpoints and
5848 tracepoints and the "commands" command can be used for both tracepoints and
5849 regular breakpoints.
5853 ARM Symbian arm*-*-symbianelf*
5855 * D language support.
5856 GDB now supports debugging programs written in the D programming
5859 * GDB now supports the extended ptrace interface for PowerPC which is
5860 available since Linux kernel version 2.6.34. This automatically enables
5861 any hardware breakpoints and additional hardware watchpoints available in
5862 the processor. The old ptrace interface exposes just one hardware
5863 watchpoint and no hardware breakpoints.
5865 * GDB is now able to use the Data Value Compare (DVC) register available on
5866 embedded PowerPC processors to implement in hardware simple watchpoint
5867 conditions of the form:
5869 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5871 This works in native GDB running on Linux kernels with the extended ptrace
5872 interface mentioned above.
5874 *** Changes in GDB 7.1
5878 ** Namespace Support
5880 GDB now supports importing of namespaces in C++. This enables the
5881 user to inspect variables from imported namespaces. Support for
5882 namespace aliasing has also been added. So, if a namespace is
5883 aliased in the current scope (e.g. namespace C=A; ) the user can
5884 print variables using the alias (e.g. (gdb) print C::x).
5888 All known bugs relating to the printing of virtual base class were
5889 fixed. It is now possible to call overloaded static methods using a
5894 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5895 and reinterpret_cast<> are now handled by the C++ expression parser.
5899 Xilinx MicroBlaze microblaze-*-*
5904 Xilinx MicroBlaze microblaze
5907 * Multi-program debugging.
5909 GDB now has support for multi-program (a.k.a. multi-executable or
5910 multi-exec) debugging. This allows for debugging multiple inferiors
5911 simultaneously each running a different program under the same GDB
5912 session. See "Debugging Multiple Inferiors and Programs" in the
5913 manual for more information. This implied some user visible changes
5914 in the multi-inferior support. For example, "info inferiors" now
5915 lists inferiors that are not running yet or that have exited
5916 already. See also "New commands" and "New options" below.
5918 * New tracing features
5920 GDB's tracepoint facility now includes several new features:
5922 ** Trace state variables
5924 GDB tracepoints now include support for trace state variables, which
5925 are variables managed by the target agent during a tracing
5926 experiment. They are useful for tracepoints that trigger each
5927 other, so for instance one tracepoint can count hits in a variable,
5928 and then a second tracepoint has a condition that is true when the
5929 count reaches a particular value. Trace state variables share the
5930 $-syntax of GDB convenience variables, and can appear in both
5931 tracepoint actions and condition expressions. Use the "tvariable"
5932 command to create, and "info tvariables" to view; see "Trace State
5933 Variables" in the manual for more detail.
5937 GDB now includes an option for defining fast tracepoints, which
5938 targets may implement more efficiently, such as by installing a jump
5939 into the target agent rather than a trap instruction. The resulting
5940 speedup can be by two orders of magnitude or more, although the
5941 tradeoff is that some program locations on some target architectures
5942 might not allow fast tracepoint installation, for instance if the
5943 instruction to be replaced is shorter than the jump. To request a
5944 fast tracepoint, use the "ftrace" command, with syntax identical to
5945 the regular trace command.
5947 ** Disconnected tracing
5949 It is now possible to detach GDB from the target while it is running
5950 a trace experiment, then reconnect later to see how the experiment
5951 is going. In addition, a new variable disconnected-tracing lets you
5952 tell the target agent whether to continue running a trace if the
5953 connection is lost unexpectedly.
5957 GDB now has the ability to save the trace buffer into a file, and
5958 then use that file as a target, similarly to you can do with
5959 corefiles. You can select trace frames, print data that was
5960 collected in them, and use tstatus to display the state of the
5961 tracing run at the moment that it was saved. To create a trace
5962 file, use "tsave <filename>", and to use it, do "target tfile
5965 ** Circular trace buffer
5967 You can ask the target agent to handle the trace buffer as a
5968 circular buffer, discarding the oldest trace frames to make room for
5969 newer ones, by setting circular-trace-buffer to on. This feature may
5970 not be available for all target agents.
5975 The disassemble command, when invoked with two arguments, now requires
5976 the arguments to be comma-separated.
5979 The info variables command now displays variable definitions. Files
5980 which only declare a variable are not shown.
5983 The source command is now capable of sourcing Python scripts.
5984 This feature is dependent on the debugger being build with Python
5987 Related to this enhancement is also the introduction of a new command
5988 "set script-extension" (see below).
5990 * New commands (for set/show, see "New options" below)
5992 record save [<FILENAME>]
5993 Save a file (in core file format) containing the process record
5994 execution log for replay debugging at a later time.
5996 record restore <FILENAME>
5997 Restore the process record execution log that was saved at an
5998 earlier time, for replay debugging.
6000 add-inferior [-copies <N>] [-exec <FILENAME>]
6003 clone-inferior [-copies <N>] [ID]
6004 Make a new inferior ready to execute the same program another
6005 inferior has loaded.
6010 maint info program-spaces
6011 List the program spaces loaded into GDB.
6013 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
6014 show remote interrupt-sequence
6015 Allow the user to select one of ^C, a BREAK signal or BREAK-g
6016 as the sequence to the remote target in order to interrupt the execution.
6017 Ctrl-C is a default. Some system prefers BREAK which is high level of
6018 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
6019 Magic SysRq g. It is BREAK signal and character 'g'.
6021 set remote interrupt-on-connect [on | off]
6022 show remote interrupt-on-connect
6023 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
6024 remote target when gdb connects to it. This is needed when you debug
6027 set remotebreak [on | off]
6029 Deprecated. Use "set/show remote interrupt-sequence" instead.
6031 tvariable $NAME [ = EXP ]
6032 Create or modify a trace state variable.
6035 List trace state variables and their values.
6037 delete tvariable $NAME ...
6038 Delete one or more trace state variables.
6041 Evaluate the given expressions without collecting anything into the
6042 trace buffer. (Valid in tracepoint actions only.)
6044 ftrace FN / FILE:LINE / *ADDR
6045 Define a fast tracepoint at the given function, line, or address.
6047 * New expression syntax
6049 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
6050 GDB now parses 0b101010 identically with 42.
6054 set follow-exec-mode new|same
6055 show follow-exec-mode
6056 Control whether GDB reuses the same inferior across an exec call or
6057 creates a new one. This is useful to be able to restart the old
6058 executable after the inferior having done an exec call.
6060 set default-collect EXPR, ...
6061 show default-collect
6062 Define a list of expressions to be collected at each tracepoint.
6063 This is a useful way to ensure essential items are not overlooked,
6064 such as registers or a critical global variable.
6066 set disconnected-tracing
6067 show disconnected-tracing
6068 If set to 1, the target is instructed to continue tracing if it
6069 loses its connection to GDB. If 0, the target is to stop tracing
6072 set circular-trace-buffer
6073 show circular-trace-buffer
6074 If set to on, the target is instructed to use a circular trace buffer
6075 and discard the oldest trace frames instead of stopping the trace due
6076 to a full trace buffer. If set to off, the trace stops when the buffer
6077 fills up. Some targets may not support this.
6079 set script-extension off|soft|strict
6080 show script-extension
6081 If set to "off", the debugger does not perform any script language
6082 recognition, and all sourced files are assumed to be GDB scripts.
6083 If set to "soft" (the default), files are sourced according to
6084 filename extension, falling back to GDB scripts if the first
6086 If set to "strict", files are sourced according to filename extension.
6088 set ada trust-PAD-over-XVS on|off
6089 show ada trust-PAD-over-XVS
6090 If off, activate a workaround against a bug in the debugging information
6091 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
6092 the GCC sources for more information about the GNAT encoding and
6093 PAD types in particular). It is always safe to set this option to
6094 off, but this introduces a slight performance penalty. The default
6097 * Python API Improvements
6099 ** GDB provides the new class gdb.LazyString. This is useful in
6100 some pretty-printing cases. The new method gdb.Value.lazy_string
6101 provides a simple way to create objects of this type.
6103 ** The fields returned by gdb.Type.fields now have an
6104 `is_base_class' attribute.
6106 ** The new method gdb.Type.range returns the range of an array type.
6108 ** The new method gdb.parse_and_eval can be used to parse and
6109 evaluate an expression.
6111 * New remote packets
6114 Define a trace state variable.
6117 Get the current value of a trace state variable.
6120 Set desired tracing behavior upon disconnection.
6123 Set the trace buffer to be linear or circular.
6126 Get data about the tracepoints currently in use.
6130 Process record now works correctly with hardware watchpoints.
6132 Multiple bug fixes have been made to the mips-irix port, making it
6133 much more reliable. In particular:
6134 - Debugging threaded applications is now possible again. Previously,
6135 GDB would hang while starting the program, or while waiting for
6136 the program to stop at a breakpoint.
6137 - Attaching to a running process no longer hangs.
6138 - An error occurring while loading a core file has been fixed.
6139 - Changing the value of the PC register now works again. This fixes
6140 problems observed when using the "jump" command, or when calling
6141 a function from GDB, or even when assigning a new value to $pc.
6142 - With the "finish" and "return" commands, the return value for functions
6143 returning a small array is now correctly printed.
6144 - It is now possible to break on shared library code which gets executed
6145 during a shared library init phase (code executed while executing
6146 their .init section). Previously, the breakpoint would have no effect.
6147 - GDB is now able to backtrace through the signal handler for
6148 non-threaded programs.
6150 PIE (Position Independent Executable) programs debugging is now supported.
6151 This includes debugging execution of PIC (Position Independent Code) shared
6152 libraries although for that, it should be possible to run such libraries as an
6155 *** Changes in GDB 7.0
6157 * GDB now has an interface for JIT compilation. Applications that
6158 dynamically generate code can create symbol files in memory and register
6159 them with GDB. For users, the feature should work transparently, and
6160 for JIT developers, the interface is documented in the GDB manual in the
6161 "JIT Compilation Interface" chapter.
6163 * Tracepoints may now be conditional. The syntax is as for
6164 breakpoints; either an "if" clause appended to the "trace" command,
6165 or the "condition" command is available. GDB sends the condition to
6166 the target for evaluation using the same bytecode format as is used
6167 for tracepoint actions.
6169 * The disassemble command now supports: an optional /r modifier, print the
6170 raw instructions in hex as well as in symbolic form, and an optional /m
6171 modifier to print mixed source+assembly.
6173 * Process record and replay
6175 In a architecture environment that supports ``process record and
6176 replay'', ``process record and replay'' target can record a log of
6177 the process execution, and replay it with both forward and reverse
6180 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
6181 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
6182 set execution-direction {forward|reverse}, for targets that support
6185 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
6186 feature is available with a native GDB running on kernel version
6189 * GDB now has support for multi-byte and wide character sets on the
6190 target. Strings whose character type is wchar_t, char16_t, or
6191 char32_t are now correctly printed. GDB supports wide- and unicode-
6192 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
6193 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
6194 `printf'. This feature requires iconv to work properly; if your
6195 system does not have a working iconv, GDB can use GNU libiconv. See
6196 the installation instructions for more information.
6198 * GDB now supports automatic retrieval of shared library files from
6199 remote targets. To use this feature, specify a system root that begins
6200 with the `remote:' prefix, either via the `set sysroot' command or via
6201 the `--with-sysroot' configure-time option.
6203 * "info sharedlibrary" now takes an optional regex of libraries to show,
6204 and it now reports if a shared library has no debugging information.
6206 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
6207 now complete on file names.
6209 * When completing in expressions, gdb will attempt to limit
6210 completions to allowable structure or union fields, where appropriate.
6211 For instance, consider:
6213 # struct example { int f1; double f2; };
6214 # struct example variable;
6217 If the user types TAB at the end of this command line, the available
6218 completions will be "f1" and "f2".
6220 * Inlined functions are now supported. They show up in backtraces, and
6221 the "step", "next", and "finish" commands handle them automatically.
6223 * GDB now supports the token-splicing (##) and stringification (#)
6224 operators when expanding macros. It also supports variable-arity
6227 * GDB now supports inspecting extra signal information, exported by
6228 the new $_siginfo convenience variable. The feature is currently
6229 implemented on linux ARM, i386 and amd64.
6231 * GDB can now display the VFP floating point registers and NEON vector
6232 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
6233 can provide these registers (requires Linux 2.6.30 or later). Remote
6234 and simulator targets may also provide them.
6236 * New remote packets
6239 Search memory for a sequence of bytes.
6242 Turn off `+'/`-' protocol acknowledgments to permit more efficient
6243 operation over reliable transport links. Use of this packet is
6244 controlled by the `set remote noack-packet' command.
6247 Kill the process with the specified process ID. Use this in preference
6248 to `k' when multiprocess protocol extensions are supported.
6251 Obtains additional operating system information
6255 Read or write additional signal information.
6257 * Removed remote protocol undocumented extension
6259 An undocumented extension to the remote protocol's `S' stop reply
6260 packet that permitted the stub to pass a process id was removed.
6261 Remote servers should use the `T' stop reply packet instead.
6263 * GDB now supports multiple function calling conventions according to the
6264 DWARF-2 DW_AT_calling_convention function attribute.
6266 * The SH target utilizes the aforementioned change to distinguish between gcc
6267 and Renesas calling convention. It also adds the new CLI commands
6268 `set/show sh calling-convention'.
6270 * GDB can now read compressed debug sections, as produced by GNU gold
6271 with the --compress-debug-sections=zlib flag.
6273 * 64-bit core files are now supported on AIX.
6275 * Thread switching is now supported on Tru64.
6277 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
6278 which will be allocated using malloc later in program execution.
6280 * The qXfer:libraries:read remote protocol packet now allows passing a
6281 list of section offsets.
6283 * On GNU/Linux, GDB can now attach to stopped processes. Several race
6284 conditions handling signals delivered during attach or thread creation
6285 have also been fixed.
6287 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
6288 From the user's standpoint, all unqualified instances of True and False
6289 are treated as the standard definitions, regardless of context.
6291 * GDB now parses C++ symbol and type names more flexibly. For
6294 template<typename T> class C { };
6297 GDB will now correctly handle all of:
6299 ptype C<char const *>
6300 ptype C<char const*>
6301 ptype C<const char *>
6302 ptype C<const char*>
6304 * New features in the GDB remote stub, gdbserver
6306 - The "--wrapper" command-line argument tells gdbserver to use a
6307 wrapper program to launch programs for debugging.
6309 - On PowerPC and S/390 targets, it is now possible to use a single
6310 gdbserver executable to debug both 32-bit and 64-bit programs.
6311 (This requires gdbserver itself to be built as a 64-bit executable.)
6313 - gdbserver uses the new noack protocol mode for TCP connections to
6314 reduce communications latency, if also supported and enabled in GDB.
6316 - Support for the sparc64-linux-gnu target is now included in
6319 - The amd64-linux build of gdbserver now supports debugging both
6320 32-bit and 64-bit programs.
6322 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
6323 now support hardware watchpoints, and will use them automatically
6328 GDB now has support for scripting using Python. Whether this is
6329 available is determined at configure time.
6331 New GDB commands can now be written in Python.
6333 * Ada tasking support
6335 Ada tasks can now be inspected in GDB. The following commands have
6339 Print the list of Ada tasks.
6341 Print detailed information about task number N.
6343 Print the task number of the current task.
6345 Switch the context of debugging to task number N.
6347 * Support for user-defined prefixed commands. The "define" command can
6348 add new commands to existing prefixes, e.g. "target".
6350 * Multi-inferior, multi-process debugging.
6352 GDB now has generalized support for multi-inferior debugging. See
6353 "Debugging Multiple Inferiors" in the manual for more information.
6354 Although availability still depends on target support, the command
6355 set is more uniform now. The GNU/Linux specific multi-forks support
6356 has been migrated to this new framework. This implied some user
6357 visible changes; see "New commands" and also "Removed commands"
6360 * Target descriptions can now describe the target OS ABI. See the
6361 "Target Description Format" section in the user manual for more
6364 * Target descriptions can now describe "compatible" architectures
6365 to indicate that the target can execute applications for a different
6366 architecture in addition to those for the main target architecture.
6367 See the "Target Description Format" section in the user manual for
6370 * Multi-architecture debugging.
6372 GDB now includes general supports for debugging applications on
6373 hybrid systems that use more than one single processor architecture
6374 at the same time. Each such hybrid architecture still requires
6375 specific support to be added. The only hybrid architecture supported
6376 in this version of GDB is the Cell Broadband Engine.
6378 * GDB now supports integrated debugging of Cell/B.E. applications that
6379 use both the PPU and SPU architectures. To enable support for hybrid
6380 Cell/B.E. debugging, you need to configure GDB to support both the
6381 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
6382 --enable-targets configure option.
6384 * Non-stop mode debugging.
6386 For some targets, GDB now supports an optional mode of operation in
6387 which you can examine stopped threads while other threads continue
6388 to execute freely. This is referred to as non-stop mode, with the
6389 old mode referred to as all-stop mode. See the "Non-Stop Mode"
6390 section in the user manual for more information.
6392 To be able to support remote non-stop debugging, a remote stub needs
6393 to implement the non-stop mode remote protocol extensions, as
6394 described in the "Remote Non-Stop" section of the user manual. The
6395 GDB remote stub, gdbserver, has been adjusted to support these
6396 extensions on linux targets.
6398 * New commands (for set/show, see "New options" below)
6400 catch syscall [NAME(S) | NUMBER(S)]
6401 Catch system calls. Arguments, which should be names of system
6402 calls or their numbers, mean catch only those syscalls. Without
6403 arguments, every syscall will be caught. When the inferior issues
6404 any of the specified syscalls, GDB will stop and announce the system
6405 call, both when it is called and when its call returns. This
6406 feature is currently available with a native GDB running on the
6407 Linux Kernel, under the following architectures: x86, x86_64,
6408 PowerPC and PowerPC64.
6410 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
6412 Search memory for a sequence of bytes.
6414 maint set python print-stack
6415 maint show python print-stack
6416 Show a stack trace when an error is encountered in a Python script.
6419 Invoke CODE by passing it to the Python interpreter.
6424 These allow macros to be defined, undefined, and listed
6428 Show operating system information about processes.
6431 List the inferiors currently under GDB's control.
6434 Switch focus to inferior number NUM.
6437 Detach from inferior number NUM.
6440 Kill inferior number NUM.
6444 set spu stop-on-load
6445 show spu stop-on-load
6446 Control whether to stop for new SPE threads during Cell/B.E. debugging.
6448 set spu auto-flush-cache
6449 show spu auto-flush-cache
6450 Control whether to automatically flush the software-managed cache
6451 during Cell/B.E. debugging.
6453 set sh calling-convention
6454 show sh calling-convention
6455 Control the calling convention used when calling SH target functions.
6458 show debug timestamp
6459 Control display of timestamps with GDB debugging output.
6461 set disassemble-next-line
6462 show disassemble-next-line
6463 Control display of disassembled source lines or instructions when
6466 set remote noack-packet
6467 show remote noack-packet
6468 Set/show the use of remote protocol QStartNoAckMode packet. See above
6469 under "New remote packets."
6471 set remote query-attached-packet
6472 show remote query-attached-packet
6473 Control use of remote protocol `qAttached' (query-attached) packet.
6475 set remote read-siginfo-object
6476 show remote read-siginfo-object
6477 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
6480 set remote write-siginfo-object
6481 show remote write-siginfo-object
6482 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
6485 set remote reverse-continue
6486 show remote reverse-continue
6487 Control use of remote protocol 'bc' (reverse-continue) packet.
6489 set remote reverse-step
6490 show remote reverse-step
6491 Control use of remote protocol 'bs' (reverse-step) packet.
6493 set displaced-stepping
6494 show displaced-stepping
6495 Control displaced stepping mode. Displaced stepping is a way to
6496 single-step over breakpoints without removing them from the debuggee.
6497 Also known as "out-of-line single-stepping".
6500 show debug displaced
6501 Control display of debugging info for displaced stepping.
6503 maint set internal-error
6504 maint show internal-error
6505 Control what GDB does when an internal error is detected.
6507 maint set internal-warning
6508 maint show internal-warning
6509 Control what GDB does when an internal warning is detected.
6514 Use a wrapper program to launch programs for debugging.
6516 set multiple-symbols (all|ask|cancel)
6517 show multiple-symbols
6518 The value of this variable can be changed to adjust the debugger behavior
6519 when an expression or a breakpoint location contains an ambiguous symbol
6520 name (an overloaded function name, for instance).
6522 set breakpoint always-inserted
6523 show breakpoint always-inserted
6524 Keep breakpoints always inserted in the target, as opposed to inserting
6525 them when resuming the target, and removing them when the target stops.
6526 This option can improve debugger performance on slow remote targets.
6528 set arm fallback-mode (arm|thumb|auto)
6529 show arm fallback-mode
6530 set arm force-mode (arm|thumb|auto)
6532 These commands control how ARM GDB determines whether instructions
6533 are ARM or Thumb. The default for both settings is auto, which uses
6534 the current CPSR value for instructions without symbols; previous
6535 versions of GDB behaved as if "set arm fallback-mode arm".
6537 set arm unwind-secure-frames
6538 Enable unwinding from Non-secure to Secure mode on Cortex-M with
6540 This can trigger security exceptions when unwinding exception stacks.
6542 set disable-randomization
6543 show disable-randomization
6544 Standalone programs run with the virtual address space randomization enabled
6545 by default on some platforms. This option keeps the addresses stable across
6546 multiple debugging sessions.
6550 Control whether other threads are stopped or not when some thread hits
6555 Requests that asynchronous execution is enabled in the target, if available.
6556 In this case, it's possible to resume target in the background, and interact
6557 with GDB while the target is running. "show target-async" displays the
6558 current state of asynchronous execution of the target.
6560 set target-wide-charset
6561 show target-wide-charset
6562 The target-wide-charset is the name of the character set that GDB
6563 uses when printing characters whose type is wchar_t.
6565 set tcp auto-retry (on|off)
6567 set tcp connect-timeout
6568 show tcp connect-timeout
6569 These commands allow GDB to retry failed TCP connections to a remote stub
6570 with a specified timeout period; this is useful if the stub is launched
6571 in parallel with GDB but may not be ready to accept connections immediately.
6573 set libthread-db-search-path
6574 show libthread-db-search-path
6575 Control list of directories which GDB will search for appropriate
6578 set schedule-multiple (on|off)
6579 show schedule-multiple
6580 Allow GDB to resume all threads of all processes or only threads of
6581 the current process.
6585 Use more aggressive caching for accesses to the stack. This improves
6586 performance of remote debugging (particularly backtraces) without
6587 affecting correctness.
6589 set interactive-mode (on|off|auto)
6590 show interactive-mode
6591 Control whether GDB runs in interactive mode (on) or not (off).
6592 When in interactive mode, GDB waits for the user to answer all
6593 queries. Otherwise, GDB does not wait and assumes the default
6594 answer. When set to auto (the default), GDB determines which
6595 mode to use based on the stdin settings.
6600 For program forks, this is replaced by the new more generic `info
6601 inferiors' command. To list checkpoints, you can still use the
6602 `info checkpoints' command, which was an alias for the `info forks'
6606 Replaced by the new `inferior' command. To switch between
6607 checkpoints, you can still use the `restart' command, which was an
6608 alias for the `fork' command.
6611 This is removed, since some targets don't have a notion of
6612 processes. To switch between processes, you can still use the
6613 `inferior' command using GDB's own inferior number.
6616 For program forks, this is replaced by the new more generic `kill
6617 inferior' command. To delete a checkpoint, you can still use the
6618 `delete checkpoint' command, which was an alias for the `delete
6622 For program forks, this is replaced by the new more generic `detach
6623 inferior' command. To detach a checkpoint, you can still use the
6624 `detach checkpoint' command, which was an alias for the `detach
6627 * New native configurations
6629 x86/x86_64 Darwin i[34567]86-*-darwin*
6631 x86_64 MinGW x86_64-*-mingw*
6635 Lattice Mico32 lm32-*
6636 x86 DICOS i[34567]86-*-dicos*
6637 x86_64 DICOS x86_64-*-dicos*
6640 * The GDB remote stub, gdbserver, now supports x86 Windows CE
6641 (mingw32ce) debugging.
6647 These commands were actually not implemented on any target.
6649 *** Changes in GDB 6.8
6651 * New native configurations
6653 NetBSD/hppa hppa*-*netbsd*
6654 Xtensa GNU/Linux xtensa*-*-linux*
6658 NetBSD/hppa hppa*-*-netbsd*
6659 Xtensa GNU/Linux xtensa*-*-linux*
6661 * Change in command line behavior -- corefiles vs. process ids.
6663 When the '-p NUMBER' or '--pid NUMBER' options are used, and
6664 attaching to process NUMBER fails, GDB no longer attempts to open a
6665 core file named NUMBER. Attaching to a program using the -c option
6666 is no longer supported. Instead, use the '-p' or '--pid' options.
6668 * GDB can now be built as a native debugger for debugging Windows x86
6669 (mingw32) Portable Executable (PE) programs.
6671 * Pending breakpoints no longer change their number when their address
6674 * GDB now supports breakpoints with multiple locations,
6675 including breakpoints on C++ constructors, inside C++ templates,
6676 and in inlined functions.
6678 * GDB's ability to debug optimized code has been improved. GDB more
6679 accurately identifies function bodies and lexical blocks that occupy
6680 more than one contiguous range of addresses.
6682 * Target descriptions can now describe registers for PowerPC.
6684 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
6685 registers on PowerPC targets.
6687 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
6688 targets even when the libthread_db library is not available.
6690 * The GDB remote stub, gdbserver, now supports the new file transfer
6691 commands (remote put, remote get, and remote delete).
6693 * The GDB remote stub, gdbserver, now supports run and attach in
6694 extended-remote mode.
6696 * hppa*64*-*-hpux11* target broken
6697 The debugger is unable to start a program and fails with the following
6698 error: "Error trying to get information about dynamic linker".
6699 The gdb-6.7 release is also affected.
6701 * GDB now supports the --enable-targets= configure option to allow
6702 building a single GDB executable that supports multiple remote
6703 target architectures.
6705 * GDB now supports debugging C and C++ programs which use the
6706 Decimal Floating Point extension. In addition, the PowerPC target
6707 now has a set of pseudo-registers to inspect decimal float values
6708 stored in two consecutive float registers.
6710 * The -break-insert MI command can optionally create pending
6713 * Improved support for debugging Ada
6714 Many improvements to the Ada language support have been made. These
6716 - Better support for Ada2005 interface types
6717 - Improved handling of arrays and slices in general
6718 - Better support for Taft-amendment types
6719 - The '{type} ADDRESS' expression is now allowed on the left hand-side
6721 - Improved command completion in Ada
6724 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
6729 set print frame-arguments (all|scalars|none)
6730 show print frame-arguments
6731 The value of this variable can be changed to control which argument
6732 values should be printed by the debugger when displaying a frame.
6737 Transfer files to and from a remote target, and delete remote files.
6744 Transfer files to and from a remote target, and delete remote files.
6746 * New remote packets
6753 Open, close, read, write, and delete files on the remote system.
6756 Attach to an existing process on the remote system, in extended-remote
6760 Run a new process on the remote system, in extended-remote mode.
6762 *** Changes in GDB 6.7
6764 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
6765 bfd, libiberty and opcodes, as revealed by static analysis donated by
6766 Coverity, Inc. (http://scan.coverity.com).
6768 * When looking up multiply-defined global symbols, GDB will now prefer the
6769 symbol definition in the current shared library if it was built using the
6770 -Bsymbolic linker option.
6772 * When the Text User Interface (TUI) is not configured, GDB will now
6773 recognize the -tui command-line option and print a message that the TUI
6776 * The GDB remote stub, gdbserver, now has lower overhead for high
6777 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
6779 * GDB for MIPS targets now autodetects whether a remote target provides
6780 32-bit or 64-bit register values.
6782 * Support for C++ member pointers has been improved.
6784 * GDB now understands XML target descriptions, which specify the
6785 target's overall architecture. GDB can read a description from
6786 a local file or over the remote serial protocol.
6788 * Vectors of single-byte data use a new integer type which is not
6789 automatically displayed as character or string data.
6791 * The /s format now works with the print command. It displays
6792 arrays of single-byte integers and pointers to single-byte integers
6795 * Target descriptions can now describe target-specific registers,
6796 for architectures which have implemented the support (currently
6797 only ARM, M68K, and MIPS).
6799 * GDB and the GDB remote stub, gdbserver, now support the XScale
6802 * The GDB remote stub, gdbserver, has been updated to support
6803 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6804 has been rewritten to use the standard GDB remote protocol.
6806 * GDB can now step into C++ functions which are called through thunks.
6808 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6810 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6811 layout. It also supports a TextSeg= and DataSeg= response when only
6812 segment base addresses (rather than offsets) are available.
6814 * The /i format now outputs any trailing branch delay slot instructions
6815 immediately following the last instruction within the count specified.
6817 * The GDB remote protocol "T" stop reply packet now supports a
6818 "library" response. Combined with the new "qXfer:libraries:read"
6819 packet, this response allows GDB to debug shared libraries on targets
6820 where the operating system manages the list of loaded libraries (e.g.
6821 Windows and SymbianOS).
6823 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6824 (DLLs) on Windows and Windows CE targets.
6826 * GDB now supports a faster verification that a .debug file matches its binary
6827 according to its build-id signature, if the signature is present.
6833 Enable or disable hardware flow control (RTS/CTS) on the serial port
6834 when debugging using remote targets.
6836 set mem inaccessible-by-default
6837 show mem inaccessible-by-default
6838 If the target supplies a memory map, for instance via the remote
6839 protocol's "qXfer:memory-map:read" packet, setting this variable
6840 prevents GDB from accessing memory outside the memory map. This
6841 is useful for targets with memory mapped registers or which react
6842 badly to accesses of unmapped address space.
6844 set breakpoint auto-hw
6845 show breakpoint auto-hw
6846 If the target supplies a memory map, for instance via the remote
6847 protocol's "qXfer:memory-map:read" packet, setting this variable
6848 lets GDB use hardware breakpoints automatically for memory regions
6849 where it can not use software breakpoints. This covers both the
6850 "break" command and internal breakpoints used for other commands
6851 including "next" and "finish".
6854 catch exception unhandled
6855 Stop the program execution when Ada exceptions are raised.
6858 Stop the program execution when an Ada assertion failed.
6862 Set an alternate system root for target files. This is a more
6863 general version of "set solib-absolute-prefix", which is now
6864 an alias to "set sysroot".
6867 Provide extended SPU facility status information. This set of
6868 commands is available only when debugging the Cell/B.E. SPU
6871 * New native configurations
6873 OpenBSD/sh sh*-*openbsd*
6876 unset tdesc filename
6878 Use the specified local file as an XML target description, and do
6879 not query the target for its built-in description.
6883 OpenBSD/sh sh*-*-openbsd*
6884 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
6885 Toshiba Media Processor mep-elf
6887 * New remote packets
6890 Ignore the specified signals; pass them directly to the debugged program
6891 without stopping other threads or reporting them to GDB.
6893 qXfer:features:read:
6894 Read an XML target description from the target, which describes its
6899 Read or write contents of an spufs file on the target system. These
6900 packets are available only on the Cell/B.E. SPU architecture.
6902 qXfer:libraries:read:
6903 Report the loaded shared libraries. Combined with new "T" packet
6904 response, this packet allows GDB to debug shared libraries on
6905 targets where the operating system manages the list of loaded
6906 libraries (e.g. Windows and SymbianOS).
6910 Support for these obsolete configurations has been removed.
6918 i[34567]86-*-lynxos*
6919 i[34567]86-*-netware*
6920 i[34567]86-*-sco3.2v5*
6921 i[34567]86-*-sco3.2v4*
6923 i[34567]86-*-sysv4.2*
6926 i[34567]86-*-unixware2*
6927 i[34567]86-*-unixware*
6936 * Other removed features
6943 Various m68k-only ROM monitors.
6950 Various Renesas ROM monitors and debugging interfaces for SH and
6955 Support for a Macraigor serial interface to on-chip debugging.
6956 GDB does not directly support the newer parallel or USB
6961 A debug information format. The predecessor to DWARF 2 and
6962 DWARF 3, which are still supported.
6964 Support for the HP aCC compiler on HP-UX/PA-RISC
6966 SOM-encapsulated symbolic debugging information, automatic
6967 invocation of pxdb, and the aCC custom C++ ABI. This does not
6968 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6969 with aCC can still be debugged on an assembly level.
6971 MIPS ".pdr" sections
6973 A MIPS-specific format used to describe stack frame layout
6974 in debugging information.
6978 GDB could work with an older version of Guile to debug
6979 the interpreter and Scheme programs running in it.
6981 set mips stack-arg-size
6982 set mips saved-gpreg-size
6984 Use "set mips abi" to control parameter passing for MIPS.
6986 *** Changes in GDB 6.6
6991 Cell Broadband Engine SPU spu-elf
6993 * GDB can now be configured as a cross-debugger targeting native Windows
6994 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6995 running on a Windows system over TCP/IP to debug Windows programs.
6997 * The GDB remote stub, gdbserver, has been updated to support Windows and
6998 Cygwin debugging. Both single-threaded and multi-threaded programs are
7001 * The "set trust-readonly-sections" command works again. This command was
7002 broken in GDB 6.3, 6.4, and 6.5.
7004 * The "load" command now supports writing to flash memory, if the remote
7005 stub provides the required support.
7007 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
7008 longer requires symbolic debug information (e.g. DWARF-2).
7013 unset substitute-path
7014 show substitute-path
7015 Manage a list of substitution rules that GDB uses to rewrite the name
7016 of the directories where the sources are located. This can be useful
7017 for instance when the sources were moved to a different location
7018 between compilation and debugging.
7022 Print each CLI command as it is executed. Each command is prefixed with
7023 a number of `+' symbols representing the nesting depth.
7024 The source command now has a `-v' option to enable the same feature.
7028 The ARM Demon monitor support (RDP protocol, "target rdp").
7030 Kernel Object Display, an embedded debugging feature which only worked with
7031 an obsolete version of Cisco IOS.
7033 The 'set download-write-size' and 'show download-write-size' commands.
7035 * New remote packets
7038 Tell a stub about GDB client features, and request remote target features.
7039 The first feature implemented is PacketSize, which allows the target to
7040 specify the size of packets it can handle - to minimize the number of
7041 packets required and improve performance when connected to a remote
7045 Fetch an OS auxiliary vector from the remote stub. This packet is a
7046 more efficient replacement for qPart:auxv:read.
7048 qXfer:memory-map:read:
7049 Fetch a memory map from the remote stub, including information about
7050 RAM, ROM, and flash memory devices.
7055 Erase and program a flash memory device.
7057 * Removed remote packets
7060 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
7061 used it, and only gdbserver implemented it.
7063 *** Changes in GDB 6.5
7067 Renesas M32C/M16C m32c-elf
7069 Morpho Technologies ms1 ms1-elf
7073 init-if-undefined Initialize a convenience variable, but
7074 only if it doesn't already have a value.
7076 The following commands are presently only implemented for native GNU/Linux:
7078 checkpoint Save a snapshot of the program state.
7080 restart <n> Return the program state to a
7081 previously saved state.
7083 info checkpoints List currently saved checkpoints.
7085 delete-checkpoint <n> Delete a previously saved checkpoint.
7087 set|show detach-on-fork Tell gdb whether to detach from a newly
7088 forked process, or to keep debugging it.
7090 info forks List forks of the user program that
7091 are available to be debugged.
7093 fork <n> Switch to debugging one of several
7094 forks of the user program that are
7095 available to be debugged.
7097 delete-fork <n> Delete a fork from the list of forks
7098 that are available to be debugged (and
7099 kill the forked process).
7101 detach-fork <n> Delete a fork from the list of forks
7102 that are available to be debugged (and
7103 allow the process to continue).
7107 Morpho Technologies ms2 ms1-elf
7109 * Improved Windows host support
7111 GDB now builds as a cross debugger hosted on i686-mingw32, including
7112 native console support, and remote communications using either
7113 network sockets or serial ports.
7115 * Improved Modula-2 language support
7117 GDB can now print most types in the Modula-2 syntax. This includes:
7118 basic types, set types, record types, enumerated types, range types,
7119 pointer types and ARRAY types. Procedure var parameters are correctly
7120 printed and hexadecimal addresses and character constants are also
7121 written in the Modula-2 syntax. Best results can be obtained by using
7122 GNU Modula-2 together with the -gdwarf-2 command line option.
7126 The ARM rdi-share module.
7128 The Netware NLM debug server.
7130 *** Changes in GDB 6.4
7132 * New native configurations
7134 OpenBSD/arm arm*-*-openbsd*
7135 OpenBSD/mips64 mips64-*-openbsd*
7139 Morpho Technologies ms1 ms1-elf
7141 * New command line options
7143 --batch-silent As for --batch, but totally silent.
7144 --return-child-result The debugger will exist with the same value
7145 the child (debugged) program exited with.
7146 --eval-command COMMAND, -ex COMMAND
7147 Execute a single GDB CLI command. This may be
7148 specified multiple times and in conjunction
7149 with the --command (-x) option.
7151 * Deprecated commands removed
7153 The following commands, that were deprecated in 2000, have been
7157 set|show arm disassembly-flavor set|show arm disassembler
7158 othernames set arm disassembler
7159 set|show remotedebug set|show debug remote
7160 set|show archdebug set|show debug arch
7161 set|show eventdebug set|show debug event
7164 * New BSD user-level threads support
7166 It is now possible to debug programs using the user-level threads
7167 library on OpenBSD and FreeBSD. Currently supported (target)
7170 FreeBSD/amd64 x86_64-*-freebsd*
7171 FreeBSD/i386 i386-*-freebsd*
7172 OpenBSD/i386 i386-*-openbsd*
7174 Note that the new kernel threads libraries introduced in FreeBSD 5.x
7175 are not yet supported.
7177 * New support for Matsushita MN10300 w/sim added
7178 (Work in progress). mn10300-elf.
7180 * REMOVED configurations and files
7182 VxWorks and the XDR protocol *-*-vxworks
7183 Motorola MCORE mcore-*-*
7184 National Semiconductor NS32000 ns32k-*-*
7186 * New "set print array-indexes" command
7188 After turning this setting "on", GDB prints the index of each element
7189 when displaying arrays. The default is "off" to preserve the previous
7192 * VAX floating point support
7194 GDB now supports the not-quite-ieee VAX F and D floating point formats.
7196 * User-defined command support
7198 In addition to using $arg0..$arg9 for argument passing, it is now possible
7199 to use $argc to determine now many arguments have been passed. See the
7200 section on user-defined commands in the user manual for more information.
7202 *** Changes in GDB 6.3:
7204 * New command line option
7206 GDB now accepts -l followed by a number to set the timeout for remote
7209 * GDB works with GCC -feliminate-dwarf2-dups
7211 GDB now supports a more compact representation of DWARF-2 debug
7212 information using DW_FORM_ref_addr references. These are produced
7213 by GCC with the option -feliminate-dwarf2-dups and also by some
7214 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
7215 to use -feliminate-dwarf2-dups.
7217 * Internationalization
7219 When supported by the host system, GDB will be built with
7220 internationalization (libintl). The task of marking up the sources is
7221 continued, we're looking forward to our first translation.
7225 Initial support for debugging programs compiled with the GNAT
7226 implementation of the Ada programming language has been integrated
7227 into GDB. In this release, support is limited to expression evaluation.
7229 * New native configurations
7231 GNU/Linux/m32r m32r-*-linux-gnu
7235 GDB's remote protocol now includes support for the 'p' packet. This
7236 packet is used to fetch individual registers from a remote inferior.
7238 * END-OF-LIFE registers[] compatibility module
7240 GDB's internal register infrastructure has been completely rewritten.
7241 The new infrastructure making possible the implementation of key new
7242 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
7245 GDB 6.3 will be the last release to include the registers[]
7246 compatibility module that allowed out-of-date configurations to
7247 continue to work. This change directly impacts the following
7257 powerpc bdm protocol
7259 Unless there is activity to revive these configurations, they will be
7260 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
7262 * OBSOLETE configurations and files
7264 Configurations that have been declared obsolete in this release have
7265 been commented out. Unless there is activity to revive these
7266 configurations, the next release of GDB will have their sources
7267 permanently REMOVED.
7276 *** Changes in GDB 6.2.1:
7278 * MIPS `break main; run' gave an heuristic-fence-post warning
7280 When attempting to run even a simple program, a warning about
7281 heuristic-fence-post being hit would be reported. This problem has
7284 * MIPS IRIX 'long double' crashed GDB
7286 When examining a long double variable, GDB would get a segmentation
7287 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
7288 IRIX long double values).
7292 A bug in the VAX stack code was causing problems with the "next"
7293 command. This problem has been fixed.
7295 *** Changes in GDB 6.2:
7297 * Fix for ``many threads''
7299 On GNU/Linux systems that use the NPTL threads library, a program
7300 rapidly creating and deleting threads would confuse GDB leading to the
7303 ptrace: No such process.
7304 thread_db_get_info: cannot get thread info: generic error
7306 This problem has been fixed.
7308 * "-async" and "-noasync" options removed.
7310 Support for the broken "-noasync" option has been removed (it caused
7313 * New ``start'' command.
7315 This command runs the program until the beginning of the main procedure.
7317 * New BSD Kernel Data Access Library (libkvm) interface
7319 Using ``target kvm'' it is now possible to debug kernel core dumps and
7320 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
7321 platforms. Currently supported (native-only) configurations are:
7323 FreeBSD/amd64 x86_64-*-freebsd*
7324 FreeBSD/i386 i?86-*-freebsd*
7325 NetBSD/i386 i?86-*-netbsd*
7326 NetBSD/m68k m68*-*-netbsd*
7327 NetBSD/sparc sparc-*-netbsd*
7328 OpenBSD/amd64 x86_64-*-openbsd*
7329 OpenBSD/i386 i?86-*-openbsd*
7330 OpenBSD/m68k m68*-openbsd*
7331 OpenBSD/sparc sparc-*-openbsd*
7333 * Signal trampoline code overhauled
7335 Many generic problems with GDB's signal handling code have been fixed.
7336 These include: backtraces through non-contiguous stacks; recognition
7337 of sa_sigaction signal trampolines; backtrace from a NULL pointer
7338 call; backtrace through a signal trampoline; step into and out of
7339 signal handlers; and single-stepping in the signal trampoline.
7341 Please note that kernel bugs are a limiting factor here. These
7342 features have been shown to work on an s390 GNU/Linux system that
7343 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
7345 * Cygwin support for DWARF 2 added.
7347 * New native configurations
7349 GNU/Linux/hppa hppa*-*-linux*
7350 OpenBSD/hppa hppa*-*-openbsd*
7351 OpenBSD/m68k m68*-*-openbsd*
7352 OpenBSD/m88k m88*-*-openbsd*
7353 OpenBSD/powerpc powerpc-*-openbsd*
7354 NetBSD/vax vax-*-netbsd*
7355 OpenBSD/vax vax-*-openbsd*
7357 * END-OF-LIFE frame compatibility module
7359 GDB's internal frame infrastructure has been completely rewritten.
7360 The new infrastructure making it possible to support key new features
7361 including DWARF 2 Call Frame Information. To aid in the task of
7362 migrating old configurations to this new infrastructure, a
7363 compatibility module, that allowed old configurations to continue to
7364 work, was also included.
7366 GDB 6.2 will be the last release to include this frame compatibility
7367 module. This change directly impacts the following configurations:
7377 Unless there is activity to revive these configurations, they will be
7378 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
7380 * REMOVED configurations and files
7382 Sun 3, running SunOS 3 m68*-*-sunos3*
7383 Sun 3, running SunOS 4 m68*-*-sunos4*
7384 Sun 2, running SunOS 3 m68000-*-sunos3*
7385 Sun 2, running SunOS 4 m68000-*-sunos4*
7386 Motorola 680x0 running LynxOS m68*-*-lynxos*
7387 AT&T 3b1/Unix pc m68*-att-*
7388 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
7389 decstation mips-dec-* mips-little-*
7390 riscos mips-*-riscos* mips-*-sysv*
7391 sonymips mips-sony-*
7392 sysv mips*-*-sysv4* (IRIX 5/6 not included)
7394 *** Changes in GDB 6.1.1:
7396 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
7398 The TUI (Text-mode User Interface) is now built as part of a default
7399 GDB configuration. It is enabled by either selecting the TUI with the
7400 command line option "-i=tui" or by running the separate "gdbtui"
7401 program. For more information on the TUI, see the manual "Debugging
7404 * Pending breakpoint support (also included in GDB 6.1)
7406 Support has been added to allow you to specify breakpoints in shared
7407 libraries that have not yet been loaded. If a breakpoint location
7408 cannot be found, and the "breakpoint pending" option is set to auto,
7409 GDB queries you if you wish to make the breakpoint pending on a future
7410 shared-library load. If and when GDB resolves the breakpoint symbol,
7411 the pending breakpoint is removed as one or more regular breakpoints
7414 Pending breakpoints are very useful for GCJ Java debugging.
7416 * Fixed ISO-C build problems
7418 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
7419 non ISO-C code that stopped them being built using a more strict ISO-C
7420 compiler (e.g., IBM's C compiler).
7422 * Fixed build problem on IRIX 5
7424 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
7425 wasn't able to compile compile on an IRIX 5 system.
7427 * Added execute permission to gdb/gdbserver/configure
7429 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
7430 permission. This bug would cause configure to fail on a number of
7431 systems (Solaris, IRIX). Ref: server/519.
7433 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
7435 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
7436 has been updated to use constant array sizes.
7438 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
7440 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
7441 its generated DWARF Call Frame Info. This encoding was causing GDB to
7442 panic, that panic has been fixed. Ref: gdb/1628.
7444 * Fixed a problem when examining parameters in shared library code.
7446 When examining parameters in optimized shared library code generated
7447 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
7448 not available''. GDB now correctly displays the variable's value.
7450 *** Changes in GDB 6.1:
7452 * Removed --with-mmalloc
7454 Support for the mmalloc memory manager has been removed, as it
7455 conflicted with the internal gdb byte cache.
7457 * Changes in AMD64 configurations
7459 The AMD64 target now includes the %cs and %ss registers. As a result
7460 the AMD64 remote protocol has changed; this affects the floating-point
7461 and SSE registers. If you rely on those registers for your debugging,
7462 you should upgrade gdbserver on the remote side.
7464 * Revised SPARC target
7466 The SPARC target has been completely revised, incorporating the
7467 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
7468 support for LynxOS and SunOS 4 has been dropped. Calling functions
7469 from within GDB on operating systems with a non-executable stack
7470 (Solaris, OpenBSD) now works.
7474 GDB has a new C++ demangler which does a better job on the mangled
7475 names generated by current versions of g++. It also runs faster, so
7476 with this and other changes gdb should now start faster on large C++
7479 * DWARF 2 Location Expressions
7481 GDB support for location expressions has been extended to support function
7482 arguments and frame bases. Older versions of GDB could crash when they
7485 * C++ nested types and namespaces
7487 GDB's support for nested types and namespaces in C++ has been
7488 improved, especially if you use the DWARF 2 debugging format. (This
7489 is the default for recent versions of GCC on most platforms.)
7490 Specifically, if you have a class "Inner" defined within a class or
7491 namespace "Outer", then GDB realizes that the class's name is
7492 "Outer::Inner", not simply "Inner". This should greatly reduce the
7493 frequency of complaints about not finding RTTI symbols. In addition,
7494 if you are stopped at inside of a function defined within a namespace,
7495 GDB modifies its name lookup accordingly.
7497 * New native configurations
7499 NetBSD/amd64 x86_64-*-netbsd*
7500 OpenBSD/amd64 x86_64-*-openbsd*
7501 OpenBSD/alpha alpha*-*-openbsd*
7502 OpenBSD/sparc sparc-*-openbsd*
7503 OpenBSD/sparc64 sparc64-*-openbsd*
7505 * New debugging protocols
7507 M32R with SDI protocol m32r-*-elf*
7509 * "set prompt-escape-char" command deleted.
7511 The command "set prompt-escape-char" has been deleted. This command,
7512 and its very obscure effect on GDB's prompt, was never documented,
7513 tested, nor mentioned in the NEWS file.
7515 * OBSOLETE configurations and files
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 Sun 3, running SunOS 3 m68*-*-sunos3*
7523 Sun 3, running SunOS 4 m68*-*-sunos4*
7524 Sun 2, running SunOS 3 m68000-*-sunos3*
7525 Sun 2, running SunOS 4 m68000-*-sunos4*
7526 Motorola 680x0 running LynxOS m68*-*-lynxos*
7527 AT&T 3b1/Unix pc m68*-att-*
7528 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
7529 decstation mips-dec-* mips-little-*
7530 riscos mips-*-riscos* mips-*-sysv*
7531 sonymips mips-sony-*
7532 sysv mips*-*-sysv4* (IRIX 5/6 not included)
7534 * REMOVED configurations and files
7536 SGI Irix-4.x mips-sgi-irix4 or iris4
7537 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7538 Z8000 simulator z8k-zilog-none or z8ksim
7539 Matsushita MN10200 w/simulator mn10200-*-*
7540 H8/500 simulator h8500-hitachi-hms or h8500hms
7541 HP/PA running BSD hppa*-*-bsd*
7542 HP/PA running OSF/1 hppa*-*-osf*
7543 HP/PA Pro target hppa*-*-pro*
7544 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
7545 386BSD i[3456]86-*-bsd*
7546 Sequent family i[3456]86-sequent-sysv4*
7547 i[3456]86-sequent-sysv*
7548 i[3456]86-sequent-bsd*
7549 SPARC running LynxOS sparc-*-lynxos*
7550 SPARC running SunOS 4 sparc-*-sunos4*
7551 Tsqware Sparclet sparclet-*-*
7552 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7554 *** Changes in GDB 6.0:
7558 Support for debugging the Objective-C programming language has been
7559 integrated into GDB.
7561 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
7563 DWARF 2's Call Frame Information makes available compiler generated
7564 information that more exactly describes the program's run-time stack.
7565 By using this information, GDB is able to provide more robust stack
7568 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
7569 have been updated to use a new backtrace mechanism which includes
7570 DWARF 2 CFI support.
7574 GDB's remote protocol has been extended to include support for hosted
7575 file I/O (where the remote target uses GDB's file system). See GDB's
7576 remote protocol documentation for details.
7578 * All targets using the new architecture framework.
7580 All of GDB's targets have been updated to use the new internal
7581 architecture framework. The way is now open for future GDB releases
7582 to include cross-architecture native debugging support (i386 on amd64,
7585 * GNU/Linux's Thread Local Storage (TLS)
7587 GDB now includes support for for the GNU/Linux implementation of
7588 per-thread variables.
7590 * GNU/Linux's Native POSIX Thread Library (NPTL)
7592 GDB's thread code has been updated to work with either the new
7593 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
7595 * Separate debug info.
7597 GDB, in conjunction with BINUTILS, now supports a mechanism for
7598 automatically loading debug information from a separate file. Instead
7599 of shipping full debug and non-debug versions of system libraries,
7600 system integrators can now instead ship just the stripped libraries
7601 and optional debug files.
7603 * DWARF 2 Location Expressions
7605 DWARF 2 Location Expressions allow the compiler to more completely
7606 describe the location of variables (even in optimized code) to the
7609 GDB now includes preliminary support for location expressions (support
7610 for DW_OP_piece is still missing).
7614 A number of long standing bugs that caused GDB to die while starting a
7615 Java application have been fixed. GDB's Java support is now
7616 considered "usable".
7618 * GNU/Linux support for fork, vfork, and exec.
7620 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
7621 commands are now implemented for GNU/Linux. They require a 2.5.x or later
7624 * GDB supports logging output to a file
7626 There are two new commands, "set logging" and "show logging", which can be
7627 used to capture GDB's output to a file.
7629 * The meaning of "detach" has changed for gdbserver
7631 The "detach" command will now resume the application, as documented. To
7632 disconnect from gdbserver and leave it stopped, use the new "disconnect"
7635 * d10v, m68hc11 `regs' command deprecated
7637 The `info registers' command has been updated so that it displays the
7638 registers using a format identical to the old `regs' command.
7642 A new command, "maint set profile on/off", has been added. This command can
7643 be used to enable or disable profiling while running GDB, to profile a
7644 session or a set of commands. In addition there is a new configure switch,
7645 "--enable-profiling", which will cause GDB to be compiled with profiling
7646 data, for more informative profiling results.
7648 * Default MI syntax changed to "mi2".
7650 The default MI (machine interface) syntax, enabled by the command line
7651 option "-i=mi", has been changed to "mi2". The previous MI syntax,
7652 "mi1", can be enabled by specifying the option "-i=mi1".
7654 Support for the original "mi0" syntax (included in GDB 5.0) has been
7657 Fix for gdb/192: removed extraneous space when displaying frame level.
7658 Fix for gdb/672: update changelist is now output in mi list format.
7659 Fix for gdb/702: a -var-assign that updates the value now shows up
7660 in a subsequent -var-update.
7662 * New native configurations.
7664 FreeBSD/amd64 x86_64-*-freebsd*
7666 * Multi-arched targets.
7668 HP/PA HPUX11 hppa*-*-hpux*
7669 Renesas M32R/D w/simulator m32r-*-elf*
7671 * OBSOLETE configurations and files
7673 Configurations that have been declared obsolete in this release have
7674 been commented out. Unless there is activity to revive these
7675 configurations, the next release of GDB will have their sources
7676 permanently REMOVED.
7678 Z8000 simulator z8k-zilog-none or z8ksim
7679 Matsushita MN10200 w/simulator mn10200-*-*
7680 H8/500 simulator h8500-hitachi-hms or h8500hms
7681 HP/PA running BSD hppa*-*-bsd*
7682 HP/PA running OSF/1 hppa*-*-osf*
7683 HP/PA Pro target hppa*-*-pro*
7684 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
7685 Sequent family i[3456]86-sequent-sysv4*
7686 i[3456]86-sequent-sysv*
7687 i[3456]86-sequent-bsd*
7688 Tsqware Sparclet sparclet-*-*
7689 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
7691 * REMOVED configurations and files
7694 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7695 IBM AIX PS/2 i[3456]86-*-aix
7696 i386 running Mach 3.0 i[3456]86-*-mach3*
7697 i386 running Mach i[3456]86-*-mach*
7698 i386 running OSF/1 i[3456]86-*osf1mk*
7699 HP/Apollo 68k Family m68*-apollo*-sysv*,
7701 m68*-hp-bsd*, m68*-hp-hpux*
7702 Argonaut Risc Chip (ARC) arc-*-*
7703 Mitsubishi D30V d30v-*-*
7704 Fujitsu FR30 fr30-*-elf*
7705 OS/9000 i[34]86-*-os9k
7706 I960 with MON960 i960-*-coff
7708 * MIPS $fp behavior changed
7710 The convenience variable $fp, for the MIPS, now consistently returns
7711 the address of the current frame's base. Previously, depending on the
7712 context, $fp could refer to either $sp or the current frame's base
7713 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
7714 The GNU Source-Level Debugger''.
7716 *** Changes in GDB 5.3:
7718 * GNU/Linux shared library multi-threaded performance improved.
7720 When debugging a multi-threaded application on GNU/Linux, GDB now uses
7721 `/proc', in preference to `ptrace' for memory reads. This may result
7722 in an improvement in the start-up time of multi-threaded, shared
7723 library applications when run under GDB. One GDB user writes: ``loads
7724 shared libs like mad''.
7726 * ``gdbserver'' now supports multi-threaded applications on some targets
7728 Support for debugging multi-threaded applications which use
7729 the GNU/Linux LinuxThreads package has been added for
7730 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
7731 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
7733 * GDB now supports C/C++ preprocessor macros.
7735 GDB now expands preprocessor macro invocations in C/C++ expressions,
7736 and provides various commands for showing macro definitions and how
7739 The new command `macro expand EXPRESSION' expands any macro
7740 invocations in expression, and shows the result.
7742 The new command `show macro MACRO-NAME' shows the definition of the
7743 macro named MACRO-NAME, and where it was defined.
7745 Most compilers don't include information about macros in the debugging
7746 information by default. In GCC 3.1, for example, you need to compile
7747 your program with the options `-gdwarf-2 -g3'. If the macro
7748 information is present in the executable, GDB will read it.
7750 * Multi-arched targets.
7752 DEC Alpha (partial) alpha*-*-*
7753 DEC VAX (partial) vax-*-*
7755 National Semiconductor NS32000 (partial) ns32k-*-*
7756 Motorola 68000 (partial) m68k-*-*
7757 Motorola MCORE mcore-*-*
7761 Fujitsu FRV architecture added by Red Hat frv*-*-*
7764 * New native configurations
7766 Alpha NetBSD alpha*-*-netbsd*
7767 SH NetBSD sh*-*-netbsdelf*
7768 MIPS NetBSD mips*-*-netbsd*
7769 UltraSPARC NetBSD sparc64-*-netbsd*
7771 * OBSOLETE configurations and files
7773 Configurations that have been declared obsolete in this release have
7774 been commented out. Unless there is activity to revive these
7775 configurations, the next release of GDB will have their sources
7776 permanently REMOVED.
7778 Mitsubishi D30V d30v-*-*
7779 OS/9000 i[34]86-*-os9k
7780 IBM AIX PS/2 i[3456]86-*-aix
7781 Fujitsu FR30 fr30-*-elf*
7782 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7783 Argonaut Risc Chip (ARC) arc-*-*
7784 i386 running Mach 3.0 i[3456]86-*-mach3*
7785 i386 running Mach i[3456]86-*-mach*
7786 i386 running OSF/1 i[3456]86-*osf1mk*
7787 HP/Apollo 68k Family m68*-apollo*-sysv*,
7789 m68*-hp-bsd*, m68*-hp-hpux*
7790 I960 with MON960 i960-*-coff
7792 * OBSOLETE languages
7794 CHILL, a Pascal like language used by telecommunications companies.
7796 * REMOVED configurations and files
7798 AMD 29k family via UDI a29k-amd-udi, udi29k
7799 A29K VxWorks a29k-*-vxworks
7800 AMD 29000 embedded, using EBMON a29k-none-none
7801 AMD 29000 embedded with COFF a29k-none-coff
7802 AMD 29000 embedded with a.out a29k-none-aout
7804 testsuite/gdb.hp/gdb.threads-hp/ directory
7806 * New command "set max-user-call-depth <nnn>"
7808 This command allows the user to limit the call depth of user-defined
7809 commands. The default is 1024.
7811 * Changes in FreeBSD/i386 native debugging.
7813 Support for the "generate-core-file" has been added.
7815 * New commands "dump", "append", and "restore".
7817 These commands allow data to be copied from target memory
7818 to a bfd-format or binary file (dump and append), and back
7819 from a file into memory (restore).
7821 * Improved "next/step" support on multi-processor Alpha Tru64.
7823 The previous single-step mechanism could cause unpredictable problems,
7824 including the random appearance of SIGSEGV or SIGTRAP signals. The use
7825 of a software single-step mechanism prevents this.
7827 *** Changes in GDB 5.2.1:
7835 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
7836 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
7837 Fix, by Joel Brobecker imported from mainline.
7839 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
7840 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
7841 Fix, by Fred Fish, imported from mainline.
7843 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
7844 Surprisingly enough, it works now.
7845 By Michal Ludvig, imported from mainline.
7847 i386 hardware watchpoint support:
7848 avoid misses on second run for some targets.
7849 By Pierre Muller, imported from mainline.
7851 *** Changes in GDB 5.2:
7853 * New command "set trust-readonly-sections on[off]".
7855 This command is a hint that tells gdb that read-only sections
7856 really are read-only (ie. that their contents will not change).
7857 In this mode, gdb will go to the object file rather than the
7858 target to read memory from read-only sections (such as ".text").
7859 This can be a significant performance improvement on some
7860 (notably embedded) targets.
7862 * New command "generate-core-file" (or "gcore").
7864 This new gdb command allows the user to drop a core file of the child
7865 process state at any time. So far it's been implemented only for
7866 GNU/Linux and Solaris, but should be relatively easily ported to other
7867 hosts. Argument is core file name (defaults to core.<pid>).
7869 * New command line option
7871 GDB now accepts --pid or -p followed by a process id.
7873 * Change in command line behavior -- corefiles vs. process ids.
7875 There is a subtle behavior in the way in which GDB handles
7876 command line arguments. The first non-flag argument is always
7877 a program to debug, but the second non-flag argument may either
7878 be a corefile or a process id. Previously, GDB would attempt to
7879 open the second argument as a corefile, and if that failed, would
7880 issue a superfluous error message and then attempt to attach it as
7881 a process. Now, if the second argument begins with a non-digit,
7882 it will be treated as a corefile. If it begins with a digit,
7883 GDB will attempt to attach it as a process, and if no such process
7884 is found, will then attempt to open it as a corefile.
7886 * Changes in ARM configurations.
7888 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
7889 configuration is fully multi-arch.
7891 * New native configurations
7893 ARM NetBSD arm*-*-netbsd*
7894 x86 OpenBSD i[3456]86-*-openbsd*
7895 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7896 Sparc64 running FreeBSD sparc64-*-freebsd*
7900 Sanyo XStormy16 xstormy16-elf
7902 * OBSOLETE configurations and files
7904 Configurations that have been declared obsolete in this release have
7905 been commented out. Unless there is activity to revive these
7906 configurations, the next release of GDB will have their sources
7907 permanently REMOVED.
7909 AMD 29k family via UDI a29k-amd-udi, udi29k
7910 A29K VxWorks a29k-*-vxworks
7911 AMD 29000 embedded, using EBMON a29k-none-none
7912 AMD 29000 embedded with COFF a29k-none-coff
7913 AMD 29000 embedded with a.out a29k-none-aout
7915 testsuite/gdb.hp/gdb.threads-hp/ directory
7917 * REMOVED configurations and files
7919 TI TMS320C80 tic80-*-*
7921 PowerPC Solaris powerpcle-*-solaris*
7922 PowerPC Windows NT powerpcle-*-cygwin32
7923 PowerPC Netware powerpc-*-netware*
7924 Harris/CXUX m88k m88*-harris-cxux*
7925 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7926 ns32k-utek-sysv* ns32k-utek-*
7927 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7928 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7929 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7930 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7931 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7933 * Changes to command line processing
7935 The new `--args' feature can be used to specify command-line arguments
7936 for the inferior from gdb's command line.
7938 * Changes to key bindings
7940 There is a new `operate-and-get-next' function bound to `C-o'.
7942 *** Changes in GDB 5.1.1
7944 Fix compile problem on DJGPP.
7946 Fix a problem with floating-point registers on the i386 being
7949 Fix to stop GDB crashing on .debug_str debug info.
7951 Numerous documentation fixes.
7953 Numerous testsuite fixes.
7955 *** Changes in GDB 5.1:
7957 * New native configurations
7959 Alpha FreeBSD alpha*-*-freebsd*
7960 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7961 MIPS GNU/Linux mips*-*-linux*
7962 MIPS SGI Irix 6.x mips*-sgi-irix6*
7963 ia64 AIX ia64-*-aix*
7964 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7968 Motorola 68HC11 and 68HC12 m68hc11-elf
7970 UltraSparc running GNU/Linux sparc64-*-linux*
7972 * OBSOLETE configurations and files
7974 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7975 Harris/CXUX m88k m88*-harris-cxux*
7976 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7977 ns32k-utek-sysv* ns32k-utek-*
7978 TI TMS320C80 tic80-*-*
7980 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7981 PowerPC Solaris powerpcle-*-solaris*
7982 PowerPC Windows NT powerpcle-*-cygwin32
7983 PowerPC Netware powerpc-*-netware*
7984 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7985 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7986 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7987 Apple Macintosh (MPW) host N/A
7989 stuff.c (Program to stuff files into a specially prepared space in kdb)
7990 kdb-start.c (Main loop for the standalone kernel debugger)
7992 Configurations that have been declared obsolete in this release have
7993 been commented out. Unless there is activity to revive these
7994 configurations, the next release of GDB will have their sources
7995 permanently REMOVED.
7997 * REMOVED configurations and files
7999 Altos 3068 m68*-altos-*
8000 Convex c1-*-*, c2-*-*
8002 ARM RISCix arm-*-* (as host)
8006 * GDB has been converted to ISO C.
8008 GDB's source code has been converted to ISO C. In particular, the
8009 sources are fully protoized, and rely on standard headers being
8014 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
8016 * The MI enabled by default.
8018 The new machine oriented interface (MI) introduced in GDB 5.0 has been
8019 revised and enabled by default. Packages which use GDB as a debugging
8020 engine behind a UI or another front end are encouraged to switch to
8021 using the GDB/MI interface, instead of the old annotations interface
8022 which is now deprecated.
8024 * Support for debugging Pascal programs.
8026 GDB now includes support for debugging Pascal programs. The following
8027 main features are supported:
8029 - Pascal-specific data types such as sets;
8031 - automatic recognition of Pascal sources based on file-name
8034 - Pascal-style display of data types, variables, and functions;
8036 - a Pascal expression parser.
8038 However, some important features are not yet supported.
8040 - Pascal string operations are not supported at all;
8042 - there are some problems with boolean types;
8044 - Pascal type hexadecimal constants are not supported
8045 because they conflict with the internal variables format;
8047 - support for Pascal objects and classes is not full yet;
8049 - unlike Pascal, GDB is case-sensitive for symbol names.
8051 * Changes in completion.
8053 Commands such as `shell', `run' and `set args', which pass arguments
8054 to inferior programs, now complete on file names, similar to what
8055 users expect at the shell prompt.
8057 Commands which accept locations, such as `disassemble', `print',
8058 `breakpoint', `until', etc. now complete on filenames as well as
8059 program symbols. Thus, if you type "break foob TAB", and the source
8060 files linked into the programs include `foobar.c', that file name will
8061 be one of the candidates for completion. However, file names are not
8062 considered for completion after you typed a colon that delimits a file
8063 name from a name of a function in that file, as in "break foo.c:bar".
8065 `set demangle-style' completes on available demangling styles.
8067 * New platform-independent commands:
8069 It is now possible to define a post-hook for a command as well as a
8070 hook that runs before the command. For more details, see the
8071 documentation of `hookpost' in the GDB manual.
8073 * Changes in GNU/Linux native debugging.
8075 Support for debugging multi-threaded programs has been completely
8076 revised for all platforms except m68k and sparc. You can now debug as
8077 many threads as your system allows you to have.
8079 Attach/detach is supported for multi-threaded programs.
8081 Support for SSE registers was added for x86. This doesn't work for
8082 multi-threaded programs though.
8084 * Changes in MIPS configurations.
8086 Multi-arch support is enabled for all MIPS configurations.
8088 GDB can now be built as native debugger on SGI Irix 6.x systems for
8089 debugging n32 executables. (Debugging 64-bit executables is not yet
8092 * Unified support for hardware watchpoints in all x86 configurations.
8094 Most (if not all) native x86 configurations support hardware-assisted
8095 breakpoints and watchpoints in a unified manner. This support
8096 implements debug register sharing between watchpoints, which allows to
8097 put a virtually infinite number of watchpoints on the same address,
8098 and also supports watching regions up to 16 bytes with several debug
8101 The new maintenance command `maintenance show-debug-regs' toggles
8102 debugging print-outs in functions that insert, remove, and test
8103 watchpoints and hardware breakpoints.
8105 * Changes in the DJGPP native configuration.
8107 New command ``info dos sysinfo'' displays assorted information about
8108 the CPU, OS, memory, and DPMI server.
8110 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
8111 display information about segment descriptors stored in GDT, LDT, and
8114 New commands ``info dos pde'' and ``info dos pte'' display entries
8115 from Page Directory and Page Tables (for now works with CWSDPMI only).
8116 New command ``info dos address-pte'' displays the Page Table entry for
8117 a given linear address.
8119 GDB can now pass command lines longer than 126 characters to the
8120 program being debugged (requires an update to the libdbg.a library
8121 which is part of the DJGPP development kit).
8123 DWARF2 debug info is now supported.
8125 It is now possible to `step' and `next' through calls to `longjmp'.
8127 * Changes in documentation.
8129 All GDB documentation was converted to GFDL, the GNU Free
8130 Documentation License.
8132 Tracepoints-related commands are now fully documented in the GDB
8135 TUI, the Text-mode User Interface, is now documented in the manual.
8137 Tracepoints-related commands are now fully documented in the GDB
8140 The "GDB Internals" manual now has an index. It also includes
8141 documentation of `ui_out' functions, GDB coding standards, x86
8142 hardware watchpoints, and memory region attributes.
8144 * GDB's version number moved to ``version.in''
8146 The Makefile variable VERSION has been replaced by the file
8147 ``version.in''. People creating GDB distributions should update the
8148 contents of this file.
8152 GUD support is now a standard part of the EMACS distribution.
8154 *** Changes in GDB 5.0:
8156 * Improved support for debugging FP programs on x86 targets
8158 Unified and much-improved support for debugging floating-point
8159 programs on all x86 targets. In particular, ``info float'' now
8160 displays the FP registers in the same format on all x86 targets, with
8161 greater level of detail.
8163 * Improvements and bugfixes in hardware-assisted watchpoints
8165 It is now possible to watch array elements, struct members, and
8166 bitfields with hardware-assisted watchpoints. Data-read watchpoints
8167 on x86 targets no longer erroneously trigger when the address is
8170 * Improvements in the native DJGPP version of GDB
8172 The distribution now includes all the scripts and auxiliary files
8173 necessary to build the native DJGPP version on MS-DOS/MS-Windows
8174 machines ``out of the box''.
8176 The DJGPP version can now debug programs that use signals. It is
8177 possible to catch signals that happened in the debuggee, deliver
8178 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
8179 would kill the program being debugged.) Programs that hook hardware
8180 interrupts (keyboard, timer, etc.) can also be debugged.
8182 It is now possible to debug DJGPP programs that redirect their
8183 standard handles or switch them to raw (as opposed to cooked) mode, or
8184 even close them. The command ``run < foo > bar'' works as expected,
8185 and ``info terminal'' reports useful information about the debuggee's
8186 terminal, including raw/cooked mode, redirection, etc.
8188 The DJGPP version now uses termios functions for console I/O, which
8189 enables debugging graphics programs. Interrupting GDB with Ctrl-C
8192 DOS-style file names with drive letters are now fully supported by
8195 It is now possible to debug DJGPP programs that switch their working
8196 directory. It is also possible to rerun the debuggee any number of
8197 times without restarting GDB; thus, you can use the same setup,
8198 breakpoints, etc. for many debugging sessions.
8200 * New native configurations
8202 ARM GNU/Linux arm*-*-linux*
8203 PowerPC GNU/Linux powerpc-*-linux*
8207 Motorola MCore mcore-*-*
8208 x86 VxWorks i[3456]86-*-vxworks*
8209 PowerPC VxWorks powerpc-*-vxworks*
8210 TI TMS320C80 tic80-*-*
8212 * OBSOLETE configurations
8214 Altos 3068 m68*-altos-*
8215 Convex c1-*-*, c2-*-*
8217 ARM RISCix arm-*-* (as host)
8220 Configurations that have been declared obsolete will be commented out,
8221 but the code will be left in place. If there is no activity to revive
8222 these configurations before the next release of GDB, the sources will
8223 be permanently REMOVED.
8225 * Gould support removed
8227 Support for the Gould PowerNode and NP1 has been removed.
8229 * New features for SVR4
8231 On SVR4 native platforms (such as Solaris), if you attach to a process
8232 without first loading a symbol file, GDB will now attempt to locate and
8233 load symbols from the running process's executable file.
8235 * Many C++ enhancements
8237 C++ support has been greatly improved. Overload resolution now works properly
8238 in almost all cases. RTTI support is on the way.
8240 * Remote targets can connect to a sub-program
8242 A popen(3) style serial-device has been added. This device starts a
8243 sub-process (such as a stand-alone simulator) and then communicates
8244 with that. The sub-program to run is specified using the syntax
8245 ``|<program> <args>'' vis:
8247 (gdb) set remotedebug 1
8248 (gdb) target extended-remote |mn10300-elf-sim program-args
8250 * MIPS 64 remote protocol
8252 A long standing bug in the mips64 remote protocol where by GDB
8253 expected certain 32 bit registers (ex SR) to be transferred as 32
8254 instead of 64 bits has been fixed.
8256 The command ``set remote-mips64-transfers-32bit-regs on'' has been
8257 added to provide backward compatibility with older versions of GDB.
8259 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
8261 The command ``set remotebinarydownload'' command has been replaced by
8262 ``set remote X-packet''. Other commands in ``set remote'' family
8263 include ``set remote P-packet''.
8265 * Breakpoint commands accept ranges.
8267 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
8268 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
8269 ``tracepoint passcount'' also accepts a range of tracepoints.
8271 * ``apropos'' command added.
8273 The ``apropos'' command searches through command names and
8274 documentation strings, printing out matches, making it much easier to
8275 try to find a command that does what you are looking for.
8279 A new machine oriented interface (MI) has been added to GDB. This
8280 interface is designed for debug environments running GDB as a separate
8281 process. This is part of the long term libGDB project. See the
8282 "GDB/MI" chapter of the GDB manual for further information. It can be
8283 enabled by configuring with:
8285 .../configure --enable-gdbmi
8287 *** Changes in GDB-4.18:
8289 * New native configurations
8291 HP-UX 10.20 hppa*-*-hpux10.20
8292 HP-UX 11.x hppa*-*-hpux11.0*
8293 M68K GNU/Linux m68*-*-linux*
8297 Fujitsu FR30 fr30-*-elf*
8298 Intel StrongARM strongarm-*-*
8299 Mitsubishi D30V d30v-*-*
8301 * OBSOLETE configurations
8303 Gould PowerNode, NP1 np1-*-*, pn-*-*
8305 Configurations that have been declared obsolete will be commented out,
8306 but the code will be left in place. If there is no activity to revive
8307 these configurations before the next release of GDB, the sources will
8308 be permanently REMOVED.
8312 As a compatibility experiment, GDB's source files buildsym.h and
8313 buildsym.c have been converted to pure standard C, no longer
8314 containing any K&R compatibility code. We believe that all systems in
8315 use today either come with a standard C compiler, or have a GCC port
8316 available. If this is not true, please report the affected
8317 configuration to bug-gdb@gnu.org immediately. See the README file for
8318 information about getting a standard C compiler if you don't have one
8323 GDB now uses readline 2.2.
8325 * set extension-language
8327 You can now control the mapping between filename extensions and source
8328 languages by using the `set extension-language' command. For instance,
8329 you can ask GDB to treat .c files as C++ by saying
8330 set extension-language .c c++
8331 The command `info extensions' lists all of the recognized extensions
8332 and their associated languages.
8334 * Setting processor type for PowerPC and RS/6000
8336 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
8337 you can use the `set processor' command to specify what variant of the
8338 PowerPC family you are debugging. The command
8342 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
8343 following PowerPC and RS6000 variants:
8345 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
8346 rs6000 IBM RS6000 ("POWER") architecture, user-level view
8348 403GC IBM PowerPC 403GC
8349 505 Motorola PowerPC 505
8350 860 Motorola PowerPC 860 or 850
8351 601 Motorola PowerPC 601
8352 602 Motorola PowerPC 602
8353 603 Motorola/IBM PowerPC 603 or 603e
8354 604 Motorola PowerPC 604 or 604e
8355 750 Motorola/IBM PowerPC 750 or 750
8357 At the moment, this command just tells GDB what to name the
8358 special-purpose processor registers. Since almost all the affected
8359 registers are inaccessible to user-level programs, this command is
8360 only useful for remote debugging in its present form.
8364 Thanks to a major code donation from Hewlett-Packard, GDB now has much
8365 more extensive support for HP-UX. Added features include shared
8366 library support, kernel threads and hardware watchpoints for 11.00,
8367 support for HP's ANSI C and C++ compilers, and a compatibility mode
8368 for xdb and dbx commands.
8372 HP's donation includes the new concept of catchpoints, which is a
8373 generalization of the old catch command. On HP-UX, it is now possible
8374 to catch exec, fork, and vfork, as well as library loading.
8376 This means that the existing catch command has changed; its first
8377 argument now specifies the type of catch to be set up. See the
8378 output of "help catch" for a list of catchpoint types.
8380 * Debugging across forks
8382 On HP-UX, you can choose which process to debug when a fork() happens
8387 HP has donated a curses-based terminal user interface (TUI). To get
8388 it, build with --enable-tui. Although this can be enabled for any
8389 configuration, at present it only works for native HP debugging.
8391 * GDB remote protocol additions
8393 A new protocol packet 'X' that writes binary data is now available.
8394 Default behavior is to try 'X', then drop back to 'M' if the stub
8395 fails to respond. The settable variable `remotebinarydownload'
8396 allows explicit control over the use of 'X'.
8398 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
8399 full 64-bit address. The command
8401 set remoteaddresssize 32
8403 can be used to revert to the old behavior. For existing remote stubs
8404 the change should not be noticed, as the additional address information
8407 In order to assist in debugging stubs, you may use the maintenance
8408 command `packet' to send any text string to the stub. For instance,
8410 maint packet heythere
8412 sends the packet "$heythere#<checksum>". Note that it is very easy to
8413 disrupt a debugging session by sending the wrong packet at the wrong
8416 The compare-sections command allows you to compare section data on the
8417 target to what is in the executable file without uploading or
8418 downloading, by comparing CRC checksums.
8420 * Tracing can collect general expressions
8422 You may now collect general expressions at tracepoints. This requires
8423 further additions to the target-side stub; see tracepoint.c and
8424 doc/agentexpr.texi for further details.
8426 * mask-address variable for Mips
8428 For Mips targets, you may control the zeroing of the upper 32 bits of
8429 a 64-bit address by entering `set mask-address on'. This is mainly
8430 of interest to users of embedded R4xxx and R5xxx processors.
8432 * Higher serial baud rates
8434 GDB's serial code now allows you to specify baud rates 57600, 115200,
8435 230400, and 460800 baud. (Note that your host system may not be able
8436 to achieve all of these rates.)
8440 The i960 configuration now includes an initial implementation of a
8441 builtin simulator, contributed by Jim Wilson.
8444 *** Changes in GDB-4.17:
8446 * New native configurations
8448 Alpha GNU/Linux alpha*-*-linux*
8449 Unixware 2.x i[3456]86-unixware2*
8450 Irix 6.x mips*-sgi-irix6*
8451 PowerPC GNU/Linux powerpc-*-linux*
8452 PowerPC Solaris powerpcle-*-solaris*
8453 Sparc GNU/Linux sparc-*-linux*
8454 Motorola sysV68 R3V7.1 m68k-motorola-sysv
8458 Argonaut Risc Chip (ARC) arc-*-*
8459 Hitachi H8/300S h8300*-*-*
8460 Matsushita MN10200 w/simulator mn10200-*-*
8461 Matsushita MN10300 w/simulator mn10300-*-*
8462 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
8463 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
8464 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
8465 Mitsubishi D10V w/simulator d10v-*-*
8466 Mitsubishi M32R/D w/simulator m32r-*-elf*
8467 Tsqware Sparclet sparclet-*-*
8468 NEC V850 w/simulator v850-*-*
8470 * New debugging protocols
8472 ARM with RDI protocol arm*-*-*
8473 M68K with dBUG monitor m68*-*-{aout,coff,elf}
8474 DDB and LSI variants of PMON protocol mips*-*-*
8475 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
8476 PowerPC with SDS protocol powerpc{,le}-*-eabi
8477 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
8481 All configurations can now understand and use the DWARF 2 debugging
8482 format. The choice is automatic, if the symbol file contains DWARF 2
8487 GDB now includes basic Java language support. This support is
8488 only useful with Java compilers that produce native machine code.
8490 * solib-absolute-prefix and solib-search-path
8492 For SunOS and SVR4 shared libraries, you may now set the prefix for
8493 loading absolute shared library symbol files, and the search path for
8494 locating non-absolute shared library symbol files.
8496 * Live range splitting
8498 GDB can now effectively debug code for which GCC has performed live
8499 range splitting as part of its optimization. See gdb/doc/LRS for
8500 more details on the expected format of the stabs information.
8504 GDB's support for the GNU Hurd, including thread debugging, has been
8505 updated to work with current versions of the Hurd.
8509 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
8510 instruction set. ARM GDB automatically detects when Thumb
8511 instructions are in use, and adjusts disassembly and backtracing
8516 GDB's MIPS target configurations now handle the MIP16 16-bit
8521 GDB now includes support for overlays; if an executable has been
8522 linked such that multiple sections are based at the same address, GDB
8523 will decide which section to use for symbolic info. You can choose to
8524 control the decision manually, using overlay commands, or implement
8525 additional target-side support and use "overlay load-target" to bring
8526 in the overlay mapping. Do "help overlay" for more detail.
8530 The command "info symbol <address>" displays information about
8531 the symbol at the specified address.
8535 The standard remote protocol now includes an extension that allows
8536 asynchronous collection and display of trace data. This requires
8537 extensive support in the target-side debugging stub. Tracing mode
8538 includes a new interaction mode in GDB and new commands: see the
8539 file tracepoint.c for more details.
8543 Configurations for embedded MIPS now include a simulator contributed
8544 by Cygnus Solutions. The simulator supports the instruction sets
8545 of most MIPS variants.
8549 Sparc configurations may now include the ERC32 simulator contributed
8550 by the European Space Agency. The simulator is not built into
8551 Sparc targets by default; configure with --enable-sim to include it.
8555 For target configurations that may include multiple variants of a
8556 basic architecture (such as MIPS and SH), you may now set the
8557 architecture explicitly. "set arch" sets, "info arch" lists
8558 the possible architectures.
8560 *** Changes in GDB-4.16:
8562 * New native configurations
8564 Windows 95, x86 Windows NT i[345]86-*-cygwin32
8565 M68K NetBSD m68k-*-netbsd*
8566 PowerPC AIX 4.x powerpc-*-aix*
8567 PowerPC MacOS powerpc-*-macos*
8568 PowerPC Windows NT powerpcle-*-cygwin32
8569 RS/6000 AIX 4.x rs6000-*-aix4*
8573 ARM with RDP protocol arm-*-*
8574 I960 with MON960 i960-*-coff
8575 MIPS VxWorks mips*-*-vxworks*
8576 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
8577 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
8579 Matra Sparclet sparclet-*-*
8583 The powerpc-eabi configuration now includes the PSIM simulator,
8584 contributed by Andrew Cagney, with assistance from Mike Meissner.
8585 PSIM is a very elaborate model of the PowerPC, including not only
8586 basic instruction set execution, but also details of execution unit
8587 performance and I/O hardware. See sim/ppc/README for more details.
8591 GDB now works with Solaris 2.5.
8593 * Windows 95/NT native
8595 GDB will now work as a native debugger on Windows 95 and Windows NT.
8596 To build it from source, you must use the "gnu-win32" environment,
8597 which uses a DLL to emulate enough of Unix to run the GNU tools.
8598 Further information, binaries, and sources are available at
8599 ftp.cygnus.com, under pub/gnu-win32.
8601 * dont-repeat command
8603 If a user-defined command includes the command `dont-repeat', then the
8604 command will not be repeated if the user just types return. This is
8605 useful if the command is time-consuming to run, so that accidental
8606 extra keystrokes don't run the same command many times.
8608 * Send break instead of ^C
8610 The standard remote protocol now includes an option to send a break
8611 rather than a ^C to the target in order to interrupt it. By default,
8612 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
8614 * Remote protocol timeout
8616 The standard remote protocol includes a new variable `remotetimeout'
8617 that allows you to set the number of seconds before GDB gives up trying
8618 to read from the target. The default value is 2.
8620 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
8622 By default GDB will automatically keep track of objects as they are
8623 loaded and unloaded by the dynamic linker. By using the command `set
8624 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
8625 when shared library events occur, thus allowing you to set breakpoints
8626 in shared libraries which are explicitly loaded by the inferior.
8628 Note this feature does not work on hpux8. On hpux9 you must link
8629 /usr/lib/end.o into your program. This feature should work
8630 automatically on hpux10.
8632 * Irix 5.x hardware watchpoint support
8634 Irix 5 configurations now support the use of hardware watchpoints.
8636 * Mips protocol "SYN garbage limit"
8638 When debugging a Mips target using the `target mips' protocol, you
8639 may set the number of characters that GDB will ignore by setting
8640 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
8641 every character. The default value is 1050.
8643 * Recording and replaying remote debug sessions
8645 If you set `remotelogfile' to the name of a file, gdb will write to it
8646 a recording of a remote debug session. This recording may then be
8647 replayed back to gdb using "gdbreplay". See gdbserver/README for
8648 details. This is useful when you have a problem with GDB while doing
8649 remote debugging; you can make a recording of the session and send it
8650 to someone else, who can then recreate the problem.
8652 * Speedups for remote debugging
8654 GDB includes speedups for downloading and stepping MIPS systems using
8655 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
8656 and more efficient S-record downloading.
8658 * Memory use reductions and statistics collection
8660 GDB now uses less memory and reports statistics about memory usage.
8661 Try the `maint print statistics' command, for example.
8663 *** Changes in GDB-4.15:
8665 * Psymtabs for XCOFF
8667 The symbol reader for AIX GDB now uses partial symbol tables. This
8668 can greatly improve startup time, especially for large executables.
8670 * Remote targets use caching
8672 Remote targets now use a data cache to speed up communication with the
8673 remote side. The data cache could lead to incorrect results because
8674 it doesn't know about volatile variables, thus making it impossible to
8675 debug targets which use memory mapped I/O devices. `set remotecache
8676 off' turns the data cache off.
8678 * Remote targets may have threads
8680 The standard remote protocol now includes support for multiple threads
8681 in the target system, using new protocol commands 'H' and 'T'. See
8682 gdb/remote.c for details.
8686 If GDB is configured with `--enable-netrom', then it will include
8687 support for the NetROM ROM emulator from XLNT Designs. The NetROM
8688 acts as though it is a bank of ROM on the target board, but you can
8689 write into it over the network. GDB's support consists only of
8690 support for fast loading into the emulated ROM; to debug, you must use
8691 another protocol, such as standard remote protocol. The usual
8692 sequence is something like
8694 target nrom <netrom-hostname>
8696 target remote <netrom-hostname>:1235
8700 GDB now includes support for the Apple Macintosh, as a host only. It
8701 may be run as either an MPW tool or as a standalone application, and
8702 it can debug through the serial port. All the usual GDB commands are
8703 available, but to the target command, you must supply "serial" as the
8704 device type instead of "/dev/ttyXX". See mpw-README in the main
8705 directory for more information on how to build. The MPW configuration
8706 scripts */mpw-config.in support only a few targets, and only the
8707 mips-idt-ecoff target has been tested.
8711 GDB configuration now uses autoconf. This is not user-visible,
8712 but does simplify configuration and building.
8716 GDB now supports hpux10.
8718 *** Changes in GDB-4.14:
8720 * New native configurations
8722 x86 FreeBSD i[345]86-*-freebsd
8723 x86 NetBSD i[345]86-*-netbsd
8724 NS32k NetBSD ns32k-*-netbsd
8725 Sparc NetBSD sparc-*-netbsd
8729 A29K VxWorks a29k-*-vxworks
8730 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
8731 CPU32 EST-300 emulator m68*-*-est*
8732 PowerPC ELF powerpc-*-elf
8735 * Alpha OSF/1 support for procfs
8737 GDB now supports procfs under OSF/1-2.x and higher, which makes it
8738 possible to attach to running processes. As the mounting of the /proc
8739 filesystem is optional on the Alpha, GDB automatically determines
8740 the availability of /proc during startup. This can lead to problems
8741 if /proc is unmounted after GDB has been started.
8743 * Arguments to user-defined commands
8745 User commands may accept up to 10 arguments separated by whitespace.
8746 Arguments are accessed within the user command via $arg0..$arg9. A
8749 print $arg0 + $arg1 + $arg2
8751 To execute the command use:
8754 Defines the command "adder" which prints the sum of its three arguments.
8755 Note the arguments are text substitutions, so they may reference variables,
8756 use complex expressions, or even perform inferior function calls.
8758 * New `if' and `while' commands
8760 This makes it possible to write more sophisticated user-defined
8761 commands. Both commands take a single argument, which is the
8762 expression to evaluate, and must be followed by the commands to
8763 execute, one per line, if the expression is nonzero, the list being
8764 terminated by the word `end'. The `if' command list may include an
8765 `else' word, which causes the following commands to be executed only
8766 if the expression is zero.
8768 * Fortran source language mode
8770 GDB now includes partial support for Fortran 77. It will recognize
8771 Fortran programs and can evaluate a subset of Fortran expressions, but
8772 variables and functions may not be handled correctly. GDB will work
8773 with G77, but does not yet know much about symbols emitted by other
8776 * Better HPUX support
8778 Most debugging facilities now work on dynamic executables for HPPAs
8779 running hpux9 or later. You can attach to running dynamically linked
8780 processes, but by default the dynamic libraries will be read-only, so
8781 for instance you won't be able to put breakpoints in them. To change
8782 that behavior do the following before running the program:
8788 This will cause the libraries to be mapped private and read-write.
8789 To revert to the normal behavior, do this:
8795 You cannot set breakpoints or examine data in the library until after
8796 the library is loaded if the function/data symbols do not have
8799 GDB can now also read debug symbols produced by the HP C compiler on
8800 HPPAs (sorry, no C++, Fortran or 68k support).
8802 * Target byte order now dynamically selectable
8804 You can choose which byte order to use with a target system, via the
8805 commands "set endian big" and "set endian little", and you can see the
8806 current setting by using "show endian". You can also give the command
8807 "set endian auto", in which case GDB will use the byte order
8808 associated with the executable. Currently, only embedded MIPS
8809 configurations support dynamic selection of target byte order.
8811 * New DOS host serial code
8813 This version uses DPMI interrupts to handle buffered I/O, so you
8814 no longer need to run asynctsr when debugging boards connected to
8817 *** Changes in GDB-4.13:
8819 * New "complete" command
8821 This lists all the possible completions for the rest of the line, if it
8822 were to be given as a command itself. This is intended for use by emacs.
8824 * Trailing space optional in prompt
8826 "set prompt" no longer adds a space for you after the prompt you set. This
8827 allows you to set a prompt which ends in a space or one that does not.
8829 * Breakpoint hit counts
8831 "info break" now displays a count of the number of times the breakpoint
8832 has been hit. This is especially useful in conjunction with "ignore"; you
8833 can ignore a large number of breakpoint hits, look at the breakpoint info
8834 to see how many times the breakpoint was hit, then run again, ignoring one
8835 less than that number, and this will get you quickly to the last hit of
8838 * Ability to stop printing at NULL character
8840 "set print null-stop" will cause GDB to stop printing the characters of
8841 an array when the first NULL is encountered. This is useful when large
8842 arrays actually contain only short strings.
8844 * Shared library breakpoints
8846 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
8847 breakpoints in shared libraries before the executable is run.
8849 * Hardware watchpoints
8851 There is a new hardware breakpoint for the watch command for sparclite
8852 targets. See gdb/sparclite/hw_breakpoint.note.
8854 Hardware watchpoints are also now supported under GNU/Linux.
8858 Annotations have been added. These are for use with graphical interfaces,
8859 and are still experimental. Currently only gdba.el uses these.
8861 * Improved Irix 5 support
8863 GDB now works properly with Irix 5.2.
8865 * Improved HPPA support
8867 GDB now works properly with the latest GCC and GAS.
8869 * New native configurations
8871 Sequent PTX4 i[34]86-sequent-ptx4
8872 HPPA running OSF/1 hppa*-*-osf*
8873 Atari TT running SVR4 m68*-*-sysv4*
8874 RS/6000 LynxOS rs6000-*-lynxos*
8878 OS/9000 i[34]86-*-os9k
8879 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
8882 * Hitachi SH7000 and E7000-PC ICE support
8884 There is now support for communicating with the Hitachi E7000-PC ICE.
8885 This is available automatically when GDB is configured for the SH.
8889 As usual, a variety of small fixes and improvements, both generic
8890 and configuration-specific. See the ChangeLog for more detail.
8892 *** Changes in GDB-4.12:
8894 * Irix 5 is now supported
8898 GDB-4.12 on the HPPA has a number of changes which make it unable
8899 to debug the output from the currently released versions of GCC and
8900 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8901 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8902 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8905 *** Changes in GDB-4.11:
8907 * User visible changes:
8911 The "set remotedebug" option is now consistent between the mips remote
8912 target, remote targets using the gdb-specific protocol, UDI (AMD's
8913 debug protocol for the 29k) and the 88k bug monitor. It is now an
8914 integer specifying a debug level (normally 0 or 1, but 2 means more
8915 debugging info for the mips target).
8917 * DEC Alpha native support
8919 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8920 debug info, but GDB works fairly well with the DEC compiler and should
8921 work with a future GCC release. See the README file for a few
8922 Alpha-specific notes.
8924 * Preliminary thread implementation
8926 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8928 * LynxOS native and target support for 386
8930 This release has been hosted on LynxOS 2.2, and also can be configured
8931 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8934 * Improvements in C++ mangling/demangling.
8936 This release has much better g++ debugging, specifically in name
8937 mangling/demangling, virtual function calls, print virtual table,
8938 call methods, ...etc.
8940 *** Changes in GDB-4.10:
8942 * User visible changes:
8944 Remote debugging using the GDB-specific (`target remote') protocol now
8945 supports the `load' command. This is only useful if you have some
8946 other way of getting the stub to the target system, and you can put it
8947 somewhere in memory where it won't get clobbered by the download.
8949 Filename completion now works.
8951 When run under emacs mode, the "info line" command now causes the
8952 arrow to point to the line specified. Also, "info line" prints
8953 addresses in symbolic form (as well as hex).
8955 All vxworks based targets now support a user settable option, called
8956 vxworks-timeout. This option represents the number of seconds gdb
8957 should wait for responses to rpc's. You might want to use this if
8958 your vxworks target is, perhaps, a slow software simulator or happens
8959 to be on the far side of a thin network line.
8963 This release contains support for using a DEC alpha as a GDB host for
8964 cross debugging. Native alpha debugging is not supported yet.
8967 *** Changes in GDB-4.9:
8971 This is the first GDB release which is accompanied by a matching testsuite.
8972 The testsuite requires installation of dejagnu, which should be available
8973 via ftp from most sites that carry GNU software.
8977 'Cfront' style demangling has had its name changed to 'ARM' style, to
8978 emphasize that it was written from the specifications in the C++ Annotated
8979 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8980 disclaimers, it still generated too much confusion with users attempting to
8981 use gdb with AT&T cfront.
8985 GDB now uses a standard remote interface to a simulator library.
8986 So far, the library contains simulators for the Zilog Z8001/2, the
8987 Hitachi H8/300, H8/500 and Super-H.
8989 * New targets supported
8991 H8/300 simulator h8300-hitachi-hms or h8300hms
8992 H8/500 simulator h8500-hitachi-hms or h8500hms
8993 SH simulator sh-hitachi-hms or sh
8994 Z8000 simulator z8k-zilog-none or z8ksim
8995 IDT MIPS board over serial line mips-idt-ecoff
8997 Cross-debugging to GO32 targets is supported. It requires a custom
8998 version of the i386-stub.c module which is integrated with the
8999 GO32 memory extender.
9001 * New remote protocols
9003 MIPS remote debugging protocol.
9005 * New source languages supported
9007 This version includes preliminary support for Chill, a Pascal like language
9008 used by telecommunications companies. Chill support is also being integrated
9009 into the GNU compiler, but we don't know when it will be publicly available.
9012 *** Changes in GDB-4.8:
9014 * HP Precision Architecture supported
9016 GDB now supports HP PA-RISC machines running HPUX. A preliminary
9017 version of this support was available as a set of patches from the
9018 University of Utah. GDB does not support debugging of programs
9019 compiled with the HP compiler, because HP will not document their file
9020 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
9021 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
9023 Many problems in the preliminary version have been fixed.
9025 * Faster and better demangling
9027 We have improved template demangling and fixed numerous bugs in the GNU style
9028 demangler. It can now handle type modifiers such as `static' or `const'. Wide
9029 character types (wchar_t) are now supported. Demangling of each symbol is now
9030 only done once, and is cached when the symbol table for a file is read in.
9031 This results in a small increase in memory usage for C programs, a moderate
9032 increase in memory usage for C++ programs, and a fantastic speedup in
9035 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
9036 from the specifications in the Annotated Reference Manual, which AT&T's
9037 compiler does not actually implement.
9039 * G++ multiple inheritance compiler problem
9041 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
9042 inheritance lattices was reworked to properly discover ambiguities. We
9043 recently found an example which causes this new algorithm to fail in a
9044 very subtle way, producing bad debug information for those classes.
9045 The file 'gcc.patch' (in this directory) can be applied to gcc to
9046 circumvent the problem. A future GCC release will contain a complete
9049 The previous G++ debug info problem (mentioned below for the gdb-4.7
9050 release) is fixed in gcc version 2.3.2.
9052 * Improved configure script
9054 The `configure' script will now attempt to guess your system type if
9055 you don't supply a host system type. The old scheme of supplying a
9056 host system triplet is preferable over using this. All the magic is
9057 done in the new `config.guess' script. Examine it for details.
9059 We have also brought our configure script much more in line with the FSF's
9060 version. It now supports the --with-xxx options. In particular,
9061 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
9062 The resulting GDB will not be able to read arbitrary object file formats --
9063 only the format ``expected'' to be used on the configured target system.
9064 We hope to make this the default in a future release.
9066 * Documentation improvements
9068 There's new internal documentation on how to modify GDB, and how to
9069 produce clean changes to the code. We implore people to read it
9070 before submitting changes.
9072 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
9073 M4 macros. The new texinfo.tex is provided in this release. Pre-built
9074 `info' files are also provided. To build `info' files from scratch,
9075 you will need the latest `makeinfo' release, which will be available in
9076 a future texinfo-X.Y release.
9078 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
9079 We're not sure exactly which versions have this problem, but it has
9080 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
9081 or better. If that isn't possible, there is a patch in
9082 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
9083 around this problem.
9087 GDB now supports array constants that can be used in expressions typed in by
9088 the user. The syntax is `{element, element, ...}'. Ie: you can now type
9089 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
9092 The new directory `gdb/sparclite' contains a program that demonstrates
9093 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
9095 * New native hosts supported
9097 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
9098 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
9100 * New targets supported
9102 AMD 29k family via UDI a29k-amd-udi or udi29k
9104 * New file formats supported
9106 BFD now supports reading HP/PA-RISC executables (SOM file format?),
9107 HPUX core files, and SCO 3.2v2 core files.
9111 Attaching to processes now works again; thanks for the many bug reports.
9113 We have also stomped on a bunch of core dumps caused by
9114 printf_filtered("%s") problems.
9116 We eliminated a copyright problem on the rpc and ptrace header files
9117 for VxWorks, which was discovered at the last minute during the 4.7
9118 release. You should now be able to build a VxWorks GDB.
9120 You can now interrupt gdb while an attached process is running. This
9121 will cause the attached process to stop, and give control back to GDB.
9123 We fixed problems caused by using too many file descriptors
9124 for reading symbols from object files and libraries. This was
9125 especially a problem for programs that used many (~100) shared
9128 The `step' command now only enters a subroutine if there is line number
9129 information for the subroutine. Otherwise it acts like the `next'
9130 command. Previously, `step' would enter subroutines if there was
9131 any debugging information about the routine. This avoids problems
9132 when using `cc -g1' on MIPS machines.
9134 * Internal improvements
9136 GDB's internal interfaces have been improved to make it easier to support
9137 debugging of multiple languages in the future.
9139 GDB now uses a common structure for symbol information internally.
9140 Minimal symbols (derived from linkage symbols in object files), partial
9141 symbols (from a quick scan of debug information), and full symbols
9142 contain a common subset of information, making it easier to write
9143 shared code that handles any of them.
9145 * New command line options
9147 We now accept --silent as an alias for --quiet.
9151 The memory-mapped-malloc library is now licensed under the GNU Library
9152 General Public License.
9154 *** Changes in GDB-4.7:
9156 * Host/native/target split
9158 GDB has had some major internal surgery to untangle the support for
9159 hosts and remote targets. Now, when you configure GDB for a remote
9160 target, it will no longer load in all of the support for debugging
9161 local programs on the host. When fully completed and tested, this will
9162 ensure that arbitrary host/target combinations are possible.
9164 The primary conceptual shift is to separate the non-portable code in
9165 GDB into three categories. Host specific code is required any time GDB
9166 is compiled on that host, regardless of the target. Target specific
9167 code relates to the peculiarities of the target, but can be compiled on
9168 any host. Native specific code is everything else: it can only be
9169 built when the host and target are the same system. Child process
9170 handling and core file support are two common `native' examples.
9172 GDB's use of /proc for controlling Unix child processes is now cleaner.
9173 It has been split out into a single module under the `target_ops' vector,
9174 plus two native-dependent functions for each system that uses /proc.
9176 * New hosts supported
9178 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
9179 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
9180 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
9182 * New targets supported
9184 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
9185 68030 and CPU32 m68030-*-*, m68332-*-*
9187 * New native hosts supported
9189 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
9190 (386bsd is not well tested yet)
9191 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
9193 * New file formats supported
9195 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
9196 supports reading of `a.out.adobe' object files, which are an a.out
9197 format extended with minimal information about multiple sections.
9201 `show copying' is the same as the old `info copying'.
9202 `show warranty' is the same as `info warrantee'.
9203 These were renamed for consistency. The old commands continue to work.
9205 `info handle' is a new alias for `info signals'.
9207 You can now define pre-command hooks, which attach arbitrary command
9208 scripts to any command. The commands in the hook will be executed
9209 prior to the user's command. You can also create a hook which will be
9210 executed whenever the program stops. See gdb.texinfo.
9214 We now deal with Cfront style name mangling, and can even extract type
9215 info from mangled symbols. GDB can automatically figure out which
9216 symbol mangling style your C++ compiler uses.
9218 Calling of methods and virtual functions has been improved as well.
9222 The crash that occurred when debugging Sun Ansi-C compiled binaries is
9223 fixed. This was due to mishandling of the extra N_SO stabs output
9226 We also finally got Ultrix 4.2 running in house, and fixed core file
9227 support, with help from a dozen people on the net.
9229 John M. Farrell discovered that the reason that single-stepping was so
9230 slow on all of the Mips based platforms (primarily SGI and DEC) was
9231 that we were trying to demangle and lookup a symbol used for internal
9232 purposes on every instruction that was being stepped through. Changing
9233 the name of that symbol so that it couldn't be mistaken for a C++
9234 mangled symbol sped things up a great deal.
9236 Rich Pixley sped up symbol lookups in general by getting much smarter
9237 about when C++ symbol mangling is necessary. This should make symbol
9238 completion (TAB on the command line) much faster. It's not as fast as
9239 we'd like, but it's significantly faster than gdb-4.6.
9243 A new user controllable variable 'call_scratch_address' can
9244 specify the location of a scratch area to be used when GDB
9245 calls a function in the target. This is necessary because the
9246 usual method of putting the scratch area on the stack does not work
9247 in systems that have separate instruction and data spaces.
9249 We integrated changes to support the 29k UDI (Universal Debugger
9250 Interface), but discovered at the last minute that we didn't have all
9251 of the appropriate copyright paperwork. We are working with AMD to
9252 resolve this, and hope to have it available soon.
9256 We have sped up the remote serial line protocol, especially for targets
9257 with lots of registers. It now supports a new `expedited status' ('T')
9258 message which can be used in place of the existing 'S' status message.
9259 This allows the remote stub to send only the registers that GDB
9260 needs to make a quick decision about single-stepping or conditional
9261 breakpoints, eliminating the need to fetch the entire register set for
9262 each instruction being stepped through.
9264 The GDB remote serial protocol now implements a write-through cache for
9265 registers, only re-reading the registers if the target has run.
9267 There is also a new remote serial stub for SPARC processors. You can
9268 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
9269 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
9270 processor with a serial port.
9274 Configure.in files have become much easier to read and modify. A new
9275 `table driven' format makes it more obvious what configurations are
9276 supported, and what files each one uses.
9280 There is a new opcodes library which will eventually contain all of the
9281 disassembly routines and opcode tables. At present, it only contains
9282 Sparc and Z8000 routines. This will allow the assembler, debugger, and
9283 disassembler (binutils/objdump) to share these routines.
9285 The libiberty library is now copylefted under the GNU Library General
9286 Public License. This allows more liberal use, and was done so libg++
9287 can use it. This makes no difference to GDB, since the Library License
9288 grants all the rights from the General Public License.
9292 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
9293 reference to the stabs symbol info used by the debugger. It is (as far
9294 as we know) the only published document on this fascinating topic. We
9295 encourage you to read it, compare it to the stabs information on your
9296 system, and send improvements on the document in general (to
9297 bug-gdb@prep.ai.mit.edu).
9299 And, of course, many bugs have been fixed.
9302 *** Changes in GDB-4.6:
9304 * Better support for C++ function names
9306 GDB now accepts as input the "demangled form" of C++ overloaded function
9307 names and member function names, and can do command completion on such names
9308 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
9309 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
9310 Make use of command completion, it is your friend.
9312 GDB also now accepts a variety of C++ mangled symbol formats. They are
9313 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
9314 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
9315 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
9316 for the list of formats.
9318 * G++ symbol mangling problem
9320 Recent versions of gcc have a bug in how they emit debugging information for
9321 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
9322 directory) can be applied to gcc to fix the problem. Alternatively, if you
9323 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
9324 usual symptom is difficulty with setting breakpoints on methods. GDB complains
9325 about the method being non-existent. (We believe that version 2.2.2 of GCC has
9328 * New 'maintenance' command
9330 All of the commands related to hacking GDB internals have been moved out of
9331 the main command set, and now live behind the 'maintenance' command. This
9332 can also be abbreviated as 'mt'. The following changes were made:
9334 dump-me -> maintenance dump-me
9335 info all-breakpoints -> maintenance info breakpoints
9336 printmsyms -> maintenance print msyms
9337 printobjfiles -> maintenance print objfiles
9338 printpsyms -> maintenance print psymbols
9339 printsyms -> maintenance print symbols
9341 The following commands are new:
9343 maintenance demangle Call internal GDB demangler routine to
9344 demangle a C++ link name and prints the result.
9345 maintenance print type Print a type chain for a given symbol
9347 * Change to .gdbinit file processing
9349 We now read the $HOME/.gdbinit file before processing the argv arguments
9350 (e.g. reading symbol files or core files). This allows global parameters to
9351 be set, which will apply during the symbol reading. The ./.gdbinit is still
9352 read after argv processing.
9354 * New hosts supported
9356 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
9358 GNU/Linux support i386-unknown-linux or linux
9360 We are also including code to support the HP/PA running BSD and HPUX. This
9361 is almost guaranteed not to work, as we didn't have time to test or build it
9362 for this release. We are including it so that the more adventurous (or
9363 masochistic) of you can play with it. We also had major problems with the
9364 fact that the compiler that we got from HP doesn't support the -g option.
9367 * New targets supported
9369 Hitachi H8/300 h8300-hitachi-hms or h8300hms
9371 * More smarts about finding #include files
9373 GDB now remembers the compilation directory for all include files, and for
9374 all files from which C is generated (like yacc and lex sources). This
9375 greatly improves GDB's ability to find yacc/lex sources, and include files,
9376 especially if you are debugging your program from a directory different from
9377 the one that contains your sources.
9379 We also fixed a bug which caused difficulty with listing and setting
9380 breakpoints in include files which contain C code. (In the past, you had to
9381 try twice in order to list an include file that you hadn't looked at before.)
9383 * Interesting infernals change
9385 GDB now deals with arbitrary numbers of sections, where the symbols for each
9386 section must be relocated relative to that section's landing place in the
9387 target's address space. This work was needed to support ELF with embedded
9388 stabs used by Solaris-2.0.
9390 * Bug fixes (of course!)
9392 There have been loads of fixes for the following things:
9393 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
9394 i960, stabs, DOS(GO32), procfs, etc...
9396 See the ChangeLog for details.
9398 *** Changes in GDB-4.5:
9400 * New machines supported (host and target)
9402 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
9404 SGI Irix-4.x mips-sgi-irix4 or iris4
9406 * New malloc package
9408 GDB now uses a new memory manager called mmalloc, based on gmalloc.
9409 Mmalloc is capable of handling multiple heaps of memory. It is also
9410 capable of saving a heap to a file, and then mapping it back in later.
9411 This can be used to greatly speedup the startup of GDB by using a
9412 pre-parsed symbol table which lives in a mmalloc managed heap. For
9413 more details, please read mmalloc/mmalloc.texi.
9417 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
9418 'help info proc' for details.
9420 * MIPS ecoff symbol table format
9422 The code that reads MIPS symbol table format is now supported on all hosts.
9423 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
9426 * File name changes for MS-DOS
9428 Many files in the config directories have been renamed to make it easier to
9429 support GDB on MS-DOSe systems (which have very restrictive file name
9430 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
9431 environment) is close to working but has some remaining problems. Note
9432 that debugging of DOS programs is not supported, due to limitations
9433 in the ``operating system'', but it can be used to host cross-debugging.
9435 * Cross byte order fixes
9437 Many fixes have been made to support cross debugging of Sparc and MIPS
9438 targets from hosts whose byte order differs.
9440 * New -mapped and -readnow options
9442 If memory-mapped files are available on your system through the 'mmap'
9443 system call, you can use the -mapped option on the `file' or
9444 `symbol-file' commands to cause GDB to write the symbols from your
9445 program into a reusable file. If the program you are debugging is
9446 called `/path/fred', the mapped symbol file will be `./fred.syms'.
9447 Future GDB debugging sessions will notice the presence of this file,
9448 and will quickly map in symbol information from it, rather than reading
9449 the symbol table from the executable program. Using the '-mapped'
9450 option in a GDB `file' or `symbol-file' command has the same effect as
9451 starting GDB with the '-mapped' command-line option.
9453 You can cause GDB to read the entire symbol table immediately by using
9454 the '-readnow' option with any of the commands that load symbol table
9455 information (or on the GDB command line). This makes the command
9456 slower, but makes future operations faster.
9458 The -mapped and -readnow options are typically combined in order to
9459 build a `fred.syms' file that contains complete symbol information.
9460 A simple GDB invocation to do nothing but build a `.syms' file for future
9463 gdb -batch -nx -mapped -readnow programname
9465 The `.syms' file is specific to the host machine on which GDB is run.
9466 It holds an exact image of GDB's internal symbol table. It cannot be
9467 shared across multiple host platforms.
9469 * longjmp() handling
9471 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
9472 siglongjmp() without losing control. This feature has not yet been ported to
9473 all systems. It currently works on many 386 platforms, all MIPS-based
9474 platforms (SGI, DECstation, etc), and Sun3/4.
9478 Preliminary work has been put in to support the new Solaris OS from Sun. At
9479 this time, it can control and debug processes, but it is not capable of
9484 As always, many many bug fixes. The major areas were with g++, and mipsread.
9485 People using the MIPS-based platforms should experience fewer mysterious
9486 crashes and trashed symbol tables.
9488 *** Changes in GDB-4.4:
9490 * New machines supported (host and target)
9492 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
9494 BSD Reno on Vax vax-dec-bsd
9495 Ultrix on Vax vax-dec-ultrix
9497 * New machines supported (target)
9499 AMD 29000 embedded, using EBMON a29k-none-none
9503 GDB continues to improve its handling of C++. `References' work better.
9504 The demangler has also been improved, and now deals with symbols mangled as
9505 per the Annotated C++ Reference Guide.
9507 GDB also now handles `stabs' symbol information embedded in MIPS
9508 `ecoff' symbol tables. Since the ecoff format was not easily
9509 extensible to handle new languages such as C++, this appeared to be a
9510 good way to put C++ debugging info into MIPS binaries. This option
9511 will be supported in the GNU C compiler, version 2, when it is
9514 * New features for SVR4
9516 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
9517 shared libraries. Debugging dynamically linked programs should present
9518 only minor differences from debugging statically linked programs.
9520 The `info proc' command will print out information about any process
9521 on an SVR4 system (including the one you are debugging). At the moment,
9522 it prints the address mappings of the process.
9524 If you bring up GDB on another SVR4 system, please send mail to
9525 bug-gdb@prep.ai.mit.edu to let us know what changes were required (if any).
9527 * Better dynamic linking support in SunOS
9529 Reading symbols from shared libraries which contain debugging symbols
9530 now works properly. However, there remain issues such as automatic
9531 skipping of `transfer vector' code during function calls, which
9532 make it harder to debug code in a shared library, than to debug the
9533 same code linked statically.
9537 GDB is now using the latest `getopt' routines from the FSF. This
9538 version accepts the -- prefix for options with long names. GDB will
9539 continue to accept the old forms (-option and +option) as well.
9540 Various single letter abbreviations for options have been explicitly
9541 added to the option table so that they won't get overshadowed in the
9542 future by other options that begin with the same letter.
9546 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
9547 Many assorted bugs have been handled. Many more remain to be handled.
9548 See the various ChangeLog files (primarily in gdb and bfd) for details.
9551 *** Changes in GDB-4.3:
9553 * New machines supported (host and target)
9555 Amiga 3000 running Amix m68k-cbm-svr4 or amix
9556 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
9557 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
9559 * Almost SCO Unix support
9561 We had hoped to support:
9562 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
9563 (except for core file support), but we discovered very late in the release
9564 that it has problems with process groups that render gdb unusable. Sorry
9565 about that. I encourage people to fix it and post the fixes.
9567 * Preliminary ELF and DWARF support
9569 GDB can read ELF object files on System V Release 4, and can handle
9570 debugging records for C, in DWARF format, in ELF files. This support
9571 is preliminary. If you bring up GDB on another SVR4 system, please
9572 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
9577 GDB now uses the latest `readline' library. One user-visible change
9578 is that two tabs will list possible command completions, which previously
9579 required typing M-? (meta-question mark, or ESC ?).
9583 The `stepi' bug that many of you noticed has been squashed.
9584 Many bugs in C++ have been handled. Many more remain to be handled.
9585 See the various ChangeLog files (primarily in gdb and bfd) for details.
9587 * State of the MIPS world (in case you wondered):
9589 GDB can understand the symbol tables emitted by the compilers
9590 supplied by most vendors of MIPS-based machines, including DEC. These
9591 symbol tables are in a format that essentially nobody else uses.
9593 Some versions of gcc come with an assembler post-processor called
9594 mips-tfile. This program is required if you want to do source-level
9595 debugging of gcc-compiled programs. I believe FSF does not ship
9596 mips-tfile with gcc version 1, but it will eventually come with gcc
9599 Debugging of g++ output remains a problem. g++ version 1.xx does not
9600 really support it at all. (If you're lucky, you should be able to get
9601 line numbers and stack traces to work, but no parameters or local
9602 variables.) With some work it should be possible to improve the
9605 When gcc version 2 is released, you will have somewhat better luck.
9606 However, even then you will get confusing results for inheritance and
9609 We will eventually provide full debugging of g++ output on
9610 DECstations. This will probably involve some kind of stabs-in-ecoff
9611 encapulation, but the details have not been worked out yet.
9614 *** Changes in GDB-4.2:
9616 * Improved configuration
9618 Only one copy of `configure' exists now, and it is not self-modifying.
9619 Porting BFD is simpler.
9623 The `step' and `next' commands now only stop at the first instruction
9624 of a source line. This prevents the multiple stops that used to occur
9625 in switch statements, for-loops, etc. `Step' continues to stop if a
9626 function that has debugging information is called within the line.
9630 Lots of small bugs fixed. More remain.
9632 * New host supported (not target)
9634 Intel 386 PC clone running Mach i386-none-mach
9637 *** Changes in GDB-4.1:
9639 * Multiple source language support
9641 GDB now has internal scaffolding to handle several source languages.
9642 It determines the type of each source file from its filename extension,
9643 and will switch expression parsing and number formatting to match the
9644 language of the function in the currently selected stack frame.
9645 You can also specifically set the language to be used, with
9646 `set language c' or `set language modula-2'.
9650 GDB now has preliminary support for the GNU Modula-2 compiler,
9651 currently under development at the State University of New York at
9652 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
9653 continue through the fall of 1991 and into 1992.
9655 Other Modula-2 compilers are currently not supported, and attempting to
9656 debug programs compiled with them will likely result in an error as the
9657 symbol table is read. Feel free to work on it, though!
9659 There are hooks in GDB for strict type checking and range checking,
9660 in the `Modula-2 philosophy', but they do not currently work.
9664 GDB can now write to executable and core files (e.g. patch
9665 a variable's value). You must turn this switch on, specify
9666 the file ("exec foo" or "core foo"), *then* modify it, e.g.
9667 by assigning a new value to a variable. Modifications take
9670 * Automatic SunOS shared library reading
9672 When you run your program, GDB automatically determines where its
9673 shared libraries (if any) have been loaded, and reads their symbols.
9674 The `share' command is no longer needed. This also works when
9675 examining core files.
9679 You can specify the number of lines that the `list' command shows.
9682 * New machines supported (host and target)
9684 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
9685 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
9686 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
9688 * New hosts supported (not targets)
9690 IBM RT/PC: romp-ibm-aix or rtpc
9692 * New targets supported (not hosts)
9694 AMD 29000 embedded with COFF a29k-none-coff
9695 AMD 29000 embedded with a.out a29k-none-aout
9696 Ultracomputer remote kernel debug a29k-nyu-kern
9698 * New remote interfaces
9704 *** Changes in GDB-4.0:
9708 Wide output is wrapped at good places to make the output more readable.
9710 Gdb now supports cross-debugging from a host machine of one type to a
9711 target machine of another type. Communication with the target system
9712 is over serial lines. The ``target'' command handles connecting to the
9713 remote system; the ``load'' command will download a program into the
9714 remote system. Serial stubs for the m68k and i386 are provided. Gdb
9715 also supports debugging of realtime processes running under VxWorks,
9716 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
9717 stub on the target system.
9719 New CPUs supported include the AMD 29000 and Intel 960.
9721 GDB now reads object files and symbol tables via a ``binary file''
9722 library, which allows a single copy of GDB to debug programs of multiple
9723 object file types such as a.out and coff.
9725 There is now a GDB reference card in "doc/refcard.tex". (Make targets
9726 refcard.dvi and refcard.ps are available to format it).
9729 * Control-Variable user interface simplified
9731 All variables that control the operation of the debugger can be set
9732 by the ``set'' command, and displayed by the ``show'' command.
9734 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
9735 ``Show prompt'' produces the response:
9736 Gdb's prompt is new-gdb=>.
9738 What follows are the NEW set commands. The command ``help set'' will
9739 print a complete list of old and new set commands. ``help set FOO''
9740 will give a longer description of the variable FOO. ``show'' will show
9741 all of the variable descriptions and their current settings.
9743 confirm on/off: Enables warning questions for operations that are
9744 hard to recover from, e.g. rerunning the program while
9745 it is already running. Default is ON.
9747 editing on/off: Enables EMACS style command line editing
9748 of input. Previous lines can be recalled with
9749 control-P, the current line can be edited with control-B,
9750 you can search for commands with control-R, etc.
9753 history filename NAME: NAME is where the gdb command history
9754 will be stored. The default is .gdb_history,
9755 or the value of the environment variable
9758 history size N: The size, in commands, of the command history. The
9759 default is 256, or the value of the environment variable
9762 history save on/off: If this value is set to ON, the history file will
9763 be saved after exiting gdb. If set to OFF, the
9764 file will not be saved. The default is OFF.
9766 history expansion on/off: If this value is set to ON, then csh-like
9767 history expansion will be performed on
9768 command line input. The default is OFF.
9770 radix N: Sets the default radix for input and output. It can be set
9771 to 8, 10, or 16. Note that the argument to "radix" is interpreted
9772 in the current radix, so "set radix 10" is always a no-op.
9774 height N: This integer value is the number of lines on a page. Default
9775 is 24, the current `stty rows'' setting, or the ``li#''
9776 setting from the termcap entry matching the environment
9779 width N: This integer value is the number of characters on a line.
9780 Default is 80, the current `stty cols'' setting, or the ``co#''
9781 setting from the termcap entry matching the environment
9784 Note: ``set screensize'' is obsolete. Use ``set height'' and
9785 ``set width'' instead.
9787 print address on/off: Print memory addresses in various command displays,
9788 such as stack traces and structure values. Gdb looks
9789 more ``symbolic'' if you turn this off; it looks more
9790 ``machine level'' with it on. Default is ON.
9792 print array on/off: Prettyprint arrays. New convenient format! Default
9795 print demangle on/off: Print C++ symbols in "source" form if on,
9798 print asm-demangle on/off: Same, for assembler level printouts
9801 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
9804 * Support for Epoch Environment.
9806 The epoch environment is a version of Emacs v18 with windowing. One
9807 new command, ``inspect'', is identical to ``print'', except that if you
9808 are running in the epoch environment, the value is printed in its own
9812 * Support for Shared Libraries
9814 GDB can now debug programs and core files that use SunOS shared libraries.
9815 Symbols from a shared library cannot be referenced
9816 before the shared library has been linked with the program (this
9817 happens after you type ``run'' and before the function main() is entered).
9818 At any time after this linking (including when examining core files
9819 from dynamically linked programs), gdb reads the symbols from each
9820 shared library when you type the ``sharedlibrary'' command.
9821 It can be abbreviated ``share''.
9823 sharedlibrary REGEXP: Load shared object library symbols for files
9824 matching a unix regular expression. No argument
9825 indicates to load symbols for all shared libraries.
9827 info sharedlibrary: Status of loaded shared libraries.
9832 A watchpoint stops execution of a program whenever the value of an
9833 expression changes. Checking for this slows down execution
9834 tremendously whenever you are in the scope of the expression, but is
9835 quite useful for catching tough ``bit-spreader'' or pointer misuse
9836 problems. Some machines such as the 386 have hardware for doing this
9837 more quickly, and future versions of gdb will use this hardware.
9839 watch EXP: Set a watchpoint (breakpoint) for an expression.
9841 info watchpoints: Information about your watchpoints.
9843 delete N: Deletes watchpoint number N (same as breakpoints).
9844 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
9845 enable N: Re-enables watchpoint number N (same as breakpoints).
9848 * C++ multiple inheritance
9850 When used with a GCC version 2 compiler, GDB supports multiple inheritance
9853 * C++ exception handling
9855 Gdb now supports limited C++ exception handling. Besides the existing
9856 ability to breakpoint on an exception handler, gdb can breakpoint on
9857 the raising of an exception (before the stack is peeled back to the
9860 catch FOO: If there is a FOO exception handler in the dynamic scope,
9861 set a breakpoint to catch exceptions which may be raised there.
9862 Multiple exceptions (``catch foo bar baz'') may be caught.
9864 info catch: Lists all exceptions which may be caught in the
9865 current stack frame.
9868 * Minor command changes
9870 The command ``call func (arg, arg, ...)'' now acts like the print
9871 command, except it does not print or save a value if the function's result
9872 is void. This is similar to dbx usage.
9874 The ``up'' and ``down'' commands now always print the frame they end up
9875 at; ``up-silently'' and `down-silently'' can be used in scripts to change
9876 frames without printing.
9878 * New directory command
9880 'dir' now adds directories to the FRONT of the source search path.
9881 The path starts off empty. Source files that contain debug information
9882 about the directory in which they were compiled can be found even
9883 with an empty path; Sun CC and GCC include this information. If GDB can't
9884 find your source file in the current directory, type "dir .".
9886 * Configuring GDB for compilation
9888 For normal use, type ``./configure host''. See README or gdb.texinfo
9891 GDB now handles cross debugging. If you are remotely debugging between
9892 two different machines, type ``./configure host -target=targ''.
9893 Host is the machine where GDB will run; targ is the machine
9894 where the program that you are debugging will run.