1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 13
6 * GDB now has some support for integer types larger than 64 bits.
8 * Removed targets and native configurations
10 GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
11 AIX version is now AIX 7.1.
13 * Multi-target feature configuration
15 GDB now supports the individual configuration of remote targets' feature
16 sets. Based on the current selection of a target, the commands 'set remote
17 <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
18 configure a target's feature packet and to display its configuration,
21 The individual packet sizes can be configured and shown using the commands
22 ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
23 ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
24 ** 'show remote memory-read-packet-size'
25 ** 'show remote memory-write-packet-size'.
27 The configuration of the packet itself, as well as the size of a memory-read
28 or memory-write packet applies to the currently selected target (if
29 available). If no target is selected, it applies to future remote
30 connections. Similarly, the show commands print the configuration of the
31 currently selected target. If no remote target is selected, the default
32 configuration for future connections is shown.
34 * MI version 1 has been removed.
36 * GDB has initial built-in support for the Debugger Adapter Protocol.
37 This support requires that GDB be built with Python scripting
40 * For the break command, multiple uses of the 'thread' or 'task'
41 keywords will now give an error instead of just using the thread or
42 task id from the last instance of the keyword. E.g.:
43 break foo thread 1 thread 2
44 will now give an error rather than using 'thread 2'.
46 * For the watch command, multiple uses of the 'task' keyword will now
47 give an error instead of just using the task id from the last
48 instance of the keyword. E.g.:
49 watch my_var task 1 task 2
50 will now give an error rather than using 'task 2'. The 'thread'
51 keyword already gave an error when used multiple times with the
52 watch command, this remains unchanged.
54 * The 'set print elements' setting now helps when printing large arrays.
55 If an array would otherwise exceed max-value-size, but 'print elements'
56 is set such that the size of elements to print is less than or equal
57 to 'max-value-size', GDB will now still print the array, however only
58 'max-value-size' worth of data will be added into the value history.
60 * For both the break and watch commands, it is now invalid to use both
61 the 'thread' and 'task' keywords within the same command. For
62 example the following commnds will now give an error:
63 break foo thread 1 task 1
64 watch var thread 2 task 3
68 maintenance print record-instruction [ N ]
69 Print the recorded information for a given instruction. If N is not given
70 prints how GDB would undo the last instruction executed. If N is negative,
71 prints how GDB would undo the N-th previous instruction, and if N is
72 positive, it prints how GDB will redo the N-th following instruction.
74 maintenance info frame-unwinders
75 List the frame unwinders currently in effect, starting with the highest
78 maintenance wait-for-index-cache
79 Wait until all pending writes to the index cache have completed.
81 set always-read-ctf on|off
83 When off, CTF is only read if DWARF is not present. When on, CTF is
84 read regardless of whether DWARF is present. Off by default.
86 * New convenience function "$_shell", to execute a shell command and
87 return the result. This lets you run shell commands in expressions.
90 (gdb) p $_shell("true")
92 (gdb) p $_shell("false")
94 (gdb) break func if $_shell("some command") == 0
98 ** mi now reports 'no-history' as a stop reason when hitting the end of the
99 reverse execution history.
101 ** When creating a thread-specific breakpoint using the '-p' option,
102 the -break-insert command would report the 'thread' field twice in
103 the reply. The content of both fields was always identical. This
104 has now been fixed; the 'thread' field will be reported just once
105 for thread-specific breakpoints, or not at all for breakpoints
106 without a thread restriction. The same is also true for the 'task'
107 field of an Ada task-specific breakpoint.
111 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
113 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
114 now be of type 'str' otherwise a TypeError will be raised.
116 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
117 values of type 'bool'. Changing this attribute will now
118 invalidate GDB's frame-cache, which means GDB will need to
119 rebuild its frame-cache when next required - either with, or
120 without the particular unwinder, depending on how 'enabled' was
123 ** New methods added to the gdb.PendingFrame class. These methods
124 have the same behaviour as the corresponding methods on
125 gdb.Frame. The new methods are:
127 - gdb.PendingFrame.name: Return the name for the frame's
129 - gdb.PendingFrame.is_valid: Return True if the pending frame
131 - gdb.PendingFrame.pc: Return the $pc register value for this
133 - gdb.PendingFrame.language: Return a string containing the
134 language for this frame, or None.
135 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
136 object for the current location within the pending frame, or
138 - gdb.PendingFrame.block: Return a gdb.Block for the current
139 pending frame, or None.
140 - gdb.PendingFrame.function: Return a gdb.Symbol for the
141 current pending frame, or None.
143 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
144 now use either an integer or a gdb.Value object for each of its
145 'sp', 'pc', and 'special' attributes.
147 ** A new class gdb.unwinder.FrameId has been added. Instances of
148 this class are constructed with 'sp' (stack-pointer) and 'pc'
149 (program-counter) values, and can be used as the frame-id when
150 calling gdb.PendingFrame.create_unwind_info.
152 *** Changes in GDB 13
154 * MI version 1 is deprecated, and will be removed in GDB 14.
156 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
157 reading memory tag data for AArch64 MTE from core files generated by
158 the gcore command or the Linux kernel.
160 When a process uses memory-mapped pages protected by memory tags (for
161 example, AArch64 MTE), this additional information will be recorded in
162 the core file in the event of a crash or if GDB generates a core file
163 from the current process state. GDB will show this additional information
164 automatically, or through one of the memory-tag subcommands.
166 * "info breakpoints" now displays enabled breakpoint locations of
167 disabled breakpoints as in the "y-" state. For example:
169 (gdb) info breakpoints
170 Num Type Disp Enb Address What
171 1 breakpoint keep n <MULTIPLE>
172 1.1 y- 0x00000000000011b6 in ...
173 1.2 y- 0x00000000000011c2 in ...
174 1.3 n 0x00000000000011ce in ...
176 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
177 aarch64 architectures.
179 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
181 * Remove support for building against Python 2, it is now only possible to
182 build GDB against Python 3.
184 * DBX mode has been removed.
186 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
187 emit to indicate where a breakpoint should be placed to break in a function
190 * Completion now also offers "NUMBER" for "set" commands that accept
191 a numeric argument and the "unlimited" keyword. For example:
193 (gdb) set width <TAB>
198 (gdb) complete set width
202 * Disassembler styling using libopcodes. GDB now supports
203 disassembler styling using libopcodes. This is only available for
204 some targets (currently x86 and RISC-V). For unsupported targets
205 Python Pygments is still used. For supported targets, libopcodes
206 styling is used by default.
208 * The Windows native target now supports target async.
210 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
212 * The format of 'disassemble /r' and 'record instruction-history /r'
213 has changed. The instruction bytes could now be grouped together,
214 and displayed in the endianness of the instruction. This is the
215 same layout as used by GNU objdump when disassembling.
217 There is now 'disassemble /b' and 'record instruction-history /b'
218 which will always display the instructions bytes one at a time in
219 memory order, that is, the byte at the lowest address first.
221 For both /r and /b GDB is now better at using whitespace in order to
222 align the disassembled instruction text.
224 * The TUI no longer styles the source and assembly code highlighted by
225 the current position indicator by default. You can however
226 re-enable styling using the new "set style tui-current-position"
229 * New convenience variable $_inferior_thread_count contains the number
230 of live threads in the current inferior.
232 * When a breakpoint with multiple code locations is hit, GDB now prints
233 the code location using the syntax <breakpoint_number>.<location_number>
235 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
237 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
238 and $_hit_locno to the hit breakpoint number and code location number.
239 This allows to disable the last hit breakpoint using
240 (gdb) disable $_hit_bpnum
241 or disable only the specific breakpoint code location using
242 (gdb) disable $_hit_bpnum.$_hit_locno
243 These commands can be used inside the command list of a breakpoint to
244 automatically disable the just encountered breakpoint (or the just
245 encountered specific breakpoint code location).
246 When a breakpoint has only one location, $_hit_locno is set to 1 so that
247 (gdb) disable $_hit_bpnum.$_hit_locno
249 (gdb) disable $_hit_bpnum
250 are both disabling the breakpoint.
254 maintenance set ignore-prologue-end-flag on|off
255 maintenance show ignore-prologue-end-flag
256 This setting, which is off by default, controls whether GDB ignores the
257 PROLOGUE-END flag from the line-table when skipping prologue. This can be
258 used to force GDB to use prologue analyzers if the line-table is constructed
259 from erroneous debug information.
261 set print nibbles [on|off]
263 This controls whether the 'print/t' command will display binary values
264 in groups of four bits, known as "nibbles". The default is 'off'.
266 maintenance set libopcodes-styling on|off
267 maintenance show libopcodes-styling
268 These can be used to force off libopcodes based styling, the Python
269 Pygments styling will then be used instead.
271 set style disassembler comment
272 show style disassembler comment
273 set style disassembler immediate
274 show style disassembler immediate
275 set style disassembler mnemonic
276 show style disassembler mnemonic
277 set style disassembler register
278 show style disassembler register
279 set style disassembler address
280 show style disassembler address
281 set style disassembler symbol
282 show style disassembler symbol
283 For targets that support libopcodes based styling, these settings
284 control how various aspects of the disassembler output are styled.
285 The 'disassembler address' and 'disassembler symbol' styles are
286 aliases for the 'address' and 'function' styles respectively.
288 maintenance print frame-id [ LEVEL ]
289 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
290 not given, then print the frame-id for the currently selected frame.
292 set debug infcall on|off
294 Print additional debug messages about inferior function calls.
296 set debug solib on|off
298 Print additional debug messages about shared library handling.
300 set style tui-current-position [on|off]
301 Whether to style the source and assembly code highlighted by the
302 TUI's current position indicator. The default is off.
304 set print characters LIMIT
305 show print characters
306 This new setting is like 'set print elements', but controls how many
307 characters of a string are printed. This functionality used to be
308 covered by 'set print elements', but it can be controlled separately
309 now. LIMIT can be set to a numerical value to request that particular
310 character count, to 'unlimited' to print all characters of a string,
311 or to 'elements', which is also the default, to follow the setting of
312 'set print elements' as it used to be.
314 print -characters LIMIT
315 This new option to the 'print' command has the same effect as a temporary
316 use of 'set print characters'.
320 document user-defined
321 It is now possible to document user-defined aliases.
322 When a user-defined alias is documented, the help and apropos commands
323 use the provided documentation instead of the documentation of the
325 Documenting a user-defined alias is particularly useful when the alias
326 is a set of nested 'with' commands to avoid showing the help of
327 the with command for an alias that will in fact launch the
328 last command given in the nested commands.
330 maintenance info line-table
331 Add a PROLOGUE-END column to the output which indicates that an
332 entry corresponds to an address where a breakpoint should be placed
333 to be at the first instruction past a function's prologue.
337 set debug aix-solib on|off
339 set debug solib-frv on|off
341 Removed in favor of "set/show debug solib".
343 maintenance info program-spaces
344 This command now includes a 'Core File' column which indicates the
345 name of the core file associated with each program space.
349 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
351 GNU/Linux/CSKY (gdbserver) csky*-*linux*
357 ** The async record stating the stopped reason 'breakpoint-hit' now
358 contains an optional field locno giving the code location number
359 when the breakpoint has multiple code locations.
363 ** GDB will now reformat the doc string for gdb.Command and
364 gdb.Parameter sub-classes to remove unnecessary leading
365 whitespace from each line before using the string as the help
368 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
369 that formats ADDRESS as 'address <symbol+offset>', where symbol is
370 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
371 This is the same format that GDB uses when printing address, symbol,
372 and offset information from the disassembler.
374 ** New function gdb.current_language that returns the name of the
375 current language. Unlike gdb.parameter('language'), this will
378 ** New method gdb.Frame.language that returns the name of the
381 ** New Python API for wrapping GDB's disassembler:
383 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
384 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
385 ARCH is either None or a string containing a bfd architecture
386 name. DISASSEMBLER is registered as a disassembler for
387 architecture ARCH, or for all architectures if ARCH is None.
388 The previous disassembler registered for ARCH is returned, this
389 can be None if no previous disassembler was registered.
391 - gdb.disassembler.Disassembler is the class from which all
392 disassemblers should inherit. Its constructor takes a string,
393 a name for the disassembler, which is currently only used in
394 some debug output. Sub-classes should override the __call__
395 method to perform disassembly, invoking __call__ on this base
396 class will raise an exception.
398 - gdb.disassembler.DisassembleInfo is the class used to describe
399 a single disassembly request from GDB. An instance of this
400 class is passed to the __call__ method of
401 gdb.disassembler.Disassembler and has the following read-only
402 attributes: 'address', and 'architecture', as well as the
403 following method: 'read_memory'.
405 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
406 calls GDB's builtin disassembler on INFO, which is a
407 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
408 optional, its default value is None. If MEMORY_SOURCE is not
409 None then it must be an object that has a 'read_memory' method.
411 - gdb.disassembler.DisassemblerResult is a class that can be used
412 to wrap the result of a call to a Disassembler. It has
413 read-only attributes 'length' and 'string'.
415 ** gdb.Objfile now has an attribute named "is_file". This is True
416 if the objfile comes from a file, and False otherwise.
418 ** New function gdb.print_options that returns a dictionary of the
419 prevailing print options, in the form accepted by
420 gdb.Value.format_string.
422 ** gdb.Value.format_string now uses the format provided by 'print',
423 if it is called during a 'print' or other similar operation.
425 ** gdb.Value.format_string now accepts the 'summary' keyword. This
426 can be used to request a shorter representation of a value, the
427 way that 'set print frame-arguments scalars' does.
429 ** New Python type gdb.BreakpointLocation.
430 The new attribute 'locations' of gdb.Breakpoint returns a list of
431 gdb.BreakpointLocation objects specifying the locations where the
432 breakpoint is inserted into the debuggee.
434 ** The gdb.register_window_type method now restricts the set of
435 acceptable window names. The first character of a window's name
436 must start with a character in the set [a-zA-Z], every subsequent
437 character of a window's name must be in the set [-_.a-zA-Z0-9].
439 * New features in the GDB remote stub, GDBserver
441 ** GDBserver is now supported on LoongArch GNU/Linux.
443 ** GDBserver is now supported on CSKY GNU/Linux.
445 * LoongArch floating-point support
447 GDB now supports floating-point on LoongArch GNU/Linux.
449 * AMD GPU ROCm debugging support
451 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
454 *** Changes in GDB 12
456 * DBX mode is deprecated, and will be removed in GDB 13
458 * GDB 12 is the last release of GDB that will support building against
459 Python 2. From GDB 13, it will only be possible to build GDB itself
460 with Python 3 support.
462 * The disable-randomization setting now works on Windows.
464 * Improved C++ template support
466 GDB now treats functions/types involving C++ templates like it does function
467 overloads. Users may omit parameter lists to set breakpoints on families of
468 template functions, including types/functions composed of multiple template types:
470 (gdb) break template_func(template_1, int)
472 The above will set breakpoints at every function `template_func' where
473 the first function parameter is any template type named `template_1' and
474 the second function parameter is `int'.
476 TAB completion also gains similar improvements.
478 * The FreeBSD native target now supports async mode.
484 Enable or disable multithreaded symbol loading. This is enabled
485 by default, but passing --disable-threading or --enable-threading=no
486 to configure will disable it.
488 Disabling this can cause a performance penalty when there are a lot of
489 symbols to load, but is useful for debugging purposes.
493 maint set backtrace-on-fatal-signal on|off
494 maint show backtrace-on-fatal-signal
495 This setting is 'on' by default. When 'on' GDB will print a limited
496 backtrace to stderr in the situation where GDB terminates with a
497 fatal signal. This only supported on some platforms where the
498 backtrace and backtrace_symbols_fd functions are available.
500 set source open on|off
502 This setting, which is on by default, controls whether GDB will try
503 to open source code files. Switching this off will stop GDB trying
504 to open and read source code files, which can be useful if the files
505 are located over a slow network connection.
509 These are now deprecated aliases for "set max-value-size" and
510 "show max-value-size".
512 task apply [all | TASK-IDS...] [FLAG]... COMMAND
513 Like "thread apply", but applies COMMAND to Ada tasks.
516 Watchpoints can now be restricted to a specific Ada task.
518 maint set internal-error backtrace on|off
519 maint show internal-error backtrace
520 maint set internal-warning backtrace on|off
521 maint show internal-warning backtrace
522 GDB can now print a backtrace of itself when it encounters either an
523 internal-error, or an internal-warning. This is on by default for
524 internal-error and off by default for internal-warning.
527 Deprecated and replaced by "set logging enabled on|off".
529 set logging enabled on|off
531 These commands set or show whether logging is enabled or disabled.
534 You can now exit GDB by using the new command "exit", in addition to
535 the existing "quit" command.
537 set debug threads on|off
539 Print additional debug messages about thread creation and deletion.
541 set debug linux-nat on|off
543 These new commands replaced the old 'set debug lin-lwp' and 'show
544 debug lin-lwp' respectively. Turning this setting on prints debug
545 messages relating to GDB's handling of native Linux inferiors.
547 maint flush source-cache
548 Flush the contents of the source code cache.
550 maint set gnu-source-highlight enabled on|off
551 maint show gnu-source-highlight enabled
552 Whether GDB should use the GNU Source Highlight library for adding
553 styling to source code. When off, the library will not be used, even
554 when available. When GNU Source Highlight isn't used, or can't add
555 styling to a particular source file, then the Python Pygments
556 library will be used instead.
558 set suppress-cli-notifications (on|off)
559 show suppress-cli-notifications
560 This controls whether printing the notifications is suppressed for CLI.
561 CLI notifications occur when you change the selected context
562 (i.e., the current inferior, thread and/or the frame), or when
563 the program being debugged stops (e.g., because of hitting a
564 breakpoint, completing source-stepping, an interrupt, etc.).
566 set style disassembler enabled on|off
567 show style disassembler enabled
568 If GDB is compiled with Python support, and the Python Pygments
569 package is available, then, when this setting is on, disassembler
570 output will have styling applied.
572 set ada source-charset
573 show ada source-charset
574 Set the character set encoding that is assumed for Ada symbols. Valid
575 values for this follow the values that can be passed to the GNAT
576 compiler via the '-gnati' option. The default is ISO-8859-1.
582 These are the new names for the old 'layout', 'focus', 'refresh',
583 and 'winheight' tui commands respectively. The old names still
584 exist as aliases to these new commands.
588 The new command 'tui window width', and the alias 'winwidth' allow
589 the width of a tui window to be adjusted when windows are laid out
594 Control the display of debug output about GDB's tui.
599 Printing of floating-point values with base-modifying formats like
600 /x has been changed to display the underlying bytes of the value in
601 the desired base. This was GDB's documented behavior, but was never
602 implemented correctly.
605 This command can now print a reply, if the reply includes
606 non-printable characters. Any non-printable characters are printed
607 as escaped hex, e.g. \x?? where '??' is replaces with the value of
608 the non-printable character.
611 The clone-inferior command now ensures that the TTY, CMD and ARGS
612 settings are copied from the original inferior to the new one.
613 All modifications to the environment variables done using the 'set
614 environment' or 'unset environment' commands are also copied to the new
617 set debug lin-lwp on|off
619 These commands have been removed from GDB. The new command 'set
620 debug linux-nat' and 'show debug linux-nat' should be used
624 This command now includes information about the width of the tui
625 windows in its output.
631 These commands are now aliases for the 'tui layout', 'tui focus',
632 'tui refresh', and 'tui window height' commands respectively.
634 * GDB's Ada parser now supports an extension for specifying the exact
635 byte contents of a floating-point literal. This can be useful for
636 setting floating-point registers to a precise value without loss of
637 precision. The syntax is an extension of the based literal syntax.
638 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
639 of the floating-point type, and the "f" is the marker for floating
644 ** The '-add-inferior' with no option flags now inherits the
645 connection of the current inferior, this restores the behaviour of
646 GDB as it was prior to GDB 10.
648 ** The '-add-inferior' command now accepts a '--no-connection'
649 option, which causes the new inferior to start without a
652 ** The default version of the MI interpreter is now 4 (-i=mi4).
654 ** The "script" field in breakpoint output (which is syntactically
655 incorrect in MI 3 and below) has changed in MI 4 to become a list.
656 This affects the following commands and events:
660 - =breakpoint-created
661 - =breakpoint-modified
663 The -fix-breakpoint-script-output command can be used to enable
664 this behavior with previous MI versions.
668 GNU/Linux/LoongArch loongarch*-*-linux*
676 ** New function gdb.add_history(), which takes a gdb.Value object
677 and adds the value it represents to GDB's history list. An
678 integer, the index of the new item in the history list, is
681 ** New function gdb.history_count(), which returns the number of
682 values in GDB's value history.
684 ** New gdb.events.gdb_exiting event. This event is called with a
685 gdb.GdbExitingEvent object which has the read-only attribute
686 'exit_code', which contains the value of the GDB exit code. This
687 event is triggered once GDB decides it is going to exit, but
688 before GDB starts to clean up its internal state.
690 ** New function gdb.architecture_names(), which returns a list
691 containing all of the possible Architecture.name() values. Each
694 ** New function gdb.Architecture.integer_type(), which returns an
695 integer type given a size and a signed-ness.
697 ** New gdb.TargetConnection object type that represents a connection
698 (as displayed by the 'info connections' command). A sub-class,
699 gdb.RemoteTargetConnection, is used to represent 'remote' and
700 'extended-remote' connections.
702 ** The gdb.Inferior type now has a 'connection' property which is an
703 instance of gdb.TargetConnection, the connection used by this
704 inferior. This can be None if the inferior has no connection.
706 ** New 'gdb.events.connection_removed' event registry, which emits a
707 'gdb.ConnectionEvent' when a connection is removed from GDB.
708 This event has a 'connection' property, a gdb.TargetConnection
709 object for the connection being removed.
711 ** New gdb.connections() function that returns a list of all
712 currently active connections.
714 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
715 is equivalent to the existing 'maint packet' CLI command; it
716 allows a user specified packet to be sent to the remote target.
718 ** New function gdb.host_charset(), returns a string, which is the
719 name of the current host charset.
721 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
724 ** New gdb.with_parameter(NAME, VALUE). This returns a context
725 manager that temporarily sets the gdb parameter NAME to VALUE,
726 then resets it when the context is exited.
728 ** The gdb.Value.format_string method now takes a 'styling'
729 argument, which is a boolean. When true, the returned string can
730 include escape sequences to apply styling. The styling will only
731 be present if styling is otherwise turned on in GDB (see 'help
732 set styling'). When false, which is the default if the argument
733 is not given, then no styling is applied to the returned string.
735 ** New read-only attribute gdb.InferiorThread.details, which is
736 either a string, containing additional, target specific thread
737 state information, or None, if there is no such additional
740 ** New read-only attribute gdb.Type.is_scalar, which is True for
741 scalar types, and False for all other types.
743 ** New read-only attribute gdb.Type.is_signed. This attribute
744 should only be read when Type.is_scalar is True, and will be True
745 for signed types, and False for all other types. Attempting to
746 read this attribute for non-scalar types will raise a ValueError.
748 ** It is now possible to add GDB/MI commands implemented in Python.
750 * New features in the GDB remote stub, GDBserver
752 ** GDBserver is now supported on OpenRISC GNU/Linux.
754 * New native configurations
756 GNU/Linux/OpenRISC or1k*-*-linux*
758 *** Changes in GDB 11
760 * The 'set disassembler-options' command now supports specifying options
763 * GDB now supports general memory tagging functionality if the underlying
764 architecture supports the proper primitives and hooks. Currently this is
765 enabled only for AArch64 MTE.
769 - Additional information when the inferior crashes with a SIGSEGV caused by
770 a memory tag violation.
772 - A new modifier 'm' for the "x" command, which displays allocation tags for a
773 particular memory range.
775 - Display of memory tag mismatches by "print", for addresses and
776 pointers, if memory tagging is supported by the architecture.
778 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
783 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
785 The MI -break-insert and -dprintf-insert commands now support a
786 new "--qualified" option that makes GDB interpret a specified
787 function name as a complete fully-qualified name. This is the
788 equivalent of the CLI's "break -qualified" and "dprintf
791 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
793 The MI -break-insert and -dprintf-insert commands now support a
794 '--force-condition' flag to forcibly define a condition even when
795 the condition is invalid at all locations of the breakpoint. This
796 is equivalent to the '-force-condition' flag of the CLI's "break"
799 ** '-break-condition --force'
801 The MI -break-condition command now supports a '--force' flag to
802 forcibly define a condition even when the condition is invalid at
803 all locations of the selected breakpoint. This is equivalent to
804 the '-force' flag of the CLI's "cond" command.
806 ** '-file-list-exec-source-files [--group-by-objfile]
807 [--basename | --dirname]
810 The existing -file-list-exec-source-files command now takes an
811 optional REGEXP which is used to filter the source files that are
812 included in the results.
814 By default REGEXP is matched against the full filename of the
815 source file. When one of --basename or --dirname is given then
816 REGEXP is only matched against the specified part of the full
819 When the optional --group-by-objfile flag is used the output
820 format is changed, the results are now a list of object files
821 (executable and libraries) with the source files that are
822 associated with each object file.
824 The results from -file-list-exec-source-files now include a
825 'debug-fully-read' field which takes the value 'true' or 'false'.
826 A 'true' value indicates the source file is from a compilation
827 unit that has had its debug information fully read in by GDB, a
828 value of 'false' indicates GDB has only performed a partial scan
829 of the debug information so far.
831 * GDB now supports core file debugging for x86_64 Cygwin programs.
833 * GDB will now look for the .gdbinit file in a config directory before
834 looking for ~/.gdbinit. The file is searched for in the following
835 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
836 $HOME/.gdbinit. On Apple hosts the search order is instead:
837 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
839 * GDB now supports fixed point types which are described in DWARF
840 as base types with a fixed-point encoding. Additionally, support
841 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
844 For Ada, this allows support for fixed point types without requiring
845 the use of the GNAT encoding (based on information added to the type's
846 name following a GNAT-specific format).
848 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
849 or ~/.gdbearlyinit if these files are present. These files are
850 processed earlier than any of the other initialization files and
851 can affect parts of GDB's startup that previously had already been
852 completed before the initialization files were read, for example
853 styling of the initial GDB greeting.
855 * GDB now has two new options "--early-init-command" and
856 "--early-init-eval-command" with corresponding short options "-eix"
857 and "-eiex" that allow options (that would normally appear in a
858 gdbearlyinit file) to be passed on the command line.
860 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
861 now understood by GDB, and can be used to describe the vector
862 registers of a target. The precise requirements of this register
863 feature are documented in the GDB manual.
865 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
866 supported by GDB and describes a new VPR register from the ARM MVE
867 (Helium) extension. See the GDB manual for more information.
871 ** TUI windows now support mouse actions. The mouse wheel scrolls
872 the appropriate window.
874 ** Key combinations that do not have a specific action on the
875 focused window are passed to GDB. For example, you now can use
876 Ctrl-Left/Ctrl-Right to move between words in the command window
877 regardless of which window is in focus. Previously you would
878 need to focus on the command window for such key combinations to
884 show debug event-loop
885 Control the display of debug output about GDB's event loop.
887 set print memory-tag-violations
888 show print memory-tag-violations
889 Control whether to display additional information about memory tag violations
890 when printing pointers and addresses. Architecture support for memory
891 tagging is required for this option to have an effect.
893 maintenance flush symbol-cache
894 maintenance flush register-cache
895 These new commands are equivalent to the already existing commands
896 'maintenance flush-symbol-cache' and 'flushregs' respectively.
898 maintenance flush dcache
899 A new command to flush the dcache.
901 maintenance info target-sections
902 Print GDB's internal target sections table.
905 Print the JIT code objects in the inferior known to GDB.
907 memory-tag show-logical-tag POINTER
908 Print the logical tag for POINTER.
909 memory-tag with-logical-tag POINTER TAG
910 Print POINTER with logical tag TAG.
911 memory-tag show-allocation-tag ADDRESS
912 Print the allocation tag for ADDRESS.
913 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
914 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
915 memory-tag check POINTER
916 Validate that POINTER's logical tag matches the allocation tag.
918 set startup-quietly on|off
920 When 'on', this causes GDB to act as if "-silent" were passed on the
921 command line. This command needs to be added to an early
922 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
925 set print type hex on|off
927 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
928 and offsets of struct members. When 'off', decimal notation is used.
930 set python ignore-environment on|off
931 show python ignore-environment
932 When 'on', this causes GDB's builtin Python to ignore any
933 environment variables that would otherwise affect how Python
934 behaves. This command needs to be added to an early initialization
935 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
937 set python dont-write-bytecode auto|on|off
938 show python dont-write-bytecode
939 When 'on', this causes GDB's builtin Python to not write any
940 byte-code (.pyc files) to disk. This command needs to be added to
941 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
942 order to affect GDB. When 'off' byte-code will always be written.
943 When set to 'auto' (the default) Python will check the
944 PYTHONDONTWRITEBYTECODE environment variable.
948 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
949 [-force-condition] [if CONDITION]
950 This command would previously refuse setting a breakpoint if the
951 CONDITION expression is invalid at a location. It now accepts and
952 defines the breakpoint if there is at least one location at which
953 the CONDITION is valid. The locations for which the CONDITION is
954 invalid, are automatically disabled. If CONDITION is invalid at all
955 of the locations, setting the breakpoint is still rejected. However,
956 the '-force-condition' flag can be used in this case for forcing GDB to
957 define the breakpoint, making all the current locations automatically
958 disabled. This may be useful if the user knows the condition will
959 become meaningful at a future location, e.g. due to a shared library
962 condition [-force] N COND
963 The behavior of this command is changed the same way for the 'break'
964 command as explained above. The '-force' flag can be used to force
965 GDB into defining the condition even when COND is invalid for all the
966 current locations of breakpoint N.
969 maintenance flush-symbol-cache
970 These commands are deprecated in favor of the new commands
971 'maintenance flush register-cache' and 'maintenance flush
972 symbol-cache' respectively.
974 set style version foreground COLOR
975 set style version background COLOR
976 set style version intensity VALUE
977 Control the styling of GDB's version number text.
980 When the ID parameter is omitted, then this command prints information
981 about the current inferior. When the ID parameter is present, the
982 behavior of the command is unchanged and have the inferior ID become
983 the current inferior.
985 maintenance info sections
986 The ALLOBJ keyword has been replaced with an -all-objects command
987 line flag. It is now possible to filter which sections are printed
988 even when -all-objects is passed.
990 ptype[/FLAGS] TYPE | EXPRESSION
991 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
992 notation is used when printing sizes and offsets of struct members.
993 When '/d' is set, decimal notation is used when printing sizes and
994 offsets of struct members. Default behavior is given by 'show print
998 The info sources command output has been restructured. The results
999 are now based around a list of objfiles (executable and libraries),
1000 and for each objfile the source files that are part of that objfile
1003 * Removed targets and native configurations
1005 ARM Symbian arm*-*-symbianelf*
1007 * New remote packets
1010 Request the remote to send allocation tags for a particular memory range.
1012 Request the remote to store the specified allocation tags to the requested
1017 ** Improved support for rvalue reference values:
1018 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1019 value-referenced-value procedure now handles rvalue reference
1022 ** New procedures for obtaining value variants:
1023 value-reference-value, value-rvalue-reference-value and
1026 ** Temporary breakpoints can now be created with make-breakpoint and
1027 tested for using breakpoint-temporary?.
1031 ** Inferior objects now contain a read-only 'connection_num' attribute that
1032 gives the connection number as seen in 'info connections' and
1035 ** New method gdb.Frame.level() which returns the stack level of the
1038 ** New method gdb.PendingFrame.level() which returns the stack level
1039 of the frame object.
1041 ** When hitting a catchpoint, the Python API will now emit a
1042 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1043 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1045 ** Python TUI windows can now receive mouse click events. If the
1046 Window object implements the click method, it is called for each
1047 mouse click event in this window.
1049 *** Changes in GDB 10
1051 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1052 and "org.gnu.gdb.arc.aux". The old names are still supported but
1053 must be considered obsolete. They will be deprecated after some
1056 * Help and apropos commands will now show the documentation of a
1057 command only once, even if that command has one or more aliases.
1058 These commands now show the command name, then all of its aliases,
1059 and finally the description of the command.
1061 * 'help aliases' now shows only the user defined aliases. GDB predefined
1062 aliases are shown together with their aliased command.
1064 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1065 debugging information as well as source code.
1067 When built with debuginfod, GDB can automatically query debuginfod
1068 servers for the separate debug files and source code of the executable
1071 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1072 requires libdebuginfod, the debuginfod client library).
1074 debuginfod is distributed with elfutils, starting with version 0.178.
1076 You can get the latest version from https://sourceware.org/elfutils.
1078 * Multi-target debugging support
1080 GDB now supports debugging multiple target connections
1081 simultaneously. For example, you can now have each inferior
1082 connected to different remote servers running in different machines,
1083 or have one inferior debugging a local native process, an inferior
1084 debugging a core dump, etc.
1086 This support is experimental and comes with some limitations -- you
1087 can only resume multiple targets simultaneously if all targets
1088 support non-stop mode, and all remote stubs or servers must support
1089 the same set of remote protocol features exactly. See also "info
1090 connections" and "add-inferior -no-connection" below, and "maint set
1091 target-non-stop" in the user manual.
1093 * New features in the GDB remote stub, GDBserver
1095 ** GDBserver is now supported on ARC GNU/Linux.
1097 ** GDBserver is now supported on RISC-V GNU/Linux.
1099 ** GDBserver no longer supports these host triplets:
1101 i[34567]86-*-lynxos*
1110 i[34567]86-*-mingw32ce*
1112 * Debugging MS-Windows processes now sets $_exitsignal when the
1113 inferior is terminated by a signal, instead of setting $_exitcode.
1115 * Multithreaded symbol loading has now been enabled by default on systems
1116 that support it (see entry for GDB 9, below), providing faster
1117 performance for programs with many symbols.
1119 * The $_siginfo convenience variable now also works on Windows targets,
1120 and will display the EXCEPTION_RECORD of the last handled exception.
1122 * TUI windows can now be arranged horizontally.
1124 * The command history filename can now be set to the empty string
1125 either using 'set history filename' or by setting 'GDBHISTFILE=' in
1126 the environment. The effect of setting this filename to the empty
1127 string is that GDB will not try to load any previous command
1130 * On Windows targets, it is now possible to debug 32-bit programs with a
1135 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1136 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1137 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
1138 running process, this new option indicates whether to detect
1139 a mismatch between the current executable file loaded by GDB and the
1140 executable file used to start the process. If 'ask', the default,
1141 display a warning and ask the user whether to load the process
1142 executable file; if 'warn', just display a warning; if 'off', don't
1143 attempt to detect a mismatch.
1145 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1146 Define a new TUI layout, specifying its name and the windows that
1149 maintenance print xml-tdesc [FILE]
1150 Prints the current target description as an XML document. If the
1151 optional FILE is provided (which is an XML target description) then
1152 the target description is read from FILE into GDB, and then
1155 maintenance print core-file-backed-mappings
1156 Prints file-backed mappings loaded from a core file's note section.
1157 Output is expected to be similar to that of "info proc mappings".
1159 set debug fortran-array-slicing on|off
1160 show debug fortran-array-slicing
1161 Print debugging when taking slices of Fortran arrays.
1163 set fortran repack-array-slices on|off
1164 show fortran repack-array-slices
1165 When taking slices from Fortran arrays and strings, if the slice is
1166 non-contiguous within the original value then, when this option is
1167 on, the new value will be repacked into a single contiguous value.
1168 When this option is off, then the value returned will consist of a
1169 descriptor that describes the slice within the memory of the
1170 original parent value.
1174 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1175 The alias command can now specify default args for an alias.
1176 GDB automatically prepends the alias default args to the argument list
1177 provided explicitly by the user.
1178 For example, to have a backtrace with full details, you can define
1179 an alias 'bt_ALL' as
1180 'alias bt_ALL = backtrace -entry-values both -frame-arg all
1181 -past-main -past-entry -full'.
1182 Alias default arguments can also use a set of nested 'with' commands,
1183 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1184 defines the alias pp10 that will pretty print a maximum of 10 elements
1185 of the given expression (if the expression is an array).
1189 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
1190 BPF bpf-unknown-none
1195 ** gdb.register_window_type can be used to implement new TUI windows
1198 ** Dynamic types can now be queried. gdb.Type has a new attribute,
1199 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
1200 field of a dynamic type may have None for its "bitpos" attribute
1203 ** Commands written in Python can be in the "TUI" help class by
1204 registering with the new constant gdb.COMMAND_TUI.
1206 ** New method gdb.PendingFrame.architecture () to retrieve the
1207 architecture of the pending frame.
1209 ** New gdb.Architecture.registers method that returns a
1210 gdb.RegisterDescriptorIterator object, an iterator that returns
1211 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
1212 way to query the registers available for an architecture.
1214 ** New gdb.Architecture.register_groups method that returns a
1215 gdb.RegisterGroupIterator object, an iterator that returns
1216 gdb.RegisterGroup objects. The new RegisterGroup is a way to
1217 discover the available register groups.
1221 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1223 ** Procedures 'memory-port-read-buffer-size',
1224 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1225 and 'set-memory-port-write-buffer-size!' are deprecated. When
1226 using Guile 2.2 and later, users who need to control the size of
1227 a memory port's internal buffer can use the 'setvbuf' procedure.
1229 *** Changes in GDB 9
1231 * 'thread-exited' event is now available in the annotations interface.
1233 * New built-in convenience variables $_gdb_major and $_gdb_minor
1234 provide the GDB version. They are handy for conditionally using
1235 features available only in or since specific GDB versions, in
1236 scripts that should work error-free with many different versions,
1237 such as in system-wide init files.
1239 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1240 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1241 of the GDB settings and the GDB maintenance settings. They are handy
1242 for changing the logic of user defined commands depending on the
1243 current GDB settings.
1245 * GDB now supports Thread Local Storage (TLS) variables on several
1246 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1247 architectures require kernel changes. TLS is not yet supported for
1248 amd64 and i386 process core dumps.
1250 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1251 addresses that required unmasking are shown in the backtrace with the
1254 * Two new convenience functions $_cimag and $_creal that extract the
1255 imaginary and real parts respectively from complex numbers.
1257 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1258 provide the exitcode or exit status of the shell commands launched by
1259 GDB commands such as "shell", "pipe" and "make".
1261 * The command define-prefix can now define user defined prefix commands.
1262 User defined commands can now be defined using these user defined prefix
1265 * Command names can now use the . character.
1267 * The RX port now supports XML target descriptions.
1269 * GDB now shows the Ada task names at more places, e.g. in task switching
1272 * GDB can now be compiled with Python 3 on Windows.
1274 * New convenience variable $_ada_exception holds the address of the
1275 Ada exception being thrown. This is set by Ada-related catchpoints.
1277 * GDB can now place breakpoints on nested functions and subroutines in
1278 Fortran code. The '::' operator can be used between parent and
1279 child scopes when placing breakpoints, for example:
1281 (gdb) break outer_function::inner_function
1283 The 'outer_function::' prefix is only needed if 'inner_function' is
1284 not visible in the current scope.
1286 * In addition to the system-wide gdbinit file, if configured with
1287 --with-system-gdbinit-dir, GDB will now also load files in that directory
1288 as system gdbinit files, unless the -nx or -n flag is provided. Files
1289 with extensions .gdb, .py and .scm are supported as long as GDB was
1290 compiled with support for that language.
1292 * GDB now supports multithreaded symbol loading for higher performance.
1293 This feature is still in testing, so it is disabled by default. You
1294 can turn it on using 'maint set worker-threads unlimited'.
1298 ** The gdb.Value type has a new method 'format_string' which returns a
1299 string representing the value. The formatting is controlled by the
1300 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1301 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1302 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1304 ** gdb.Type has a new property 'objfile' which returns the objfile the
1305 type was defined in.
1307 ** The frame information printed by the python frame filtering code
1308 is now consistent with what the 'backtrace' command prints when
1309 there are no filters, or when the 'backtrace' '-no-filters' option
1312 ** The new function gdb.lookup_static_symbol can be used to look up
1313 symbols with static linkage.
1315 ** The new function gdb.lookup_static_symbols can be used to look up
1316 all static symbols with static linkage.
1318 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1319 'lookup_static_symbol' to lookup a symbol from this objfile only.
1321 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1322 this block (e.g. block['local_variable']).
1326 | [COMMAND] | SHELL_COMMAND
1327 | -d DELIM COMMAND DELIM SHELL_COMMAND
1328 pipe [COMMAND] | SHELL_COMMAND
1329 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1330 Executes COMMAND and sends its output to SHELL_COMMAND.
1331 With no COMMAND, repeat the last executed command
1332 and send its output to SHELL_COMMAND.
1334 define-prefix COMMAND
1335 Define or mark a command as a user-defined prefix command.
1337 with SETTING [VALUE] [-- COMMAND]
1338 w SETTING [VALUE] [-- COMMAND]
1339 Temporarily set SETTING, run COMMAND, and restore SETTING.
1340 Usage: with SETTING -- COMMAND
1341 With no COMMAND, repeats the last executed command.
1342 SETTING is any GDB setting you can change with the "set"
1343 subcommands. For example, 'with language c -- print someobj'
1344 temporarily switches to the C language in order to print someobj.
1345 Settings can be combined: 'w lang c -- w print elements unlimited --
1346 usercmd' switches to the C language and runs usercmd with no limit
1347 of array elements to print.
1349 maint with SETTING [VALUE] [-- COMMAND]
1350 Like "with", but works with "maintenance set" settings.
1352 set may-call-functions [on|off]
1353 show may-call-functions
1354 This controls whether GDB will attempt to call functions in
1355 the program, such as with expressions in the print command. It
1356 defaults to on. Calling functions in the program being debugged
1357 can have undesired side effects. It is now possible to forbid
1358 such function calls. If function calls are forbidden, GDB will throw
1359 an error when a command (such as print expression) calls a function
1362 set print finish [on|off]
1364 This controls whether the `finish' command will display the value
1365 that is returned by the current function. When `off', the value is
1366 still entered into the value history, but it is not printed. The
1370 show print max-depth
1371 Allows deeply nested structures to be simplified when printing by
1372 replacing deeply nested parts (beyond the max-depth) with ellipses.
1373 The default max-depth is 20, but this can be set to unlimited to get
1374 the old behavior back.
1376 set print raw-values [on|off]
1377 show print raw-values
1378 By default, GDB applies the enabled pretty printers when printing a
1379 value. This allows to ignore the enabled pretty printers for a series
1380 of commands. The default is 'off'.
1382 set logging debugredirect [on|off]
1383 By default, GDB debug output will go to both the terminal and the logfile.
1384 Set if you want debug output to go only to the log file.
1386 set style title foreground COLOR
1387 set style title background COLOR
1388 set style title intensity VALUE
1389 Control the styling of titles.
1391 set style highlight foreground COLOR
1392 set style highlight background COLOR
1393 set style highlight intensity VALUE
1394 Control the styling of highlightings.
1396 maint set worker-threads
1397 maint show worker-threads
1398 Control the number of worker threads that can be used by GDB. The
1399 default is 0. "unlimited" lets GDB choose a number that is
1400 reasonable. Currently worker threads are only used when demangling
1401 the names of linker symbols.
1403 set style tui-border foreground COLOR
1404 set style tui-border background COLOR
1405 Control the styling of TUI borders.
1407 set style tui-active-border foreground COLOR
1408 set style tui-active-border background COLOR
1409 Control the styling of the active TUI border.
1411 maint set test-settings KIND
1412 maint show test-settings KIND
1413 A set of commands used by the testsuite for exercising the settings
1416 maint set tui-resize-message [on|off]
1417 maint show tui-resize-message
1418 Control whether GDB prints a message each time the terminal is
1419 resized when in TUI mode. This is primarily useful for testing the
1422 set print frame-info [short-location|location|location-and-address
1423 |source-and-location|source-line|auto]
1424 show print frame-info
1425 This controls what frame information is printed by the commands printing
1426 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1427 'frame', 'stepi'. The python frame filtering also respect this setting.
1428 The 'backtrace' '-frame-info' option can override this global setting.
1430 set tui compact-source
1431 show tui compact-source
1433 Enable the "compact" display mode for the TUI source window. The
1434 compact display uses only as much space as is needed for the line
1435 numbers in the current file, and only a single space to separate the
1436 line numbers from the source.
1438 info modules [-q] [REGEXP]
1439 Return a list of Fortran modules matching REGEXP, or all modules if
1442 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1443 Return a list of functions within all modules, grouped by module.
1444 The list of functions can be restricted with the optional regular
1445 expressions. MODULE_REGEXP matches against the module name,
1446 TYPE_REGEXP matches against the function type signature, and REGEXP
1447 matches against the function name.
1449 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1450 Return a list of variables within all modules, grouped by module.
1451 The list of variables can be restricted with the optional regular
1452 expressions. MODULE_REGEXP matches against the module name,
1453 TYPE_REGEXP matches against the variable type, and REGEXP matches
1454 against the variable name.
1456 set debug remote-packet-max-chars
1457 show debug remote-packet-max-chars
1458 Controls the number of characters to output in a remote packet when using
1460 The default is 512 bytes.
1463 Lists the target connections currently in use.
1468 The "help" command uses the title style to enhance the
1469 readibility of its output by styling the classes and
1473 Similarly to "help", the "apropos" command also uses the
1474 title style for the command names. "apropos" accepts now
1475 a flag "-v" (verbose) to show the full documentation
1476 of matching commands and to use the highlight style to mark
1477 the documentation parts matching REGEXP.
1481 The GDB printf and eval commands can now print C-style and Ada-style
1482 string convenience variables without calling functions in the program.
1483 This allows to do formatted printing of strings without having
1484 a running inferior, or when debugging a core dump.
1486 info sources [-dirname | -basename] [--] [REGEXP]
1487 This command has now optional arguments to only print the files
1488 whose names match REGEXP. The arguments -dirname and -basename
1489 allow to restrict matching respectively to the dirname and basename
1493 The "show style" and its subcommands are now styling
1494 a style name in their output using its own style, to help
1495 the user visualize the different styles.
1497 set print frame-arguments
1498 The new value 'presence' indicates to only indicate the presence of
1499 arguments using ..., instead of printing argument names and values.
1501 set print raw-frame-arguments
1502 show print raw-frame-arguments
1504 These commands replace the similarly-named "set/show print raw
1505 frame-arguments" commands (now with a dash instead of a space). The
1506 old commands are now deprecated and may be removed in a future
1509 add-inferior [-no-connection]
1510 The add-inferior command now supports a "-no-connection" flag that
1511 makes the new inferior start with no target connection associated.
1512 By default, the new inferior inherits the target connection of the
1513 current inferior. See also "info connections".
1516 This command's output now includes a new "Connection" column
1517 indicating which target connection an inferior is bound to. See
1518 "info connections" above.
1520 maint test-options require-delimiter
1521 maint test-options unknown-is-error
1522 maint test-options unknown-is-operand
1523 maint show test-options-completion-result
1524 Commands used by the testsuite to validate the command options
1527 focus, winheight, +, -, >, <
1528 These commands are now case-sensitive.
1530 * New command options, command completion
1532 GDB now has a standard infrastructure to support dash-style command
1533 options ('-OPT'). One benefit is that commands that use it can
1534 easily support completion of command line arguments. Try "CMD
1535 -[TAB]" or "help CMD" to find options supported by a command. Over
1536 time, we intend to migrate most commands to this infrastructure. A
1537 number of commands got support for new command options in this
1540 ** The "print" and "compile print" commands now support a number of
1541 options that allow overriding relevant global print settings as
1542 set by "set print" subcommands:
1546 -array-indexes [on|off]
1547 -elements NUMBER|unlimited
1551 -raw-values [on|off]
1552 -repeats NUMBER|unlimited
1553 -static-members [on|off]
1558 Note that because the "print"/"compile print" commands accept
1559 arbitrary expressions which may look like options (including
1560 abbreviations), if you specify any command option, then you must
1561 use a double dash ("--") to mark the end of argument processing.
1563 ** The "backtrace" command now supports a number of options that
1564 allow overriding relevant global print settings as set by "set
1565 backtrace" and "set print" subcommands:
1567 -entry-values no|only|preferred|if-needed|both|compact|default
1568 -frame-arguments all|scalars|none
1569 -raw-frame-arguments [on|off]
1570 -frame-info auto|source-line|location|source-and-location
1571 |location-and-address|short-location
1573 -past-entry [on|off]
1575 In addition, the full/no-filters/hide qualifiers are now also
1576 exposed as command options too:
1582 ** The "frame apply", "tfaas" and "faas" commands similarly now
1583 support the following options:
1586 -past-entry [on|off]
1588 ** The new "info sources" options -dirname and -basename options
1589 are using the standard '-OPT' infrastructure.
1591 All options above can also be abbreviated. The argument of boolean
1592 (on/off) options can be 0/1 too, and also the argument is assumed
1593 "on" if omitted. This allows writing compact command invocations,
1596 (gdb) p -ra -p -o 0 -- *myptr
1598 The above is equivalent to:
1600 (gdb) print -raw-values -pretty -object off -- *myptr
1602 ** The "info types" command now supports the '-q' flag to disable
1603 printing of some header information in a similar fashion to "info
1604 variables" and "info functions".
1606 ** The "info variables", "info functions", and "whereis" commands
1607 now take a '-n' flag that excludes non-debug symbols (symbols
1608 from the symbol table, not from the debug info such as DWARF)
1611 * Completion improvements
1613 ** GDB can now complete the options of the "thread apply all" and
1614 "taas" commands, and their "-ascending" option can now be
1617 ** GDB can now complete the options of the "info threads", "info
1618 functions", "info variables", "info locals", and "info args"
1621 ** GDB can now complete the options of the "compile file" and
1622 "compile code" commands. The "compile file" command now
1623 completes on filenames.
1625 ** GDB can now complete the backtrace command's
1626 "full/no-filters/hide" qualifiers.
1628 * In settings, you can now abbreviate "unlimited".
1630 E.g., "set print elements u" is now equivalent to "set print
1631 elements unlimited".
1636 This lists all the possible completions for the rest of the line, if it
1637 were to be given as a command itself. This is intended for use by MI
1638 frontends in cases when separate CLI and MI channels cannot be used.
1640 -catch-throw, -catch-rethrow, and -catch-catch
1641 These can be used to catch C++ exceptions in a similar fashion to
1642 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1644 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1645 These commands are the MI equivalent of the CLI commands 'info
1646 functions', 'info types', and 'info variables' respectively.
1648 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1651 -symbol-info-module-functions and -symbol-info-module-variables.
1652 These commands are the MI equivalent of the CLI commands 'info
1653 module functions' and 'info module variables'.
1657 ** The default version of the MI interpreter is now 3 (-i=mi3).
1659 ** The output of information about multi-location breakpoints (which is
1660 syntactically incorrect in MI 2) has changed in MI 3. This affects
1661 the following commands and events:
1665 - =breakpoint-created
1666 - =breakpoint-modified
1668 The -fix-multi-location-breakpoint-output command can be used to enable
1669 this behavior with previous MI versions.
1671 ** Backtraces and frames include a new optional field addr_flags which is
1672 given after the addr field. On AArch64 this contains PAC if the address
1673 has been masked in the frame. On all other targets the field is not
1678 The testsuite now creates the files gdb.cmd (containing the arguments
1679 used to launch GDB) and gdb.in (containing all the commands sent to
1680 GDB) in the output directory for each test script. Multiple invocations
1681 are appended with .1, .2, .3 etc.
1683 * Building GDB and GDBserver now requires GNU make >= 3.82.
1685 Using another implementation of the make program or an earlier version of
1686 GNU make to build GDB or GDBserver is not supported.
1688 * Building GDB now requires GNU readline >= 7.0.
1690 GDB now bundles GNU readline 8.0, but if you choose to use
1691 --with-system-readline, only readline >= 7.0 can be used.
1693 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1694 from .inputrc to bind keys in this keymap. This feature is only
1695 available when gdb is built against GNU readline 8.0 or later.
1697 * Removed targets and native configurations
1699 GDB no longer supports debugging the Cell Broadband Engine. This includes
1700 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1701 of Cell/B.E. applications that use both the PPU and SPU architectures.
1707 * Removed targets and native configurations
1709 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1710 sparc*-*-solaris2.10
1712 *** Changes in GDB 8.3
1714 * GDB and GDBserver now support access to additional registers on
1715 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1718 * GDB now has experimental support for the compilation and injection of
1719 C++ source code into the inferior. This beta release does not include
1720 support for several language features, such as templates, constructors,
1723 This feature requires GCC 7.1 or higher built with libcp1.so
1726 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1727 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1728 'ADDRESS:PORT' method.
1730 * DWARF index cache: GDB can now automatically save indices of DWARF
1731 symbols on disk to speed up further loading of the same binaries.
1733 * Ada task switching is now supported on aarch64-elf targets when
1734 debugging a program using the Ravenscar Profile. For more information,
1735 see the "Tasking Support when using the Ravenscar Profile" section
1736 in the GDB user manual.
1738 * GDB in batch mode now exits with status 1 if the last command to be
1741 * The RISC-V target now supports target descriptions.
1743 * System call catchpoints now support system call aliases on FreeBSD.
1744 When the ABI of a system call changes in FreeBSD, this is
1745 implemented by leaving a compatibility system call using the old ABI
1746 at the existing number and allocating a new system call number for
1747 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1748 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1749 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1750 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1751 so that a system call catchpoint for the 'kevent' system call will
1752 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1753 binaries. This ensures that 'kevent' system calls are caught for
1754 binaries using either the old or new ABIs.
1756 * Terminal styling is now available for the CLI and the TUI. GNU
1757 Source Highlight can additionally be used to provide styling of
1758 source code snippets. See the "set style" commands, below, for more
1761 * Removed support for old demangling styles arm, edg, gnu, hp and
1766 set debug compile-cplus-types
1767 show debug compile-cplus-types
1768 Control the display of debug output about type conversion in the
1769 C++ compile feature. Commands have no effect while compiling
1770 for other languages.
1774 Control whether debug output about files/functions skipping is
1777 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1778 Apply a command to some frames.
1779 FLAG arguments allow to control what output to produce and how to handle
1780 errors raised when applying COMMAND to a frame.
1783 Apply a command to all threads (ignoring errors and empty output).
1784 Shortcut for 'thread apply all -s COMMAND'.
1787 Apply a command to all frames (ignoring errors and empty output).
1788 Shortcut for 'frame apply all -s COMMAND'.
1791 Apply a command to all frames of all threads (ignoring errors and empty
1793 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1795 maint set dwarf unwinders (on|off)
1796 maint show dwarf unwinders
1797 Control whether DWARF unwinders can be used.
1800 Display a list of open files for a process.
1804 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1805 These commands all now take a frame specification which
1806 is either a frame level, or one of the keywords 'level', 'address',
1807 'function', or 'view' followed by a parameter. Selecting a frame by
1808 address, or viewing a frame outside the current backtrace now
1809 requires the use of a keyword. Selecting a frame by level is
1810 unchanged. The MI comment "-stack-select-frame" is unchanged.
1812 target remote FILENAME
1813 target extended-remote FILENAME
1814 If FILENAME is a Unix domain socket, GDB will attempt to connect
1815 to this socket instead of opening FILENAME as a character device.
1817 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1818 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1819 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1820 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1821 These commands can now print only the searched entities
1822 matching the provided regexp(s), giving a condition
1823 on the entity names or entity types. The flag -q disables
1824 printing headers or informations messages.
1830 These commands now determine the syntax for the shown entities
1831 according to the language chosen by `set language'. In particular,
1832 `set language auto' means to automatically choose the language of
1835 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1836 The 'thread apply' command accepts new FLAG arguments.
1837 FLAG arguments allow to control what output to produce and how to handle
1838 errors raised when applying COMMAND to a thread.
1840 set tui tab-width NCHARS
1841 show tui tab-width NCHARS
1842 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1844 set style enabled [on|off]
1846 Enable or disable terminal styling. Styling is enabled by default
1847 on most hosts, but disabled by default when in batch mode.
1849 set style sources [on|off]
1851 Enable or disable source code styling. Source code styling is
1852 enabled by default, but only takes effect if styling in general is
1853 enabled, and if GDB was linked with GNU Source Highlight.
1855 set style filename foreground COLOR
1856 set style filename background COLOR
1857 set style filename intensity VALUE
1858 Control the styling of file names.
1860 set style function foreground COLOR
1861 set style function background COLOR
1862 set style function intensity VALUE
1863 Control the styling of function names.
1865 set style variable foreground COLOR
1866 set style variable background COLOR
1867 set style variable intensity VALUE
1868 Control the styling of variable names.
1870 set style address foreground COLOR
1871 set style address background COLOR
1872 set style address intensity VALUE
1873 Control the styling of addresses.
1877 ** The '-data-disassemble' MI command now accepts an '-a' option to
1878 disassemble the whole function surrounding the given program
1879 counter value or function name. Support for this feature can be
1880 verified by using the "-list-features" command, which should
1881 contain "data-disassemble-a-option".
1883 ** Command responses and notifications that include a frame now include
1884 the frame's architecture in a new "arch" attribute.
1886 * New native configurations
1888 GNU/Linux/RISC-V riscv*-*-linux*
1889 FreeBSD/riscv riscv*-*-freebsd*
1893 GNU/Linux/RISC-V riscv*-*-linux*
1894 CSKY ELF csky*-*-elf
1895 CSKY GNU/LINUX csky*-*-linux
1896 FreeBSD/riscv riscv*-*-freebsd*
1898 GNU/Linux/OpenRISC or1k*-*-linux*
1902 GDB no longer supports native debugging on versions of MS-Windows
1907 ** GDB no longer supports Python versions less than 2.6.
1909 ** The gdb.Inferior type has a new 'progspace' property, which is the program
1910 space associated to that inferior.
1912 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
1913 of objfiles associated to that program space.
1915 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
1916 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
1919 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
1920 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
1921 correct and did not work properly.
1923 ** The gdb.Value type has a new constructor, which is used to construct a
1924 gdb.Value from a Python buffer object and a gdb.Type.
1930 Enable or disable the undefined behavior sanitizer. This is
1931 disabled by default, but passing --enable-ubsan=yes or
1932 --enable-ubsan=auto to configure will enable it. Enabling this can
1933 cause a performance penalty. The undefined behavior sanitizer was
1934 first introduced in GCC 4.9.
1936 *** Changes in GDB 8.2
1938 * The 'set disassembler-options' command now supports specifying options
1939 for the MIPS target.
1941 * The 'symbol-file' command now accepts an '-o' option to add a relative
1942 offset to all sections.
1944 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
1945 a relative offset to all sections, but it allows to override the load
1946 address of individual sections using '-s'.
1948 * The 'add-symbol-file' command no longer requires the second argument
1949 (address of the text section).
1951 * The endianness used with the 'set endian auto' mode in the absence of
1952 an executable selected for debugging is now the last endianness chosen
1953 either by one of the 'set endian big' and 'set endian little' commands
1954 or by inferring from the last executable used, rather than the startup
1957 * The pager now allows a "c" response, meaning to disable the pager
1958 for the rest of the current command.
1960 * The commands 'info variables/functions/types' now show the source line
1961 numbers of symbol definitions when available.
1963 * 'info proc' now works on running processes on FreeBSD systems and core
1964 files created on FreeBSD systems.
1966 * C expressions can now use _Alignof, and C++ expressions can now use
1969 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
1970 the vector length while the process is running.
1976 Control display of debugging info regarding the FreeBSD native target.
1978 set|show varsize-limit
1979 This new setting allows the user to control the maximum size of Ada
1980 objects being printed when those objects have a variable type,
1981 instead of that maximum size being hardcoded to 65536 bytes.
1983 set|show record btrace cpu
1984 Controls the processor to be used for enabling errata workarounds for
1985 branch trace decode.
1987 maint check libthread-db
1988 Run integrity checks on the current inferior's thread debugging
1991 maint set check-libthread-db (on|off)
1992 maint show check-libthread-db
1993 Control whether to run integrity checks on inferior specific thread
1994 debugging libraries as they are loaded. The default is not to
1995 perform such checks.
1999 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2001 ** The commands attached to a breakpoint can be set by assigning to
2002 the breakpoint's "commands" field.
2004 ** gdb.execute can now execute multi-line gdb commands.
2006 ** The new functions gdb.convenience_variable and
2007 gdb.set_convenience_variable can be used to get and set the value
2008 of convenience variables.
2010 ** A gdb.Parameter will no longer print the "set" help text on an
2011 ordinary "set"; instead by default a "set" will be silent unless
2012 the get_set_string method returns a non-empty string.
2016 RiscV ELF riscv*-*-elf
2018 * Removed targets and native configurations
2020 m88k running OpenBSD m88*-*-openbsd*
2021 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2022 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2023 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2025 * Aarch64/Linux hardware watchpoints improvements
2027 Hardware watchpoints on unaligned addresses are now properly
2028 supported when running Linux kernel 4.10 or higher: read and access
2029 watchpoints are no longer spuriously missed, and all watchpoints
2030 lengths between 1 and 8 bytes are supported. On older kernels,
2031 watchpoints set on unaligned addresses are no longer missed, with
2032 the tradeoff that there is a possibility of false hits being
2037 --enable-codesign=CERT
2038 This can be used to invoke "codesign -s CERT" after building gdb.
2039 This option is useful on macOS, where code signing is required for
2040 gdb to work properly.
2042 --disable-gdbcli has been removed
2043 This is now silently accepted, but does nothing.
2045 *** Changes in GDB 8.1
2047 * GDB now supports dynamically creating arbitrary register groups specified
2048 in XML target descriptions. This allows for finer grain grouping of
2049 registers on systems with a large amount of registers.
2051 * The 'ptype' command now accepts a '/o' flag, which prints the
2052 offsets and sizes of fields in a struct, like the pahole(1) tool.
2054 * New "--readnever" command line option instructs GDB to not read each
2055 symbol file's symbolic debug information. This makes startup faster
2056 but at the expense of not being able to perform symbolic debugging.
2057 This option is intended for use cases where symbolic debugging will
2058 not be used, e.g., when you only need to dump the debuggee's core.
2060 * GDB now uses the GNU MPFR library, if available, to emulate target
2061 floating-point arithmetic during expression evaluation when the target
2062 uses different floating-point formats than the host. At least version
2063 3.1 of GNU MPFR is required.
2065 * GDB now supports access to the guarded-storage-control registers and the
2066 software-based guarded-storage broadcast control registers on IBM z14.
2068 * On Unix systems, GDB now supports transmitting environment variables
2069 that are to be set or unset to GDBserver. These variables will
2070 affect the environment to be passed to the remote inferior.
2072 To inform GDB of environment variables that are to be transmitted to
2073 GDBserver, use the "set environment" command. Only user set
2074 environment variables are sent to GDBserver.
2076 To inform GDB of environment variables that are to be unset before
2077 the remote inferior is started by the GDBserver, use the "unset
2078 environment" command.
2080 * Completion improvements
2082 ** GDB can now complete function parameters in linespecs and
2083 explicit locations without quoting. When setting breakpoints,
2084 quoting around functions names to help with TAB-completion is
2085 generally no longer necessary. For example, this now completes
2088 (gdb) b function(in[TAB]
2089 (gdb) b function(int)
2091 Related, GDB is no longer confused with completing functions in
2092 C++ anonymous namespaces:
2095 (gdb) b (anonymous namespace)::[TAB][TAB]
2096 (anonymous namespace)::a_function()
2097 (anonymous namespace)::b_function()
2099 ** GDB now has much improved linespec and explicit locations TAB
2100 completion support, that better understands what you're
2101 completing and offers better suggestions. For example, GDB no
2102 longer offers data symbols as possible completions when you're
2103 setting a breakpoint.
2105 ** GDB now TAB-completes label symbol names.
2107 ** The "complete" command now mimics TAB completion accurately.
2109 * New command line options (gcore)
2112 Dump all memory mappings.
2114 * Breakpoints on C++ functions are now set on all scopes by default
2116 By default, breakpoints on functions/methods are now interpreted as
2117 specifying all functions with the given name ignoring missing
2118 leading scopes (namespaces and classes).
2120 For example, assuming a C++ program with symbols named:
2125 both commands "break func()" and "break B::func()" set a breakpoint
2128 You can use the new flag "-qualified" to override this. This makes
2129 GDB interpret the specified function name as a complete
2130 fully-qualified name instead. For example, using the same C++
2131 program, the "break -q B::func" command sets a breakpoint on
2132 "B::func", only. A parameter has been added to the Python
2133 gdb.Breakpoint constructor to achieve the same result when creating
2134 a breakpoint from Python.
2136 * Breakpoints on functions marked with C++ ABI tags
2138 GDB can now set breakpoints on functions marked with C++ ABI tags
2139 (e.g., [abi:cxx11]). See here for a description of ABI tags:
2140 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2142 Functions with a C++11 abi tag are demangled/displayed like this:
2144 function[abi:cxx11](int)
2147 You can now set a breakpoint on such functions simply as if they had
2150 (gdb) b function(int)
2152 Or if you need to disambiguate between tags, like:
2154 (gdb) b function[abi:other_tag](int)
2156 Tab completion was adjusted accordingly as well.
2160 ** New events gdb.new_inferior, gdb.inferior_deleted, and
2161 gdb.new_thread are emitted. See the manual for further
2162 description of these.
2164 ** A new function, "gdb.rbreak" has been added to the Python API.
2165 This function allows the setting of a large number of breakpoints
2166 via a regex pattern in Python. See the manual for further details.
2168 ** Python breakpoints can now accept explicit locations. See the
2169 manual for a further description of this feature.
2172 * New features in the GDB remote stub, GDBserver
2174 ** GDBserver is now able to start inferior processes with a
2175 specified initial working directory.
2177 The user can set the desired working directory to be used from
2178 GDB using the new "set cwd" command.
2180 ** New "--selftest" command line option runs some GDBserver self
2181 tests. These self tests are disabled in releases.
2183 ** On Unix systems, GDBserver now does globbing expansion and variable
2184 substitution in inferior command line arguments.
2186 This is done by starting inferiors using a shell, like GDB does.
2187 See "set startup-with-shell" in the user manual for how to disable
2188 this from GDB when using "target extended-remote". When using
2189 "target remote", you can disable the startup with shell by using the
2190 new "--no-startup-with-shell" GDBserver command line option.
2192 ** On Unix systems, GDBserver now supports receiving environment
2193 variables that are to be set or unset from GDB. These variables
2194 will affect the environment to be passed to the inferior.
2196 * When catching an Ada exception raised with a message, GDB now prints
2197 the message in the catchpoint hit notification. In GDB/MI mode, that
2198 information is provided as an extra field named "exception-message"
2199 in the *stopped notification.
2201 * Trait objects can now be inspected When debugging Rust code. This
2202 requires compiler support which will appear in Rust 1.24.
2204 * New remote packets
2206 QEnvironmentHexEncoded
2207 Inform GDBserver of an environment variable that is to be passed to
2208 the inferior when starting it.
2211 Inform GDBserver of an environment variable that is to be unset
2212 before starting the remote inferior.
2215 Inform GDBserver that the environment should be reset (i.e.,
2216 user-set environment variables should be unset).
2219 Indicates whether the inferior must be started with a shell or not.
2222 Tell GDBserver that the inferior to be started should use a specific
2225 * The "maintenance print c-tdesc" command now takes an optional
2226 argument which is the file name of XML target description.
2228 * The "maintenance selftest" command now takes an optional argument to
2229 filter the tests to be run.
2231 * The "enable", and "disable" commands now accept a range of
2232 breakpoint locations, e.g. "enable 1.3-5".
2237 Set and show the current working directory for the inferior.
2239 set|show compile-gcc
2240 Set and show compilation command used for compiling and injecting code
2241 with the 'compile' commands.
2243 set debug separate-debug-file
2244 show debug separate-debug-file
2245 Control the display of debug output about separate debug file search.
2247 set dump-excluded-mappings
2248 show dump-excluded-mappings
2249 Control whether mappings marked with the VM_DONTDUMP flag should be
2250 dumped when generating a core file.
2252 maint info selftests
2253 List the registered selftests.
2256 Start the debugged program stopping at the first instruction.
2259 Control display of debugging messages related to OpenRISC targets.
2261 set|show print type nested-type-limit
2262 Set and show the limit of nesting level for nested types that the
2263 type printer will show.
2265 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2268 * Safer/improved support for debugging with no debug info
2270 GDB no longer assumes functions with no debug information return
2273 This means that GDB now refuses to call such functions unless you
2274 tell it the function's type, by either casting the call to the
2275 declared return type, or by casting the function to a function
2276 pointer of the right type, and calling that:
2278 (gdb) p getenv ("PATH")
2279 'getenv' has unknown return type; cast the call to its declared return type
2280 (gdb) p (char *) getenv ("PATH")
2281 $1 = 0x7fffffffe "/usr/local/bin:/"...
2282 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2283 $2 = 0x7fffffffe "/usr/local/bin:/"...
2285 Similarly, GDB no longer assumes that global variables with no debug
2286 info have type 'int', and refuses to print the variable's value
2287 unless you tell it the variable's type:
2290 'var' has unknown type; cast it to its declared type
2294 * New native configurations
2296 FreeBSD/aarch64 aarch64*-*-freebsd*
2297 FreeBSD/arm arm*-*-freebsd*
2301 FreeBSD/aarch64 aarch64*-*-freebsd*
2302 FreeBSD/arm arm*-*-freebsd*
2303 OpenRISC ELF or1k*-*-elf
2305 * Removed targets and native configurations
2307 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2309 *** Changes in GDB 8.0
2311 * GDB now supports access to the PKU register on GNU/Linux. The register is
2312 added by the Memory Protection Keys for Userspace feature which will be
2313 available in future Intel CPUs.
2315 * GDB now supports C++11 rvalue references.
2319 ** New functions to start, stop and access a running btrace recording.
2320 ** Rvalue references are now supported in gdb.Type.
2322 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2325 * Building GDB and GDBserver now requires a C++11 compiler.
2327 For example, GCC 4.8 or later.
2329 It is no longer possible to build GDB or GDBserver with a C
2330 compiler. The --disable-build-with-cxx configure option has been
2333 * Building GDB and GDBserver now requires GNU make >= 3.81.
2335 It is no longer supported to build GDB or GDBserver with another
2336 implementation of the make program or an earlier version of GNU make.
2338 * Native debugging on MS-Windows supports command-line redirection
2340 Command-line arguments used for starting programs on MS-Windows can
2341 now include redirection symbols supported by native Windows shells,
2342 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2343 as "run", "start", and "set args", as well as the corresponding MI
2346 * Support for thread names on MS-Windows.
2348 GDB now catches and handles the special exception that programs
2349 running on MS-Windows use to assign names to threads in the
2352 * Support for Java programs compiled with gcj has been removed.
2354 * User commands now accept an unlimited number of arguments.
2355 Previously, only up to 10 was accepted.
2357 * The "eval" command now expands user-defined command arguments.
2359 This makes it easier to process a variable number of arguments:
2364 eval "print $arg%d", $i
2369 * Target descriptions can now describe registers for sparc32 and sparc64.
2371 * GDB now supports DWARF version 5 (debug information format).
2372 Its .debug_names index is not yet supported.
2374 * New native configurations
2376 FreeBSD/mips mips*-*-freebsd
2380 Synopsys ARC arc*-*-elf32
2381 FreeBSD/mips mips*-*-freebsd
2383 * Removed targets and native configurations
2385 Alpha running FreeBSD alpha*-*-freebsd*
2386 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2391 Erases all the flash memory regions reported by the target.
2393 maint print arc arc-instruction address
2394 Print internal disassembler information about instruction at a given address.
2398 set disassembler-options
2399 show disassembler-options
2400 Controls the passing of target specific information to the disassembler.
2401 If it is necessary to specify more than one disassembler option then
2402 multiple options can be placed together into a comma separated list.
2403 The default value is the empty string. Currently, the only supported
2404 targets are ARM, PowerPC and S/390.
2409 Erases all the flash memory regions reported by the target. This is
2410 equivalent to the CLI command flash-erase.
2412 -file-list-shared-libraries
2413 List the shared libraries in the program. This is
2414 equivalent to the CLI command "info shared".
2417 Catchpoints stopping the program when Ada exceptions are
2418 handled. This is equivalent to the CLI command "catch handlers".
2420 *** Changes in GDB 7.12
2422 * GDB and GDBserver now build with a C++ compiler by default.
2424 The --enable-build-with-cxx configure option is now enabled by
2425 default. One must now explicitly configure with
2426 --disable-build-with-cxx in order to build with a C compiler. This
2427 option will be removed in a future release.
2429 * GDBserver now supports recording btrace without maintaining an active
2432 * GDB now supports a negative repeat count in the 'x' command to examine
2433 memory backward from the given address. For example:
2436 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2437 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2438 (gdb) x/-5i 0x0000000000400580
2439 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2440 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2441 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2442 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2443 0x40057b <main(int, char**)+25>:
2444 callq 0x400536 <Func1(int, char const*)>
2446 * Fortran: Support structures with fields of dynamic types and
2447 arrays of dynamic types.
2449 * The symbol dumping maintenance commands have new syntax.
2450 maint print symbols [-pc address] [--] [filename]
2451 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2452 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2453 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2454 maint print msymbols [-objfile objfile] [--] [filename]
2456 * GDB now supports multibit bitfields and enums in target register
2459 * New Python-based convenience function $_as_string(val), which returns
2460 the textual representation of a value. This function is especially
2461 useful to obtain the text label of an enum value.
2463 * Intel MPX bound violation handling.
2465 Segmentation faults caused by a Intel MPX boundary violation
2466 now display the kind of violation (upper or lower), the memory
2467 address accessed and the memory bounds, along with the usual
2468 signal received and code location.
2472 Program received signal SIGSEGV, Segmentation fault
2473 Upper bound violation while accessing address 0x7fffffffc3b3
2474 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2475 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2477 * Rust language support.
2478 GDB now supports debugging programs written in the Rust programming
2479 language. See https://www.rust-lang.org/ for more information about
2482 * Support for running interpreters on specified input/output devices
2484 GDB now supports a new mechanism that allows frontends to provide
2485 fully featured GDB console views, as a better alternative to
2486 building such views on top of the "-interpreter-exec console"
2487 command. See the new "new-ui" command below. With that command,
2488 frontends can now start GDB in the traditional command-line mode
2489 running in an embedded terminal emulator widget, and create a
2490 separate MI interpreter running on a specified i/o device. In this
2491 way, GDB handles line editing, history, tab completion, etc. in the
2492 console all by itself, and the GUI uses the separate MI interpreter
2493 for its own control and synchronization, invisible to the command
2496 * The "catch syscall" command catches groups of related syscalls.
2498 The "catch syscall" command now supports catching a group of related
2499 syscalls using the 'group:' or 'g:' prefix.
2504 skip -gfile file-glob-pattern
2505 skip -function function
2506 skip -rfunction regular-expression
2507 A generalized form of the skip command, with new support for
2508 glob-style file names and regular expressions for function names.
2509 Additionally, a file spec and a function spec may now be combined.
2511 maint info line-table REGEXP
2512 Display the contents of GDB's internal line table data structure.
2515 Run any GDB unit tests that were compiled in.
2518 Start a new user interface instance running INTERP as interpreter,
2519 using the TTY file for input/output.
2523 ** gdb.Breakpoint objects have a new attribute "pending", which
2524 indicates whether the breakpoint is pending.
2525 ** Three new breakpoint-related events have been added:
2526 gdb.breakpoint_created, gdb.breakpoint_modified, and
2527 gdb.breakpoint_deleted.
2529 signal-event EVENTID
2530 Signal ("set") the given MS-Windows event object. This is used in
2531 conjunction with the Windows JIT debugging (AeDebug) support, where
2532 the OS suspends a crashing process until a debugger can attach to
2533 it. Resuming the crashing process, in order to debug it, is done by
2534 signalling an event.
2536 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2537 was added in GDBserver, including JIT compiling fast tracepoint's
2538 conditional expression bytecode into native code.
2540 * Support for various remote target protocols and ROM monitors has
2543 target m32rsdi Remote M32R debugging over SDI
2544 target mips MIPS remote debugging protocol
2545 target pmon PMON ROM monitor
2546 target ddb NEC's DDB variant of PMON for Vr4300
2547 target rockhopper NEC RockHopper variant of PMON
2548 target lsi LSI variant of PMO
2550 * Support for tracepoints and fast tracepoints on powerpc-linux,
2551 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2552 including JIT compiling fast tracepoint's conditional expression
2553 bytecode into native code.
2555 * MI async record =record-started now includes the method and format used for
2556 recording. For example:
2558 =record-started,thread-group="i1",method="btrace",format="bts"
2560 * MI async record =thread-selected now includes the frame field. For example:
2562 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2566 Andes NDS32 nds32*-*-elf
2568 *** Changes in GDB 7.11
2570 * GDB now supports debugging kernel-based threads on FreeBSD.
2572 * Per-inferior thread numbers
2574 Thread numbers are now per inferior instead of global. If you're
2575 debugging multiple inferiors, GDB displays thread IDs using a
2576 qualified INF_NUM.THR_NUM form. For example:
2580 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2581 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2582 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2583 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2585 As consequence, thread numbers as visible in the $_thread
2586 convenience variable and in Python's InferiorThread.num attribute
2587 are no longer unique between inferiors.
2589 GDB now maintains a second thread ID per thread, referred to as the
2590 global thread ID, which is the new equivalent of thread numbers in
2591 previous releases. See also $_gthread below.
2593 For backwards compatibility, MI's thread IDs always refer to global
2596 * Commands that accept thread IDs now accept the qualified
2597 INF_NUM.THR_NUM form as well. For example:
2600 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2603 * In commands that accept a list of thread IDs, you can now refer to
2604 all threads of an inferior using a star wildcard. GDB accepts
2605 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2606 refer to all threads of the current inferior. For example, "info
2609 * You can use "info threads -gid" to display the global thread ID of
2612 * The new convenience variable $_gthread holds the global number of
2615 * The new convenience variable $_inferior holds the number of the
2618 * GDB now displays the ID and name of the thread that hit a breakpoint
2619 or received a signal, if your program is multi-threaded. For
2622 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2623 Thread 1 "main" received signal SIGINT, Interrupt.
2625 * Record btrace now supports non-stop mode.
2627 * Support for tracepoints on aarch64-linux was added in GDBserver.
2629 * The 'record instruction-history' command now indicates speculative execution
2630 when using the Intel Processor Trace recording format.
2632 * GDB now allows users to specify explicit locations, bypassing
2633 the linespec parser. This feature is also available to GDB/MI
2636 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2637 GDB now is able to debug both AArch64 applications and ARM applications
2640 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2641 including JIT compiling fast tracepoint's conditional expression bytecode
2644 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2646 * "info threads", "info inferiors", "info display", "info checkpoints"
2647 and "maint info program-spaces" now list the corresponding items in
2648 ascending ID order, for consistency with all other "info" commands.
2650 * In Ada, the overloads selection menu has been enhanced to display the
2651 parameter types and the return types for the matching overloaded subprograms.
2655 maint set target-non-stop (on|off|auto)
2656 maint show target-non-stop
2657 Control whether GDB targets always operate in non-stop mode even if
2658 "set non-stop" is "off". The default is "auto", meaning non-stop
2659 mode is enabled if supported by the target.
2661 maint set bfd-sharing
2662 maint show bfd-sharing
2663 Control the reuse of bfd objects.
2666 show debug bfd-cache
2667 Control display of debugging info regarding bfd caching.
2671 Control display of debugging info regarding FreeBSD threads.
2673 set remote multiprocess-extensions-packet
2674 show remote multiprocess-extensions-packet
2675 Set/show the use of the remote protocol multiprocess extensions.
2677 set remote thread-events
2678 show remote thread-events
2679 Set/show the use of thread create/exit events.
2681 set ada print-signatures on|off
2682 show ada print-signatures"
2683 Control whether parameter types and return types are displayed in overloads
2684 selection menus. It is activated (@code{on}) by default.
2688 Controls the maximum size of memory, in bytes, that GDB will
2689 allocate for value contents. Prevents incorrect programs from
2690 causing GDB to allocate overly large buffers. Default is 64k.
2692 * The "disassemble" command accepts a new modifier: /s.
2693 It prints mixed source+disassembly like /m with two differences:
2694 - disassembled instructions are now printed in program order, and
2695 - and source for all relevant files is now printed.
2696 The "/m" option is now considered deprecated: its "source-centric"
2697 output hasn't proved useful in practice.
2699 * The "record instruction-history" command accepts a new modifier: /s.
2700 It behaves exactly like /m and prints mixed source+disassembly.
2702 * The "set scheduler-locking" command supports a new mode "replay".
2703 It behaves like "off" in record mode and like "on" in replay mode.
2705 * Support for various ROM monitors has been removed:
2707 target dbug dBUG ROM monitor for Motorola ColdFire
2708 target picobug Motorola picobug monitor
2709 target dink32 DINK32 ROM monitor for PowerPC
2710 target m32r Renesas M32R/D ROM monitor
2711 target mon2000 mon2000 ROM monitor
2712 target ppcbug PPCBUG ROM monitor for PowerPC
2714 * Support for reading/writing memory and extracting values on architectures
2715 whose memory is addressable in units of any integral multiple of 8 bits.
2718 Allows to break when an Ada exception is handled.
2720 * New remote packets
2723 Indicates that an exec system call was executed.
2725 exec-events feature in qSupported
2726 The qSupported packet allows GDB to request support for exec
2727 events using the new 'gdbfeature' exec-event, and the qSupported
2728 response can contain the corresponding 'stubfeature'. Set and
2729 show commands can be used to display whether these features are enabled.
2732 Equivalent to interrupting with the ^C character, but works in
2735 thread created stop reason (T05 create:...)
2736 Indicates that the thread was just created and is stopped at entry.
2738 thread exit stop reply (w exitcode;tid)
2739 Indicates that the thread has terminated.
2742 Enables/disables thread create and exit event reporting. For
2743 example, this is used in non-stop mode when GDB stops a set of
2744 threads and synchronously waits for the their corresponding stop
2745 replies. Without exit events, if one of the threads exits, GDB
2746 would hang forever not knowing that it should no longer expect a
2747 stop for that same thread.
2750 Indicates that there are no resumed threads left in the target (all
2751 threads are stopped). The remote stub reports support for this stop
2752 reply to GDB's qSupported query.
2755 Enables/disables catching syscalls from the inferior process.
2756 The remote stub reports support for this packet to GDB's qSupported query.
2758 syscall_entry stop reason
2759 Indicates that a syscall was just called.
2761 syscall_return stop reason
2762 Indicates that a syscall just returned.
2764 * Extended-remote exec events
2766 ** GDB now has support for exec events on extended-remote Linux targets.
2767 For such targets with Linux kernels 2.5.46 and later, this enables
2768 follow-exec-mode and exec catchpoints.
2770 set remote exec-event-feature-packet
2771 show remote exec-event-feature-packet
2772 Set/show the use of the remote exec event feature.
2774 * Thread names in remote protocol
2776 The reply to qXfer:threads:read may now include a name attribute for each
2779 * Target remote mode fork and exec events
2781 ** GDB now has support for fork and exec events on target remote mode
2782 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2783 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2784 fork and exec catchpoints.
2786 * Remote syscall events
2788 ** GDB now has support for catch syscall on remote Linux targets,
2789 currently enabled on x86/x86_64 architectures.
2791 set remote catch-syscall-packet
2792 show remote catch-syscall-packet
2793 Set/show the use of the remote catch syscall feature.
2797 ** The -var-set-format command now accepts the zero-hexadecimal
2798 format. It outputs data in hexadecimal format with zero-padding on the
2803 ** gdb.InferiorThread objects have a new attribute "global_num",
2804 which refers to the thread's global thread ID. The existing
2805 "num" attribute now refers to the thread's per-inferior number.
2806 See "Per-inferior thread numbers" above.
2807 ** gdb.InferiorThread objects have a new attribute "inferior", which
2808 is the Inferior object the thread belongs to.
2810 *** Changes in GDB 7.10
2812 * Support for process record-replay and reverse debugging on aarch64*-linux*
2813 targets has been added. GDB now supports recording of A64 instruction set
2814 including advance SIMD instructions.
2816 * Support for Sun's version of the "stabs" debug file format has been removed.
2818 * GDB now honors the content of the file /proc/PID/coredump_filter
2819 (PID is the process ID) on GNU/Linux systems. This file can be used
2820 to specify the types of memory mappings that will be included in a
2821 corefile. For more information, please refer to the manual page of
2822 "core(5)". GDB also has a new command: "set use-coredump-filter
2823 on|off". It allows to set whether GDB will read the content of the
2824 /proc/PID/coredump_filter file when generating a corefile.
2826 * The "info os" command on GNU/Linux can now display information on
2828 "info os cpus" Listing of all cpus/cores on the system
2830 * GDB has two new commands: "set serial parity odd|even|none" and
2831 "show serial parity". These allows to set or show parity for the
2834 * The "info source" command now displays the producer string if it was
2835 present in the debug info. This typically includes the compiler version
2836 and may include things like its command line arguments.
2838 * The "info dll", an alias of the "info sharedlibrary" command,
2839 is now available on all platforms.
2841 * Directory names supplied to the "set sysroot" commands may be
2842 prefixed with "target:" to tell GDB to access shared libraries from
2843 the target system, be it local or remote. This replaces the prefix
2844 "remote:". The default sysroot has been changed from "" to
2845 "target:". "remote:" is automatically converted to "target:" for
2846 backward compatibility.
2848 * The system root specified by "set sysroot" will be prepended to the
2849 filename of the main executable (if reported to GDB as absolute by
2850 the operating system) when starting processes remotely, and when
2851 attaching to already-running local or remote processes.
2853 * GDB now supports automatic location and retrieval of executable
2854 files from remote targets. Remote debugging can now be initiated
2855 using only a "target remote" or "target extended-remote" command
2856 (no "set sysroot" or "file" commands are required). See "New remote
2859 * The "dump" command now supports verilog hex format.
2861 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2863 * On GNU/Linux, GDB and gdbserver are now able to access executable
2864 and shared library files without a "set sysroot" command when
2865 attaching to processes running in different mount namespaces from
2866 the debugger. This makes it possible to attach to processes in
2867 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2868 See "New remote packets" below.
2870 * The "tui reg" command now provides completion for all of the
2871 available register groups, including target specific groups.
2873 * The HISTSIZE environment variable is no longer read when determining
2874 the size of GDB's command history. GDB now instead reads the dedicated
2875 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2876 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2881 ** Memory ports can now be unbuffered.
2885 ** gdb.Objfile objects have a new attribute "username",
2886 which is the name of the objfile as specified by the user,
2887 without, for example, resolving symlinks.
2888 ** You can now write frame unwinders in Python.
2889 ** gdb.Type objects have a new method "optimized_out",
2890 returning optimized out gdb.Value instance of this type.
2891 ** gdb.Value objects have new methods "reference_value" and
2892 "const_value" which return a reference to the value and a
2893 "const" version of the value respectively.
2897 maint print symbol-cache
2898 Print the contents of the symbol cache.
2900 maint print symbol-cache-statistics
2901 Print statistics of symbol cache usage.
2903 maint flush-symbol-cache
2904 Flush the contents of the symbol cache.
2908 Start branch trace recording using Branch Trace Store (BTS) format.
2911 Evaluate expression by using the compiler and print result.
2915 Explicit commands for enabling and disabling tui mode.
2918 set mpx bound on i386 and amd64
2919 Support for bound table investigation on Intel MPX enabled applications.
2923 Start branch trace recording using Intel Processor Trace format.
2926 Print information about branch tracing internals.
2928 maint btrace packet-history
2929 Print the raw branch tracing data.
2931 maint btrace clear-packet-history
2932 Discard the stored raw branch tracing data.
2935 Discard all branch tracing data. It will be fetched and processed
2936 anew by the next "record" command.
2941 Renamed from "set debug dwarf2-die".
2942 show debug dwarf-die
2943 Renamed from "show debug dwarf2-die".
2945 set debug dwarf-read
2946 Renamed from "set debug dwarf2-read".
2947 show debug dwarf-read
2948 Renamed from "show debug dwarf2-read".
2950 maint set dwarf always-disassemble
2951 Renamed from "maint set dwarf2 always-disassemble".
2952 maint show dwarf always-disassemble
2953 Renamed from "maint show dwarf2 always-disassemble".
2955 maint set dwarf max-cache-age
2956 Renamed from "maint set dwarf2 max-cache-age".
2957 maint show dwarf max-cache-age
2958 Renamed from "maint show dwarf2 max-cache-age".
2960 set debug dwarf-line
2961 show debug dwarf-line
2962 Control display of debugging info regarding DWARF line processing.
2965 show max-completions
2966 Set the maximum number of candidates to be considered during
2967 completion. The default value is 200. This limit allows GDB
2968 to avoid generating large completion lists, the computation of
2969 which can cause the debugger to become temporarily unresponsive.
2971 set history remove-duplicates
2972 show history remove-duplicates
2973 Control the removal of duplicate history entries.
2975 maint set symbol-cache-size
2976 maint show symbol-cache-size
2977 Control the size of the symbol cache.
2979 set|show record btrace bts buffer-size
2980 Set and show the size of the ring buffer used for branch tracing in
2982 The obtained size may differ from the requested size. Use "info
2983 record" to see the obtained buffer size.
2985 set debug linux-namespaces
2986 show debug linux-namespaces
2987 Control display of debugging info regarding Linux namespaces.
2989 set|show record btrace pt buffer-size
2990 Set and show the size of the ring buffer used for branch tracing in
2991 Intel Processor Trace format.
2992 The obtained size may differ from the requested size. Use "info
2993 record" to see the obtained buffer size.
2995 maint set|show btrace pt skip-pad
2996 Set and show whether PAD packets are skipped when computing the
2999 * The command 'thread apply all' can now support new option '-ascending'
3000 to call its specified command for all threads in ascending order.
3002 * Python/Guile scripting
3004 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3005 special section named `.debug_gdb_scripts'.
3007 * New remote packets
3009 qXfer:btrace-conf:read
3010 Return the branch trace configuration for the current thread.
3012 Qbtrace-conf:bts:size
3013 Set the requested ring buffer size for branch tracing in BTS format.
3016 Enable Intel Processor Trace-based branch tracing for the current
3017 process. The remote stub reports support for this packet to GDB's
3020 Qbtrace-conf:pt:size
3021 Set the requested ring buffer size for branch tracing in Intel Processor
3025 Indicates a memory breakpoint instruction was executed, irrespective
3026 of whether it was GDB that planted the breakpoint or the breakpoint
3027 is hardcoded in the program. This is required for correct non-stop
3031 Indicates the target stopped for a hardware breakpoint. This is
3032 required for correct non-stop mode operation.
3035 Return information about files on the remote system.
3037 qXfer:exec-file:read
3038 Return the full absolute name of the file that was executed to
3039 create a process running on the remote system.
3042 Select the filesystem on which vFile: operations with filename
3043 arguments will operate. This is required for GDB to be able to
3044 access files on remote targets where the remote stub does not
3045 share a common filesystem with the inferior(s).
3048 Indicates that a fork system call was executed.
3051 Indicates that a vfork system call was executed.
3053 vforkdone stop reason
3054 Indicates that a vfork child of the specified process has executed
3055 an exec or exit, allowing the vfork parent to resume execution.
3057 fork-events and vfork-events features in qSupported
3058 The qSupported packet allows GDB to request support for fork and
3059 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3060 and the qSupported response can contain the corresponding
3061 'stubfeatures'. Set and show commands can be used to display
3062 whether these features are enabled.
3064 * Extended-remote fork events
3066 ** GDB now has support for fork events on extended-remote Linux
3067 targets. For targets with Linux kernels 2.5.60 and later, this
3068 enables follow-fork-mode and detach-on-fork for both fork and
3069 vfork, as well as fork and vfork catchpoints.
3071 * The info record command now shows the recording format and the
3072 branch tracing configuration for the current thread when using
3073 the btrace record target.
3074 For the BTS format, it shows the ring buffer size.
3076 * GDB now has support for DTrace USDT (Userland Static Defined
3077 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3079 * GDB now supports access to vector registers on S/390 GNU/Linux
3082 * Removed command line options
3084 -xdb HP-UX XDB compatibility mode.
3086 * Removed targets and native configurations
3088 HP/PA running HP-UX hppa*-*-hpux*
3089 Itanium running HP-UX ia64-*-hpux*
3091 * New configure options
3094 This configure option allows the user to build GDB with support for
3095 Intel Processor Trace (default: auto). This requires libipt.
3097 --with-libipt-prefix=PATH
3098 Specify the path to the version of libipt that GDB should use.
3099 $PATH/include should contain the intel-pt.h header and
3100 $PATH/lib should contain the libipt.so library.
3102 *** Changes in GDB 7.9.1
3106 ** Xmethods can now specify a result type.
3108 *** Changes in GDB 7.9
3110 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3114 ** You can now access frame registers from Python scripts.
3115 ** New attribute 'producer' for gdb.Symtab objects.
3116 ** gdb.Objfile objects have a new attribute "progspace",
3117 which is the gdb.Progspace object of the containing program space.
3118 ** gdb.Objfile objects have a new attribute "owner".
3119 ** gdb.Objfile objects have a new attribute "build_id",
3120 which is the build ID generated when the file was built.
3121 ** gdb.Objfile objects have a new method "add_separate_debug_file".
3122 ** A new event "gdb.clear_objfiles" has been added, triggered when
3123 selecting a new file to debug.
3124 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3125 ** New function gdb.lookup_objfile.
3127 New events which are triggered when GDB modifies the state of the
3130 ** gdb.events.inferior_call_pre: Function call is about to be made.
3131 ** gdb.events.inferior_call_post: Function call has just been made.
3132 ** gdb.events.memory_changed: A memory location has been altered.
3133 ** gdb.events.register_changed: A register has been altered.
3135 * New Python-based convenience functions:
3137 ** $_caller_is(name [, number_of_frames])
3138 ** $_caller_matches(regexp [, number_of_frames])
3139 ** $_any_caller_is(name [, number_of_frames])
3140 ** $_any_caller_matches(regexp [, number_of_frames])
3142 * GDB now supports the compilation and injection of source code into
3143 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
3144 to compile the source code to object code, and if successful, inject
3145 and execute that code within the current context of the inferior.
3146 Currently the C language is supported. The commands used to
3147 interface with this new feature are:
3149 compile code [-raw|-r] [--] [source code]
3150 compile file [-raw|-r] filename
3154 demangle [-l language] [--] name
3155 Demangle "name" in the specified language, or the current language
3156 if elided. This command is renamed from the "maint demangle" command.
3157 The latter is kept as a no-op to avoid "maint demangle" being interpreted
3158 as "maint demangler-warning".
3160 queue-signal signal-name-or-number
3161 Queue a signal to be delivered to the thread when it is resumed.
3163 add-auto-load-scripts-directory directory
3164 Add entries to the list of directories from which to load auto-loaded
3167 maint print user-registers
3168 List all currently available "user" registers.
3170 compile code [-r|-raw] [--] [source code]
3171 Compile, inject, and execute in the inferior the executable object
3172 code produced by compiling the provided source code.
3174 compile file [-r|-raw] filename
3175 Compile and inject into the inferior the executable object code
3176 produced by compiling the source code stored in the filename
3179 * On resume, GDB now always passes the signal the program had stopped
3180 for to the thread the signal was sent to, even if the user changed
3181 threads before resuming. Previously GDB would often (but not
3182 always) deliver the signal to the thread that happens to be current
3185 * Conversely, the "signal" command now consistently delivers the
3186 requested signal to the current thread. GDB now asks for
3187 confirmation if the program had stopped for a signal and the user
3188 switched threads meanwhile.
3190 * "breakpoint always-inserted" modes "off" and "auto" merged.
3192 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3193 won't remove breakpoints from the target until all threads stop,
3194 even in non-stop mode. The "auto" mode has been removed, and "off"
3195 is now the default mode.
3199 set debug symbol-lookup
3200 show debug symbol-lookup
3201 Control display of debugging info regarding symbol lookup.
3205 ** The -list-thread-groups command outputs an exit-code field for
3206 inferiors that have exited.
3210 MIPS SDE mips*-sde*-elf*
3214 Support for these obsolete configurations has been removed.
3216 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
3217 SGI Irix-5.x mips-*-irix5*
3218 SGI Irix-6.x mips-*-irix6*
3219 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
3220 VAX running Ultrix vax-*-ultrix*
3222 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3223 and "assf"), have been removed. Use the "sharedlibrary" command, or
3224 its alias "share", instead.
3226 *** Changes in GDB 7.8
3228 * New command line options
3231 This is an alias for the --data-directory option.
3233 * GDB supports printing and modifying of variable length automatic arrays
3234 as specified in ISO C99.
3236 * The ARM simulator now supports instruction level tracing
3237 with or without disassembly.
3241 GDB now has support for scripting using Guile. Whether this is
3242 available is determined at configure time.
3243 Guile version 2.0 or greater is required.
3244 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3246 * New commands (for set/show, see "New options" below)
3250 Invoke CODE by passing it to the Guile interpreter.
3254 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3256 info auto-load guile-scripts [regexp]
3257 Print the list of automatically loaded Guile scripts.
3259 * The source command is now capable of sourcing Guile scripts.
3260 This feature is dependent on the debugger being built with Guile support.
3264 set print symbol-loading (off|brief|full)
3265 show print symbol-loading
3266 Control whether to print informational messages when loading symbol
3267 information for a file. The default is "full", but when debugging
3268 programs with large numbers of shared libraries the amount of output
3269 becomes less useful.
3271 set guile print-stack (none|message|full)
3272 show guile print-stack
3273 Show a stack trace when an error is encountered in a Guile script.
3275 set auto-load guile-scripts (on|off)
3276 show auto-load guile-scripts
3277 Control auto-loading of Guile script files.
3279 maint ada set ignore-descriptive-types (on|off)
3280 maint ada show ignore-descriptive-types
3281 Control whether the debugger should ignore descriptive types in Ada
3282 programs. The default is not to ignore the descriptive types. See
3283 the user manual for more details on descriptive types and the intended
3284 usage of this option.
3286 set auto-connect-native-target
3288 Control whether GDB is allowed to automatically connect to the
3289 native target for the run, attach, etc. commands when not connected
3290 to any target yet. See also "target native" below.
3292 set record btrace replay-memory-access (read-only|read-write)
3293 show record btrace replay-memory-access
3294 Control what memory accesses are allowed during replay.
3296 maint set target-async (on|off)
3297 maint show target-async
3298 This controls whether GDB targets operate in synchronous or
3299 asynchronous mode. Normally the default is asynchronous, if it is
3300 available; but this can be changed to more easily debug problems
3301 occurring only in synchronous mode.
3303 set mi-async (on|off)
3305 Control whether MI asynchronous mode is preferred. This supersedes
3306 "set target-async" of previous GDB versions.
3308 * "set target-async" is deprecated as a CLI option and is now an alias
3309 for "set mi-async" (only puts MI into async mode).
3311 * Background execution commands (e.g., "c&", "s&", etc.) are now
3312 possible ``out of the box'' if the target supports them. Previously
3313 the user would need to explicitly enable the possibility with the
3314 "set target-async on" command.
3316 * New features in the GDB remote stub, GDBserver
3318 ** New option --debug-format=option1[,option2,...] allows one to add
3319 additional text to each output. At present only timestamps
3320 are supported: --debug-format=timestamps.
3321 Timestamps can also be turned on with the
3322 "monitor set debug-format timestamps" command from GDB.
3324 * The 'record instruction-history' command now starts counting instructions
3325 at one. This also affects the instruction ranges reported by the
3326 'record function-call-history' command when given the /i modifier.
3328 * The command 'record function-call-history' supports a new modifier '/c' to
3329 indent the function names based on their call stack depth.
3330 The fields for the '/i' and '/l' modifier have been reordered.
3331 The source line range is now prefixed with 'at'.
3332 The instruction range is now prefixed with 'inst'.
3333 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3334 "record instruction-history" and "list" commands.
3336 * The ranges given as arguments to the 'record function-call-history' and
3337 'record instruction-history' commands are now inclusive.
3339 * The btrace record target now supports the 'record goto' command.
3340 For locations inside the execution trace, the back trace is computed
3341 based on the information stored in the execution trace.
3343 * The btrace record target supports limited reverse execution and replay.
3344 The target does not record data and therefore does not allow reading
3345 memory or registers.
3347 * The "catch syscall" command now works on s390*-linux* targets.
3349 * The "compare-sections" command is no longer specific to target
3350 remote. It now works with all targets.
3352 * All native targets are now consistently called "native".
3353 Consequently, the "target child", "target GNU", "target djgpp",
3354 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3355 commands have been replaced with "target native". The QNX/NTO port
3356 leaves the "procfs" target in place and adds a "native" target for
3357 consistency with other ports. The impact on users should be minimal
3358 as these commands previously either throwed an error, or were
3359 no-ops. The target's name is visible in the output of the following
3360 commands: "help target", "info target", "info files", "maint print
3363 * The "target native" command now connects to the native target. This
3364 can be used to launch native programs even when "set
3365 auto-connect-native-target" is set to off.
3367 * GDB now supports access to Intel MPX registers on GNU/Linux.
3369 * Support for Intel AVX-512 registers on GNU/Linux.
3370 Support displaying and modifying Intel AVX-512 registers
3371 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3373 * New remote packets
3375 qXfer:btrace:read's annex
3376 The qXfer:btrace:read packet supports a new annex 'delta' to read
3377 branch trace incrementally.
3381 ** Valid Python operations on gdb.Value objects representing
3382 structs/classes invoke the corresponding overloaded operators if
3384 ** New `Xmethods' feature in the Python API. Xmethods are
3385 additional methods or replacements for existing methods of a C++
3386 class. This feature is useful for those cases where a method
3387 defined in C++ source code could be inlined or optimized out by
3388 the compiler, making it unavailable to GDB.
3391 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3393 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3394 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3395 its alias "share", instead.
3397 * The commands "set remotebaud" and "show remotebaud" are no longer
3398 supported. Use "set serial baud" and "show serial baud" (respectively)
3403 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3404 target-async". The latter is left as a deprecated alias of the
3405 former for backward compatibility. If the target supports it,
3406 CLI background execution commands are now always possible by
3407 default, independently of whether the frontend stated a
3408 preference for asynchronous execution with "-gdb-set mi-async".
3409 Previously "-gdb-set target-async off" affected both MI execution
3410 commands and CLI execution commands.
3412 *** Changes in GDB 7.7
3414 * Improved support for process record-replay and reverse debugging on
3415 arm*-linux* targets. Support for thumb32 and syscall instruction
3416 recording has been added.
3418 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3420 * GDB now supports Fission DWP file format version 2.
3421 http://gcc.gnu.org/wiki/DebugFission
3423 * New convenience function "$_isvoid", to check whether an expression
3424 is void. A void expression is an expression where the type of the
3425 result is "void". For example, some convenience variables may be
3426 "void" when evaluated (e.g., "$_exitcode" before the execution of
3427 the program being debugged; or an undefined convenience variable).
3428 Another example, when calling a function whose return type is
3431 * The "maintenance print objfiles" command now takes an optional regexp.
3433 * The "catch syscall" command now works on arm*-linux* targets.
3435 * GDB now consistently shows "<not saved>" when printing values of
3436 registers the debug info indicates have not been saved in the frame
3437 and there's nowhere to retrieve them from
3438 (callee-saved/call-clobbered registers):
3443 (gdb) info registers rax
3446 Before, the former would print "<optimized out>", and the latter
3447 "*value not available*".
3449 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3454 ** Frame filters and frame decorators have been added.
3455 ** Temporary breakpoints are now supported.
3456 ** Line tables representation has been added.
3457 ** New attribute 'parent_type' for gdb.Field objects.
3458 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3459 ** New attribute 'name' for gdb.Type objects.
3463 Nios II ELF nios2*-*-elf
3464 Nios II GNU/Linux nios2*-*-linux
3465 Texas Instruments MSP430 msp430*-*-elf
3467 * Removed native configurations
3469 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3470 been removed. ELF variants of these configurations are kept supported.
3472 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3473 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3474 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3475 i[34567]86-*-openbsd3.[0-3]
3476 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3477 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3478 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3482 Like "catch throw", but catches a re-thrown exception.
3483 maint check-psymtabs
3484 Renamed from old "maint check-symtabs".
3486 Perform consistency checks on symtabs.
3487 maint expand-symtabs
3488 Expand symtabs matching an optional regexp.
3491 Display the details of GDB configure-time options.
3493 maint set|show per-command
3494 maint set|show per-command space
3495 maint set|show per-command time
3496 maint set|show per-command symtab
3497 Enable display of per-command gdb resource usage.
3499 remove-symbol-file FILENAME
3500 remove-symbol-file -a ADDRESS
3501 Remove a symbol file added via add-symbol-file. The file to remove
3502 can be identified by its filename or by an address that lies within
3503 the boundaries of this symbol file in memory.
3506 info exceptions REGEXP
3507 Display the list of Ada exceptions defined in the program being
3508 debugged. If provided, only the exceptions whose names match REGEXP
3513 set debug symfile off|on
3515 Control display of debugging info regarding reading symbol files and
3516 symbol tables within those files
3518 set print raw frame-arguments
3519 show print raw frame-arguments
3520 Set/show whether to print frame arguments in raw mode,
3521 disregarding any defined pretty-printers.
3523 set remote trace-status-packet
3524 show remote trace-status-packet
3525 Set/show the use of remote protocol qTStatus packet.
3529 Control display of debugging messages related to Nios II targets.
3533 Control whether target-assisted range stepping is enabled.
3535 set startup-with-shell
3536 show startup-with-shell
3537 Specifies whether Unix child processes are started via a shell or
3542 Use the target memory cache for accesses to the code segment. This
3543 improves performance of remote debugging (particularly disassembly).
3545 * You can now use a literal value 'unlimited' for options that
3546 interpret 0 or -1 as meaning "unlimited". E.g., "set
3547 trace-buffer-size unlimited" is now an alias for "set
3548 trace-buffer-size -1" and "set height unlimited" is now an alias for
3551 * The "set debug symtab-create" debugging option of GDB has been changed to
3552 accept a verbosity level. 0 means "off", 1 provides basic debugging
3553 output, and values of 2 or greater provides more verbose output.
3555 * New command-line options
3557 Display the details of GDB configure-time options.
3559 * The command 'tsave' can now support new option '-ctf' to save trace
3560 buffer in Common Trace Format.
3562 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3565 * GDB now implements the C++ 'typeid' operator.
3567 * The new convenience variable $_exception holds the exception being
3568 thrown or caught at an exception-related catchpoint.
3570 * The exception-related catchpoints, like "catch throw", now accept a
3571 regular expression which can be used to filter exceptions by type.
3573 * The new convenience variable $_exitsignal is automatically set to
3574 the terminating signal number when the program being debugged dies
3575 due to an uncaught signal.
3579 ** All MI commands now accept an optional "--language" option.
3580 Support for this feature can be verified by using the "-list-features"
3581 command, which should contain "language-option".
3583 ** The new command -info-gdb-mi-command allows the user to determine
3584 whether a GDB/MI command is supported or not.
3586 ** The "^error" result record returned when trying to execute an undefined
3587 GDB/MI command now provides a variable named "code" whose content is the
3588 "undefined-command" error code. Support for this feature can be verified
3589 by using the "-list-features" command, which should contain
3590 "undefined-command-error-code".
3592 ** The -trace-save MI command can optionally save trace buffer in Common
3595 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3597 ** The command -data-list-register-values now accepts an optional
3598 "--skip-unavailable" option. When used, only the available registers
3601 ** The new command -trace-frame-collected dumps collected variables,
3602 computed expressions, tvars, memory and registers in a traceframe.
3604 ** The commands -stack-list-locals, -stack-list-arguments and
3605 -stack-list-variables now accept an option "--skip-unavailable".
3606 When used, only the available locals or arguments are displayed.
3608 ** The -exec-run command now accepts an optional "--start" option.
3609 When used, the command follows the same semantics as the "start"
3610 command, stopping the program's execution at the start of its
3611 main subprogram. Support for this feature can be verified using
3612 the "-list-features" command, which should contain
3613 "exec-run-start-option".
3615 ** The new commands -catch-assert and -catch-exceptions insert
3616 catchpoints stopping the program when Ada exceptions are raised.
3618 ** The new command -info-ada-exceptions provides the equivalent of
3619 the new "info exceptions" command.
3621 * New system-wide configuration scripts
3622 A GDB installation now provides scripts suitable for use as system-wide
3623 configuration scripts for the following systems:
3627 * GDB now supports target-assigned range stepping with remote targets.
3628 This improves the performance of stepping source lines by reducing
3629 the number of control packets from/to GDB. See "New remote packets"
3632 * GDB now understands the element 'tvar' in the XML traceframe info.
3633 It has the id of the collected trace state variables.
3635 * On S/390 targets that provide the transactional-execution feature,
3636 the program interruption transaction diagnostic block (TDB) is now
3637 represented as a number of additional "registers" in GDB.
3639 * New remote packets
3643 The vCont packet supports a new 'r' action, that tells the remote
3644 stub to step through an address range itself, without GDB
3645 involvemement at each single-step.
3647 qXfer:libraries-svr4:read's annex
3648 The previously unused annex of the qXfer:libraries-svr4:read packet
3649 is now used to support passing an argument list. The remote stub
3650 reports support for this argument list to GDB's qSupported query.
3651 The defined arguments are "start" and "prev", used to reduce work
3652 necessary for library list updating, resulting in significant
3655 * New features in the GDB remote stub, GDBserver
3657 ** GDBserver now supports target-assisted range stepping. Currently
3658 enabled on x86/x86_64 GNU/Linux targets.
3660 ** GDBserver now adds element 'tvar' in the XML in the reply to
3661 'qXfer:traceframe-info:read'. It has the id of the collected
3662 trace state variables.
3664 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3667 * New 'z' formatter for printing and examining memory, this displays the
3668 value as hexadecimal zero padded on the left to the size of the type.
3670 * GDB can now use Windows x64 unwinding data.
3672 * The "set remotebaud" command has been replaced by "set serial baud".
3673 Similarly, "show remotebaud" has been replaced by "show serial baud".
3674 The "set remotebaud" and "show remotebaud" commands are still available
3675 to provide backward compatibility with older versions of GDB.
3677 *** Changes in GDB 7.6
3679 * Target record has been renamed to record-full.
3680 Record/replay is now enabled with the "record full" command.
3681 This also affects settings that are associated with full record/replay
3682 that have been moved from "set/show record" to "set/show record full":
3684 set|show record full insn-number-max
3685 set|show record full stop-at-limit
3686 set|show record full memory-query
3688 * A new record target "record-btrace" has been added. The new target
3689 uses hardware support to record the control-flow of a process. It
3690 does not support replaying the execution, but it implements the
3691 below new commands for investigating the recorded execution log.
3692 This new recording method can be enabled using:
3696 The "record-btrace" target is only available on Intel Atom processors
3697 and requires a Linux kernel 2.6.32 or later.
3699 * Two new commands have been added for record/replay to give information
3700 about the recorded execution without having to replay the execution.
3701 The commands are only supported by "record btrace".
3703 record instruction-history prints the execution history at
3704 instruction granularity
3706 record function-call-history prints the execution history at
3707 function granularity
3709 * New native configurations
3711 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3712 FreeBSD/powerpc powerpc*-*-freebsd
3713 x86_64/Cygwin x86_64-*-cygwin*
3714 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3718 ARM AArch64 aarch64*-*-elf
3719 ARM AArch64 GNU/Linux aarch64*-*-linux
3720 Lynx 178 PowerPC powerpc-*-lynx*178
3721 x86_64/Cygwin x86_64-*-cygwin*
3722 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3724 * If the configured location of system.gdbinit file (as given by the
3725 --with-system-gdbinit option at configure time) is in the
3726 data-directory (as specified by --with-gdb-datadir at configure
3727 time) or in one of its subdirectories, then GDB will look for the
3728 system-wide init file in the directory specified by the
3729 --data-directory command-line option.
3731 * New command line options:
3733 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3734 other initialization files, unlike -nx which disables all of them.
3736 * Removed command line options
3738 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3741 * The 'ptype' and 'whatis' commands now accept an argument to control
3744 * 'info proc' now works on some core files.
3748 ** Vectors can be created with gdb.Type.vector.
3750 ** Python's atexit.register now works in GDB.
3752 ** Types can be pretty-printed via a Python API.
3754 ** Python 3 is now supported (in addition to Python 2.4 or later)
3756 ** New class gdb.Architecture exposes GDB's internal representation
3757 of architecture in the Python API.
3759 ** New method Frame.architecture returns the gdb.Architecture object
3760 corresponding to the frame's architecture.
3762 * New Python-based convenience functions:
3764 ** $_memeq(buf1, buf2, length)
3765 ** $_streq(str1, str2)
3767 ** $_regex(str, regex)
3769 * The 'cd' command now defaults to using '~' (the home directory) if not
3772 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3773 default for GCC since November 2000.
3775 * The command 'forward-search' can now be abbreviated as 'fo'.
3777 * The command 'info tracepoints' can now display 'installed on target'
3778 or 'not installed on target' for each non-pending location of tracepoint.
3780 * New configure options
3782 --enable-libmcheck/--disable-libmcheck
3783 By default, development versions are built with -lmcheck on hosts
3784 that support it, in order to help track memory corruption issues.
3785 Release versions, on the other hand, are built without -lmcheck
3786 by default. The --enable-libmcheck/--disable-libmcheck configure
3787 options allow the user to override that default.
3788 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3789 This configure option allows the user to build GDB with
3790 libbabeltrace using which GDB can read Common Trace Format data.
3792 * New commands (for set/show, see "New options" below)
3795 Catch signals. This is similar to "handle", but allows commands and
3796 conditions to be attached.
3799 List the BFDs known to GDB.
3801 python-interactive [command]
3803 Start a Python interactive prompt, or evaluate the optional command
3804 and print the result of expressions.
3807 "py" is a new alias for "python".
3809 enable type-printer [name]...
3810 disable type-printer [name]...
3811 Enable or disable type printers.
3815 ** For the Renesas Super-H architecture, the "regs" command has been removed
3816 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3821 set print type methods (on|off)
3822 show print type methods
3823 Control whether method declarations are displayed by "ptype".
3824 The default is to show them.
3826 set print type typedefs (on|off)
3827 show print type typedefs
3828 Control whether typedef definitions are displayed by "ptype".
3829 The default is to show them.
3831 set filename-display basename|relative|absolute
3832 show filename-display
3833 Control the way in which filenames is displayed.
3834 The default is "relative", which preserves previous behavior.
3836 set trace-buffer-size
3837 show trace-buffer-size
3838 Request target to change the size of trace buffer.
3840 set remote trace-buffer-size-packet auto|on|off
3841 show remote trace-buffer-size-packet
3842 Control the use of the remote protocol `QTBuffer:size' packet.
3846 Control display of debugging messages related to ARM AArch64.
3849 set debug coff-pe-read
3850 show debug coff-pe-read
3851 Control display of debugging messages related to reading of COFF/PE
3856 Control display of debugging messages related to Mach-O symbols
3859 set debug notification
3860 show debug notification
3861 Control display of debugging info for async remote notification.
3865 ** Command parameter changes are now notified using new async record
3866 "=cmd-param-changed".
3867 ** Trace frame changes caused by command "tfind" are now notified using
3868 new async record "=traceframe-changed".
3869 ** The creation, deletion and modification of trace state variables
3870 are now notified using new async records "=tsv-created",
3871 "=tsv-deleted" and "=tsv-modified".
3872 ** The start and stop of process record are now notified using new
3873 async record "=record-started" and "=record-stopped".
3874 ** Memory changes are now notified using new async record
3876 ** The data-disassemble command response will include a "fullname" field
3877 containing the absolute file name when source has been requested.
3878 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3879 command, to allow pattern filling of memory areas.
3880 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3881 library load/unload events.
3882 ** The response to breakpoint commands and breakpoint async records
3883 includes an "installed" field containing a boolean state about each
3884 non-pending tracepoint location is whether installed on target or not.
3885 ** Output of the "-trace-status" command includes a "trace-file" field
3886 containing the name of the trace file being examined. This field is
3887 optional, and only present when examining a trace file.
3888 ** The "fullname" field is now always present along with the "file" field,
3889 even if the file cannot be found by GDB.
3891 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
3892 You must have the LZMA library available when configuring GDB for this
3893 feature to be enabled. For more information, see:
3894 http://fedoraproject.org/wiki/Features/MiniDebugInfo
3896 * New remote packets
3899 Set the size of trace buffer. The remote stub reports support for this
3900 packet to gdb's qSupported query.
3903 Enable Branch Trace Store (BTS)-based branch tracing for the current
3904 thread. The remote stub reports support for this packet to gdb's
3908 Disable branch tracing for the current thread. The remote stub reports
3909 support for this packet to gdb's qSupported query.
3912 Read the traced branches for the current thread. The remote stub
3913 reports support for this packet to gdb's qSupported query.
3915 *** Changes in GDB 7.5
3917 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
3918 for more x32 ABI info.
3920 * GDB now supports access to MIPS DSP registers on Linux targets.
3922 * GDB now supports debugging microMIPS binaries.
3924 * The "info os" command on GNU/Linux can now display information on
3925 several new classes of objects managed by the operating system:
3926 "info os procgroups" lists process groups
3927 "info os files" lists file descriptors
3928 "info os sockets" lists internet-domain sockets
3929 "info os shm" lists shared-memory regions
3930 "info os semaphores" lists semaphores
3931 "info os msg" lists message queues
3932 "info os modules" lists loaded kernel modules
3934 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
3935 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
3936 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
3937 options and inspect the probe arguments using the new $_probe_arg family
3938 of convenience variables. You can obtain more information about SystemTap
3939 in <http://sourceware.org/systemtap/>.
3941 * GDB now supports reversible debugging on ARM, it allows you to
3942 debug basic ARM and THUMB instructions, and provides
3943 record/replay support.
3945 * The option "symbol-reloading" has been deleted as it is no longer used.
3949 ** GDB commands implemented in Python can now be put in command class
3952 ** The "maint set python print-stack on|off" is now deleted.
3954 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
3955 apply "flag enum"-style pretty-printing to any enum.
3957 ** gdb.lookup_symbol can now work when there is no current frame.
3959 ** gdb.Symbol now has a 'line' attribute, holding the line number in
3960 the source at which the symbol was defined.
3962 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
3963 method 'value'. The former indicates whether the symbol needs a
3964 frame in order to compute its value, and the latter computes the
3967 ** A new method 'referenced_value' on gdb.Value objects which can
3968 dereference pointer as well as C++ reference values.
3970 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
3971 which return the global and static blocks (as gdb.Block objects),
3972 of the underlying symbol table, respectively.
3974 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
3975 object associated with a PC value.
3977 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
3978 of the address range occupied by code for the current source line.
3980 * Go language support.
3981 GDB now supports debugging programs written in the Go programming
3984 * GDBserver now supports stdio connections.
3985 E.g. (gdb) target remote | ssh myhost gdbserver - hello
3987 * The binary "gdbtui" can no longer be built or installed.
3988 Use "gdb -tui" instead.
3990 * GDB will now print "flag" enums specially. A flag enum is one where
3991 all the enumerator values have no bits in common when pairwise
3992 "and"ed. When printing a value whose type is a flag enum, GDB will
3993 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
3994 (gdb) print (enum E) 3
3997 * The filename part of a linespec will now match trailing components
3998 of a source file name. For example, "break gcc/expr.c:1000" will
3999 now set a breakpoint in build/gcc/expr.c, but not
4000 build/libcpp/expr.c.
4002 * The "info proc" and "generate-core-file" commands will now also
4003 work on remote targets connected to GDBserver on Linux.
4005 * The command "info catch" has been removed. It has been disabled
4006 since December 2007.
4008 * The "catch exception" and "catch assert" commands now accept
4009 a condition at the end of the command, much like the "break"
4010 command does. For instance:
4012 (gdb) catch exception Constraint_Error if Barrier = True
4014 Previously, it was possible to add a condition to such catchpoints,
4015 but it had to be done as a second step, after the catchpoint had been
4016 created, using the "condition" command.
4018 * The "info static-tracepoint-marker" command will now also work on
4019 native Linux targets with in-process agent.
4021 * GDB can now set breakpoints on inlined functions.
4023 * The .gdb_index section has been updated to include symbols for
4024 inlined functions. GDB will ignore older .gdb_index sections by
4025 default, which could cause symbol files to be loaded more slowly
4026 until their .gdb_index sections can be recreated. The new command
4027 "set use-deprecated-index-sections on" will cause GDB to use any older
4028 .gdb_index sections it finds. This will restore performance, but the
4029 ability to set breakpoints on inlined functions will be lost in symbol
4030 files with older .gdb_index sections.
4032 The .gdb_index section has also been updated to record more information
4033 about each symbol. This speeds up the "info variables", "info functions"
4034 and "info types" commands when used with programs having the .gdb_index
4035 section, as well as speeding up debugging with shared libraries using
4036 the .gdb_index section.
4038 * Ada support for GDB/MI Variable Objects has been added.
4040 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4045 ** New command -info-os is the MI equivalent of "info os".
4047 ** Output logs ("set logging" and related) now include MI output.
4051 ** "set use-deprecated-index-sections on|off"
4052 "show use-deprecated-index-sections on|off"
4053 Controls the use of deprecated .gdb_index sections.
4055 ** "catch load" and "catch unload" can be used to stop when a shared
4056 library is loaded or unloaded, respectively.
4058 ** "enable count" can be used to auto-disable a breakpoint after
4061 ** "info vtbl" can be used to show the virtual method tables for
4062 C++ and Java objects.
4064 ** "explore" and its sub commands "explore value" and "explore type"
4065 can be used to recursively explore values and types of
4066 expressions. These commands are available only if GDB is
4067 configured with '--with-python'.
4069 ** "info auto-load" shows status of all kinds of auto-loaded files,
4070 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4071 sequences of commands files, "info auto-load python-scripts"
4072 shows status of auto-loading Python script files,
4073 "info auto-load local-gdbinit" shows status of loading init file
4074 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4075 status of inferior specific thread debugging shared library loading.
4077 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4078 and "show auto-load-scripts" commands have been deprecated, use their
4079 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4080 and "show auto-load python-scripts" counterparts instead.
4082 ** "dprintf location,format,args..." creates a dynamic printf, which
4083 is basically a breakpoint that does a printf and immediately
4084 resumes your program's execution, so it is like a printf that you
4085 can insert dynamically at runtime instead of at compiletime.
4087 ** "set print symbol"
4089 Controls whether GDB attempts to display the symbol, if any,
4090 corresponding to addresses it prints. This defaults to "on", but
4091 you can set it to "off" to restore GDB's previous behavior.
4093 * Deprecated commands
4095 ** For the Renesas Super-H architecture, the "regs" command has been
4096 deprecated, and "info all-registers" should be used instead.
4100 Renesas RL78 rl78-*-elf
4101 HP OpenVMS ia64 ia64-hp-openvms*
4103 * GDBserver supports evaluation of breakpoint conditions. When
4104 support is advertised by GDBserver, GDB may be told to send the
4105 breakpoint conditions in bytecode form to GDBserver. GDBserver
4106 will only report the breakpoint trigger to GDB when its condition
4111 set mips compression
4112 show mips compression
4113 Select the compressed ISA encoding used in functions that have no symbol
4114 information available. The encoding can be set to either of:
4117 and is updated automatically from ELF file flags if available.
4119 set breakpoint condition-evaluation
4120 show breakpoint condition-evaluation
4121 Control whether breakpoint conditions are evaluated by GDB ("host") or by
4122 GDBserver ("target"). Default option "auto" chooses the most efficient
4124 This option can improve debugger efficiency depending on the speed of the
4128 Disable auto-loading globally.
4131 Show auto-loading setting of all kinds of auto-loaded files.
4133 set auto-load gdb-scripts on|off
4134 show auto-load gdb-scripts
4135 Control auto-loading of GDB canned sequences of commands files.
4137 set auto-load python-scripts on|off
4138 show auto-load python-scripts
4139 Control auto-loading of Python script files.
4141 set auto-load local-gdbinit on|off
4142 show auto-load local-gdbinit
4143 Control loading of init file (.gdbinit) from current directory.
4145 set auto-load libthread-db on|off
4146 show auto-load libthread-db
4147 Control auto-loading of inferior specific thread debugging shared library.
4149 set auto-load scripts-directory <dir1>[:<dir2>...]
4150 show auto-load scripts-directory
4151 Set a list of directories from which to load auto-loaded scripts.
4152 Automatically loaded Python scripts and GDB scripts are located in one
4153 of the directories listed by this option.
4154 The delimiter (':' above) may differ according to the host platform.
4156 set auto-load safe-path <dir1>[:<dir2>...]
4157 show auto-load safe-path
4158 Set a list of directories from which it is safe to auto-load files.
4159 The delimiter (':' above) may differ according to the host platform.
4161 set debug auto-load on|off
4162 show debug auto-load
4163 Control display of debugging info for auto-loading the files above.
4165 set dprintf-style gdb|call|agent
4167 Control the way in which a dynamic printf is performed; "gdb"
4168 requests a GDB printf command, while "call" causes dprintf to call a
4169 function in the inferior. "agent" requests that the target agent
4170 (such as GDBserver) do the printing.
4172 set dprintf-function <expr>
4173 show dprintf-function
4174 set dprintf-channel <expr>
4175 show dprintf-channel
4176 Set the function and optional first argument to the call when using
4177 the "call" style of dynamic printf.
4179 set disconnected-dprintf on|off
4180 show disconnected-dprintf
4181 Control whether agent-style dynamic printfs continue to be in effect
4182 after GDB disconnects.
4184 * New configure options
4186 --with-auto-load-dir
4187 Configure default value for the 'set auto-load scripts-directory'
4188 setting above. It defaults to '$debugdir:$datadir/auto-load',
4189 $debugdir representing global debugging info directories (available
4190 via 'show debug-file-directory') and $datadir representing GDB's data
4191 directory (available via 'show data-directory').
4193 --with-auto-load-safe-path
4194 Configure default value for the 'set auto-load safe-path' setting
4195 above. It defaults to the --with-auto-load-dir setting.
4197 --without-auto-load-safe-path
4198 Set 'set auto-load safe-path' to '/', effectively disabling this
4201 * New remote packets
4203 z0/z1 conditional breakpoints extension
4205 The z0/z1 breakpoint insertion packets have been extended to carry
4206 a list of conditional expressions over to the remote stub depending on the
4207 condition evaluation mode. The use of this extension can be controlled
4208 via the "set remote conditional-breakpoints-packet" command.
4212 Specify the signals which the remote stub may pass to the debugged
4213 program without GDB involvement.
4215 * New command line options
4217 --init-command=FILE, -ix Like --command, -x but execute it
4218 before loading inferior.
4219 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4220 execute it before loading inferior.
4222 *** Changes in GDB 7.4
4224 * GDB now handles ambiguous linespecs more consistently; the existing
4225 FILE:LINE support has been expanded to other types of linespecs. A
4226 breakpoint will now be set on all matching locations in all
4227 inferiors, and locations will be added or removed according to
4230 * GDB now allows you to skip uninteresting functions and files when
4231 stepping with the "skip function" and "skip file" commands.
4233 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4234 and "show remote hardware-watchpoint-length-limit". These allows to
4235 set or show the maximum length limit (in bytes) of a remote
4236 target hardware watchpoint.
4238 This allows e.g. to use "unlimited" hardware watchpoints with the
4239 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
4240 watchpoints are slower than real hardware watchpoints but are
4241 significantly faster than gdb software watchpoints.
4245 ** The register_pretty_printer function in module gdb.printing now takes
4246 an optional `replace' argument. If True, the new printer replaces any
4249 ** The "maint set python print-stack on|off" command has been
4250 deprecated and will be deleted in GDB 7.5.
4251 A new command: "set python print-stack none|full|message" has
4252 replaced it. Additionally, the default for "print-stack" is
4253 now "message", which just prints the error message without
4256 ** A prompt substitution hook (prompt_hook) is now available to the
4259 ** A new Python module, gdb.prompt has been added to the GDB Python
4260 modules library. This module provides functionality for
4261 escape sequences in prompts (used by set/show
4262 extended-prompt). These escape sequences are replaced by their
4263 corresponding value.
4265 ** Python commands and convenience-functions located in
4266 'data-directory'/python/gdb/command and
4267 'data-directory'/python/gdb/function are now automatically loaded
4270 ** Blocks now provide four new attributes. global_block and
4271 static_block will return the global and static blocks
4272 respectively. is_static and is_global are boolean attributes
4273 that indicate if the block is one of those two types.
4275 ** Symbols now provide the "type" attribute, the type of the symbol.
4277 ** The "gdb.breakpoint" function has been deprecated in favor of
4280 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4281 of a function. This class is based on the "finish" command
4282 available in the CLI.
4284 ** Type objects for struct and union types now allow access to
4285 the fields using standard Python dictionary (mapping) methods.
4286 For example, "some_type['myfield']" now works, as does
4287 "some_type.items()".
4289 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4292 ** A new function, "deep_items" has been added to the gdb.types
4293 module in the GDB Python modules library. This function returns
4294 an iterator over the fields of a struct or union type. Unlike
4295 the standard Python "iteritems" method, it will recursively traverse
4296 any anonymous fields.
4300 ** "*stopped" events can report several new "reason"s, such as
4303 ** Breakpoint changes are now notified using new async records, like
4304 "=breakpoint-modified".
4306 ** New command -ada-task-info.
4308 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4309 $sdir specifies the default system locations of shared libraries.
4310 $pdir specifies the directory where the libpthread used by the application
4313 GDB no longer looks in $sdir and $pdir after it has searched the directories
4314 mentioned in libthread-db-search-path. If you want to search those
4315 directories, they must be specified in libthread-db-search-path.
4316 The default value of libthread-db-search-path on GNU/Linux and Solaris
4317 systems is now "$sdir:$pdir".
4319 $pdir is not supported by gdbserver, it is currently ignored.
4320 $sdir is supported by gdbserver.
4322 * New configure option --with-iconv-bin.
4323 When using the internationalization support like the one in the GNU C
4324 library, GDB will invoke the "iconv" program to get a list of supported
4325 character sets. If this program lives in a non-standard location, one can
4326 use this option to specify where to find it.
4328 * When natively debugging programs on PowerPC BookE processors running
4329 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4330 watchpoints, which specify a mask in addition to an address to watch.
4331 The mask specifies that some bits of an address (the bits which are
4332 reset in the mask) should be ignored when matching the address accessed
4333 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4334 section in the user manual for more details.
4336 * The new option --once causes GDBserver to stop listening for connections once
4337 the first connection is made. The listening port used by GDBserver will
4338 become available after that.
4340 * New commands "info macros" and "alias" have been added.
4342 * New function parameters suffix @entry specifies value of function parameter
4343 at the time the function got called. Entry values are available only since
4349 "!" is now an alias of the "shell" command.
4350 Note that no space is needed between "!" and SHELL COMMAND.
4354 watch EXPRESSION mask MASK_VALUE
4355 The watch command now supports the mask argument which allows creation
4356 of masked watchpoints, if the current architecture supports this feature.
4358 info auto-load-scripts [REGEXP]
4359 This command was formerly named "maintenance print section-scripts".
4360 It is now generally useful and is no longer a maintenance-only command.
4362 info macro [-all] [--] MACRO
4363 The info macro command has new options `-all' and `--'. The first for
4364 printing all definitions of a macro. The second for explicitly specifying
4365 the end of arguments and the beginning of the macro name in case the macro
4366 name starts with a hyphen.
4368 collect[/s] EXPRESSIONS
4369 The tracepoint collect command now takes an optional modifier "/s"
4370 that directs it to dereference pointer-to-character types and
4371 collect the bytes of memory up to a zero byte. The behavior is
4372 similar to what you see when you use the regular print command on a
4373 string. An optional integer following the "/s" sets a bound on the
4374 number of bytes that will be collected.
4377 The trace start command now interprets any supplied arguments as a
4378 note to be recorded with the trace run, with an effect similar to
4379 setting the variable trace-notes.
4382 The trace stop command now interprets any arguments as a note to be
4383 mentioned along with the tstatus report that the trace was stopped
4384 with a command. The effect is similar to setting the variable
4387 * Tracepoints can now be enabled and disabled at any time after a trace
4388 experiment has been started using the standard "enable" and "disable"
4389 commands. It is now possible to start a trace experiment with no enabled
4390 tracepoints; GDB will display a warning, but will allow the experiment to
4391 begin, assuming that tracepoints will be enabled as needed while the trace
4394 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4395 locations with 4-byte instructions, when they were previously
4396 limited to locations with instructions of 5 bytes or longer.
4400 set debug dwarf2-read
4401 show debug dwarf2-read
4402 Turns on or off display of debugging messages related to reading
4403 DWARF debug info. The default is off.
4405 set debug symtab-create
4406 show debug symtab-create
4407 Turns on or off display of debugging messages related to symbol table
4408 creation. The default is off.
4411 show extended-prompt
4412 Set the GDB prompt, and allow escape sequences to be inserted to
4413 display miscellaneous information (see 'help set extended-prompt'
4414 for the list of sequences). This prompt (and any information
4415 accessed through the escape sequences) is updated every time the
4416 prompt is displayed.
4418 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4419 show print entry-values
4420 Set printing of frame argument values at function entry. In some cases
4421 GDB can determine the value of function argument which was passed by the
4422 function caller, even if the value was modified inside the called function.
4424 set debug entry-values
4425 show debug entry-values
4426 Control display of debugging info for determining frame argument values at
4427 function entry and virtual tail call frames.
4429 set basenames-may-differ
4430 show basenames-may-differ
4431 Set whether a source file may have multiple base names.
4432 (A "base name" is the name of a file with the directory part removed.
4433 Example: The base name of "/home/user/hello.c" is "hello.c".)
4434 If set, GDB will canonicalize file names (e.g., expand symlinks)
4435 before comparing them. Canonicalization is an expensive operation,
4436 but it allows the same file be known by more than one base name.
4437 If not set (the default), all source files are assumed to have just
4438 one base name, and gdb will do file name comparisons more efficiently.
4444 Set a user name and notes for the current and any future trace runs.
4445 This is useful for long-running and/or disconnected traces, to
4446 inform others (or yourself) as to who is running the trace, supply
4447 contact information, or otherwise explain what is going on.
4449 set trace-stop-notes
4450 show trace-stop-notes
4451 Set a note attached to the trace run, that is displayed when the
4452 trace has been stopped by a tstop command. This is useful for
4453 instance as an explanation, if you are stopping a trace run that was
4454 started by someone else.
4456 * New remote packets
4460 Dynamically enable a tracepoint in a started trace experiment.
4464 Dynamically disable a tracepoint in a started trace experiment.
4468 Set the user and notes of the trace run.
4472 Query the current status of a tracepoint.
4476 Query the minimum length of instruction at which a fast tracepoint may
4479 * Dcache size (number of lines) and line-size are now runtime-configurable
4480 via "set dcache line" and "set dcache line-size" commands.
4484 Texas Instruments TMS320C6x tic6x-*-*
4488 Renesas RL78 rl78-*-elf
4490 *** Changes in GDB 7.3.1
4492 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4494 *** Changes in GDB 7.3
4496 * GDB has a new command: "thread find [REGEXP]".
4497 It finds the thread id whose name, target id, or thread extra info
4498 matches the given regular expression.
4500 * The "catch syscall" command now works on mips*-linux* targets.
4502 * The -data-disassemble MI command now supports modes 2 and 3 for
4503 dumping the instruction opcodes.
4505 * New command line options
4507 -data-directory DIR Specify DIR as the "data-directory".
4508 This is mostly for testing purposes.
4510 * The "maint set python auto-load on|off" command has been renamed to
4511 "set auto-load-scripts on|off".
4513 * GDB has a new command: "set directories".
4514 It is like the "dir" command except that it replaces the
4515 source path list instead of augmenting it.
4517 * GDB now understands thread names.
4519 On GNU/Linux, "info threads" will display the thread name as set by
4520 prctl or pthread_setname_np.
4522 There is also a new command, "thread name", which can be used to
4523 assign a name internally for GDB to display.
4526 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4527 has been integrated into GDB.
4531 ** The function gdb.Write now accepts an optional keyword 'stream'.
4532 This keyword, when provided, will direct the output to either
4533 stdout, stderr, or GDB's logging output.
4535 ** Parameters can now be be sub-classed in Python, and in particular
4536 you may implement the get_set_doc and get_show_doc functions.
4537 This improves how Parameter set/show documentation is processed
4538 and allows for more dynamic content.
4540 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4541 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4542 have an is_valid method.
4544 ** Breakpoints can now be sub-classed in Python, and in particular
4545 you may implement a 'stop' function that is executed each time
4546 the inferior reaches that breakpoint.
4548 ** New function gdb.lookup_global_symbol looks up a global symbol.
4550 ** GDB values in Python are now callable if the value represents a
4551 function. For example, if 'some_value' represents a function that
4552 takes two integer parameters and returns a value, you can call
4553 that function like so:
4555 result = some_value (10,20)
4557 ** Module gdb.types has been added.
4558 It contains a collection of utilities for working with gdb.Types objects:
4559 get_basic_type, has_field, make_enum_dict.
4561 ** Module gdb.printing has been added.
4562 It contains utilities for writing and registering pretty-printers.
4563 New classes: PrettyPrinter, SubPrettyPrinter,
4564 RegexpCollectionPrettyPrinter.
4565 New function: register_pretty_printer.
4567 ** New commands "info pretty-printers", "enable pretty-printer" and
4568 "disable pretty-printer" have been added.
4570 ** gdb.parameter("directories") is now available.
4572 ** New function gdb.newest_frame returns the newest frame in the
4575 ** The gdb.InferiorThread class has a new "name" attribute. This
4576 holds the thread's name.
4578 ** Python Support for Inferior events.
4579 Python scripts can add observers to be notified of events
4580 occurring in the process being debugged.
4581 The following events are currently supported:
4582 - gdb.events.cont Continue event.
4583 - gdb.events.exited Inferior exited event.
4584 - gdb.events.stop Signal received, and Breakpoint hit events.
4588 ** GDB now puts template parameters in scope when debugging in an
4589 instantiation. For example, if you have:
4591 template<int X> int func (void) { return X; }
4593 then if you step into func<5>, "print X" will show "5". This
4594 feature requires proper debuginfo support from the compiler; it
4595 was added to GCC 4.5.
4597 ** The motion commands "next", "finish", "until", and "advance" now
4598 work better when exceptions are thrown. In particular, GDB will
4599 no longer lose control of the inferior; instead, the GDB will
4600 stop the inferior at the point at which the exception is caught.
4601 This functionality requires a change in the exception handling
4602 code that was introduced in GCC 4.5.
4604 * GDB now follows GCC's rules on accessing volatile objects when
4605 reading or writing target state during expression evaluation.
4606 One notable difference to prior behavior is that "print x = 0"
4607 no longer generates a read of x; the value of the assignment is
4608 now always taken directly from the value being assigned.
4610 * GDB now has some support for using labels in the program's source in
4611 linespecs. For instance, you can use "advance label" to continue
4612 execution to a label.
4614 * GDB now has support for reading and writing a new .gdb_index
4615 section. This section holds a fast index of DWARF debugging
4616 information and can be used to greatly speed up GDB startup and
4617 operation. See the documentation for `save gdb-index' for details.
4619 * The "watch" command now accepts an optional "-location" argument.
4620 When used, this causes GDB to watch the memory referred to by the
4621 expression. Such a watchpoint is never deleted due to it going out
4624 * GDB now supports thread debugging of core dumps on GNU/Linux.
4626 GDB now activates thread debugging using the libthread_db library
4627 when debugging GNU/Linux core dumps, similarly to when debugging
4628 live processes. As a result, when debugging a core dump file, GDB
4629 is now able to display pthread_t ids of threads. For example, "info
4630 threads" shows the same output as when debugging the process when it
4631 was live. In earlier releases, you'd see something like this:
4634 * 1 LWP 6780 main () at main.c:10
4636 While now you see this:
4639 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4641 It is also now possible to inspect TLS variables when debugging core
4644 When debugging a core dump generated on a machine other than the one
4645 used to run GDB, you may need to point GDB at the correct
4646 libthread_db library with the "set libthread-db-search-path"
4647 command. See the user manual for more details on this command.
4649 * When natively debugging programs on PowerPC BookE processors running
4650 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4651 which stop execution of the inferior whenever it executes an instruction
4652 at any address within the specified range. See the "PowerPC Embedded"
4653 section in the user manual for more details.
4655 * New features in the GDB remote stub, GDBserver
4657 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4658 and i686 LynxOS (version 5.x).
4660 ** GDBserver is now supported on Blackfin Linux.
4662 * New native configurations
4664 ia64 HP-UX ia64-*-hpux*
4668 Analog Devices, Inc. Blackfin Processor bfin-*
4670 * Ada task switching is now supported on sparc-elf targets when
4671 debugging a program using the Ravenscar Profile. For more information,
4672 see the "Tasking Support when using the Ravenscar Profile" section
4673 in the GDB user manual.
4675 * Guile support was removed.
4677 * New features in the GNU simulator
4679 ** The --map-info flag lists all known core mappings.
4681 ** CFI flashes may be simulated via the "cfi" device.
4683 *** Changes in GDB 7.2
4685 * Shared library support for remote targets by default
4687 When GDB is configured for a generic, non-OS specific target, like
4688 for example, --target=arm-eabi or one of the many *-*-elf targets,
4689 GDB now queries remote stubs for loaded shared libraries using the
4690 `qXfer:libraries:read' packet. Previously, shared library support
4691 was always disabled for such configurations.
4695 ** Argument Dependent Lookup (ADL)
4697 In C++ ADL lookup directs function search to the namespaces of its
4698 arguments even if the namespace has not been imported.
4708 Here the compiler will search for `foo' in the namespace of 'b'
4709 and find A::foo. GDB now supports this. This construct is commonly
4710 used in the Standard Template Library for operators.
4712 ** Improved User Defined Operator Support
4714 In addition to member operators, GDB now supports lookup of operators
4715 defined in a namespace and imported with a `using' directive, operators
4716 defined in the global scope, operators imported implicitly from an
4717 anonymous namespace, and the ADL operators mentioned in the previous
4719 GDB now also supports proper overload resolution for all the previously
4720 mentioned flavors of operators.
4722 ** static const class members
4724 Printing of static const class members that are initialized in the
4725 class definition has been fixed.
4727 * Windows Thread Information Block access.
4729 On Windows targets, GDB now supports displaying the Windows Thread
4730 Information Block (TIB) structure. This structure is visible either
4731 by using the new command `info w32 thread-information-block' or, by
4732 dereferencing the new convenience variable named `$_tlb', a
4733 thread-specific pointer to the TIB. This feature is also supported
4734 when remote debugging using GDBserver.
4736 * Static tracepoints
4738 Static tracepoints are calls in the user program into a tracing
4739 library. One such library is a port of the LTTng kernel tracer to
4740 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4741 When debugging with GDBserver, GDB now supports combining the GDB
4742 tracepoint machinery with such libraries. For example: the user can
4743 use GDB to probe a static tracepoint marker (a call from the user
4744 program into the tracing library) with the new "strace" command (see
4745 "New commands" below). This creates a "static tracepoint" in the
4746 breakpoint list, that can be manipulated with the same feature set
4747 as fast and regular tracepoints. E.g., collect registers, local and
4748 global variables, collect trace state variables, and define
4749 tracepoint conditions. In addition, the user can collect extra
4750 static tracepoint marker specific data, by collecting the new
4751 $_sdata internal variable. When analyzing the trace buffer, you can
4752 inspect $_sdata like any other variable available to GDB. For more
4753 information, see the "Tracepoints" chapter in GDB user manual. New
4754 remote packets have been defined to support static tracepoints, see
4755 the "New remote packets" section below.
4757 * Better reconstruction of tracepoints after disconnected tracing
4759 GDB will attempt to download the original source form of tracepoint
4760 definitions when starting a trace run, and then will upload these
4761 upon reconnection to the target, resulting in a more accurate
4762 reconstruction of the tracepoints that are in use on the target.
4766 You can now exercise direct control over the ways that GDB can
4767 affect your program. For instance, you can disallow the setting of
4768 breakpoints, so that the program can run continuously (assuming
4769 non-stop mode). In addition, the "observer" variable is available
4770 to switch all of the different controls; in observer mode, GDB
4771 cannot affect the target's behavior at all, which is useful for
4772 tasks like diagnosing live systems in the field.
4774 * The new convenience variable $_thread holds the number of the
4777 * New remote packets
4781 Return the address of the Windows Thread Information Block of a given thread.
4785 In response to several of the tracepoint packets, the target may now
4786 also respond with a number of intermediate `qRelocInsn' request
4787 packets before the final result packet, to have GDB handle
4788 relocating an instruction to execute at a different address. This
4789 is particularly useful for stubs that support fast tracepoints. GDB
4790 reports support for this feature in the qSupported packet.
4794 List static tracepoint markers in the target program.
4798 List static tracepoint markers at a given address in the target
4801 qXfer:statictrace:read
4803 Read the static trace data collected (by a `collect $_sdata'
4804 tracepoint action). The remote stub reports support for this packet
4805 to gdb's qSupported query.
4809 Send the current settings of GDB's permission flags.
4813 Send part of the source (textual) form of a tracepoint definition,
4814 which includes location, conditional, and action list.
4816 * The source command now accepts a -s option to force searching for the
4817 script in the source search path even if the script name specifies
4820 * New features in the GDB remote stub, GDBserver
4822 - GDBserver now support tracepoints (including fast tracepoints, and
4823 static tracepoints). The feature is currently supported by the
4824 i386-linux and amd64-linux builds. See the "Tracepoints support
4825 in gdbserver" section in the manual for more information.
4827 GDBserver JIT compiles the tracepoint's conditional agent
4828 expression bytecode into native code whenever possible for low
4829 overhead dynamic tracepoints conditionals. For such tracepoints,
4830 an expression that examines program state is evaluated when the
4831 tracepoint is reached, in order to determine whether to capture
4832 trace data. If the condition is simple and false, processing the
4833 tracepoint finishes very quickly and no data is gathered.
4835 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4836 for static tracepoints support.
4838 - GDBserver now supports x86_64 Windows 64-bit debugging.
4840 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4841 it understands register description.
4843 * The --batch flag now disables pagination and queries.
4845 * X86 general purpose registers
4847 GDB now supports reading/writing byte, word and double-word x86
4848 general purpose registers directly. This means you can use, say,
4849 $ah or $ax to refer, respectively, to the byte register AH and
4850 16-bit word register AX that are actually portions of the 32-bit
4851 register EAX or 64-bit register RAX.
4853 * The `commands' command now accepts a range of breakpoints to modify.
4854 A plain `commands' following a command that creates multiple
4855 breakpoints affects all the breakpoints set by that command. This
4856 applies to breakpoints set by `rbreak', and also applies when a
4857 single `break' command creates multiple breakpoints (e.g.,
4858 breakpoints on overloaded c++ functions).
4860 * The `rbreak' command now accepts a filename specification as part of
4861 its argument, limiting the functions selected by the regex to those
4862 in the specified file.
4864 * Support for remote debugging Windows and SymbianOS shared libraries
4865 from Unix hosts has been improved. Non Windows GDB builds now can
4866 understand target reported file names that follow MS-DOS based file
4867 system semantics, such as file names that include drive letters and
4868 use the backslash character as directory separator. This makes it
4869 possible to transparently use the "set sysroot" and "set
4870 solib-search-path" on Unix hosts to point as host copies of the
4871 target's shared libraries. See the new command "set
4872 target-file-system-kind" described below, and the "Commands to
4873 specify files" section in the user manual for more information.
4877 eval template, expressions...
4878 Convert the values of one or more expressions under the control
4879 of the string template to a command line, and call it.
4881 set target-file-system-kind unix|dos-based|auto
4882 show target-file-system-kind
4883 Set or show the assumed file system kind for target reported file
4886 save breakpoints <filename>
4887 Save all current breakpoint definitions to a file suitable for use
4888 in a later debugging session. To read the saved breakpoint
4889 definitions, use the `source' command.
4891 `save tracepoints' is a new alias for `save-tracepoints'. The latter
4894 info static-tracepoint-markers
4895 Display information about static tracepoint markers in the target.
4897 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
4898 Define a static tracepoint by probing a marker at the given
4899 function, line, address, or marker ID.
4903 Enable and disable observer mode.
4905 set may-write-registers on|off
4906 set may-write-memory on|off
4907 set may-insert-breakpoints on|off
4908 set may-insert-tracepoints on|off
4909 set may-insert-fast-tracepoints on|off
4910 set may-interrupt on|off
4911 Set individual permissions for GDB effects on the target. Note that
4912 some of these settings can have undesirable or surprising
4913 consequences, particularly when changed in the middle of a session.
4914 For instance, disabling the writing of memory can prevent
4915 breakpoints from being inserted, cause single-stepping to fail, or
4916 even crash your program, if you disable after breakpoints have been
4917 inserted. However, GDB should not crash.
4919 set record memory-query on|off
4920 show record memory-query
4921 Control whether to stop the inferior if memory changes caused
4922 by an instruction cannot be recorded.
4927 The disassemble command now supports "start,+length" form of two arguments.
4931 ** GDB now provides a new directory location, called the python directory,
4932 where Python scripts written for GDB can be installed. The location
4933 of that directory is <data-directory>/python, where <data-directory>
4934 is the GDB data directory. For more details, see section `Scripting
4935 GDB using Python' in the manual.
4937 ** The GDB Python API now has access to breakpoints, symbols, symbol
4938 tables, program spaces, inferiors, threads and frame's code blocks.
4939 Additionally, GDB Parameters can now be created from the API, and
4940 manipulated via set/show in the CLI.
4942 ** New functions gdb.target_charset, gdb.target_wide_charset,
4943 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
4945 ** New exception gdb.GdbError.
4947 ** Pretty-printers are now also looked up in the current program space.
4949 ** Pretty-printers can now be individually enabled and disabled.
4951 ** GDB now looks for names of Python scripts to auto-load in a
4952 special section named `.debug_gdb_scripts', in addition to looking
4953 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
4955 * Tracepoint actions were unified with breakpoint commands. In particular,
4956 there are no longer differences in "info break" output for breakpoints and
4957 tracepoints and the "commands" command can be used for both tracepoints and
4958 regular breakpoints.
4962 ARM Symbian arm*-*-symbianelf*
4964 * D language support.
4965 GDB now supports debugging programs written in the D programming
4968 * GDB now supports the extended ptrace interface for PowerPC which is
4969 available since Linux kernel version 2.6.34. This automatically enables
4970 any hardware breakpoints and additional hardware watchpoints available in
4971 the processor. The old ptrace interface exposes just one hardware
4972 watchpoint and no hardware breakpoints.
4974 * GDB is now able to use the Data Value Compare (DVC) register available on
4975 embedded PowerPC processors to implement in hardware simple watchpoint
4976 conditions of the form:
4978 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
4980 This works in native GDB running on Linux kernels with the extended ptrace
4981 interface mentioned above.
4983 *** Changes in GDB 7.1
4987 ** Namespace Support
4989 GDB now supports importing of namespaces in C++. This enables the
4990 user to inspect variables from imported namespaces. Support for
4991 namepace aliasing has also been added. So, if a namespace is
4992 aliased in the current scope (e.g. namepace C=A; ) the user can
4993 print variables using the alias (e.g. (gdb) print C::x).
4997 All known bugs relating to the printing of virtual base class were
4998 fixed. It is now possible to call overloaded static methods using a
5003 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5004 and reinterpret_cast<> are now handled by the C++ expression parser.
5008 Xilinx MicroBlaze microblaze-*-*
5013 Xilinx MicroBlaze microblaze
5016 * Multi-program debugging.
5018 GDB now has support for multi-program (a.k.a. multi-executable or
5019 multi-exec) debugging. This allows for debugging multiple inferiors
5020 simultaneously each running a different program under the same GDB
5021 session. See "Debugging Multiple Inferiors and Programs" in the
5022 manual for more information. This implied some user visible changes
5023 in the multi-inferior support. For example, "info inferiors" now
5024 lists inferiors that are not running yet or that have exited
5025 already. See also "New commands" and "New options" below.
5027 * New tracing features
5029 GDB's tracepoint facility now includes several new features:
5031 ** Trace state variables
5033 GDB tracepoints now include support for trace state variables, which
5034 are variables managed by the target agent during a tracing
5035 experiment. They are useful for tracepoints that trigger each
5036 other, so for instance one tracepoint can count hits in a variable,
5037 and then a second tracepoint has a condition that is true when the
5038 count reaches a particular value. Trace state variables share the
5039 $-syntax of GDB convenience variables, and can appear in both
5040 tracepoint actions and condition expressions. Use the "tvariable"
5041 command to create, and "info tvariables" to view; see "Trace State
5042 Variables" in the manual for more detail.
5046 GDB now includes an option for defining fast tracepoints, which
5047 targets may implement more efficiently, such as by installing a jump
5048 into the target agent rather than a trap instruction. The resulting
5049 speedup can be by two orders of magnitude or more, although the
5050 tradeoff is that some program locations on some target architectures
5051 might not allow fast tracepoint installation, for instance if the
5052 instruction to be replaced is shorter than the jump. To request a
5053 fast tracepoint, use the "ftrace" command, with syntax identical to
5054 the regular trace command.
5056 ** Disconnected tracing
5058 It is now possible to detach GDB from the target while it is running
5059 a trace experiment, then reconnect later to see how the experiment
5060 is going. In addition, a new variable disconnected-tracing lets you
5061 tell the target agent whether to continue running a trace if the
5062 connection is lost unexpectedly.
5066 GDB now has the ability to save the trace buffer into a file, and
5067 then use that file as a target, similarly to you can do with
5068 corefiles. You can select trace frames, print data that was
5069 collected in them, and use tstatus to display the state of the
5070 tracing run at the moment that it was saved. To create a trace
5071 file, use "tsave <filename>", and to use it, do "target tfile
5074 ** Circular trace buffer
5076 You can ask the target agent to handle the trace buffer as a
5077 circular buffer, discarding the oldest trace frames to make room for
5078 newer ones, by setting circular-trace-buffer to on. This feature may
5079 not be available for all target agents.
5084 The disassemble command, when invoked with two arguments, now requires
5085 the arguments to be comma-separated.
5088 The info variables command now displays variable definitions. Files
5089 which only declare a variable are not shown.
5092 The source command is now capable of sourcing Python scripts.
5093 This feature is dependent on the debugger being build with Python
5096 Related to this enhancement is also the introduction of a new command
5097 "set script-extension" (see below).
5099 * New commands (for set/show, see "New options" below)
5101 record save [<FILENAME>]
5102 Save a file (in core file format) containing the process record
5103 execution log for replay debugging at a later time.
5105 record restore <FILENAME>
5106 Restore the process record execution log that was saved at an
5107 earlier time, for replay debugging.
5109 add-inferior [-copies <N>] [-exec <FILENAME>]
5112 clone-inferior [-copies <N>] [ID]
5113 Make a new inferior ready to execute the same program another
5114 inferior has loaded.
5119 maint info program-spaces
5120 List the program spaces loaded into GDB.
5122 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5123 show remote interrupt-sequence
5124 Allow the user to select one of ^C, a BREAK signal or BREAK-g
5125 as the sequence to the remote target in order to interrupt the execution.
5126 Ctrl-C is a default. Some system prefers BREAK which is high level of
5127 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
5128 Magic SysRq g. It is BREAK signal and character 'g'.
5130 set remote interrupt-on-connect [on | off]
5131 show remote interrupt-on-connect
5132 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5133 remote target when gdb connects to it. This is needed when you debug
5136 set remotebreak [on | off]
5138 Deprecated. Use "set/show remote interrupt-sequence" instead.
5140 tvariable $NAME [ = EXP ]
5141 Create or modify a trace state variable.
5144 List trace state variables and their values.
5146 delete tvariable $NAME ...
5147 Delete one or more trace state variables.
5150 Evaluate the given expressions without collecting anything into the
5151 trace buffer. (Valid in tracepoint actions only.)
5153 ftrace FN / FILE:LINE / *ADDR
5154 Define a fast tracepoint at the given function, line, or address.
5156 * New expression syntax
5158 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5159 GDB now parses 0b101010 identically with 42.
5163 set follow-exec-mode new|same
5164 show follow-exec-mode
5165 Control whether GDB reuses the same inferior across an exec call or
5166 creates a new one. This is useful to be able to restart the old
5167 executable after the inferior having done an exec call.
5169 set default-collect EXPR, ...
5170 show default-collect
5171 Define a list of expressions to be collected at each tracepoint.
5172 This is a useful way to ensure essential items are not overlooked,
5173 such as registers or a critical global variable.
5175 set disconnected-tracing
5176 show disconnected-tracing
5177 If set to 1, the target is instructed to continue tracing if it
5178 loses its connection to GDB. If 0, the target is to stop tracing
5181 set circular-trace-buffer
5182 show circular-trace-buffer
5183 If set to on, the target is instructed to use a circular trace buffer
5184 and discard the oldest trace frames instead of stopping the trace due
5185 to a full trace buffer. If set to off, the trace stops when the buffer
5186 fills up. Some targets may not support this.
5188 set script-extension off|soft|strict
5189 show script-extension
5190 If set to "off", the debugger does not perform any script language
5191 recognition, and all sourced files are assumed to be GDB scripts.
5192 If set to "soft" (the default), files are sourced according to
5193 filename extension, falling back to GDB scripts if the first
5195 If set to "strict", files are sourced according to filename extension.
5197 set ada trust-PAD-over-XVS on|off
5198 show ada trust-PAD-over-XVS
5199 If off, activate a workaround against a bug in the debugging information
5200 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5201 the GCC sources for more information about the GNAT encoding and
5202 PAD types in particular). It is always safe to set this option to
5203 off, but this introduces a slight performance penalty. The default
5206 * Python API Improvements
5208 ** GDB provides the new class gdb.LazyString. This is useful in
5209 some pretty-printing cases. The new method gdb.Value.lazy_string
5210 provides a simple way to create objects of this type.
5212 ** The fields returned by gdb.Type.fields now have an
5213 `is_base_class' attribute.
5215 ** The new method gdb.Type.range returns the range of an array type.
5217 ** The new method gdb.parse_and_eval can be used to parse and
5218 evaluate an expression.
5220 * New remote packets
5223 Define a trace state variable.
5226 Get the current value of a trace state variable.
5229 Set desired tracing behavior upon disconnection.
5232 Set the trace buffer to be linear or circular.
5235 Get data about the tracepoints currently in use.
5239 Process record now works correctly with hardware watchpoints.
5241 Multiple bug fixes have been made to the mips-irix port, making it
5242 much more reliable. In particular:
5243 - Debugging threaded applications is now possible again. Previously,
5244 GDB would hang while starting the program, or while waiting for
5245 the program to stop at a breakpoint.
5246 - Attaching to a running process no longer hangs.
5247 - An error occurring while loading a core file has been fixed.
5248 - Changing the value of the PC register now works again. This fixes
5249 problems observed when using the "jump" command, or when calling
5250 a function from GDB, or even when assigning a new value to $pc.
5251 - With the "finish" and "return" commands, the return value for functions
5252 returning a small array is now correctly printed.
5253 - It is now possible to break on shared library code which gets executed
5254 during a shared library init phase (code executed while executing
5255 their .init section). Previously, the breakpoint would have no effect.
5256 - GDB is now able to backtrace through the signal handler for
5257 non-threaded programs.
5259 PIE (Position Independent Executable) programs debugging is now supported.
5260 This includes debugging execution of PIC (Position Independent Code) shared
5261 libraries although for that, it should be possible to run such libraries as an
5264 *** Changes in GDB 7.0
5266 * GDB now has an interface for JIT compilation. Applications that
5267 dynamically generate code can create symbol files in memory and register
5268 them with GDB. For users, the feature should work transparently, and
5269 for JIT developers, the interface is documented in the GDB manual in the
5270 "JIT Compilation Interface" chapter.
5272 * Tracepoints may now be conditional. The syntax is as for
5273 breakpoints; either an "if" clause appended to the "trace" command,
5274 or the "condition" command is available. GDB sends the condition to
5275 the target for evaluation using the same bytecode format as is used
5276 for tracepoint actions.
5278 * The disassemble command now supports: an optional /r modifier, print the
5279 raw instructions in hex as well as in symbolic form, and an optional /m
5280 modifier to print mixed source+assembly.
5282 * Process record and replay
5284 In a architecture environment that supports ``process record and
5285 replay'', ``process record and replay'' target can record a log of
5286 the process execution, and replay it with both forward and reverse
5289 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5290 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5291 set execution-direction {forward|reverse}, for targets that support
5294 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5295 feature is available with a native GDB running on kernel version
5298 * GDB now has support for multi-byte and wide character sets on the
5299 target. Strings whose character type is wchar_t, char16_t, or
5300 char32_t are now correctly printed. GDB supports wide- and unicode-
5301 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5302 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5303 `printf'. This feature requires iconv to work properly; if your
5304 system does not have a working iconv, GDB can use GNU libiconv. See
5305 the installation instructions for more information.
5307 * GDB now supports automatic retrieval of shared library files from
5308 remote targets. To use this feature, specify a system root that begins
5309 with the `remote:' prefix, either via the `set sysroot' command or via
5310 the `--with-sysroot' configure-time option.
5312 * "info sharedlibrary" now takes an optional regex of libraries to show,
5313 and it now reports if a shared library has no debugging information.
5315 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5316 now complete on file names.
5318 * When completing in expressions, gdb will attempt to limit
5319 completions to allowable structure or union fields, where appropriate.
5320 For instance, consider:
5322 # struct example { int f1; double f2; };
5323 # struct example variable;
5326 If the user types TAB at the end of this command line, the available
5327 completions will be "f1" and "f2".
5329 * Inlined functions are now supported. They show up in backtraces, and
5330 the "step", "next", and "finish" commands handle them automatically.
5332 * GDB now supports the token-splicing (##) and stringification (#)
5333 operators when expanding macros. It also supports variable-arity
5336 * GDB now supports inspecting extra signal information, exported by
5337 the new $_siginfo convenience variable. The feature is currently
5338 implemented on linux ARM, i386 and amd64.
5340 * GDB can now display the VFP floating point registers and NEON vector
5341 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5342 can provide these registers (requires Linux 2.6.30 or later). Remote
5343 and simulator targets may also provide them.
5345 * New remote packets
5348 Search memory for a sequence of bytes.
5351 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5352 operation over reliable transport links. Use of this packet is
5353 controlled by the `set remote noack-packet' command.
5356 Kill the process with the specified process ID. Use this in preference
5357 to `k' when multiprocess protocol extensions are supported.
5360 Obtains additional operating system information
5364 Read or write additional signal information.
5366 * Removed remote protocol undocumented extension
5368 An undocumented extension to the remote protocol's `S' stop reply
5369 packet that permitted the stub to pass a process id was removed.
5370 Remote servers should use the `T' stop reply packet instead.
5372 * GDB now supports multiple function calling conventions according to the
5373 DWARF-2 DW_AT_calling_convention function attribute.
5375 * The SH target utilizes the aforementioned change to distinguish between gcc
5376 and Renesas calling convention. It also adds the new CLI commands
5377 `set/show sh calling-convention'.
5379 * GDB can now read compressed debug sections, as produced by GNU gold
5380 with the --compress-debug-sections=zlib flag.
5382 * 64-bit core files are now supported on AIX.
5384 * Thread switching is now supported on Tru64.
5386 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5387 which will be allocated using malloc later in program execution.
5389 * The qXfer:libraries:read remote protocol packet now allows passing a
5390 list of section offsets.
5392 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5393 conditions handling signals delivered during attach or thread creation
5394 have also been fixed.
5396 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5397 From the user's standpoint, all unqualified instances of True and False
5398 are treated as the standard definitions, regardless of context.
5400 * GDB now parses C++ symbol and type names more flexibly. For
5403 template<typename T> class C { };
5406 GDB will now correctly handle all of:
5408 ptype C<char const *>
5409 ptype C<char const*>
5410 ptype C<const char *>
5411 ptype C<const char*>
5413 * New features in the GDB remote stub, gdbserver
5415 - The "--wrapper" command-line argument tells gdbserver to use a
5416 wrapper program to launch programs for debugging.
5418 - On PowerPC and S/390 targets, it is now possible to use a single
5419 gdbserver executable to debug both 32-bit and 64-bit programs.
5420 (This requires gdbserver itself to be built as a 64-bit executable.)
5422 - gdbserver uses the new noack protocol mode for TCP connections to
5423 reduce communications latency, if also supported and enabled in GDB.
5425 - Support for the sparc64-linux-gnu target is now included in
5428 - The amd64-linux build of gdbserver now supports debugging both
5429 32-bit and 64-bit programs.
5431 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5432 now support hardware watchpoints, and will use them automatically
5437 GDB now has support for scripting using Python. Whether this is
5438 available is determined at configure time.
5440 New GDB commands can now be written in Python.
5442 * Ada tasking support
5444 Ada tasks can now be inspected in GDB. The following commands have
5448 Print the list of Ada tasks.
5450 Print detailed information about task number N.
5452 Print the task number of the current task.
5454 Switch the context of debugging to task number N.
5456 * Support for user-defined prefixed commands. The "define" command can
5457 add new commands to existing prefixes, e.g. "target".
5459 * Multi-inferior, multi-process debugging.
5461 GDB now has generalized support for multi-inferior debugging. See
5462 "Debugging Multiple Inferiors" in the manual for more information.
5463 Although availability still depends on target support, the command
5464 set is more uniform now. The GNU/Linux specific multi-forks support
5465 has been migrated to this new framework. This implied some user
5466 visible changes; see "New commands" and also "Removed commands"
5469 * Target descriptions can now describe the target OS ABI. See the
5470 "Target Description Format" section in the user manual for more
5473 * Target descriptions can now describe "compatible" architectures
5474 to indicate that the target can execute applications for a different
5475 architecture in addition to those for the main target architecture.
5476 See the "Target Description Format" section in the user manual for
5479 * Multi-architecture debugging.
5481 GDB now includes general supports for debugging applications on
5482 hybrid systems that use more than one single processor architecture
5483 at the same time. Each such hybrid architecture still requires
5484 specific support to be added. The only hybrid architecture supported
5485 in this version of GDB is the Cell Broadband Engine.
5487 * GDB now supports integrated debugging of Cell/B.E. applications that
5488 use both the PPU and SPU architectures. To enable support for hybrid
5489 Cell/B.E. debugging, you need to configure GDB to support both the
5490 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5491 --enable-targets configure option.
5493 * Non-stop mode debugging.
5495 For some targets, GDB now supports an optional mode of operation in
5496 which you can examine stopped threads while other threads continue
5497 to execute freely. This is referred to as non-stop mode, with the
5498 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5499 section in the user manual for more information.
5501 To be able to support remote non-stop debugging, a remote stub needs
5502 to implement the non-stop mode remote protocol extensions, as
5503 described in the "Remote Non-Stop" section of the user manual. The
5504 GDB remote stub, gdbserver, has been adjusted to support these
5505 extensions on linux targets.
5507 * New commands (for set/show, see "New options" below)
5509 catch syscall [NAME(S) | NUMBER(S)]
5510 Catch system calls. Arguments, which should be names of system
5511 calls or their numbers, mean catch only those syscalls. Without
5512 arguments, every syscall will be caught. When the inferior issues
5513 any of the specified syscalls, GDB will stop and announce the system
5514 call, both when it is called and when its call returns. This
5515 feature is currently available with a native GDB running on the
5516 Linux Kernel, under the following architectures: x86, x86_64,
5517 PowerPC and PowerPC64.
5519 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5521 Search memory for a sequence of bytes.
5523 maint set python print-stack
5524 maint show python print-stack
5525 Show a stack trace when an error is encountered in a Python script.
5528 Invoke CODE by passing it to the Python interpreter.
5533 These allow macros to be defined, undefined, and listed
5537 Show operating system information about processes.
5540 List the inferiors currently under GDB's control.
5543 Switch focus to inferior number NUM.
5546 Detach from inferior number NUM.
5549 Kill inferior number NUM.
5553 set spu stop-on-load
5554 show spu stop-on-load
5555 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5557 set spu auto-flush-cache
5558 show spu auto-flush-cache
5559 Control whether to automatically flush the software-managed cache
5560 during Cell/B.E. debugging.
5562 set sh calling-convention
5563 show sh calling-convention
5564 Control the calling convention used when calling SH target functions.
5567 show debug timestamp
5568 Control display of timestamps with GDB debugging output.
5570 set disassemble-next-line
5571 show disassemble-next-line
5572 Control display of disassembled source lines or instructions when
5575 set remote noack-packet
5576 show remote noack-packet
5577 Set/show the use of remote protocol QStartNoAckMode packet. See above
5578 under "New remote packets."
5580 set remote query-attached-packet
5581 show remote query-attached-packet
5582 Control use of remote protocol `qAttached' (query-attached) packet.
5584 set remote read-siginfo-object
5585 show remote read-siginfo-object
5586 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5589 set remote write-siginfo-object
5590 show remote write-siginfo-object
5591 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5594 set remote reverse-continue
5595 show remote reverse-continue
5596 Control use of remote protocol 'bc' (reverse-continue) packet.
5598 set remote reverse-step
5599 show remote reverse-step
5600 Control use of remote protocol 'bs' (reverse-step) packet.
5602 set displaced-stepping
5603 show displaced-stepping
5604 Control displaced stepping mode. Displaced stepping is a way to
5605 single-step over breakpoints without removing them from the debuggee.
5606 Also known as "out-of-line single-stepping".
5609 show debug displaced
5610 Control display of debugging info for displaced stepping.
5612 maint set internal-error
5613 maint show internal-error
5614 Control what GDB does when an internal error is detected.
5616 maint set internal-warning
5617 maint show internal-warning
5618 Control what GDB does when an internal warning is detected.
5623 Use a wrapper program to launch programs for debugging.
5625 set multiple-symbols (all|ask|cancel)
5626 show multiple-symbols
5627 The value of this variable can be changed to adjust the debugger behavior
5628 when an expression or a breakpoint location contains an ambiguous symbol
5629 name (an overloaded function name, for instance).
5631 set breakpoint always-inserted
5632 show breakpoint always-inserted
5633 Keep breakpoints always inserted in the target, as opposed to inserting
5634 them when resuming the target, and removing them when the target stops.
5635 This option can improve debugger performance on slow remote targets.
5637 set arm fallback-mode (arm|thumb|auto)
5638 show arm fallback-mode
5639 set arm force-mode (arm|thumb|auto)
5641 These commands control how ARM GDB determines whether instructions
5642 are ARM or Thumb. The default for both settings is auto, which uses
5643 the current CPSR value for instructions without symbols; previous
5644 versions of GDB behaved as if "set arm fallback-mode arm".
5646 set arm unwind-secure-frames
5647 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5649 This can trigger security exceptions when unwinding exception stacks.
5651 set disable-randomization
5652 show disable-randomization
5653 Standalone programs run with the virtual address space randomization enabled
5654 by default on some platforms. This option keeps the addresses stable across
5655 multiple debugging sessions.
5659 Control whether other threads are stopped or not when some thread hits
5664 Requests that asynchronous execution is enabled in the target, if available.
5665 In this case, it's possible to resume target in the background, and interact
5666 with GDB while the target is running. "show target-async" displays the
5667 current state of asynchronous execution of the target.
5669 set target-wide-charset
5670 show target-wide-charset
5671 The target-wide-charset is the name of the character set that GDB
5672 uses when printing characters whose type is wchar_t.
5674 set tcp auto-retry (on|off)
5676 set tcp connect-timeout
5677 show tcp connect-timeout
5678 These commands allow GDB to retry failed TCP connections to a remote stub
5679 with a specified timeout period; this is useful if the stub is launched
5680 in parallel with GDB but may not be ready to accept connections immediately.
5682 set libthread-db-search-path
5683 show libthread-db-search-path
5684 Control list of directories which GDB will search for appropriate
5687 set schedule-multiple (on|off)
5688 show schedule-multiple
5689 Allow GDB to resume all threads of all processes or only threads of
5690 the current process.
5694 Use more aggressive caching for accesses to the stack. This improves
5695 performance of remote debugging (particularly backtraces) without
5696 affecting correctness.
5698 set interactive-mode (on|off|auto)
5699 show interactive-mode
5700 Control whether GDB runs in interactive mode (on) or not (off).
5701 When in interactive mode, GDB waits for the user to answer all
5702 queries. Otherwise, GDB does not wait and assumes the default
5703 answer. When set to auto (the default), GDB determines which
5704 mode to use based on the stdin settings.
5709 For program forks, this is replaced by the new more generic `info
5710 inferiors' command. To list checkpoints, you can still use the
5711 `info checkpoints' command, which was an alias for the `info forks'
5715 Replaced by the new `inferior' command. To switch between
5716 checkpoints, you can still use the `restart' command, which was an
5717 alias for the `fork' command.
5720 This is removed, since some targets don't have a notion of
5721 processes. To switch between processes, you can still use the
5722 `inferior' command using GDB's own inferior number.
5725 For program forks, this is replaced by the new more generic `kill
5726 inferior' command. To delete a checkpoint, you can still use the
5727 `delete checkpoint' command, which was an alias for the `delete
5731 For program forks, this is replaced by the new more generic `detach
5732 inferior' command. To detach a checkpoint, you can still use the
5733 `detach checkpoint' command, which was an alias for the `detach
5736 * New native configurations
5738 x86/x86_64 Darwin i[34567]86-*-darwin*
5740 x86_64 MinGW x86_64-*-mingw*
5744 Lattice Mico32 lm32-*
5745 x86 DICOS i[34567]86-*-dicos*
5746 x86_64 DICOS x86_64-*-dicos*
5749 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5750 (mingw32ce) debugging.
5756 These commands were actually not implemented on any target.
5758 *** Changes in GDB 6.8
5760 * New native configurations
5762 NetBSD/hppa hppa*-*netbsd*
5763 Xtensa GNU/Linux xtensa*-*-linux*
5767 NetBSD/hppa hppa*-*-netbsd*
5768 Xtensa GNU/Linux xtensa*-*-linux*
5770 * Change in command line behavior -- corefiles vs. process ids.
5772 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5773 attaching to process NUMBER fails, GDB no longer attempts to open a
5774 core file named NUMBER. Attaching to a program using the -c option
5775 is no longer supported. Instead, use the '-p' or '--pid' options.
5777 * GDB can now be built as a native debugger for debugging Windows x86
5778 (mingw32) Portable Executable (PE) programs.
5780 * Pending breakpoints no longer change their number when their address
5783 * GDB now supports breakpoints with multiple locations,
5784 including breakpoints on C++ constructors, inside C++ templates,
5785 and in inlined functions.
5787 * GDB's ability to debug optimized code has been improved. GDB more
5788 accurately identifies function bodies and lexical blocks that occupy
5789 more than one contiguous range of addresses.
5791 * Target descriptions can now describe registers for PowerPC.
5793 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5794 registers on PowerPC targets.
5796 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5797 targets even when the libthread_db library is not available.
5799 * The GDB remote stub, gdbserver, now supports the new file transfer
5800 commands (remote put, remote get, and remote delete).
5802 * The GDB remote stub, gdbserver, now supports run and attach in
5803 extended-remote mode.
5805 * hppa*64*-*-hpux11* target broken
5806 The debugger is unable to start a program and fails with the following
5807 error: "Error trying to get information about dynamic linker".
5808 The gdb-6.7 release is also affected.
5810 * GDB now supports the --enable-targets= configure option to allow
5811 building a single GDB executable that supports multiple remote
5812 target architectures.
5814 * GDB now supports debugging C and C++ programs which use the
5815 Decimal Floating Point extension. In addition, the PowerPC target
5816 now has a set of pseudo-registers to inspect decimal float values
5817 stored in two consecutive float registers.
5819 * The -break-insert MI command can optionally create pending
5822 * Improved support for debugging Ada
5823 Many improvements to the Ada language support have been made. These
5825 - Better support for Ada2005 interface types
5826 - Improved handling of arrays and slices in general
5827 - Better support for Taft-amendment types
5828 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5830 - Improved command completion in Ada
5833 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5838 set print frame-arguments (all|scalars|none)
5839 show print frame-arguments
5840 The value of this variable can be changed to control which argument
5841 values should be printed by the debugger when displaying a frame.
5846 Transfer files to and from a remote target, and delete remote files.
5853 Transfer files to and from a remote target, and delete remote files.
5855 * New remote packets
5862 Open, close, read, write, and delete files on the remote system.
5865 Attach to an existing process on the remote system, in extended-remote
5869 Run a new process on the remote system, in extended-remote mode.
5871 *** Changes in GDB 6.7
5873 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5874 bfd, libiberty and opcodes, as revealed by static analysis donated by
5875 Coverity, Inc. (http://scan.coverity.com).
5877 * When looking up multiply-defined global symbols, GDB will now prefer the
5878 symbol definition in the current shared library if it was built using the
5879 -Bsymbolic linker option.
5881 * When the Text User Interface (TUI) is not configured, GDB will now
5882 recognize the -tui command-line option and print a message that the TUI
5885 * The GDB remote stub, gdbserver, now has lower overhead for high
5886 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5888 * GDB for MIPS targets now autodetects whether a remote target provides
5889 32-bit or 64-bit register values.
5891 * Support for C++ member pointers has been improved.
5893 * GDB now understands XML target descriptions, which specify the
5894 target's overall architecture. GDB can read a description from
5895 a local file or over the remote serial protocol.
5897 * Vectors of single-byte data use a new integer type which is not
5898 automatically displayed as character or string data.
5900 * The /s format now works with the print command. It displays
5901 arrays of single-byte integers and pointers to single-byte integers
5904 * Target descriptions can now describe target-specific registers,
5905 for architectures which have implemented the support (currently
5906 only ARM, M68K, and MIPS).
5908 * GDB and the GDB remote stub, gdbserver, now support the XScale
5911 * The GDB remote stub, gdbserver, has been updated to support
5912 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
5913 has been rewritten to use the standard GDB remote protocol.
5915 * GDB can now step into C++ functions which are called through thunks.
5917 * GDB for the Cell/B.E. SPU now supports overlay debugging.
5919 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
5920 layout. It also supports a TextSeg= and DataSeg= response when only
5921 segment base addresses (rather than offsets) are available.
5923 * The /i format now outputs any trailing branch delay slot instructions
5924 immediately following the last instruction within the count specified.
5926 * The GDB remote protocol "T" stop reply packet now supports a
5927 "library" response. Combined with the new "qXfer:libraries:read"
5928 packet, this response allows GDB to debug shared libraries on targets
5929 where the operating system manages the list of loaded libraries (e.g.
5930 Windows and SymbianOS).
5932 * The GDB remote stub, gdbserver, now supports dynamic link libraries
5933 (DLLs) on Windows and Windows CE targets.
5935 * GDB now supports a faster verification that a .debug file matches its binary
5936 according to its build-id signature, if the signature is present.
5942 Enable or disable hardware flow control (RTS/CTS) on the serial port
5943 when debugging using remote targets.
5945 set mem inaccessible-by-default
5946 show mem inaccessible-by-default
5947 If the target supplies a memory map, for instance via the remote
5948 protocol's "qXfer:memory-map:read" packet, setting this variable
5949 prevents GDB from accessing memory outside the memory map. This
5950 is useful for targets with memory mapped registers or which react
5951 badly to accesses of unmapped address space.
5953 set breakpoint auto-hw
5954 show breakpoint auto-hw
5955 If the target supplies a memory map, for instance via the remote
5956 protocol's "qXfer:memory-map:read" packet, setting this variable
5957 lets GDB use hardware breakpoints automatically for memory regions
5958 where it can not use software breakpoints. This covers both the
5959 "break" command and internal breakpoints used for other commands
5960 including "next" and "finish".
5963 catch exception unhandled
5964 Stop the program execution when Ada exceptions are raised.
5967 Stop the program execution when an Ada assertion failed.
5971 Set an alternate system root for target files. This is a more
5972 general version of "set solib-absolute-prefix", which is now
5973 an alias to "set sysroot".
5976 Provide extended SPU facility status information. This set of
5977 commands is available only when debugging the Cell/B.E. SPU
5980 * New native configurations
5982 OpenBSD/sh sh*-*openbsd*
5985 unset tdesc filename
5987 Use the specified local file as an XML target description, and do
5988 not query the target for its built-in description.
5992 OpenBSD/sh sh*-*-openbsd*
5993 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
5994 Toshiba Media Processor mep-elf
5996 * New remote packets
5999 Ignore the specified signals; pass them directly to the debugged program
6000 without stopping other threads or reporting them to GDB.
6002 qXfer:features:read:
6003 Read an XML target description from the target, which describes its
6008 Read or write contents of an spufs file on the target system. These
6009 packets are available only on the Cell/B.E. SPU architecture.
6011 qXfer:libraries:read:
6012 Report the loaded shared libraries. Combined with new "T" packet
6013 response, this packet allows GDB to debug shared libraries on
6014 targets where the operating system manages the list of loaded
6015 libraries (e.g. Windows and SymbianOS).
6019 Support for these obsolete configurations has been removed.
6027 i[34567]86-*-lynxos*
6028 i[34567]86-*-netware*
6029 i[34567]86-*-sco3.2v5*
6030 i[34567]86-*-sco3.2v4*
6032 i[34567]86-*-sysv4.2*
6035 i[34567]86-*-unixware2*
6036 i[34567]86-*-unixware*
6045 * Other removed features
6052 Various m68k-only ROM monitors.
6059 Various Renesas ROM monitors and debugging interfaces for SH and
6064 Support for a Macraigor serial interface to on-chip debugging.
6065 GDB does not directly support the newer parallel or USB
6070 A debug information format. The predecessor to DWARF 2 and
6071 DWARF 3, which are still supported.
6073 Support for the HP aCC compiler on HP-UX/PA-RISC
6075 SOM-encapsulated symbolic debugging information, automatic
6076 invocation of pxdb, and the aCC custom C++ ABI. This does not
6077 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6078 with aCC can still be debugged on an assembly level.
6080 MIPS ".pdr" sections
6082 A MIPS-specific format used to describe stack frame layout
6083 in debugging information.
6087 GDB could work with an older version of Guile to debug
6088 the interpreter and Scheme programs running in it.
6090 set mips stack-arg-size
6091 set mips saved-gpreg-size
6093 Use "set mips abi" to control parameter passing for MIPS.
6095 *** Changes in GDB 6.6
6100 Cell Broadband Engine SPU spu-elf
6102 * GDB can now be configured as a cross-debugger targeting native Windows
6103 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6104 running on a Windows system over TCP/IP to debug Windows programs.
6106 * The GDB remote stub, gdbserver, has been updated to support Windows and
6107 Cygwin debugging. Both single-threaded and multi-threaded programs are
6110 * The "set trust-readonly-sections" command works again. This command was
6111 broken in GDB 6.3, 6.4, and 6.5.
6113 * The "load" command now supports writing to flash memory, if the remote
6114 stub provides the required support.
6116 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
6117 longer requires symbolic debug information (e.g. DWARF-2).
6122 unset substitute-path
6123 show substitute-path
6124 Manage a list of substitution rules that GDB uses to rewrite the name
6125 of the directories where the sources are located. This can be useful
6126 for instance when the sources were moved to a different location
6127 between compilation and debugging.
6131 Print each CLI command as it is executed. Each command is prefixed with
6132 a number of `+' symbols representing the nesting depth.
6133 The source command now has a `-v' option to enable the same feature.
6137 The ARM Demon monitor support (RDP protocol, "target rdp").
6139 Kernel Object Display, an embedded debugging feature which only worked with
6140 an obsolete version of Cisco IOS.
6142 The 'set download-write-size' and 'show download-write-size' commands.
6144 * New remote packets
6147 Tell a stub about GDB client features, and request remote target features.
6148 The first feature implemented is PacketSize, which allows the target to
6149 specify the size of packets it can handle - to minimize the number of
6150 packets required and improve performance when connected to a remote
6154 Fetch an OS auxilliary vector from the remote stub. This packet is a
6155 more efficient replacement for qPart:auxv:read.
6157 qXfer:memory-map:read:
6158 Fetch a memory map from the remote stub, including information about
6159 RAM, ROM, and flash memory devices.
6164 Erase and program a flash memory device.
6166 * Removed remote packets
6169 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
6170 used it, and only gdbserver implemented it.
6172 *** Changes in GDB 6.5
6176 Renesas M32C/M16C m32c-elf
6178 Morpho Technologies ms1 ms1-elf
6182 init-if-undefined Initialize a convenience variable, but
6183 only if it doesn't already have a value.
6185 The following commands are presently only implemented for native GNU/Linux:
6187 checkpoint Save a snapshot of the program state.
6189 restart <n> Return the program state to a
6190 previously saved state.
6192 info checkpoints List currently saved checkpoints.
6194 delete-checkpoint <n> Delete a previously saved checkpoint.
6196 set|show detach-on-fork Tell gdb whether to detach from a newly
6197 forked process, or to keep debugging it.
6199 info forks List forks of the user program that
6200 are available to be debugged.
6202 fork <n> Switch to debugging one of several
6203 forks of the user program that are
6204 available to be debugged.
6206 delete-fork <n> Delete a fork from the list of forks
6207 that are available to be debugged (and
6208 kill the forked process).
6210 detach-fork <n> Delete a fork from the list of forks
6211 that are available to be debugged (and
6212 allow the process to continue).
6216 Morpho Technologies ms2 ms1-elf
6218 * Improved Windows host support
6220 GDB now builds as a cross debugger hosted on i686-mingw32, including
6221 native console support, and remote communications using either
6222 network sockets or serial ports.
6224 * Improved Modula-2 language support
6226 GDB can now print most types in the Modula-2 syntax. This includes:
6227 basic types, set types, record types, enumerated types, range types,
6228 pointer types and ARRAY types. Procedure var parameters are correctly
6229 printed and hexadecimal addresses and character constants are also
6230 written in the Modula-2 syntax. Best results can be obtained by using
6231 GNU Modula-2 together with the -gdwarf-2 command line option.
6235 The ARM rdi-share module.
6237 The Netware NLM debug server.
6239 *** Changes in GDB 6.4
6241 * New native configurations
6243 OpenBSD/arm arm*-*-openbsd*
6244 OpenBSD/mips64 mips64-*-openbsd*
6248 Morpho Technologies ms1 ms1-elf
6250 * New command line options
6252 --batch-silent As for --batch, but totally silent.
6253 --return-child-result The debugger will exist with the same value
6254 the child (debugged) program exited with.
6255 --eval-command COMMAND, -ex COMMAND
6256 Execute a single GDB CLI command. This may be
6257 specified multiple times and in conjunction
6258 with the --command (-x) option.
6260 * Deprecated commands removed
6262 The following commands, that were deprecated in 2000, have been
6266 set|show arm disassembly-flavor set|show arm disassembler
6267 othernames set arm disassembler
6268 set|show remotedebug set|show debug remote
6269 set|show archdebug set|show debug arch
6270 set|show eventdebug set|show debug event
6273 * New BSD user-level threads support
6275 It is now possible to debug programs using the user-level threads
6276 library on OpenBSD and FreeBSD. Currently supported (target)
6279 FreeBSD/amd64 x86_64-*-freebsd*
6280 FreeBSD/i386 i386-*-freebsd*
6281 OpenBSD/i386 i386-*-openbsd*
6283 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6284 are not yet supported.
6286 * New support for Matsushita MN10300 w/sim added
6287 (Work in progress). mn10300-elf.
6289 * REMOVED configurations and files
6291 VxWorks and the XDR protocol *-*-vxworks
6292 Motorola MCORE mcore-*-*
6293 National Semiconductor NS32000 ns32k-*-*
6295 * New "set print array-indexes" command
6297 After turning this setting "on", GDB prints the index of each element
6298 when displaying arrays. The default is "off" to preserve the previous
6301 * VAX floating point support
6303 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6305 * User-defined command support
6307 In addition to using $arg0..$arg9 for argument passing, it is now possible
6308 to use $argc to determine now many arguments have been passed. See the
6309 section on user-defined commands in the user manual for more information.
6311 *** Changes in GDB 6.3:
6313 * New command line option
6315 GDB now accepts -l followed by a number to set the timeout for remote
6318 * GDB works with GCC -feliminate-dwarf2-dups
6320 GDB now supports a more compact representation of DWARF-2 debug
6321 information using DW_FORM_ref_addr references. These are produced
6322 by GCC with the option -feliminate-dwarf2-dups and also by some
6323 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6324 to use -feliminate-dwarf2-dups.
6326 * Internationalization
6328 When supported by the host system, GDB will be built with
6329 internationalization (libintl). The task of marking up the sources is
6330 continued, we're looking forward to our first translation.
6334 Initial support for debugging programs compiled with the GNAT
6335 implementation of the Ada programming language has been integrated
6336 into GDB. In this release, support is limited to expression evaluation.
6338 * New native configurations
6340 GNU/Linux/m32r m32r-*-linux-gnu
6344 GDB's remote protocol now includes support for the 'p' packet. This
6345 packet is used to fetch individual registers from a remote inferior.
6347 * END-OF-LIFE registers[] compatibility module
6349 GDB's internal register infrastructure has been completely rewritten.
6350 The new infrastructure making possible the implementation of key new
6351 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6354 GDB 6.3 will be the last release to include the registers[]
6355 compatibility module that allowed out-of-date configurations to
6356 continue to work. This change directly impacts the following
6366 powerpc bdm protocol
6368 Unless there is activity to revive these configurations, they will be
6369 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6371 * OBSOLETE configurations and files
6373 Configurations that have been declared obsolete in this release have
6374 been commented out. Unless there is activity to revive these
6375 configurations, the next release of GDB will have their sources
6376 permanently REMOVED.
6385 *** Changes in GDB 6.2.1:
6387 * MIPS `break main; run' gave an heuristic-fence-post warning
6389 When attempting to run even a simple program, a warning about
6390 heuristic-fence-post being hit would be reported. This problem has
6393 * MIPS IRIX 'long double' crashed GDB
6395 When examining a long double variable, GDB would get a segmentation
6396 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6397 IRIX long double values).
6401 A bug in the VAX stack code was causing problems with the "next"
6402 command. This problem has been fixed.
6404 *** Changes in GDB 6.2:
6406 * Fix for ``many threads''
6408 On GNU/Linux systems that use the NPTL threads library, a program
6409 rapidly creating and deleting threads would confuse GDB leading to the
6412 ptrace: No such process.
6413 thread_db_get_info: cannot get thread info: generic error
6415 This problem has been fixed.
6417 * "-async" and "-noasync" options removed.
6419 Support for the broken "-noasync" option has been removed (it caused
6422 * New ``start'' command.
6424 This command runs the program until the beginning of the main procedure.
6426 * New BSD Kernel Data Access Library (libkvm) interface
6428 Using ``target kvm'' it is now possible to debug kernel core dumps and
6429 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6430 platforms. Currently supported (native-only) configurations are:
6432 FreeBSD/amd64 x86_64-*-freebsd*
6433 FreeBSD/i386 i?86-*-freebsd*
6434 NetBSD/i386 i?86-*-netbsd*
6435 NetBSD/m68k m68*-*-netbsd*
6436 NetBSD/sparc sparc-*-netbsd*
6437 OpenBSD/amd64 x86_64-*-openbsd*
6438 OpenBSD/i386 i?86-*-openbsd*
6439 OpenBSD/m68k m68*-openbsd*
6440 OpenBSD/sparc sparc-*-openbsd*
6442 * Signal trampoline code overhauled
6444 Many generic problems with GDB's signal handling code have been fixed.
6445 These include: backtraces through non-contiguous stacks; recognition
6446 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6447 call; backtrace through a signal trampoline; step into and out of
6448 signal handlers; and single-stepping in the signal trampoline.
6450 Please note that kernel bugs are a limiting factor here. These
6451 features have been shown to work on an s390 GNU/Linux system that
6452 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6454 * Cygwin support for DWARF 2 added.
6456 * New native configurations
6458 GNU/Linux/hppa hppa*-*-linux*
6459 OpenBSD/hppa hppa*-*-openbsd*
6460 OpenBSD/m68k m68*-*-openbsd*
6461 OpenBSD/m88k m88*-*-openbsd*
6462 OpenBSD/powerpc powerpc-*-openbsd*
6463 NetBSD/vax vax-*-netbsd*
6464 OpenBSD/vax vax-*-openbsd*
6466 * END-OF-LIFE frame compatibility module
6468 GDB's internal frame infrastructure has been completely rewritten.
6469 The new infrastructure making it possible to support key new features
6470 including DWARF 2 Call Frame Information. To aid in the task of
6471 migrating old configurations to this new infrastructure, a
6472 compatibility module, that allowed old configurations to continue to
6473 work, was also included.
6475 GDB 6.2 will be the last release to include this frame compatibility
6476 module. This change directly impacts the following configurations:
6486 Unless there is activity to revive these configurations, they will be
6487 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6489 * REMOVED configurations and files
6491 Sun 3, running SunOS 3 m68*-*-sunos3*
6492 Sun 3, running SunOS 4 m68*-*-sunos4*
6493 Sun 2, running SunOS 3 m68000-*-sunos3*
6494 Sun 2, running SunOS 4 m68000-*-sunos4*
6495 Motorola 680x0 running LynxOS m68*-*-lynxos*
6496 AT&T 3b1/Unix pc m68*-att-*
6497 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6498 decstation mips-dec-* mips-little-*
6499 riscos mips-*-riscos* mips-*-sysv*
6500 sonymips mips-sony-*
6501 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6503 *** Changes in GDB 6.1.1:
6505 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6507 The TUI (Text-mode User Interface) is now built as part of a default
6508 GDB configuration. It is enabled by either selecting the TUI with the
6509 command line option "-i=tui" or by running the separate "gdbtui"
6510 program. For more information on the TUI, see the manual "Debugging
6513 * Pending breakpoint support (also included in GDB 6.1)
6515 Support has been added to allow you to specify breakpoints in shared
6516 libraries that have not yet been loaded. If a breakpoint location
6517 cannot be found, and the "breakpoint pending" option is set to auto,
6518 GDB queries you if you wish to make the breakpoint pending on a future
6519 shared-library load. If and when GDB resolves the breakpoint symbol,
6520 the pending breakpoint is removed as one or more regular breakpoints
6523 Pending breakpoints are very useful for GCJ Java debugging.
6525 * Fixed ISO-C build problems
6527 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6528 non ISO-C code that stopped them being built using a more strict ISO-C
6529 compiler (e.g., IBM's C compiler).
6531 * Fixed build problem on IRIX 5
6533 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6534 wasn't able to compile compile on an IRIX 5 system.
6536 * Added execute permission to gdb/gdbserver/configure
6538 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6539 permission. This bug would cause configure to fail on a number of
6540 systems (Solaris, IRIX). Ref: server/519.
6542 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6544 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6545 has been updated to use constant array sizes.
6547 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6549 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6550 its generated DWARF Call Frame Info. This encoding was causing GDB to
6551 panic, that panic has been fixed. Ref: gdb/1628.
6553 * Fixed a problem when examining parameters in shared library code.
6555 When examining parameters in optimized shared library code generated
6556 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6557 not available''. GDB now correctly displays the variable's value.
6559 *** Changes in GDB 6.1:
6561 * Removed --with-mmalloc
6563 Support for the mmalloc memory manager has been removed, as it
6564 conflicted with the internal gdb byte cache.
6566 * Changes in AMD64 configurations
6568 The AMD64 target now includes the %cs and %ss registers. As a result
6569 the AMD64 remote protocol has changed; this affects the floating-point
6570 and SSE registers. If you rely on those registers for your debugging,
6571 you should upgrade gdbserver on the remote side.
6573 * Revised SPARC target
6575 The SPARC target has been completely revised, incorporating the
6576 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6577 support for LynxOS and SunOS 4 has been dropped. Calling functions
6578 from within GDB on operating systems with a non-executable stack
6579 (Solaris, OpenBSD) now works.
6583 GDB has a new C++ demangler which does a better job on the mangled
6584 names generated by current versions of g++. It also runs faster, so
6585 with this and other changes gdb should now start faster on large C++
6588 * DWARF 2 Location Expressions
6590 GDB support for location expressions has been extended to support function
6591 arguments and frame bases. Older versions of GDB could crash when they
6594 * C++ nested types and namespaces
6596 GDB's support for nested types and namespaces in C++ has been
6597 improved, especially if you use the DWARF 2 debugging format. (This
6598 is the default for recent versions of GCC on most platforms.)
6599 Specifically, if you have a class "Inner" defined within a class or
6600 namespace "Outer", then GDB realizes that the class's name is
6601 "Outer::Inner", not simply "Inner". This should greatly reduce the
6602 frequency of complaints about not finding RTTI symbols. In addition,
6603 if you are stopped at inside of a function defined within a namespace,
6604 GDB modifies its name lookup accordingly.
6606 * New native configurations
6608 NetBSD/amd64 x86_64-*-netbsd*
6609 OpenBSD/amd64 x86_64-*-openbsd*
6610 OpenBSD/alpha alpha*-*-openbsd*
6611 OpenBSD/sparc sparc-*-openbsd*
6612 OpenBSD/sparc64 sparc64-*-openbsd*
6614 * New debugging protocols
6616 M32R with SDI protocol m32r-*-elf*
6618 * "set prompt-escape-char" command deleted.
6620 The command "set prompt-escape-char" has been deleted. This command,
6621 and its very obscure effect on GDB's prompt, was never documented,
6622 tested, nor mentioned in the NEWS file.
6624 * OBSOLETE configurations and files
6626 Configurations that have been declared obsolete in this release have
6627 been commented out. Unless there is activity to revive these
6628 configurations, the next release of GDB will have their sources
6629 permanently REMOVED.
6631 Sun 3, running SunOS 3 m68*-*-sunos3*
6632 Sun 3, running SunOS 4 m68*-*-sunos4*
6633 Sun 2, running SunOS 3 m68000-*-sunos3*
6634 Sun 2, running SunOS 4 m68000-*-sunos4*
6635 Motorola 680x0 running LynxOS m68*-*-lynxos*
6636 AT&T 3b1/Unix pc m68*-att-*
6637 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6638 decstation mips-dec-* mips-little-*
6639 riscos mips-*-riscos* mips-*-sysv*
6640 sonymips mips-sony-*
6641 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6643 * REMOVED configurations and files
6645 SGI Irix-4.x mips-sgi-irix4 or iris4
6646 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6647 Z8000 simulator z8k-zilog-none or z8ksim
6648 Matsushita MN10200 w/simulator mn10200-*-*
6649 H8/500 simulator h8500-hitachi-hms or h8500hms
6650 HP/PA running BSD hppa*-*-bsd*
6651 HP/PA running OSF/1 hppa*-*-osf*
6652 HP/PA Pro target hppa*-*-pro*
6653 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6654 386BSD i[3456]86-*-bsd*
6655 Sequent family i[3456]86-sequent-sysv4*
6656 i[3456]86-sequent-sysv*
6657 i[3456]86-sequent-bsd*
6658 SPARC running LynxOS sparc-*-lynxos*
6659 SPARC running SunOS 4 sparc-*-sunos4*
6660 Tsqware Sparclet sparclet-*-*
6661 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6663 *** Changes in GDB 6.0:
6667 Support for debugging the Objective-C programming language has been
6668 integrated into GDB.
6670 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6672 DWARF 2's Call Frame Information makes available compiler generated
6673 information that more exactly describes the program's run-time stack.
6674 By using this information, GDB is able to provide more robust stack
6677 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6678 have been updated to use a new backtrace mechanism which includes
6679 DWARF 2 CFI support.
6683 GDB's remote protocol has been extended to include support for hosted
6684 file I/O (where the remote target uses GDB's file system). See GDB's
6685 remote protocol documentation for details.
6687 * All targets using the new architecture framework.
6689 All of GDB's targets have been updated to use the new internal
6690 architecture framework. The way is now open for future GDB releases
6691 to include cross-architecture native debugging support (i386 on amd64,
6694 * GNU/Linux's Thread Local Storage (TLS)
6696 GDB now includes support for for the GNU/Linux implementation of
6697 per-thread variables.
6699 * GNU/Linux's Native POSIX Thread Library (NPTL)
6701 GDB's thread code has been updated to work with either the new
6702 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6704 * Separate debug info.
6706 GDB, in conjunction with BINUTILS, now supports a mechanism for
6707 automatically loading debug information from a separate file. Instead
6708 of shipping full debug and non-debug versions of system libraries,
6709 system integrators can now instead ship just the stripped libraries
6710 and optional debug files.
6712 * DWARF 2 Location Expressions
6714 DWARF 2 Location Expressions allow the compiler to more completely
6715 describe the location of variables (even in optimized code) to the
6718 GDB now includes preliminary support for location expressions (support
6719 for DW_OP_piece is still missing).
6723 A number of long standing bugs that caused GDB to die while starting a
6724 Java application have been fixed. GDB's Java support is now
6725 considered "useable".
6727 * GNU/Linux support for fork, vfork, and exec.
6729 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6730 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6733 * GDB supports logging output to a file
6735 There are two new commands, "set logging" and "show logging", which can be
6736 used to capture GDB's output to a file.
6738 * The meaning of "detach" has changed for gdbserver
6740 The "detach" command will now resume the application, as documented. To
6741 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6744 * d10v, m68hc11 `regs' command deprecated
6746 The `info registers' command has been updated so that it displays the
6747 registers using a format identical to the old `regs' command.
6751 A new command, "maint set profile on/off", has been added. This command can
6752 be used to enable or disable profiling while running GDB, to profile a
6753 session or a set of commands. In addition there is a new configure switch,
6754 "--enable-profiling", which will cause GDB to be compiled with profiling
6755 data, for more informative profiling results.
6757 * Default MI syntax changed to "mi2".
6759 The default MI (machine interface) syntax, enabled by the command line
6760 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6761 "mi1", can be enabled by specifying the option "-i=mi1".
6763 Support for the original "mi0" syntax (included in GDB 5.0) has been
6766 Fix for gdb/192: removed extraneous space when displaying frame level.
6767 Fix for gdb/672: update changelist is now output in mi list format.
6768 Fix for gdb/702: a -var-assign that updates the value now shows up
6769 in a subsequent -var-update.
6771 * New native configurations.
6773 FreeBSD/amd64 x86_64-*-freebsd*
6775 * Multi-arched targets.
6777 HP/PA HPUX11 hppa*-*-hpux*
6778 Renesas M32R/D w/simulator m32r-*-elf*
6780 * OBSOLETE configurations and files
6782 Configurations that have been declared obsolete in this release have
6783 been commented out. Unless there is activity to revive these
6784 configurations, the next release of GDB will have their sources
6785 permanently REMOVED.
6787 Z8000 simulator z8k-zilog-none or z8ksim
6788 Matsushita MN10200 w/simulator mn10200-*-*
6789 H8/500 simulator h8500-hitachi-hms or h8500hms
6790 HP/PA running BSD hppa*-*-bsd*
6791 HP/PA running OSF/1 hppa*-*-osf*
6792 HP/PA Pro target hppa*-*-pro*
6793 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6794 Sequent family i[3456]86-sequent-sysv4*
6795 i[3456]86-sequent-sysv*
6796 i[3456]86-sequent-bsd*
6797 Tsqware Sparclet sparclet-*-*
6798 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6800 * REMOVED configurations and files
6803 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6804 IBM AIX PS/2 i[3456]86-*-aix
6805 i386 running Mach 3.0 i[3456]86-*-mach3*
6806 i386 running Mach i[3456]86-*-mach*
6807 i386 running OSF/1 i[3456]86-*osf1mk*
6808 HP/Apollo 68k Family m68*-apollo*-sysv*,
6810 m68*-hp-bsd*, m68*-hp-hpux*
6811 Argonaut Risc Chip (ARC) arc-*-*
6812 Mitsubishi D30V d30v-*-*
6813 Fujitsu FR30 fr30-*-elf*
6814 OS/9000 i[34]86-*-os9k
6815 I960 with MON960 i960-*-coff
6817 * MIPS $fp behavior changed
6819 The convenience variable $fp, for the MIPS, now consistently returns
6820 the address of the current frame's base. Previously, depending on the
6821 context, $fp could refer to either $sp or the current frame's base
6822 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6823 The GNU Source-Level Debugger''.
6825 *** Changes in GDB 5.3:
6827 * GNU/Linux shared library multi-threaded performance improved.
6829 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6830 `/proc', in preference to `ptrace' for memory reads. This may result
6831 in an improvement in the start-up time of multi-threaded, shared
6832 library applications when run under GDB. One GDB user writes: ``loads
6833 shared libs like mad''.
6835 * ``gdbserver'' now supports multi-threaded applications on some targets
6837 Support for debugging multi-threaded applications which use
6838 the GNU/Linux LinuxThreads package has been added for
6839 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6840 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6842 * GDB now supports C/C++ preprocessor macros.
6844 GDB now expands preprocessor macro invocations in C/C++ expressions,
6845 and provides various commands for showing macro definitions and how
6848 The new command `macro expand EXPRESSION' expands any macro
6849 invocations in expression, and shows the result.
6851 The new command `show macro MACRO-NAME' shows the definition of the
6852 macro named MACRO-NAME, and where it was defined.
6854 Most compilers don't include information about macros in the debugging
6855 information by default. In GCC 3.1, for example, you need to compile
6856 your program with the options `-gdwarf-2 -g3'. If the macro
6857 information is present in the executable, GDB will read it.
6859 * Multi-arched targets.
6861 DEC Alpha (partial) alpha*-*-*
6862 DEC VAX (partial) vax-*-*
6864 National Semiconductor NS32000 (partial) ns32k-*-*
6865 Motorola 68000 (partial) m68k-*-*
6866 Motorola MCORE mcore-*-*
6870 Fujitsu FRV architecture added by Red Hat frv*-*-*
6873 * New native configurations
6875 Alpha NetBSD alpha*-*-netbsd*
6876 SH NetBSD sh*-*-netbsdelf*
6877 MIPS NetBSD mips*-*-netbsd*
6878 UltraSPARC NetBSD sparc64-*-netbsd*
6880 * OBSOLETE configurations and files
6882 Configurations that have been declared obsolete in this release have
6883 been commented out. Unless there is activity to revive these
6884 configurations, the next release of GDB will have their sources
6885 permanently REMOVED.
6887 Mitsubishi D30V d30v-*-*
6888 OS/9000 i[34]86-*-os9k
6889 IBM AIX PS/2 i[3456]86-*-aix
6890 Fujitsu FR30 fr30-*-elf*
6891 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6892 Argonaut Risc Chip (ARC) arc-*-*
6893 i386 running Mach 3.0 i[3456]86-*-mach3*
6894 i386 running Mach i[3456]86-*-mach*
6895 i386 running OSF/1 i[3456]86-*osf1mk*
6896 HP/Apollo 68k Family m68*-apollo*-sysv*,
6898 m68*-hp-bsd*, m68*-hp-hpux*
6899 I960 with MON960 i960-*-coff
6901 * OBSOLETE languages
6903 CHILL, a Pascal like language used by telecommunications companies.
6905 * REMOVED configurations and files
6907 AMD 29k family via UDI a29k-amd-udi, udi29k
6908 A29K VxWorks a29k-*-vxworks
6909 AMD 29000 embedded, using EBMON a29k-none-none
6910 AMD 29000 embedded with COFF a29k-none-coff
6911 AMD 29000 embedded with a.out a29k-none-aout
6913 testsuite/gdb.hp/gdb.threads-hp/ directory
6915 * New command "set max-user-call-depth <nnn>"
6917 This command allows the user to limit the call depth of user-defined
6918 commands. The default is 1024.
6920 * Changes in FreeBSD/i386 native debugging.
6922 Support for the "generate-core-file" has been added.
6924 * New commands "dump", "append", and "restore".
6926 These commands allow data to be copied from target memory
6927 to a bfd-format or binary file (dump and append), and back
6928 from a file into memory (restore).
6930 * Improved "next/step" support on multi-processor Alpha Tru64.
6932 The previous single-step mechanism could cause unpredictable problems,
6933 including the random appearance of SIGSEGV or SIGTRAP signals. The use
6934 of a software single-step mechanism prevents this.
6936 *** Changes in GDB 5.2.1:
6944 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
6945 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
6946 Fix, by Joel Brobecker imported from mainline.
6948 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
6949 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
6950 Fix, by Fred Fish, imported from mainline.
6952 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
6953 Surprisingly enough, it works now.
6954 By Michal Ludvig, imported from mainline.
6956 i386 hardware watchpoint support:
6957 avoid misses on second run for some targets.
6958 By Pierre Muller, imported from mainline.
6960 *** Changes in GDB 5.2:
6962 * New command "set trust-readonly-sections on[off]".
6964 This command is a hint that tells gdb that read-only sections
6965 really are read-only (ie. that their contents will not change).
6966 In this mode, gdb will go to the object file rather than the
6967 target to read memory from read-only sections (such as ".text").
6968 This can be a significant performance improvement on some
6969 (notably embedded) targets.
6971 * New command "generate-core-file" (or "gcore").
6973 This new gdb command allows the user to drop a core file of the child
6974 process state at any time. So far it's been implemented only for
6975 GNU/Linux and Solaris, but should be relatively easily ported to other
6976 hosts. Argument is core file name (defaults to core.<pid>).
6978 * New command line option
6980 GDB now accepts --pid or -p followed by a process id.
6982 * Change in command line behavior -- corefiles vs. process ids.
6984 There is a subtle behavior in the way in which GDB handles
6985 command line arguments. The first non-flag argument is always
6986 a program to debug, but the second non-flag argument may either
6987 be a corefile or a process id. Previously, GDB would attempt to
6988 open the second argument as a corefile, and if that failed, would
6989 issue a superfluous error message and then attempt to attach it as
6990 a process. Now, if the second argument begins with a non-digit,
6991 it will be treated as a corefile. If it begins with a digit,
6992 GDB will attempt to attach it as a process, and if no such process
6993 is found, will then attempt to open it as a corefile.
6995 * Changes in ARM configurations.
6997 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
6998 configuration is fully multi-arch.
7000 * New native configurations
7002 ARM NetBSD arm*-*-netbsd*
7003 x86 OpenBSD i[3456]86-*-openbsd*
7004 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7005 Sparc64 running FreeBSD sparc64-*-freebsd*
7009 Sanyo XStormy16 xstormy16-elf
7011 * OBSOLETE configurations and files
7013 Configurations that have been declared obsolete in this release have
7014 been commented out. Unless there is activity to revive these
7015 configurations, the next release of GDB will have their sources
7016 permanently REMOVED.
7018 AMD 29k family via UDI a29k-amd-udi, udi29k
7019 A29K VxWorks a29k-*-vxworks
7020 AMD 29000 embedded, using EBMON a29k-none-none
7021 AMD 29000 embedded with COFF a29k-none-coff
7022 AMD 29000 embedded with a.out a29k-none-aout
7024 testsuite/gdb.hp/gdb.threads-hp/ directory
7026 * REMOVED configurations and files
7028 TI TMS320C80 tic80-*-*
7030 PowerPC Solaris powerpcle-*-solaris*
7031 PowerPC Windows NT powerpcle-*-cygwin32
7032 PowerPC Netware powerpc-*-netware*
7033 Harris/CXUX m88k m88*-harris-cxux*
7034 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7035 ns32k-utek-sysv* ns32k-utek-*
7036 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7037 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7038 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7039 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7040 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7042 * Changes to command line processing
7044 The new `--args' feature can be used to specify command-line arguments
7045 for the inferior from gdb's command line.
7047 * Changes to key bindings
7049 There is a new `operate-and-get-next' function bound to `C-o'.
7051 *** Changes in GDB 5.1.1
7053 Fix compile problem on DJGPP.
7055 Fix a problem with floating-point registers on the i386 being
7058 Fix to stop GDB crashing on .debug_str debug info.
7060 Numerous documentation fixes.
7062 Numerous testsuite fixes.
7064 *** Changes in GDB 5.1:
7066 * New native configurations
7068 Alpha FreeBSD alpha*-*-freebsd*
7069 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7070 MIPS GNU/Linux mips*-*-linux*
7071 MIPS SGI Irix 6.x mips*-sgi-irix6*
7072 ia64 AIX ia64-*-aix*
7073 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7077 Motorola 68HC11 and 68HC12 m68hc11-elf
7079 UltraSparc running GNU/Linux sparc64-*-linux*
7081 * OBSOLETE configurations and files
7083 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7084 Harris/CXUX m88k m88*-harris-cxux*
7085 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7086 ns32k-utek-sysv* ns32k-utek-*
7087 TI TMS320C80 tic80-*-*
7089 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7090 PowerPC Solaris powerpcle-*-solaris*
7091 PowerPC Windows NT powerpcle-*-cygwin32
7092 PowerPC Netware powerpc-*-netware*
7093 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7094 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7095 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7096 Apple Macintosh (MPW) host N/A
7098 stuff.c (Program to stuff files into a specially prepared space in kdb)
7099 kdb-start.c (Main loop for the standalone kernel debugger)
7101 Configurations that have been declared obsolete in this release have
7102 been commented out. Unless there is activity to revive these
7103 configurations, the next release of GDB will have their sources
7104 permanently REMOVED.
7106 * REMOVED configurations and files
7108 Altos 3068 m68*-altos-*
7109 Convex c1-*-*, c2-*-*
7111 ARM RISCix arm-*-* (as host)
7115 * GDB has been converted to ISO C.
7117 GDB's source code has been converted to ISO C. In particular, the
7118 sources are fully protoized, and rely on standard headers being
7123 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
7125 * The MI enabled by default.
7127 The new machine oriented interface (MI) introduced in GDB 5.0 has been
7128 revised and enabled by default. Packages which use GDB as a debugging
7129 engine behind a UI or another front end are encouraged to switch to
7130 using the GDB/MI interface, instead of the old annotations interface
7131 which is now deprecated.
7133 * Support for debugging Pascal programs.
7135 GDB now includes support for debugging Pascal programs. The following
7136 main features are supported:
7138 - Pascal-specific data types such as sets;
7140 - automatic recognition of Pascal sources based on file-name
7143 - Pascal-style display of data types, variables, and functions;
7145 - a Pascal expression parser.
7147 However, some important features are not yet supported.
7149 - Pascal string operations are not supported at all;
7151 - there are some problems with boolean types;
7153 - Pascal type hexadecimal constants are not supported
7154 because they conflict with the internal variables format;
7156 - support for Pascal objects and classes is not full yet;
7158 - unlike Pascal, GDB is case-sensitive for symbol names.
7160 * Changes in completion.
7162 Commands such as `shell', `run' and `set args', which pass arguments
7163 to inferior programs, now complete on file names, similar to what
7164 users expect at the shell prompt.
7166 Commands which accept locations, such as `disassemble', `print',
7167 `breakpoint', `until', etc. now complete on filenames as well as
7168 program symbols. Thus, if you type "break foob TAB", and the source
7169 files linked into the programs include `foobar.c', that file name will
7170 be one of the candidates for completion. However, file names are not
7171 considered for completion after you typed a colon that delimits a file
7172 name from a name of a function in that file, as in "break foo.c:bar".
7174 `set demangle-style' completes on available demangling styles.
7176 * New platform-independent commands:
7178 It is now possible to define a post-hook for a command as well as a
7179 hook that runs before the command. For more details, see the
7180 documentation of `hookpost' in the GDB manual.
7182 * Changes in GNU/Linux native debugging.
7184 Support for debugging multi-threaded programs has been completely
7185 revised for all platforms except m68k and sparc. You can now debug as
7186 many threads as your system allows you to have.
7188 Attach/detach is supported for multi-threaded programs.
7190 Support for SSE registers was added for x86. This doesn't work for
7191 multi-threaded programs though.
7193 * Changes in MIPS configurations.
7195 Multi-arch support is enabled for all MIPS configurations.
7197 GDB can now be built as native debugger on SGI Irix 6.x systems for
7198 debugging n32 executables. (Debugging 64-bit executables is not yet
7201 * Unified support for hardware watchpoints in all x86 configurations.
7203 Most (if not all) native x86 configurations support hardware-assisted
7204 breakpoints and watchpoints in a unified manner. This support
7205 implements debug register sharing between watchpoints, which allows to
7206 put a virtually infinite number of watchpoints on the same address,
7207 and also supports watching regions up to 16 bytes with several debug
7210 The new maintenance command `maintenance show-debug-regs' toggles
7211 debugging print-outs in functions that insert, remove, and test
7212 watchpoints and hardware breakpoints.
7214 * Changes in the DJGPP native configuration.
7216 New command ``info dos sysinfo'' displays assorted information about
7217 the CPU, OS, memory, and DPMI server.
7219 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
7220 display information about segment descriptors stored in GDT, LDT, and
7223 New commands ``info dos pde'' and ``info dos pte'' display entries
7224 from Page Directory and Page Tables (for now works with CWSDPMI only).
7225 New command ``info dos address-pte'' displays the Page Table entry for
7226 a given linear address.
7228 GDB can now pass command lines longer than 126 characters to the
7229 program being debugged (requires an update to the libdbg.a library
7230 which is part of the DJGPP development kit).
7232 DWARF2 debug info is now supported.
7234 It is now possible to `step' and `next' through calls to `longjmp'.
7236 * Changes in documentation.
7238 All GDB documentation was converted to GFDL, the GNU Free
7239 Documentation License.
7241 Tracepoints-related commands are now fully documented in the GDB
7244 TUI, the Text-mode User Interface, is now documented in the manual.
7246 Tracepoints-related commands are now fully documented in the GDB
7249 The "GDB Internals" manual now has an index. It also includes
7250 documentation of `ui_out' functions, GDB coding standards, x86
7251 hardware watchpoints, and memory region attributes.
7253 * GDB's version number moved to ``version.in''
7255 The Makefile variable VERSION has been replaced by the file
7256 ``version.in''. People creating GDB distributions should update the
7257 contents of this file.
7261 GUD support is now a standard part of the EMACS distribution.
7263 *** Changes in GDB 5.0:
7265 * Improved support for debugging FP programs on x86 targets
7267 Unified and much-improved support for debugging floating-point
7268 programs on all x86 targets. In particular, ``info float'' now
7269 displays the FP registers in the same format on all x86 targets, with
7270 greater level of detail.
7272 * Improvements and bugfixes in hardware-assisted watchpoints
7274 It is now possible to watch array elements, struct members, and
7275 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7276 on x86 targets no longer erroneously trigger when the address is
7279 * Improvements in the native DJGPP version of GDB
7281 The distribution now includes all the scripts and auxiliary files
7282 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7283 machines ``out of the box''.
7285 The DJGPP version can now debug programs that use signals. It is
7286 possible to catch signals that happened in the debuggee, deliver
7287 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7288 would kill the program being debugged.) Programs that hook hardware
7289 interrupts (keyboard, timer, etc.) can also be debugged.
7291 It is now possible to debug DJGPP programs that redirect their
7292 standard handles or switch them to raw (as opposed to cooked) mode, or
7293 even close them. The command ``run < foo > bar'' works as expected,
7294 and ``info terminal'' reports useful information about the debuggee's
7295 terminal, including raw/cooked mode, redirection, etc.
7297 The DJGPP version now uses termios functions for console I/O, which
7298 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7301 DOS-style file names with drive letters are now fully supported by
7304 It is now possible to debug DJGPP programs that switch their working
7305 directory. It is also possible to rerun the debuggee any number of
7306 times without restarting GDB; thus, you can use the same setup,
7307 breakpoints, etc. for many debugging sessions.
7309 * New native configurations
7311 ARM GNU/Linux arm*-*-linux*
7312 PowerPC GNU/Linux powerpc-*-linux*
7316 Motorola MCore mcore-*-*
7317 x86 VxWorks i[3456]86-*-vxworks*
7318 PowerPC VxWorks powerpc-*-vxworks*
7319 TI TMS320C80 tic80-*-*
7321 * OBSOLETE configurations
7323 Altos 3068 m68*-altos-*
7324 Convex c1-*-*, c2-*-*
7326 ARM RISCix arm-*-* (as host)
7329 Configurations that have been declared obsolete will be commented out,
7330 but the code will be left in place. If there is no activity to revive
7331 these configurations before the next release of GDB, the sources will
7332 be permanently REMOVED.
7334 * Gould support removed
7336 Support for the Gould PowerNode and NP1 has been removed.
7338 * New features for SVR4
7340 On SVR4 native platforms (such as Solaris), if you attach to a process
7341 without first loading a symbol file, GDB will now attempt to locate and
7342 load symbols from the running process's executable file.
7344 * Many C++ enhancements
7346 C++ support has been greatly improved. Overload resolution now works properly
7347 in almost all cases. RTTI support is on the way.
7349 * Remote targets can connect to a sub-program
7351 A popen(3) style serial-device has been added. This device starts a
7352 sub-process (such as a stand-alone simulator) and then communicates
7353 with that. The sub-program to run is specified using the syntax
7354 ``|<program> <args>'' vis:
7356 (gdb) set remotedebug 1
7357 (gdb) target extended-remote |mn10300-elf-sim program-args
7359 * MIPS 64 remote protocol
7361 A long standing bug in the mips64 remote protocol where by GDB
7362 expected certain 32 bit registers (ex SR) to be transfered as 32
7363 instead of 64 bits has been fixed.
7365 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7366 added to provide backward compatibility with older versions of GDB.
7368 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7370 The command ``set remotebinarydownload'' command has been replaced by
7371 ``set remote X-packet''. Other commands in ``set remote'' family
7372 include ``set remote P-packet''.
7374 * Breakpoint commands accept ranges.
7376 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7377 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7378 ``tracepoint passcount'' also accepts a range of tracepoints.
7380 * ``apropos'' command added.
7382 The ``apropos'' command searches through command names and
7383 documentation strings, printing out matches, making it much easier to
7384 try to find a command that does what you are looking for.
7388 A new machine oriented interface (MI) has been added to GDB. This
7389 interface is designed for debug environments running GDB as a separate
7390 process. This is part of the long term libGDB project. See the
7391 "GDB/MI" chapter of the GDB manual for further information. It can be
7392 enabled by configuring with:
7394 .../configure --enable-gdbmi
7396 *** Changes in GDB-4.18:
7398 * New native configurations
7400 HP-UX 10.20 hppa*-*-hpux10.20
7401 HP-UX 11.x hppa*-*-hpux11.0*
7402 M68K GNU/Linux m68*-*-linux*
7406 Fujitsu FR30 fr30-*-elf*
7407 Intel StrongARM strongarm-*-*
7408 Mitsubishi D30V d30v-*-*
7410 * OBSOLETE configurations
7412 Gould PowerNode, NP1 np1-*-*, pn-*-*
7414 Configurations that have been declared obsolete will be commented out,
7415 but the code will be left in place. If there is no activity to revive
7416 these configurations before the next release of GDB, the sources will
7417 be permanently REMOVED.
7421 As a compatibility experiment, GDB's source files buildsym.h and
7422 buildsym.c have been converted to pure standard C, no longer
7423 containing any K&R compatibility code. We believe that all systems in
7424 use today either come with a standard C compiler, or have a GCC port
7425 available. If this is not true, please report the affected
7426 configuration to bug-gdb@gnu.org immediately. See the README file for
7427 information about getting a standard C compiler if you don't have one
7432 GDB now uses readline 2.2.
7434 * set extension-language
7436 You can now control the mapping between filename extensions and source
7437 languages by using the `set extension-language' command. For instance,
7438 you can ask GDB to treat .c files as C++ by saying
7439 set extension-language .c c++
7440 The command `info extensions' lists all of the recognized extensions
7441 and their associated languages.
7443 * Setting processor type for PowerPC and RS/6000
7445 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7446 you can use the `set processor' command to specify what variant of the
7447 PowerPC family you are debugging. The command
7451 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7452 following PowerPC and RS6000 variants:
7454 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7455 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7457 403GC IBM PowerPC 403GC
7458 505 Motorola PowerPC 505
7459 860 Motorola PowerPC 860 or 850
7460 601 Motorola PowerPC 601
7461 602 Motorola PowerPC 602
7462 603 Motorola/IBM PowerPC 603 or 603e
7463 604 Motorola PowerPC 604 or 604e
7464 750 Motorola/IBM PowerPC 750 or 750
7466 At the moment, this command just tells GDB what to name the
7467 special-purpose processor registers. Since almost all the affected
7468 registers are inaccessible to user-level programs, this command is
7469 only useful for remote debugging in its present form.
7473 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7474 more extensive support for HP-UX. Added features include shared
7475 library support, kernel threads and hardware watchpoints for 11.00,
7476 support for HP's ANSI C and C++ compilers, and a compatibility mode
7477 for xdb and dbx commands.
7481 HP's donation includes the new concept of catchpoints, which is a
7482 generalization of the old catch command. On HP-UX, it is now possible
7483 to catch exec, fork, and vfork, as well as library loading.
7485 This means that the existing catch command has changed; its first
7486 argument now specifies the type of catch to be set up. See the
7487 output of "help catch" for a list of catchpoint types.
7489 * Debugging across forks
7491 On HP-UX, you can choose which process to debug when a fork() happens
7496 HP has donated a curses-based terminal user interface (TUI). To get
7497 it, build with --enable-tui. Although this can be enabled for any
7498 configuration, at present it only works for native HP debugging.
7500 * GDB remote protocol additions
7502 A new protocol packet 'X' that writes binary data is now available.
7503 Default behavior is to try 'X', then drop back to 'M' if the stub
7504 fails to respond. The settable variable `remotebinarydownload'
7505 allows explicit control over the use of 'X'.
7507 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7508 full 64-bit address. The command
7510 set remoteaddresssize 32
7512 can be used to revert to the old behaviour. For existing remote stubs
7513 the change should not be noticed, as the additional address information
7516 In order to assist in debugging stubs, you may use the maintenance
7517 command `packet' to send any text string to the stub. For instance,
7519 maint packet heythere
7521 sends the packet "$heythere#<checksum>". Note that it is very easy to
7522 disrupt a debugging session by sending the wrong packet at the wrong
7525 The compare-sections command allows you to compare section data on the
7526 target to what is in the executable file without uploading or
7527 downloading, by comparing CRC checksums.
7529 * Tracing can collect general expressions
7531 You may now collect general expressions at tracepoints. This requires
7532 further additions to the target-side stub; see tracepoint.c and
7533 doc/agentexpr.texi for further details.
7535 * mask-address variable for Mips
7537 For Mips targets, you may control the zeroing of the upper 32 bits of
7538 a 64-bit address by entering `set mask-address on'. This is mainly
7539 of interest to users of embedded R4xxx and R5xxx processors.
7541 * Higher serial baud rates
7543 GDB's serial code now allows you to specify baud rates 57600, 115200,
7544 230400, and 460800 baud. (Note that your host system may not be able
7545 to achieve all of these rates.)
7549 The i960 configuration now includes an initial implementation of a
7550 builtin simulator, contributed by Jim Wilson.
7553 *** Changes in GDB-4.17:
7555 * New native configurations
7557 Alpha GNU/Linux alpha*-*-linux*
7558 Unixware 2.x i[3456]86-unixware2*
7559 Irix 6.x mips*-sgi-irix6*
7560 PowerPC GNU/Linux powerpc-*-linux*
7561 PowerPC Solaris powerpcle-*-solaris*
7562 Sparc GNU/Linux sparc-*-linux*
7563 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7567 Argonaut Risc Chip (ARC) arc-*-*
7568 Hitachi H8/300S h8300*-*-*
7569 Matsushita MN10200 w/simulator mn10200-*-*
7570 Matsushita MN10300 w/simulator mn10300-*-*
7571 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7572 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7573 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7574 Mitsubishi D10V w/simulator d10v-*-*
7575 Mitsubishi M32R/D w/simulator m32r-*-elf*
7576 Tsqware Sparclet sparclet-*-*
7577 NEC V850 w/simulator v850-*-*
7579 * New debugging protocols
7581 ARM with RDI protocol arm*-*-*
7582 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7583 DDB and LSI variants of PMON protocol mips*-*-*
7584 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7585 PowerPC with SDS protocol powerpc{,le}-*-eabi
7586 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7590 All configurations can now understand and use the DWARF 2 debugging
7591 format. The choice is automatic, if the symbol file contains DWARF 2
7596 GDB now includes basic Java language support. This support is
7597 only useful with Java compilers that produce native machine code.
7599 * solib-absolute-prefix and solib-search-path
7601 For SunOS and SVR4 shared libraries, you may now set the prefix for
7602 loading absolute shared library symbol files, and the search path for
7603 locating non-absolute shared library symbol files.
7605 * Live range splitting
7607 GDB can now effectively debug code for which GCC has performed live
7608 range splitting as part of its optimization. See gdb/doc/LRS for
7609 more details on the expected format of the stabs information.
7613 GDB's support for the GNU Hurd, including thread debugging, has been
7614 updated to work with current versions of the Hurd.
7618 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7619 instruction set. ARM GDB automatically detects when Thumb
7620 instructions are in use, and adjusts disassembly and backtracing
7625 GDB's MIPS target configurations now handle the MIP16 16-bit
7630 GDB now includes support for overlays; if an executable has been
7631 linked such that multiple sections are based at the same address, GDB
7632 will decide which section to use for symbolic info. You can choose to
7633 control the decision manually, using overlay commands, or implement
7634 additional target-side support and use "overlay load-target" to bring
7635 in the overlay mapping. Do "help overlay" for more detail.
7639 The command "info symbol <address>" displays information about
7640 the symbol at the specified address.
7644 The standard remote protocol now includes an extension that allows
7645 asynchronous collection and display of trace data. This requires
7646 extensive support in the target-side debugging stub. Tracing mode
7647 includes a new interaction mode in GDB and new commands: see the
7648 file tracepoint.c for more details.
7652 Configurations for embedded MIPS now include a simulator contributed
7653 by Cygnus Solutions. The simulator supports the instruction sets
7654 of most MIPS variants.
7658 Sparc configurations may now include the ERC32 simulator contributed
7659 by the European Space Agency. The simulator is not built into
7660 Sparc targets by default; configure with --enable-sim to include it.
7664 For target configurations that may include multiple variants of a
7665 basic architecture (such as MIPS and SH), you may now set the
7666 architecture explicitly. "set arch" sets, "info arch" lists
7667 the possible architectures.
7669 *** Changes in GDB-4.16:
7671 * New native configurations
7673 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7674 M68K NetBSD m68k-*-netbsd*
7675 PowerPC AIX 4.x powerpc-*-aix*
7676 PowerPC MacOS powerpc-*-macos*
7677 PowerPC Windows NT powerpcle-*-cygwin32
7678 RS/6000 AIX 4.x rs6000-*-aix4*
7682 ARM with RDP protocol arm-*-*
7683 I960 with MON960 i960-*-coff
7684 MIPS VxWorks mips*-*-vxworks*
7685 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7686 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7688 Matra Sparclet sparclet-*-*
7692 The powerpc-eabi configuration now includes the PSIM simulator,
7693 contributed by Andrew Cagney, with assistance from Mike Meissner.
7694 PSIM is a very elaborate model of the PowerPC, including not only
7695 basic instruction set execution, but also details of execution unit
7696 performance and I/O hardware. See sim/ppc/README for more details.
7700 GDB now works with Solaris 2.5.
7702 * Windows 95/NT native
7704 GDB will now work as a native debugger on Windows 95 and Windows NT.
7705 To build it from source, you must use the "gnu-win32" environment,
7706 which uses a DLL to emulate enough of Unix to run the GNU tools.
7707 Further information, binaries, and sources are available at
7708 ftp.cygnus.com, under pub/gnu-win32.
7710 * dont-repeat command
7712 If a user-defined command includes the command `dont-repeat', then the
7713 command will not be repeated if the user just types return. This is
7714 useful if the command is time-consuming to run, so that accidental
7715 extra keystrokes don't run the same command many times.
7717 * Send break instead of ^C
7719 The standard remote protocol now includes an option to send a break
7720 rather than a ^C to the target in order to interrupt it. By default,
7721 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7723 * Remote protocol timeout
7725 The standard remote protocol includes a new variable `remotetimeout'
7726 that allows you to set the number of seconds before GDB gives up trying
7727 to read from the target. The default value is 2.
7729 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7731 By default GDB will automatically keep track of objects as they are
7732 loaded and unloaded by the dynamic linker. By using the command `set
7733 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7734 when shared library events occur, thus allowing you to set breakpoints
7735 in shared libraries which are explicitly loaded by the inferior.
7737 Note this feature does not work on hpux8. On hpux9 you must link
7738 /usr/lib/end.o into your program. This feature should work
7739 automatically on hpux10.
7741 * Irix 5.x hardware watchpoint support
7743 Irix 5 configurations now support the use of hardware watchpoints.
7745 * Mips protocol "SYN garbage limit"
7747 When debugging a Mips target using the `target mips' protocol, you
7748 may set the number of characters that GDB will ignore by setting
7749 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7750 every character. The default value is 1050.
7752 * Recording and replaying remote debug sessions
7754 If you set `remotelogfile' to the name of a file, gdb will write to it
7755 a recording of a remote debug session. This recording may then be
7756 replayed back to gdb using "gdbreplay". See gdbserver/README for
7757 details. This is useful when you have a problem with GDB while doing
7758 remote debugging; you can make a recording of the session and send it
7759 to someone else, who can then recreate the problem.
7761 * Speedups for remote debugging
7763 GDB includes speedups for downloading and stepping MIPS systems using
7764 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7765 and more efficient S-record downloading.
7767 * Memory use reductions and statistics collection
7769 GDB now uses less memory and reports statistics about memory usage.
7770 Try the `maint print statistics' command, for example.
7772 *** Changes in GDB-4.15:
7774 * Psymtabs for XCOFF
7776 The symbol reader for AIX GDB now uses partial symbol tables. This
7777 can greatly improve startup time, especially for large executables.
7779 * Remote targets use caching
7781 Remote targets now use a data cache to speed up communication with the
7782 remote side. The data cache could lead to incorrect results because
7783 it doesn't know about volatile variables, thus making it impossible to
7784 debug targets which use memory mapped I/O devices. `set remotecache
7785 off' turns the data cache off.
7787 * Remote targets may have threads
7789 The standard remote protocol now includes support for multiple threads
7790 in the target system, using new protocol commands 'H' and 'T'. See
7791 gdb/remote.c for details.
7795 If GDB is configured with `--enable-netrom', then it will include
7796 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7797 acts as though it is a bank of ROM on the target board, but you can
7798 write into it over the network. GDB's support consists only of
7799 support for fast loading into the emulated ROM; to debug, you must use
7800 another protocol, such as standard remote protocol. The usual
7801 sequence is something like
7803 target nrom <netrom-hostname>
7805 target remote <netrom-hostname>:1235
7809 GDB now includes support for the Apple Macintosh, as a host only. It
7810 may be run as either an MPW tool or as a standalone application, and
7811 it can debug through the serial port. All the usual GDB commands are
7812 available, but to the target command, you must supply "serial" as the
7813 device type instead of "/dev/ttyXX". See mpw-README in the main
7814 directory for more information on how to build. The MPW configuration
7815 scripts */mpw-config.in support only a few targets, and only the
7816 mips-idt-ecoff target has been tested.
7820 GDB configuration now uses autoconf. This is not user-visible,
7821 but does simplify configuration and building.
7825 GDB now supports hpux10.
7827 *** Changes in GDB-4.14:
7829 * New native configurations
7831 x86 FreeBSD i[345]86-*-freebsd
7832 x86 NetBSD i[345]86-*-netbsd
7833 NS32k NetBSD ns32k-*-netbsd
7834 Sparc NetBSD sparc-*-netbsd
7838 A29K VxWorks a29k-*-vxworks
7839 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7840 CPU32 EST-300 emulator m68*-*-est*
7841 PowerPC ELF powerpc-*-elf
7844 * Alpha OSF/1 support for procfs
7846 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7847 possible to attach to running processes. As the mounting of the /proc
7848 filesystem is optional on the Alpha, GDB automatically determines
7849 the availability of /proc during startup. This can lead to problems
7850 if /proc is unmounted after GDB has been started.
7852 * Arguments to user-defined commands
7854 User commands may accept up to 10 arguments separated by whitespace.
7855 Arguments are accessed within the user command via $arg0..$arg9. A
7858 print $arg0 + $arg1 + $arg2
7860 To execute the command use:
7863 Defines the command "adder" which prints the sum of its three arguments.
7864 Note the arguments are text substitutions, so they may reference variables,
7865 use complex expressions, or even perform inferior function calls.
7867 * New `if' and `while' commands
7869 This makes it possible to write more sophisticated user-defined
7870 commands. Both commands take a single argument, which is the
7871 expression to evaluate, and must be followed by the commands to
7872 execute, one per line, if the expression is nonzero, the list being
7873 terminated by the word `end'. The `if' command list may include an
7874 `else' word, which causes the following commands to be executed only
7875 if the expression is zero.
7877 * Fortran source language mode
7879 GDB now includes partial support for Fortran 77. It will recognize
7880 Fortran programs and can evaluate a subset of Fortran expressions, but
7881 variables and functions may not be handled correctly. GDB will work
7882 with G77, but does not yet know much about symbols emitted by other
7885 * Better HPUX support
7887 Most debugging facilities now work on dynamic executables for HPPAs
7888 running hpux9 or later. You can attach to running dynamically linked
7889 processes, but by default the dynamic libraries will be read-only, so
7890 for instance you won't be able to put breakpoints in them. To change
7891 that behavior do the following before running the program:
7897 This will cause the libraries to be mapped private and read-write.
7898 To revert to the normal behavior, do this:
7904 You cannot set breakpoints or examine data in the library until after
7905 the library is loaded if the function/data symbols do not have
7908 GDB can now also read debug symbols produced by the HP C compiler on
7909 HPPAs (sorry, no C++, Fortran or 68k support).
7911 * Target byte order now dynamically selectable
7913 You can choose which byte order to use with a target system, via the
7914 commands "set endian big" and "set endian little", and you can see the
7915 current setting by using "show endian". You can also give the command
7916 "set endian auto", in which case GDB will use the byte order
7917 associated with the executable. Currently, only embedded MIPS
7918 configurations support dynamic selection of target byte order.
7920 * New DOS host serial code
7922 This version uses DPMI interrupts to handle buffered I/O, so you
7923 no longer need to run asynctsr when debugging boards connected to
7926 *** Changes in GDB-4.13:
7928 * New "complete" command
7930 This lists all the possible completions for the rest of the line, if it
7931 were to be given as a command itself. This is intended for use by emacs.
7933 * Trailing space optional in prompt
7935 "set prompt" no longer adds a space for you after the prompt you set. This
7936 allows you to set a prompt which ends in a space or one that does not.
7938 * Breakpoint hit counts
7940 "info break" now displays a count of the number of times the breakpoint
7941 has been hit. This is especially useful in conjunction with "ignore"; you
7942 can ignore a large number of breakpoint hits, look at the breakpoint info
7943 to see how many times the breakpoint was hit, then run again, ignoring one
7944 less than that number, and this will get you quickly to the last hit of
7947 * Ability to stop printing at NULL character
7949 "set print null-stop" will cause GDB to stop printing the characters of
7950 an array when the first NULL is encountered. This is useful when large
7951 arrays actually contain only short strings.
7953 * Shared library breakpoints
7955 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
7956 breakpoints in shared libraries before the executable is run.
7958 * Hardware watchpoints
7960 There is a new hardware breakpoint for the watch command for sparclite
7961 targets. See gdb/sparclite/hw_breakpoint.note.
7963 Hardware watchpoints are also now supported under GNU/Linux.
7967 Annotations have been added. These are for use with graphical interfaces,
7968 and are still experimental. Currently only gdba.el uses these.
7970 * Improved Irix 5 support
7972 GDB now works properly with Irix 5.2.
7974 * Improved HPPA support
7976 GDB now works properly with the latest GCC and GAS.
7978 * New native configurations
7980 Sequent PTX4 i[34]86-sequent-ptx4
7981 HPPA running OSF/1 hppa*-*-osf*
7982 Atari TT running SVR4 m68*-*-sysv4*
7983 RS/6000 LynxOS rs6000-*-lynxos*
7987 OS/9000 i[34]86-*-os9k
7988 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
7991 * Hitachi SH7000 and E7000-PC ICE support
7993 There is now support for communicating with the Hitachi E7000-PC ICE.
7994 This is available automatically when GDB is configured for the SH.
7998 As usual, a variety of small fixes and improvements, both generic
7999 and configuration-specific. See the ChangeLog for more detail.
8001 *** Changes in GDB-4.12:
8003 * Irix 5 is now supported
8007 GDB-4.12 on the HPPA has a number of changes which make it unable
8008 to debug the output from the currently released versions of GCC and
8009 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8010 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8011 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8014 *** Changes in GDB-4.11:
8016 * User visible changes:
8020 The "set remotedebug" option is now consistent between the mips remote
8021 target, remote targets using the gdb-specific protocol, UDI (AMD's
8022 debug protocol for the 29k) and the 88k bug monitor. It is now an
8023 integer specifying a debug level (normally 0 or 1, but 2 means more
8024 debugging info for the mips target).
8026 * DEC Alpha native support
8028 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8029 debug info, but GDB works fairly well with the DEC compiler and should
8030 work with a future GCC release. See the README file for a few
8031 Alpha-specific notes.
8033 * Preliminary thread implementation
8035 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8037 * LynxOS native and target support for 386
8039 This release has been hosted on LynxOS 2.2, and also can be configured
8040 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8043 * Improvements in C++ mangling/demangling.
8045 This release has much better g++ debugging, specifically in name
8046 mangling/demangling, virtual function calls, print virtual table,
8047 call methods, ...etc.
8049 *** Changes in GDB-4.10:
8051 * User visible changes:
8053 Remote debugging using the GDB-specific (`target remote') protocol now
8054 supports the `load' command. This is only useful if you have some
8055 other way of getting the stub to the target system, and you can put it
8056 somewhere in memory where it won't get clobbered by the download.
8058 Filename completion now works.
8060 When run under emacs mode, the "info line" command now causes the
8061 arrow to point to the line specified. Also, "info line" prints
8062 addresses in symbolic form (as well as hex).
8064 All vxworks based targets now support a user settable option, called
8065 vxworks-timeout. This option represents the number of seconds gdb
8066 should wait for responses to rpc's. You might want to use this if
8067 your vxworks target is, perhaps, a slow software simulator or happens
8068 to be on the far side of a thin network line.
8072 This release contains support for using a DEC alpha as a GDB host for
8073 cross debugging. Native alpha debugging is not supported yet.
8076 *** Changes in GDB-4.9:
8080 This is the first GDB release which is accompanied by a matching testsuite.
8081 The testsuite requires installation of dejagnu, which should be available
8082 via ftp from most sites that carry GNU software.
8086 'Cfront' style demangling has had its name changed to 'ARM' style, to
8087 emphasize that it was written from the specifications in the C++ Annotated
8088 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8089 disclaimers, it still generated too much confusion with users attempting to
8090 use gdb with AT&T cfront.
8094 GDB now uses a standard remote interface to a simulator library.
8095 So far, the library contains simulators for the Zilog Z8001/2, the
8096 Hitachi H8/300, H8/500 and Super-H.
8098 * New targets supported
8100 H8/300 simulator h8300-hitachi-hms or h8300hms
8101 H8/500 simulator h8500-hitachi-hms or h8500hms
8102 SH simulator sh-hitachi-hms or sh
8103 Z8000 simulator z8k-zilog-none or z8ksim
8104 IDT MIPS board over serial line mips-idt-ecoff
8106 Cross-debugging to GO32 targets is supported. It requires a custom
8107 version of the i386-stub.c module which is integrated with the
8108 GO32 memory extender.
8110 * New remote protocols
8112 MIPS remote debugging protocol.
8114 * New source languages supported
8116 This version includes preliminary support for Chill, a Pascal like language
8117 used by telecommunications companies. Chill support is also being integrated
8118 into the GNU compiler, but we don't know when it will be publically available.
8121 *** Changes in GDB-4.8:
8123 * HP Precision Architecture supported
8125 GDB now supports HP PA-RISC machines running HPUX. A preliminary
8126 version of this support was available as a set of patches from the
8127 University of Utah. GDB does not support debugging of programs
8128 compiled with the HP compiler, because HP will not document their file
8129 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
8130 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
8132 Many problems in the preliminary version have been fixed.
8134 * Faster and better demangling
8136 We have improved template demangling and fixed numerous bugs in the GNU style
8137 demangler. It can now handle type modifiers such as `static' or `const'. Wide
8138 character types (wchar_t) are now supported. Demangling of each symbol is now
8139 only done once, and is cached when the symbol table for a file is read in.
8140 This results in a small increase in memory usage for C programs, a moderate
8141 increase in memory usage for C++ programs, and a fantastic speedup in
8144 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
8145 from the specifications in the Annotated Reference Manual, which AT&T's
8146 compiler does not actually implement.
8148 * G++ multiple inheritance compiler problem
8150 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
8151 inheritance lattices was reworked to properly discover ambiguities. We
8152 recently found an example which causes this new algorithm to fail in a
8153 very subtle way, producing bad debug information for those classes.
8154 The file 'gcc.patch' (in this directory) can be applied to gcc to
8155 circumvent the problem. A future GCC release will contain a complete
8158 The previous G++ debug info problem (mentioned below for the gdb-4.7
8159 release) is fixed in gcc version 2.3.2.
8161 * Improved configure script
8163 The `configure' script will now attempt to guess your system type if
8164 you don't supply a host system type. The old scheme of supplying a
8165 host system triplet is preferable over using this. All the magic is
8166 done in the new `config.guess' script. Examine it for details.
8168 We have also brought our configure script much more in line with the FSF's
8169 version. It now supports the --with-xxx options. In particular,
8170 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
8171 The resulting GDB will not be able to read arbitrary object file formats --
8172 only the format ``expected'' to be used on the configured target system.
8173 We hope to make this the default in a future release.
8175 * Documentation improvements
8177 There's new internal documentation on how to modify GDB, and how to
8178 produce clean changes to the code. We implore people to read it
8179 before submitting changes.
8181 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
8182 M4 macros. The new texinfo.tex is provided in this release. Pre-built
8183 `info' files are also provided. To build `info' files from scratch,
8184 you will need the latest `makeinfo' release, which will be available in
8185 a future texinfo-X.Y release.
8187 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
8188 We're not sure exactly which versions have this problem, but it has
8189 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
8190 or better. If that isn't possible, there is a patch in
8191 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
8192 around this problem.
8196 GDB now supports array constants that can be used in expressions typed in by
8197 the user. The syntax is `{element, element, ...}'. Ie: you can now type
8198 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
8201 The new directory `gdb/sparclite' contains a program that demonstrates
8202 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
8204 * New native hosts supported
8206 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
8207 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
8209 * New targets supported
8211 AMD 29k family via UDI a29k-amd-udi or udi29k
8213 * New file formats supported
8215 BFD now supports reading HP/PA-RISC executables (SOM file format?),
8216 HPUX core files, and SCO 3.2v2 core files.
8220 Attaching to processes now works again; thanks for the many bug reports.
8222 We have also stomped on a bunch of core dumps caused by
8223 printf_filtered("%s") problems.
8225 We eliminated a copyright problem on the rpc and ptrace header files
8226 for VxWorks, which was discovered at the last minute during the 4.7
8227 release. You should now be able to build a VxWorks GDB.
8229 You can now interrupt gdb while an attached process is running. This
8230 will cause the attached process to stop, and give control back to GDB.
8232 We fixed problems caused by using too many file descriptors
8233 for reading symbols from object files and libraries. This was
8234 especially a problem for programs that used many (~100) shared
8237 The `step' command now only enters a subroutine if there is line number
8238 information for the subroutine. Otherwise it acts like the `next'
8239 command. Previously, `step' would enter subroutines if there was
8240 any debugging information about the routine. This avoids problems
8241 when using `cc -g1' on MIPS machines.
8243 * Internal improvements
8245 GDB's internal interfaces have been improved to make it easier to support
8246 debugging of multiple languages in the future.
8248 GDB now uses a common structure for symbol information internally.
8249 Minimal symbols (derived from linkage symbols in object files), partial
8250 symbols (from a quick scan of debug information), and full symbols
8251 contain a common subset of information, making it easier to write
8252 shared code that handles any of them.
8254 * New command line options
8256 We now accept --silent as an alias for --quiet.
8260 The memory-mapped-malloc library is now licensed under the GNU Library
8261 General Public License.
8263 *** Changes in GDB-4.7:
8265 * Host/native/target split
8267 GDB has had some major internal surgery to untangle the support for
8268 hosts and remote targets. Now, when you configure GDB for a remote
8269 target, it will no longer load in all of the support for debugging
8270 local programs on the host. When fully completed and tested, this will
8271 ensure that arbitrary host/target combinations are possible.
8273 The primary conceptual shift is to separate the non-portable code in
8274 GDB into three categories. Host specific code is required any time GDB
8275 is compiled on that host, regardless of the target. Target specific
8276 code relates to the peculiarities of the target, but can be compiled on
8277 any host. Native specific code is everything else: it can only be
8278 built when the host and target are the same system. Child process
8279 handling and core file support are two common `native' examples.
8281 GDB's use of /proc for controlling Unix child processes is now cleaner.
8282 It has been split out into a single module under the `target_ops' vector,
8283 plus two native-dependent functions for each system that uses /proc.
8285 * New hosts supported
8287 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8288 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8289 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8291 * New targets supported
8293 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8294 68030 and CPU32 m68030-*-*, m68332-*-*
8296 * New native hosts supported
8298 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8299 (386bsd is not well tested yet)
8300 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8302 * New file formats supported
8304 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8305 supports reading of `a.out.adobe' object files, which are an a.out
8306 format extended with minimal information about multiple sections.
8310 `show copying' is the same as the old `info copying'.
8311 `show warranty' is the same as `info warrantee'.
8312 These were renamed for consistency. The old commands continue to work.
8314 `info handle' is a new alias for `info signals'.
8316 You can now define pre-command hooks, which attach arbitrary command
8317 scripts to any command. The commands in the hook will be executed
8318 prior to the user's command. You can also create a hook which will be
8319 executed whenever the program stops. See gdb.texinfo.
8323 We now deal with Cfront style name mangling, and can even extract type
8324 info from mangled symbols. GDB can automatically figure out which
8325 symbol mangling style your C++ compiler uses.
8327 Calling of methods and virtual functions has been improved as well.
8331 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8332 fixed. This was due to mishandling of the extra N_SO stabs output
8335 We also finally got Ultrix 4.2 running in house, and fixed core file
8336 support, with help from a dozen people on the net.
8338 John M. Farrell discovered that the reason that single-stepping was so
8339 slow on all of the Mips based platforms (primarily SGI and DEC) was
8340 that we were trying to demangle and lookup a symbol used for internal
8341 purposes on every instruction that was being stepped through. Changing
8342 the name of that symbol so that it couldn't be mistaken for a C++
8343 mangled symbol sped things up a great deal.
8345 Rich Pixley sped up symbol lookups in general by getting much smarter
8346 about when C++ symbol mangling is necessary. This should make symbol
8347 completion (TAB on the command line) much faster. It's not as fast as
8348 we'd like, but it's significantly faster than gdb-4.6.
8352 A new user controllable variable 'call_scratch_address' can
8353 specify the location of a scratch area to be used when GDB
8354 calls a function in the target. This is necessary because the
8355 usual method of putting the scratch area on the stack does not work
8356 in systems that have separate instruction and data spaces.
8358 We integrated changes to support the 29k UDI (Universal Debugger
8359 Interface), but discovered at the last minute that we didn't have all
8360 of the appropriate copyright paperwork. We are working with AMD to
8361 resolve this, and hope to have it available soon.
8365 We have sped up the remote serial line protocol, especially for targets
8366 with lots of registers. It now supports a new `expedited status' ('T')
8367 message which can be used in place of the existing 'S' status message.
8368 This allows the remote stub to send only the registers that GDB
8369 needs to make a quick decision about single-stepping or conditional
8370 breakpoints, eliminating the need to fetch the entire register set for
8371 each instruction being stepped through.
8373 The GDB remote serial protocol now implements a write-through cache for
8374 registers, only re-reading the registers if the target has run.
8376 There is also a new remote serial stub for SPARC processors. You can
8377 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8378 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8379 processor with a serial port.
8383 Configure.in files have become much easier to read and modify. A new
8384 `table driven' format makes it more obvious what configurations are
8385 supported, and what files each one uses.
8389 There is a new opcodes library which will eventually contain all of the
8390 disassembly routines and opcode tables. At present, it only contains
8391 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8392 disassembler (binutils/objdump) to share these routines.
8394 The libiberty library is now copylefted under the GNU Library General
8395 Public License. This allows more liberal use, and was done so libg++
8396 can use it. This makes no difference to GDB, since the Library License
8397 grants all the rights from the General Public License.
8401 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8402 reference to the stabs symbol info used by the debugger. It is (as far
8403 as we know) the only published document on this fascinating topic. We
8404 encourage you to read it, compare it to the stabs information on your
8405 system, and send improvements on the document in general (to
8406 bug-gdb@prep.ai.mit.edu).
8408 And, of course, many bugs have been fixed.
8411 *** Changes in GDB-4.6:
8413 * Better support for C++ function names
8415 GDB now accepts as input the "demangled form" of C++ overloaded function
8416 names and member function names, and can do command completion on such names
8417 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8418 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8419 Make use of command completion, it is your friend.
8421 GDB also now accepts a variety of C++ mangled symbol formats. They are
8422 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8423 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8424 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8425 for the list of formats.
8427 * G++ symbol mangling problem
8429 Recent versions of gcc have a bug in how they emit debugging information for
8430 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8431 directory) can be applied to gcc to fix the problem. Alternatively, if you
8432 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8433 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8434 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8437 * New 'maintenance' command
8439 All of the commands related to hacking GDB internals have been moved out of
8440 the main command set, and now live behind the 'maintenance' command. This
8441 can also be abbreviated as 'mt'. The following changes were made:
8443 dump-me -> maintenance dump-me
8444 info all-breakpoints -> maintenance info breakpoints
8445 printmsyms -> maintenance print msyms
8446 printobjfiles -> maintenance print objfiles
8447 printpsyms -> maintenance print psymbols
8448 printsyms -> maintenance print symbols
8450 The following commands are new:
8452 maintenance demangle Call internal GDB demangler routine to
8453 demangle a C++ link name and prints the result.
8454 maintenance print type Print a type chain for a given symbol
8456 * Change to .gdbinit file processing
8458 We now read the $HOME/.gdbinit file before processing the argv arguments
8459 (e.g. reading symbol files or core files). This allows global parameters to
8460 be set, which will apply during the symbol reading. The ./.gdbinit is still
8461 read after argv processing.
8463 * New hosts supported
8465 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8467 GNU/Linux support i386-unknown-linux or linux
8469 We are also including code to support the HP/PA running BSD and HPUX. This
8470 is almost guaranteed not to work, as we didn't have time to test or build it
8471 for this release. We are including it so that the more adventurous (or
8472 masochistic) of you can play with it. We also had major problems with the
8473 fact that the compiler that we got from HP doesn't support the -g option.
8476 * New targets supported
8478 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8480 * More smarts about finding #include files
8482 GDB now remembers the compilation directory for all include files, and for
8483 all files from which C is generated (like yacc and lex sources). This
8484 greatly improves GDB's ability to find yacc/lex sources, and include files,
8485 especially if you are debugging your program from a directory different from
8486 the one that contains your sources.
8488 We also fixed a bug which caused difficulty with listing and setting
8489 breakpoints in include files which contain C code. (In the past, you had to
8490 try twice in order to list an include file that you hadn't looked at before.)
8492 * Interesting infernals change
8494 GDB now deals with arbitrary numbers of sections, where the symbols for each
8495 section must be relocated relative to that section's landing place in the
8496 target's address space. This work was needed to support ELF with embedded
8497 stabs used by Solaris-2.0.
8499 * Bug fixes (of course!)
8501 There have been loads of fixes for the following things:
8502 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8503 i960, stabs, DOS(GO32), procfs, etc...
8505 See the ChangeLog for details.
8507 *** Changes in GDB-4.5:
8509 * New machines supported (host and target)
8511 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8513 SGI Irix-4.x mips-sgi-irix4 or iris4
8515 * New malloc package
8517 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8518 Mmalloc is capable of handling multiple heaps of memory. It is also
8519 capable of saving a heap to a file, and then mapping it back in later.
8520 This can be used to greatly speedup the startup of GDB by using a
8521 pre-parsed symbol table which lives in a mmalloc managed heap. For
8522 more details, please read mmalloc/mmalloc.texi.
8526 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8527 'help info proc' for details.
8529 * MIPS ecoff symbol table format
8531 The code that reads MIPS symbol table format is now supported on all hosts.
8532 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8535 * File name changes for MS-DOS
8537 Many files in the config directories have been renamed to make it easier to
8538 support GDB on MS-DOSe systems (which have very restrictive file name
8539 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8540 environment) is close to working but has some remaining problems. Note
8541 that debugging of DOS programs is not supported, due to limitations
8542 in the ``operating system'', but it can be used to host cross-debugging.
8544 * Cross byte order fixes
8546 Many fixes have been made to support cross debugging of Sparc and MIPS
8547 targets from hosts whose byte order differs.
8549 * New -mapped and -readnow options
8551 If memory-mapped files are available on your system through the 'mmap'
8552 system call, you can use the -mapped option on the `file' or
8553 `symbol-file' commands to cause GDB to write the symbols from your
8554 program into a reusable file. If the program you are debugging is
8555 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8556 Future GDB debugging sessions will notice the presence of this file,
8557 and will quickly map in symbol information from it, rather than reading
8558 the symbol table from the executable program. Using the '-mapped'
8559 option in a GDB `file' or `symbol-file' command has the same effect as
8560 starting GDB with the '-mapped' command-line option.
8562 You can cause GDB to read the entire symbol table immediately by using
8563 the '-readnow' option with any of the commands that load symbol table
8564 information (or on the GDB command line). This makes the command
8565 slower, but makes future operations faster.
8567 The -mapped and -readnow options are typically combined in order to
8568 build a `fred.syms' file that contains complete symbol information.
8569 A simple GDB invocation to do nothing but build a `.syms' file for future
8572 gdb -batch -nx -mapped -readnow programname
8574 The `.syms' file is specific to the host machine on which GDB is run.
8575 It holds an exact image of GDB's internal symbol table. It cannot be
8576 shared across multiple host platforms.
8578 * longjmp() handling
8580 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8581 siglongjmp() without losing control. This feature has not yet been ported to
8582 all systems. It currently works on many 386 platforms, all MIPS-based
8583 platforms (SGI, DECstation, etc), and Sun3/4.
8587 Preliminary work has been put in to support the new Solaris OS from Sun. At
8588 this time, it can control and debug processes, but it is not capable of
8593 As always, many many bug fixes. The major areas were with g++, and mipsread.
8594 People using the MIPS-based platforms should experience fewer mysterious
8595 crashes and trashed symbol tables.
8597 *** Changes in GDB-4.4:
8599 * New machines supported (host and target)
8601 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8603 BSD Reno on Vax vax-dec-bsd
8604 Ultrix on Vax vax-dec-ultrix
8606 * New machines supported (target)
8608 AMD 29000 embedded, using EBMON a29k-none-none
8612 GDB continues to improve its handling of C++. `References' work better.
8613 The demangler has also been improved, and now deals with symbols mangled as
8614 per the Annotated C++ Reference Guide.
8616 GDB also now handles `stabs' symbol information embedded in MIPS
8617 `ecoff' symbol tables. Since the ecoff format was not easily
8618 extensible to handle new languages such as C++, this appeared to be a
8619 good way to put C++ debugging info into MIPS binaries. This option
8620 will be supported in the GNU C compiler, version 2, when it is
8623 * New features for SVR4
8625 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8626 shared libraries. Debugging dynamically linked programs should present
8627 only minor differences from debugging statically linked programs.
8629 The `info proc' command will print out information about any process
8630 on an SVR4 system (including the one you are debugging). At the moment,
8631 it prints the address mappings of the process.
8633 If you bring up GDB on another SVR4 system, please send mail to
8634 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8636 * Better dynamic linking support in SunOS
8638 Reading symbols from shared libraries which contain debugging symbols
8639 now works properly. However, there remain issues such as automatic
8640 skipping of `transfer vector' code during function calls, which
8641 make it harder to debug code in a shared library, than to debug the
8642 same code linked statically.
8646 GDB is now using the latest `getopt' routines from the FSF. This
8647 version accepts the -- prefix for options with long names. GDB will
8648 continue to accept the old forms (-option and +option) as well.
8649 Various single letter abbreviations for options have been explicity
8650 added to the option table so that they won't get overshadowed in the
8651 future by other options that begin with the same letter.
8655 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8656 Many assorted bugs have been handled. Many more remain to be handled.
8657 See the various ChangeLog files (primarily in gdb and bfd) for details.
8660 *** Changes in GDB-4.3:
8662 * New machines supported (host and target)
8664 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8665 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8666 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8668 * Almost SCO Unix support
8670 We had hoped to support:
8671 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8672 (except for core file support), but we discovered very late in the release
8673 that it has problems with process groups that render gdb unusable. Sorry
8674 about that. I encourage people to fix it and post the fixes.
8676 * Preliminary ELF and DWARF support
8678 GDB can read ELF object files on System V Release 4, and can handle
8679 debugging records for C, in DWARF format, in ELF files. This support
8680 is preliminary. If you bring up GDB on another SVR4 system, please
8681 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8686 GDB now uses the latest `readline' library. One user-visible change
8687 is that two tabs will list possible command completions, which previously
8688 required typing M-? (meta-question mark, or ESC ?).
8692 The `stepi' bug that many of you noticed has been squashed.
8693 Many bugs in C++ have been handled. Many more remain to be handled.
8694 See the various ChangeLog files (primarily in gdb and bfd) for details.
8696 * State of the MIPS world (in case you wondered):
8698 GDB can understand the symbol tables emitted by the compilers
8699 supplied by most vendors of MIPS-based machines, including DEC. These
8700 symbol tables are in a format that essentially nobody else uses.
8702 Some versions of gcc come with an assembler post-processor called
8703 mips-tfile. This program is required if you want to do source-level
8704 debugging of gcc-compiled programs. I believe FSF does not ship
8705 mips-tfile with gcc version 1, but it will eventually come with gcc
8708 Debugging of g++ output remains a problem. g++ version 1.xx does not
8709 really support it at all. (If you're lucky, you should be able to get
8710 line numbers and stack traces to work, but no parameters or local
8711 variables.) With some work it should be possible to improve the
8714 When gcc version 2 is released, you will have somewhat better luck.
8715 However, even then you will get confusing results for inheritance and
8718 We will eventually provide full debugging of g++ output on
8719 DECstations. This will probably involve some kind of stabs-in-ecoff
8720 encapulation, but the details have not been worked out yet.
8723 *** Changes in GDB-4.2:
8725 * Improved configuration
8727 Only one copy of `configure' exists now, and it is not self-modifying.
8728 Porting BFD is simpler.
8732 The `step' and `next' commands now only stop at the first instruction
8733 of a source line. This prevents the multiple stops that used to occur
8734 in switch statements, for-loops, etc. `Step' continues to stop if a
8735 function that has debugging information is called within the line.
8739 Lots of small bugs fixed. More remain.
8741 * New host supported (not target)
8743 Intel 386 PC clone running Mach i386-none-mach
8746 *** Changes in GDB-4.1:
8748 * Multiple source language support
8750 GDB now has internal scaffolding to handle several source languages.
8751 It determines the type of each source file from its filename extension,
8752 and will switch expression parsing and number formatting to match the
8753 language of the function in the currently selected stack frame.
8754 You can also specifically set the language to be used, with
8755 `set language c' or `set language modula-2'.
8759 GDB now has preliminary support for the GNU Modula-2 compiler,
8760 currently under development at the State University of New York at
8761 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8762 continue through the fall of 1991 and into 1992.
8764 Other Modula-2 compilers are currently not supported, and attempting to
8765 debug programs compiled with them will likely result in an error as the
8766 symbol table is read. Feel free to work on it, though!
8768 There are hooks in GDB for strict type checking and range checking,
8769 in the `Modula-2 philosophy', but they do not currently work.
8773 GDB can now write to executable and core files (e.g. patch
8774 a variable's value). You must turn this switch on, specify
8775 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8776 by assigning a new value to a variable. Modifications take
8779 * Automatic SunOS shared library reading
8781 When you run your program, GDB automatically determines where its
8782 shared libraries (if any) have been loaded, and reads their symbols.
8783 The `share' command is no longer needed. This also works when
8784 examining core files.
8788 You can specify the number of lines that the `list' command shows.
8791 * New machines supported (host and target)
8793 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8794 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8795 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8797 * New hosts supported (not targets)
8799 IBM RT/PC: romp-ibm-aix or rtpc
8801 * New targets supported (not hosts)
8803 AMD 29000 embedded with COFF a29k-none-coff
8804 AMD 29000 embedded with a.out a29k-none-aout
8805 Ultracomputer remote kernel debug a29k-nyu-kern
8807 * New remote interfaces
8813 *** Changes in GDB-4.0:
8817 Wide output is wrapped at good places to make the output more readable.
8819 Gdb now supports cross-debugging from a host machine of one type to a
8820 target machine of another type. Communication with the target system
8821 is over serial lines. The ``target'' command handles connecting to the
8822 remote system; the ``load'' command will download a program into the
8823 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8824 also supports debugging of realtime processes running under VxWorks,
8825 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8826 stub on the target system.
8828 New CPUs supported include the AMD 29000 and Intel 960.
8830 GDB now reads object files and symbol tables via a ``binary file''
8831 library, which allows a single copy of GDB to debug programs of multiple
8832 object file types such as a.out and coff.
8834 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8835 refcard.dvi and refcard.ps are available to format it).
8838 * Control-Variable user interface simplified
8840 All variables that control the operation of the debugger can be set
8841 by the ``set'' command, and displayed by the ``show'' command.
8843 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8844 ``Show prompt'' produces the response:
8845 Gdb's prompt is new-gdb=>.
8847 What follows are the NEW set commands. The command ``help set'' will
8848 print a complete list of old and new set commands. ``help set FOO''
8849 will give a longer description of the variable FOO. ``show'' will show
8850 all of the variable descriptions and their current settings.
8852 confirm on/off: Enables warning questions for operations that are
8853 hard to recover from, e.g. rerunning the program while
8854 it is already running. Default is ON.
8856 editing on/off: Enables EMACS style command line editing
8857 of input. Previous lines can be recalled with
8858 control-P, the current line can be edited with control-B,
8859 you can search for commands with control-R, etc.
8862 history filename NAME: NAME is where the gdb command history
8863 will be stored. The default is .gdb_history,
8864 or the value of the environment variable
8867 history size N: The size, in commands, of the command history. The
8868 default is 256, or the value of the environment variable
8871 history save on/off: If this value is set to ON, the history file will
8872 be saved after exiting gdb. If set to OFF, the
8873 file will not be saved. The default is OFF.
8875 history expansion on/off: If this value is set to ON, then csh-like
8876 history expansion will be performed on
8877 command line input. The default is OFF.
8879 radix N: Sets the default radix for input and output. It can be set
8880 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8881 in the current radix, so "set radix 10" is always a no-op.
8883 height N: This integer value is the number of lines on a page. Default
8884 is 24, the current `stty rows'' setting, or the ``li#''
8885 setting from the termcap entry matching the environment
8888 width N: This integer value is the number of characters on a line.
8889 Default is 80, the current `stty cols'' setting, or the ``co#''
8890 setting from the termcap entry matching the environment
8893 Note: ``set screensize'' is obsolete. Use ``set height'' and
8894 ``set width'' instead.
8896 print address on/off: Print memory addresses in various command displays,
8897 such as stack traces and structure values. Gdb looks
8898 more ``symbolic'' if you turn this off; it looks more
8899 ``machine level'' with it on. Default is ON.
8901 print array on/off: Prettyprint arrays. New convenient format! Default
8904 print demangle on/off: Print C++ symbols in "source" form if on,
8907 print asm-demangle on/off: Same, for assembler level printouts
8910 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
8913 * Support for Epoch Environment.
8915 The epoch environment is a version of Emacs v18 with windowing. One
8916 new command, ``inspect'', is identical to ``print'', except that if you
8917 are running in the epoch environment, the value is printed in its own
8921 * Support for Shared Libraries
8923 GDB can now debug programs and core files that use SunOS shared libraries.
8924 Symbols from a shared library cannot be referenced
8925 before the shared library has been linked with the program (this
8926 happens after you type ``run'' and before the function main() is entered).
8927 At any time after this linking (including when examining core files
8928 from dynamically linked programs), gdb reads the symbols from each
8929 shared library when you type the ``sharedlibrary'' command.
8930 It can be abbreviated ``share''.
8932 sharedlibrary REGEXP: Load shared object library symbols for files
8933 matching a unix regular expression. No argument
8934 indicates to load symbols for all shared libraries.
8936 info sharedlibrary: Status of loaded shared libraries.
8941 A watchpoint stops execution of a program whenever the value of an
8942 expression changes. Checking for this slows down execution
8943 tremendously whenever you are in the scope of the expression, but is
8944 quite useful for catching tough ``bit-spreader'' or pointer misuse
8945 problems. Some machines such as the 386 have hardware for doing this
8946 more quickly, and future versions of gdb will use this hardware.
8948 watch EXP: Set a watchpoint (breakpoint) for an expression.
8950 info watchpoints: Information about your watchpoints.
8952 delete N: Deletes watchpoint number N (same as breakpoints).
8953 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
8954 enable N: Re-enables watchpoint number N (same as breakpoints).
8957 * C++ multiple inheritance
8959 When used with a GCC version 2 compiler, GDB supports multiple inheritance
8962 * C++ exception handling
8964 Gdb now supports limited C++ exception handling. Besides the existing
8965 ability to breakpoint on an exception handler, gdb can breakpoint on
8966 the raising of an exception (before the stack is peeled back to the
8969 catch FOO: If there is a FOO exception handler in the dynamic scope,
8970 set a breakpoint to catch exceptions which may be raised there.
8971 Multiple exceptions (``catch foo bar baz'') may be caught.
8973 info catch: Lists all exceptions which may be caught in the
8974 current stack frame.
8977 * Minor command changes
8979 The command ``call func (arg, arg, ...)'' now acts like the print
8980 command, except it does not print or save a value if the function's result
8981 is void. This is similar to dbx usage.
8983 The ``up'' and ``down'' commands now always print the frame they end up
8984 at; ``up-silently'' and `down-silently'' can be used in scripts to change
8985 frames without printing.
8987 * New directory command
8989 'dir' now adds directories to the FRONT of the source search path.
8990 The path starts off empty. Source files that contain debug information
8991 about the directory in which they were compiled can be found even
8992 with an empty path; Sun CC and GCC include this information. If GDB can't
8993 find your source file in the current directory, type "dir .".
8995 * Configuring GDB for compilation
8997 For normal use, type ``./configure host''. See README or gdb.texinfo
9000 GDB now handles cross debugging. If you are remotely debugging between
9001 two different machines, type ``./configure host -target=targ''.
9002 Host is the machine where GDB will run; targ is the machine
9003 where the program that you are debugging will run.