1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 13
6 * The AArch64 'org.gnu.gdb.aarch64.pauth' Pointer Authentication feature string
7 has been deprecated in favor of the 'org.gnu.gdb.aarch64.pauth_v2' feature
10 * GDB now has some support for integer types larger than 64 bits.
12 * Removed targets and native configurations
14 GDB no longer supports AIX 4.x, AIX 5.x and AIX 6.x. The minimum supported
15 AIX version is now AIX 7.1.
17 * Multi-target feature configuration
19 GDB now supports the individual configuration of remote targets' feature
20 sets. Based on the current selection of a target, the commands 'set remote
21 <name>-packet (on|off|auto)' and 'show remote <name>-packet' can be used to
22 configure a target's feature packet and to display its configuration,
25 The individual packet sizes can be configured and shown using the commands
26 ** 'set remote memory-read-packet-size (number of bytes|fixed|limit)'
27 ** 'set remote memory-write-packet-size (number of bytes|fixed|limit)'
28 ** 'show remote memory-read-packet-size'
29 ** 'show remote memory-write-packet-size'.
31 The configuration of the packet itself, as well as the size of a memory-read
32 or memory-write packet applies to the currently selected target (if
33 available). If no target is selected, it applies to future remote
34 connections. Similarly, the show commands print the configuration of the
35 currently selected target. If no remote target is selected, the default
36 configuration for future connections is shown.
38 * MI version 1 has been removed.
40 * GDB has initial built-in support for the Debugger Adapter Protocol.
41 This support requires that GDB be built with Python scripting
44 * For the break command, multiple uses of the 'thread' or 'task'
45 keywords will now give an error instead of just using the thread or
46 task id from the last instance of the keyword. E.g.:
47 break foo thread 1 thread 2
48 will now give an error rather than using 'thread 2'.
50 * For the watch command, multiple uses of the 'task' keyword will now
51 give an error instead of just using the task id from the last
52 instance of the keyword. E.g.:
53 watch my_var task 1 task 2
54 will now give an error rather than using 'task 2'. The 'thread'
55 keyword already gave an error when used multiple times with the
56 watch command, this remains unchanged.
58 * The 'set print elements' setting now helps when printing large arrays.
59 If an array would otherwise exceed max-value-size, but 'print elements'
60 is set such that the size of elements to print is less than or equal
61 to 'max-value-size', GDB will now still print the array, however only
62 'max-value-size' worth of data will be added into the value history.
64 * For both the break and watch commands, it is now invalid to use both
65 the 'thread' and 'task' keywords within the same command. For
66 example the following commnds will now give an error:
67 break foo thread 1 task 1
68 watch var thread 2 task 3
70 * The printf command now accepts a '%V' output format which will
71 format an expression just as the 'print' command would. Print
72 options can be placed withing '[...]' after the '%V' to modify how
73 the value is printed. E.g:
74 printf "%V", some_array
75 printf "%V[-array-indexes on]", some_array
76 will print the array without, or with array indexes included, just
77 as the array would be printed by the 'print' command. This
78 functionality is also available for dprintf when dprintf-style is
81 * When the printf command requires a string to be fetched from the
82 inferior, GDB now uses the existing 'max-value-size' setting to the
83 limit the memory allocated within GDB. The default 'max-value-size'
84 is 64k. To print longer strings you should increase
87 * The Ada 2022 Enum_Rep and Enum_Val attributes are now supported.
89 * The Ada 2022 target name symbol ('@') is now supported by the Ada
92 * The 'list' command now accepts '.' as an argument, which tells GDB to
93 print the location where the inferior is stopped. If the inferior hasn't
94 started yet, the command will print around the main function.
96 * Using the 'list' command with no arguments in a situation where the
97 command would attempt to list past the end of the file now warns the
98 user that the end of file has been reached, refers the user to the
99 newly added '.' argument
103 set debug breakpoint on|off
104 show debug breakpoint
105 Print additional debug messages about breakpoint insertion and removal.
107 maintenance print record-instruction [ N ]
108 Print the recorded information for a given instruction. If N is not given
109 prints how GDB would undo the last instruction executed. If N is negative,
110 prints how GDB would undo the N-th previous instruction, and if N is
111 positive, it prints how GDB will redo the N-th following instruction.
113 maintenance info frame-unwinders
114 List the frame unwinders currently in effect, starting with the highest
117 maintenance wait-for-index-cache
118 Wait until all pending writes to the index cache have completed.
120 set always-read-ctf on|off
122 When off, CTF is only read if DWARF is not present. When on, CTF is
123 read regardless of whether DWARF is present. Off by default.
126 Get main symbol to identify entry point into program.
128 * New convenience function "$_shell", to execute a shell command and
129 return the result. This lets you run shell commands in expressions.
132 (gdb) p $_shell("true")
134 (gdb) p $_shell("false")
136 (gdb) break func if $_shell("some command") == 0
140 ** mi now reports 'no-history' as a stop reason when hitting the end of the
141 reverse execution history.
143 ** When creating a thread-specific breakpoint using the '-p' option,
144 the -break-insert command would report the 'thread' field twice in
145 the reply. The content of both fields was always identical. This
146 has now been fixed; the 'thread' field will be reported just once
147 for thread-specific breakpoints, or not at all for breakpoints
148 without a thread restriction. The same is also true for the 'task'
149 field of an Ada task-specific breakpoint.
151 ** It is no longer possible to create a thread-specific breakpoint for
152 a thread that doesn't exist using '-break-insert -p ID'. Creating
153 breakpoints for non-existent threads is not allowed when using the
154 CLI, that the MI allowed it was a long standing bug, which has now
157 ** The '--simple-values' argument to the '-stack-list-arguments',
158 '-stack-list-locals', '-stack-list-variables', and '-var-list-children'
159 commands now takes reference types into account: that is, a value is now
160 considered simple if it is neither an array, structure, or union, nor a
161 reference to an array, structure, or union. (Previously all references were
162 considered simple.) Support for this feature can be verified by using the
163 '-list-features' command, which should contain "simple-values-ref-types".
167 ** gdb.ThreadExitedEvent added. Emits a ThreadEvent.
169 ** The gdb.unwinder.Unwinder.name attribute is now read-only.
171 ** The name argument passed to gdb.unwinder.Unwinder.__init__ must
172 now be of type 'str' otherwise a TypeError will be raised.
174 ** The gdb.unwinder.Unwinder.enabled attribute can now only accept
175 values of type 'bool'. Changing this attribute will now
176 invalidate GDB's frame-cache, which means GDB will need to
177 rebuild its frame-cache when next required - either with, or
178 without the particular unwinder, depending on how 'enabled' was
181 ** New methods added to the gdb.PendingFrame class. These methods
182 have the same behaviour as the corresponding methods on
183 gdb.Frame. The new methods are:
185 - gdb.PendingFrame.name: Return the name for the frame's
187 - gdb.PendingFrame.is_valid: Return True if the pending frame
189 - gdb.PendingFrame.pc: Return the $pc register value for this
191 - gdb.PendingFrame.language: Return a string containing the
192 language for this frame, or None.
193 - gdb.PendingFrame.find_sal: Return a gdb.Symtab_and_line
194 object for the current location within the pending frame, or
196 - gdb.PendingFrame.block: Return a gdb.Block for the current
197 pending frame, or None.
198 - gdb.PendingFrame.function: Return a gdb.Symbol for the
199 current pending frame, or None.
201 ** The frame-id passed to gdb.PendingFrame.create_unwind_info can
202 now use either an integer or a gdb.Value object for each of its
203 'sp', 'pc', and 'special' attributes.
205 ** A new class gdb.unwinder.FrameId has been added. Instances of
206 this class are constructed with 'sp' (stack-pointer) and 'pc'
207 (program-counter) values, and can be used as the frame-id when
208 calling gdb.PendingFrame.create_unwind_info.
210 ** It is now no longer possible to sub-class the
211 gdb.disassembler.DisassemblerResult type.
213 ** The Disassembler API from the gdb.disassembler module has been
214 extended to include styling support:
216 - The DisassemblerResult class can now be initialized with a list
217 of parts. Each part represents part of the disassembled
218 instruction along with the associated style information. This
219 list of parts can be accessed with the new
220 DisassemblerResult.parts property.
222 - New constants gdb.disassembler.STYLE_* representing all the
223 different styles part of an instruction might have.
225 - New methods DisassembleInfo.text_part and
226 DisassembleInfo.address_part which are used to create the new
227 styled parts of a disassembled instruction.
229 - Changes are backwards compatible, the older API can still be
230 used to disassemble instructions without styling.
232 ** New function gdb.execute_mi(COMMAND, [ARG]...), that invokes a
233 GDB/MI command and returns the output as a Python dictionary.
235 ** New function gdb.block_signals(). This returns a context manager
236 that blocks any signals that GDB needs to handle itself.
238 ** New class gdb.Thread. This is a subclass of threading.Thread
239 that calls gdb.block_signals in its "start" method.
241 ** gdb.parse_and_eval now has a new "global_context" parameter.
242 This can be used to request that the parse only examine global
245 ** gdb.Inferior now has a new "arguments" attribute. This holds the
246 command-line arguments to the inferior, if known.
248 ** gdb.Inferior now has a new "main_name" attribute. This holds the
249 name of the inferior's "main", if known.
251 ** gdb.Inferior now has new methods "clear_env", "set_env", and
252 "unset_env". These can be used to modify the inferior's
253 environment before it is started.
255 ** gdb.Value now has the 'assign' method.
257 ** gdb.Progspace now has the new method "objfile_for_address". This
258 returns the gdb.Objfile, if any, that covers a given address.
260 *** Changes in GDB 13
262 * MI version 1 is deprecated, and will be removed in GDB 14.
264 * GDB now supports dumping memory tag data for AArch64 MTE. It also supports
265 reading memory tag data for AArch64 MTE from core files generated by
266 the gcore command or the Linux kernel.
268 When a process uses memory-mapped pages protected by memory tags (for
269 example, AArch64 MTE), this additional information will be recorded in
270 the core file in the event of a crash or if GDB generates a core file
271 from the current process state. GDB will show this additional information
272 automatically, or through one of the memory-tag subcommands.
274 * "info breakpoints" now displays enabled breakpoint locations of
275 disabled breakpoints as in the "y-" state. For example:
277 (gdb) info breakpoints
278 Num Type Disp Enb Address What
279 1 breakpoint keep n <MULTIPLE>
280 1.1 y- 0x00000000000011b6 in ...
281 1.2 y- 0x00000000000011c2 in ...
282 1.3 n 0x00000000000011ce in ...
284 * Support for Thread Local Storage (TLS) variables on FreeBSD arm and
285 aarch64 architectures.
287 * GDB now supports hardware watchpoints on FreeBSD/Aarch64.
289 * Remove support for building against Python 2, it is now only possible to
290 build GDB against Python 3.
292 * DBX mode has been removed.
294 * GDB now honours the DWARF prologue_end line-table entry flag the compiler can
295 emit to indicate where a breakpoint should be placed to break in a function
298 * Completion now also offers "NUMBER" for "set" commands that accept
299 a numeric argument and the "unlimited" keyword. For example:
301 (gdb) set width <TAB>
306 (gdb) complete set width
310 * Disassembler styling using libopcodes. GDB now supports
311 disassembler styling using libopcodes. This is only available for
312 some targets (currently x86 and RISC-V). For unsupported targets
313 Python Pygments is still used. For supported targets, libopcodes
314 styling is used by default.
316 * The Windows native target now supports target async.
318 * gdb now supports zstd compressed debug sections (ELFCOMPRESS_ZSTD) for ELF.
320 * The format of 'disassemble /r' and 'record instruction-history /r'
321 has changed. The instruction bytes could now be grouped together,
322 and displayed in the endianness of the instruction. This is the
323 same layout as used by GNU objdump when disassembling.
325 There is now 'disassemble /b' and 'record instruction-history /b'
326 which will always display the instructions bytes one at a time in
327 memory order, that is, the byte at the lowest address first.
329 For both /r and /b GDB is now better at using whitespace in order to
330 align the disassembled instruction text.
332 * The TUI no longer styles the source and assembly code highlighted by
333 the current position indicator by default. You can however
334 re-enable styling using the new "set style tui-current-position"
337 * New convenience variable $_inferior_thread_count contains the number
338 of live threads in the current inferior.
340 * When a breakpoint with multiple code locations is hit, GDB now prints
341 the code location using the syntax <breakpoint_number>.<location_number>
343 Thread 1 "zeoes" hit Breakpoint 2.3, some_func () at zeoes.c:8
345 * When a breakpoint is hit, GDB now sets the convenience variables $_hit_bpnum
346 and $_hit_locno to the hit breakpoint number and code location number.
347 This allows to disable the last hit breakpoint using
348 (gdb) disable $_hit_bpnum
349 or disable only the specific breakpoint code location using
350 (gdb) disable $_hit_bpnum.$_hit_locno
351 These commands can be used inside the command list of a breakpoint to
352 automatically disable the just encountered breakpoint (or the just
353 encountered specific breakpoint code location).
354 When a breakpoint has only one location, $_hit_locno is set to 1 so that
355 (gdb) disable $_hit_bpnum.$_hit_locno
357 (gdb) disable $_hit_bpnum
358 are both disabling the breakpoint.
362 maintenance set ignore-prologue-end-flag on|off
363 maintenance show ignore-prologue-end-flag
364 This setting, which is off by default, controls whether GDB ignores the
365 PROLOGUE-END flag from the line-table when skipping prologue. This can be
366 used to force GDB to use prologue analyzers if the line-table is constructed
367 from erroneous debug information.
369 set print nibbles [on|off]
371 This controls whether the 'print/t' command will display binary values
372 in groups of four bits, known as "nibbles". The default is 'off'.
374 maintenance set libopcodes-styling on|off
375 maintenance show libopcodes-styling
376 These can be used to force off libopcodes based styling, the Python
377 Pygments styling will then be used instead.
379 set style disassembler comment
380 show style disassembler comment
381 set style disassembler immediate
382 show style disassembler immediate
383 set style disassembler mnemonic
384 show style disassembler mnemonic
385 set style disassembler register
386 show style disassembler register
387 set style disassembler address
388 show style disassembler address
389 set style disassembler symbol
390 show style disassembler symbol
391 For targets that support libopcodes based styling, these settings
392 control how various aspects of the disassembler output are styled.
393 The 'disassembler address' and 'disassembler symbol' styles are
394 aliases for the 'address' and 'function' styles respectively.
396 maintenance print frame-id [ LEVEL ]
397 Print GDB's internal frame-id for the frame at LEVEL. If LEVEL is
398 not given, then print the frame-id for the currently selected frame.
400 set debug infcall on|off
402 Print additional debug messages about inferior function calls.
404 set debug solib on|off
406 Print additional debug messages about shared library handling.
408 set style tui-current-position [on|off]
409 Whether to style the source and assembly code highlighted by the
410 TUI's current position indicator. The default is off.
412 set print characters LIMIT
413 show print characters
414 This new setting is like 'set print elements', but controls how many
415 characters of a string are printed. This functionality used to be
416 covered by 'set print elements', but it can be controlled separately
417 now. LIMIT can be set to a numerical value to request that particular
418 character count, to 'unlimited' to print all characters of a string,
419 or to 'elements', which is also the default, to follow the setting of
420 'set print elements' as it used to be.
422 print -characters LIMIT
423 This new option to the 'print' command has the same effect as a temporary
424 use of 'set print characters'.
428 document user-defined
429 It is now possible to document user-defined aliases.
430 When a user-defined alias is documented, the help and apropos commands
431 use the provided documentation instead of the documentation of the
433 Documenting a user-defined alias is particularly useful when the alias
434 is a set of nested 'with' commands to avoid showing the help of
435 the with command for an alias that will in fact launch the
436 last command given in the nested commands.
438 maintenance info line-table
439 Add a PROLOGUE-END column to the output which indicates that an
440 entry corresponds to an address where a breakpoint should be placed
441 to be at the first instruction past a function's prologue.
445 set debug aix-solib on|off
447 set debug solib-frv on|off
449 Removed in favor of "set/show debug solib".
451 maintenance info program-spaces
452 This command now includes a 'Core File' column which indicates the
453 name of the core file associated with each program space.
457 GNU/Linux/LoongArch (gdbserver) loongarch*-*-linux*
459 GNU/Linux/CSKY (gdbserver) csky*-*linux*
465 ** The async record stating the stopped reason 'breakpoint-hit' now
466 contains an optional field locno giving the code location number
467 when the breakpoint has multiple code locations.
471 ** GDB will now reformat the doc string for gdb.Command and
472 gdb.Parameter sub-classes to remove unnecessary leading
473 whitespace from each line before using the string as the help
476 ** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
477 that formats ADDRESS as 'address <symbol+offset>', where symbol is
478 looked up in PROGSPACE, and ARCHITECTURE is used to format address.
479 This is the same format that GDB uses when printing address, symbol,
480 and offset information from the disassembler.
482 ** New function gdb.current_language that returns the name of the
483 current language. Unlike gdb.parameter('language'), this will
486 ** New method gdb.Frame.language that returns the name of the
489 ** New Python API for wrapping GDB's disassembler:
491 - gdb.disassembler.register_disassembler(DISASSEMBLER, ARCH).
492 DISASSEMBLER is a sub-class of gdb.disassembler.Disassembler.
493 ARCH is either None or a string containing a bfd architecture
494 name. DISASSEMBLER is registered as a disassembler for
495 architecture ARCH, or for all architectures if ARCH is None.
496 The previous disassembler registered for ARCH is returned, this
497 can be None if no previous disassembler was registered.
499 - gdb.disassembler.Disassembler is the class from which all
500 disassemblers should inherit. Its constructor takes a string,
501 a name for the disassembler, which is currently only used in
502 some debug output. Sub-classes should override the __call__
503 method to perform disassembly, invoking __call__ on this base
504 class will raise an exception.
506 - gdb.disassembler.DisassembleInfo is the class used to describe
507 a single disassembly request from GDB. An instance of this
508 class is passed to the __call__ method of
509 gdb.disassembler.Disassembler and has the following read-only
510 attributes: 'address', and 'architecture', as well as the
511 following method: 'read_memory'.
513 - gdb.disassembler.builtin_disassemble(INFO, MEMORY_SOURCE),
514 calls GDB's builtin disassembler on INFO, which is a
515 gdb.disassembler.DisassembleInfo object. MEMORY_SOURCE is
516 optional, its default value is None. If MEMORY_SOURCE is not
517 None then it must be an object that has a 'read_memory' method.
519 - gdb.disassembler.DisassemblerResult is a class that can be used
520 to wrap the result of a call to a Disassembler. It has
521 read-only attributes 'length' and 'string'.
523 ** gdb.Objfile now has an attribute named "is_file". This is True
524 if the objfile comes from a file, and False otherwise.
526 ** New function gdb.print_options that returns a dictionary of the
527 prevailing print options, in the form accepted by
528 gdb.Value.format_string.
530 ** gdb.Value.format_string now uses the format provided by 'print',
531 if it is called during a 'print' or other similar operation.
533 ** gdb.Value.format_string now accepts the 'summary' keyword. This
534 can be used to request a shorter representation of a value, the
535 way that 'set print frame-arguments scalars' does.
537 ** New Python type gdb.BreakpointLocation.
538 The new attribute 'locations' of gdb.Breakpoint returns a list of
539 gdb.BreakpointLocation objects specifying the locations where the
540 breakpoint is inserted into the debuggee.
542 ** The gdb.register_window_type method now restricts the set of
543 acceptable window names. The first character of a window's name
544 must start with a character in the set [a-zA-Z], every subsequent
545 character of a window's name must be in the set [-_.a-zA-Z0-9].
547 * New features in the GDB remote stub, GDBserver
549 ** GDBserver is now supported on LoongArch GNU/Linux.
551 ** GDBserver is now supported on CSKY GNU/Linux.
553 * LoongArch floating-point support
555 GDB now supports floating-point on LoongArch GNU/Linux.
557 * AMD GPU ROCm debugging support
559 GDB now supports debugging programs offloaded to AMD GPUs using the ROCm
562 *** Changes in GDB 12
564 * DBX mode is deprecated, and will be removed in GDB 13
566 * GDB 12 is the last release of GDB that will support building against
567 Python 2. From GDB 13, it will only be possible to build GDB itself
568 with Python 3 support.
570 * The disable-randomization setting now works on Windows.
572 * Improved C++ template support
574 GDB now treats functions/types involving C++ templates like it does function
575 overloads. Users may omit parameter lists to set breakpoints on families of
576 template functions, including types/functions composed of multiple template types:
578 (gdb) break template_func(template_1, int)
580 The above will set breakpoints at every function `template_func' where
581 the first function parameter is any template type named `template_1' and
582 the second function parameter is `int'.
584 TAB completion also gains similar improvements.
586 * The FreeBSD native target now supports async mode.
592 Enable or disable multithreaded symbol loading. This is enabled
593 by default, but passing --disable-threading or --enable-threading=no
594 to configure will disable it.
596 Disabling this can cause a performance penalty when there are a lot of
597 symbols to load, but is useful for debugging purposes.
601 maint set backtrace-on-fatal-signal on|off
602 maint show backtrace-on-fatal-signal
603 This setting is 'on' by default. When 'on' GDB will print a limited
604 backtrace to stderr in the situation where GDB terminates with a
605 fatal signal. This only supported on some platforms where the
606 backtrace and backtrace_symbols_fd functions are available.
608 set source open on|off
610 This setting, which is on by default, controls whether GDB will try
611 to open source code files. Switching this off will stop GDB trying
612 to open and read source code files, which can be useful if the files
613 are located over a slow network connection.
617 These are now deprecated aliases for "set max-value-size" and
618 "show max-value-size".
620 task apply [all | TASK-IDS...] [FLAG]... COMMAND
621 Like "thread apply", but applies COMMAND to Ada tasks.
624 Watchpoints can now be restricted to a specific Ada task.
626 maint set internal-error backtrace on|off
627 maint show internal-error backtrace
628 maint set internal-warning backtrace on|off
629 maint show internal-warning backtrace
630 GDB can now print a backtrace of itself when it encounters either an
631 internal-error, or an internal-warning. This is on by default for
632 internal-error and off by default for internal-warning.
635 Deprecated and replaced by "set logging enabled on|off".
637 set logging enabled on|off
639 These commands set or show whether logging is enabled or disabled.
642 You can now exit GDB by using the new command "exit", in addition to
643 the existing "quit" command.
645 set debug threads on|off
647 Print additional debug messages about thread creation and deletion.
649 set debug linux-nat on|off
651 These new commands replaced the old 'set debug lin-lwp' and 'show
652 debug lin-lwp' respectively. Turning this setting on prints debug
653 messages relating to GDB's handling of native Linux inferiors.
655 maint flush source-cache
656 Flush the contents of the source code cache.
658 maint set gnu-source-highlight enabled on|off
659 maint show gnu-source-highlight enabled
660 Whether GDB should use the GNU Source Highlight library for adding
661 styling to source code. When off, the library will not be used, even
662 when available. When GNU Source Highlight isn't used, or can't add
663 styling to a particular source file, then the Python Pygments
664 library will be used instead.
666 set suppress-cli-notifications (on|off)
667 show suppress-cli-notifications
668 This controls whether printing the notifications is suppressed for CLI.
669 CLI notifications occur when you change the selected context
670 (i.e., the current inferior, thread and/or the frame), or when
671 the program being debugged stops (e.g., because of hitting a
672 breakpoint, completing source-stepping, an interrupt, etc.).
674 set style disassembler enabled on|off
675 show style disassembler enabled
676 If GDB is compiled with Python support, and the Python Pygments
677 package is available, then, when this setting is on, disassembler
678 output will have styling applied.
680 set ada source-charset
681 show ada source-charset
682 Set the character set encoding that is assumed for Ada symbols. Valid
683 values for this follow the values that can be passed to the GNAT
684 compiler via the '-gnati' option. The default is ISO-8859-1.
690 These are the new names for the old 'layout', 'focus', 'refresh',
691 and 'winheight' tui commands respectively. The old names still
692 exist as aliases to these new commands.
696 The new command 'tui window width', and the alias 'winwidth' allow
697 the width of a tui window to be adjusted when windows are laid out
702 Control the display of debug output about GDB's tui.
707 Printing of floating-point values with base-modifying formats like
708 /x has been changed to display the underlying bytes of the value in
709 the desired base. This was GDB's documented behavior, but was never
710 implemented correctly.
713 This command can now print a reply, if the reply includes
714 non-printable characters. Any non-printable characters are printed
715 as escaped hex, e.g. \x?? where '??' is replaces with the value of
716 the non-printable character.
719 The clone-inferior command now ensures that the TTY, CMD and ARGS
720 settings are copied from the original inferior to the new one.
721 All modifications to the environment variables done using the 'set
722 environment' or 'unset environment' commands are also copied to the new
725 set debug lin-lwp on|off
727 These commands have been removed from GDB. The new command 'set
728 debug linux-nat' and 'show debug linux-nat' should be used
732 This command now includes information about the width of the tui
733 windows in its output.
739 These commands are now aliases for the 'tui layout', 'tui focus',
740 'tui refresh', and 'tui window height' commands respectively.
742 * GDB's Ada parser now supports an extension for specifying the exact
743 byte contents of a floating-point literal. This can be useful for
744 setting floating-point registers to a precise value without loss of
745 precision. The syntax is an extension of the based literal syntax.
746 Use, e.g., "16lf#0123abcd#" -- the number of "l"s controls the width
747 of the floating-point type, and the "f" is the marker for floating
752 ** The '-add-inferior' with no option flags now inherits the
753 connection of the current inferior, this restores the behaviour of
754 GDB as it was prior to GDB 10.
756 ** The '-add-inferior' command now accepts a '--no-connection'
757 option, which causes the new inferior to start without a
760 ** The default version of the MI interpreter is now 4 (-i=mi4).
762 ** The "script" field in breakpoint output (which is syntactically
763 incorrect in MI 3 and below) has changed in MI 4 to become a list.
764 This affects the following commands and events:
768 - =breakpoint-created
769 - =breakpoint-modified
771 The -fix-breakpoint-script-output command can be used to enable
772 this behavior with previous MI versions.
776 GNU/Linux/LoongArch loongarch*-*-linux*
784 ** New function gdb.add_history(), which takes a gdb.Value object
785 and adds the value it represents to GDB's history list. An
786 integer, the index of the new item in the history list, is
789 ** New function gdb.history_count(), which returns the number of
790 values in GDB's value history.
792 ** New gdb.events.gdb_exiting event. This event is called with a
793 gdb.GdbExitingEvent object which has the read-only attribute
794 'exit_code', which contains the value of the GDB exit code. This
795 event is triggered once GDB decides it is going to exit, but
796 before GDB starts to clean up its internal state.
798 ** New function gdb.architecture_names(), which returns a list
799 containing all of the possible Architecture.name() values. Each
802 ** New function gdb.Architecture.integer_type(), which returns an
803 integer type given a size and a signed-ness.
805 ** New gdb.TargetConnection object type that represents a connection
806 (as displayed by the 'info connections' command). A sub-class,
807 gdb.RemoteTargetConnection, is used to represent 'remote' and
808 'extended-remote' connections.
810 ** The gdb.Inferior type now has a 'connection' property which is an
811 instance of gdb.TargetConnection, the connection used by this
812 inferior. This can be None if the inferior has no connection.
814 ** New 'gdb.events.connection_removed' event registry, which emits a
815 'gdb.ConnectionEvent' when a connection is removed from GDB.
816 This event has a 'connection' property, a gdb.TargetConnection
817 object for the connection being removed.
819 ** New gdb.connections() function that returns a list of all
820 currently active connections.
822 ** New gdb.RemoteTargetConnection.send_packet(PACKET) method. This
823 is equivalent to the existing 'maint packet' CLI command; it
824 allows a user specified packet to be sent to the remote target.
826 ** New function gdb.host_charset(), returns a string, which is the
827 name of the current host charset.
829 ** New gdb.set_parameter(NAME, VALUE). This sets the gdb parameter
832 ** New gdb.with_parameter(NAME, VALUE). This returns a context
833 manager that temporarily sets the gdb parameter NAME to VALUE,
834 then resets it when the context is exited.
836 ** The gdb.Value.format_string method now takes a 'styling'
837 argument, which is a boolean. When true, the returned string can
838 include escape sequences to apply styling. The styling will only
839 be present if styling is otherwise turned on in GDB (see 'help
840 set styling'). When false, which is the default if the argument
841 is not given, then no styling is applied to the returned string.
843 ** New read-only attribute gdb.InferiorThread.details, which is
844 either a string, containing additional, target specific thread
845 state information, or None, if there is no such additional
848 ** New read-only attribute gdb.Type.is_scalar, which is True for
849 scalar types, and False for all other types.
851 ** New read-only attribute gdb.Type.is_signed. This attribute
852 should only be read when Type.is_scalar is True, and will be True
853 for signed types, and False for all other types. Attempting to
854 read this attribute for non-scalar types will raise a ValueError.
856 ** It is now possible to add GDB/MI commands implemented in Python.
858 * New features in the GDB remote stub, GDBserver
860 ** GDBserver is now supported on OpenRISC GNU/Linux.
862 * New native configurations
864 GNU/Linux/OpenRISC or1k*-*-linux*
866 *** Changes in GDB 11
868 * The 'set disassembler-options' command now supports specifying options
871 * GDB now supports general memory tagging functionality if the underlying
872 architecture supports the proper primitives and hooks. Currently this is
873 enabled only for AArch64 MTE.
877 - Additional information when the inferior crashes with a SIGSEGV caused by
878 a memory tag violation.
880 - A new modifier 'm' for the "x" command, which displays allocation tags for a
881 particular memory range.
883 - Display of memory tag mismatches by "print", for addresses and
884 pointers, if memory tagging is supported by the architecture.
886 * Building GDB now requires GMP (The GNU Multiple Precision Arithmetic
891 ** '-break-insert --qualified' and '-dprintf-insert --qualified'
893 The MI -break-insert and -dprintf-insert commands now support a
894 new "--qualified" option that makes GDB interpret a specified
895 function name as a complete fully-qualified name. This is the
896 equivalent of the CLI's "break -qualified" and "dprintf
899 ** '-break-insert --force-condition' and '-dprintf-insert --force-condition'
901 The MI -break-insert and -dprintf-insert commands now support a
902 '--force-condition' flag to forcibly define a condition even when
903 the condition is invalid at all locations of the breakpoint. This
904 is equivalent to the '-force-condition' flag of the CLI's "break"
907 ** '-break-condition --force'
909 The MI -break-condition command now supports a '--force' flag to
910 forcibly define a condition even when the condition is invalid at
911 all locations of the selected breakpoint. This is equivalent to
912 the '-force' flag of the CLI's "cond" command.
914 ** '-file-list-exec-source-files [--group-by-objfile]
915 [--basename | --dirname]
918 The existing -file-list-exec-source-files command now takes an
919 optional REGEXP which is used to filter the source files that are
920 included in the results.
922 By default REGEXP is matched against the full filename of the
923 source file. When one of --basename or --dirname is given then
924 REGEXP is only matched against the specified part of the full
927 When the optional --group-by-objfile flag is used the output
928 format is changed, the results are now a list of object files
929 (executable and libraries) with the source files that are
930 associated with each object file.
932 The results from -file-list-exec-source-files now include a
933 'debug-fully-read' field which takes the value 'true' or 'false'.
934 A 'true' value indicates the source file is from a compilation
935 unit that has had its debug information fully read in by GDB, a
936 value of 'false' indicates GDB has only performed a partial scan
937 of the debug information so far.
939 * GDB now supports core file debugging for x86_64 Cygwin programs.
941 * GDB will now look for the .gdbinit file in a config directory before
942 looking for ~/.gdbinit. The file is searched for in the following
943 locations: $XDG_CONFIG_HOME/gdb/gdbinit, $HOME/.config/gdb/gdbinit,
944 $HOME/.gdbinit. On Apple hosts the search order is instead:
945 $HOME/Library/Preferences/gdb/gdbinit, $HOME/.gdbinit.
947 * GDB now supports fixed point types which are described in DWARF
948 as base types with a fixed-point encoding. Additionally, support
949 for the DW_AT_GNU_numerator and DW_AT_GNU_denominator has also
952 For Ada, this allows support for fixed point types without requiring
953 the use of the GNAT encoding (based on information added to the type's
954 name following a GNAT-specific format).
956 * GDB will now load and process commands from ~/.config/gdb/gdbearlyinit
957 or ~/.gdbearlyinit if these files are present. These files are
958 processed earlier than any of the other initialization files and
959 can affect parts of GDB's startup that previously had already been
960 completed before the initialization files were read, for example
961 styling of the initial GDB greeting.
963 * GDB now has two new options "--early-init-command" and
964 "--early-init-eval-command" with corresponding short options "-eix"
965 and "-eiex" that allow options (that would normally appear in a
966 gdbearlyinit file) to be passed on the command line.
968 * For RISC-V targets, the target feature "org.gnu.gdb.riscv.vector" is
969 now understood by GDB, and can be used to describe the vector
970 registers of a target. The precise requirements of this register
971 feature are documented in the GDB manual.
973 * For ARM targets, the "org.gnu.gdb.arm.m-profile-mve" feature is now
974 supported by GDB and describes a new VPR register from the ARM MVE
975 (Helium) extension. See the GDB manual for more information.
979 ** TUI windows now support mouse actions. The mouse wheel scrolls
980 the appropriate window.
982 ** Key combinations that do not have a specific action on the
983 focused window are passed to GDB. For example, you now can use
984 Ctrl-Left/Ctrl-Right to move between words in the command window
985 regardless of which window is in focus. Previously you would
986 need to focus on the command window for such key combinations to
992 show debug event-loop
993 Control the display of debug output about GDB's event loop.
995 set print memory-tag-violations
996 show print memory-tag-violations
997 Control whether to display additional information about memory tag violations
998 when printing pointers and addresses. Architecture support for memory
999 tagging is required for this option to have an effect.
1001 maintenance flush symbol-cache
1002 maintenance flush register-cache
1003 These new commands are equivalent to the already existing commands
1004 'maintenance flush-symbol-cache' and 'flushregs' respectively.
1006 maintenance flush dcache
1007 A new command to flush the dcache.
1009 maintenance info target-sections
1010 Print GDB's internal target sections table.
1012 maintenance info jit
1013 Print the JIT code objects in the inferior known to GDB.
1015 memory-tag show-logical-tag POINTER
1016 Print the logical tag for POINTER.
1017 memory-tag with-logical-tag POINTER TAG
1018 Print POINTER with logical tag TAG.
1019 memory-tag show-allocation-tag ADDRESS
1020 Print the allocation tag for ADDRESS.
1021 memory-tag set-allocation-tag ADDRESS LENGTH TAGS
1022 Set the allocation tag for [ADDRESS, ADDRESS + LENGTH) to TAGS.
1023 memory-tag check POINTER
1024 Validate that POINTER's logical tag matches the allocation tag.
1026 set startup-quietly on|off
1027 show startup-quietly
1028 When 'on', this causes GDB to act as if "-silent" were passed on the
1029 command line. This command needs to be added to an early
1030 initialization file (e.g. ~/.config/gdb/gdbearlyinit) in order to
1033 set print type hex on|off
1035 When 'on', the 'ptype' command uses hexadecimal notation to print sizes
1036 and offsets of struct members. When 'off', decimal notation is used.
1038 set python ignore-environment on|off
1039 show python ignore-environment
1040 When 'on', this causes GDB's builtin Python to ignore any
1041 environment variables that would otherwise affect how Python
1042 behaves. This command needs to be added to an early initialization
1043 file (e.g. ~/.config/gdb/gdbearlyinit) in order to affect GDB.
1045 set python dont-write-bytecode auto|on|off
1046 show python dont-write-bytecode
1047 When 'on', this causes GDB's builtin Python to not write any
1048 byte-code (.pyc files) to disk. This command needs to be added to
1049 an early initialization file (e.g. ~/.config/gdb/gdbearlyinit) in
1050 order to affect GDB. When 'off' byte-code will always be written.
1051 When set to 'auto' (the default) Python will check the
1052 PYTHONDONTWRITEBYTECODE environment variable.
1056 break [PROBE_MODIFIER] [LOCATION] [thread THREADNUM]
1057 [-force-condition] [if CONDITION]
1058 This command would previously refuse setting a breakpoint if the
1059 CONDITION expression is invalid at a location. It now accepts and
1060 defines the breakpoint if there is at least one location at which
1061 the CONDITION is valid. The locations for which the CONDITION is
1062 invalid, are automatically disabled. If CONDITION is invalid at all
1063 of the locations, setting the breakpoint is still rejected. However,
1064 the '-force-condition' flag can be used in this case for forcing GDB to
1065 define the breakpoint, making all the current locations automatically
1066 disabled. This may be useful if the user knows the condition will
1067 become meaningful at a future location, e.g. due to a shared library
1070 condition [-force] N COND
1071 The behavior of this command is changed the same way for the 'break'
1072 command as explained above. The '-force' flag can be used to force
1073 GDB into defining the condition even when COND is invalid for all the
1074 current locations of breakpoint N.
1077 maintenance flush-symbol-cache
1078 These commands are deprecated in favor of the new commands
1079 'maintenance flush register-cache' and 'maintenance flush
1080 symbol-cache' respectively.
1082 set style version foreground COLOR
1083 set style version background COLOR
1084 set style version intensity VALUE
1085 Control the styling of GDB's version number text.
1088 When the ID parameter is omitted, then this command prints information
1089 about the current inferior. When the ID parameter is present, the
1090 behavior of the command is unchanged and have the inferior ID become
1091 the current inferior.
1093 maintenance info sections
1094 The ALLOBJ keyword has been replaced with an -all-objects command
1095 line flag. It is now possible to filter which sections are printed
1096 even when -all-objects is passed.
1098 ptype[/FLAGS] TYPE | EXPRESSION
1099 The 'ptype' command has two new flags. When '/x' is set, hexadecimal
1100 notation is used when printing sizes and offsets of struct members.
1101 When '/d' is set, decimal notation is used when printing sizes and
1102 offsets of struct members. Default behavior is given by 'show print
1106 The info sources command output has been restructured. The results
1107 are now based around a list of objfiles (executable and libraries),
1108 and for each objfile the source files that are part of that objfile
1111 * Removed targets and native configurations
1113 ARM Symbian arm*-*-symbianelf*
1115 * New remote packets
1118 Request the remote to send allocation tags for a particular memory range.
1120 Request the remote to store the specified allocation tags to the requested
1125 ** Improved support for rvalue reference values:
1126 TYPE_CODE_RVALUE_REF is now exported as part of the API and the
1127 value-referenced-value procedure now handles rvalue reference
1130 ** New procedures for obtaining value variants:
1131 value-reference-value, value-rvalue-reference-value and
1134 ** Temporary breakpoints can now be created with make-breakpoint and
1135 tested for using breakpoint-temporary?.
1139 ** Inferior objects now contain a read-only 'connection_num' attribute that
1140 gives the connection number as seen in 'info connections' and
1143 ** New method gdb.Frame.level() which returns the stack level of the
1146 ** New method gdb.PendingFrame.level() which returns the stack level
1147 of the frame object.
1149 ** When hitting a catchpoint, the Python API will now emit a
1150 gdb.BreakpointEvent rather than a gdb.StopEvent. The
1151 gdb.Breakpoint attached to the event will have type BP_CATCHPOINT.
1153 ** Python TUI windows can now receive mouse click events. If the
1154 Window object implements the click method, it is called for each
1155 mouse click event in this window.
1157 *** Changes in GDB 10
1159 * There are new feature names for ARC targets: "org.gnu.gdb.arc.core"
1160 and "org.gnu.gdb.arc.aux". The old names are still supported but
1161 must be considered obsolete. They will be deprecated after some
1164 * Help and apropos commands will now show the documentation of a
1165 command only once, even if that command has one or more aliases.
1166 These commands now show the command name, then all of its aliases,
1167 and finally the description of the command.
1169 * 'help aliases' now shows only the user defined aliases. GDB predefined
1170 aliases are shown together with their aliased command.
1172 * GDB now supports debuginfod, an HTTP server for distributing ELF/DWARF
1173 debugging information as well as source code.
1175 When built with debuginfod, GDB can automatically query debuginfod
1176 servers for the separate debug files and source code of the executable
1179 To build GDB with debuginfod, pass --with-debuginfod to configure (this
1180 requires libdebuginfod, the debuginfod client library).
1182 debuginfod is distributed with elfutils, starting with version 0.178.
1184 You can get the latest version from https://sourceware.org/elfutils.
1186 * Multi-target debugging support
1188 GDB now supports debugging multiple target connections
1189 simultaneously. For example, you can now have each inferior
1190 connected to different remote servers running in different machines,
1191 or have one inferior debugging a local native process, an inferior
1192 debugging a core dump, etc.
1194 This support is experimental and comes with some limitations -- you
1195 can only resume multiple targets simultaneously if all targets
1196 support non-stop mode, and all remote stubs or servers must support
1197 the same set of remote protocol features exactly. See also "info
1198 connections" and "add-inferior -no-connection" below, and "maint set
1199 target-non-stop" in the user manual.
1201 * New features in the GDB remote stub, GDBserver
1203 ** GDBserver is now supported on ARC GNU/Linux.
1205 ** GDBserver is now supported on RISC-V GNU/Linux.
1207 ** GDBserver no longer supports these host triplets:
1209 i[34567]86-*-lynxos*
1218 i[34567]86-*-mingw32ce*
1220 * Debugging MS-Windows processes now sets $_exitsignal when the
1221 inferior is terminated by a signal, instead of setting $_exitcode.
1223 * Multithreaded symbol loading has now been enabled by default on systems
1224 that support it (see entry for GDB 9, below), providing faster
1225 performance for programs with many symbols.
1227 * The $_siginfo convenience variable now also works on Windows targets,
1228 and will display the EXCEPTION_RECORD of the last handled exception.
1230 * TUI windows can now be arranged horizontally.
1232 * The command history filename can now be set to the empty string
1233 either using 'set history filename' or by setting 'GDBHISTFILE=' in
1234 the environment. The effect of setting this filename to the empty
1235 string is that GDB will not try to load any previous command
1238 * On Windows targets, it is now possible to debug 32-bit programs with a
1243 set exec-file-mismatch -- Set exec-file-mismatch handling (ask|warn|off).
1244 show exec-file-mismatch -- Show exec-file-mismatch handling (ask|warn|off).
1245 Set or show the option 'exec-file-mismatch'. When GDB attaches to a
1246 running process, this new option indicates whether to detect
1247 a mismatch between the current executable file loaded by GDB and the
1248 executable file used to start the process. If 'ask', the default,
1249 display a warning and ask the user whether to load the process
1250 executable file; if 'warn', just display a warning; if 'off', don't
1251 attempt to detect a mismatch.
1253 tui new-layout NAME WINDOW WEIGHT [WINDOW WEIGHT]...
1254 Define a new TUI layout, specifying its name and the windows that
1257 maintenance print xml-tdesc [FILE]
1258 Prints the current target description as an XML document. If the
1259 optional FILE is provided (which is an XML target description) then
1260 the target description is read from FILE into GDB, and then
1263 maintenance print core-file-backed-mappings
1264 Prints file-backed mappings loaded from a core file's note section.
1265 Output is expected to be similar to that of "info proc mappings".
1267 set debug fortran-array-slicing on|off
1268 show debug fortran-array-slicing
1269 Print debugging when taking slices of Fortran arrays.
1271 set fortran repack-array-slices on|off
1272 show fortran repack-array-slices
1273 When taking slices from Fortran arrays and strings, if the slice is
1274 non-contiguous within the original value then, when this option is
1275 on, the new value will be repacked into a single contiguous value.
1276 When this option is off, then the value returned will consist of a
1277 descriptor that describes the slice within the memory of the
1278 original parent value.
1282 alias [-a] [--] ALIAS = COMMAND [DEFAULT-ARGS...]
1283 The alias command can now specify default args for an alias.
1284 GDB automatically prepends the alias default args to the argument list
1285 provided explicitly by the user.
1286 For example, to have a backtrace with full details, you can define
1287 an alias 'bt_ALL' as
1288 'alias bt_ALL = backtrace -entry-values both -frame-arg all
1289 -past-main -past-entry -full'.
1290 Alias default arguments can also use a set of nested 'with' commands,
1291 e.g. 'alias pp10 = with print pretty -- with print elem 10 -- print'
1292 defines the alias pp10 that will pretty print a maximum of 10 elements
1293 of the given expression (if the expression is an array).
1297 GNU/Linux/RISC-V (gdbserver) riscv*-*-linux*
1298 BPF bpf-unknown-none
1303 ** gdb.register_window_type can be used to implement new TUI windows
1306 ** Dynamic types can now be queried. gdb.Type has a new attribute,
1307 "dynamic", and gdb.Type.sizeof can be None for a dynamic type. A
1308 field of a dynamic type may have None for its "bitpos" attribute
1311 ** Commands written in Python can be in the "TUI" help class by
1312 registering with the new constant gdb.COMMAND_TUI.
1314 ** New method gdb.PendingFrame.architecture () to retrieve the
1315 architecture of the pending frame.
1317 ** New gdb.Architecture.registers method that returns a
1318 gdb.RegisterDescriptorIterator object, an iterator that returns
1319 gdb.RegisterDescriptor objects. The new RegisterDescriptor is a
1320 way to query the registers available for an architecture.
1322 ** New gdb.Architecture.register_groups method that returns a
1323 gdb.RegisterGroupIterator object, an iterator that returns
1324 gdb.RegisterGroup objects. The new RegisterGroup is a way to
1325 discover the available register groups.
1329 ** GDB can now be built with GNU Guile 3.0 and 2.2 in addition to 2.0.
1331 ** Procedures 'memory-port-read-buffer-size',
1332 'set-memory-port-read-buffer-size!', 'memory-port-write-buffer-size',
1333 and 'set-memory-port-write-buffer-size!' are deprecated. When
1334 using Guile 2.2 and later, users who need to control the size of
1335 a memory port's internal buffer can use the 'setvbuf' procedure.
1337 *** Changes in GDB 9
1339 * 'thread-exited' event is now available in the annotations interface.
1341 * New built-in convenience variables $_gdb_major and $_gdb_minor
1342 provide the GDB version. They are handy for conditionally using
1343 features available only in or since specific GDB versions, in
1344 scripts that should work error-free with many different versions,
1345 such as in system-wide init files.
1347 * New built-in convenience functions $_gdb_setting, $_gdb_setting_str,
1348 $_gdb_maint_setting and $_gdb_maint_setting_str provide access to values
1349 of the GDB settings and the GDB maintenance settings. They are handy
1350 for changing the logic of user defined commands depending on the
1351 current GDB settings.
1353 * GDB now supports Thread Local Storage (TLS) variables on several
1354 FreeBSD architectures (amd64, i386, powerpc, riscv). Other
1355 architectures require kernel changes. TLS is not yet supported for
1356 amd64 and i386 process core dumps.
1358 * Support for Pointer Authentication (PAC) on AArch64 Linux. Return
1359 addresses that required unmasking are shown in the backtrace with the
1362 * Two new convenience functions $_cimag and $_creal that extract the
1363 imaginary and real parts respectively from complex numbers.
1365 * New built-in convenience variables $_shell_exitcode and $_shell_exitsignal
1366 provide the exitcode or exit status of the shell commands launched by
1367 GDB commands such as "shell", "pipe" and "make".
1369 * The command define-prefix can now define user defined prefix commands.
1370 User defined commands can now be defined using these user defined prefix
1373 * Command names can now use the . character.
1375 * The RX port now supports XML target descriptions.
1377 * GDB now shows the Ada task names at more places, e.g. in task switching
1380 * GDB can now be compiled with Python 3 on Windows.
1382 * New convenience variable $_ada_exception holds the address of the
1383 Ada exception being thrown. This is set by Ada-related catchpoints.
1385 * GDB can now place breakpoints on nested functions and subroutines in
1386 Fortran code. The '::' operator can be used between parent and
1387 child scopes when placing breakpoints, for example:
1389 (gdb) break outer_function::inner_function
1391 The 'outer_function::' prefix is only needed if 'inner_function' is
1392 not visible in the current scope.
1394 * In addition to the system-wide gdbinit file, if configured with
1395 --with-system-gdbinit-dir, GDB will now also load files in that directory
1396 as system gdbinit files, unless the -nx or -n flag is provided. Files
1397 with extensions .gdb, .py and .scm are supported as long as GDB was
1398 compiled with support for that language.
1400 * GDB now supports multithreaded symbol loading for higher performance.
1401 This feature is still in testing, so it is disabled by default. You
1402 can turn it on using 'maint set worker-threads unlimited'.
1406 ** The gdb.Value type has a new method 'format_string' which returns a
1407 string representing the value. The formatting is controlled by the
1408 optional keyword arguments: 'raw', 'pretty_arrays', 'pretty_structs',
1409 'array_indexes', 'symbols', 'unions', 'deref_refs', 'actual_objects',
1410 'static_members', 'max_elements', 'repeat_threshold', and 'format'.
1412 ** gdb.Type has a new property 'objfile' which returns the objfile the
1413 type was defined in.
1415 ** The frame information printed by the python frame filtering code
1416 is now consistent with what the 'backtrace' command prints when
1417 there are no filters, or when the 'backtrace' '-no-filters' option
1420 ** The new function gdb.lookup_static_symbol can be used to look up
1421 symbols with static linkage.
1423 ** The new function gdb.lookup_static_symbols can be used to look up
1424 all static symbols with static linkage.
1426 ** gdb.Objfile has new methods 'lookup_global_symbol' and
1427 'lookup_static_symbol' to lookup a symbol from this objfile only.
1429 ** gdb.Block now supports the dictionary syntax for accessing symbols in
1430 this block (e.g. block['local_variable']).
1434 | [COMMAND] | SHELL_COMMAND
1435 | -d DELIM COMMAND DELIM SHELL_COMMAND
1436 pipe [COMMAND] | SHELL_COMMAND
1437 pipe -d DELIM COMMAND DELIM SHELL_COMMAND
1438 Executes COMMAND and sends its output to SHELL_COMMAND.
1439 With no COMMAND, repeat the last executed command
1440 and send its output to SHELL_COMMAND.
1442 define-prefix COMMAND
1443 Define or mark a command as a user-defined prefix command.
1445 with SETTING [VALUE] [-- COMMAND]
1446 w SETTING [VALUE] [-- COMMAND]
1447 Temporarily set SETTING, run COMMAND, and restore SETTING.
1448 Usage: with SETTING -- COMMAND
1449 With no COMMAND, repeats the last executed command.
1450 SETTING is any GDB setting you can change with the "set"
1451 subcommands. For example, 'with language c -- print someobj'
1452 temporarily switches to the C language in order to print someobj.
1453 Settings can be combined: 'w lang c -- w print elements unlimited --
1454 usercmd' switches to the C language and runs usercmd with no limit
1455 of array elements to print.
1457 maint with SETTING [VALUE] [-- COMMAND]
1458 Like "with", but works with "maintenance set" settings.
1460 set may-call-functions [on|off]
1461 show may-call-functions
1462 This controls whether GDB will attempt to call functions in
1463 the program, such as with expressions in the print command. It
1464 defaults to on. Calling functions in the program being debugged
1465 can have undesired side effects. It is now possible to forbid
1466 such function calls. If function calls are forbidden, GDB will throw
1467 an error when a command (such as print expression) calls a function
1470 set print finish [on|off]
1472 This controls whether the `finish' command will display the value
1473 that is returned by the current function. When `off', the value is
1474 still entered into the value history, but it is not printed. The
1478 show print max-depth
1479 Allows deeply nested structures to be simplified when printing by
1480 replacing deeply nested parts (beyond the max-depth) with ellipses.
1481 The default max-depth is 20, but this can be set to unlimited to get
1482 the old behavior back.
1484 set print raw-values [on|off]
1485 show print raw-values
1486 By default, GDB applies the enabled pretty printers when printing a
1487 value. This allows to ignore the enabled pretty printers for a series
1488 of commands. The default is 'off'.
1490 set logging debugredirect [on|off]
1491 By default, GDB debug output will go to both the terminal and the logfile.
1492 Set if you want debug output to go only to the log file.
1494 set style title foreground COLOR
1495 set style title background COLOR
1496 set style title intensity VALUE
1497 Control the styling of titles.
1499 set style highlight foreground COLOR
1500 set style highlight background COLOR
1501 set style highlight intensity VALUE
1502 Control the styling of highlightings.
1504 maint set worker-threads
1505 maint show worker-threads
1506 Control the number of worker threads that can be used by GDB. The
1507 default is 0. "unlimited" lets GDB choose a number that is
1508 reasonable. Currently worker threads are only used when demangling
1509 the names of linker symbols.
1511 set style tui-border foreground COLOR
1512 set style tui-border background COLOR
1513 Control the styling of TUI borders.
1515 set style tui-active-border foreground COLOR
1516 set style tui-active-border background COLOR
1517 Control the styling of the active TUI border.
1519 maint set test-settings KIND
1520 maint show test-settings KIND
1521 A set of commands used by the testsuite for exercising the settings
1524 maint set tui-resize-message [on|off]
1525 maint show tui-resize-message
1526 Control whether GDB prints a message each time the terminal is
1527 resized when in TUI mode. This is primarily useful for testing the
1530 set print frame-info [short-location|location|location-and-address
1531 |source-and-location|source-line|auto]
1532 show print frame-info
1533 This controls what frame information is printed by the commands printing
1534 a frame. This setting will e.g. influence the behaviour of 'backtrace',
1535 'frame', 'stepi'. The python frame filtering also respect this setting.
1536 The 'backtrace' '-frame-info' option can override this global setting.
1538 set tui compact-source
1539 show tui compact-source
1541 Enable the "compact" display mode for the TUI source window. The
1542 compact display uses only as much space as is needed for the line
1543 numbers in the current file, and only a single space to separate the
1544 line numbers from the source.
1546 info modules [-q] [REGEXP]
1547 Return a list of Fortran modules matching REGEXP, or all modules if
1550 info module functions [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1551 Return a list of functions within all modules, grouped by module.
1552 The list of functions can be restricted with the optional regular
1553 expressions. MODULE_REGEXP matches against the module name,
1554 TYPE_REGEXP matches against the function type signature, and REGEXP
1555 matches against the function name.
1557 info module variables [-q] [-m MODULE_REGEXP] [-t TYPE_REGEXP] [REGEXP]
1558 Return a list of variables within all modules, grouped by module.
1559 The list of variables can be restricted with the optional regular
1560 expressions. MODULE_REGEXP matches against the module name,
1561 TYPE_REGEXP matches against the variable type, and REGEXP matches
1562 against the variable name.
1564 set debug remote-packet-max-chars
1565 show debug remote-packet-max-chars
1566 Controls the number of characters to output in a remote packet when using
1568 The default is 512 bytes.
1571 Lists the target connections currently in use.
1576 The "help" command uses the title style to enhance the
1577 readibility of its output by styling the classes and
1581 Similarly to "help", the "apropos" command also uses the
1582 title style for the command names. "apropos" accepts now
1583 a flag "-v" (verbose) to show the full documentation
1584 of matching commands and to use the highlight style to mark
1585 the documentation parts matching REGEXP.
1589 The GDB printf and eval commands can now print C-style and Ada-style
1590 string convenience variables without calling functions in the program.
1591 This allows to do formatted printing of strings without having
1592 a running inferior, or when debugging a core dump.
1594 info sources [-dirname | -basename] [--] [REGEXP]
1595 This command has now optional arguments to only print the files
1596 whose names match REGEXP. The arguments -dirname and -basename
1597 allow to restrict matching respectively to the dirname and basename
1601 The "show style" and its subcommands are now styling
1602 a style name in their output using its own style, to help
1603 the user visualize the different styles.
1605 set print frame-arguments
1606 The new value 'presence' indicates to only indicate the presence of
1607 arguments using ..., instead of printing argument names and values.
1609 set print raw-frame-arguments
1610 show print raw-frame-arguments
1612 These commands replace the similarly-named "set/show print raw
1613 frame-arguments" commands (now with a dash instead of a space). The
1614 old commands are now deprecated and may be removed in a future
1617 add-inferior [-no-connection]
1618 The add-inferior command now supports a "-no-connection" flag that
1619 makes the new inferior start with no target connection associated.
1620 By default, the new inferior inherits the target connection of the
1621 current inferior. See also "info connections".
1624 This command's output now includes a new "Connection" column
1625 indicating which target connection an inferior is bound to. See
1626 "info connections" above.
1628 maint test-options require-delimiter
1629 maint test-options unknown-is-error
1630 maint test-options unknown-is-operand
1631 maint show test-options-completion-result
1632 Commands used by the testsuite to validate the command options
1635 focus, winheight, +, -, >, <
1636 These commands are now case-sensitive.
1638 * New command options, command completion
1640 GDB now has a standard infrastructure to support dash-style command
1641 options ('-OPT'). One benefit is that commands that use it can
1642 easily support completion of command line arguments. Try "CMD
1643 -[TAB]" or "help CMD" to find options supported by a command. Over
1644 time, we intend to migrate most commands to this infrastructure. A
1645 number of commands got support for new command options in this
1648 ** The "print" and "compile print" commands now support a number of
1649 options that allow overriding relevant global print settings as
1650 set by "set print" subcommands:
1654 -array-indexes [on|off]
1655 -elements NUMBER|unlimited
1659 -raw-values [on|off]
1660 -repeats NUMBER|unlimited
1661 -static-members [on|off]
1666 Note that because the "print"/"compile print" commands accept
1667 arbitrary expressions which may look like options (including
1668 abbreviations), if you specify any command option, then you must
1669 use a double dash ("--") to mark the end of argument processing.
1671 ** The "backtrace" command now supports a number of options that
1672 allow overriding relevant global print settings as set by "set
1673 backtrace" and "set print" subcommands:
1675 -entry-values no|only|preferred|if-needed|both|compact|default
1676 -frame-arguments all|scalars|none
1677 -raw-frame-arguments [on|off]
1678 -frame-info auto|source-line|location|source-and-location
1679 |location-and-address|short-location
1681 -past-entry [on|off]
1683 In addition, the full/no-filters/hide qualifiers are now also
1684 exposed as command options too:
1690 ** The "frame apply", "tfaas" and "faas" commands similarly now
1691 support the following options:
1694 -past-entry [on|off]
1696 ** The new "info sources" options -dirname and -basename options
1697 are using the standard '-OPT' infrastructure.
1699 All options above can also be abbreviated. The argument of boolean
1700 (on/off) options can be 0/1 too, and also the argument is assumed
1701 "on" if omitted. This allows writing compact command invocations,
1704 (gdb) p -ra -p -o 0 -- *myptr
1706 The above is equivalent to:
1708 (gdb) print -raw-values -pretty -object off -- *myptr
1710 ** The "info types" command now supports the '-q' flag to disable
1711 printing of some header information in a similar fashion to "info
1712 variables" and "info functions".
1714 ** The "info variables", "info functions", and "whereis" commands
1715 now take a '-n' flag that excludes non-debug symbols (symbols
1716 from the symbol table, not from the debug info such as DWARF)
1719 * Completion improvements
1721 ** GDB can now complete the options of the "thread apply all" and
1722 "taas" commands, and their "-ascending" option can now be
1725 ** GDB can now complete the options of the "info threads", "info
1726 functions", "info variables", "info locals", and "info args"
1729 ** GDB can now complete the options of the "compile file" and
1730 "compile code" commands. The "compile file" command now
1731 completes on filenames.
1733 ** GDB can now complete the backtrace command's
1734 "full/no-filters/hide" qualifiers.
1736 * In settings, you can now abbreviate "unlimited".
1738 E.g., "set print elements u" is now equivalent to "set print
1739 elements unlimited".
1744 This lists all the possible completions for the rest of the line, if it
1745 were to be given as a command itself. This is intended for use by MI
1746 frontends in cases when separate CLI and MI channels cannot be used.
1748 -catch-throw, -catch-rethrow, and -catch-catch
1749 These can be used to catch C++ exceptions in a similar fashion to
1750 the CLI commands 'catch throw', 'catch rethrow', and 'catch catch'.
1752 -symbol-info-functions, -symbol-info-types, and -symbol-info-variables
1753 These commands are the MI equivalent of the CLI commands 'info
1754 functions', 'info types', and 'info variables' respectively.
1756 -symbol-info-modules, this is the MI equivalent of the CLI 'info
1759 -symbol-info-module-functions and -symbol-info-module-variables.
1760 These commands are the MI equivalent of the CLI commands 'info
1761 module functions' and 'info module variables'.
1765 ** The default version of the MI interpreter is now 3 (-i=mi3).
1767 ** The output of information about multi-location breakpoints (which is
1768 syntactically incorrect in MI 2) has changed in MI 3. This affects
1769 the following commands and events:
1773 - =breakpoint-created
1774 - =breakpoint-modified
1776 The -fix-multi-location-breakpoint-output command can be used to enable
1777 this behavior with previous MI versions.
1779 ** Backtraces and frames include a new optional field addr_flags which is
1780 given after the addr field. On AArch64 this contains PAC if the address
1781 has been masked in the frame. On all other targets the field is not
1786 The testsuite now creates the files gdb.cmd (containing the arguments
1787 used to launch GDB) and gdb.in (containing all the commands sent to
1788 GDB) in the output directory for each test script. Multiple invocations
1789 are appended with .1, .2, .3 etc.
1791 * Building GDB and GDBserver now requires GNU make >= 3.82.
1793 Using another implementation of the make program or an earlier version of
1794 GNU make to build GDB or GDBserver is not supported.
1796 * Building GDB now requires GNU readline >= 7.0.
1798 GDB now bundles GNU readline 8.0, but if you choose to use
1799 --with-system-readline, only readline >= 7.0 can be used.
1801 * The TUI SingleKey keymap is now named "SingleKey". This can be used
1802 from .inputrc to bind keys in this keymap. This feature is only
1803 available when gdb is built against GNU readline 8.0 or later.
1805 * Removed targets and native configurations
1807 GDB no longer supports debugging the Cell Broadband Engine. This includes
1808 both debugging standalone Cell/B.E. SPU applications and integrated debugging
1809 of Cell/B.E. applications that use both the PPU and SPU architectures.
1815 * Removed targets and native configurations
1817 Solaris 10 i?86-*-solaris2.10, x86_64-*-solaris2.10,
1818 sparc*-*-solaris2.10
1820 *** Changes in GDB 8.3
1822 * GDB and GDBserver now support access to additional registers on
1823 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
1826 * GDB now has experimental support for the compilation and injection of
1827 C++ source code into the inferior. This beta release does not include
1828 support for several language features, such as templates, constructors,
1831 This feature requires GCC 7.1 or higher built with libcp1.so
1834 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
1835 can be passed using the '[ADDRESS]:PORT' notation, or the regular
1836 'ADDRESS:PORT' method.
1838 * DWARF index cache: GDB can now automatically save indices of DWARF
1839 symbols on disk to speed up further loading of the same binaries.
1841 * Ada task switching is now supported on aarch64-elf targets when
1842 debugging a program using the Ravenscar Profile. For more information,
1843 see the "Tasking Support when using the Ravenscar Profile" section
1844 in the GDB user manual.
1846 * GDB in batch mode now exits with status 1 if the last command to be
1849 * The RISC-V target now supports target descriptions.
1851 * System call catchpoints now support system call aliases on FreeBSD.
1852 When the ABI of a system call changes in FreeBSD, this is
1853 implemented by leaving a compatibility system call using the old ABI
1854 at the existing number and allocating a new system call number for
1855 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
1856 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
1857 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
1858 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
1859 so that a system call catchpoint for the 'kevent' system call will
1860 catch invocations of both the 'kevent' and 'freebsd11_kevent'
1861 binaries. This ensures that 'kevent' system calls are caught for
1862 binaries using either the old or new ABIs.
1864 * Terminal styling is now available for the CLI and the TUI. GNU
1865 Source Highlight can additionally be used to provide styling of
1866 source code snippets. See the "set style" commands, below, for more
1869 * Removed support for old demangling styles arm, edg, gnu, hp and
1874 set debug compile-cplus-types
1875 show debug compile-cplus-types
1876 Control the display of debug output about type conversion in the
1877 C++ compile feature. Commands have no effect while compiling
1878 for other languages.
1882 Control whether debug output about files/functions skipping is
1885 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
1886 Apply a command to some frames.
1887 FLAG arguments allow to control what output to produce and how to handle
1888 errors raised when applying COMMAND to a frame.
1891 Apply a command to all threads (ignoring errors and empty output).
1892 Shortcut for 'thread apply all -s COMMAND'.
1895 Apply a command to all frames (ignoring errors and empty output).
1896 Shortcut for 'frame apply all -s COMMAND'.
1899 Apply a command to all frames of all threads (ignoring errors and empty
1901 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
1903 maint set dwarf unwinders (on|off)
1904 maint show dwarf unwinders
1905 Control whether DWARF unwinders can be used.
1908 Display a list of open files for a process.
1912 Changes to the "frame", "select-frame", and "info frame" CLI commands.
1913 These commands all now take a frame specification which
1914 is either a frame level, or one of the keywords 'level', 'address',
1915 'function', or 'view' followed by a parameter. Selecting a frame by
1916 address, or viewing a frame outside the current backtrace now
1917 requires the use of a keyword. Selecting a frame by level is
1918 unchanged. The MI comment "-stack-select-frame" is unchanged.
1920 target remote FILENAME
1921 target extended-remote FILENAME
1922 If FILENAME is a Unix domain socket, GDB will attempt to connect
1923 to this socket instead of opening FILENAME as a character device.
1925 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1926 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1927 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1928 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
1929 These commands can now print only the searched entities
1930 matching the provided regexp(s), giving a condition
1931 on the entity names or entity types. The flag -q disables
1932 printing headers or informations messages.
1938 These commands now determine the syntax for the shown entities
1939 according to the language chosen by `set language'. In particular,
1940 `set language auto' means to automatically choose the language of
1943 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
1944 The 'thread apply' command accepts new FLAG arguments.
1945 FLAG arguments allow to control what output to produce and how to handle
1946 errors raised when applying COMMAND to a thread.
1948 set tui tab-width NCHARS
1949 show tui tab-width NCHARS
1950 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
1952 set style enabled [on|off]
1954 Enable or disable terminal styling. Styling is enabled by default
1955 on most hosts, but disabled by default when in batch mode.
1957 set style sources [on|off]
1959 Enable or disable source code styling. Source code styling is
1960 enabled by default, but only takes effect if styling in general is
1961 enabled, and if GDB was linked with GNU Source Highlight.
1963 set style filename foreground COLOR
1964 set style filename background COLOR
1965 set style filename intensity VALUE
1966 Control the styling of file names.
1968 set style function foreground COLOR
1969 set style function background COLOR
1970 set style function intensity VALUE
1971 Control the styling of function names.
1973 set style variable foreground COLOR
1974 set style variable background COLOR
1975 set style variable intensity VALUE
1976 Control the styling of variable names.
1978 set style address foreground COLOR
1979 set style address background COLOR
1980 set style address intensity VALUE
1981 Control the styling of addresses.
1985 ** The '-data-disassemble' MI command now accepts an '-a' option to
1986 disassemble the whole function surrounding the given program
1987 counter value or function name. Support for this feature can be
1988 verified by using the "-list-features" command, which should
1989 contain "data-disassemble-a-option".
1991 ** Command responses and notifications that include a frame now include
1992 the frame's architecture in a new "arch" attribute.
1994 * New native configurations
1996 GNU/Linux/RISC-V riscv*-*-linux*
1997 FreeBSD/riscv riscv*-*-freebsd*
2001 GNU/Linux/RISC-V riscv*-*-linux*
2002 CSKY ELF csky*-*-elf
2003 CSKY GNU/LINUX csky*-*-linux
2004 FreeBSD/riscv riscv*-*-freebsd*
2006 GNU/Linux/OpenRISC or1k*-*-linux*
2010 GDB no longer supports native debugging on versions of MS-Windows
2015 ** GDB no longer supports Python versions less than 2.6.
2017 ** The gdb.Inferior type has a new 'progspace' property, which is the program
2018 space associated to that inferior.
2020 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
2021 of objfiles associated to that program space.
2023 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
2024 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
2027 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
2028 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
2029 correct and did not work properly.
2031 ** The gdb.Value type has a new constructor, which is used to construct a
2032 gdb.Value from a Python buffer object and a gdb.Type.
2038 Enable or disable the undefined behavior sanitizer. This is
2039 disabled by default, but passing --enable-ubsan=yes or
2040 --enable-ubsan=auto to configure will enable it. Enabling this can
2041 cause a performance penalty. The undefined behavior sanitizer was
2042 first introduced in GCC 4.9.
2044 *** Changes in GDB 8.2
2046 * The 'set disassembler-options' command now supports specifying options
2047 for the MIPS target.
2049 * The 'symbol-file' command now accepts an '-o' option to add a relative
2050 offset to all sections.
2052 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
2053 a relative offset to all sections, but it allows to override the load
2054 address of individual sections using '-s'.
2056 * The 'add-symbol-file' command no longer requires the second argument
2057 (address of the text section).
2059 * The endianness used with the 'set endian auto' mode in the absence of
2060 an executable selected for debugging is now the last endianness chosen
2061 either by one of the 'set endian big' and 'set endian little' commands
2062 or by inferring from the last executable used, rather than the startup
2065 * The pager now allows a "c" response, meaning to disable the pager
2066 for the rest of the current command.
2068 * The commands 'info variables/functions/types' now show the source line
2069 numbers of symbol definitions when available.
2071 * 'info proc' now works on running processes on FreeBSD systems and core
2072 files created on FreeBSD systems.
2074 * C expressions can now use _Alignof, and C++ expressions can now use
2077 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
2078 the vector length while the process is running.
2084 Control display of debugging info regarding the FreeBSD native target.
2086 set|show varsize-limit
2087 This new setting allows the user to control the maximum size of Ada
2088 objects being printed when those objects have a variable type,
2089 instead of that maximum size being hardcoded to 65536 bytes.
2091 set|show record btrace cpu
2092 Controls the processor to be used for enabling errata workarounds for
2093 branch trace decode.
2095 maint check libthread-db
2096 Run integrity checks on the current inferior's thread debugging
2099 maint set check-libthread-db (on|off)
2100 maint show check-libthread-db
2101 Control whether to run integrity checks on inferior specific thread
2102 debugging libraries as they are loaded. The default is not to
2103 perform such checks.
2107 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
2109 ** The commands attached to a breakpoint can be set by assigning to
2110 the breakpoint's "commands" field.
2112 ** gdb.execute can now execute multi-line gdb commands.
2114 ** The new functions gdb.convenience_variable and
2115 gdb.set_convenience_variable can be used to get and set the value
2116 of convenience variables.
2118 ** A gdb.Parameter will no longer print the "set" help text on an
2119 ordinary "set"; instead by default a "set" will be silent unless
2120 the get_set_string method returns a non-empty string.
2124 RiscV ELF riscv*-*-elf
2126 * Removed targets and native configurations
2128 m88k running OpenBSD m88*-*-openbsd*
2129 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
2130 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
2131 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
2133 * Aarch64/Linux hardware watchpoints improvements
2135 Hardware watchpoints on unaligned addresses are now properly
2136 supported when running Linux kernel 4.10 or higher: read and access
2137 watchpoints are no longer spuriously missed, and all watchpoints
2138 lengths between 1 and 8 bytes are supported. On older kernels,
2139 watchpoints set on unaligned addresses are no longer missed, with
2140 the tradeoff that there is a possibility of false hits being
2145 --enable-codesign=CERT
2146 This can be used to invoke "codesign -s CERT" after building gdb.
2147 This option is useful on macOS, where code signing is required for
2148 gdb to work properly.
2150 --disable-gdbcli has been removed
2151 This is now silently accepted, but does nothing.
2153 *** Changes in GDB 8.1
2155 * GDB now supports dynamically creating arbitrary register groups specified
2156 in XML target descriptions. This allows for finer grain grouping of
2157 registers on systems with a large amount of registers.
2159 * The 'ptype' command now accepts a '/o' flag, which prints the
2160 offsets and sizes of fields in a struct, like the pahole(1) tool.
2162 * New "--readnever" command line option instructs GDB to not read each
2163 symbol file's symbolic debug information. This makes startup faster
2164 but at the expense of not being able to perform symbolic debugging.
2165 This option is intended for use cases where symbolic debugging will
2166 not be used, e.g., when you only need to dump the debuggee's core.
2168 * GDB now uses the GNU MPFR library, if available, to emulate target
2169 floating-point arithmetic during expression evaluation when the target
2170 uses different floating-point formats than the host. At least version
2171 3.1 of GNU MPFR is required.
2173 * GDB now supports access to the guarded-storage-control registers and the
2174 software-based guarded-storage broadcast control registers on IBM z14.
2176 * On Unix systems, GDB now supports transmitting environment variables
2177 that are to be set or unset to GDBserver. These variables will
2178 affect the environment to be passed to the remote inferior.
2180 To inform GDB of environment variables that are to be transmitted to
2181 GDBserver, use the "set environment" command. Only user set
2182 environment variables are sent to GDBserver.
2184 To inform GDB of environment variables that are to be unset before
2185 the remote inferior is started by the GDBserver, use the "unset
2186 environment" command.
2188 * Completion improvements
2190 ** GDB can now complete function parameters in linespecs and
2191 explicit locations without quoting. When setting breakpoints,
2192 quoting around functions names to help with TAB-completion is
2193 generally no longer necessary. For example, this now completes
2196 (gdb) b function(in[TAB]
2197 (gdb) b function(int)
2199 Related, GDB is no longer confused with completing functions in
2200 C++ anonymous namespaces:
2203 (gdb) b (anonymous namespace)::[TAB][TAB]
2204 (anonymous namespace)::a_function()
2205 (anonymous namespace)::b_function()
2207 ** GDB now has much improved linespec and explicit locations TAB
2208 completion support, that better understands what you're
2209 completing and offers better suggestions. For example, GDB no
2210 longer offers data symbols as possible completions when you're
2211 setting a breakpoint.
2213 ** GDB now TAB-completes label symbol names.
2215 ** The "complete" command now mimics TAB completion accurately.
2217 * New command line options (gcore)
2220 Dump all memory mappings.
2222 * Breakpoints on C++ functions are now set on all scopes by default
2224 By default, breakpoints on functions/methods are now interpreted as
2225 specifying all functions with the given name ignoring missing
2226 leading scopes (namespaces and classes).
2228 For example, assuming a C++ program with symbols named:
2233 both commands "break func()" and "break B::func()" set a breakpoint
2236 You can use the new flag "-qualified" to override this. This makes
2237 GDB interpret the specified function name as a complete
2238 fully-qualified name instead. For example, using the same C++
2239 program, the "break -q B::func" command sets a breakpoint on
2240 "B::func", only. A parameter has been added to the Python
2241 gdb.Breakpoint constructor to achieve the same result when creating
2242 a breakpoint from Python.
2244 * Breakpoints on functions marked with C++ ABI tags
2246 GDB can now set breakpoints on functions marked with C++ ABI tags
2247 (e.g., [abi:cxx11]). See here for a description of ABI tags:
2248 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
2250 Functions with a C++11 abi tag are demangled/displayed like this:
2252 function[abi:cxx11](int)
2255 You can now set a breakpoint on such functions simply as if they had
2258 (gdb) b function(int)
2260 Or if you need to disambiguate between tags, like:
2262 (gdb) b function[abi:other_tag](int)
2264 Tab completion was adjusted accordingly as well.
2268 ** New events gdb.new_inferior, gdb.inferior_deleted, and
2269 gdb.new_thread are emitted. See the manual for further
2270 description of these.
2272 ** A new function, "gdb.rbreak" has been added to the Python API.
2273 This function allows the setting of a large number of breakpoints
2274 via a regex pattern in Python. See the manual for further details.
2276 ** Python breakpoints can now accept explicit locations. See the
2277 manual for a further description of this feature.
2280 * New features in the GDB remote stub, GDBserver
2282 ** GDBserver is now able to start inferior processes with a
2283 specified initial working directory.
2285 The user can set the desired working directory to be used from
2286 GDB using the new "set cwd" command.
2288 ** New "--selftest" command line option runs some GDBserver self
2289 tests. These self tests are disabled in releases.
2291 ** On Unix systems, GDBserver now does globbing expansion and variable
2292 substitution in inferior command line arguments.
2294 This is done by starting inferiors using a shell, like GDB does.
2295 See "set startup-with-shell" in the user manual for how to disable
2296 this from GDB when using "target extended-remote". When using
2297 "target remote", you can disable the startup with shell by using the
2298 new "--no-startup-with-shell" GDBserver command line option.
2300 ** On Unix systems, GDBserver now supports receiving environment
2301 variables that are to be set or unset from GDB. These variables
2302 will affect the environment to be passed to the inferior.
2304 * When catching an Ada exception raised with a message, GDB now prints
2305 the message in the catchpoint hit notification. In GDB/MI mode, that
2306 information is provided as an extra field named "exception-message"
2307 in the *stopped notification.
2309 * Trait objects can now be inspected When debugging Rust code. This
2310 requires compiler support which will appear in Rust 1.24.
2312 * New remote packets
2314 QEnvironmentHexEncoded
2315 Inform GDBserver of an environment variable that is to be passed to
2316 the inferior when starting it.
2319 Inform GDBserver of an environment variable that is to be unset
2320 before starting the remote inferior.
2323 Inform GDBserver that the environment should be reset (i.e.,
2324 user-set environment variables should be unset).
2327 Indicates whether the inferior must be started with a shell or not.
2330 Tell GDBserver that the inferior to be started should use a specific
2333 * The "maintenance print c-tdesc" command now takes an optional
2334 argument which is the file name of XML target description.
2336 * The "maintenance selftest" command now takes an optional argument to
2337 filter the tests to be run.
2339 * The "enable", and "disable" commands now accept a range of
2340 breakpoint locations, e.g. "enable 1.3-5".
2345 Set and show the current working directory for the inferior.
2347 set|show compile-gcc
2348 Set and show compilation command used for compiling and injecting code
2349 with the 'compile' commands.
2351 set debug separate-debug-file
2352 show debug separate-debug-file
2353 Control the display of debug output about separate debug file search.
2355 set dump-excluded-mappings
2356 show dump-excluded-mappings
2357 Control whether mappings marked with the VM_DONTDUMP flag should be
2358 dumped when generating a core file.
2360 maint info selftests
2361 List the registered selftests.
2364 Start the debugged program stopping at the first instruction.
2367 Control display of debugging messages related to OpenRISC targets.
2369 set|show print type nested-type-limit
2370 Set and show the limit of nesting level for nested types that the
2371 type printer will show.
2373 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
2376 * Safer/improved support for debugging with no debug info
2378 GDB no longer assumes functions with no debug information return
2381 This means that GDB now refuses to call such functions unless you
2382 tell it the function's type, by either casting the call to the
2383 declared return type, or by casting the function to a function
2384 pointer of the right type, and calling that:
2386 (gdb) p getenv ("PATH")
2387 'getenv' has unknown return type; cast the call to its declared return type
2388 (gdb) p (char *) getenv ("PATH")
2389 $1 = 0x7fffffffe "/usr/local/bin:/"...
2390 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
2391 $2 = 0x7fffffffe "/usr/local/bin:/"...
2393 Similarly, GDB no longer assumes that global variables with no debug
2394 info have type 'int', and refuses to print the variable's value
2395 unless you tell it the variable's type:
2398 'var' has unknown type; cast it to its declared type
2402 * New native configurations
2404 FreeBSD/aarch64 aarch64*-*-freebsd*
2405 FreeBSD/arm arm*-*-freebsd*
2409 FreeBSD/aarch64 aarch64*-*-freebsd*
2410 FreeBSD/arm arm*-*-freebsd*
2411 OpenRISC ELF or1k*-*-elf
2413 * Removed targets and native configurations
2415 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
2417 *** Changes in GDB 8.0
2419 * GDB now supports access to the PKU register on GNU/Linux. The register is
2420 added by the Memory Protection Keys for Userspace feature which will be
2421 available in future Intel CPUs.
2423 * GDB now supports C++11 rvalue references.
2427 ** New functions to start, stop and access a running btrace recording.
2428 ** Rvalue references are now supported in gdb.Type.
2430 * GDB now supports recording and replaying rdrand and rdseed Intel 64
2433 * Building GDB and GDBserver now requires a C++11 compiler.
2435 For example, GCC 4.8 or later.
2437 It is no longer possible to build GDB or GDBserver with a C
2438 compiler. The --disable-build-with-cxx configure option has been
2441 * Building GDB and GDBserver now requires GNU make >= 3.81.
2443 It is no longer supported to build GDB or GDBserver with another
2444 implementation of the make program or an earlier version of GNU make.
2446 * Native debugging on MS-Windows supports command-line redirection
2448 Command-line arguments used for starting programs on MS-Windows can
2449 now include redirection symbols supported by native Windows shells,
2450 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
2451 as "run", "start", and "set args", as well as the corresponding MI
2454 * Support for thread names on MS-Windows.
2456 GDB now catches and handles the special exception that programs
2457 running on MS-Windows use to assign names to threads in the
2460 * Support for Java programs compiled with gcj has been removed.
2462 * User commands now accept an unlimited number of arguments.
2463 Previously, only up to 10 was accepted.
2465 * The "eval" command now expands user-defined command arguments.
2467 This makes it easier to process a variable number of arguments:
2472 eval "print $arg%d", $i
2477 * Target descriptions can now describe registers for sparc32 and sparc64.
2479 * GDB now supports DWARF version 5 (debug information format).
2480 Its .debug_names index is not yet supported.
2482 * New native configurations
2484 FreeBSD/mips mips*-*-freebsd
2488 Synopsys ARC arc*-*-elf32
2489 FreeBSD/mips mips*-*-freebsd
2491 * Removed targets and native configurations
2493 Alpha running FreeBSD alpha*-*-freebsd*
2494 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
2499 Erases all the flash memory regions reported by the target.
2501 maint print arc arc-instruction address
2502 Print internal disassembler information about instruction at a given address.
2506 set disassembler-options
2507 show disassembler-options
2508 Controls the passing of target specific information to the disassembler.
2509 If it is necessary to specify more than one disassembler option then
2510 multiple options can be placed together into a comma separated list.
2511 The default value is the empty string. Currently, the only supported
2512 targets are ARM, PowerPC and S/390.
2517 Erases all the flash memory regions reported by the target. This is
2518 equivalent to the CLI command flash-erase.
2520 -file-list-shared-libraries
2521 List the shared libraries in the program. This is
2522 equivalent to the CLI command "info shared".
2525 Catchpoints stopping the program when Ada exceptions are
2526 handled. This is equivalent to the CLI command "catch handlers".
2528 *** Changes in GDB 7.12
2530 * GDB and GDBserver now build with a C++ compiler by default.
2532 The --enable-build-with-cxx configure option is now enabled by
2533 default. One must now explicitly configure with
2534 --disable-build-with-cxx in order to build with a C compiler. This
2535 option will be removed in a future release.
2537 * GDBserver now supports recording btrace without maintaining an active
2540 * GDB now supports a negative repeat count in the 'x' command to examine
2541 memory backward from the given address. For example:
2544 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
2545 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
2546 (gdb) x/-5i 0x0000000000400580
2547 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
2548 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
2549 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
2550 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
2551 0x40057b <main(int, char**)+25>:
2552 callq 0x400536 <Func1(int, char const*)>
2554 * Fortran: Support structures with fields of dynamic types and
2555 arrays of dynamic types.
2557 * The symbol dumping maintenance commands have new syntax.
2558 maint print symbols [-pc address] [--] [filename]
2559 maint print symbols [-objfile objfile] [-source source] [--] [filename]
2560 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
2561 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
2562 maint print msymbols [-objfile objfile] [--] [filename]
2564 * GDB now supports multibit bitfields and enums in target register
2567 * New Python-based convenience function $_as_string(val), which returns
2568 the textual representation of a value. This function is especially
2569 useful to obtain the text label of an enum value.
2571 * Intel MPX bound violation handling.
2573 Segmentation faults caused by a Intel MPX boundary violation
2574 now display the kind of violation (upper or lower), the memory
2575 address accessed and the memory bounds, along with the usual
2576 signal received and code location.
2580 Program received signal SIGSEGV, Segmentation fault
2581 Upper bound violation while accessing address 0x7fffffffc3b3
2582 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
2583 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
2585 * Rust language support.
2586 GDB now supports debugging programs written in the Rust programming
2587 language. See https://www.rust-lang.org/ for more information about
2590 * Support for running interpreters on specified input/output devices
2592 GDB now supports a new mechanism that allows frontends to provide
2593 fully featured GDB console views, as a better alternative to
2594 building such views on top of the "-interpreter-exec console"
2595 command. See the new "new-ui" command below. With that command,
2596 frontends can now start GDB in the traditional command-line mode
2597 running in an embedded terminal emulator widget, and create a
2598 separate MI interpreter running on a specified i/o device. In this
2599 way, GDB handles line editing, history, tab completion, etc. in the
2600 console all by itself, and the GUI uses the separate MI interpreter
2601 for its own control and synchronization, invisible to the command
2604 * The "catch syscall" command catches groups of related syscalls.
2606 The "catch syscall" command now supports catching a group of related
2607 syscalls using the 'group:' or 'g:' prefix.
2612 skip -gfile file-glob-pattern
2613 skip -function function
2614 skip -rfunction regular-expression
2615 A generalized form of the skip command, with new support for
2616 glob-style file names and regular expressions for function names.
2617 Additionally, a file spec and a function spec may now be combined.
2619 maint info line-table REGEXP
2620 Display the contents of GDB's internal line table data structure.
2623 Run any GDB unit tests that were compiled in.
2626 Start a new user interface instance running INTERP as interpreter,
2627 using the TTY file for input/output.
2631 ** gdb.Breakpoint objects have a new attribute "pending", which
2632 indicates whether the breakpoint is pending.
2633 ** Three new breakpoint-related events have been added:
2634 gdb.breakpoint_created, gdb.breakpoint_modified, and
2635 gdb.breakpoint_deleted.
2637 signal-event EVENTID
2638 Signal ("set") the given MS-Windows event object. This is used in
2639 conjunction with the Windows JIT debugging (AeDebug) support, where
2640 the OS suspends a crashing process until a debugger can attach to
2641 it. Resuming the crashing process, in order to debug it, is done by
2642 signalling an event.
2644 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
2645 was added in GDBserver, including JIT compiling fast tracepoint's
2646 conditional expression bytecode into native code.
2648 * Support for various remote target protocols and ROM monitors has
2651 target m32rsdi Remote M32R debugging over SDI
2652 target mips MIPS remote debugging protocol
2653 target pmon PMON ROM monitor
2654 target ddb NEC's DDB variant of PMON for Vr4300
2655 target rockhopper NEC RockHopper variant of PMON
2656 target lsi LSI variant of PMO
2658 * Support for tracepoints and fast tracepoints on powerpc-linux,
2659 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
2660 including JIT compiling fast tracepoint's conditional expression
2661 bytecode into native code.
2663 * MI async record =record-started now includes the method and format used for
2664 recording. For example:
2666 =record-started,thread-group="i1",method="btrace",format="bts"
2668 * MI async record =thread-selected now includes the frame field. For example:
2670 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
2674 Andes NDS32 nds32*-*-elf
2676 *** Changes in GDB 7.11
2678 * GDB now supports debugging kernel-based threads on FreeBSD.
2680 * Per-inferior thread numbers
2682 Thread numbers are now per inferior instead of global. If you're
2683 debugging multiple inferiors, GDB displays thread IDs using a
2684 qualified INF_NUM.THR_NUM form. For example:
2688 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
2689 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
2690 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
2691 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
2693 As consequence, thread numbers as visible in the $_thread
2694 convenience variable and in Python's InferiorThread.num attribute
2695 are no longer unique between inferiors.
2697 GDB now maintains a second thread ID per thread, referred to as the
2698 global thread ID, which is the new equivalent of thread numbers in
2699 previous releases. See also $_gthread below.
2701 For backwards compatibility, MI's thread IDs always refer to global
2704 * Commands that accept thread IDs now accept the qualified
2705 INF_NUM.THR_NUM form as well. For example:
2708 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
2711 * In commands that accept a list of thread IDs, you can now refer to
2712 all threads of an inferior using a star wildcard. GDB accepts
2713 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
2714 refer to all threads of the current inferior. For example, "info
2717 * You can use "info threads -gid" to display the global thread ID of
2720 * The new convenience variable $_gthread holds the global number of
2723 * The new convenience variable $_inferior holds the number of the
2726 * GDB now displays the ID and name of the thread that hit a breakpoint
2727 or received a signal, if your program is multi-threaded. For
2730 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
2731 Thread 1 "main" received signal SIGINT, Interrupt.
2733 * Record btrace now supports non-stop mode.
2735 * Support for tracepoints on aarch64-linux was added in GDBserver.
2737 * The 'record instruction-history' command now indicates speculative execution
2738 when using the Intel Processor Trace recording format.
2740 * GDB now allows users to specify explicit locations, bypassing
2741 the linespec parser. This feature is also available to GDB/MI
2744 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
2745 GDB now is able to debug both AArch64 applications and ARM applications
2748 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
2749 including JIT compiling fast tracepoint's conditional expression bytecode
2752 * GDB now supports displaced stepping on AArch64 GNU/Linux.
2754 * "info threads", "info inferiors", "info display", "info checkpoints"
2755 and "maint info program-spaces" now list the corresponding items in
2756 ascending ID order, for consistency with all other "info" commands.
2758 * In Ada, the overloads selection menu has been enhanced to display the
2759 parameter types and the return types for the matching overloaded subprograms.
2763 maint set target-non-stop (on|off|auto)
2764 maint show target-non-stop
2765 Control whether GDB targets always operate in non-stop mode even if
2766 "set non-stop" is "off". The default is "auto", meaning non-stop
2767 mode is enabled if supported by the target.
2769 maint set bfd-sharing
2770 maint show bfd-sharing
2771 Control the reuse of bfd objects.
2774 show debug bfd-cache
2775 Control display of debugging info regarding bfd caching.
2779 Control display of debugging info regarding FreeBSD threads.
2781 set remote multiprocess-extensions-packet
2782 show remote multiprocess-extensions-packet
2783 Set/show the use of the remote protocol multiprocess extensions.
2785 set remote thread-events
2786 show remote thread-events
2787 Set/show the use of thread create/exit events.
2789 set ada print-signatures on|off
2790 show ada print-signatures"
2791 Control whether parameter types and return types are displayed in overloads
2792 selection menus. It is activated (@code{on}) by default.
2796 Controls the maximum size of memory, in bytes, that GDB will
2797 allocate for value contents. Prevents incorrect programs from
2798 causing GDB to allocate overly large buffers. Default is 64k.
2800 * The "disassemble" command accepts a new modifier: /s.
2801 It prints mixed source+disassembly like /m with two differences:
2802 - disassembled instructions are now printed in program order, and
2803 - and source for all relevant files is now printed.
2804 The "/m" option is now considered deprecated: its "source-centric"
2805 output hasn't proved useful in practice.
2807 * The "record instruction-history" command accepts a new modifier: /s.
2808 It behaves exactly like /m and prints mixed source+disassembly.
2810 * The "set scheduler-locking" command supports a new mode "replay".
2811 It behaves like "off" in record mode and like "on" in replay mode.
2813 * Support for various ROM monitors has been removed:
2815 target dbug dBUG ROM monitor for Motorola ColdFire
2816 target picobug Motorola picobug monitor
2817 target dink32 DINK32 ROM monitor for PowerPC
2818 target m32r Renesas M32R/D ROM monitor
2819 target mon2000 mon2000 ROM monitor
2820 target ppcbug PPCBUG ROM monitor for PowerPC
2822 * Support for reading/writing memory and extracting values on architectures
2823 whose memory is addressable in units of any integral multiple of 8 bits.
2826 Allows to break when an Ada exception is handled.
2828 * New remote packets
2831 Indicates that an exec system call was executed.
2833 exec-events feature in qSupported
2834 The qSupported packet allows GDB to request support for exec
2835 events using the new 'gdbfeature' exec-event, and the qSupported
2836 response can contain the corresponding 'stubfeature'. Set and
2837 show commands can be used to display whether these features are enabled.
2840 Equivalent to interrupting with the ^C character, but works in
2843 thread created stop reason (T05 create:...)
2844 Indicates that the thread was just created and is stopped at entry.
2846 thread exit stop reply (w exitcode;tid)
2847 Indicates that the thread has terminated.
2850 Enables/disables thread create and exit event reporting. For
2851 example, this is used in non-stop mode when GDB stops a set of
2852 threads and synchronously waits for the their corresponding stop
2853 replies. Without exit events, if one of the threads exits, GDB
2854 would hang forever not knowing that it should no longer expect a
2855 stop for that same thread.
2858 Indicates that there are no resumed threads left in the target (all
2859 threads are stopped). The remote stub reports support for this stop
2860 reply to GDB's qSupported query.
2863 Enables/disables catching syscalls from the inferior process.
2864 The remote stub reports support for this packet to GDB's qSupported query.
2866 syscall_entry stop reason
2867 Indicates that a syscall was just called.
2869 syscall_return stop reason
2870 Indicates that a syscall just returned.
2872 * Extended-remote exec events
2874 ** GDB now has support for exec events on extended-remote Linux targets.
2875 For such targets with Linux kernels 2.5.46 and later, this enables
2876 follow-exec-mode and exec catchpoints.
2878 set remote exec-event-feature-packet
2879 show remote exec-event-feature-packet
2880 Set/show the use of the remote exec event feature.
2882 * Thread names in remote protocol
2884 The reply to qXfer:threads:read may now include a name attribute for each
2887 * Target remote mode fork and exec events
2889 ** GDB now has support for fork and exec events on target remote mode
2890 Linux targets. For such targets with Linux kernels 2.5.46 and later,
2891 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
2892 fork and exec catchpoints.
2894 * Remote syscall events
2896 ** GDB now has support for catch syscall on remote Linux targets,
2897 currently enabled on x86/x86_64 architectures.
2899 set remote catch-syscall-packet
2900 show remote catch-syscall-packet
2901 Set/show the use of the remote catch syscall feature.
2905 ** The -var-set-format command now accepts the zero-hexadecimal
2906 format. It outputs data in hexadecimal format with zero-padding on the
2911 ** gdb.InferiorThread objects have a new attribute "global_num",
2912 which refers to the thread's global thread ID. The existing
2913 "num" attribute now refers to the thread's per-inferior number.
2914 See "Per-inferior thread numbers" above.
2915 ** gdb.InferiorThread objects have a new attribute "inferior", which
2916 is the Inferior object the thread belongs to.
2918 *** Changes in GDB 7.10
2920 * Support for process record-replay and reverse debugging on aarch64*-linux*
2921 targets has been added. GDB now supports recording of A64 instruction set
2922 including advance SIMD instructions.
2924 * Support for Sun's version of the "stabs" debug file format has been removed.
2926 * GDB now honors the content of the file /proc/PID/coredump_filter
2927 (PID is the process ID) on GNU/Linux systems. This file can be used
2928 to specify the types of memory mappings that will be included in a
2929 corefile. For more information, please refer to the manual page of
2930 "core(5)". GDB also has a new command: "set use-coredump-filter
2931 on|off". It allows to set whether GDB will read the content of the
2932 /proc/PID/coredump_filter file when generating a corefile.
2934 * The "info os" command on GNU/Linux can now display information on
2936 "info os cpus" Listing of all cpus/cores on the system
2938 * GDB has two new commands: "set serial parity odd|even|none" and
2939 "show serial parity". These allows to set or show parity for the
2942 * The "info source" command now displays the producer string if it was
2943 present in the debug info. This typically includes the compiler version
2944 and may include things like its command line arguments.
2946 * The "info dll", an alias of the "info sharedlibrary" command,
2947 is now available on all platforms.
2949 * Directory names supplied to the "set sysroot" commands may be
2950 prefixed with "target:" to tell GDB to access shared libraries from
2951 the target system, be it local or remote. This replaces the prefix
2952 "remote:". The default sysroot has been changed from "" to
2953 "target:". "remote:" is automatically converted to "target:" for
2954 backward compatibility.
2956 * The system root specified by "set sysroot" will be prepended to the
2957 filename of the main executable (if reported to GDB as absolute by
2958 the operating system) when starting processes remotely, and when
2959 attaching to already-running local or remote processes.
2961 * GDB now supports automatic location and retrieval of executable
2962 files from remote targets. Remote debugging can now be initiated
2963 using only a "target remote" or "target extended-remote" command
2964 (no "set sysroot" or "file" commands are required). See "New remote
2967 * The "dump" command now supports verilog hex format.
2969 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
2971 * On GNU/Linux, GDB and gdbserver are now able to access executable
2972 and shared library files without a "set sysroot" command when
2973 attaching to processes running in different mount namespaces from
2974 the debugger. This makes it possible to attach to processes in
2975 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
2976 See "New remote packets" below.
2978 * The "tui reg" command now provides completion for all of the
2979 available register groups, including target specific groups.
2981 * The HISTSIZE environment variable is no longer read when determining
2982 the size of GDB's command history. GDB now instead reads the dedicated
2983 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
2984 disables truncation of command history. Non-numeric values of GDBHISTSIZE
2989 ** Memory ports can now be unbuffered.
2993 ** gdb.Objfile objects have a new attribute "username",
2994 which is the name of the objfile as specified by the user,
2995 without, for example, resolving symlinks.
2996 ** You can now write frame unwinders in Python.
2997 ** gdb.Type objects have a new method "optimized_out",
2998 returning optimized out gdb.Value instance of this type.
2999 ** gdb.Value objects have new methods "reference_value" and
3000 "const_value" which return a reference to the value and a
3001 "const" version of the value respectively.
3005 maint print symbol-cache
3006 Print the contents of the symbol cache.
3008 maint print symbol-cache-statistics
3009 Print statistics of symbol cache usage.
3011 maint flush-symbol-cache
3012 Flush the contents of the symbol cache.
3016 Start branch trace recording using Branch Trace Store (BTS) format.
3019 Evaluate expression by using the compiler and print result.
3023 Explicit commands for enabling and disabling tui mode.
3026 set mpx bound on i386 and amd64
3027 Support for bound table investigation on Intel MPX enabled applications.
3031 Start branch trace recording using Intel Processor Trace format.
3034 Print information about branch tracing internals.
3036 maint btrace packet-history
3037 Print the raw branch tracing data.
3039 maint btrace clear-packet-history
3040 Discard the stored raw branch tracing data.
3043 Discard all branch tracing data. It will be fetched and processed
3044 anew by the next "record" command.
3049 Renamed from "set debug dwarf2-die".
3050 show debug dwarf-die
3051 Renamed from "show debug dwarf2-die".
3053 set debug dwarf-read
3054 Renamed from "set debug dwarf2-read".
3055 show debug dwarf-read
3056 Renamed from "show debug dwarf2-read".
3058 maint set dwarf always-disassemble
3059 Renamed from "maint set dwarf2 always-disassemble".
3060 maint show dwarf always-disassemble
3061 Renamed from "maint show dwarf2 always-disassemble".
3063 maint set dwarf max-cache-age
3064 Renamed from "maint set dwarf2 max-cache-age".
3065 maint show dwarf max-cache-age
3066 Renamed from "maint show dwarf2 max-cache-age".
3068 set debug dwarf-line
3069 show debug dwarf-line
3070 Control display of debugging info regarding DWARF line processing.
3073 show max-completions
3074 Set the maximum number of candidates to be considered during
3075 completion. The default value is 200. This limit allows GDB
3076 to avoid generating large completion lists, the computation of
3077 which can cause the debugger to become temporarily unresponsive.
3079 set history remove-duplicates
3080 show history remove-duplicates
3081 Control the removal of duplicate history entries.
3083 maint set symbol-cache-size
3084 maint show symbol-cache-size
3085 Control the size of the symbol cache.
3087 set|show record btrace bts buffer-size
3088 Set and show the size of the ring buffer used for branch tracing in
3090 The obtained size may differ from the requested size. Use "info
3091 record" to see the obtained buffer size.
3093 set debug linux-namespaces
3094 show debug linux-namespaces
3095 Control display of debugging info regarding Linux namespaces.
3097 set|show record btrace pt buffer-size
3098 Set and show the size of the ring buffer used for branch tracing in
3099 Intel Processor Trace format.
3100 The obtained size may differ from the requested size. Use "info
3101 record" to see the obtained buffer size.
3103 maint set|show btrace pt skip-pad
3104 Set and show whether PAD packets are skipped when computing the
3107 * The command 'thread apply all' can now support new option '-ascending'
3108 to call its specified command for all threads in ascending order.
3110 * Python/Guile scripting
3112 ** GDB now supports auto-loading of Python/Guile scripts contained in the
3113 special section named `.debug_gdb_scripts'.
3115 * New remote packets
3117 qXfer:btrace-conf:read
3118 Return the branch trace configuration for the current thread.
3120 Qbtrace-conf:bts:size
3121 Set the requested ring buffer size for branch tracing in BTS format.
3124 Enable Intel Processor Trace-based branch tracing for the current
3125 process. The remote stub reports support for this packet to GDB's
3128 Qbtrace-conf:pt:size
3129 Set the requested ring buffer size for branch tracing in Intel Processor
3133 Indicates a memory breakpoint instruction was executed, irrespective
3134 of whether it was GDB that planted the breakpoint or the breakpoint
3135 is hardcoded in the program. This is required for correct non-stop
3139 Indicates the target stopped for a hardware breakpoint. This is
3140 required for correct non-stop mode operation.
3143 Return information about files on the remote system.
3145 qXfer:exec-file:read
3146 Return the full absolute name of the file that was executed to
3147 create a process running on the remote system.
3150 Select the filesystem on which vFile: operations with filename
3151 arguments will operate. This is required for GDB to be able to
3152 access files on remote targets where the remote stub does not
3153 share a common filesystem with the inferior(s).
3156 Indicates that a fork system call was executed.
3159 Indicates that a vfork system call was executed.
3161 vforkdone stop reason
3162 Indicates that a vfork child of the specified process has executed
3163 an exec or exit, allowing the vfork parent to resume execution.
3165 fork-events and vfork-events features in qSupported
3166 The qSupported packet allows GDB to request support for fork and
3167 vfork events using new 'gdbfeatures' fork-events and vfork-events,
3168 and the qSupported response can contain the corresponding
3169 'stubfeatures'. Set and show commands can be used to display
3170 whether these features are enabled.
3172 * Extended-remote fork events
3174 ** GDB now has support for fork events on extended-remote Linux
3175 targets. For targets with Linux kernels 2.5.60 and later, this
3176 enables follow-fork-mode and detach-on-fork for both fork and
3177 vfork, as well as fork and vfork catchpoints.
3179 * The info record command now shows the recording format and the
3180 branch tracing configuration for the current thread when using
3181 the btrace record target.
3182 For the BTS format, it shows the ring buffer size.
3184 * GDB now has support for DTrace USDT (Userland Static Defined
3185 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
3187 * GDB now supports access to vector registers on S/390 GNU/Linux
3190 * Removed command line options
3192 -xdb HP-UX XDB compatibility mode.
3194 * Removed targets and native configurations
3196 HP/PA running HP-UX hppa*-*-hpux*
3197 Itanium running HP-UX ia64-*-hpux*
3199 * New configure options
3202 This configure option allows the user to build GDB with support for
3203 Intel Processor Trace (default: auto). This requires libipt.
3205 --with-libipt-prefix=PATH
3206 Specify the path to the version of libipt that GDB should use.
3207 $PATH/include should contain the intel-pt.h header and
3208 $PATH/lib should contain the libipt.so library.
3210 *** Changes in GDB 7.9.1
3214 ** Xmethods can now specify a result type.
3216 *** Changes in GDB 7.9
3218 * GDB now supports hardware watchpoints on x86 GNU Hurd.
3222 ** You can now access frame registers from Python scripts.
3223 ** New attribute 'producer' for gdb.Symtab objects.
3224 ** gdb.Objfile objects have a new attribute "progspace",
3225 which is the gdb.Progspace object of the containing program space.
3226 ** gdb.Objfile objects have a new attribute "owner".
3227 ** gdb.Objfile objects have a new attribute "build_id",
3228 which is the build ID generated when the file was built.
3229 ** gdb.Objfile objects have a new method "add_separate_debug_file".
3230 ** A new event "gdb.clear_objfiles" has been added, triggered when
3231 selecting a new file to debug.
3232 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
3233 ** New function gdb.lookup_objfile.
3235 New events which are triggered when GDB modifies the state of the
3238 ** gdb.events.inferior_call_pre: Function call is about to be made.
3239 ** gdb.events.inferior_call_post: Function call has just been made.
3240 ** gdb.events.memory_changed: A memory location has been altered.
3241 ** gdb.events.register_changed: A register has been altered.
3243 * New Python-based convenience functions:
3245 ** $_caller_is(name [, number_of_frames])
3246 ** $_caller_matches(regexp [, number_of_frames])
3247 ** $_any_caller_is(name [, number_of_frames])
3248 ** $_any_caller_matches(regexp [, number_of_frames])
3250 * GDB now supports the compilation and injection of source code into
3251 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
3252 to compile the source code to object code, and if successful, inject
3253 and execute that code within the current context of the inferior.
3254 Currently the C language is supported. The commands used to
3255 interface with this new feature are:
3257 compile code [-raw|-r] [--] [source code]
3258 compile file [-raw|-r] filename
3262 demangle [-l language] [--] name
3263 Demangle "name" in the specified language, or the current language
3264 if elided. This command is renamed from the "maint demangle" command.
3265 The latter is kept as a no-op to avoid "maint demangle" being interpreted
3266 as "maint demangler-warning".
3268 queue-signal signal-name-or-number
3269 Queue a signal to be delivered to the thread when it is resumed.
3271 add-auto-load-scripts-directory directory
3272 Add entries to the list of directories from which to load auto-loaded
3275 maint print user-registers
3276 List all currently available "user" registers.
3278 compile code [-r|-raw] [--] [source code]
3279 Compile, inject, and execute in the inferior the executable object
3280 code produced by compiling the provided source code.
3282 compile file [-r|-raw] filename
3283 Compile and inject into the inferior the executable object code
3284 produced by compiling the source code stored in the filename
3287 * On resume, GDB now always passes the signal the program had stopped
3288 for to the thread the signal was sent to, even if the user changed
3289 threads before resuming. Previously GDB would often (but not
3290 always) deliver the signal to the thread that happens to be current
3293 * Conversely, the "signal" command now consistently delivers the
3294 requested signal to the current thread. GDB now asks for
3295 confirmation if the program had stopped for a signal and the user
3296 switched threads meanwhile.
3298 * "breakpoint always-inserted" modes "off" and "auto" merged.
3300 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
3301 won't remove breakpoints from the target until all threads stop,
3302 even in non-stop mode. The "auto" mode has been removed, and "off"
3303 is now the default mode.
3307 set debug symbol-lookup
3308 show debug symbol-lookup
3309 Control display of debugging info regarding symbol lookup.
3313 ** The -list-thread-groups command outputs an exit-code field for
3314 inferiors that have exited.
3318 MIPS SDE mips*-sde*-elf*
3322 Support for these obsolete configurations has been removed.
3324 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
3325 SGI Irix-5.x mips-*-irix5*
3326 SGI Irix-6.x mips-*-irix6*
3327 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
3328 VAX running Ultrix vax-*-ultrix*
3330 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3331 and "assf"), have been removed. Use the "sharedlibrary" command, or
3332 its alias "share", instead.
3334 *** Changes in GDB 7.8
3336 * New command line options
3339 This is an alias for the --data-directory option.
3341 * GDB supports printing and modifying of variable length automatic arrays
3342 as specified in ISO C99.
3344 * The ARM simulator now supports instruction level tracing
3345 with or without disassembly.
3349 GDB now has support for scripting using Guile. Whether this is
3350 available is determined at configure time.
3351 Guile version 2.0 or greater is required.
3352 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
3354 * New commands (for set/show, see "New options" below)
3358 Invoke CODE by passing it to the Guile interpreter.
3362 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
3364 info auto-load guile-scripts [regexp]
3365 Print the list of automatically loaded Guile scripts.
3367 * The source command is now capable of sourcing Guile scripts.
3368 This feature is dependent on the debugger being built with Guile support.
3372 set print symbol-loading (off|brief|full)
3373 show print symbol-loading
3374 Control whether to print informational messages when loading symbol
3375 information for a file. The default is "full", but when debugging
3376 programs with large numbers of shared libraries the amount of output
3377 becomes less useful.
3379 set guile print-stack (none|message|full)
3380 show guile print-stack
3381 Show a stack trace when an error is encountered in a Guile script.
3383 set auto-load guile-scripts (on|off)
3384 show auto-load guile-scripts
3385 Control auto-loading of Guile script files.
3387 maint ada set ignore-descriptive-types (on|off)
3388 maint ada show ignore-descriptive-types
3389 Control whether the debugger should ignore descriptive types in Ada
3390 programs. The default is not to ignore the descriptive types. See
3391 the user manual for more details on descriptive types and the intended
3392 usage of this option.
3394 set auto-connect-native-target
3396 Control whether GDB is allowed to automatically connect to the
3397 native target for the run, attach, etc. commands when not connected
3398 to any target yet. See also "target native" below.
3400 set record btrace replay-memory-access (read-only|read-write)
3401 show record btrace replay-memory-access
3402 Control what memory accesses are allowed during replay.
3404 maint set target-async (on|off)
3405 maint show target-async
3406 This controls whether GDB targets operate in synchronous or
3407 asynchronous mode. Normally the default is asynchronous, if it is
3408 available; but this can be changed to more easily debug problems
3409 occurring only in synchronous mode.
3411 set mi-async (on|off)
3413 Control whether MI asynchronous mode is preferred. This supersedes
3414 "set target-async" of previous GDB versions.
3416 * "set target-async" is deprecated as a CLI option and is now an alias
3417 for "set mi-async" (only puts MI into async mode).
3419 * Background execution commands (e.g., "c&", "s&", etc.) are now
3420 possible ``out of the box'' if the target supports them. Previously
3421 the user would need to explicitly enable the possibility with the
3422 "set target-async on" command.
3424 * New features in the GDB remote stub, GDBserver
3426 ** New option --debug-format=option1[,option2,...] allows one to add
3427 additional text to each output. At present only timestamps
3428 are supported: --debug-format=timestamps.
3429 Timestamps can also be turned on with the
3430 "monitor set debug-format timestamps" command from GDB.
3432 * The 'record instruction-history' command now starts counting instructions
3433 at one. This also affects the instruction ranges reported by the
3434 'record function-call-history' command when given the /i modifier.
3436 * The command 'record function-call-history' supports a new modifier '/c' to
3437 indent the function names based on their call stack depth.
3438 The fields for the '/i' and '/l' modifier have been reordered.
3439 The source line range is now prefixed with 'at'.
3440 The instruction range is now prefixed with 'inst'.
3441 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
3442 "record instruction-history" and "list" commands.
3444 * The ranges given as arguments to the 'record function-call-history' and
3445 'record instruction-history' commands are now inclusive.
3447 * The btrace record target now supports the 'record goto' command.
3448 For locations inside the execution trace, the back trace is computed
3449 based on the information stored in the execution trace.
3451 * The btrace record target supports limited reverse execution and replay.
3452 The target does not record data and therefore does not allow reading
3453 memory or registers.
3455 * The "catch syscall" command now works on s390*-linux* targets.
3457 * The "compare-sections" command is no longer specific to target
3458 remote. It now works with all targets.
3460 * All native targets are now consistently called "native".
3461 Consequently, the "target child", "target GNU", "target djgpp",
3462 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
3463 commands have been replaced with "target native". The QNX/NTO port
3464 leaves the "procfs" target in place and adds a "native" target for
3465 consistency with other ports. The impact on users should be minimal
3466 as these commands previously either throwed an error, or were
3467 no-ops. The target's name is visible in the output of the following
3468 commands: "help target", "info target", "info files", "maint print
3471 * The "target native" command now connects to the native target. This
3472 can be used to launch native programs even when "set
3473 auto-connect-native-target" is set to off.
3475 * GDB now supports access to Intel MPX registers on GNU/Linux.
3477 * Support for Intel AVX-512 registers on GNU/Linux.
3478 Support displaying and modifying Intel AVX-512 registers
3479 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
3481 * New remote packets
3483 qXfer:btrace:read's annex
3484 The qXfer:btrace:read packet supports a new annex 'delta' to read
3485 branch trace incrementally.
3489 ** Valid Python operations on gdb.Value objects representing
3490 structs/classes invoke the corresponding overloaded operators if
3492 ** New `Xmethods' feature in the Python API. Xmethods are
3493 additional methods or replacements for existing methods of a C++
3494 class. This feature is useful for those cases where a method
3495 defined in C++ source code could be inlined or optimized out by
3496 the compiler, making it unavailable to GDB.
3499 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
3501 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
3502 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
3503 its alias "share", instead.
3505 * The commands "set remotebaud" and "show remotebaud" are no longer
3506 supported. Use "set serial baud" and "show serial baud" (respectively)
3511 ** A new option "-gdb-set mi-async" replaces "-gdb-set
3512 target-async". The latter is left as a deprecated alias of the
3513 former for backward compatibility. If the target supports it,
3514 CLI background execution commands are now always possible by
3515 default, independently of whether the frontend stated a
3516 preference for asynchronous execution with "-gdb-set mi-async".
3517 Previously "-gdb-set target-async off" affected both MI execution
3518 commands and CLI execution commands.
3520 *** Changes in GDB 7.7
3522 * Improved support for process record-replay and reverse debugging on
3523 arm*-linux* targets. Support for thumb32 and syscall instruction
3524 recording has been added.
3526 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
3528 * GDB now supports Fission DWP file format version 2.
3529 http://gcc.gnu.org/wiki/DebugFission
3531 * New convenience function "$_isvoid", to check whether an expression
3532 is void. A void expression is an expression where the type of the
3533 result is "void". For example, some convenience variables may be
3534 "void" when evaluated (e.g., "$_exitcode" before the execution of
3535 the program being debugged; or an undefined convenience variable).
3536 Another example, when calling a function whose return type is
3539 * The "maintenance print objfiles" command now takes an optional regexp.
3541 * The "catch syscall" command now works on arm*-linux* targets.
3543 * GDB now consistently shows "<not saved>" when printing values of
3544 registers the debug info indicates have not been saved in the frame
3545 and there's nowhere to retrieve them from
3546 (callee-saved/call-clobbered registers):
3551 (gdb) info registers rax
3554 Before, the former would print "<optimized out>", and the latter
3555 "*value not available*".
3557 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
3562 ** Frame filters and frame decorators have been added.
3563 ** Temporary breakpoints are now supported.
3564 ** Line tables representation has been added.
3565 ** New attribute 'parent_type' for gdb.Field objects.
3566 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
3567 ** New attribute 'name' for gdb.Type objects.
3571 Nios II ELF nios2*-*-elf
3572 Nios II GNU/Linux nios2*-*-linux
3573 Texas Instruments MSP430 msp430*-*-elf
3575 * Removed native configurations
3577 Support for these a.out NetBSD and OpenBSD obsolete configurations has
3578 been removed. ELF variants of these configurations are kept supported.
3580 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
3581 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
3582 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
3583 i[34567]86-*-openbsd3.[0-3]
3584 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
3585 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
3586 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
3590 Like "catch throw", but catches a re-thrown exception.
3591 maint check-psymtabs
3592 Renamed from old "maint check-symtabs".
3594 Perform consistency checks on symtabs.
3595 maint expand-symtabs
3596 Expand symtabs matching an optional regexp.
3599 Display the details of GDB configure-time options.
3601 maint set|show per-command
3602 maint set|show per-command space
3603 maint set|show per-command time
3604 maint set|show per-command symtab
3605 Enable display of per-command gdb resource usage.
3607 remove-symbol-file FILENAME
3608 remove-symbol-file -a ADDRESS
3609 Remove a symbol file added via add-symbol-file. The file to remove
3610 can be identified by its filename or by an address that lies within
3611 the boundaries of this symbol file in memory.
3614 info exceptions REGEXP
3615 Display the list of Ada exceptions defined in the program being
3616 debugged. If provided, only the exceptions whose names match REGEXP
3621 set debug symfile off|on
3623 Control display of debugging info regarding reading symbol files and
3624 symbol tables within those files
3626 set print raw frame-arguments
3627 show print raw frame-arguments
3628 Set/show whether to print frame arguments in raw mode,
3629 disregarding any defined pretty-printers.
3631 set remote trace-status-packet
3632 show remote trace-status-packet
3633 Set/show the use of remote protocol qTStatus packet.
3637 Control display of debugging messages related to Nios II targets.
3641 Control whether target-assisted range stepping is enabled.
3643 set startup-with-shell
3644 show startup-with-shell
3645 Specifies whether Unix child processes are started via a shell or
3650 Use the target memory cache for accesses to the code segment. This
3651 improves performance of remote debugging (particularly disassembly).
3653 * You can now use a literal value 'unlimited' for options that
3654 interpret 0 or -1 as meaning "unlimited". E.g., "set
3655 trace-buffer-size unlimited" is now an alias for "set
3656 trace-buffer-size -1" and "set height unlimited" is now an alias for
3659 * The "set debug symtab-create" debugging option of GDB has been changed to
3660 accept a verbosity level. 0 means "off", 1 provides basic debugging
3661 output, and values of 2 or greater provides more verbose output.
3663 * New command-line options
3665 Display the details of GDB configure-time options.
3667 * The command 'tsave' can now support new option '-ctf' to save trace
3668 buffer in Common Trace Format.
3670 * Newly installed $prefix/bin/gcore acts as a shell interface for the
3673 * GDB now implements the C++ 'typeid' operator.
3675 * The new convenience variable $_exception holds the exception being
3676 thrown or caught at an exception-related catchpoint.
3678 * The exception-related catchpoints, like "catch throw", now accept a
3679 regular expression which can be used to filter exceptions by type.
3681 * The new convenience variable $_exitsignal is automatically set to
3682 the terminating signal number when the program being debugged dies
3683 due to an uncaught signal.
3687 ** All MI commands now accept an optional "--language" option.
3688 Support for this feature can be verified by using the "-list-features"
3689 command, which should contain "language-option".
3691 ** The new command -info-gdb-mi-command allows the user to determine
3692 whether a GDB/MI command is supported or not.
3694 ** The "^error" result record returned when trying to execute an undefined
3695 GDB/MI command now provides a variable named "code" whose content is the
3696 "undefined-command" error code. Support for this feature can be verified
3697 by using the "-list-features" command, which should contain
3698 "undefined-command-error-code".
3700 ** The -trace-save MI command can optionally save trace buffer in Common
3703 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
3705 ** The command -data-list-register-values now accepts an optional
3706 "--skip-unavailable" option. When used, only the available registers
3709 ** The new command -trace-frame-collected dumps collected variables,
3710 computed expressions, tvars, memory and registers in a traceframe.
3712 ** The commands -stack-list-locals, -stack-list-arguments and
3713 -stack-list-variables now accept an option "--skip-unavailable".
3714 When used, only the available locals or arguments are displayed.
3716 ** The -exec-run command now accepts an optional "--start" option.
3717 When used, the command follows the same semantics as the "start"
3718 command, stopping the program's execution at the start of its
3719 main subprogram. Support for this feature can be verified using
3720 the "-list-features" command, which should contain
3721 "exec-run-start-option".
3723 ** The new commands -catch-assert and -catch-exceptions insert
3724 catchpoints stopping the program when Ada exceptions are raised.
3726 ** The new command -info-ada-exceptions provides the equivalent of
3727 the new "info exceptions" command.
3729 * New system-wide configuration scripts
3730 A GDB installation now provides scripts suitable for use as system-wide
3731 configuration scripts for the following systems:
3735 * GDB now supports target-assigned range stepping with remote targets.
3736 This improves the performance of stepping source lines by reducing
3737 the number of control packets from/to GDB. See "New remote packets"
3740 * GDB now understands the element 'tvar' in the XML traceframe info.
3741 It has the id of the collected trace state variables.
3743 * On S/390 targets that provide the transactional-execution feature,
3744 the program interruption transaction diagnostic block (TDB) is now
3745 represented as a number of additional "registers" in GDB.
3747 * New remote packets
3751 The vCont packet supports a new 'r' action, that tells the remote
3752 stub to step through an address range itself, without GDB
3753 involvemement at each single-step.
3755 qXfer:libraries-svr4:read's annex
3756 The previously unused annex of the qXfer:libraries-svr4:read packet
3757 is now used to support passing an argument list. The remote stub
3758 reports support for this argument list to GDB's qSupported query.
3759 The defined arguments are "start" and "prev", used to reduce work
3760 necessary for library list updating, resulting in significant
3763 * New features in the GDB remote stub, GDBserver
3765 ** GDBserver now supports target-assisted range stepping. Currently
3766 enabled on x86/x86_64 GNU/Linux targets.
3768 ** GDBserver now adds element 'tvar' in the XML in the reply to
3769 'qXfer:traceframe-info:read'. It has the id of the collected
3770 trace state variables.
3772 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
3775 * New 'z' formatter for printing and examining memory, this displays the
3776 value as hexadecimal zero padded on the left to the size of the type.
3778 * GDB can now use Windows x64 unwinding data.
3780 * The "set remotebaud" command has been replaced by "set serial baud".
3781 Similarly, "show remotebaud" has been replaced by "show serial baud".
3782 The "set remotebaud" and "show remotebaud" commands are still available
3783 to provide backward compatibility with older versions of GDB.
3785 *** Changes in GDB 7.6
3787 * Target record has been renamed to record-full.
3788 Record/replay is now enabled with the "record full" command.
3789 This also affects settings that are associated with full record/replay
3790 that have been moved from "set/show record" to "set/show record full":
3792 set|show record full insn-number-max
3793 set|show record full stop-at-limit
3794 set|show record full memory-query
3796 * A new record target "record-btrace" has been added. The new target
3797 uses hardware support to record the control-flow of a process. It
3798 does not support replaying the execution, but it implements the
3799 below new commands for investigating the recorded execution log.
3800 This new recording method can be enabled using:
3804 The "record-btrace" target is only available on Intel Atom processors
3805 and requires a Linux kernel 2.6.32 or later.
3807 * Two new commands have been added for record/replay to give information
3808 about the recorded execution without having to replay the execution.
3809 The commands are only supported by "record btrace".
3811 record instruction-history prints the execution history at
3812 instruction granularity
3814 record function-call-history prints the execution history at
3815 function granularity
3817 * New native configurations
3819 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
3820 FreeBSD/powerpc powerpc*-*-freebsd
3821 x86_64/Cygwin x86_64-*-cygwin*
3822 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
3826 ARM AArch64 aarch64*-*-elf
3827 ARM AArch64 GNU/Linux aarch64*-*-linux
3828 Lynx 178 PowerPC powerpc-*-lynx*178
3829 x86_64/Cygwin x86_64-*-cygwin*
3830 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
3832 * If the configured location of system.gdbinit file (as given by the
3833 --with-system-gdbinit option at configure time) is in the
3834 data-directory (as specified by --with-gdb-datadir at configure
3835 time) or in one of its subdirectories, then GDB will look for the
3836 system-wide init file in the directory specified by the
3837 --data-directory command-line option.
3839 * New command line options:
3841 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
3842 other initialization files, unlike -nx which disables all of them.
3844 * Removed command line options
3846 -epoch This was used by the gdb mode in Epoch, an ancient fork of
3849 * The 'ptype' and 'whatis' commands now accept an argument to control
3852 * 'info proc' now works on some core files.
3856 ** Vectors can be created with gdb.Type.vector.
3858 ** Python's atexit.register now works in GDB.
3860 ** Types can be pretty-printed via a Python API.
3862 ** Python 3 is now supported (in addition to Python 2.4 or later)
3864 ** New class gdb.Architecture exposes GDB's internal representation
3865 of architecture in the Python API.
3867 ** New method Frame.architecture returns the gdb.Architecture object
3868 corresponding to the frame's architecture.
3870 * New Python-based convenience functions:
3872 ** $_memeq(buf1, buf2, length)
3873 ** $_streq(str1, str2)
3875 ** $_regex(str, regex)
3877 * The 'cd' command now defaults to using '~' (the home directory) if not
3880 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
3881 default for GCC since November 2000.
3883 * The command 'forward-search' can now be abbreviated as 'fo'.
3885 * The command 'info tracepoints' can now display 'installed on target'
3886 or 'not installed on target' for each non-pending location of tracepoint.
3888 * New configure options
3890 --enable-libmcheck/--disable-libmcheck
3891 By default, development versions are built with -lmcheck on hosts
3892 that support it, in order to help track memory corruption issues.
3893 Release versions, on the other hand, are built without -lmcheck
3894 by default. The --enable-libmcheck/--disable-libmcheck configure
3895 options allow the user to override that default.
3896 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
3897 This configure option allows the user to build GDB with
3898 libbabeltrace using which GDB can read Common Trace Format data.
3900 * New commands (for set/show, see "New options" below)
3903 Catch signals. This is similar to "handle", but allows commands and
3904 conditions to be attached.
3907 List the BFDs known to GDB.
3909 python-interactive [command]
3911 Start a Python interactive prompt, or evaluate the optional command
3912 and print the result of expressions.
3915 "py" is a new alias for "python".
3917 enable type-printer [name]...
3918 disable type-printer [name]...
3919 Enable or disable type printers.
3923 ** For the Renesas Super-H architecture, the "regs" command has been removed
3924 (has been deprecated in GDB 7.5), and "info all-registers" should be used
3929 set print type methods (on|off)
3930 show print type methods
3931 Control whether method declarations are displayed by "ptype".
3932 The default is to show them.
3934 set print type typedefs (on|off)
3935 show print type typedefs
3936 Control whether typedef definitions are displayed by "ptype".
3937 The default is to show them.
3939 set filename-display basename|relative|absolute
3940 show filename-display
3941 Control the way in which filenames is displayed.
3942 The default is "relative", which preserves previous behavior.
3944 set trace-buffer-size
3945 show trace-buffer-size
3946 Request target to change the size of trace buffer.
3948 set remote trace-buffer-size-packet auto|on|off
3949 show remote trace-buffer-size-packet
3950 Control the use of the remote protocol `QTBuffer:size' packet.
3954 Control display of debugging messages related to ARM AArch64.
3957 set debug coff-pe-read
3958 show debug coff-pe-read
3959 Control display of debugging messages related to reading of COFF/PE
3964 Control display of debugging messages related to Mach-O symbols
3967 set debug notification
3968 show debug notification
3969 Control display of debugging info for async remote notification.
3973 ** Command parameter changes are now notified using new async record
3974 "=cmd-param-changed".
3975 ** Trace frame changes caused by command "tfind" are now notified using
3976 new async record "=traceframe-changed".
3977 ** The creation, deletion and modification of trace state variables
3978 are now notified using new async records "=tsv-created",
3979 "=tsv-deleted" and "=tsv-modified".
3980 ** The start and stop of process record are now notified using new
3981 async record "=record-started" and "=record-stopped".
3982 ** Memory changes are now notified using new async record
3984 ** The data-disassemble command response will include a "fullname" field
3985 containing the absolute file name when source has been requested.
3986 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
3987 command, to allow pattern filling of memory areas.
3988 ** New commands "-catch-load"/"-catch-unload" added for intercepting
3989 library load/unload events.
3990 ** The response to breakpoint commands and breakpoint async records
3991 includes an "installed" field containing a boolean state about each
3992 non-pending tracepoint location is whether installed on target or not.
3993 ** Output of the "-trace-status" command includes a "trace-file" field
3994 containing the name of the trace file being examined. This field is
3995 optional, and only present when examining a trace file.
3996 ** The "fullname" field is now always present along with the "file" field,
3997 even if the file cannot be found by GDB.
3999 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
4000 You must have the LZMA library available when configuring GDB for this
4001 feature to be enabled. For more information, see:
4002 http://fedoraproject.org/wiki/Features/MiniDebugInfo
4004 * New remote packets
4007 Set the size of trace buffer. The remote stub reports support for this
4008 packet to gdb's qSupported query.
4011 Enable Branch Trace Store (BTS)-based branch tracing for the current
4012 thread. The remote stub reports support for this packet to gdb's
4016 Disable branch tracing for the current thread. The remote stub reports
4017 support for this packet to gdb's qSupported query.
4020 Read the traced branches for the current thread. The remote stub
4021 reports support for this packet to gdb's qSupported query.
4023 *** Changes in GDB 7.5
4025 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
4026 for more x32 ABI info.
4028 * GDB now supports access to MIPS DSP registers on Linux targets.
4030 * GDB now supports debugging microMIPS binaries.
4032 * The "info os" command on GNU/Linux can now display information on
4033 several new classes of objects managed by the operating system:
4034 "info os procgroups" lists process groups
4035 "info os files" lists file descriptors
4036 "info os sockets" lists internet-domain sockets
4037 "info os shm" lists shared-memory regions
4038 "info os semaphores" lists semaphores
4039 "info os msg" lists message queues
4040 "info os modules" lists loaded kernel modules
4042 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
4043 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
4044 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
4045 options and inspect the probe arguments using the new $_probe_arg family
4046 of convenience variables. You can obtain more information about SystemTap
4047 in <http://sourceware.org/systemtap/>.
4049 * GDB now supports reversible debugging on ARM, it allows you to
4050 debug basic ARM and THUMB instructions, and provides
4051 record/replay support.
4053 * The option "symbol-reloading" has been deleted as it is no longer used.
4057 ** GDB commands implemented in Python can now be put in command class
4060 ** The "maint set python print-stack on|off" is now deleted.
4062 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
4063 apply "flag enum"-style pretty-printing to any enum.
4065 ** gdb.lookup_symbol can now work when there is no current frame.
4067 ** gdb.Symbol now has a 'line' attribute, holding the line number in
4068 the source at which the symbol was defined.
4070 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
4071 method 'value'. The former indicates whether the symbol needs a
4072 frame in order to compute its value, and the latter computes the
4075 ** A new method 'referenced_value' on gdb.Value objects which can
4076 dereference pointer as well as C++ reference values.
4078 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
4079 which return the global and static blocks (as gdb.Block objects),
4080 of the underlying symbol table, respectively.
4082 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
4083 object associated with a PC value.
4085 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
4086 of the address range occupied by code for the current source line.
4088 * Go language support.
4089 GDB now supports debugging programs written in the Go programming
4092 * GDBserver now supports stdio connections.
4093 E.g. (gdb) target remote | ssh myhost gdbserver - hello
4095 * The binary "gdbtui" can no longer be built or installed.
4096 Use "gdb -tui" instead.
4098 * GDB will now print "flag" enums specially. A flag enum is one where
4099 all the enumerator values have no bits in common when pairwise
4100 "and"ed. When printing a value whose type is a flag enum, GDB will
4101 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
4102 (gdb) print (enum E) 3
4105 * The filename part of a linespec will now match trailing components
4106 of a source file name. For example, "break gcc/expr.c:1000" will
4107 now set a breakpoint in build/gcc/expr.c, but not
4108 build/libcpp/expr.c.
4110 * The "info proc" and "generate-core-file" commands will now also
4111 work on remote targets connected to GDBserver on Linux.
4113 * The command "info catch" has been removed. It has been disabled
4114 since December 2007.
4116 * The "catch exception" and "catch assert" commands now accept
4117 a condition at the end of the command, much like the "break"
4118 command does. For instance:
4120 (gdb) catch exception Constraint_Error if Barrier = True
4122 Previously, it was possible to add a condition to such catchpoints,
4123 but it had to be done as a second step, after the catchpoint had been
4124 created, using the "condition" command.
4126 * The "info static-tracepoint-marker" command will now also work on
4127 native Linux targets with in-process agent.
4129 * GDB can now set breakpoints on inlined functions.
4131 * The .gdb_index section has been updated to include symbols for
4132 inlined functions. GDB will ignore older .gdb_index sections by
4133 default, which could cause symbol files to be loaded more slowly
4134 until their .gdb_index sections can be recreated. The new command
4135 "set use-deprecated-index-sections on" will cause GDB to use any older
4136 .gdb_index sections it finds. This will restore performance, but the
4137 ability to set breakpoints on inlined functions will be lost in symbol
4138 files with older .gdb_index sections.
4140 The .gdb_index section has also been updated to record more information
4141 about each symbol. This speeds up the "info variables", "info functions"
4142 and "info types" commands when used with programs having the .gdb_index
4143 section, as well as speeding up debugging with shared libraries using
4144 the .gdb_index section.
4146 * Ada support for GDB/MI Variable Objects has been added.
4148 * GDB can now support 'breakpoint always-inserted mode' in 'record'
4153 ** New command -info-os is the MI equivalent of "info os".
4155 ** Output logs ("set logging" and related) now include MI output.
4159 ** "set use-deprecated-index-sections on|off"
4160 "show use-deprecated-index-sections on|off"
4161 Controls the use of deprecated .gdb_index sections.
4163 ** "catch load" and "catch unload" can be used to stop when a shared
4164 library is loaded or unloaded, respectively.
4166 ** "enable count" can be used to auto-disable a breakpoint after
4169 ** "info vtbl" can be used to show the virtual method tables for
4170 C++ and Java objects.
4172 ** "explore" and its sub commands "explore value" and "explore type"
4173 can be used to recursively explore values and types of
4174 expressions. These commands are available only if GDB is
4175 configured with '--with-python'.
4177 ** "info auto-load" shows status of all kinds of auto-loaded files,
4178 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
4179 sequences of commands files, "info auto-load python-scripts"
4180 shows status of auto-loading Python script files,
4181 "info auto-load local-gdbinit" shows status of loading init file
4182 (.gdbinit) from current directory and "info auto-load libthread-db" shows
4183 status of inferior specific thread debugging shared library loading.
4185 ** "info auto-load-scripts", "set auto-load-scripts on|off"
4186 and "show auto-load-scripts" commands have been deprecated, use their
4187 "info auto-load python-scripts", "set auto-load python-scripts on|off"
4188 and "show auto-load python-scripts" counterparts instead.
4190 ** "dprintf location,format,args..." creates a dynamic printf, which
4191 is basically a breakpoint that does a printf and immediately
4192 resumes your program's execution, so it is like a printf that you
4193 can insert dynamically at runtime instead of at compiletime.
4195 ** "set print symbol"
4197 Controls whether GDB attempts to display the symbol, if any,
4198 corresponding to addresses it prints. This defaults to "on", but
4199 you can set it to "off" to restore GDB's previous behavior.
4201 * Deprecated commands
4203 ** For the Renesas Super-H architecture, the "regs" command has been
4204 deprecated, and "info all-registers" should be used instead.
4208 Renesas RL78 rl78-*-elf
4209 HP OpenVMS ia64 ia64-hp-openvms*
4211 * GDBserver supports evaluation of breakpoint conditions. When
4212 support is advertised by GDBserver, GDB may be told to send the
4213 breakpoint conditions in bytecode form to GDBserver. GDBserver
4214 will only report the breakpoint trigger to GDB when its condition
4219 set mips compression
4220 show mips compression
4221 Select the compressed ISA encoding used in functions that have no symbol
4222 information available. The encoding can be set to either of:
4225 and is updated automatically from ELF file flags if available.
4227 set breakpoint condition-evaluation
4228 show breakpoint condition-evaluation
4229 Control whether breakpoint conditions are evaluated by GDB ("host") or by
4230 GDBserver ("target"). Default option "auto" chooses the most efficient
4232 This option can improve debugger efficiency depending on the speed of the
4236 Disable auto-loading globally.
4239 Show auto-loading setting of all kinds of auto-loaded files.
4241 set auto-load gdb-scripts on|off
4242 show auto-load gdb-scripts
4243 Control auto-loading of GDB canned sequences of commands files.
4245 set auto-load python-scripts on|off
4246 show auto-load python-scripts
4247 Control auto-loading of Python script files.
4249 set auto-load local-gdbinit on|off
4250 show auto-load local-gdbinit
4251 Control loading of init file (.gdbinit) from current directory.
4253 set auto-load libthread-db on|off
4254 show auto-load libthread-db
4255 Control auto-loading of inferior specific thread debugging shared library.
4257 set auto-load scripts-directory <dir1>[:<dir2>...]
4258 show auto-load scripts-directory
4259 Set a list of directories from which to load auto-loaded scripts.
4260 Automatically loaded Python scripts and GDB scripts are located in one
4261 of the directories listed by this option.
4262 The delimiter (':' above) may differ according to the host platform.
4264 set auto-load safe-path <dir1>[:<dir2>...]
4265 show auto-load safe-path
4266 Set a list of directories from which it is safe to auto-load files.
4267 The delimiter (':' above) may differ according to the host platform.
4269 set debug auto-load on|off
4270 show debug auto-load
4271 Control display of debugging info for auto-loading the files above.
4273 set dprintf-style gdb|call|agent
4275 Control the way in which a dynamic printf is performed; "gdb"
4276 requests a GDB printf command, while "call" causes dprintf to call a
4277 function in the inferior. "agent" requests that the target agent
4278 (such as GDBserver) do the printing.
4280 set dprintf-function <expr>
4281 show dprintf-function
4282 set dprintf-channel <expr>
4283 show dprintf-channel
4284 Set the function and optional first argument to the call when using
4285 the "call" style of dynamic printf.
4287 set disconnected-dprintf on|off
4288 show disconnected-dprintf
4289 Control whether agent-style dynamic printfs continue to be in effect
4290 after GDB disconnects.
4292 * New configure options
4294 --with-auto-load-dir
4295 Configure default value for the 'set auto-load scripts-directory'
4296 setting above. It defaults to '$debugdir:$datadir/auto-load',
4297 $debugdir representing global debugging info directories (available
4298 via 'show debug-file-directory') and $datadir representing GDB's data
4299 directory (available via 'show data-directory').
4301 --with-auto-load-safe-path
4302 Configure default value for the 'set auto-load safe-path' setting
4303 above. It defaults to the --with-auto-load-dir setting.
4305 --without-auto-load-safe-path
4306 Set 'set auto-load safe-path' to '/', effectively disabling this
4309 * New remote packets
4311 z0/z1 conditional breakpoints extension
4313 The z0/z1 breakpoint insertion packets have been extended to carry
4314 a list of conditional expressions over to the remote stub depending on the
4315 condition evaluation mode. The use of this extension can be controlled
4316 via the "set remote conditional-breakpoints-packet" command.
4320 Specify the signals which the remote stub may pass to the debugged
4321 program without GDB involvement.
4323 * New command line options
4325 --init-command=FILE, -ix Like --command, -x but execute it
4326 before loading inferior.
4327 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
4328 execute it before loading inferior.
4330 *** Changes in GDB 7.4
4332 * GDB now handles ambiguous linespecs more consistently; the existing
4333 FILE:LINE support has been expanded to other types of linespecs. A
4334 breakpoint will now be set on all matching locations in all
4335 inferiors, and locations will be added or removed according to
4338 * GDB now allows you to skip uninteresting functions and files when
4339 stepping with the "skip function" and "skip file" commands.
4341 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
4342 and "show remote hardware-watchpoint-length-limit". These allows to
4343 set or show the maximum length limit (in bytes) of a remote
4344 target hardware watchpoint.
4346 This allows e.g. to use "unlimited" hardware watchpoints with the
4347 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
4348 watchpoints are slower than real hardware watchpoints but are
4349 significantly faster than gdb software watchpoints.
4353 ** The register_pretty_printer function in module gdb.printing now takes
4354 an optional `replace' argument. If True, the new printer replaces any
4357 ** The "maint set python print-stack on|off" command has been
4358 deprecated and will be deleted in GDB 7.5.
4359 A new command: "set python print-stack none|full|message" has
4360 replaced it. Additionally, the default for "print-stack" is
4361 now "message", which just prints the error message without
4364 ** A prompt substitution hook (prompt_hook) is now available to the
4367 ** A new Python module, gdb.prompt has been added to the GDB Python
4368 modules library. This module provides functionality for
4369 escape sequences in prompts (used by set/show
4370 extended-prompt). These escape sequences are replaced by their
4371 corresponding value.
4373 ** Python commands and convenience-functions located in
4374 'data-directory'/python/gdb/command and
4375 'data-directory'/python/gdb/function are now automatically loaded
4378 ** Blocks now provide four new attributes. global_block and
4379 static_block will return the global and static blocks
4380 respectively. is_static and is_global are boolean attributes
4381 that indicate if the block is one of those two types.
4383 ** Symbols now provide the "type" attribute, the type of the symbol.
4385 ** The "gdb.breakpoint" function has been deprecated in favor of
4388 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
4389 of a function. This class is based on the "finish" command
4390 available in the CLI.
4392 ** Type objects for struct and union types now allow access to
4393 the fields using standard Python dictionary (mapping) methods.
4394 For example, "some_type['myfield']" now works, as does
4395 "some_type.items()".
4397 ** A new event "gdb.new_objfile" has been added, triggered by loading a
4400 ** A new function, "deep_items" has been added to the gdb.types
4401 module in the GDB Python modules library. This function returns
4402 an iterator over the fields of a struct or union type. Unlike
4403 the standard Python "iteritems" method, it will recursively traverse
4404 any anonymous fields.
4408 ** "*stopped" events can report several new "reason"s, such as
4411 ** Breakpoint changes are now notified using new async records, like
4412 "=breakpoint-modified".
4414 ** New command -ada-task-info.
4416 * libthread-db-search-path now supports two special values: $sdir and $pdir.
4417 $sdir specifies the default system locations of shared libraries.
4418 $pdir specifies the directory where the libpthread used by the application
4421 GDB no longer looks in $sdir and $pdir after it has searched the directories
4422 mentioned in libthread-db-search-path. If you want to search those
4423 directories, they must be specified in libthread-db-search-path.
4424 The default value of libthread-db-search-path on GNU/Linux and Solaris
4425 systems is now "$sdir:$pdir".
4427 $pdir is not supported by gdbserver, it is currently ignored.
4428 $sdir is supported by gdbserver.
4430 * New configure option --with-iconv-bin.
4431 When using the internationalization support like the one in the GNU C
4432 library, GDB will invoke the "iconv" program to get a list of supported
4433 character sets. If this program lives in a non-standard location, one can
4434 use this option to specify where to find it.
4436 * When natively debugging programs on PowerPC BookE processors running
4437 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
4438 watchpoints, which specify a mask in addition to an address to watch.
4439 The mask specifies that some bits of an address (the bits which are
4440 reset in the mask) should be ignored when matching the address accessed
4441 by the inferior against the watchpoint address. See the "PowerPC Embedded"
4442 section in the user manual for more details.
4444 * The new option --once causes GDBserver to stop listening for connections once
4445 the first connection is made. The listening port used by GDBserver will
4446 become available after that.
4448 * New commands "info macros" and "alias" have been added.
4450 * New function parameters suffix @entry specifies value of function parameter
4451 at the time the function got called. Entry values are available only since
4457 "!" is now an alias of the "shell" command.
4458 Note that no space is needed between "!" and SHELL COMMAND.
4462 watch EXPRESSION mask MASK_VALUE
4463 The watch command now supports the mask argument which allows creation
4464 of masked watchpoints, if the current architecture supports this feature.
4466 info auto-load-scripts [REGEXP]
4467 This command was formerly named "maintenance print section-scripts".
4468 It is now generally useful and is no longer a maintenance-only command.
4470 info macro [-all] [--] MACRO
4471 The info macro command has new options `-all' and `--'. The first for
4472 printing all definitions of a macro. The second for explicitly specifying
4473 the end of arguments and the beginning of the macro name in case the macro
4474 name starts with a hyphen.
4476 collect[/s] EXPRESSIONS
4477 The tracepoint collect command now takes an optional modifier "/s"
4478 that directs it to dereference pointer-to-character types and
4479 collect the bytes of memory up to a zero byte. The behavior is
4480 similar to what you see when you use the regular print command on a
4481 string. An optional integer following the "/s" sets a bound on the
4482 number of bytes that will be collected.
4485 The trace start command now interprets any supplied arguments as a
4486 note to be recorded with the trace run, with an effect similar to
4487 setting the variable trace-notes.
4490 The trace stop command now interprets any arguments as a note to be
4491 mentioned along with the tstatus report that the trace was stopped
4492 with a command. The effect is similar to setting the variable
4495 * Tracepoints can now be enabled and disabled at any time after a trace
4496 experiment has been started using the standard "enable" and "disable"
4497 commands. It is now possible to start a trace experiment with no enabled
4498 tracepoints; GDB will display a warning, but will allow the experiment to
4499 begin, assuming that tracepoints will be enabled as needed while the trace
4502 * Fast tracepoints on 32-bit x86-architectures can now be placed at
4503 locations with 4-byte instructions, when they were previously
4504 limited to locations with instructions of 5 bytes or longer.
4508 set debug dwarf2-read
4509 show debug dwarf2-read
4510 Turns on or off display of debugging messages related to reading
4511 DWARF debug info. The default is off.
4513 set debug symtab-create
4514 show debug symtab-create
4515 Turns on or off display of debugging messages related to symbol table
4516 creation. The default is off.
4519 show extended-prompt
4520 Set the GDB prompt, and allow escape sequences to be inserted to
4521 display miscellaneous information (see 'help set extended-prompt'
4522 for the list of sequences). This prompt (and any information
4523 accessed through the escape sequences) is updated every time the
4524 prompt is displayed.
4526 set print entry-values (both|compact|default|if-needed|no|only|preferred)
4527 show print entry-values
4528 Set printing of frame argument values at function entry. In some cases
4529 GDB can determine the value of function argument which was passed by the
4530 function caller, even if the value was modified inside the called function.
4532 set debug entry-values
4533 show debug entry-values
4534 Control display of debugging info for determining frame argument values at
4535 function entry and virtual tail call frames.
4537 set basenames-may-differ
4538 show basenames-may-differ
4539 Set whether a source file may have multiple base names.
4540 (A "base name" is the name of a file with the directory part removed.
4541 Example: The base name of "/home/user/hello.c" is "hello.c".)
4542 If set, GDB will canonicalize file names (e.g., expand symlinks)
4543 before comparing them. Canonicalization is an expensive operation,
4544 but it allows the same file be known by more than one base name.
4545 If not set (the default), all source files are assumed to have just
4546 one base name, and gdb will do file name comparisons more efficiently.
4552 Set a user name and notes for the current and any future trace runs.
4553 This is useful for long-running and/or disconnected traces, to
4554 inform others (or yourself) as to who is running the trace, supply
4555 contact information, or otherwise explain what is going on.
4557 set trace-stop-notes
4558 show trace-stop-notes
4559 Set a note attached to the trace run, that is displayed when the
4560 trace has been stopped by a tstop command. This is useful for
4561 instance as an explanation, if you are stopping a trace run that was
4562 started by someone else.
4564 * New remote packets
4568 Dynamically enable a tracepoint in a started trace experiment.
4572 Dynamically disable a tracepoint in a started trace experiment.
4576 Set the user and notes of the trace run.
4580 Query the current status of a tracepoint.
4584 Query the minimum length of instruction at which a fast tracepoint may
4587 * Dcache size (number of lines) and line-size are now runtime-configurable
4588 via "set dcache line" and "set dcache line-size" commands.
4592 Texas Instruments TMS320C6x tic6x-*-*
4596 Renesas RL78 rl78-*-elf
4598 *** Changes in GDB 7.3.1
4600 * The build failure for NetBSD and OpenBSD targets have now been fixed.
4602 *** Changes in GDB 7.3
4604 * GDB has a new command: "thread find [REGEXP]".
4605 It finds the thread id whose name, target id, or thread extra info
4606 matches the given regular expression.
4608 * The "catch syscall" command now works on mips*-linux* targets.
4610 * The -data-disassemble MI command now supports modes 2 and 3 for
4611 dumping the instruction opcodes.
4613 * New command line options
4615 -data-directory DIR Specify DIR as the "data-directory".
4616 This is mostly for testing purposes.
4618 * The "maint set python auto-load on|off" command has been renamed to
4619 "set auto-load-scripts on|off".
4621 * GDB has a new command: "set directories".
4622 It is like the "dir" command except that it replaces the
4623 source path list instead of augmenting it.
4625 * GDB now understands thread names.
4627 On GNU/Linux, "info threads" will display the thread name as set by
4628 prctl or pthread_setname_np.
4630 There is also a new command, "thread name", which can be used to
4631 assign a name internally for GDB to display.
4634 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
4635 has been integrated into GDB.
4639 ** The function gdb.Write now accepts an optional keyword 'stream'.
4640 This keyword, when provided, will direct the output to either
4641 stdout, stderr, or GDB's logging output.
4643 ** Parameters can now be be sub-classed in Python, and in particular
4644 you may implement the get_set_doc and get_show_doc functions.
4645 This improves how Parameter set/show documentation is processed
4646 and allows for more dynamic content.
4648 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
4649 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
4650 have an is_valid method.
4652 ** Breakpoints can now be sub-classed in Python, and in particular
4653 you may implement a 'stop' function that is executed each time
4654 the inferior reaches that breakpoint.
4656 ** New function gdb.lookup_global_symbol looks up a global symbol.
4658 ** GDB values in Python are now callable if the value represents a
4659 function. For example, if 'some_value' represents a function that
4660 takes two integer parameters and returns a value, you can call
4661 that function like so:
4663 result = some_value (10,20)
4665 ** Module gdb.types has been added.
4666 It contains a collection of utilities for working with gdb.Types objects:
4667 get_basic_type, has_field, make_enum_dict.
4669 ** Module gdb.printing has been added.
4670 It contains utilities for writing and registering pretty-printers.
4671 New classes: PrettyPrinter, SubPrettyPrinter,
4672 RegexpCollectionPrettyPrinter.
4673 New function: register_pretty_printer.
4675 ** New commands "info pretty-printers", "enable pretty-printer" and
4676 "disable pretty-printer" have been added.
4678 ** gdb.parameter("directories") is now available.
4680 ** New function gdb.newest_frame returns the newest frame in the
4683 ** The gdb.InferiorThread class has a new "name" attribute. This
4684 holds the thread's name.
4686 ** Python Support for Inferior events.
4687 Python scripts can add observers to be notified of events
4688 occurring in the process being debugged.
4689 The following events are currently supported:
4690 - gdb.events.cont Continue event.
4691 - gdb.events.exited Inferior exited event.
4692 - gdb.events.stop Signal received, and Breakpoint hit events.
4696 ** GDB now puts template parameters in scope when debugging in an
4697 instantiation. For example, if you have:
4699 template<int X> int func (void) { return X; }
4701 then if you step into func<5>, "print X" will show "5". This
4702 feature requires proper debuginfo support from the compiler; it
4703 was added to GCC 4.5.
4705 ** The motion commands "next", "finish", "until", and "advance" now
4706 work better when exceptions are thrown. In particular, GDB will
4707 no longer lose control of the inferior; instead, the GDB will
4708 stop the inferior at the point at which the exception is caught.
4709 This functionality requires a change in the exception handling
4710 code that was introduced in GCC 4.5.
4712 * GDB now follows GCC's rules on accessing volatile objects when
4713 reading or writing target state during expression evaluation.
4714 One notable difference to prior behavior is that "print x = 0"
4715 no longer generates a read of x; the value of the assignment is
4716 now always taken directly from the value being assigned.
4718 * GDB now has some support for using labels in the program's source in
4719 linespecs. For instance, you can use "advance label" to continue
4720 execution to a label.
4722 * GDB now has support for reading and writing a new .gdb_index
4723 section. This section holds a fast index of DWARF debugging
4724 information and can be used to greatly speed up GDB startup and
4725 operation. See the documentation for `save gdb-index' for details.
4727 * The "watch" command now accepts an optional "-location" argument.
4728 When used, this causes GDB to watch the memory referred to by the
4729 expression. Such a watchpoint is never deleted due to it going out
4732 * GDB now supports thread debugging of core dumps on GNU/Linux.
4734 GDB now activates thread debugging using the libthread_db library
4735 when debugging GNU/Linux core dumps, similarly to when debugging
4736 live processes. As a result, when debugging a core dump file, GDB
4737 is now able to display pthread_t ids of threads. For example, "info
4738 threads" shows the same output as when debugging the process when it
4739 was live. In earlier releases, you'd see something like this:
4742 * 1 LWP 6780 main () at main.c:10
4744 While now you see this:
4747 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
4749 It is also now possible to inspect TLS variables when debugging core
4752 When debugging a core dump generated on a machine other than the one
4753 used to run GDB, you may need to point GDB at the correct
4754 libthread_db library with the "set libthread-db-search-path"
4755 command. See the user manual for more details on this command.
4757 * When natively debugging programs on PowerPC BookE processors running
4758 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
4759 which stop execution of the inferior whenever it executes an instruction
4760 at any address within the specified range. See the "PowerPC Embedded"
4761 section in the user manual for more details.
4763 * New features in the GDB remote stub, GDBserver
4765 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
4766 and i686 LynxOS (version 5.x).
4768 ** GDBserver is now supported on Blackfin Linux.
4770 * New native configurations
4772 ia64 HP-UX ia64-*-hpux*
4776 Analog Devices, Inc. Blackfin Processor bfin-*
4778 * Ada task switching is now supported on sparc-elf targets when
4779 debugging a program using the Ravenscar Profile. For more information,
4780 see the "Tasking Support when using the Ravenscar Profile" section
4781 in the GDB user manual.
4783 * Guile support was removed.
4785 * New features in the GNU simulator
4787 ** The --map-info flag lists all known core mappings.
4789 ** CFI flashes may be simulated via the "cfi" device.
4791 *** Changes in GDB 7.2
4793 * Shared library support for remote targets by default
4795 When GDB is configured for a generic, non-OS specific target, like
4796 for example, --target=arm-eabi or one of the many *-*-elf targets,
4797 GDB now queries remote stubs for loaded shared libraries using the
4798 `qXfer:libraries:read' packet. Previously, shared library support
4799 was always disabled for such configurations.
4803 ** Argument Dependent Lookup (ADL)
4805 In C++ ADL lookup directs function search to the namespaces of its
4806 arguments even if the namespace has not been imported.
4816 Here the compiler will search for `foo' in the namespace of 'b'
4817 and find A::foo. GDB now supports this. This construct is commonly
4818 used in the Standard Template Library for operators.
4820 ** Improved User Defined Operator Support
4822 In addition to member operators, GDB now supports lookup of operators
4823 defined in a namespace and imported with a `using' directive, operators
4824 defined in the global scope, operators imported implicitly from an
4825 anonymous namespace, and the ADL operators mentioned in the previous
4827 GDB now also supports proper overload resolution for all the previously
4828 mentioned flavors of operators.
4830 ** static const class members
4832 Printing of static const class members that are initialized in the
4833 class definition has been fixed.
4835 * Windows Thread Information Block access.
4837 On Windows targets, GDB now supports displaying the Windows Thread
4838 Information Block (TIB) structure. This structure is visible either
4839 by using the new command `info w32 thread-information-block' or, by
4840 dereferencing the new convenience variable named `$_tlb', a
4841 thread-specific pointer to the TIB. This feature is also supported
4842 when remote debugging using GDBserver.
4844 * Static tracepoints
4846 Static tracepoints are calls in the user program into a tracing
4847 library. One such library is a port of the LTTng kernel tracer to
4848 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
4849 When debugging with GDBserver, GDB now supports combining the GDB
4850 tracepoint machinery with such libraries. For example: the user can
4851 use GDB to probe a static tracepoint marker (a call from the user
4852 program into the tracing library) with the new "strace" command (see
4853 "New commands" below). This creates a "static tracepoint" in the
4854 breakpoint list, that can be manipulated with the same feature set
4855 as fast and regular tracepoints. E.g., collect registers, local and
4856 global variables, collect trace state variables, and define
4857 tracepoint conditions. In addition, the user can collect extra
4858 static tracepoint marker specific data, by collecting the new
4859 $_sdata internal variable. When analyzing the trace buffer, you can
4860 inspect $_sdata like any other variable available to GDB. For more
4861 information, see the "Tracepoints" chapter in GDB user manual. New
4862 remote packets have been defined to support static tracepoints, see
4863 the "New remote packets" section below.
4865 * Better reconstruction of tracepoints after disconnected tracing
4867 GDB will attempt to download the original source form of tracepoint
4868 definitions when starting a trace run, and then will upload these
4869 upon reconnection to the target, resulting in a more accurate
4870 reconstruction of the tracepoints that are in use on the target.
4874 You can now exercise direct control over the ways that GDB can
4875 affect your program. For instance, you can disallow the setting of
4876 breakpoints, so that the program can run continuously (assuming
4877 non-stop mode). In addition, the "observer" variable is available
4878 to switch all of the different controls; in observer mode, GDB
4879 cannot affect the target's behavior at all, which is useful for
4880 tasks like diagnosing live systems in the field.
4882 * The new convenience variable $_thread holds the number of the
4885 * New remote packets
4889 Return the address of the Windows Thread Information Block of a given thread.
4893 In response to several of the tracepoint packets, the target may now
4894 also respond with a number of intermediate `qRelocInsn' request
4895 packets before the final result packet, to have GDB handle
4896 relocating an instruction to execute at a different address. This
4897 is particularly useful for stubs that support fast tracepoints. GDB
4898 reports support for this feature in the qSupported packet.
4902 List static tracepoint markers in the target program.
4906 List static tracepoint markers at a given address in the target
4909 qXfer:statictrace:read
4911 Read the static trace data collected (by a `collect $_sdata'
4912 tracepoint action). The remote stub reports support for this packet
4913 to gdb's qSupported query.
4917 Send the current settings of GDB's permission flags.
4921 Send part of the source (textual) form of a tracepoint definition,
4922 which includes location, conditional, and action list.
4924 * The source command now accepts a -s option to force searching for the
4925 script in the source search path even if the script name specifies
4928 * New features in the GDB remote stub, GDBserver
4930 - GDBserver now support tracepoints (including fast tracepoints, and
4931 static tracepoints). The feature is currently supported by the
4932 i386-linux and amd64-linux builds. See the "Tracepoints support
4933 in gdbserver" section in the manual for more information.
4935 GDBserver JIT compiles the tracepoint's conditional agent
4936 expression bytecode into native code whenever possible for low
4937 overhead dynamic tracepoints conditionals. For such tracepoints,
4938 an expression that examines program state is evaluated when the
4939 tracepoint is reached, in order to determine whether to capture
4940 trace data. If the condition is simple and false, processing the
4941 tracepoint finishes very quickly and no data is gathered.
4943 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
4944 for static tracepoints support.
4946 - GDBserver now supports x86_64 Windows 64-bit debugging.
4948 * GDB now sends xmlRegisters= in qSupported packet to indicate that
4949 it understands register description.
4951 * The --batch flag now disables pagination and queries.
4953 * X86 general purpose registers
4955 GDB now supports reading/writing byte, word and double-word x86
4956 general purpose registers directly. This means you can use, say,
4957 $ah or $ax to refer, respectively, to the byte register AH and
4958 16-bit word register AX that are actually portions of the 32-bit
4959 register EAX or 64-bit register RAX.
4961 * The `commands' command now accepts a range of breakpoints to modify.
4962 A plain `commands' following a command that creates multiple
4963 breakpoints affects all the breakpoints set by that command. This
4964 applies to breakpoints set by `rbreak', and also applies when a
4965 single `break' command creates multiple breakpoints (e.g.,
4966 breakpoints on overloaded c++ functions).
4968 * The `rbreak' command now accepts a filename specification as part of
4969 its argument, limiting the functions selected by the regex to those
4970 in the specified file.
4972 * Support for remote debugging Windows and SymbianOS shared libraries
4973 from Unix hosts has been improved. Non Windows GDB builds now can
4974 understand target reported file names that follow MS-DOS based file
4975 system semantics, such as file names that include drive letters and
4976 use the backslash character as directory separator. This makes it
4977 possible to transparently use the "set sysroot" and "set
4978 solib-search-path" on Unix hosts to point as host copies of the
4979 target's shared libraries. See the new command "set
4980 target-file-system-kind" described below, and the "Commands to
4981 specify files" section in the user manual for more information.
4985 eval template, expressions...
4986 Convert the values of one or more expressions under the control
4987 of the string template to a command line, and call it.
4989 set target-file-system-kind unix|dos-based|auto
4990 show target-file-system-kind
4991 Set or show the assumed file system kind for target reported file
4994 save breakpoints <filename>
4995 Save all current breakpoint definitions to a file suitable for use
4996 in a later debugging session. To read the saved breakpoint
4997 definitions, use the `source' command.
4999 `save tracepoints' is a new alias for `save-tracepoints'. The latter
5002 info static-tracepoint-markers
5003 Display information about static tracepoint markers in the target.
5005 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
5006 Define a static tracepoint by probing a marker at the given
5007 function, line, address, or marker ID.
5011 Enable and disable observer mode.
5013 set may-write-registers on|off
5014 set may-write-memory on|off
5015 set may-insert-breakpoints on|off
5016 set may-insert-tracepoints on|off
5017 set may-insert-fast-tracepoints on|off
5018 set may-interrupt on|off
5019 Set individual permissions for GDB effects on the target. Note that
5020 some of these settings can have undesirable or surprising
5021 consequences, particularly when changed in the middle of a session.
5022 For instance, disabling the writing of memory can prevent
5023 breakpoints from being inserted, cause single-stepping to fail, or
5024 even crash your program, if you disable after breakpoints have been
5025 inserted. However, GDB should not crash.
5027 set record memory-query on|off
5028 show record memory-query
5029 Control whether to stop the inferior if memory changes caused
5030 by an instruction cannot be recorded.
5035 The disassemble command now supports "start,+length" form of two arguments.
5039 ** GDB now provides a new directory location, called the python directory,
5040 where Python scripts written for GDB can be installed. The location
5041 of that directory is <data-directory>/python, where <data-directory>
5042 is the GDB data directory. For more details, see section `Scripting
5043 GDB using Python' in the manual.
5045 ** The GDB Python API now has access to breakpoints, symbols, symbol
5046 tables, program spaces, inferiors, threads and frame's code blocks.
5047 Additionally, GDB Parameters can now be created from the API, and
5048 manipulated via set/show in the CLI.
5050 ** New functions gdb.target_charset, gdb.target_wide_charset,
5051 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
5053 ** New exception gdb.GdbError.
5055 ** Pretty-printers are now also looked up in the current program space.
5057 ** Pretty-printers can now be individually enabled and disabled.
5059 ** GDB now looks for names of Python scripts to auto-load in a
5060 special section named `.debug_gdb_scripts', in addition to looking
5061 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
5063 * Tracepoint actions were unified with breakpoint commands. In particular,
5064 there are no longer differences in "info break" output for breakpoints and
5065 tracepoints and the "commands" command can be used for both tracepoints and
5066 regular breakpoints.
5070 ARM Symbian arm*-*-symbianelf*
5072 * D language support.
5073 GDB now supports debugging programs written in the D programming
5076 * GDB now supports the extended ptrace interface for PowerPC which is
5077 available since Linux kernel version 2.6.34. This automatically enables
5078 any hardware breakpoints and additional hardware watchpoints available in
5079 the processor. The old ptrace interface exposes just one hardware
5080 watchpoint and no hardware breakpoints.
5082 * GDB is now able to use the Data Value Compare (DVC) register available on
5083 embedded PowerPC processors to implement in hardware simple watchpoint
5084 conditions of the form:
5086 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
5088 This works in native GDB running on Linux kernels with the extended ptrace
5089 interface mentioned above.
5091 *** Changes in GDB 7.1
5095 ** Namespace Support
5097 GDB now supports importing of namespaces in C++. This enables the
5098 user to inspect variables from imported namespaces. Support for
5099 namepace aliasing has also been added. So, if a namespace is
5100 aliased in the current scope (e.g. namepace C=A; ) the user can
5101 print variables using the alias (e.g. (gdb) print C::x).
5105 All known bugs relating to the printing of virtual base class were
5106 fixed. It is now possible to call overloaded static methods using a
5111 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
5112 and reinterpret_cast<> are now handled by the C++ expression parser.
5116 Xilinx MicroBlaze microblaze-*-*
5121 Xilinx MicroBlaze microblaze
5124 * Multi-program debugging.
5126 GDB now has support for multi-program (a.k.a. multi-executable or
5127 multi-exec) debugging. This allows for debugging multiple inferiors
5128 simultaneously each running a different program under the same GDB
5129 session. See "Debugging Multiple Inferiors and Programs" in the
5130 manual for more information. This implied some user visible changes
5131 in the multi-inferior support. For example, "info inferiors" now
5132 lists inferiors that are not running yet or that have exited
5133 already. See also "New commands" and "New options" below.
5135 * New tracing features
5137 GDB's tracepoint facility now includes several new features:
5139 ** Trace state variables
5141 GDB tracepoints now include support for trace state variables, which
5142 are variables managed by the target agent during a tracing
5143 experiment. They are useful for tracepoints that trigger each
5144 other, so for instance one tracepoint can count hits in a variable,
5145 and then a second tracepoint has a condition that is true when the
5146 count reaches a particular value. Trace state variables share the
5147 $-syntax of GDB convenience variables, and can appear in both
5148 tracepoint actions and condition expressions. Use the "tvariable"
5149 command to create, and "info tvariables" to view; see "Trace State
5150 Variables" in the manual for more detail.
5154 GDB now includes an option for defining fast tracepoints, which
5155 targets may implement more efficiently, such as by installing a jump
5156 into the target agent rather than a trap instruction. The resulting
5157 speedup can be by two orders of magnitude or more, although the
5158 tradeoff is that some program locations on some target architectures
5159 might not allow fast tracepoint installation, for instance if the
5160 instruction to be replaced is shorter than the jump. To request a
5161 fast tracepoint, use the "ftrace" command, with syntax identical to
5162 the regular trace command.
5164 ** Disconnected tracing
5166 It is now possible to detach GDB from the target while it is running
5167 a trace experiment, then reconnect later to see how the experiment
5168 is going. In addition, a new variable disconnected-tracing lets you
5169 tell the target agent whether to continue running a trace if the
5170 connection is lost unexpectedly.
5174 GDB now has the ability to save the trace buffer into a file, and
5175 then use that file as a target, similarly to you can do with
5176 corefiles. You can select trace frames, print data that was
5177 collected in them, and use tstatus to display the state of the
5178 tracing run at the moment that it was saved. To create a trace
5179 file, use "tsave <filename>", and to use it, do "target tfile
5182 ** Circular trace buffer
5184 You can ask the target agent to handle the trace buffer as a
5185 circular buffer, discarding the oldest trace frames to make room for
5186 newer ones, by setting circular-trace-buffer to on. This feature may
5187 not be available for all target agents.
5192 The disassemble command, when invoked with two arguments, now requires
5193 the arguments to be comma-separated.
5196 The info variables command now displays variable definitions. Files
5197 which only declare a variable are not shown.
5200 The source command is now capable of sourcing Python scripts.
5201 This feature is dependent on the debugger being build with Python
5204 Related to this enhancement is also the introduction of a new command
5205 "set script-extension" (see below).
5207 * New commands (for set/show, see "New options" below)
5209 record save [<FILENAME>]
5210 Save a file (in core file format) containing the process record
5211 execution log for replay debugging at a later time.
5213 record restore <FILENAME>
5214 Restore the process record execution log that was saved at an
5215 earlier time, for replay debugging.
5217 add-inferior [-copies <N>] [-exec <FILENAME>]
5220 clone-inferior [-copies <N>] [ID]
5221 Make a new inferior ready to execute the same program another
5222 inferior has loaded.
5227 maint info program-spaces
5228 List the program spaces loaded into GDB.
5230 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
5231 show remote interrupt-sequence
5232 Allow the user to select one of ^C, a BREAK signal or BREAK-g
5233 as the sequence to the remote target in order to interrupt the execution.
5234 Ctrl-C is a default. Some system prefers BREAK which is high level of
5235 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
5236 Magic SysRq g. It is BREAK signal and character 'g'.
5238 set remote interrupt-on-connect [on | off]
5239 show remote interrupt-on-connect
5240 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
5241 remote target when gdb connects to it. This is needed when you debug
5244 set remotebreak [on | off]
5246 Deprecated. Use "set/show remote interrupt-sequence" instead.
5248 tvariable $NAME [ = EXP ]
5249 Create or modify a trace state variable.
5252 List trace state variables and their values.
5254 delete tvariable $NAME ...
5255 Delete one or more trace state variables.
5258 Evaluate the given expressions without collecting anything into the
5259 trace buffer. (Valid in tracepoint actions only.)
5261 ftrace FN / FILE:LINE / *ADDR
5262 Define a fast tracepoint at the given function, line, or address.
5264 * New expression syntax
5266 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
5267 GDB now parses 0b101010 identically with 42.
5271 set follow-exec-mode new|same
5272 show follow-exec-mode
5273 Control whether GDB reuses the same inferior across an exec call or
5274 creates a new one. This is useful to be able to restart the old
5275 executable after the inferior having done an exec call.
5277 set default-collect EXPR, ...
5278 show default-collect
5279 Define a list of expressions to be collected at each tracepoint.
5280 This is a useful way to ensure essential items are not overlooked,
5281 such as registers or a critical global variable.
5283 set disconnected-tracing
5284 show disconnected-tracing
5285 If set to 1, the target is instructed to continue tracing if it
5286 loses its connection to GDB. If 0, the target is to stop tracing
5289 set circular-trace-buffer
5290 show circular-trace-buffer
5291 If set to on, the target is instructed to use a circular trace buffer
5292 and discard the oldest trace frames instead of stopping the trace due
5293 to a full trace buffer. If set to off, the trace stops when the buffer
5294 fills up. Some targets may not support this.
5296 set script-extension off|soft|strict
5297 show script-extension
5298 If set to "off", the debugger does not perform any script language
5299 recognition, and all sourced files are assumed to be GDB scripts.
5300 If set to "soft" (the default), files are sourced according to
5301 filename extension, falling back to GDB scripts if the first
5303 If set to "strict", files are sourced according to filename extension.
5305 set ada trust-PAD-over-XVS on|off
5306 show ada trust-PAD-over-XVS
5307 If off, activate a workaround against a bug in the debugging information
5308 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
5309 the GCC sources for more information about the GNAT encoding and
5310 PAD types in particular). It is always safe to set this option to
5311 off, but this introduces a slight performance penalty. The default
5314 * Python API Improvements
5316 ** GDB provides the new class gdb.LazyString. This is useful in
5317 some pretty-printing cases. The new method gdb.Value.lazy_string
5318 provides a simple way to create objects of this type.
5320 ** The fields returned by gdb.Type.fields now have an
5321 `is_base_class' attribute.
5323 ** The new method gdb.Type.range returns the range of an array type.
5325 ** The new method gdb.parse_and_eval can be used to parse and
5326 evaluate an expression.
5328 * New remote packets
5331 Define a trace state variable.
5334 Get the current value of a trace state variable.
5337 Set desired tracing behavior upon disconnection.
5340 Set the trace buffer to be linear or circular.
5343 Get data about the tracepoints currently in use.
5347 Process record now works correctly with hardware watchpoints.
5349 Multiple bug fixes have been made to the mips-irix port, making it
5350 much more reliable. In particular:
5351 - Debugging threaded applications is now possible again. Previously,
5352 GDB would hang while starting the program, or while waiting for
5353 the program to stop at a breakpoint.
5354 - Attaching to a running process no longer hangs.
5355 - An error occurring while loading a core file has been fixed.
5356 - Changing the value of the PC register now works again. This fixes
5357 problems observed when using the "jump" command, or when calling
5358 a function from GDB, or even when assigning a new value to $pc.
5359 - With the "finish" and "return" commands, the return value for functions
5360 returning a small array is now correctly printed.
5361 - It is now possible to break on shared library code which gets executed
5362 during a shared library init phase (code executed while executing
5363 their .init section). Previously, the breakpoint would have no effect.
5364 - GDB is now able to backtrace through the signal handler for
5365 non-threaded programs.
5367 PIE (Position Independent Executable) programs debugging is now supported.
5368 This includes debugging execution of PIC (Position Independent Code) shared
5369 libraries although for that, it should be possible to run such libraries as an
5372 *** Changes in GDB 7.0
5374 * GDB now has an interface for JIT compilation. Applications that
5375 dynamically generate code can create symbol files in memory and register
5376 them with GDB. For users, the feature should work transparently, and
5377 for JIT developers, the interface is documented in the GDB manual in the
5378 "JIT Compilation Interface" chapter.
5380 * Tracepoints may now be conditional. The syntax is as for
5381 breakpoints; either an "if" clause appended to the "trace" command,
5382 or the "condition" command is available. GDB sends the condition to
5383 the target for evaluation using the same bytecode format as is used
5384 for tracepoint actions.
5386 * The disassemble command now supports: an optional /r modifier, print the
5387 raw instructions in hex as well as in symbolic form, and an optional /m
5388 modifier to print mixed source+assembly.
5390 * Process record and replay
5392 In a architecture environment that supports ``process record and
5393 replay'', ``process record and replay'' target can record a log of
5394 the process execution, and replay it with both forward and reverse
5397 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
5398 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
5399 set execution-direction {forward|reverse}, for targets that support
5402 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
5403 feature is available with a native GDB running on kernel version
5406 * GDB now has support for multi-byte and wide character sets on the
5407 target. Strings whose character type is wchar_t, char16_t, or
5408 char32_t are now correctly printed. GDB supports wide- and unicode-
5409 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
5410 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
5411 `printf'. This feature requires iconv to work properly; if your
5412 system does not have a working iconv, GDB can use GNU libiconv. See
5413 the installation instructions for more information.
5415 * GDB now supports automatic retrieval of shared library files from
5416 remote targets. To use this feature, specify a system root that begins
5417 with the `remote:' prefix, either via the `set sysroot' command or via
5418 the `--with-sysroot' configure-time option.
5420 * "info sharedlibrary" now takes an optional regex of libraries to show,
5421 and it now reports if a shared library has no debugging information.
5423 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
5424 now complete on file names.
5426 * When completing in expressions, gdb will attempt to limit
5427 completions to allowable structure or union fields, where appropriate.
5428 For instance, consider:
5430 # struct example { int f1; double f2; };
5431 # struct example variable;
5434 If the user types TAB at the end of this command line, the available
5435 completions will be "f1" and "f2".
5437 * Inlined functions are now supported. They show up in backtraces, and
5438 the "step", "next", and "finish" commands handle them automatically.
5440 * GDB now supports the token-splicing (##) and stringification (#)
5441 operators when expanding macros. It also supports variable-arity
5444 * GDB now supports inspecting extra signal information, exported by
5445 the new $_siginfo convenience variable. The feature is currently
5446 implemented on linux ARM, i386 and amd64.
5448 * GDB can now display the VFP floating point registers and NEON vector
5449 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
5450 can provide these registers (requires Linux 2.6.30 or later). Remote
5451 and simulator targets may also provide them.
5453 * New remote packets
5456 Search memory for a sequence of bytes.
5459 Turn off `+'/`-' protocol acknowledgments to permit more efficient
5460 operation over reliable transport links. Use of this packet is
5461 controlled by the `set remote noack-packet' command.
5464 Kill the process with the specified process ID. Use this in preference
5465 to `k' when multiprocess protocol extensions are supported.
5468 Obtains additional operating system information
5472 Read or write additional signal information.
5474 * Removed remote protocol undocumented extension
5476 An undocumented extension to the remote protocol's `S' stop reply
5477 packet that permitted the stub to pass a process id was removed.
5478 Remote servers should use the `T' stop reply packet instead.
5480 * GDB now supports multiple function calling conventions according to the
5481 DWARF-2 DW_AT_calling_convention function attribute.
5483 * The SH target utilizes the aforementioned change to distinguish between gcc
5484 and Renesas calling convention. It also adds the new CLI commands
5485 `set/show sh calling-convention'.
5487 * GDB can now read compressed debug sections, as produced by GNU gold
5488 with the --compress-debug-sections=zlib flag.
5490 * 64-bit core files are now supported on AIX.
5492 * Thread switching is now supported on Tru64.
5494 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
5495 which will be allocated using malloc later in program execution.
5497 * The qXfer:libraries:read remote protocol packet now allows passing a
5498 list of section offsets.
5500 * On GNU/Linux, GDB can now attach to stopped processes. Several race
5501 conditions handling signals delivered during attach or thread creation
5502 have also been fixed.
5504 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
5505 From the user's standpoint, all unqualified instances of True and False
5506 are treated as the standard definitions, regardless of context.
5508 * GDB now parses C++ symbol and type names more flexibly. For
5511 template<typename T> class C { };
5514 GDB will now correctly handle all of:
5516 ptype C<char const *>
5517 ptype C<char const*>
5518 ptype C<const char *>
5519 ptype C<const char*>
5521 * New features in the GDB remote stub, gdbserver
5523 - The "--wrapper" command-line argument tells gdbserver to use a
5524 wrapper program to launch programs for debugging.
5526 - On PowerPC and S/390 targets, it is now possible to use a single
5527 gdbserver executable to debug both 32-bit and 64-bit programs.
5528 (This requires gdbserver itself to be built as a 64-bit executable.)
5530 - gdbserver uses the new noack protocol mode for TCP connections to
5531 reduce communications latency, if also supported and enabled in GDB.
5533 - Support for the sparc64-linux-gnu target is now included in
5536 - The amd64-linux build of gdbserver now supports debugging both
5537 32-bit and 64-bit programs.
5539 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
5540 now support hardware watchpoints, and will use them automatically
5545 GDB now has support for scripting using Python. Whether this is
5546 available is determined at configure time.
5548 New GDB commands can now be written in Python.
5550 * Ada tasking support
5552 Ada tasks can now be inspected in GDB. The following commands have
5556 Print the list of Ada tasks.
5558 Print detailed information about task number N.
5560 Print the task number of the current task.
5562 Switch the context of debugging to task number N.
5564 * Support for user-defined prefixed commands. The "define" command can
5565 add new commands to existing prefixes, e.g. "target".
5567 * Multi-inferior, multi-process debugging.
5569 GDB now has generalized support for multi-inferior debugging. See
5570 "Debugging Multiple Inferiors" in the manual for more information.
5571 Although availability still depends on target support, the command
5572 set is more uniform now. The GNU/Linux specific multi-forks support
5573 has been migrated to this new framework. This implied some user
5574 visible changes; see "New commands" and also "Removed commands"
5577 * Target descriptions can now describe the target OS ABI. See the
5578 "Target Description Format" section in the user manual for more
5581 * Target descriptions can now describe "compatible" architectures
5582 to indicate that the target can execute applications for a different
5583 architecture in addition to those for the main target architecture.
5584 See the "Target Description Format" section in the user manual for
5587 * Multi-architecture debugging.
5589 GDB now includes general supports for debugging applications on
5590 hybrid systems that use more than one single processor architecture
5591 at the same time. Each such hybrid architecture still requires
5592 specific support to be added. The only hybrid architecture supported
5593 in this version of GDB is the Cell Broadband Engine.
5595 * GDB now supports integrated debugging of Cell/B.E. applications that
5596 use both the PPU and SPU architectures. To enable support for hybrid
5597 Cell/B.E. debugging, you need to configure GDB to support both the
5598 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
5599 --enable-targets configure option.
5601 * Non-stop mode debugging.
5603 For some targets, GDB now supports an optional mode of operation in
5604 which you can examine stopped threads while other threads continue
5605 to execute freely. This is referred to as non-stop mode, with the
5606 old mode referred to as all-stop mode. See the "Non-Stop Mode"
5607 section in the user manual for more information.
5609 To be able to support remote non-stop debugging, a remote stub needs
5610 to implement the non-stop mode remote protocol extensions, as
5611 described in the "Remote Non-Stop" section of the user manual. The
5612 GDB remote stub, gdbserver, has been adjusted to support these
5613 extensions on linux targets.
5615 * New commands (for set/show, see "New options" below)
5617 catch syscall [NAME(S) | NUMBER(S)]
5618 Catch system calls. Arguments, which should be names of system
5619 calls or their numbers, mean catch only those syscalls. Without
5620 arguments, every syscall will be caught. When the inferior issues
5621 any of the specified syscalls, GDB will stop and announce the system
5622 call, both when it is called and when its call returns. This
5623 feature is currently available with a native GDB running on the
5624 Linux Kernel, under the following architectures: x86, x86_64,
5625 PowerPC and PowerPC64.
5627 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
5629 Search memory for a sequence of bytes.
5631 maint set python print-stack
5632 maint show python print-stack
5633 Show a stack trace when an error is encountered in a Python script.
5636 Invoke CODE by passing it to the Python interpreter.
5641 These allow macros to be defined, undefined, and listed
5645 Show operating system information about processes.
5648 List the inferiors currently under GDB's control.
5651 Switch focus to inferior number NUM.
5654 Detach from inferior number NUM.
5657 Kill inferior number NUM.
5661 set spu stop-on-load
5662 show spu stop-on-load
5663 Control whether to stop for new SPE threads during Cell/B.E. debugging.
5665 set spu auto-flush-cache
5666 show spu auto-flush-cache
5667 Control whether to automatically flush the software-managed cache
5668 during Cell/B.E. debugging.
5670 set sh calling-convention
5671 show sh calling-convention
5672 Control the calling convention used when calling SH target functions.
5675 show debug timestamp
5676 Control display of timestamps with GDB debugging output.
5678 set disassemble-next-line
5679 show disassemble-next-line
5680 Control display of disassembled source lines or instructions when
5683 set remote noack-packet
5684 show remote noack-packet
5685 Set/show the use of remote protocol QStartNoAckMode packet. See above
5686 under "New remote packets."
5688 set remote query-attached-packet
5689 show remote query-attached-packet
5690 Control use of remote protocol `qAttached' (query-attached) packet.
5692 set remote read-siginfo-object
5693 show remote read-siginfo-object
5694 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
5697 set remote write-siginfo-object
5698 show remote write-siginfo-object
5699 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
5702 set remote reverse-continue
5703 show remote reverse-continue
5704 Control use of remote protocol 'bc' (reverse-continue) packet.
5706 set remote reverse-step
5707 show remote reverse-step
5708 Control use of remote protocol 'bs' (reverse-step) packet.
5710 set displaced-stepping
5711 show displaced-stepping
5712 Control displaced stepping mode. Displaced stepping is a way to
5713 single-step over breakpoints without removing them from the debuggee.
5714 Also known as "out-of-line single-stepping".
5717 show debug displaced
5718 Control display of debugging info for displaced stepping.
5720 maint set internal-error
5721 maint show internal-error
5722 Control what GDB does when an internal error is detected.
5724 maint set internal-warning
5725 maint show internal-warning
5726 Control what GDB does when an internal warning is detected.
5731 Use a wrapper program to launch programs for debugging.
5733 set multiple-symbols (all|ask|cancel)
5734 show multiple-symbols
5735 The value of this variable can be changed to adjust the debugger behavior
5736 when an expression or a breakpoint location contains an ambiguous symbol
5737 name (an overloaded function name, for instance).
5739 set breakpoint always-inserted
5740 show breakpoint always-inserted
5741 Keep breakpoints always inserted in the target, as opposed to inserting
5742 them when resuming the target, and removing them when the target stops.
5743 This option can improve debugger performance on slow remote targets.
5745 set arm fallback-mode (arm|thumb|auto)
5746 show arm fallback-mode
5747 set arm force-mode (arm|thumb|auto)
5749 These commands control how ARM GDB determines whether instructions
5750 are ARM or Thumb. The default for both settings is auto, which uses
5751 the current CPSR value for instructions without symbols; previous
5752 versions of GDB behaved as if "set arm fallback-mode arm".
5754 set arm unwind-secure-frames
5755 Enable unwinding from Non-secure to Secure mode on Cortex-M with
5757 This can trigger security exceptions when unwinding exception stacks.
5759 set disable-randomization
5760 show disable-randomization
5761 Standalone programs run with the virtual address space randomization enabled
5762 by default on some platforms. This option keeps the addresses stable across
5763 multiple debugging sessions.
5767 Control whether other threads are stopped or not when some thread hits
5772 Requests that asynchronous execution is enabled in the target, if available.
5773 In this case, it's possible to resume target in the background, and interact
5774 with GDB while the target is running. "show target-async" displays the
5775 current state of asynchronous execution of the target.
5777 set target-wide-charset
5778 show target-wide-charset
5779 The target-wide-charset is the name of the character set that GDB
5780 uses when printing characters whose type is wchar_t.
5782 set tcp auto-retry (on|off)
5784 set tcp connect-timeout
5785 show tcp connect-timeout
5786 These commands allow GDB to retry failed TCP connections to a remote stub
5787 with a specified timeout period; this is useful if the stub is launched
5788 in parallel with GDB but may not be ready to accept connections immediately.
5790 set libthread-db-search-path
5791 show libthread-db-search-path
5792 Control list of directories which GDB will search for appropriate
5795 set schedule-multiple (on|off)
5796 show schedule-multiple
5797 Allow GDB to resume all threads of all processes or only threads of
5798 the current process.
5802 Use more aggressive caching for accesses to the stack. This improves
5803 performance of remote debugging (particularly backtraces) without
5804 affecting correctness.
5806 set interactive-mode (on|off|auto)
5807 show interactive-mode
5808 Control whether GDB runs in interactive mode (on) or not (off).
5809 When in interactive mode, GDB waits for the user to answer all
5810 queries. Otherwise, GDB does not wait and assumes the default
5811 answer. When set to auto (the default), GDB determines which
5812 mode to use based on the stdin settings.
5817 For program forks, this is replaced by the new more generic `info
5818 inferiors' command. To list checkpoints, you can still use the
5819 `info checkpoints' command, which was an alias for the `info forks'
5823 Replaced by the new `inferior' command. To switch between
5824 checkpoints, you can still use the `restart' command, which was an
5825 alias for the `fork' command.
5828 This is removed, since some targets don't have a notion of
5829 processes. To switch between processes, you can still use the
5830 `inferior' command using GDB's own inferior number.
5833 For program forks, this is replaced by the new more generic `kill
5834 inferior' command. To delete a checkpoint, you can still use the
5835 `delete checkpoint' command, which was an alias for the `delete
5839 For program forks, this is replaced by the new more generic `detach
5840 inferior' command. To detach a checkpoint, you can still use the
5841 `detach checkpoint' command, which was an alias for the `detach
5844 * New native configurations
5846 x86/x86_64 Darwin i[34567]86-*-darwin*
5848 x86_64 MinGW x86_64-*-mingw*
5852 Lattice Mico32 lm32-*
5853 x86 DICOS i[34567]86-*-dicos*
5854 x86_64 DICOS x86_64-*-dicos*
5857 * The GDB remote stub, gdbserver, now supports x86 Windows CE
5858 (mingw32ce) debugging.
5864 These commands were actually not implemented on any target.
5866 *** Changes in GDB 6.8
5868 * New native configurations
5870 NetBSD/hppa hppa*-*netbsd*
5871 Xtensa GNU/Linux xtensa*-*-linux*
5875 NetBSD/hppa hppa*-*-netbsd*
5876 Xtensa GNU/Linux xtensa*-*-linux*
5878 * Change in command line behavior -- corefiles vs. process ids.
5880 When the '-p NUMBER' or '--pid NUMBER' options are used, and
5881 attaching to process NUMBER fails, GDB no longer attempts to open a
5882 core file named NUMBER. Attaching to a program using the -c option
5883 is no longer supported. Instead, use the '-p' or '--pid' options.
5885 * GDB can now be built as a native debugger for debugging Windows x86
5886 (mingw32) Portable Executable (PE) programs.
5888 * Pending breakpoints no longer change their number when their address
5891 * GDB now supports breakpoints with multiple locations,
5892 including breakpoints on C++ constructors, inside C++ templates,
5893 and in inlined functions.
5895 * GDB's ability to debug optimized code has been improved. GDB more
5896 accurately identifies function bodies and lexical blocks that occupy
5897 more than one contiguous range of addresses.
5899 * Target descriptions can now describe registers for PowerPC.
5901 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
5902 registers on PowerPC targets.
5904 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
5905 targets even when the libthread_db library is not available.
5907 * The GDB remote stub, gdbserver, now supports the new file transfer
5908 commands (remote put, remote get, and remote delete).
5910 * The GDB remote stub, gdbserver, now supports run and attach in
5911 extended-remote mode.
5913 * hppa*64*-*-hpux11* target broken
5914 The debugger is unable to start a program and fails with the following
5915 error: "Error trying to get information about dynamic linker".
5916 The gdb-6.7 release is also affected.
5918 * GDB now supports the --enable-targets= configure option to allow
5919 building a single GDB executable that supports multiple remote
5920 target architectures.
5922 * GDB now supports debugging C and C++ programs which use the
5923 Decimal Floating Point extension. In addition, the PowerPC target
5924 now has a set of pseudo-registers to inspect decimal float values
5925 stored in two consecutive float registers.
5927 * The -break-insert MI command can optionally create pending
5930 * Improved support for debugging Ada
5931 Many improvements to the Ada language support have been made. These
5933 - Better support for Ada2005 interface types
5934 - Improved handling of arrays and slices in general
5935 - Better support for Taft-amendment types
5936 - The '{type} ADDRESS' expression is now allowed on the left hand-side
5938 - Improved command completion in Ada
5941 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
5946 set print frame-arguments (all|scalars|none)
5947 show print frame-arguments
5948 The value of this variable can be changed to control which argument
5949 values should be printed by the debugger when displaying a frame.
5954 Transfer files to and from a remote target, and delete remote files.
5961 Transfer files to and from a remote target, and delete remote files.
5963 * New remote packets
5970 Open, close, read, write, and delete files on the remote system.
5973 Attach to an existing process on the remote system, in extended-remote
5977 Run a new process on the remote system, in extended-remote mode.
5979 *** Changes in GDB 6.7
5981 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
5982 bfd, libiberty and opcodes, as revealed by static analysis donated by
5983 Coverity, Inc. (http://scan.coverity.com).
5985 * When looking up multiply-defined global symbols, GDB will now prefer the
5986 symbol definition in the current shared library if it was built using the
5987 -Bsymbolic linker option.
5989 * When the Text User Interface (TUI) is not configured, GDB will now
5990 recognize the -tui command-line option and print a message that the TUI
5993 * The GDB remote stub, gdbserver, now has lower overhead for high
5994 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
5996 * GDB for MIPS targets now autodetects whether a remote target provides
5997 32-bit or 64-bit register values.
5999 * Support for C++ member pointers has been improved.
6001 * GDB now understands XML target descriptions, which specify the
6002 target's overall architecture. GDB can read a description from
6003 a local file or over the remote serial protocol.
6005 * Vectors of single-byte data use a new integer type which is not
6006 automatically displayed as character or string data.
6008 * The /s format now works with the print command. It displays
6009 arrays of single-byte integers and pointers to single-byte integers
6012 * Target descriptions can now describe target-specific registers,
6013 for architectures which have implemented the support (currently
6014 only ARM, M68K, and MIPS).
6016 * GDB and the GDB remote stub, gdbserver, now support the XScale
6019 * The GDB remote stub, gdbserver, has been updated to support
6020 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
6021 has been rewritten to use the standard GDB remote protocol.
6023 * GDB can now step into C++ functions which are called through thunks.
6025 * GDB for the Cell/B.E. SPU now supports overlay debugging.
6027 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
6028 layout. It also supports a TextSeg= and DataSeg= response when only
6029 segment base addresses (rather than offsets) are available.
6031 * The /i format now outputs any trailing branch delay slot instructions
6032 immediately following the last instruction within the count specified.
6034 * The GDB remote protocol "T" stop reply packet now supports a
6035 "library" response. Combined with the new "qXfer:libraries:read"
6036 packet, this response allows GDB to debug shared libraries on targets
6037 where the operating system manages the list of loaded libraries (e.g.
6038 Windows and SymbianOS).
6040 * The GDB remote stub, gdbserver, now supports dynamic link libraries
6041 (DLLs) on Windows and Windows CE targets.
6043 * GDB now supports a faster verification that a .debug file matches its binary
6044 according to its build-id signature, if the signature is present.
6050 Enable or disable hardware flow control (RTS/CTS) on the serial port
6051 when debugging using remote targets.
6053 set mem inaccessible-by-default
6054 show mem inaccessible-by-default
6055 If the target supplies a memory map, for instance via the remote
6056 protocol's "qXfer:memory-map:read" packet, setting this variable
6057 prevents GDB from accessing memory outside the memory map. This
6058 is useful for targets with memory mapped registers or which react
6059 badly to accesses of unmapped address space.
6061 set breakpoint auto-hw
6062 show breakpoint auto-hw
6063 If the target supplies a memory map, for instance via the remote
6064 protocol's "qXfer:memory-map:read" packet, setting this variable
6065 lets GDB use hardware breakpoints automatically for memory regions
6066 where it can not use software breakpoints. This covers both the
6067 "break" command and internal breakpoints used for other commands
6068 including "next" and "finish".
6071 catch exception unhandled
6072 Stop the program execution when Ada exceptions are raised.
6075 Stop the program execution when an Ada assertion failed.
6079 Set an alternate system root for target files. This is a more
6080 general version of "set solib-absolute-prefix", which is now
6081 an alias to "set sysroot".
6084 Provide extended SPU facility status information. This set of
6085 commands is available only when debugging the Cell/B.E. SPU
6088 * New native configurations
6090 OpenBSD/sh sh*-*openbsd*
6093 unset tdesc filename
6095 Use the specified local file as an XML target description, and do
6096 not query the target for its built-in description.
6100 OpenBSD/sh sh*-*-openbsd*
6101 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
6102 Toshiba Media Processor mep-elf
6104 * New remote packets
6107 Ignore the specified signals; pass them directly to the debugged program
6108 without stopping other threads or reporting them to GDB.
6110 qXfer:features:read:
6111 Read an XML target description from the target, which describes its
6116 Read or write contents of an spufs file on the target system. These
6117 packets are available only on the Cell/B.E. SPU architecture.
6119 qXfer:libraries:read:
6120 Report the loaded shared libraries. Combined with new "T" packet
6121 response, this packet allows GDB to debug shared libraries on
6122 targets where the operating system manages the list of loaded
6123 libraries (e.g. Windows and SymbianOS).
6127 Support for these obsolete configurations has been removed.
6135 i[34567]86-*-lynxos*
6136 i[34567]86-*-netware*
6137 i[34567]86-*-sco3.2v5*
6138 i[34567]86-*-sco3.2v4*
6140 i[34567]86-*-sysv4.2*
6143 i[34567]86-*-unixware2*
6144 i[34567]86-*-unixware*
6153 * Other removed features
6160 Various m68k-only ROM monitors.
6167 Various Renesas ROM monitors and debugging interfaces for SH and
6172 Support for a Macraigor serial interface to on-chip debugging.
6173 GDB does not directly support the newer parallel or USB
6178 A debug information format. The predecessor to DWARF 2 and
6179 DWARF 3, which are still supported.
6181 Support for the HP aCC compiler on HP-UX/PA-RISC
6183 SOM-encapsulated symbolic debugging information, automatic
6184 invocation of pxdb, and the aCC custom C++ ABI. This does not
6185 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
6186 with aCC can still be debugged on an assembly level.
6188 MIPS ".pdr" sections
6190 A MIPS-specific format used to describe stack frame layout
6191 in debugging information.
6195 GDB could work with an older version of Guile to debug
6196 the interpreter and Scheme programs running in it.
6198 set mips stack-arg-size
6199 set mips saved-gpreg-size
6201 Use "set mips abi" to control parameter passing for MIPS.
6203 *** Changes in GDB 6.6
6208 Cell Broadband Engine SPU spu-elf
6210 * GDB can now be configured as a cross-debugger targeting native Windows
6211 (mingw32) or Cygwin. It can communicate with a remote debugging stub
6212 running on a Windows system over TCP/IP to debug Windows programs.
6214 * The GDB remote stub, gdbserver, has been updated to support Windows and
6215 Cygwin debugging. Both single-threaded and multi-threaded programs are
6218 * The "set trust-readonly-sections" command works again. This command was
6219 broken in GDB 6.3, 6.4, and 6.5.
6221 * The "load" command now supports writing to flash memory, if the remote
6222 stub provides the required support.
6224 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
6225 longer requires symbolic debug information (e.g. DWARF-2).
6230 unset substitute-path
6231 show substitute-path
6232 Manage a list of substitution rules that GDB uses to rewrite the name
6233 of the directories where the sources are located. This can be useful
6234 for instance when the sources were moved to a different location
6235 between compilation and debugging.
6239 Print each CLI command as it is executed. Each command is prefixed with
6240 a number of `+' symbols representing the nesting depth.
6241 The source command now has a `-v' option to enable the same feature.
6245 The ARM Demon monitor support (RDP protocol, "target rdp").
6247 Kernel Object Display, an embedded debugging feature which only worked with
6248 an obsolete version of Cisco IOS.
6250 The 'set download-write-size' and 'show download-write-size' commands.
6252 * New remote packets
6255 Tell a stub about GDB client features, and request remote target features.
6256 The first feature implemented is PacketSize, which allows the target to
6257 specify the size of packets it can handle - to minimize the number of
6258 packets required and improve performance when connected to a remote
6262 Fetch an OS auxilliary vector from the remote stub. This packet is a
6263 more efficient replacement for qPart:auxv:read.
6265 qXfer:memory-map:read:
6266 Fetch a memory map from the remote stub, including information about
6267 RAM, ROM, and flash memory devices.
6272 Erase and program a flash memory device.
6274 * Removed remote packets
6277 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
6278 used it, and only gdbserver implemented it.
6280 *** Changes in GDB 6.5
6284 Renesas M32C/M16C m32c-elf
6286 Morpho Technologies ms1 ms1-elf
6290 init-if-undefined Initialize a convenience variable, but
6291 only if it doesn't already have a value.
6293 The following commands are presently only implemented for native GNU/Linux:
6295 checkpoint Save a snapshot of the program state.
6297 restart <n> Return the program state to a
6298 previously saved state.
6300 info checkpoints List currently saved checkpoints.
6302 delete-checkpoint <n> Delete a previously saved checkpoint.
6304 set|show detach-on-fork Tell gdb whether to detach from a newly
6305 forked process, or to keep debugging it.
6307 info forks List forks of the user program that
6308 are available to be debugged.
6310 fork <n> Switch to debugging one of several
6311 forks of the user program that are
6312 available to be debugged.
6314 delete-fork <n> Delete a fork from the list of forks
6315 that are available to be debugged (and
6316 kill the forked process).
6318 detach-fork <n> Delete a fork from the list of forks
6319 that are available to be debugged (and
6320 allow the process to continue).
6324 Morpho Technologies ms2 ms1-elf
6326 * Improved Windows host support
6328 GDB now builds as a cross debugger hosted on i686-mingw32, including
6329 native console support, and remote communications using either
6330 network sockets or serial ports.
6332 * Improved Modula-2 language support
6334 GDB can now print most types in the Modula-2 syntax. This includes:
6335 basic types, set types, record types, enumerated types, range types,
6336 pointer types and ARRAY types. Procedure var parameters are correctly
6337 printed and hexadecimal addresses and character constants are also
6338 written in the Modula-2 syntax. Best results can be obtained by using
6339 GNU Modula-2 together with the -gdwarf-2 command line option.
6343 The ARM rdi-share module.
6345 The Netware NLM debug server.
6347 *** Changes in GDB 6.4
6349 * New native configurations
6351 OpenBSD/arm arm*-*-openbsd*
6352 OpenBSD/mips64 mips64-*-openbsd*
6356 Morpho Technologies ms1 ms1-elf
6358 * New command line options
6360 --batch-silent As for --batch, but totally silent.
6361 --return-child-result The debugger will exist with the same value
6362 the child (debugged) program exited with.
6363 --eval-command COMMAND, -ex COMMAND
6364 Execute a single GDB CLI command. This may be
6365 specified multiple times and in conjunction
6366 with the --command (-x) option.
6368 * Deprecated commands removed
6370 The following commands, that were deprecated in 2000, have been
6374 set|show arm disassembly-flavor set|show arm disassembler
6375 othernames set arm disassembler
6376 set|show remotedebug set|show debug remote
6377 set|show archdebug set|show debug arch
6378 set|show eventdebug set|show debug event
6381 * New BSD user-level threads support
6383 It is now possible to debug programs using the user-level threads
6384 library on OpenBSD and FreeBSD. Currently supported (target)
6387 FreeBSD/amd64 x86_64-*-freebsd*
6388 FreeBSD/i386 i386-*-freebsd*
6389 OpenBSD/i386 i386-*-openbsd*
6391 Note that the new kernel threads libraries introduced in FreeBSD 5.x
6392 are not yet supported.
6394 * New support for Matsushita MN10300 w/sim added
6395 (Work in progress). mn10300-elf.
6397 * REMOVED configurations and files
6399 VxWorks and the XDR protocol *-*-vxworks
6400 Motorola MCORE mcore-*-*
6401 National Semiconductor NS32000 ns32k-*-*
6403 * New "set print array-indexes" command
6405 After turning this setting "on", GDB prints the index of each element
6406 when displaying arrays. The default is "off" to preserve the previous
6409 * VAX floating point support
6411 GDB now supports the not-quite-ieee VAX F and D floating point formats.
6413 * User-defined command support
6415 In addition to using $arg0..$arg9 for argument passing, it is now possible
6416 to use $argc to determine now many arguments have been passed. See the
6417 section on user-defined commands in the user manual for more information.
6419 *** Changes in GDB 6.3:
6421 * New command line option
6423 GDB now accepts -l followed by a number to set the timeout for remote
6426 * GDB works with GCC -feliminate-dwarf2-dups
6428 GDB now supports a more compact representation of DWARF-2 debug
6429 information using DW_FORM_ref_addr references. These are produced
6430 by GCC with the option -feliminate-dwarf2-dups and also by some
6431 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
6432 to use -feliminate-dwarf2-dups.
6434 * Internationalization
6436 When supported by the host system, GDB will be built with
6437 internationalization (libintl). The task of marking up the sources is
6438 continued, we're looking forward to our first translation.
6442 Initial support for debugging programs compiled with the GNAT
6443 implementation of the Ada programming language has been integrated
6444 into GDB. In this release, support is limited to expression evaluation.
6446 * New native configurations
6448 GNU/Linux/m32r m32r-*-linux-gnu
6452 GDB's remote protocol now includes support for the 'p' packet. This
6453 packet is used to fetch individual registers from a remote inferior.
6455 * END-OF-LIFE registers[] compatibility module
6457 GDB's internal register infrastructure has been completely rewritten.
6458 The new infrastructure making possible the implementation of key new
6459 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
6462 GDB 6.3 will be the last release to include the registers[]
6463 compatibility module that allowed out-of-date configurations to
6464 continue to work. This change directly impacts the following
6474 powerpc bdm protocol
6476 Unless there is activity to revive these configurations, they will be
6477 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
6479 * OBSOLETE configurations and files
6481 Configurations that have been declared obsolete in this release have
6482 been commented out. Unless there is activity to revive these
6483 configurations, the next release of GDB will have their sources
6484 permanently REMOVED.
6493 *** Changes in GDB 6.2.1:
6495 * MIPS `break main; run' gave an heuristic-fence-post warning
6497 When attempting to run even a simple program, a warning about
6498 heuristic-fence-post being hit would be reported. This problem has
6501 * MIPS IRIX 'long double' crashed GDB
6503 When examining a long double variable, GDB would get a segmentation
6504 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
6505 IRIX long double values).
6509 A bug in the VAX stack code was causing problems with the "next"
6510 command. This problem has been fixed.
6512 *** Changes in GDB 6.2:
6514 * Fix for ``many threads''
6516 On GNU/Linux systems that use the NPTL threads library, a program
6517 rapidly creating and deleting threads would confuse GDB leading to the
6520 ptrace: No such process.
6521 thread_db_get_info: cannot get thread info: generic error
6523 This problem has been fixed.
6525 * "-async" and "-noasync" options removed.
6527 Support for the broken "-noasync" option has been removed (it caused
6530 * New ``start'' command.
6532 This command runs the program until the beginning of the main procedure.
6534 * New BSD Kernel Data Access Library (libkvm) interface
6536 Using ``target kvm'' it is now possible to debug kernel core dumps and
6537 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
6538 platforms. Currently supported (native-only) configurations are:
6540 FreeBSD/amd64 x86_64-*-freebsd*
6541 FreeBSD/i386 i?86-*-freebsd*
6542 NetBSD/i386 i?86-*-netbsd*
6543 NetBSD/m68k m68*-*-netbsd*
6544 NetBSD/sparc sparc-*-netbsd*
6545 OpenBSD/amd64 x86_64-*-openbsd*
6546 OpenBSD/i386 i?86-*-openbsd*
6547 OpenBSD/m68k m68*-openbsd*
6548 OpenBSD/sparc sparc-*-openbsd*
6550 * Signal trampoline code overhauled
6552 Many generic problems with GDB's signal handling code have been fixed.
6553 These include: backtraces through non-contiguous stacks; recognition
6554 of sa_sigaction signal trampolines; backtrace from a NULL pointer
6555 call; backtrace through a signal trampoline; step into and out of
6556 signal handlers; and single-stepping in the signal trampoline.
6558 Please note that kernel bugs are a limiting factor here. These
6559 features have been shown to work on an s390 GNU/Linux system that
6560 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
6562 * Cygwin support for DWARF 2 added.
6564 * New native configurations
6566 GNU/Linux/hppa hppa*-*-linux*
6567 OpenBSD/hppa hppa*-*-openbsd*
6568 OpenBSD/m68k m68*-*-openbsd*
6569 OpenBSD/m88k m88*-*-openbsd*
6570 OpenBSD/powerpc powerpc-*-openbsd*
6571 NetBSD/vax vax-*-netbsd*
6572 OpenBSD/vax vax-*-openbsd*
6574 * END-OF-LIFE frame compatibility module
6576 GDB's internal frame infrastructure has been completely rewritten.
6577 The new infrastructure making it possible to support key new features
6578 including DWARF 2 Call Frame Information. To aid in the task of
6579 migrating old configurations to this new infrastructure, a
6580 compatibility module, that allowed old configurations to continue to
6581 work, was also included.
6583 GDB 6.2 will be the last release to include this frame compatibility
6584 module. This change directly impacts the following configurations:
6594 Unless there is activity to revive these configurations, they will be
6595 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
6597 * REMOVED configurations and files
6599 Sun 3, running SunOS 3 m68*-*-sunos3*
6600 Sun 3, running SunOS 4 m68*-*-sunos4*
6601 Sun 2, running SunOS 3 m68000-*-sunos3*
6602 Sun 2, running SunOS 4 m68000-*-sunos4*
6603 Motorola 680x0 running LynxOS m68*-*-lynxos*
6604 AT&T 3b1/Unix pc m68*-att-*
6605 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6606 decstation mips-dec-* mips-little-*
6607 riscos mips-*-riscos* mips-*-sysv*
6608 sonymips mips-sony-*
6609 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6611 *** Changes in GDB 6.1.1:
6613 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
6615 The TUI (Text-mode User Interface) is now built as part of a default
6616 GDB configuration. It is enabled by either selecting the TUI with the
6617 command line option "-i=tui" or by running the separate "gdbtui"
6618 program. For more information on the TUI, see the manual "Debugging
6621 * Pending breakpoint support (also included in GDB 6.1)
6623 Support has been added to allow you to specify breakpoints in shared
6624 libraries that have not yet been loaded. If a breakpoint location
6625 cannot be found, and the "breakpoint pending" option is set to auto,
6626 GDB queries you if you wish to make the breakpoint pending on a future
6627 shared-library load. If and when GDB resolves the breakpoint symbol,
6628 the pending breakpoint is removed as one or more regular breakpoints
6631 Pending breakpoints are very useful for GCJ Java debugging.
6633 * Fixed ISO-C build problems
6635 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
6636 non ISO-C code that stopped them being built using a more strict ISO-C
6637 compiler (e.g., IBM's C compiler).
6639 * Fixed build problem on IRIX 5
6641 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
6642 wasn't able to compile compile on an IRIX 5 system.
6644 * Added execute permission to gdb/gdbserver/configure
6646 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
6647 permission. This bug would cause configure to fail on a number of
6648 systems (Solaris, IRIX). Ref: server/519.
6650 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
6652 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
6653 has been updated to use constant array sizes.
6655 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
6657 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
6658 its generated DWARF Call Frame Info. This encoding was causing GDB to
6659 panic, that panic has been fixed. Ref: gdb/1628.
6661 * Fixed a problem when examining parameters in shared library code.
6663 When examining parameters in optimized shared library code generated
6664 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
6665 not available''. GDB now correctly displays the variable's value.
6667 *** Changes in GDB 6.1:
6669 * Removed --with-mmalloc
6671 Support for the mmalloc memory manager has been removed, as it
6672 conflicted with the internal gdb byte cache.
6674 * Changes in AMD64 configurations
6676 The AMD64 target now includes the %cs and %ss registers. As a result
6677 the AMD64 remote protocol has changed; this affects the floating-point
6678 and SSE registers. If you rely on those registers for your debugging,
6679 you should upgrade gdbserver on the remote side.
6681 * Revised SPARC target
6683 The SPARC target has been completely revised, incorporating the
6684 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
6685 support for LynxOS and SunOS 4 has been dropped. Calling functions
6686 from within GDB on operating systems with a non-executable stack
6687 (Solaris, OpenBSD) now works.
6691 GDB has a new C++ demangler which does a better job on the mangled
6692 names generated by current versions of g++. It also runs faster, so
6693 with this and other changes gdb should now start faster on large C++
6696 * DWARF 2 Location Expressions
6698 GDB support for location expressions has been extended to support function
6699 arguments and frame bases. Older versions of GDB could crash when they
6702 * C++ nested types and namespaces
6704 GDB's support for nested types and namespaces in C++ has been
6705 improved, especially if you use the DWARF 2 debugging format. (This
6706 is the default for recent versions of GCC on most platforms.)
6707 Specifically, if you have a class "Inner" defined within a class or
6708 namespace "Outer", then GDB realizes that the class's name is
6709 "Outer::Inner", not simply "Inner". This should greatly reduce the
6710 frequency of complaints about not finding RTTI symbols. In addition,
6711 if you are stopped at inside of a function defined within a namespace,
6712 GDB modifies its name lookup accordingly.
6714 * New native configurations
6716 NetBSD/amd64 x86_64-*-netbsd*
6717 OpenBSD/amd64 x86_64-*-openbsd*
6718 OpenBSD/alpha alpha*-*-openbsd*
6719 OpenBSD/sparc sparc-*-openbsd*
6720 OpenBSD/sparc64 sparc64-*-openbsd*
6722 * New debugging protocols
6724 M32R with SDI protocol m32r-*-elf*
6726 * "set prompt-escape-char" command deleted.
6728 The command "set prompt-escape-char" has been deleted. This command,
6729 and its very obscure effect on GDB's prompt, was never documented,
6730 tested, nor mentioned in the NEWS file.
6732 * OBSOLETE configurations and files
6734 Configurations that have been declared obsolete in this release have
6735 been commented out. Unless there is activity to revive these
6736 configurations, the next release of GDB will have their sources
6737 permanently REMOVED.
6739 Sun 3, running SunOS 3 m68*-*-sunos3*
6740 Sun 3, running SunOS 4 m68*-*-sunos4*
6741 Sun 2, running SunOS 3 m68000-*-sunos3*
6742 Sun 2, running SunOS 4 m68000-*-sunos4*
6743 Motorola 680x0 running LynxOS m68*-*-lynxos*
6744 AT&T 3b1/Unix pc m68*-att-*
6745 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
6746 decstation mips-dec-* mips-little-*
6747 riscos mips-*-riscos* mips-*-sysv*
6748 sonymips mips-sony-*
6749 sysv mips*-*-sysv4* (IRIX 5/6 not included)
6751 * REMOVED configurations and files
6753 SGI Irix-4.x mips-sgi-irix4 or iris4
6754 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6755 Z8000 simulator z8k-zilog-none or z8ksim
6756 Matsushita MN10200 w/simulator mn10200-*-*
6757 H8/500 simulator h8500-hitachi-hms or h8500hms
6758 HP/PA running BSD hppa*-*-bsd*
6759 HP/PA running OSF/1 hppa*-*-osf*
6760 HP/PA Pro target hppa*-*-pro*
6761 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6762 386BSD i[3456]86-*-bsd*
6763 Sequent family i[3456]86-sequent-sysv4*
6764 i[3456]86-sequent-sysv*
6765 i[3456]86-sequent-bsd*
6766 SPARC running LynxOS sparc-*-lynxos*
6767 SPARC running SunOS 4 sparc-*-sunos4*
6768 Tsqware Sparclet sparclet-*-*
6769 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6771 *** Changes in GDB 6.0:
6775 Support for debugging the Objective-C programming language has been
6776 integrated into GDB.
6778 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
6780 DWARF 2's Call Frame Information makes available compiler generated
6781 information that more exactly describes the program's run-time stack.
6782 By using this information, GDB is able to provide more robust stack
6785 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
6786 have been updated to use a new backtrace mechanism which includes
6787 DWARF 2 CFI support.
6791 GDB's remote protocol has been extended to include support for hosted
6792 file I/O (where the remote target uses GDB's file system). See GDB's
6793 remote protocol documentation for details.
6795 * All targets using the new architecture framework.
6797 All of GDB's targets have been updated to use the new internal
6798 architecture framework. The way is now open for future GDB releases
6799 to include cross-architecture native debugging support (i386 on amd64,
6802 * GNU/Linux's Thread Local Storage (TLS)
6804 GDB now includes support for for the GNU/Linux implementation of
6805 per-thread variables.
6807 * GNU/Linux's Native POSIX Thread Library (NPTL)
6809 GDB's thread code has been updated to work with either the new
6810 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
6812 * Separate debug info.
6814 GDB, in conjunction with BINUTILS, now supports a mechanism for
6815 automatically loading debug information from a separate file. Instead
6816 of shipping full debug and non-debug versions of system libraries,
6817 system integrators can now instead ship just the stripped libraries
6818 and optional debug files.
6820 * DWARF 2 Location Expressions
6822 DWARF 2 Location Expressions allow the compiler to more completely
6823 describe the location of variables (even in optimized code) to the
6826 GDB now includes preliminary support for location expressions (support
6827 for DW_OP_piece is still missing).
6831 A number of long standing bugs that caused GDB to die while starting a
6832 Java application have been fixed. GDB's Java support is now
6833 considered "useable".
6835 * GNU/Linux support for fork, vfork, and exec.
6837 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
6838 commands are now implemented for GNU/Linux. They require a 2.5.x or later
6841 * GDB supports logging output to a file
6843 There are two new commands, "set logging" and "show logging", which can be
6844 used to capture GDB's output to a file.
6846 * The meaning of "detach" has changed for gdbserver
6848 The "detach" command will now resume the application, as documented. To
6849 disconnect from gdbserver and leave it stopped, use the new "disconnect"
6852 * d10v, m68hc11 `regs' command deprecated
6854 The `info registers' command has been updated so that it displays the
6855 registers using a format identical to the old `regs' command.
6859 A new command, "maint set profile on/off", has been added. This command can
6860 be used to enable or disable profiling while running GDB, to profile a
6861 session or a set of commands. In addition there is a new configure switch,
6862 "--enable-profiling", which will cause GDB to be compiled with profiling
6863 data, for more informative profiling results.
6865 * Default MI syntax changed to "mi2".
6867 The default MI (machine interface) syntax, enabled by the command line
6868 option "-i=mi", has been changed to "mi2". The previous MI syntax,
6869 "mi1", can be enabled by specifying the option "-i=mi1".
6871 Support for the original "mi0" syntax (included in GDB 5.0) has been
6874 Fix for gdb/192: removed extraneous space when displaying frame level.
6875 Fix for gdb/672: update changelist is now output in mi list format.
6876 Fix for gdb/702: a -var-assign that updates the value now shows up
6877 in a subsequent -var-update.
6879 * New native configurations.
6881 FreeBSD/amd64 x86_64-*-freebsd*
6883 * Multi-arched targets.
6885 HP/PA HPUX11 hppa*-*-hpux*
6886 Renesas M32R/D w/simulator m32r-*-elf*
6888 * OBSOLETE configurations and files
6890 Configurations that have been declared obsolete in this release have
6891 been commented out. Unless there is activity to revive these
6892 configurations, the next release of GDB will have their sources
6893 permanently REMOVED.
6895 Z8000 simulator z8k-zilog-none or z8ksim
6896 Matsushita MN10200 w/simulator mn10200-*-*
6897 H8/500 simulator h8500-hitachi-hms or h8500hms
6898 HP/PA running BSD hppa*-*-bsd*
6899 HP/PA running OSF/1 hppa*-*-osf*
6900 HP/PA Pro target hppa*-*-pro*
6901 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
6902 Sequent family i[3456]86-sequent-sysv4*
6903 i[3456]86-sequent-sysv*
6904 i[3456]86-sequent-bsd*
6905 Tsqware Sparclet sparclet-*-*
6906 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6908 * REMOVED configurations and files
6911 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6912 IBM AIX PS/2 i[3456]86-*-aix
6913 i386 running Mach 3.0 i[3456]86-*-mach3*
6914 i386 running Mach i[3456]86-*-mach*
6915 i386 running OSF/1 i[3456]86-*osf1mk*
6916 HP/Apollo 68k Family m68*-apollo*-sysv*,
6918 m68*-hp-bsd*, m68*-hp-hpux*
6919 Argonaut Risc Chip (ARC) arc-*-*
6920 Mitsubishi D30V d30v-*-*
6921 Fujitsu FR30 fr30-*-elf*
6922 OS/9000 i[34]86-*-os9k
6923 I960 with MON960 i960-*-coff
6925 * MIPS $fp behavior changed
6927 The convenience variable $fp, for the MIPS, now consistently returns
6928 the address of the current frame's base. Previously, depending on the
6929 context, $fp could refer to either $sp or the current frame's base
6930 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
6931 The GNU Source-Level Debugger''.
6933 *** Changes in GDB 5.3:
6935 * GNU/Linux shared library multi-threaded performance improved.
6937 When debugging a multi-threaded application on GNU/Linux, GDB now uses
6938 `/proc', in preference to `ptrace' for memory reads. This may result
6939 in an improvement in the start-up time of multi-threaded, shared
6940 library applications when run under GDB. One GDB user writes: ``loads
6941 shared libs like mad''.
6943 * ``gdbserver'' now supports multi-threaded applications on some targets
6945 Support for debugging multi-threaded applications which use
6946 the GNU/Linux LinuxThreads package has been added for
6947 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
6948 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
6950 * GDB now supports C/C++ preprocessor macros.
6952 GDB now expands preprocessor macro invocations in C/C++ expressions,
6953 and provides various commands for showing macro definitions and how
6956 The new command `macro expand EXPRESSION' expands any macro
6957 invocations in expression, and shows the result.
6959 The new command `show macro MACRO-NAME' shows the definition of the
6960 macro named MACRO-NAME, and where it was defined.
6962 Most compilers don't include information about macros in the debugging
6963 information by default. In GCC 3.1, for example, you need to compile
6964 your program with the options `-gdwarf-2 -g3'. If the macro
6965 information is present in the executable, GDB will read it.
6967 * Multi-arched targets.
6969 DEC Alpha (partial) alpha*-*-*
6970 DEC VAX (partial) vax-*-*
6972 National Semiconductor NS32000 (partial) ns32k-*-*
6973 Motorola 68000 (partial) m68k-*-*
6974 Motorola MCORE mcore-*-*
6978 Fujitsu FRV architecture added by Red Hat frv*-*-*
6981 * New native configurations
6983 Alpha NetBSD alpha*-*-netbsd*
6984 SH NetBSD sh*-*-netbsdelf*
6985 MIPS NetBSD mips*-*-netbsd*
6986 UltraSPARC NetBSD sparc64-*-netbsd*
6988 * OBSOLETE configurations and files
6990 Configurations that have been declared obsolete in this release have
6991 been commented out. Unless there is activity to revive these
6992 configurations, the next release of GDB will have their sources
6993 permanently REMOVED.
6995 Mitsubishi D30V d30v-*-*
6996 OS/9000 i[34]86-*-os9k
6997 IBM AIX PS/2 i[3456]86-*-aix
6998 Fujitsu FR30 fr30-*-elf*
6999 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
7000 Argonaut Risc Chip (ARC) arc-*-*
7001 i386 running Mach 3.0 i[3456]86-*-mach3*
7002 i386 running Mach i[3456]86-*-mach*
7003 i386 running OSF/1 i[3456]86-*osf1mk*
7004 HP/Apollo 68k Family m68*-apollo*-sysv*,
7006 m68*-hp-bsd*, m68*-hp-hpux*
7007 I960 with MON960 i960-*-coff
7009 * OBSOLETE languages
7011 CHILL, a Pascal like language used by telecommunications companies.
7013 * REMOVED configurations and files
7015 AMD 29k family via UDI a29k-amd-udi, udi29k
7016 A29K VxWorks a29k-*-vxworks
7017 AMD 29000 embedded, using EBMON a29k-none-none
7018 AMD 29000 embedded with COFF a29k-none-coff
7019 AMD 29000 embedded with a.out a29k-none-aout
7021 testsuite/gdb.hp/gdb.threads-hp/ directory
7023 * New command "set max-user-call-depth <nnn>"
7025 This command allows the user to limit the call depth of user-defined
7026 commands. The default is 1024.
7028 * Changes in FreeBSD/i386 native debugging.
7030 Support for the "generate-core-file" has been added.
7032 * New commands "dump", "append", and "restore".
7034 These commands allow data to be copied from target memory
7035 to a bfd-format or binary file (dump and append), and back
7036 from a file into memory (restore).
7038 * Improved "next/step" support on multi-processor Alpha Tru64.
7040 The previous single-step mechanism could cause unpredictable problems,
7041 including the random appearance of SIGSEGV or SIGTRAP signals. The use
7042 of a software single-step mechanism prevents this.
7044 *** Changes in GDB 5.2.1:
7052 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
7053 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
7054 Fix, by Joel Brobecker imported from mainline.
7056 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
7057 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
7058 Fix, by Fred Fish, imported from mainline.
7060 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
7061 Surprisingly enough, it works now.
7062 By Michal Ludvig, imported from mainline.
7064 i386 hardware watchpoint support:
7065 avoid misses on second run for some targets.
7066 By Pierre Muller, imported from mainline.
7068 *** Changes in GDB 5.2:
7070 * New command "set trust-readonly-sections on[off]".
7072 This command is a hint that tells gdb that read-only sections
7073 really are read-only (ie. that their contents will not change).
7074 In this mode, gdb will go to the object file rather than the
7075 target to read memory from read-only sections (such as ".text").
7076 This can be a significant performance improvement on some
7077 (notably embedded) targets.
7079 * New command "generate-core-file" (or "gcore").
7081 This new gdb command allows the user to drop a core file of the child
7082 process state at any time. So far it's been implemented only for
7083 GNU/Linux and Solaris, but should be relatively easily ported to other
7084 hosts. Argument is core file name (defaults to core.<pid>).
7086 * New command line option
7088 GDB now accepts --pid or -p followed by a process id.
7090 * Change in command line behavior -- corefiles vs. process ids.
7092 There is a subtle behavior in the way in which GDB handles
7093 command line arguments. The first non-flag argument is always
7094 a program to debug, but the second non-flag argument may either
7095 be a corefile or a process id. Previously, GDB would attempt to
7096 open the second argument as a corefile, and if that failed, would
7097 issue a superfluous error message and then attempt to attach it as
7098 a process. Now, if the second argument begins with a non-digit,
7099 it will be treated as a corefile. If it begins with a digit,
7100 GDB will attempt to attach it as a process, and if no such process
7101 is found, will then attempt to open it as a corefile.
7103 * Changes in ARM configurations.
7105 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
7106 configuration is fully multi-arch.
7108 * New native configurations
7110 ARM NetBSD arm*-*-netbsd*
7111 x86 OpenBSD i[3456]86-*-openbsd*
7112 AMD x86-64 running GNU/Linux x86_64-*-linux-*
7113 Sparc64 running FreeBSD sparc64-*-freebsd*
7117 Sanyo XStormy16 xstormy16-elf
7119 * OBSOLETE configurations and files
7121 Configurations that have been declared obsolete in this release have
7122 been commented out. Unless there is activity to revive these
7123 configurations, the next release of GDB will have their sources
7124 permanently REMOVED.
7126 AMD 29k family via UDI a29k-amd-udi, udi29k
7127 A29K VxWorks a29k-*-vxworks
7128 AMD 29000 embedded, using EBMON a29k-none-none
7129 AMD 29000 embedded with COFF a29k-none-coff
7130 AMD 29000 embedded with a.out a29k-none-aout
7132 testsuite/gdb.hp/gdb.threads-hp/ directory
7134 * REMOVED configurations and files
7136 TI TMS320C80 tic80-*-*
7138 PowerPC Solaris powerpcle-*-solaris*
7139 PowerPC Windows NT powerpcle-*-cygwin32
7140 PowerPC Netware powerpc-*-netware*
7141 Harris/CXUX m88k m88*-harris-cxux*
7142 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7143 ns32k-utek-sysv* ns32k-utek-*
7144 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7145 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7146 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7147 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7148 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
7150 * Changes to command line processing
7152 The new `--args' feature can be used to specify command-line arguments
7153 for the inferior from gdb's command line.
7155 * Changes to key bindings
7157 There is a new `operate-and-get-next' function bound to `C-o'.
7159 *** Changes in GDB 5.1.1
7161 Fix compile problem on DJGPP.
7163 Fix a problem with floating-point registers on the i386 being
7166 Fix to stop GDB crashing on .debug_str debug info.
7168 Numerous documentation fixes.
7170 Numerous testsuite fixes.
7172 *** Changes in GDB 5.1:
7174 * New native configurations
7176 Alpha FreeBSD alpha*-*-freebsd*
7177 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
7178 MIPS GNU/Linux mips*-*-linux*
7179 MIPS SGI Irix 6.x mips*-sgi-irix6*
7180 ia64 AIX ia64-*-aix*
7181 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
7185 Motorola 68HC11 and 68HC12 m68hc11-elf
7187 UltraSparc running GNU/Linux sparc64-*-linux*
7189 * OBSOLETE configurations and files
7191 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
7192 Harris/CXUX m88k m88*-harris-cxux*
7193 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
7194 ns32k-utek-sysv* ns32k-utek-*
7195 TI TMS320C80 tic80-*-*
7197 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
7198 PowerPC Solaris powerpcle-*-solaris*
7199 PowerPC Windows NT powerpcle-*-cygwin32
7200 PowerPC Netware powerpc-*-netware*
7201 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
7202 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
7203 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
7204 Apple Macintosh (MPW) host N/A
7206 stuff.c (Program to stuff files into a specially prepared space in kdb)
7207 kdb-start.c (Main loop for the standalone kernel debugger)
7209 Configurations that have been declared obsolete in this release have
7210 been commented out. Unless there is activity to revive these
7211 configurations, the next release of GDB will have their sources
7212 permanently REMOVED.
7214 * REMOVED configurations and files
7216 Altos 3068 m68*-altos-*
7217 Convex c1-*-*, c2-*-*
7219 ARM RISCix arm-*-* (as host)
7223 * GDB has been converted to ISO C.
7225 GDB's source code has been converted to ISO C. In particular, the
7226 sources are fully protoized, and rely on standard headers being
7231 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
7233 * The MI enabled by default.
7235 The new machine oriented interface (MI) introduced in GDB 5.0 has been
7236 revised and enabled by default. Packages which use GDB as a debugging
7237 engine behind a UI or another front end are encouraged to switch to
7238 using the GDB/MI interface, instead of the old annotations interface
7239 which is now deprecated.
7241 * Support for debugging Pascal programs.
7243 GDB now includes support for debugging Pascal programs. The following
7244 main features are supported:
7246 - Pascal-specific data types such as sets;
7248 - automatic recognition of Pascal sources based on file-name
7251 - Pascal-style display of data types, variables, and functions;
7253 - a Pascal expression parser.
7255 However, some important features are not yet supported.
7257 - Pascal string operations are not supported at all;
7259 - there are some problems with boolean types;
7261 - Pascal type hexadecimal constants are not supported
7262 because they conflict with the internal variables format;
7264 - support for Pascal objects and classes is not full yet;
7266 - unlike Pascal, GDB is case-sensitive for symbol names.
7268 * Changes in completion.
7270 Commands such as `shell', `run' and `set args', which pass arguments
7271 to inferior programs, now complete on file names, similar to what
7272 users expect at the shell prompt.
7274 Commands which accept locations, such as `disassemble', `print',
7275 `breakpoint', `until', etc. now complete on filenames as well as
7276 program symbols. Thus, if you type "break foob TAB", and the source
7277 files linked into the programs include `foobar.c', that file name will
7278 be one of the candidates for completion. However, file names are not
7279 considered for completion after you typed a colon that delimits a file
7280 name from a name of a function in that file, as in "break foo.c:bar".
7282 `set demangle-style' completes on available demangling styles.
7284 * New platform-independent commands:
7286 It is now possible to define a post-hook for a command as well as a
7287 hook that runs before the command. For more details, see the
7288 documentation of `hookpost' in the GDB manual.
7290 * Changes in GNU/Linux native debugging.
7292 Support for debugging multi-threaded programs has been completely
7293 revised for all platforms except m68k and sparc. You can now debug as
7294 many threads as your system allows you to have.
7296 Attach/detach is supported for multi-threaded programs.
7298 Support for SSE registers was added for x86. This doesn't work for
7299 multi-threaded programs though.
7301 * Changes in MIPS configurations.
7303 Multi-arch support is enabled for all MIPS configurations.
7305 GDB can now be built as native debugger on SGI Irix 6.x systems for
7306 debugging n32 executables. (Debugging 64-bit executables is not yet
7309 * Unified support for hardware watchpoints in all x86 configurations.
7311 Most (if not all) native x86 configurations support hardware-assisted
7312 breakpoints and watchpoints in a unified manner. This support
7313 implements debug register sharing between watchpoints, which allows to
7314 put a virtually infinite number of watchpoints on the same address,
7315 and also supports watching regions up to 16 bytes with several debug
7318 The new maintenance command `maintenance show-debug-regs' toggles
7319 debugging print-outs in functions that insert, remove, and test
7320 watchpoints and hardware breakpoints.
7322 * Changes in the DJGPP native configuration.
7324 New command ``info dos sysinfo'' displays assorted information about
7325 the CPU, OS, memory, and DPMI server.
7327 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
7328 display information about segment descriptors stored in GDT, LDT, and
7331 New commands ``info dos pde'' and ``info dos pte'' display entries
7332 from Page Directory and Page Tables (for now works with CWSDPMI only).
7333 New command ``info dos address-pte'' displays the Page Table entry for
7334 a given linear address.
7336 GDB can now pass command lines longer than 126 characters to the
7337 program being debugged (requires an update to the libdbg.a library
7338 which is part of the DJGPP development kit).
7340 DWARF2 debug info is now supported.
7342 It is now possible to `step' and `next' through calls to `longjmp'.
7344 * Changes in documentation.
7346 All GDB documentation was converted to GFDL, the GNU Free
7347 Documentation License.
7349 Tracepoints-related commands are now fully documented in the GDB
7352 TUI, the Text-mode User Interface, is now documented in the manual.
7354 Tracepoints-related commands are now fully documented in the GDB
7357 The "GDB Internals" manual now has an index. It also includes
7358 documentation of `ui_out' functions, GDB coding standards, x86
7359 hardware watchpoints, and memory region attributes.
7361 * GDB's version number moved to ``version.in''
7363 The Makefile variable VERSION has been replaced by the file
7364 ``version.in''. People creating GDB distributions should update the
7365 contents of this file.
7369 GUD support is now a standard part of the EMACS distribution.
7371 *** Changes in GDB 5.0:
7373 * Improved support for debugging FP programs on x86 targets
7375 Unified and much-improved support for debugging floating-point
7376 programs on all x86 targets. In particular, ``info float'' now
7377 displays the FP registers in the same format on all x86 targets, with
7378 greater level of detail.
7380 * Improvements and bugfixes in hardware-assisted watchpoints
7382 It is now possible to watch array elements, struct members, and
7383 bitfields with hardware-assisted watchpoints. Data-read watchpoints
7384 on x86 targets no longer erroneously trigger when the address is
7387 * Improvements in the native DJGPP version of GDB
7389 The distribution now includes all the scripts and auxiliary files
7390 necessary to build the native DJGPP version on MS-DOS/MS-Windows
7391 machines ``out of the box''.
7393 The DJGPP version can now debug programs that use signals. It is
7394 possible to catch signals that happened in the debuggee, deliver
7395 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
7396 would kill the program being debugged.) Programs that hook hardware
7397 interrupts (keyboard, timer, etc.) can also be debugged.
7399 It is now possible to debug DJGPP programs that redirect their
7400 standard handles or switch them to raw (as opposed to cooked) mode, or
7401 even close them. The command ``run < foo > bar'' works as expected,
7402 and ``info terminal'' reports useful information about the debuggee's
7403 terminal, including raw/cooked mode, redirection, etc.
7405 The DJGPP version now uses termios functions for console I/O, which
7406 enables debugging graphics programs. Interrupting GDB with Ctrl-C
7409 DOS-style file names with drive letters are now fully supported by
7412 It is now possible to debug DJGPP programs that switch their working
7413 directory. It is also possible to rerun the debuggee any number of
7414 times without restarting GDB; thus, you can use the same setup,
7415 breakpoints, etc. for many debugging sessions.
7417 * New native configurations
7419 ARM GNU/Linux arm*-*-linux*
7420 PowerPC GNU/Linux powerpc-*-linux*
7424 Motorola MCore mcore-*-*
7425 x86 VxWorks i[3456]86-*-vxworks*
7426 PowerPC VxWorks powerpc-*-vxworks*
7427 TI TMS320C80 tic80-*-*
7429 * OBSOLETE configurations
7431 Altos 3068 m68*-altos-*
7432 Convex c1-*-*, c2-*-*
7434 ARM RISCix arm-*-* (as host)
7437 Configurations that have been declared obsolete will be commented out,
7438 but the code will be left in place. If there is no activity to revive
7439 these configurations before the next release of GDB, the sources will
7440 be permanently REMOVED.
7442 * Gould support removed
7444 Support for the Gould PowerNode and NP1 has been removed.
7446 * New features for SVR4
7448 On SVR4 native platforms (such as Solaris), if you attach to a process
7449 without first loading a symbol file, GDB will now attempt to locate and
7450 load symbols from the running process's executable file.
7452 * Many C++ enhancements
7454 C++ support has been greatly improved. Overload resolution now works properly
7455 in almost all cases. RTTI support is on the way.
7457 * Remote targets can connect to a sub-program
7459 A popen(3) style serial-device has been added. This device starts a
7460 sub-process (such as a stand-alone simulator) and then communicates
7461 with that. The sub-program to run is specified using the syntax
7462 ``|<program> <args>'' vis:
7464 (gdb) set remotedebug 1
7465 (gdb) target extended-remote |mn10300-elf-sim program-args
7467 * MIPS 64 remote protocol
7469 A long standing bug in the mips64 remote protocol where by GDB
7470 expected certain 32 bit registers (ex SR) to be transfered as 32
7471 instead of 64 bits has been fixed.
7473 The command ``set remote-mips64-transfers-32bit-regs on'' has been
7474 added to provide backward compatibility with older versions of GDB.
7476 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
7478 The command ``set remotebinarydownload'' command has been replaced by
7479 ``set remote X-packet''. Other commands in ``set remote'' family
7480 include ``set remote P-packet''.
7482 * Breakpoint commands accept ranges.
7484 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
7485 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
7486 ``tracepoint passcount'' also accepts a range of tracepoints.
7488 * ``apropos'' command added.
7490 The ``apropos'' command searches through command names and
7491 documentation strings, printing out matches, making it much easier to
7492 try to find a command that does what you are looking for.
7496 A new machine oriented interface (MI) has been added to GDB. This
7497 interface is designed for debug environments running GDB as a separate
7498 process. This is part of the long term libGDB project. See the
7499 "GDB/MI" chapter of the GDB manual for further information. It can be
7500 enabled by configuring with:
7502 .../configure --enable-gdbmi
7504 *** Changes in GDB-4.18:
7506 * New native configurations
7508 HP-UX 10.20 hppa*-*-hpux10.20
7509 HP-UX 11.x hppa*-*-hpux11.0*
7510 M68K GNU/Linux m68*-*-linux*
7514 Fujitsu FR30 fr30-*-elf*
7515 Intel StrongARM strongarm-*-*
7516 Mitsubishi D30V d30v-*-*
7518 * OBSOLETE configurations
7520 Gould PowerNode, NP1 np1-*-*, pn-*-*
7522 Configurations that have been declared obsolete will be commented out,
7523 but the code will be left in place. If there is no activity to revive
7524 these configurations before the next release of GDB, the sources will
7525 be permanently REMOVED.
7529 As a compatibility experiment, GDB's source files buildsym.h and
7530 buildsym.c have been converted to pure standard C, no longer
7531 containing any K&R compatibility code. We believe that all systems in
7532 use today either come with a standard C compiler, or have a GCC port
7533 available. If this is not true, please report the affected
7534 configuration to bug-gdb@gnu.org immediately. See the README file for
7535 information about getting a standard C compiler if you don't have one
7540 GDB now uses readline 2.2.
7542 * set extension-language
7544 You can now control the mapping between filename extensions and source
7545 languages by using the `set extension-language' command. For instance,
7546 you can ask GDB to treat .c files as C++ by saying
7547 set extension-language .c c++
7548 The command `info extensions' lists all of the recognized extensions
7549 and their associated languages.
7551 * Setting processor type for PowerPC and RS/6000
7553 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
7554 you can use the `set processor' command to specify what variant of the
7555 PowerPC family you are debugging. The command
7559 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
7560 following PowerPC and RS6000 variants:
7562 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
7563 rs6000 IBM RS6000 ("POWER") architecture, user-level view
7565 403GC IBM PowerPC 403GC
7566 505 Motorola PowerPC 505
7567 860 Motorola PowerPC 860 or 850
7568 601 Motorola PowerPC 601
7569 602 Motorola PowerPC 602
7570 603 Motorola/IBM PowerPC 603 or 603e
7571 604 Motorola PowerPC 604 or 604e
7572 750 Motorola/IBM PowerPC 750 or 750
7574 At the moment, this command just tells GDB what to name the
7575 special-purpose processor registers. Since almost all the affected
7576 registers are inaccessible to user-level programs, this command is
7577 only useful for remote debugging in its present form.
7581 Thanks to a major code donation from Hewlett-Packard, GDB now has much
7582 more extensive support for HP-UX. Added features include shared
7583 library support, kernel threads and hardware watchpoints for 11.00,
7584 support for HP's ANSI C and C++ compilers, and a compatibility mode
7585 for xdb and dbx commands.
7589 HP's donation includes the new concept of catchpoints, which is a
7590 generalization of the old catch command. On HP-UX, it is now possible
7591 to catch exec, fork, and vfork, as well as library loading.
7593 This means that the existing catch command has changed; its first
7594 argument now specifies the type of catch to be set up. See the
7595 output of "help catch" for a list of catchpoint types.
7597 * Debugging across forks
7599 On HP-UX, you can choose which process to debug when a fork() happens
7604 HP has donated a curses-based terminal user interface (TUI). To get
7605 it, build with --enable-tui. Although this can be enabled for any
7606 configuration, at present it only works for native HP debugging.
7608 * GDB remote protocol additions
7610 A new protocol packet 'X' that writes binary data is now available.
7611 Default behavior is to try 'X', then drop back to 'M' if the stub
7612 fails to respond. The settable variable `remotebinarydownload'
7613 allows explicit control over the use of 'X'.
7615 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
7616 full 64-bit address. The command
7618 set remoteaddresssize 32
7620 can be used to revert to the old behaviour. For existing remote stubs
7621 the change should not be noticed, as the additional address information
7624 In order to assist in debugging stubs, you may use the maintenance
7625 command `packet' to send any text string to the stub. For instance,
7627 maint packet heythere
7629 sends the packet "$heythere#<checksum>". Note that it is very easy to
7630 disrupt a debugging session by sending the wrong packet at the wrong
7633 The compare-sections command allows you to compare section data on the
7634 target to what is in the executable file without uploading or
7635 downloading, by comparing CRC checksums.
7637 * Tracing can collect general expressions
7639 You may now collect general expressions at tracepoints. This requires
7640 further additions to the target-side stub; see tracepoint.c and
7641 doc/agentexpr.texi for further details.
7643 * mask-address variable for Mips
7645 For Mips targets, you may control the zeroing of the upper 32 bits of
7646 a 64-bit address by entering `set mask-address on'. This is mainly
7647 of interest to users of embedded R4xxx and R5xxx processors.
7649 * Higher serial baud rates
7651 GDB's serial code now allows you to specify baud rates 57600, 115200,
7652 230400, and 460800 baud. (Note that your host system may not be able
7653 to achieve all of these rates.)
7657 The i960 configuration now includes an initial implementation of a
7658 builtin simulator, contributed by Jim Wilson.
7661 *** Changes in GDB-4.17:
7663 * New native configurations
7665 Alpha GNU/Linux alpha*-*-linux*
7666 Unixware 2.x i[3456]86-unixware2*
7667 Irix 6.x mips*-sgi-irix6*
7668 PowerPC GNU/Linux powerpc-*-linux*
7669 PowerPC Solaris powerpcle-*-solaris*
7670 Sparc GNU/Linux sparc-*-linux*
7671 Motorola sysV68 R3V7.1 m68k-motorola-sysv
7675 Argonaut Risc Chip (ARC) arc-*-*
7676 Hitachi H8/300S h8300*-*-*
7677 Matsushita MN10200 w/simulator mn10200-*-*
7678 Matsushita MN10300 w/simulator mn10300-*-*
7679 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
7680 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
7681 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
7682 Mitsubishi D10V w/simulator d10v-*-*
7683 Mitsubishi M32R/D w/simulator m32r-*-elf*
7684 Tsqware Sparclet sparclet-*-*
7685 NEC V850 w/simulator v850-*-*
7687 * New debugging protocols
7689 ARM with RDI protocol arm*-*-*
7690 M68K with dBUG monitor m68*-*-{aout,coff,elf}
7691 DDB and LSI variants of PMON protocol mips*-*-*
7692 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
7693 PowerPC with SDS protocol powerpc{,le}-*-eabi
7694 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
7698 All configurations can now understand and use the DWARF 2 debugging
7699 format. The choice is automatic, if the symbol file contains DWARF 2
7704 GDB now includes basic Java language support. This support is
7705 only useful with Java compilers that produce native machine code.
7707 * solib-absolute-prefix and solib-search-path
7709 For SunOS and SVR4 shared libraries, you may now set the prefix for
7710 loading absolute shared library symbol files, and the search path for
7711 locating non-absolute shared library symbol files.
7713 * Live range splitting
7715 GDB can now effectively debug code for which GCC has performed live
7716 range splitting as part of its optimization. See gdb/doc/LRS for
7717 more details on the expected format of the stabs information.
7721 GDB's support for the GNU Hurd, including thread debugging, has been
7722 updated to work with current versions of the Hurd.
7726 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
7727 instruction set. ARM GDB automatically detects when Thumb
7728 instructions are in use, and adjusts disassembly and backtracing
7733 GDB's MIPS target configurations now handle the MIP16 16-bit
7738 GDB now includes support for overlays; if an executable has been
7739 linked such that multiple sections are based at the same address, GDB
7740 will decide which section to use for symbolic info. You can choose to
7741 control the decision manually, using overlay commands, or implement
7742 additional target-side support and use "overlay load-target" to bring
7743 in the overlay mapping. Do "help overlay" for more detail.
7747 The command "info symbol <address>" displays information about
7748 the symbol at the specified address.
7752 The standard remote protocol now includes an extension that allows
7753 asynchronous collection and display of trace data. This requires
7754 extensive support in the target-side debugging stub. Tracing mode
7755 includes a new interaction mode in GDB and new commands: see the
7756 file tracepoint.c for more details.
7760 Configurations for embedded MIPS now include a simulator contributed
7761 by Cygnus Solutions. The simulator supports the instruction sets
7762 of most MIPS variants.
7766 Sparc configurations may now include the ERC32 simulator contributed
7767 by the European Space Agency. The simulator is not built into
7768 Sparc targets by default; configure with --enable-sim to include it.
7772 For target configurations that may include multiple variants of a
7773 basic architecture (such as MIPS and SH), you may now set the
7774 architecture explicitly. "set arch" sets, "info arch" lists
7775 the possible architectures.
7777 *** Changes in GDB-4.16:
7779 * New native configurations
7781 Windows 95, x86 Windows NT i[345]86-*-cygwin32
7782 M68K NetBSD m68k-*-netbsd*
7783 PowerPC AIX 4.x powerpc-*-aix*
7784 PowerPC MacOS powerpc-*-macos*
7785 PowerPC Windows NT powerpcle-*-cygwin32
7786 RS/6000 AIX 4.x rs6000-*-aix4*
7790 ARM with RDP protocol arm-*-*
7791 I960 with MON960 i960-*-coff
7792 MIPS VxWorks mips*-*-vxworks*
7793 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
7794 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
7796 Matra Sparclet sparclet-*-*
7800 The powerpc-eabi configuration now includes the PSIM simulator,
7801 contributed by Andrew Cagney, with assistance from Mike Meissner.
7802 PSIM is a very elaborate model of the PowerPC, including not only
7803 basic instruction set execution, but also details of execution unit
7804 performance and I/O hardware. See sim/ppc/README for more details.
7808 GDB now works with Solaris 2.5.
7810 * Windows 95/NT native
7812 GDB will now work as a native debugger on Windows 95 and Windows NT.
7813 To build it from source, you must use the "gnu-win32" environment,
7814 which uses a DLL to emulate enough of Unix to run the GNU tools.
7815 Further information, binaries, and sources are available at
7816 ftp.cygnus.com, under pub/gnu-win32.
7818 * dont-repeat command
7820 If a user-defined command includes the command `dont-repeat', then the
7821 command will not be repeated if the user just types return. This is
7822 useful if the command is time-consuming to run, so that accidental
7823 extra keystrokes don't run the same command many times.
7825 * Send break instead of ^C
7827 The standard remote protocol now includes an option to send a break
7828 rather than a ^C to the target in order to interrupt it. By default,
7829 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
7831 * Remote protocol timeout
7833 The standard remote protocol includes a new variable `remotetimeout'
7834 that allows you to set the number of seconds before GDB gives up trying
7835 to read from the target. The default value is 2.
7837 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
7839 By default GDB will automatically keep track of objects as they are
7840 loaded and unloaded by the dynamic linker. By using the command `set
7841 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
7842 when shared library events occur, thus allowing you to set breakpoints
7843 in shared libraries which are explicitly loaded by the inferior.
7845 Note this feature does not work on hpux8. On hpux9 you must link
7846 /usr/lib/end.o into your program. This feature should work
7847 automatically on hpux10.
7849 * Irix 5.x hardware watchpoint support
7851 Irix 5 configurations now support the use of hardware watchpoints.
7853 * Mips protocol "SYN garbage limit"
7855 When debugging a Mips target using the `target mips' protocol, you
7856 may set the number of characters that GDB will ignore by setting
7857 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
7858 every character. The default value is 1050.
7860 * Recording and replaying remote debug sessions
7862 If you set `remotelogfile' to the name of a file, gdb will write to it
7863 a recording of a remote debug session. This recording may then be
7864 replayed back to gdb using "gdbreplay". See gdbserver/README for
7865 details. This is useful when you have a problem with GDB while doing
7866 remote debugging; you can make a recording of the session and send it
7867 to someone else, who can then recreate the problem.
7869 * Speedups for remote debugging
7871 GDB includes speedups for downloading and stepping MIPS systems using
7872 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
7873 and more efficient S-record downloading.
7875 * Memory use reductions and statistics collection
7877 GDB now uses less memory and reports statistics about memory usage.
7878 Try the `maint print statistics' command, for example.
7880 *** Changes in GDB-4.15:
7882 * Psymtabs for XCOFF
7884 The symbol reader for AIX GDB now uses partial symbol tables. This
7885 can greatly improve startup time, especially for large executables.
7887 * Remote targets use caching
7889 Remote targets now use a data cache to speed up communication with the
7890 remote side. The data cache could lead to incorrect results because
7891 it doesn't know about volatile variables, thus making it impossible to
7892 debug targets which use memory mapped I/O devices. `set remotecache
7893 off' turns the data cache off.
7895 * Remote targets may have threads
7897 The standard remote protocol now includes support for multiple threads
7898 in the target system, using new protocol commands 'H' and 'T'. See
7899 gdb/remote.c for details.
7903 If GDB is configured with `--enable-netrom', then it will include
7904 support for the NetROM ROM emulator from XLNT Designs. The NetROM
7905 acts as though it is a bank of ROM on the target board, but you can
7906 write into it over the network. GDB's support consists only of
7907 support for fast loading into the emulated ROM; to debug, you must use
7908 another protocol, such as standard remote protocol. The usual
7909 sequence is something like
7911 target nrom <netrom-hostname>
7913 target remote <netrom-hostname>:1235
7917 GDB now includes support for the Apple Macintosh, as a host only. It
7918 may be run as either an MPW tool or as a standalone application, and
7919 it can debug through the serial port. All the usual GDB commands are
7920 available, but to the target command, you must supply "serial" as the
7921 device type instead of "/dev/ttyXX". See mpw-README in the main
7922 directory for more information on how to build. The MPW configuration
7923 scripts */mpw-config.in support only a few targets, and only the
7924 mips-idt-ecoff target has been tested.
7928 GDB configuration now uses autoconf. This is not user-visible,
7929 but does simplify configuration and building.
7933 GDB now supports hpux10.
7935 *** Changes in GDB-4.14:
7937 * New native configurations
7939 x86 FreeBSD i[345]86-*-freebsd
7940 x86 NetBSD i[345]86-*-netbsd
7941 NS32k NetBSD ns32k-*-netbsd
7942 Sparc NetBSD sparc-*-netbsd
7946 A29K VxWorks a29k-*-vxworks
7947 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
7948 CPU32 EST-300 emulator m68*-*-est*
7949 PowerPC ELF powerpc-*-elf
7952 * Alpha OSF/1 support for procfs
7954 GDB now supports procfs under OSF/1-2.x and higher, which makes it
7955 possible to attach to running processes. As the mounting of the /proc
7956 filesystem is optional on the Alpha, GDB automatically determines
7957 the availability of /proc during startup. This can lead to problems
7958 if /proc is unmounted after GDB has been started.
7960 * Arguments to user-defined commands
7962 User commands may accept up to 10 arguments separated by whitespace.
7963 Arguments are accessed within the user command via $arg0..$arg9. A
7966 print $arg0 + $arg1 + $arg2
7968 To execute the command use:
7971 Defines the command "adder" which prints the sum of its three arguments.
7972 Note the arguments are text substitutions, so they may reference variables,
7973 use complex expressions, or even perform inferior function calls.
7975 * New `if' and `while' commands
7977 This makes it possible to write more sophisticated user-defined
7978 commands. Both commands take a single argument, which is the
7979 expression to evaluate, and must be followed by the commands to
7980 execute, one per line, if the expression is nonzero, the list being
7981 terminated by the word `end'. The `if' command list may include an
7982 `else' word, which causes the following commands to be executed only
7983 if the expression is zero.
7985 * Fortran source language mode
7987 GDB now includes partial support for Fortran 77. It will recognize
7988 Fortran programs and can evaluate a subset of Fortran expressions, but
7989 variables and functions may not be handled correctly. GDB will work
7990 with G77, but does not yet know much about symbols emitted by other
7993 * Better HPUX support
7995 Most debugging facilities now work on dynamic executables for HPPAs
7996 running hpux9 or later. You can attach to running dynamically linked
7997 processes, but by default the dynamic libraries will be read-only, so
7998 for instance you won't be able to put breakpoints in them. To change
7999 that behavior do the following before running the program:
8005 This will cause the libraries to be mapped private and read-write.
8006 To revert to the normal behavior, do this:
8012 You cannot set breakpoints or examine data in the library until after
8013 the library is loaded if the function/data symbols do not have
8016 GDB can now also read debug symbols produced by the HP C compiler on
8017 HPPAs (sorry, no C++, Fortran or 68k support).
8019 * Target byte order now dynamically selectable
8021 You can choose which byte order to use with a target system, via the
8022 commands "set endian big" and "set endian little", and you can see the
8023 current setting by using "show endian". You can also give the command
8024 "set endian auto", in which case GDB will use the byte order
8025 associated with the executable. Currently, only embedded MIPS
8026 configurations support dynamic selection of target byte order.
8028 * New DOS host serial code
8030 This version uses DPMI interrupts to handle buffered I/O, so you
8031 no longer need to run asynctsr when debugging boards connected to
8034 *** Changes in GDB-4.13:
8036 * New "complete" command
8038 This lists all the possible completions for the rest of the line, if it
8039 were to be given as a command itself. This is intended for use by emacs.
8041 * Trailing space optional in prompt
8043 "set prompt" no longer adds a space for you after the prompt you set. This
8044 allows you to set a prompt which ends in a space or one that does not.
8046 * Breakpoint hit counts
8048 "info break" now displays a count of the number of times the breakpoint
8049 has been hit. This is especially useful in conjunction with "ignore"; you
8050 can ignore a large number of breakpoint hits, look at the breakpoint info
8051 to see how many times the breakpoint was hit, then run again, ignoring one
8052 less than that number, and this will get you quickly to the last hit of
8055 * Ability to stop printing at NULL character
8057 "set print null-stop" will cause GDB to stop printing the characters of
8058 an array when the first NULL is encountered. This is useful when large
8059 arrays actually contain only short strings.
8061 * Shared library breakpoints
8063 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
8064 breakpoints in shared libraries before the executable is run.
8066 * Hardware watchpoints
8068 There is a new hardware breakpoint for the watch command for sparclite
8069 targets. See gdb/sparclite/hw_breakpoint.note.
8071 Hardware watchpoints are also now supported under GNU/Linux.
8075 Annotations have been added. These are for use with graphical interfaces,
8076 and are still experimental. Currently only gdba.el uses these.
8078 * Improved Irix 5 support
8080 GDB now works properly with Irix 5.2.
8082 * Improved HPPA support
8084 GDB now works properly with the latest GCC and GAS.
8086 * New native configurations
8088 Sequent PTX4 i[34]86-sequent-ptx4
8089 HPPA running OSF/1 hppa*-*-osf*
8090 Atari TT running SVR4 m68*-*-sysv4*
8091 RS/6000 LynxOS rs6000-*-lynxos*
8095 OS/9000 i[34]86-*-os9k
8096 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
8099 * Hitachi SH7000 and E7000-PC ICE support
8101 There is now support for communicating with the Hitachi E7000-PC ICE.
8102 This is available automatically when GDB is configured for the SH.
8106 As usual, a variety of small fixes and improvements, both generic
8107 and configuration-specific. See the ChangeLog for more detail.
8109 *** Changes in GDB-4.12:
8111 * Irix 5 is now supported
8115 GDB-4.12 on the HPPA has a number of changes which make it unable
8116 to debug the output from the currently released versions of GCC and
8117 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
8118 of GCC and GAS, versions of these tools designed to work with GDB-4.12
8119 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
8122 *** Changes in GDB-4.11:
8124 * User visible changes:
8128 The "set remotedebug" option is now consistent between the mips remote
8129 target, remote targets using the gdb-specific protocol, UDI (AMD's
8130 debug protocol for the 29k) and the 88k bug monitor. It is now an
8131 integer specifying a debug level (normally 0 or 1, but 2 means more
8132 debugging info for the mips target).
8134 * DEC Alpha native support
8136 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
8137 debug info, but GDB works fairly well with the DEC compiler and should
8138 work with a future GCC release. See the README file for a few
8139 Alpha-specific notes.
8141 * Preliminary thread implementation
8143 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
8145 * LynxOS native and target support for 386
8147 This release has been hosted on LynxOS 2.2, and also can be configured
8148 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
8151 * Improvements in C++ mangling/demangling.
8153 This release has much better g++ debugging, specifically in name
8154 mangling/demangling, virtual function calls, print virtual table,
8155 call methods, ...etc.
8157 *** Changes in GDB-4.10:
8159 * User visible changes:
8161 Remote debugging using the GDB-specific (`target remote') protocol now
8162 supports the `load' command. This is only useful if you have some
8163 other way of getting the stub to the target system, and you can put it
8164 somewhere in memory where it won't get clobbered by the download.
8166 Filename completion now works.
8168 When run under emacs mode, the "info line" command now causes the
8169 arrow to point to the line specified. Also, "info line" prints
8170 addresses in symbolic form (as well as hex).
8172 All vxworks based targets now support a user settable option, called
8173 vxworks-timeout. This option represents the number of seconds gdb
8174 should wait for responses to rpc's. You might want to use this if
8175 your vxworks target is, perhaps, a slow software simulator or happens
8176 to be on the far side of a thin network line.
8180 This release contains support for using a DEC alpha as a GDB host for
8181 cross debugging. Native alpha debugging is not supported yet.
8184 *** Changes in GDB-4.9:
8188 This is the first GDB release which is accompanied by a matching testsuite.
8189 The testsuite requires installation of dejagnu, which should be available
8190 via ftp from most sites that carry GNU software.
8194 'Cfront' style demangling has had its name changed to 'ARM' style, to
8195 emphasize that it was written from the specifications in the C++ Annotated
8196 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
8197 disclaimers, it still generated too much confusion with users attempting to
8198 use gdb with AT&T cfront.
8202 GDB now uses a standard remote interface to a simulator library.
8203 So far, the library contains simulators for the Zilog Z8001/2, the
8204 Hitachi H8/300, H8/500 and Super-H.
8206 * New targets supported
8208 H8/300 simulator h8300-hitachi-hms or h8300hms
8209 H8/500 simulator h8500-hitachi-hms or h8500hms
8210 SH simulator sh-hitachi-hms or sh
8211 Z8000 simulator z8k-zilog-none or z8ksim
8212 IDT MIPS board over serial line mips-idt-ecoff
8214 Cross-debugging to GO32 targets is supported. It requires a custom
8215 version of the i386-stub.c module which is integrated with the
8216 GO32 memory extender.
8218 * New remote protocols
8220 MIPS remote debugging protocol.
8222 * New source languages supported
8224 This version includes preliminary support for Chill, a Pascal like language
8225 used by telecommunications companies. Chill support is also being integrated
8226 into the GNU compiler, but we don't know when it will be publically available.
8229 *** Changes in GDB-4.8:
8231 * HP Precision Architecture supported
8233 GDB now supports HP PA-RISC machines running HPUX. A preliminary
8234 version of this support was available as a set of patches from the
8235 University of Utah. GDB does not support debugging of programs
8236 compiled with the HP compiler, because HP will not document their file
8237 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
8238 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
8240 Many problems in the preliminary version have been fixed.
8242 * Faster and better demangling
8244 We have improved template demangling and fixed numerous bugs in the GNU style
8245 demangler. It can now handle type modifiers such as `static' or `const'. Wide
8246 character types (wchar_t) are now supported. Demangling of each symbol is now
8247 only done once, and is cached when the symbol table for a file is read in.
8248 This results in a small increase in memory usage for C programs, a moderate
8249 increase in memory usage for C++ programs, and a fantastic speedup in
8252 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
8253 from the specifications in the Annotated Reference Manual, which AT&T's
8254 compiler does not actually implement.
8256 * G++ multiple inheritance compiler problem
8258 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
8259 inheritance lattices was reworked to properly discover ambiguities. We
8260 recently found an example which causes this new algorithm to fail in a
8261 very subtle way, producing bad debug information for those classes.
8262 The file 'gcc.patch' (in this directory) can be applied to gcc to
8263 circumvent the problem. A future GCC release will contain a complete
8266 The previous G++ debug info problem (mentioned below for the gdb-4.7
8267 release) is fixed in gcc version 2.3.2.
8269 * Improved configure script
8271 The `configure' script will now attempt to guess your system type if
8272 you don't supply a host system type. The old scheme of supplying a
8273 host system triplet is preferable over using this. All the magic is
8274 done in the new `config.guess' script. Examine it for details.
8276 We have also brought our configure script much more in line with the FSF's
8277 version. It now supports the --with-xxx options. In particular,
8278 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
8279 The resulting GDB will not be able to read arbitrary object file formats --
8280 only the format ``expected'' to be used on the configured target system.
8281 We hope to make this the default in a future release.
8283 * Documentation improvements
8285 There's new internal documentation on how to modify GDB, and how to
8286 produce clean changes to the code. We implore people to read it
8287 before submitting changes.
8289 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
8290 M4 macros. The new texinfo.tex is provided in this release. Pre-built
8291 `info' files are also provided. To build `info' files from scratch,
8292 you will need the latest `makeinfo' release, which will be available in
8293 a future texinfo-X.Y release.
8295 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
8296 We're not sure exactly which versions have this problem, but it has
8297 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
8298 or better. If that isn't possible, there is a patch in
8299 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
8300 around this problem.
8304 GDB now supports array constants that can be used in expressions typed in by
8305 the user. The syntax is `{element, element, ...}'. Ie: you can now type
8306 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
8309 The new directory `gdb/sparclite' contains a program that demonstrates
8310 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
8312 * New native hosts supported
8314 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
8315 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
8317 * New targets supported
8319 AMD 29k family via UDI a29k-amd-udi or udi29k
8321 * New file formats supported
8323 BFD now supports reading HP/PA-RISC executables (SOM file format?),
8324 HPUX core files, and SCO 3.2v2 core files.
8328 Attaching to processes now works again; thanks for the many bug reports.
8330 We have also stomped on a bunch of core dumps caused by
8331 printf_filtered("%s") problems.
8333 We eliminated a copyright problem on the rpc and ptrace header files
8334 for VxWorks, which was discovered at the last minute during the 4.7
8335 release. You should now be able to build a VxWorks GDB.
8337 You can now interrupt gdb while an attached process is running. This
8338 will cause the attached process to stop, and give control back to GDB.
8340 We fixed problems caused by using too many file descriptors
8341 for reading symbols from object files and libraries. This was
8342 especially a problem for programs that used many (~100) shared
8345 The `step' command now only enters a subroutine if there is line number
8346 information for the subroutine. Otherwise it acts like the `next'
8347 command. Previously, `step' would enter subroutines if there was
8348 any debugging information about the routine. This avoids problems
8349 when using `cc -g1' on MIPS machines.
8351 * Internal improvements
8353 GDB's internal interfaces have been improved to make it easier to support
8354 debugging of multiple languages in the future.
8356 GDB now uses a common structure for symbol information internally.
8357 Minimal symbols (derived from linkage symbols in object files), partial
8358 symbols (from a quick scan of debug information), and full symbols
8359 contain a common subset of information, making it easier to write
8360 shared code that handles any of them.
8362 * New command line options
8364 We now accept --silent as an alias for --quiet.
8368 The memory-mapped-malloc library is now licensed under the GNU Library
8369 General Public License.
8371 *** Changes in GDB-4.7:
8373 * Host/native/target split
8375 GDB has had some major internal surgery to untangle the support for
8376 hosts and remote targets. Now, when you configure GDB for a remote
8377 target, it will no longer load in all of the support for debugging
8378 local programs on the host. When fully completed and tested, this will
8379 ensure that arbitrary host/target combinations are possible.
8381 The primary conceptual shift is to separate the non-portable code in
8382 GDB into three categories. Host specific code is required any time GDB
8383 is compiled on that host, regardless of the target. Target specific
8384 code relates to the peculiarities of the target, but can be compiled on
8385 any host. Native specific code is everything else: it can only be
8386 built when the host and target are the same system. Child process
8387 handling and core file support are two common `native' examples.
8389 GDB's use of /proc for controlling Unix child processes is now cleaner.
8390 It has been split out into a single module under the `target_ops' vector,
8391 plus two native-dependent functions for each system that uses /proc.
8393 * New hosts supported
8395 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
8396 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8397 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
8399 * New targets supported
8401 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
8402 68030 and CPU32 m68030-*-*, m68332-*-*
8404 * New native hosts supported
8406 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
8407 (386bsd is not well tested yet)
8408 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
8410 * New file formats supported
8412 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
8413 supports reading of `a.out.adobe' object files, which are an a.out
8414 format extended with minimal information about multiple sections.
8418 `show copying' is the same as the old `info copying'.
8419 `show warranty' is the same as `info warrantee'.
8420 These were renamed for consistency. The old commands continue to work.
8422 `info handle' is a new alias for `info signals'.
8424 You can now define pre-command hooks, which attach arbitrary command
8425 scripts to any command. The commands in the hook will be executed
8426 prior to the user's command. You can also create a hook which will be
8427 executed whenever the program stops. See gdb.texinfo.
8431 We now deal with Cfront style name mangling, and can even extract type
8432 info from mangled symbols. GDB can automatically figure out which
8433 symbol mangling style your C++ compiler uses.
8435 Calling of methods and virtual functions has been improved as well.
8439 The crash that occurred when debugging Sun Ansi-C compiled binaries is
8440 fixed. This was due to mishandling of the extra N_SO stabs output
8443 We also finally got Ultrix 4.2 running in house, and fixed core file
8444 support, with help from a dozen people on the net.
8446 John M. Farrell discovered that the reason that single-stepping was so
8447 slow on all of the Mips based platforms (primarily SGI and DEC) was
8448 that we were trying to demangle and lookup a symbol used for internal
8449 purposes on every instruction that was being stepped through. Changing
8450 the name of that symbol so that it couldn't be mistaken for a C++
8451 mangled symbol sped things up a great deal.
8453 Rich Pixley sped up symbol lookups in general by getting much smarter
8454 about when C++ symbol mangling is necessary. This should make symbol
8455 completion (TAB on the command line) much faster. It's not as fast as
8456 we'd like, but it's significantly faster than gdb-4.6.
8460 A new user controllable variable 'call_scratch_address' can
8461 specify the location of a scratch area to be used when GDB
8462 calls a function in the target. This is necessary because the
8463 usual method of putting the scratch area on the stack does not work
8464 in systems that have separate instruction and data spaces.
8466 We integrated changes to support the 29k UDI (Universal Debugger
8467 Interface), but discovered at the last minute that we didn't have all
8468 of the appropriate copyright paperwork. We are working with AMD to
8469 resolve this, and hope to have it available soon.
8473 We have sped up the remote serial line protocol, especially for targets
8474 with lots of registers. It now supports a new `expedited status' ('T')
8475 message which can be used in place of the existing 'S' status message.
8476 This allows the remote stub to send only the registers that GDB
8477 needs to make a quick decision about single-stepping or conditional
8478 breakpoints, eliminating the need to fetch the entire register set for
8479 each instruction being stepped through.
8481 The GDB remote serial protocol now implements a write-through cache for
8482 registers, only re-reading the registers if the target has run.
8484 There is also a new remote serial stub for SPARC processors. You can
8485 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
8486 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
8487 processor with a serial port.
8491 Configure.in files have become much easier to read and modify. A new
8492 `table driven' format makes it more obvious what configurations are
8493 supported, and what files each one uses.
8497 There is a new opcodes library which will eventually contain all of the
8498 disassembly routines and opcode tables. At present, it only contains
8499 Sparc and Z8000 routines. This will allow the assembler, debugger, and
8500 disassembler (binutils/objdump) to share these routines.
8502 The libiberty library is now copylefted under the GNU Library General
8503 Public License. This allows more liberal use, and was done so libg++
8504 can use it. This makes no difference to GDB, since the Library License
8505 grants all the rights from the General Public License.
8509 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
8510 reference to the stabs symbol info used by the debugger. It is (as far
8511 as we know) the only published document on this fascinating topic. We
8512 encourage you to read it, compare it to the stabs information on your
8513 system, and send improvements on the document in general (to
8514 bug-gdb@prep.ai.mit.edu).
8516 And, of course, many bugs have been fixed.
8519 *** Changes in GDB-4.6:
8521 * Better support for C++ function names
8523 GDB now accepts as input the "demangled form" of C++ overloaded function
8524 names and member function names, and can do command completion on such names
8525 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
8526 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
8527 Make use of command completion, it is your friend.
8529 GDB also now accepts a variety of C++ mangled symbol formats. They are
8530 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
8531 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
8532 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
8533 for the list of formats.
8535 * G++ symbol mangling problem
8537 Recent versions of gcc have a bug in how they emit debugging information for
8538 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
8539 directory) can be applied to gcc to fix the problem. Alternatively, if you
8540 can't fix gcc, you can #define GCC_MANGLE_BUG when compiling gdb/symtab.c. The
8541 usual symptom is difficulty with setting breakpoints on methods. GDB complains
8542 about the method being non-existent. (We believe that version 2.2.2 of GCC has
8545 * New 'maintenance' command
8547 All of the commands related to hacking GDB internals have been moved out of
8548 the main command set, and now live behind the 'maintenance' command. This
8549 can also be abbreviated as 'mt'. The following changes were made:
8551 dump-me -> maintenance dump-me
8552 info all-breakpoints -> maintenance info breakpoints
8553 printmsyms -> maintenance print msyms
8554 printobjfiles -> maintenance print objfiles
8555 printpsyms -> maintenance print psymbols
8556 printsyms -> maintenance print symbols
8558 The following commands are new:
8560 maintenance demangle Call internal GDB demangler routine to
8561 demangle a C++ link name and prints the result.
8562 maintenance print type Print a type chain for a given symbol
8564 * Change to .gdbinit file processing
8566 We now read the $HOME/.gdbinit file before processing the argv arguments
8567 (e.g. reading symbol files or core files). This allows global parameters to
8568 be set, which will apply during the symbol reading. The ./.gdbinit is still
8569 read after argv processing.
8571 * New hosts supported
8573 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
8575 GNU/Linux support i386-unknown-linux or linux
8577 We are also including code to support the HP/PA running BSD and HPUX. This
8578 is almost guaranteed not to work, as we didn't have time to test or build it
8579 for this release. We are including it so that the more adventurous (or
8580 masochistic) of you can play with it. We also had major problems with the
8581 fact that the compiler that we got from HP doesn't support the -g option.
8584 * New targets supported
8586 Hitachi H8/300 h8300-hitachi-hms or h8300hms
8588 * More smarts about finding #include files
8590 GDB now remembers the compilation directory for all include files, and for
8591 all files from which C is generated (like yacc and lex sources). This
8592 greatly improves GDB's ability to find yacc/lex sources, and include files,
8593 especially if you are debugging your program from a directory different from
8594 the one that contains your sources.
8596 We also fixed a bug which caused difficulty with listing and setting
8597 breakpoints in include files which contain C code. (In the past, you had to
8598 try twice in order to list an include file that you hadn't looked at before.)
8600 * Interesting infernals change
8602 GDB now deals with arbitrary numbers of sections, where the symbols for each
8603 section must be relocated relative to that section's landing place in the
8604 target's address space. This work was needed to support ELF with embedded
8605 stabs used by Solaris-2.0.
8607 * Bug fixes (of course!)
8609 There have been loads of fixes for the following things:
8610 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
8611 i960, stabs, DOS(GO32), procfs, etc...
8613 See the ChangeLog for details.
8615 *** Changes in GDB-4.5:
8617 * New machines supported (host and target)
8619 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
8621 SGI Irix-4.x mips-sgi-irix4 or iris4
8623 * New malloc package
8625 GDB now uses a new memory manager called mmalloc, based on gmalloc.
8626 Mmalloc is capable of handling multiple heaps of memory. It is also
8627 capable of saving a heap to a file, and then mapping it back in later.
8628 This can be used to greatly speedup the startup of GDB by using a
8629 pre-parsed symbol table which lives in a mmalloc managed heap. For
8630 more details, please read mmalloc/mmalloc.texi.
8634 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
8635 'help info proc' for details.
8637 * MIPS ecoff symbol table format
8639 The code that reads MIPS symbol table format is now supported on all hosts.
8640 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
8643 * File name changes for MS-DOS
8645 Many files in the config directories have been renamed to make it easier to
8646 support GDB on MS-DOSe systems (which have very restrictive file name
8647 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
8648 environment) is close to working but has some remaining problems. Note
8649 that debugging of DOS programs is not supported, due to limitations
8650 in the ``operating system'', but it can be used to host cross-debugging.
8652 * Cross byte order fixes
8654 Many fixes have been made to support cross debugging of Sparc and MIPS
8655 targets from hosts whose byte order differs.
8657 * New -mapped and -readnow options
8659 If memory-mapped files are available on your system through the 'mmap'
8660 system call, you can use the -mapped option on the `file' or
8661 `symbol-file' commands to cause GDB to write the symbols from your
8662 program into a reusable file. If the program you are debugging is
8663 called `/path/fred', the mapped symbol file will be `./fred.syms'.
8664 Future GDB debugging sessions will notice the presence of this file,
8665 and will quickly map in symbol information from it, rather than reading
8666 the symbol table from the executable program. Using the '-mapped'
8667 option in a GDB `file' or `symbol-file' command has the same effect as
8668 starting GDB with the '-mapped' command-line option.
8670 You can cause GDB to read the entire symbol table immediately by using
8671 the '-readnow' option with any of the commands that load symbol table
8672 information (or on the GDB command line). This makes the command
8673 slower, but makes future operations faster.
8675 The -mapped and -readnow options are typically combined in order to
8676 build a `fred.syms' file that contains complete symbol information.
8677 A simple GDB invocation to do nothing but build a `.syms' file for future
8680 gdb -batch -nx -mapped -readnow programname
8682 The `.syms' file is specific to the host machine on which GDB is run.
8683 It holds an exact image of GDB's internal symbol table. It cannot be
8684 shared across multiple host platforms.
8686 * longjmp() handling
8688 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
8689 siglongjmp() without losing control. This feature has not yet been ported to
8690 all systems. It currently works on many 386 platforms, all MIPS-based
8691 platforms (SGI, DECstation, etc), and Sun3/4.
8695 Preliminary work has been put in to support the new Solaris OS from Sun. At
8696 this time, it can control and debug processes, but it is not capable of
8701 As always, many many bug fixes. The major areas were with g++, and mipsread.
8702 People using the MIPS-based platforms should experience fewer mysterious
8703 crashes and trashed symbol tables.
8705 *** Changes in GDB-4.4:
8707 * New machines supported (host and target)
8709 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8711 BSD Reno on Vax vax-dec-bsd
8712 Ultrix on Vax vax-dec-ultrix
8714 * New machines supported (target)
8716 AMD 29000 embedded, using EBMON a29k-none-none
8720 GDB continues to improve its handling of C++. `References' work better.
8721 The demangler has also been improved, and now deals with symbols mangled as
8722 per the Annotated C++ Reference Guide.
8724 GDB also now handles `stabs' symbol information embedded in MIPS
8725 `ecoff' symbol tables. Since the ecoff format was not easily
8726 extensible to handle new languages such as C++, this appeared to be a
8727 good way to put C++ debugging info into MIPS binaries. This option
8728 will be supported in the GNU C compiler, version 2, when it is
8731 * New features for SVR4
8733 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
8734 shared libraries. Debugging dynamically linked programs should present
8735 only minor differences from debugging statically linked programs.
8737 The `info proc' command will print out information about any process
8738 on an SVR4 system (including the one you are debugging). At the moment,
8739 it prints the address mappings of the process.
8741 If you bring up GDB on another SVR4 system, please send mail to
8742 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
8744 * Better dynamic linking support in SunOS
8746 Reading symbols from shared libraries which contain debugging symbols
8747 now works properly. However, there remain issues such as automatic
8748 skipping of `transfer vector' code during function calls, which
8749 make it harder to debug code in a shared library, than to debug the
8750 same code linked statically.
8754 GDB is now using the latest `getopt' routines from the FSF. This
8755 version accepts the -- prefix for options with long names. GDB will
8756 continue to accept the old forms (-option and +option) as well.
8757 Various single letter abbreviations for options have been explicity
8758 added to the option table so that they won't get overshadowed in the
8759 future by other options that begin with the same letter.
8763 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
8764 Many assorted bugs have been handled. Many more remain to be handled.
8765 See the various ChangeLog files (primarily in gdb and bfd) for details.
8768 *** Changes in GDB-4.3:
8770 * New machines supported (host and target)
8772 Amiga 3000 running Amix m68k-cbm-svr4 or amix
8773 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
8774 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
8776 * Almost SCO Unix support
8778 We had hoped to support:
8779 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
8780 (except for core file support), but we discovered very late in the release
8781 that it has problems with process groups that render gdb unusable. Sorry
8782 about that. I encourage people to fix it and post the fixes.
8784 * Preliminary ELF and DWARF support
8786 GDB can read ELF object files on System V Release 4, and can handle
8787 debugging records for C, in DWARF format, in ELF files. This support
8788 is preliminary. If you bring up GDB on another SVR4 system, please
8789 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
8794 GDB now uses the latest `readline' library. One user-visible change
8795 is that two tabs will list possible command completions, which previously
8796 required typing M-? (meta-question mark, or ESC ?).
8800 The `stepi' bug that many of you noticed has been squashed.
8801 Many bugs in C++ have been handled. Many more remain to be handled.
8802 See the various ChangeLog files (primarily in gdb and bfd) for details.
8804 * State of the MIPS world (in case you wondered):
8806 GDB can understand the symbol tables emitted by the compilers
8807 supplied by most vendors of MIPS-based machines, including DEC. These
8808 symbol tables are in a format that essentially nobody else uses.
8810 Some versions of gcc come with an assembler post-processor called
8811 mips-tfile. This program is required if you want to do source-level
8812 debugging of gcc-compiled programs. I believe FSF does not ship
8813 mips-tfile with gcc version 1, but it will eventually come with gcc
8816 Debugging of g++ output remains a problem. g++ version 1.xx does not
8817 really support it at all. (If you're lucky, you should be able to get
8818 line numbers and stack traces to work, but no parameters or local
8819 variables.) With some work it should be possible to improve the
8822 When gcc version 2 is released, you will have somewhat better luck.
8823 However, even then you will get confusing results for inheritance and
8826 We will eventually provide full debugging of g++ output on
8827 DECstations. This will probably involve some kind of stabs-in-ecoff
8828 encapulation, but the details have not been worked out yet.
8831 *** Changes in GDB-4.2:
8833 * Improved configuration
8835 Only one copy of `configure' exists now, and it is not self-modifying.
8836 Porting BFD is simpler.
8840 The `step' and `next' commands now only stop at the first instruction
8841 of a source line. This prevents the multiple stops that used to occur
8842 in switch statements, for-loops, etc. `Step' continues to stop if a
8843 function that has debugging information is called within the line.
8847 Lots of small bugs fixed. More remain.
8849 * New host supported (not target)
8851 Intel 386 PC clone running Mach i386-none-mach
8854 *** Changes in GDB-4.1:
8856 * Multiple source language support
8858 GDB now has internal scaffolding to handle several source languages.
8859 It determines the type of each source file from its filename extension,
8860 and will switch expression parsing and number formatting to match the
8861 language of the function in the currently selected stack frame.
8862 You can also specifically set the language to be used, with
8863 `set language c' or `set language modula-2'.
8867 GDB now has preliminary support for the GNU Modula-2 compiler,
8868 currently under development at the State University of New York at
8869 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
8870 continue through the fall of 1991 and into 1992.
8872 Other Modula-2 compilers are currently not supported, and attempting to
8873 debug programs compiled with them will likely result in an error as the
8874 symbol table is read. Feel free to work on it, though!
8876 There are hooks in GDB for strict type checking and range checking,
8877 in the `Modula-2 philosophy', but they do not currently work.
8881 GDB can now write to executable and core files (e.g. patch
8882 a variable's value). You must turn this switch on, specify
8883 the file ("exec foo" or "core foo"), *then* modify it, e.g.
8884 by assigning a new value to a variable. Modifications take
8887 * Automatic SunOS shared library reading
8889 When you run your program, GDB automatically determines where its
8890 shared libraries (if any) have been loaded, and reads their symbols.
8891 The `share' command is no longer needed. This also works when
8892 examining core files.
8896 You can specify the number of lines that the `list' command shows.
8899 * New machines supported (host and target)
8901 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
8902 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
8903 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
8905 * New hosts supported (not targets)
8907 IBM RT/PC: romp-ibm-aix or rtpc
8909 * New targets supported (not hosts)
8911 AMD 29000 embedded with COFF a29k-none-coff
8912 AMD 29000 embedded with a.out a29k-none-aout
8913 Ultracomputer remote kernel debug a29k-nyu-kern
8915 * New remote interfaces
8921 *** Changes in GDB-4.0:
8925 Wide output is wrapped at good places to make the output more readable.
8927 Gdb now supports cross-debugging from a host machine of one type to a
8928 target machine of another type. Communication with the target system
8929 is over serial lines. The ``target'' command handles connecting to the
8930 remote system; the ``load'' command will download a program into the
8931 remote system. Serial stubs for the m68k and i386 are provided. Gdb
8932 also supports debugging of realtime processes running under VxWorks,
8933 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
8934 stub on the target system.
8936 New CPUs supported include the AMD 29000 and Intel 960.
8938 GDB now reads object files and symbol tables via a ``binary file''
8939 library, which allows a single copy of GDB to debug programs of multiple
8940 object file types such as a.out and coff.
8942 There is now a GDB reference card in "doc/refcard.tex". (Make targets
8943 refcard.dvi and refcard.ps are available to format it).
8946 * Control-Variable user interface simplified
8948 All variables that control the operation of the debugger can be set
8949 by the ``set'' command, and displayed by the ``show'' command.
8951 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
8952 ``Show prompt'' produces the response:
8953 Gdb's prompt is new-gdb=>.
8955 What follows are the NEW set commands. The command ``help set'' will
8956 print a complete list of old and new set commands. ``help set FOO''
8957 will give a longer description of the variable FOO. ``show'' will show
8958 all of the variable descriptions and their current settings.
8960 confirm on/off: Enables warning questions for operations that are
8961 hard to recover from, e.g. rerunning the program while
8962 it is already running. Default is ON.
8964 editing on/off: Enables EMACS style command line editing
8965 of input. Previous lines can be recalled with
8966 control-P, the current line can be edited with control-B,
8967 you can search for commands with control-R, etc.
8970 history filename NAME: NAME is where the gdb command history
8971 will be stored. The default is .gdb_history,
8972 or the value of the environment variable
8975 history size N: The size, in commands, of the command history. The
8976 default is 256, or the value of the environment variable
8979 history save on/off: If this value is set to ON, the history file will
8980 be saved after exiting gdb. If set to OFF, the
8981 file will not be saved. The default is OFF.
8983 history expansion on/off: If this value is set to ON, then csh-like
8984 history expansion will be performed on
8985 command line input. The default is OFF.
8987 radix N: Sets the default radix for input and output. It can be set
8988 to 8, 10, or 16. Note that the argument to "radix" is interpreted
8989 in the current radix, so "set radix 10" is always a no-op.
8991 height N: This integer value is the number of lines on a page. Default
8992 is 24, the current `stty rows'' setting, or the ``li#''
8993 setting from the termcap entry matching the environment
8996 width N: This integer value is the number of characters on a line.
8997 Default is 80, the current `stty cols'' setting, or the ``co#''
8998 setting from the termcap entry matching the environment
9001 Note: ``set screensize'' is obsolete. Use ``set height'' and
9002 ``set width'' instead.
9004 print address on/off: Print memory addresses in various command displays,
9005 such as stack traces and structure values. Gdb looks
9006 more ``symbolic'' if you turn this off; it looks more
9007 ``machine level'' with it on. Default is ON.
9009 print array on/off: Prettyprint arrays. New convenient format! Default
9012 print demangle on/off: Print C++ symbols in "source" form if on,
9015 print asm-demangle on/off: Same, for assembler level printouts
9018 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
9021 * Support for Epoch Environment.
9023 The epoch environment is a version of Emacs v18 with windowing. One
9024 new command, ``inspect'', is identical to ``print'', except that if you
9025 are running in the epoch environment, the value is printed in its own
9029 * Support for Shared Libraries
9031 GDB can now debug programs and core files that use SunOS shared libraries.
9032 Symbols from a shared library cannot be referenced
9033 before the shared library has been linked with the program (this
9034 happens after you type ``run'' and before the function main() is entered).
9035 At any time after this linking (including when examining core files
9036 from dynamically linked programs), gdb reads the symbols from each
9037 shared library when you type the ``sharedlibrary'' command.
9038 It can be abbreviated ``share''.
9040 sharedlibrary REGEXP: Load shared object library symbols for files
9041 matching a unix regular expression. No argument
9042 indicates to load symbols for all shared libraries.
9044 info sharedlibrary: Status of loaded shared libraries.
9049 A watchpoint stops execution of a program whenever the value of an
9050 expression changes. Checking for this slows down execution
9051 tremendously whenever you are in the scope of the expression, but is
9052 quite useful for catching tough ``bit-spreader'' or pointer misuse
9053 problems. Some machines such as the 386 have hardware for doing this
9054 more quickly, and future versions of gdb will use this hardware.
9056 watch EXP: Set a watchpoint (breakpoint) for an expression.
9058 info watchpoints: Information about your watchpoints.
9060 delete N: Deletes watchpoint number N (same as breakpoints).
9061 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
9062 enable N: Re-enables watchpoint number N (same as breakpoints).
9065 * C++ multiple inheritance
9067 When used with a GCC version 2 compiler, GDB supports multiple inheritance
9070 * C++ exception handling
9072 Gdb now supports limited C++ exception handling. Besides the existing
9073 ability to breakpoint on an exception handler, gdb can breakpoint on
9074 the raising of an exception (before the stack is peeled back to the
9077 catch FOO: If there is a FOO exception handler in the dynamic scope,
9078 set a breakpoint to catch exceptions which may be raised there.
9079 Multiple exceptions (``catch foo bar baz'') may be caught.
9081 info catch: Lists all exceptions which may be caught in the
9082 current stack frame.
9085 * Minor command changes
9087 The command ``call func (arg, arg, ...)'' now acts like the print
9088 command, except it does not print or save a value if the function's result
9089 is void. This is similar to dbx usage.
9091 The ``up'' and ``down'' commands now always print the frame they end up
9092 at; ``up-silently'' and `down-silently'' can be used in scripts to change
9093 frames without printing.
9095 * New directory command
9097 'dir' now adds directories to the FRONT of the source search path.
9098 The path starts off empty. Source files that contain debug information
9099 about the directory in which they were compiled can be found even
9100 with an empty path; Sun CC and GCC include this information. If GDB can't
9101 find your source file in the current directory, type "dir .".
9103 * Configuring GDB for compilation
9105 For normal use, type ``./configure host''. See README or gdb.texinfo
9108 GDB now handles cross debugging. If you are remotely debugging between
9109 two different machines, type ``./configure host -target=targ''.
9110 Host is the machine where GDB will run; targ is the machine
9111 where the program that you are debugging will run.