1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.5
6 * New command line options:
8 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
9 other initialization files, unlike -nx which disables all of them.
11 * The 'ptype' and 'whatis' commands now accept an argument to control
16 ** Vectors can be created with gdb.Type.vector.
18 ** Python's atexit.register now works in GDB.
20 ** Types can be pretty-printed via a Python API.
22 * New Python-based convenience functions:
24 ** $_memeq(buf1, buf2, length)
25 ** $_streq(str1, str2)
27 ** $_regex(str, regex)
29 * The 'cd' command now defaults to using '~' (the home directory) if not
32 * The command 'forward-search' can now be abbreviated as 'fo'.
34 * New configure options
36 --enable-libmcheck/--disable-libmcheck
37 By default, development versions are built with -lmcheck on hosts
38 that support it, in order to help track memory corruption issues.
39 Release versions, on the other hand, are built without -lmcheck
40 by default. The --enable-libmcheck/--disable-libmcheck configure
41 options allow the user to override that default.
43 * New commands (for set/show, see "New options" below)
46 List the BFDs known to GDB.
48 python-interactive [command]
50 Start a Python interactive prompt, or evaluate the optional command
51 and print the result of expressions.
54 "py" is a new alias for "python".
56 enable type-printer [name]...
57 disable type-printer [name]...
58 Enable or disable type printers.
62 ** For the Renesas Super-H architecture, the "regs" command has been removed
63 (has been deprecated in GDB 7.5), and "info all-registers" should be used
68 set print type methods (on|off)
69 show print type methods
70 Control whether method declarations are displayed by "ptype".
71 The default is to show them.
73 set print type typedefs (on|off)
74 show print type typedefs
75 Control whether typedef definitions are displayed by "ptype".
76 The default is to show them.
80 ** Command parameter changes are now notified using new async record
82 ** Trace frame changes caused by command "tfind" are now notified using
83 new async record "=traceframe-changed".
84 ** The creation and deletion of trace state variables are now notified
85 using new async records "=tsv-created" and "=tsv-deleted".
86 ** The start and stop of process record are now notified using new
87 async record "=record-started" and "=record-stopped".
88 ** Memory changes are now notified using new async record
90 ** The data-disassemble command response will include a "fullname" field
91 containing the absolute file name when GDB can determine it and source
93 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
94 command, to allow pattern filling of memory areas.
96 *** Changes in GDB 7.5
98 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
99 for more x32 ABI info.
101 * GDB now supports access to MIPS DSP registers on Linux targets.
103 * GDB now supports debugging microMIPS binaries.
105 * The "info os" command on GNU/Linux can now display information on
106 several new classes of objects managed by the operating system:
107 "info os procgroups" lists process groups
108 "info os files" lists file descriptors
109 "info os sockets" lists internet-domain sockets
110 "info os shm" lists shared-memory regions
111 "info os semaphores" lists semaphores
112 "info os msg" lists message queues
113 "info os modules" lists loaded kernel modules
115 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
116 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
117 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
118 options and inspect the probe arguments using the new $_probe_arg family
119 of convenience variables. You can obtain more information about SystemTap
120 in <http://sourceware.org/systemtap/>.
122 * GDB now supports reversible debugging on ARM, it allows you to
123 debug basic ARM and THUMB instructions, and provides
124 record/replay support.
126 * The option "symbol-reloading" has been deleted as it is no longer used.
130 ** GDB commands implemented in Python can now be put in command class
133 ** The "maint set python print-stack on|off" is now deleted.
135 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
136 apply "flag enum"-style pretty-printing to any enum.
138 ** gdb.lookup_symbol can now work when there is no current frame.
140 ** gdb.Symbol now has a 'line' attribute, holding the line number in
141 the source at which the symbol was defined.
143 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
144 method 'value'. The former indicates whether the symbol needs a
145 frame in order to compute its value, and the latter computes the
148 ** A new method 'referenced_value' on gdb.Value objects which can
149 dereference pointer as well as C++ reference values.
151 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
152 which return the global and static blocks (as gdb.Block objects),
153 of the underlying symbol table, respectively.
155 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
156 object associated with a PC value.
158 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
159 of the address range occupied by code for the current source line.
161 * Go language support.
162 GDB now supports debugging programs written in the Go programming
165 * GDBserver now supports stdio connections.
166 E.g. (gdb) target remote | ssh myhost gdbserver - hello
168 * The binary "gdbtui" can no longer be built or installed.
169 Use "gdb -tui" instead.
171 * GDB will now print "flag" enums specially. A flag enum is one where
172 all the enumerator values have no bits in common when pairwise
173 "and"ed. When printing a value whose type is a flag enum, GDB will
174 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
175 (gdb) print (enum E) 3
178 * The filename part of a linespec will now match trailing components
179 of a source file name. For example, "break gcc/expr.c:1000" will
180 now set a breakpoint in build/gcc/expr.c, but not
183 * The "info proc" and "generate-core-file" commands will now also
184 work on remote targets connected to GDBserver on Linux.
186 * The command "info catch" has been removed. It has been disabled
189 * The "catch exception" and "catch assert" commands now accept
190 a condition at the end of the command, much like the "break"
191 command does. For instance:
193 (gdb) catch exception Constraint_Error if Barrier = True
195 Previously, it was possible to add a condition to such catchpoints,
196 but it had to be done as a second step, after the catchpoint had been
197 created, using the "condition" command.
199 * The "info static-tracepoint-marker" command will now also work on
200 native Linux targets with in-process agent.
202 * GDB can now set breakpoints on inlined functions.
204 * The .gdb_index section has been updated to include symbols for
205 inlined functions. GDB will ignore older .gdb_index sections by
206 default, which could cause symbol files to be loaded more slowly
207 until their .gdb_index sections can be recreated. The new command
208 "set use-deprecated-index-sections on" will cause GDB to use any older
209 .gdb_index sections it finds. This will restore performance, but the
210 ability to set breakpoints on inlined functions will be lost in symbol
211 files with older .gdb_index sections.
213 The .gdb_index section has also been updated to record more information
214 about each symbol. This speeds up the "info variables", "info functions"
215 and "info types" commands when used with programs having the .gdb_index
216 section, as well as speeding up debugging with shared libraries using
217 the .gdb_index section.
219 * Ada support for GDB/MI Variable Objects has been added.
221 * GDB can now support 'breakpoint always-inserted mode' in 'record'
226 ** New command -info-os is the MI equivalent of "info os".
228 ** Output logs ("set logging" and related) now include MI output.
232 ** "set use-deprecated-index-sections on|off"
233 "show use-deprecated-index-sections on|off"
234 Controls the use of deprecated .gdb_index sections.
236 ** "catch load" and "catch unload" can be used to stop when a shared
237 library is loaded or unloaded, respectively.
239 ** "enable count" can be used to auto-disable a breakpoint after
242 ** "info vtbl" can be used to show the virtual method tables for
243 C++ and Java objects.
245 ** "explore" and its sub commands "explore value" and "explore type"
246 can be used to reccursively explore values and types of
247 expressions. These commands are available only if GDB is
248 configured with '--with-python'.
250 ** "info auto-load" shows status of all kinds of auto-loaded files,
251 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
252 sequences of commands files, "info auto-load python-scripts"
253 shows status of auto-loading Python script files,
254 "info auto-load local-gdbinit" shows status of loading init file
255 (.gdbinit) from current directory and "info auto-load libthread-db" shows
256 status of inferior specific thread debugging shared library loading.
258 ** "info auto-load-scripts", "set auto-load-scripts on|off"
259 and "show auto-load-scripts" commands have been deprecated, use their
260 "info auto-load python-scripts", "set auto-load python-scripts on|off"
261 and "show auto-load python-scripts" counterparts instead.
263 ** "dprintf location,format,args..." creates a dynamic printf, which
264 is basically a breakpoint that does a printf and immediately
265 resumes your program's execution, so it is like a printf that you
266 can insert dynamically at runtime instead of at compiletime.
268 ** "set print symbol"
270 Controls whether GDB attempts to display the symbol, if any,
271 corresponding to addresses it prints. This defaults to "on", but
272 you can set it to "off" to restore GDB's previous behavior.
274 * Deprecated commands
276 ** For the Renesas Super-H architecture, the "regs" command has been
277 deprecated, and "info all-registers" should be used instead.
281 Renesas RL78 rl78-*-elf
282 HP OpenVMS ia64 ia64-hp-openvms*
284 * GDBserver supports evaluation of breakpoint conditions. When
285 support is advertised by GDBserver, GDB may be told to send the
286 breakpoint conditions in bytecode form to GDBserver. GDBserver
287 will only report the breakpoint trigger to GDB when its condition
293 show mips compression
294 Select the compressed ISA encoding used in functions that have no symbol
295 information available. The encoding can be set to either of:
298 and is updated automatically from ELF file flags if available.
300 set breakpoint condition-evaluation
301 show breakpoint condition-evaluation
302 Control whether breakpoint conditions are evaluated by GDB ("host") or by
303 GDBserver ("target"). Default option "auto" chooses the most efficient
305 This option can improve debugger efficiency depending on the speed of the
309 Disable auto-loading globally.
312 Show auto-loading setting of all kinds of auto-loaded files.
314 set auto-load gdb-scripts on|off
315 show auto-load gdb-scripts
316 Control auto-loading of GDB canned sequences of commands files.
318 set auto-load python-scripts on|off
319 show auto-load python-scripts
320 Control auto-loading of Python script files.
322 set auto-load local-gdbinit on|off
323 show auto-load local-gdbinit
324 Control loading of init file (.gdbinit) from current directory.
326 set auto-load libthread-db on|off
327 show auto-load libthread-db
328 Control auto-loading of inferior specific thread debugging shared library.
330 set auto-load scripts-directory <dir1>[:<dir2>...]
331 show auto-load scripts-directory
332 Set a list of directories from which to load auto-loaded scripts.
333 Automatically loaded Python scripts and GDB scripts are located in one
334 of the directories listed by this option.
335 The delimiter (':' above) may differ according to the host platform.
337 set auto-load safe-path <dir1>[:<dir2>...]
338 show auto-load safe-path
339 Set a list of directories from which it is safe to auto-load files.
340 The delimiter (':' above) may differ according to the host platform.
342 set debug auto-load on|off
344 Control display of debugging info for auto-loading the files above.
346 set dprintf-style gdb|call|agent
348 Control the way in which a dynamic printf is performed; "gdb"
349 requests a GDB printf command, while "call" causes dprintf to call a
350 function in the inferior. "agent" requests that the target agent
351 (such as GDBserver) do the printing.
353 set dprintf-function <expr>
354 show dprintf-function
355 set dprintf-channel <expr>
357 Set the function and optional first argument to the call when using
358 the "call" style of dynamic printf.
360 set disconnected-dprintf on|off
361 show disconnected-dprintf
362 Control whether agent-style dynamic printfs continue to be in effect
363 after GDB disconnects.
365 * New configure options
368 Configure default value for the 'set auto-load scripts-directory'
369 setting above. It defaults to '$debugdir:$datadir/auto-load',
370 $debugdir representing global debugging info directories (available
371 via 'show debug-file-directory') and $datadir representing GDB's data
372 directory (available via 'show data-directory').
374 --with-auto-load-safe-path
375 Configure default value for the 'set auto-load safe-path' setting
376 above. It defaults to the --with-auto-load-dir setting.
378 --without-auto-load-safe-path
379 Set 'set auto-load safe-path' to '/', effectively disabling this
384 z0/z1 conditional breakpoints extension
386 The z0/z1 breakpoint insertion packets have been extended to carry
387 a list of conditional expressions over to the remote stub depending on the
388 condition evaluation mode. The use of this extension can be controlled
389 via the "set remote conditional-breakpoints-packet" command.
393 Specify the signals which the remote stub may pass to the debugged
394 program without GDB involvement.
396 * New command line options
398 --init-command=FILE, -ix Like --command, -x but execute it
399 before loading inferior.
400 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
401 execute it before loading inferior.
403 *** Changes in GDB 7.4
405 * GDB now handles ambiguous linespecs more consistently; the existing
406 FILE:LINE support has been expanded to other types of linespecs. A
407 breakpoint will now be set on all matching locations in all
408 inferiors, and locations will be added or removed according to
411 * GDB now allows you to skip uninteresting functions and files when
412 stepping with the "skip function" and "skip file" commands.
414 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
415 and "show remote hardware-watchpoint-length-limit". These allows to
416 set or show the maximum length limit (in bytes) of a remote
417 target hardware watchpoint.
419 This allows e.g. to use "unlimited" hardware watchpoints with the
420 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
421 watchpoints are slower than real hardware watchpoints but are
422 significantly faster than gdb software watchpoints.
426 ** The register_pretty_printer function in module gdb.printing now takes
427 an optional `replace' argument. If True, the new printer replaces any
430 ** The "maint set python print-stack on|off" command has been
431 deprecated and will be deleted in GDB 7.5.
432 A new command: "set python print-stack none|full|message" has
433 replaced it. Additionally, the default for "print-stack" is
434 now "message", which just prints the error message without
437 ** A prompt substitution hook (prompt_hook) is now available to the
440 ** A new Python module, gdb.prompt has been added to the GDB Python
441 modules library. This module provides functionality for
442 escape sequences in prompts (used by set/show
443 extended-prompt). These escape sequences are replaced by their
446 ** Python commands and convenience-functions located in
447 'data-directory'/python/gdb/command and
448 'data-directory'/python/gdb/function are now automatically loaded
451 ** Blocks now provide four new attributes. global_block and
452 static_block will return the global and static blocks
453 respectively. is_static and is_global are boolean attributes
454 that indicate if the block is one of those two types.
456 ** Symbols now provide the "type" attribute, the type of the symbol.
458 ** The "gdb.breakpoint" function has been deprecated in favor of
461 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
462 of a function. This class is based on the "finish" command
463 available in the CLI.
465 ** Type objects for struct and union types now allow access to
466 the fields using standard Python dictionary (mapping) methods.
467 For example, "some_type['myfield']" now works, as does
470 ** A new event "gdb.new_objfile" has been added, triggered by loading a
473 ** A new function, "deep_items" has been added to the gdb.types
474 module in the GDB Python modules library. This function returns
475 an iterator over the fields of a struct or union type. Unlike
476 the standard Python "iteritems" method, it will recursively traverse
477 any anonymous fields.
481 ** "*stopped" events can report several new "reason"s, such as
484 ** Breakpoint changes are now notified using new async records, like
485 "=breakpoint-modified".
487 ** New command -ada-task-info.
489 * libthread-db-search-path now supports two special values: $sdir and $pdir.
490 $sdir specifies the default system locations of shared libraries.
491 $pdir specifies the directory where the libpthread used by the application
494 GDB no longer looks in $sdir and $pdir after it has searched the directories
495 mentioned in libthread-db-search-path. If you want to search those
496 directories, they must be specified in libthread-db-search-path.
497 The default value of libthread-db-search-path on GNU/Linux and Solaris
498 systems is now "$sdir:$pdir".
500 $pdir is not supported by gdbserver, it is currently ignored.
501 $sdir is supported by gdbserver.
503 * New configure option --with-iconv-bin.
504 When using the internationalization support like the one in the GNU C
505 library, GDB will invoke the "iconv" program to get a list of supported
506 character sets. If this program lives in a non-standard location, one can
507 use this option to specify where to find it.
509 * When natively debugging programs on PowerPC BookE processors running
510 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
511 watchpoints, which specify a mask in addition to an address to watch.
512 The mask specifies that some bits of an address (the bits which are
513 reset in the mask) should be ignored when matching the address accessed
514 by the inferior against the watchpoint address. See the "PowerPC Embedded"
515 section in the user manual for more details.
517 * The new option --once causes GDBserver to stop listening for connections once
518 the first connection is made. The listening port used by GDBserver will
519 become available after that.
521 * New commands "info macros" and "alias" have been added.
523 * New function parameters suffix @entry specifies value of function parameter
524 at the time the function got called. Entry values are available only since
530 "!" is now an alias of the "shell" command.
531 Note that no space is needed between "!" and SHELL COMMAND.
535 watch EXPRESSION mask MASK_VALUE
536 The watch command now supports the mask argument which allows creation
537 of masked watchpoints, if the current architecture supports this feature.
539 info auto-load-scripts [REGEXP]
540 This command was formerly named "maintenance print section-scripts".
541 It is now generally useful and is no longer a maintenance-only command.
543 info macro [-all] [--] MACRO
544 The info macro command has new options `-all' and `--'. The first for
545 printing all definitions of a macro. The second for explicitly specifying
546 the end of arguments and the beginning of the macro name in case the macro
547 name starts with a hyphen.
549 collect[/s] EXPRESSIONS
550 The tracepoint collect command now takes an optional modifier "/s"
551 that directs it to dereference pointer-to-character types and
552 collect the bytes of memory up to a zero byte. The behavior is
553 similar to what you see when you use the regular print command on a
554 string. An optional integer following the "/s" sets a bound on the
555 number of bytes that will be collected.
558 The trace start command now interprets any supplied arguments as a
559 note to be recorded with the trace run, with an effect similar to
560 setting the variable trace-notes.
563 The trace stop command now interprets any arguments as a note to be
564 mentioned along with the tstatus report that the trace was stopped
565 with a command. The effect is similar to setting the variable
568 * Tracepoints can now be enabled and disabled at any time after a trace
569 experiment has been started using the standard "enable" and "disable"
570 commands. It is now possible to start a trace experiment with no enabled
571 tracepoints; GDB will display a warning, but will allow the experiment to
572 begin, assuming that tracepoints will be enabled as needed while the trace
575 * Fast tracepoints on 32-bit x86-architectures can now be placed at
576 locations with 4-byte instructions, when they were previously
577 limited to locations with instructions of 5 bytes or longer.
581 set debug dwarf2-read
582 show debug dwarf2-read
583 Turns on or off display of debugging messages related to reading
584 DWARF debug info. The default is off.
586 set debug symtab-create
587 show debug symtab-create
588 Turns on or off display of debugging messages related to symbol table
589 creation. The default is off.
593 Set the GDB prompt, and allow escape sequences to be inserted to
594 display miscellaneous information (see 'help set extended-prompt'
595 for the list of sequences). This prompt (and any information
596 accessed through the escape sequences) is updated every time the
599 set print entry-values (both|compact|default|if-needed|no|only|preferred)
600 show print entry-values
601 Set printing of frame argument values at function entry. In some cases
602 GDB can determine the value of function argument which was passed by the
603 function caller, even if the value was modified inside the called function.
605 set debug entry-values
606 show debug entry-values
607 Control display of debugging info for determining frame argument values at
608 function entry and virtual tail call frames.
610 set basenames-may-differ
611 show basenames-may-differ
612 Set whether a source file may have multiple base names.
613 (A "base name" is the name of a file with the directory part removed.
614 Example: The base name of "/home/user/hello.c" is "hello.c".)
615 If set, GDB will canonicalize file names (e.g., expand symlinks)
616 before comparing them. Canonicalization is an expensive operation,
617 but it allows the same file be known by more than one base name.
618 If not set (the default), all source files are assumed to have just
619 one base name, and gdb will do file name comparisons more efficiently.
625 Set a user name and notes for the current and any future trace runs.
626 This is useful for long-running and/or disconnected traces, to
627 inform others (or yourself) as to who is running the trace, supply
628 contact information, or otherwise explain what is going on.
631 show trace-stop-notes
632 Set a note attached to the trace run, that is displayed when the
633 trace has been stopped by a tstop command. This is useful for
634 instance as an explanation, if you are stopping a trace run that was
635 started by someone else.
641 Dynamically enable a tracepoint in a started trace experiment.
645 Dynamically disable a tracepoint in a started trace experiment.
649 Set the user and notes of the trace run.
653 Query the current status of a tracepoint.
657 Query the minimum length of instruction at which a fast tracepoint may
660 * Dcache size (number of lines) and line-size are now runtime-configurable
661 via "set dcache line" and "set dcache line-size" commands.
665 Texas Instruments TMS320C6x tic6x-*-*
669 Renesas RL78 rl78-*-elf
671 *** Changes in GDB 7.3.1
673 * The build failure for NetBSD and OpenBSD targets have now been fixed.
675 *** Changes in GDB 7.3
677 * GDB has a new command: "thread find [REGEXP]".
678 It finds the thread id whose name, target id, or thread extra info
679 matches the given regular expression.
681 * The "catch syscall" command now works on mips*-linux* targets.
683 * The -data-disassemble MI command now supports modes 2 and 3 for
684 dumping the instruction opcodes.
686 * New command line options
688 -data-directory DIR Specify DIR as the "data-directory".
689 This is mostly for testing purposes.
691 * The "maint set python auto-load on|off" command has been renamed to
692 "set auto-load-scripts on|off".
694 * GDB has a new command: "set directories".
695 It is like the "dir" command except that it replaces the
696 source path list instead of augmenting it.
698 * GDB now understands thread names.
700 On GNU/Linux, "info threads" will display the thread name as set by
701 prctl or pthread_setname_np.
703 There is also a new command, "thread name", which can be used to
704 assign a name internally for GDB to display.
707 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
708 has been integrated into GDB.
712 ** The function gdb.Write now accepts an optional keyword 'stream'.
713 This keyword, when provided, will direct the output to either
714 stdout, stderr, or GDB's logging output.
716 ** Parameters can now be be sub-classed in Python, and in particular
717 you may implement the get_set_doc and get_show_doc functions.
718 This improves how Parameter set/show documentation is processed
719 and allows for more dynamic content.
721 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
722 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
723 have an is_valid method.
725 ** Breakpoints can now be sub-classed in Python, and in particular
726 you may implement a 'stop' function that is executed each time
727 the inferior reaches that breakpoint.
729 ** New function gdb.lookup_global_symbol looks up a global symbol.
731 ** GDB values in Python are now callable if the value represents a
732 function. For example, if 'some_value' represents a function that
733 takes two integer parameters and returns a value, you can call
734 that function like so:
736 result = some_value (10,20)
738 ** Module gdb.types has been added.
739 It contains a collection of utilities for working with gdb.Types objects:
740 get_basic_type, has_field, make_enum_dict.
742 ** Module gdb.printing has been added.
743 It contains utilities for writing and registering pretty-printers.
744 New classes: PrettyPrinter, SubPrettyPrinter,
745 RegexpCollectionPrettyPrinter.
746 New function: register_pretty_printer.
748 ** New commands "info pretty-printers", "enable pretty-printer" and
749 "disable pretty-printer" have been added.
751 ** gdb.parameter("directories") is now available.
753 ** New function gdb.newest_frame returns the newest frame in the
756 ** The gdb.InferiorThread class has a new "name" attribute. This
757 holds the thread's name.
759 ** Python Support for Inferior events.
760 Python scripts can add observers to be notified of events
761 occurring in the process being debugged.
762 The following events are currently supported:
763 - gdb.events.cont Continue event.
764 - gdb.events.exited Inferior exited event.
765 - gdb.events.stop Signal received, and Breakpoint hit events.
769 ** GDB now puts template parameters in scope when debugging in an
770 instantiation. For example, if you have:
772 template<int X> int func (void) { return X; }
774 then if you step into func<5>, "print X" will show "5". This
775 feature requires proper debuginfo support from the compiler; it
776 was added to GCC 4.5.
778 ** The motion commands "next", "finish", "until", and "advance" now
779 work better when exceptions are thrown. In particular, GDB will
780 no longer lose control of the inferior; instead, the GDB will
781 stop the inferior at the point at which the exception is caught.
782 This functionality requires a change in the exception handling
783 code that was introduced in GCC 4.5.
785 * GDB now follows GCC's rules on accessing volatile objects when
786 reading or writing target state during expression evaluation.
787 One notable difference to prior behavior is that "print x = 0"
788 no longer generates a read of x; the value of the assignment is
789 now always taken directly from the value being assigned.
791 * GDB now has some support for using labels in the program's source in
792 linespecs. For instance, you can use "advance label" to continue
793 execution to a label.
795 * GDB now has support for reading and writing a new .gdb_index
796 section. This section holds a fast index of DWARF debugging
797 information and can be used to greatly speed up GDB startup and
798 operation. See the documentation for `save gdb-index' for details.
800 * The "watch" command now accepts an optional "-location" argument.
801 When used, this causes GDB to watch the memory referred to by the
802 expression. Such a watchpoint is never deleted due to it going out
805 * GDB now supports thread debugging of core dumps on GNU/Linux.
807 GDB now activates thread debugging using the libthread_db library
808 when debugging GNU/Linux core dumps, similarly to when debugging
809 live processes. As a result, when debugging a core dump file, GDB
810 is now able to display pthread_t ids of threads. For example, "info
811 threads" shows the same output as when debugging the process when it
812 was live. In earlier releases, you'd see something like this:
815 * 1 LWP 6780 main () at main.c:10
817 While now you see this:
820 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
822 It is also now possible to inspect TLS variables when debugging core
825 When debugging a core dump generated on a machine other than the one
826 used to run GDB, you may need to point GDB at the correct
827 libthread_db library with the "set libthread-db-search-path"
828 command. See the user manual for more details on this command.
830 * When natively debugging programs on PowerPC BookE processors running
831 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
832 which stop execution of the inferior whenever it executes an instruction
833 at any address within the specified range. See the "PowerPC Embedded"
834 section in the user manual for more details.
836 * New features in the GDB remote stub, GDBserver
838 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
839 and i686 LynxOS (version 5.x).
841 ** GDBserver is now supported on Blackfin Linux.
843 * New native configurations
845 ia64 HP-UX ia64-*-hpux*
849 Analog Devices, Inc. Blackfin Processor bfin-*
851 * Ada task switching is now supported on sparc-elf targets when
852 debugging a program using the Ravenscar Profile. For more information,
853 see the "Tasking Support when using the Ravenscar Profile" section
854 in the GDB user manual.
856 * Guile support was removed.
858 * New features in the GNU simulator
860 ** The --map-info flag lists all known core mappings.
862 ** CFI flashes may be simulated via the "cfi" device.
864 *** Changes in GDB 7.2
866 * Shared library support for remote targets by default
868 When GDB is configured for a generic, non-OS specific target, like
869 for example, --target=arm-eabi or one of the many *-*-elf targets,
870 GDB now queries remote stubs for loaded shared libraries using the
871 `qXfer:libraries:read' packet. Previously, shared library support
872 was always disabled for such configurations.
876 ** Argument Dependent Lookup (ADL)
878 In C++ ADL lookup directs function search to the namespaces of its
879 arguments even if the namespace has not been imported.
889 Here the compiler will search for `foo' in the namespace of 'b'
890 and find A::foo. GDB now supports this. This construct is commonly
891 used in the Standard Template Library for operators.
893 ** Improved User Defined Operator Support
895 In addition to member operators, GDB now supports lookup of operators
896 defined in a namespace and imported with a `using' directive, operators
897 defined in the global scope, operators imported implicitly from an
898 anonymous namespace, and the ADL operators mentioned in the previous
900 GDB now also supports proper overload resolution for all the previously
901 mentioned flavors of operators.
903 ** static const class members
905 Printing of static const class members that are initialized in the
906 class definition has been fixed.
908 * Windows Thread Information Block access.
910 On Windows targets, GDB now supports displaying the Windows Thread
911 Information Block (TIB) structure. This structure is visible either
912 by using the new command `info w32 thread-information-block' or, by
913 dereferencing the new convenience variable named `$_tlb', a
914 thread-specific pointer to the TIB. This feature is also supported
915 when remote debugging using GDBserver.
919 Static tracepoints are calls in the user program into a tracing
920 library. One such library is a port of the LTTng kernel tracer to
921 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
922 When debugging with GDBserver, GDB now supports combining the GDB
923 tracepoint machinery with such libraries. For example: the user can
924 use GDB to probe a static tracepoint marker (a call from the user
925 program into the tracing library) with the new "strace" command (see
926 "New commands" below). This creates a "static tracepoint" in the
927 breakpoint list, that can be manipulated with the same feature set
928 as fast and regular tracepoints. E.g., collect registers, local and
929 global variables, collect trace state variables, and define
930 tracepoint conditions. In addition, the user can collect extra
931 static tracepoint marker specific data, by collecting the new
932 $_sdata internal variable. When analyzing the trace buffer, you can
933 inspect $_sdata like any other variable available to GDB. For more
934 information, see the "Tracepoints" chapter in GDB user manual. New
935 remote packets have been defined to support static tracepoints, see
936 the "New remote packets" section below.
938 * Better reconstruction of tracepoints after disconnected tracing
940 GDB will attempt to download the original source form of tracepoint
941 definitions when starting a trace run, and then will upload these
942 upon reconnection to the target, resulting in a more accurate
943 reconstruction of the tracepoints that are in use on the target.
947 You can now exercise direct control over the ways that GDB can
948 affect your program. For instance, you can disallow the setting of
949 breakpoints, so that the program can run continuously (assuming
950 non-stop mode). In addition, the "observer" variable is available
951 to switch all of the different controls; in observer mode, GDB
952 cannot affect the target's behavior at all, which is useful for
953 tasks like diagnosing live systems in the field.
955 * The new convenience variable $_thread holds the number of the
962 Return the address of the Windows Thread Information Block of a given thread.
966 In response to several of the tracepoint packets, the target may now
967 also respond with a number of intermediate `qRelocInsn' request
968 packets before the final result packet, to have GDB handle
969 relocating an instruction to execute at a different address. This
970 is particularly useful for stubs that support fast tracepoints. GDB
971 reports support for this feature in the qSupported packet.
975 List static tracepoint markers in the target program.
979 List static tracepoint markers at a given address in the target
982 qXfer:statictrace:read
984 Read the static trace data collected (by a `collect $_sdata'
985 tracepoint action). The remote stub reports support for this packet
986 to gdb's qSupported query.
990 Send the current settings of GDB's permission flags.
994 Send part of the source (textual) form of a tracepoint definition,
995 which includes location, conditional, and action list.
997 * The source command now accepts a -s option to force searching for the
998 script in the source search path even if the script name specifies
1001 * New features in the GDB remote stub, GDBserver
1003 - GDBserver now support tracepoints (including fast tracepoints, and
1004 static tracepoints). The feature is currently supported by the
1005 i386-linux and amd64-linux builds. See the "Tracepoints support
1006 in gdbserver" section in the manual for more information.
1008 GDBserver JIT compiles the tracepoint's conditional agent
1009 expression bytecode into native code whenever possible for low
1010 overhead dynamic tracepoints conditionals. For such tracepoints,
1011 an expression that examines program state is evaluated when the
1012 tracepoint is reached, in order to determine whether to capture
1013 trace data. If the condition is simple and false, processing the
1014 tracepoint finishes very quickly and no data is gathered.
1016 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1017 for static tracepoints support.
1019 - GDBserver now supports x86_64 Windows 64-bit debugging.
1021 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1022 it understands register description.
1024 * The --batch flag now disables pagination and queries.
1026 * X86 general purpose registers
1028 GDB now supports reading/writing byte, word and double-word x86
1029 general purpose registers directly. This means you can use, say,
1030 $ah or $ax to refer, respectively, to the byte register AH and
1031 16-bit word register AX that are actually portions of the 32-bit
1032 register EAX or 64-bit register RAX.
1034 * The `commands' command now accepts a range of breakpoints to modify.
1035 A plain `commands' following a command that creates multiple
1036 breakpoints affects all the breakpoints set by that command. This
1037 applies to breakpoints set by `rbreak', and also applies when a
1038 single `break' command creates multiple breakpoints (e.g.,
1039 breakpoints on overloaded c++ functions).
1041 * The `rbreak' command now accepts a filename specification as part of
1042 its argument, limiting the functions selected by the regex to those
1043 in the specified file.
1045 * Support for remote debugging Windows and SymbianOS shared libraries
1046 from Unix hosts has been improved. Non Windows GDB builds now can
1047 understand target reported file names that follow MS-DOS based file
1048 system semantics, such as file names that include drive letters and
1049 use the backslash character as directory separator. This makes it
1050 possible to transparently use the "set sysroot" and "set
1051 solib-search-path" on Unix hosts to point as host copies of the
1052 target's shared libraries. See the new command "set
1053 target-file-system-kind" described below, and the "Commands to
1054 specify files" section in the user manual for more information.
1058 eval template, expressions...
1059 Convert the values of one or more expressions under the control
1060 of the string template to a command line, and call it.
1062 set target-file-system-kind unix|dos-based|auto
1063 show target-file-system-kind
1064 Set or show the assumed file system kind for target reported file
1067 save breakpoints <filename>
1068 Save all current breakpoint definitions to a file suitable for use
1069 in a later debugging session. To read the saved breakpoint
1070 definitions, use the `source' command.
1072 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1075 info static-tracepoint-markers
1076 Display information about static tracepoint markers in the target.
1078 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1079 Define a static tracepoint by probing a marker at the given
1080 function, line, address, or marker ID.
1084 Enable and disable observer mode.
1086 set may-write-registers on|off
1087 set may-write-memory on|off
1088 set may-insert-breakpoints on|off
1089 set may-insert-tracepoints on|off
1090 set may-insert-fast-tracepoints on|off
1091 set may-interrupt on|off
1092 Set individual permissions for GDB effects on the target. Note that
1093 some of these settings can have undesirable or surprising
1094 consequences, particularly when changed in the middle of a session.
1095 For instance, disabling the writing of memory can prevent
1096 breakpoints from being inserted, cause single-stepping to fail, or
1097 even crash your program, if you disable after breakpoints have been
1098 inserted. However, GDB should not crash.
1100 set record memory-query on|off
1101 show record memory-query
1102 Control whether to stop the inferior if memory changes caused
1103 by an instruction cannot be recorded.
1108 The disassemble command now supports "start,+length" form of two arguments.
1112 ** GDB now provides a new directory location, called the python directory,
1113 where Python scripts written for GDB can be installed. The location
1114 of that directory is <data-directory>/python, where <data-directory>
1115 is the GDB data directory. For more details, see section `Scripting
1116 GDB using Python' in the manual.
1118 ** The GDB Python API now has access to breakpoints, symbols, symbol
1119 tables, program spaces, inferiors, threads and frame's code blocks.
1120 Additionally, GDB Parameters can now be created from the API, and
1121 manipulated via set/show in the CLI.
1123 ** New functions gdb.target_charset, gdb.target_wide_charset,
1124 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1126 ** New exception gdb.GdbError.
1128 ** Pretty-printers are now also looked up in the current program space.
1130 ** Pretty-printers can now be individually enabled and disabled.
1132 ** GDB now looks for names of Python scripts to auto-load in a
1133 special section named `.debug_gdb_scripts', in addition to looking
1134 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1136 * Tracepoint actions were unified with breakpoint commands. In particular,
1137 there are no longer differences in "info break" output for breakpoints and
1138 tracepoints and the "commands" command can be used for both tracepoints and
1139 regular breakpoints.
1143 ARM Symbian arm*-*-symbianelf*
1145 * D language support.
1146 GDB now supports debugging programs written in the D programming
1149 * GDB now supports the extended ptrace interface for PowerPC which is
1150 available since Linux kernel version 2.6.34. This automatically enables
1151 any hardware breakpoints and additional hardware watchpoints available in
1152 the processor. The old ptrace interface exposes just one hardware
1153 watchpoint and no hardware breakpoints.
1155 * GDB is now able to use the Data Value Compare (DVC) register available on
1156 embedded PowerPC processors to implement in hardware simple watchpoint
1157 conditions of the form:
1159 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1161 This works in native GDB running on Linux kernels with the extended ptrace
1162 interface mentioned above.
1164 *** Changes in GDB 7.1
1168 ** Namespace Support
1170 GDB now supports importing of namespaces in C++. This enables the
1171 user to inspect variables from imported namespaces. Support for
1172 namepace aliasing has also been added. So, if a namespace is
1173 aliased in the current scope (e.g. namepace C=A; ) the user can
1174 print variables using the alias (e.g. (gdb) print C::x).
1178 All known bugs relating to the printing of virtual base class were
1179 fixed. It is now possible to call overloaded static methods using a
1184 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1185 and reinterpret_cast<> are now handled by the C++ expression parser.
1189 Xilinx MicroBlaze microblaze-*-*
1194 Xilinx MicroBlaze microblaze
1197 * Multi-program debugging.
1199 GDB now has support for multi-program (a.k.a. multi-executable or
1200 multi-exec) debugging. This allows for debugging multiple inferiors
1201 simultaneously each running a different program under the same GDB
1202 session. See "Debugging Multiple Inferiors and Programs" in the
1203 manual for more information. This implied some user visible changes
1204 in the multi-inferior support. For example, "info inferiors" now
1205 lists inferiors that are not running yet or that have exited
1206 already. See also "New commands" and "New options" below.
1208 * New tracing features
1210 GDB's tracepoint facility now includes several new features:
1212 ** Trace state variables
1214 GDB tracepoints now include support for trace state variables, which
1215 are variables managed by the target agent during a tracing
1216 experiment. They are useful for tracepoints that trigger each
1217 other, so for instance one tracepoint can count hits in a variable,
1218 and then a second tracepoint has a condition that is true when the
1219 count reaches a particular value. Trace state variables share the
1220 $-syntax of GDB convenience variables, and can appear in both
1221 tracepoint actions and condition expressions. Use the "tvariable"
1222 command to create, and "info tvariables" to view; see "Trace State
1223 Variables" in the manual for more detail.
1227 GDB now includes an option for defining fast tracepoints, which
1228 targets may implement more efficiently, such as by installing a jump
1229 into the target agent rather than a trap instruction. The resulting
1230 speedup can be by two orders of magnitude or more, although the
1231 tradeoff is that some program locations on some target architectures
1232 might not allow fast tracepoint installation, for instance if the
1233 instruction to be replaced is shorter than the jump. To request a
1234 fast tracepoint, use the "ftrace" command, with syntax identical to
1235 the regular trace command.
1237 ** Disconnected tracing
1239 It is now possible to detach GDB from the target while it is running
1240 a trace experiment, then reconnect later to see how the experiment
1241 is going. In addition, a new variable disconnected-tracing lets you
1242 tell the target agent whether to continue running a trace if the
1243 connection is lost unexpectedly.
1247 GDB now has the ability to save the trace buffer into a file, and
1248 then use that file as a target, similarly to you can do with
1249 corefiles. You can select trace frames, print data that was
1250 collected in them, and use tstatus to display the state of the
1251 tracing run at the moment that it was saved. To create a trace
1252 file, use "tsave <filename>", and to use it, do "target tfile
1255 ** Circular trace buffer
1257 You can ask the target agent to handle the trace buffer as a
1258 circular buffer, discarding the oldest trace frames to make room for
1259 newer ones, by setting circular-trace-buffer to on. This feature may
1260 not be available for all target agents.
1265 The disassemble command, when invoked with two arguments, now requires
1266 the arguments to be comma-separated.
1269 The info variables command now displays variable definitions. Files
1270 which only declare a variable are not shown.
1273 The source command is now capable of sourcing Python scripts.
1274 This feature is dependent on the debugger being build with Python
1277 Related to this enhancement is also the introduction of a new command
1278 "set script-extension" (see below).
1280 * New commands (for set/show, see "New options" below)
1282 record save [<FILENAME>]
1283 Save a file (in core file format) containing the process record
1284 execution log for replay debugging at a later time.
1286 record restore <FILENAME>
1287 Restore the process record execution log that was saved at an
1288 earlier time, for replay debugging.
1290 add-inferior [-copies <N>] [-exec <FILENAME>]
1293 clone-inferior [-copies <N>] [ID]
1294 Make a new inferior ready to execute the same program another
1295 inferior has loaded.
1300 maint info program-spaces
1301 List the program spaces loaded into GDB.
1303 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1304 show remote interrupt-sequence
1305 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1306 as the sequence to the remote target in order to interrupt the execution.
1307 Ctrl-C is a default. Some system prefers BREAK which is high level of
1308 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1309 Magic SysRq g. It is BREAK signal and character 'g'.
1311 set remote interrupt-on-connect [on | off]
1312 show remote interrupt-on-connect
1313 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1314 remote target when gdb connects to it. This is needed when you debug
1317 set remotebreak [on | off]
1319 Deprecated. Use "set/show remote interrupt-sequence" instead.
1321 tvariable $NAME [ = EXP ]
1322 Create or modify a trace state variable.
1325 List trace state variables and their values.
1327 delete tvariable $NAME ...
1328 Delete one or more trace state variables.
1331 Evaluate the given expressions without collecting anything into the
1332 trace buffer. (Valid in tracepoint actions only.)
1334 ftrace FN / FILE:LINE / *ADDR
1335 Define a fast tracepoint at the given function, line, or address.
1337 * New expression syntax
1339 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1340 GDB now parses 0b101010 identically with 42.
1344 set follow-exec-mode new|same
1345 show follow-exec-mode
1346 Control whether GDB reuses the same inferior across an exec call or
1347 creates a new one. This is useful to be able to restart the old
1348 executable after the inferior having done an exec call.
1350 set default-collect EXPR, ...
1351 show default-collect
1352 Define a list of expressions to be collected at each tracepoint.
1353 This is a useful way to ensure essential items are not overlooked,
1354 such as registers or a critical global variable.
1356 set disconnected-tracing
1357 show disconnected-tracing
1358 If set to 1, the target is instructed to continue tracing if it
1359 loses its connection to GDB. If 0, the target is to stop tracing
1362 set circular-trace-buffer
1363 show circular-trace-buffer
1364 If set to on, the target is instructed to use a circular trace buffer
1365 and discard the oldest trace frames instead of stopping the trace due
1366 to a full trace buffer. If set to off, the trace stops when the buffer
1367 fills up. Some targets may not support this.
1369 set script-extension off|soft|strict
1370 show script-extension
1371 If set to "off", the debugger does not perform any script language
1372 recognition, and all sourced files are assumed to be GDB scripts.
1373 If set to "soft" (the default), files are sourced according to
1374 filename extension, falling back to GDB scripts if the first
1376 If set to "strict", files are sourced according to filename extension.
1378 set ada trust-PAD-over-XVS on|off
1379 show ada trust-PAD-over-XVS
1380 If off, activate a workaround against a bug in the debugging information
1381 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1382 the GCC sources for more information about the GNAT encoding and
1383 PAD types in particular). It is always safe to set this option to
1384 off, but this introduces a slight performance penalty. The default
1387 * Python API Improvements
1389 ** GDB provides the new class gdb.LazyString. This is useful in
1390 some pretty-printing cases. The new method gdb.Value.lazy_string
1391 provides a simple way to create objects of this type.
1393 ** The fields returned by gdb.Type.fields now have an
1394 `is_base_class' attribute.
1396 ** The new method gdb.Type.range returns the range of an array type.
1398 ** The new method gdb.parse_and_eval can be used to parse and
1399 evaluate an expression.
1401 * New remote packets
1404 Define a trace state variable.
1407 Get the current value of a trace state variable.
1410 Set desired tracing behavior upon disconnection.
1413 Set the trace buffer to be linear or circular.
1416 Get data about the tracepoints currently in use.
1420 Process record now works correctly with hardware watchpoints.
1422 Multiple bug fixes have been made to the mips-irix port, making it
1423 much more reliable. In particular:
1424 - Debugging threaded applications is now possible again. Previously,
1425 GDB would hang while starting the program, or while waiting for
1426 the program to stop at a breakpoint.
1427 - Attaching to a running process no longer hangs.
1428 - An error occurring while loading a core file has been fixed.
1429 - Changing the value of the PC register now works again. This fixes
1430 problems observed when using the "jump" command, or when calling
1431 a function from GDB, or even when assigning a new value to $pc.
1432 - With the "finish" and "return" commands, the return value for functions
1433 returning a small array is now correctly printed.
1434 - It is now possible to break on shared library code which gets executed
1435 during a shared library init phase (code executed while executing
1436 their .init section). Previously, the breakpoint would have no effect.
1437 - GDB is now able to backtrace through the signal handler for
1438 non-threaded programs.
1440 PIE (Position Independent Executable) programs debugging is now supported.
1441 This includes debugging execution of PIC (Position Independent Code) shared
1442 libraries although for that, it should be possible to run such libraries as an
1445 *** Changes in GDB 7.0
1447 * GDB now has an interface for JIT compilation. Applications that
1448 dynamically generate code can create symbol files in memory and register
1449 them with GDB. For users, the feature should work transparently, and
1450 for JIT developers, the interface is documented in the GDB manual in the
1451 "JIT Compilation Interface" chapter.
1453 * Tracepoints may now be conditional. The syntax is as for
1454 breakpoints; either an "if" clause appended to the "trace" command,
1455 or the "condition" command is available. GDB sends the condition to
1456 the target for evaluation using the same bytecode format as is used
1457 for tracepoint actions.
1459 * The disassemble command now supports: an optional /r modifier, print the
1460 raw instructions in hex as well as in symbolic form, and an optional /m
1461 modifier to print mixed source+assembly.
1463 * Process record and replay
1465 In a architecture environment that supports ``process record and
1466 replay'', ``process record and replay'' target can record a log of
1467 the process execution, and replay it with both forward and reverse
1470 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1471 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1472 set execution-direction {forward|reverse}, for targets that support
1475 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1476 feature is available with a native GDB running on kernel version
1479 * GDB now has support for multi-byte and wide character sets on the
1480 target. Strings whose character type is wchar_t, char16_t, or
1481 char32_t are now correctly printed. GDB supports wide- and unicode-
1482 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1483 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1484 `printf'. This feature requires iconv to work properly; if your
1485 system does not have a working iconv, GDB can use GNU libiconv. See
1486 the installation instructions for more information.
1488 * GDB now supports automatic retrieval of shared library files from
1489 remote targets. To use this feature, specify a system root that begins
1490 with the `remote:' prefix, either via the `set sysroot' command or via
1491 the `--with-sysroot' configure-time option.
1493 * "info sharedlibrary" now takes an optional regex of libraries to show,
1494 and it now reports if a shared library has no debugging information.
1496 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1497 now complete on file names.
1499 * When completing in expressions, gdb will attempt to limit
1500 completions to allowable structure or union fields, where appropriate.
1501 For instance, consider:
1503 # struct example { int f1; double f2; };
1504 # struct example variable;
1507 If the user types TAB at the end of this command line, the available
1508 completions will be "f1" and "f2".
1510 * Inlined functions are now supported. They show up in backtraces, and
1511 the "step", "next", and "finish" commands handle them automatically.
1513 * GDB now supports the token-splicing (##) and stringification (#)
1514 operators when expanding macros. It also supports variable-arity
1517 * GDB now supports inspecting extra signal information, exported by
1518 the new $_siginfo convenience variable. The feature is currently
1519 implemented on linux ARM, i386 and amd64.
1521 * GDB can now display the VFP floating point registers and NEON vector
1522 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1523 can provide these registers (requires Linux 2.6.30 or later). Remote
1524 and simulator targets may also provide them.
1526 * New remote packets
1529 Search memory for a sequence of bytes.
1532 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1533 operation over reliable transport links. Use of this packet is
1534 controlled by the `set remote noack-packet' command.
1537 Kill the process with the specified process ID. Use this in preference
1538 to `k' when multiprocess protocol extensions are supported.
1541 Obtains additional operating system information
1545 Read or write additional signal information.
1547 * Removed remote protocol undocumented extension
1549 An undocumented extension to the remote protocol's `S' stop reply
1550 packet that permited the stub to pass a process id was removed.
1551 Remote servers should use the `T' stop reply packet instead.
1553 * GDB now supports multiple function calling conventions according to the
1554 DWARF-2 DW_AT_calling_convention function attribute.
1556 * The SH target utilizes the aforementioned change to distinguish between gcc
1557 and Renesas calling convention. It also adds the new CLI commands
1558 `set/show sh calling-convention'.
1560 * GDB can now read compressed debug sections, as produced by GNU gold
1561 with the --compress-debug-sections=zlib flag.
1563 * 64-bit core files are now supported on AIX.
1565 * Thread switching is now supported on Tru64.
1567 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1568 which will be allocated using malloc later in program execution.
1570 * The qXfer:libraries:read remote procotol packet now allows passing a
1571 list of section offsets.
1573 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1574 conditions handling signals delivered during attach or thread creation
1575 have also been fixed.
1577 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1578 From the user's standpoint, all unqualified instances of True and False
1579 are treated as the standard definitions, regardless of context.
1581 * GDB now parses C++ symbol and type names more flexibly. For
1584 template<typename T> class C { };
1587 GDB will now correctly handle all of:
1589 ptype C<char const *>
1590 ptype C<char const*>
1591 ptype C<const char *>
1592 ptype C<const char*>
1594 * New features in the GDB remote stub, gdbserver
1596 - The "--wrapper" command-line argument tells gdbserver to use a
1597 wrapper program to launch programs for debugging.
1599 - On PowerPC and S/390 targets, it is now possible to use a single
1600 gdbserver executable to debug both 32-bit and 64-bit programs.
1601 (This requires gdbserver itself to be built as a 64-bit executable.)
1603 - gdbserver uses the new noack protocol mode for TCP connections to
1604 reduce communications latency, if also supported and enabled in GDB.
1606 - Support for the sparc64-linux-gnu target is now included in
1609 - The amd64-linux build of gdbserver now supports debugging both
1610 32-bit and 64-bit programs.
1612 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1613 now support hardware watchpoints, and will use them automatically
1618 GDB now has support for scripting using Python. Whether this is
1619 available is determined at configure time.
1621 New GDB commands can now be written in Python.
1623 * Ada tasking support
1625 Ada tasks can now be inspected in GDB. The following commands have
1629 Print the list of Ada tasks.
1631 Print detailed information about task number N.
1633 Print the task number of the current task.
1635 Switch the context of debugging to task number N.
1637 * Support for user-defined prefixed commands. The "define" command can
1638 add new commands to existing prefixes, e.g. "target".
1640 * Multi-inferior, multi-process debugging.
1642 GDB now has generalized support for multi-inferior debugging. See
1643 "Debugging Multiple Inferiors" in the manual for more information.
1644 Although availability still depends on target support, the command
1645 set is more uniform now. The GNU/Linux specific multi-forks support
1646 has been migrated to this new framework. This implied some user
1647 visible changes; see "New commands" and also "Removed commands"
1650 * Target descriptions can now describe the target OS ABI. See the
1651 "Target Description Format" section in the user manual for more
1654 * Target descriptions can now describe "compatible" architectures
1655 to indicate that the target can execute applications for a different
1656 architecture in addition to those for the main target architecture.
1657 See the "Target Description Format" section in the user manual for
1660 * Multi-architecture debugging.
1662 GDB now includes general supports for debugging applications on
1663 hybrid systems that use more than one single processor architecture
1664 at the same time. Each such hybrid architecture still requires
1665 specific support to be added. The only hybrid architecture supported
1666 in this version of GDB is the Cell Broadband Engine.
1668 * GDB now supports integrated debugging of Cell/B.E. applications that
1669 use both the PPU and SPU architectures. To enable support for hybrid
1670 Cell/B.E. debugging, you need to configure GDB to support both the
1671 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1672 --enable-targets configure option.
1674 * Non-stop mode debugging.
1676 For some targets, GDB now supports an optional mode of operation in
1677 which you can examine stopped threads while other threads continue
1678 to execute freely. This is referred to as non-stop mode, with the
1679 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1680 section in the user manual for more information.
1682 To be able to support remote non-stop debugging, a remote stub needs
1683 to implement the non-stop mode remote protocol extensions, as
1684 described in the "Remote Non-Stop" section of the user manual. The
1685 GDB remote stub, gdbserver, has been adjusted to support these
1686 extensions on linux targets.
1688 * New commands (for set/show, see "New options" below)
1690 catch syscall [NAME(S) | NUMBER(S)]
1691 Catch system calls. Arguments, which should be names of system
1692 calls or their numbers, mean catch only those syscalls. Without
1693 arguments, every syscall will be caught. When the inferior issues
1694 any of the specified syscalls, GDB will stop and announce the system
1695 call, both when it is called and when its call returns. This
1696 feature is currently available with a native GDB running on the
1697 Linux Kernel, under the following architectures: x86, x86_64,
1698 PowerPC and PowerPC64.
1700 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1702 Search memory for a sequence of bytes.
1704 maint set python print-stack
1705 maint show python print-stack
1706 Show a stack trace when an error is encountered in a Python script.
1709 Invoke CODE by passing it to the Python interpreter.
1714 These allow macros to be defined, undefined, and listed
1718 Show operating system information about processes.
1721 List the inferiors currently under GDB's control.
1724 Switch focus to inferior number NUM.
1727 Detach from inferior number NUM.
1730 Kill inferior number NUM.
1734 set spu stop-on-load
1735 show spu stop-on-load
1736 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1738 set spu auto-flush-cache
1739 show spu auto-flush-cache
1740 Control whether to automatically flush the software-managed cache
1741 during Cell/B.E. debugging.
1743 set sh calling-convention
1744 show sh calling-convention
1745 Control the calling convention used when calling SH target functions.
1748 show debug timestamp
1749 Control display of timestamps with GDB debugging output.
1751 set disassemble-next-line
1752 show disassemble-next-line
1753 Control display of disassembled source lines or instructions when
1756 set remote noack-packet
1757 show remote noack-packet
1758 Set/show the use of remote protocol QStartNoAckMode packet. See above
1759 under "New remote packets."
1761 set remote query-attached-packet
1762 show remote query-attached-packet
1763 Control use of remote protocol `qAttached' (query-attached) packet.
1765 set remote read-siginfo-object
1766 show remote read-siginfo-object
1767 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1770 set remote write-siginfo-object
1771 show remote write-siginfo-object
1772 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1775 set remote reverse-continue
1776 show remote reverse-continue
1777 Control use of remote protocol 'bc' (reverse-continue) packet.
1779 set remote reverse-step
1780 show remote reverse-step
1781 Control use of remote protocol 'bs' (reverse-step) packet.
1783 set displaced-stepping
1784 show displaced-stepping
1785 Control displaced stepping mode. Displaced stepping is a way to
1786 single-step over breakpoints without removing them from the debuggee.
1787 Also known as "out-of-line single-stepping".
1790 show debug displaced
1791 Control display of debugging info for displaced stepping.
1793 maint set internal-error
1794 maint show internal-error
1795 Control what GDB does when an internal error is detected.
1797 maint set internal-warning
1798 maint show internal-warning
1799 Control what GDB does when an internal warning is detected.
1804 Use a wrapper program to launch programs for debugging.
1806 set multiple-symbols (all|ask|cancel)
1807 show multiple-symbols
1808 The value of this variable can be changed to adjust the debugger behavior
1809 when an expression or a breakpoint location contains an ambiguous symbol
1810 name (an overloaded function name, for instance).
1812 set breakpoint always-inserted
1813 show breakpoint always-inserted
1814 Keep breakpoints always inserted in the target, as opposed to inserting
1815 them when resuming the target, and removing them when the target stops.
1816 This option can improve debugger performance on slow remote targets.
1818 set arm fallback-mode (arm|thumb|auto)
1819 show arm fallback-mode
1820 set arm force-mode (arm|thumb|auto)
1822 These commands control how ARM GDB determines whether instructions
1823 are ARM or Thumb. The default for both settings is auto, which uses
1824 the current CPSR value for instructions without symbols; previous
1825 versions of GDB behaved as if "set arm fallback-mode arm".
1827 set disable-randomization
1828 show disable-randomization
1829 Standalone programs run with the virtual address space randomization enabled
1830 by default on some platforms. This option keeps the addresses stable across
1831 multiple debugging sessions.
1835 Control whether other threads are stopped or not when some thread hits
1840 Requests that asynchronous execution is enabled in the target, if available.
1841 In this case, it's possible to resume target in the background, and interact
1842 with GDB while the target is running. "show target-async" displays the
1843 current state of asynchronous execution of the target.
1845 set target-wide-charset
1846 show target-wide-charset
1847 The target-wide-charset is the name of the character set that GDB
1848 uses when printing characters whose type is wchar_t.
1850 set tcp auto-retry (on|off)
1852 set tcp connect-timeout
1853 show tcp connect-timeout
1854 These commands allow GDB to retry failed TCP connections to a remote stub
1855 with a specified timeout period; this is useful if the stub is launched
1856 in parallel with GDB but may not be ready to accept connections immediately.
1858 set libthread-db-search-path
1859 show libthread-db-search-path
1860 Control list of directories which GDB will search for appropriate
1863 set schedule-multiple (on|off)
1864 show schedule-multiple
1865 Allow GDB to resume all threads of all processes or only threads of
1866 the current process.
1870 Use more aggressive caching for accesses to the stack. This improves
1871 performance of remote debugging (particularly backtraces) without
1872 affecting correctness.
1874 set interactive-mode (on|off|auto)
1875 show interactive-mode
1876 Control whether GDB runs in interactive mode (on) or not (off).
1877 When in interactive mode, GDB waits for the user to answer all
1878 queries. Otherwise, GDB does not wait and assumes the default
1879 answer. When set to auto (the default), GDB determines which
1880 mode to use based on the stdin settings.
1885 For program forks, this is replaced by the new more generic `info
1886 inferiors' command. To list checkpoints, you can still use the
1887 `info checkpoints' command, which was an alias for the `info forks'
1891 Replaced by the new `inferior' command. To switch between
1892 checkpoints, you can still use the `restart' command, which was an
1893 alias for the `fork' command.
1896 This is removed, since some targets don't have a notion of
1897 processes. To switch between processes, you can still use the
1898 `inferior' command using GDB's own inferior number.
1901 For program forks, this is replaced by the new more generic `kill
1902 inferior' command. To delete a checkpoint, you can still use the
1903 `delete checkpoint' command, which was an alias for the `delete
1907 For program forks, this is replaced by the new more generic `detach
1908 inferior' command. To detach a checkpoint, you can still use the
1909 `detach checkpoint' command, which was an alias for the `detach
1912 * New native configurations
1914 x86/x86_64 Darwin i[34567]86-*-darwin*
1916 x86_64 MinGW x86_64-*-mingw*
1920 Lattice Mico32 lm32-*
1921 x86 DICOS i[34567]86-*-dicos*
1922 x86_64 DICOS x86_64-*-dicos*
1925 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1926 (mingw32ce) debugging.
1932 These commands were actually not implemented on any target.
1934 *** Changes in GDB 6.8
1936 * New native configurations
1938 NetBSD/hppa hppa*-*netbsd*
1939 Xtensa GNU/Linux xtensa*-*-linux*
1943 NetBSD/hppa hppa*-*-netbsd*
1944 Xtensa GNU/Lunux xtensa*-*-linux*
1946 * Change in command line behavior -- corefiles vs. process ids.
1948 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1949 attaching to process NUMBER fails, GDB no longer attempts to open a
1950 core file named NUMBER. Attaching to a program using the -c option
1951 is no longer supported. Instead, use the '-p' or '--pid' options.
1953 * GDB can now be built as a native debugger for debugging Windows x86
1954 (mingw32) Portable Executable (PE) programs.
1956 * Pending breakpoints no longer change their number when their address
1959 * GDB now supports breakpoints with multiple locations,
1960 including breakpoints on C++ constructors, inside C++ templates,
1961 and in inlined functions.
1963 * GDB's ability to debug optimized code has been improved. GDB more
1964 accurately identifies function bodies and lexical blocks that occupy
1965 more than one contiguous range of addresses.
1967 * Target descriptions can now describe registers for PowerPC.
1969 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1970 registers on PowerPC targets.
1972 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1973 targets even when the libthread_db library is not available.
1975 * The GDB remote stub, gdbserver, now supports the new file transfer
1976 commands (remote put, remote get, and remote delete).
1978 * The GDB remote stub, gdbserver, now supports run and attach in
1979 extended-remote mode.
1981 * hppa*64*-*-hpux11* target broken
1982 The debugger is unable to start a program and fails with the following
1983 error: "Error trying to get information about dynamic linker".
1984 The gdb-6.7 release is also affected.
1986 * GDB now supports the --enable-targets= configure option to allow
1987 building a single GDB executable that supports multiple remote
1988 target architectures.
1990 * GDB now supports debugging C and C++ programs which use the
1991 Decimal Floating Point extension. In addition, the PowerPC target
1992 now has a set of pseudo-registers to inspect decimal float values
1993 stored in two consecutive float registers.
1995 * The -break-insert MI command can optionally create pending
1998 * Improved support for debugging Ada
1999 Many improvements to the Ada language support have been made. These
2001 - Better support for Ada2005 interface types
2002 - Improved handling of arrays and slices in general
2003 - Better support for Taft-amendment types
2004 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2006 - Improved command completion in Ada
2009 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2014 set print frame-arguments (all|scalars|none)
2015 show print frame-arguments
2016 The value of this variable can be changed to control which argument
2017 values should be printed by the debugger when displaying a frame.
2022 Transfer files to and from a remote target, and delete remote files.
2029 Transfer files to and from a remote target, and delete remote files.
2031 * New remote packets
2038 Open, close, read, write, and delete files on the remote system.
2041 Attach to an existing process on the remote system, in extended-remote
2045 Run a new process on the remote system, in extended-remote mode.
2047 *** Changes in GDB 6.7
2049 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2050 bfd, libiberty and opcodes, as revealed by static analysis donated by
2051 Coverity, Inc. (http://scan.coverity.com).
2053 * When looking up multiply-defined global symbols, GDB will now prefer the
2054 symbol definition in the current shared library if it was built using the
2055 -Bsymbolic linker option.
2057 * When the Text User Interface (TUI) is not configured, GDB will now
2058 recognize the -tui command-line option and print a message that the TUI
2061 * The GDB remote stub, gdbserver, now has lower overhead for high
2062 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2064 * GDB for MIPS targets now autodetects whether a remote target provides
2065 32-bit or 64-bit register values.
2067 * Support for C++ member pointers has been improved.
2069 * GDB now understands XML target descriptions, which specify the
2070 target's overall architecture. GDB can read a description from
2071 a local file or over the remote serial protocol.
2073 * Vectors of single-byte data use a new integer type which is not
2074 automatically displayed as character or string data.
2076 * The /s format now works with the print command. It displays
2077 arrays of single-byte integers and pointers to single-byte integers
2080 * Target descriptions can now describe target-specific registers,
2081 for architectures which have implemented the support (currently
2082 only ARM, M68K, and MIPS).
2084 * GDB and the GDB remote stub, gdbserver, now support the XScale
2087 * The GDB remote stub, gdbserver, has been updated to support
2088 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2089 has been rewritten to use the standard GDB remote protocol.
2091 * GDB can now step into C++ functions which are called through thunks.
2093 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2095 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2096 layout. It also supports a TextSeg= and DataSeg= response when only
2097 segment base addresses (rather than offsets) are available.
2099 * The /i format now outputs any trailing branch delay slot instructions
2100 immediately following the last instruction within the count specified.
2102 * The GDB remote protocol "T" stop reply packet now supports a
2103 "library" response. Combined with the new "qXfer:libraries:read"
2104 packet, this response allows GDB to debug shared libraries on targets
2105 where the operating system manages the list of loaded libraries (e.g.
2106 Windows and SymbianOS).
2108 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2109 (DLLs) on Windows and Windows CE targets.
2111 * GDB now supports a faster verification that a .debug file matches its binary
2112 according to its build-id signature, if the signature is present.
2118 Enable or disable hardware flow control (RTS/CTS) on the serial port
2119 when debugging using remote targets.
2121 set mem inaccessible-by-default
2122 show mem inaccessible-by-default
2123 If the target supplies a memory map, for instance via the remote
2124 protocol's "qXfer:memory-map:read" packet, setting this variable
2125 prevents GDB from accessing memory outside the memory map. This
2126 is useful for targets with memory mapped registers or which react
2127 badly to accesses of unmapped address space.
2129 set breakpoint auto-hw
2130 show breakpoint auto-hw
2131 If the target supplies a memory map, for instance via the remote
2132 protocol's "qXfer:memory-map:read" packet, setting this variable
2133 lets GDB use hardware breakpoints automatically for memory regions
2134 where it can not use software breakpoints. This covers both the
2135 "break" command and internal breakpoints used for other commands
2136 including "next" and "finish".
2139 catch exception unhandled
2140 Stop the program execution when Ada exceptions are raised.
2143 Stop the program execution when an Ada assertion failed.
2147 Set an alternate system root for target files. This is a more
2148 general version of "set solib-absolute-prefix", which is now
2149 an alias to "set sysroot".
2152 Provide extended SPU facility status information. This set of
2153 commands is available only when debugging the Cell/B.E. SPU
2156 * New native configurations
2158 OpenBSD/sh sh*-*openbsd*
2161 unset tdesc filename
2163 Use the specified local file as an XML target description, and do
2164 not query the target for its built-in description.
2168 OpenBSD/sh sh*-*-openbsd*
2169 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2170 Toshiba Media Processor mep-elf
2172 * New remote packets
2175 Ignore the specified signals; pass them directly to the debugged program
2176 without stopping other threads or reporting them to GDB.
2178 qXfer:features:read:
2179 Read an XML target description from the target, which describes its
2184 Read or write contents of an spufs file on the target system. These
2185 packets are available only on the Cell/B.E. SPU architecture.
2187 qXfer:libraries:read:
2188 Report the loaded shared libraries. Combined with new "T" packet
2189 response, this packet allows GDB to debug shared libraries on
2190 targets where the operating system manages the list of loaded
2191 libraries (e.g. Windows and SymbianOS).
2195 Support for these obsolete configurations has been removed.
2203 i[34567]86-*-lynxos*
2204 i[34567]86-*-netware*
2205 i[34567]86-*-sco3.2v5*
2206 i[34567]86-*-sco3.2v4*
2208 i[34567]86-*-sysv4.2*
2211 i[34567]86-*-unixware2*
2212 i[34567]86-*-unixware*
2221 * Other removed features
2228 Various m68k-only ROM monitors.
2235 Various Renesas ROM monitors and debugging interfaces for SH and
2240 Support for a Macraigor serial interface to on-chip debugging.
2241 GDB does not directly support the newer parallel or USB
2246 A debug information format. The predecessor to DWARF 2 and
2247 DWARF 3, which are still supported.
2249 Support for the HP aCC compiler on HP-UX/PA-RISC
2251 SOM-encapsulated symbolic debugging information, automatic
2252 invocation of pxdb, and the aCC custom C++ ABI. This does not
2253 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2254 with aCC can still be debugged on an assembly level.
2256 MIPS ".pdr" sections
2258 A MIPS-specific format used to describe stack frame layout
2259 in debugging information.
2263 GDB could work with an older version of Guile to debug
2264 the interpreter and Scheme programs running in it.
2266 set mips stack-arg-size
2267 set mips saved-gpreg-size
2269 Use "set mips abi" to control parameter passing for MIPS.
2271 *** Changes in GDB 6.6
2276 Cell Broadband Engine SPU spu-elf
2278 * GDB can now be configured as a cross-debugger targeting native Windows
2279 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2280 running on a Windows system over TCP/IP to debug Windows programs.
2282 * The GDB remote stub, gdbserver, has been updated to support Windows and
2283 Cygwin debugging. Both single-threaded and multi-threaded programs are
2286 * The "set trust-readonly-sections" command works again. This command was
2287 broken in GDB 6.3, 6.4, and 6.5.
2289 * The "load" command now supports writing to flash memory, if the remote
2290 stub provides the required support.
2292 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2293 longer requires symbolic debug information (e.g. DWARF-2).
2298 unset substitute-path
2299 show substitute-path
2300 Manage a list of substitution rules that GDB uses to rewrite the name
2301 of the directories where the sources are located. This can be useful
2302 for instance when the sources were moved to a different location
2303 between compilation and debugging.
2307 Print each CLI command as it is executed. Each command is prefixed with
2308 a number of `+' symbols representing the nesting depth.
2309 The source command now has a `-v' option to enable the same feature.
2313 The ARM Demon monitor support (RDP protocol, "target rdp").
2315 Kernel Object Display, an embedded debugging feature which only worked with
2316 an obsolete version of Cisco IOS.
2318 The 'set download-write-size' and 'show download-write-size' commands.
2320 * New remote packets
2323 Tell a stub about GDB client features, and request remote target features.
2324 The first feature implemented is PacketSize, which allows the target to
2325 specify the size of packets it can handle - to minimize the number of
2326 packets required and improve performance when connected to a remote
2330 Fetch an OS auxilliary vector from the remote stub. This packet is a
2331 more efficient replacement for qPart:auxv:read.
2333 qXfer:memory-map:read:
2334 Fetch a memory map from the remote stub, including information about
2335 RAM, ROM, and flash memory devices.
2340 Erase and program a flash memory device.
2342 * Removed remote packets
2345 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2346 used it, and only gdbserver implemented it.
2348 *** Changes in GDB 6.5
2352 Renesas M32C/M16C m32c-elf
2354 Morpho Technologies ms1 ms1-elf
2358 init-if-undefined Initialize a convenience variable, but
2359 only if it doesn't already have a value.
2361 The following commands are presently only implemented for native GNU/Linux:
2363 checkpoint Save a snapshot of the program state.
2365 restart <n> Return the program state to a
2366 previously saved state.
2368 info checkpoints List currently saved checkpoints.
2370 delete-checkpoint <n> Delete a previously saved checkpoint.
2372 set|show detach-on-fork Tell gdb whether to detach from a newly
2373 forked process, or to keep debugging it.
2375 info forks List forks of the user program that
2376 are available to be debugged.
2378 fork <n> Switch to debugging one of several
2379 forks of the user program that are
2380 available to be debugged.
2382 delete-fork <n> Delete a fork from the list of forks
2383 that are available to be debugged (and
2384 kill the forked process).
2386 detach-fork <n> Delete a fork from the list of forks
2387 that are available to be debugged (and
2388 allow the process to continue).
2392 Morpho Technologies ms2 ms1-elf
2394 * Improved Windows host support
2396 GDB now builds as a cross debugger hosted on i686-mingw32, including
2397 native console support, and remote communications using either
2398 network sockets or serial ports.
2400 * Improved Modula-2 language support
2402 GDB can now print most types in the Modula-2 syntax. This includes:
2403 basic types, set types, record types, enumerated types, range types,
2404 pointer types and ARRAY types. Procedure var parameters are correctly
2405 printed and hexadecimal addresses and character constants are also
2406 written in the Modula-2 syntax. Best results can be obtained by using
2407 GNU Modula-2 together with the -gdwarf-2 command line option.
2411 The ARM rdi-share module.
2413 The Netware NLM debug server.
2415 *** Changes in GDB 6.4
2417 * New native configurations
2419 OpenBSD/arm arm*-*-openbsd*
2420 OpenBSD/mips64 mips64-*-openbsd*
2424 Morpho Technologies ms1 ms1-elf
2426 * New command line options
2428 --batch-silent As for --batch, but totally silent.
2429 --return-child-result The debugger will exist with the same value
2430 the child (debugged) program exited with.
2431 --eval-command COMMAND, -ex COMMAND
2432 Execute a single GDB CLI command. This may be
2433 specified multiple times and in conjunction
2434 with the --command (-x) option.
2436 * Deprecated commands removed
2438 The following commands, that were deprecated in 2000, have been
2442 set|show arm disassembly-flavor set|show arm disassembler
2443 othernames set arm disassembler
2444 set|show remotedebug set|show debug remote
2445 set|show archdebug set|show debug arch
2446 set|show eventdebug set|show debug event
2449 * New BSD user-level threads support
2451 It is now possible to debug programs using the user-level threads
2452 library on OpenBSD and FreeBSD. Currently supported (target)
2455 FreeBSD/amd64 x86_64-*-freebsd*
2456 FreeBSD/i386 i386-*-freebsd*
2457 OpenBSD/i386 i386-*-openbsd*
2459 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2460 are not yet supported.
2462 * New support for Matsushita MN10300 w/sim added
2463 (Work in progress). mn10300-elf.
2465 * REMOVED configurations and files
2467 VxWorks and the XDR protocol *-*-vxworks
2468 Motorola MCORE mcore-*-*
2469 National Semiconductor NS32000 ns32k-*-*
2471 * New "set print array-indexes" command
2473 After turning this setting "on", GDB prints the index of each element
2474 when displaying arrays. The default is "off" to preserve the previous
2477 * VAX floating point support
2479 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2481 * User-defined command support
2483 In addition to using $arg0..$arg9 for argument passing, it is now possible
2484 to use $argc to determine now many arguments have been passed. See the
2485 section on user-defined commands in the user manual for more information.
2487 *** Changes in GDB 6.3:
2489 * New command line option
2491 GDB now accepts -l followed by a number to set the timeout for remote
2494 * GDB works with GCC -feliminate-dwarf2-dups
2496 GDB now supports a more compact representation of DWARF-2 debug
2497 information using DW_FORM_ref_addr references. These are produced
2498 by GCC with the option -feliminate-dwarf2-dups and also by some
2499 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2500 to use -feliminate-dwarf2-dups.
2502 * Internationalization
2504 When supported by the host system, GDB will be built with
2505 internationalization (libintl). The task of marking up the sources is
2506 continued, we're looking forward to our first translation.
2510 Initial support for debugging programs compiled with the GNAT
2511 implementation of the Ada programming language has been integrated
2512 into GDB. In this release, support is limited to expression evaluation.
2514 * New native configurations
2516 GNU/Linux/m32r m32r-*-linux-gnu
2520 GDB's remote protocol now includes support for the 'p' packet. This
2521 packet is used to fetch individual registers from a remote inferior.
2523 * END-OF-LIFE registers[] compatibility module
2525 GDB's internal register infrastructure has been completely rewritten.
2526 The new infrastructure making possible the implementation of key new
2527 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2530 GDB 6.3 will be the last release to include the the registers[]
2531 compatibility module that allowed out-of-date configurations to
2532 continue to work. This change directly impacts the following
2542 powerpc bdm protocol
2544 Unless there is activity to revive these configurations, they will be
2545 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2547 * OBSOLETE configurations and files
2549 Configurations that have been declared obsolete in this release have
2550 been commented out. Unless there is activity to revive these
2551 configurations, the next release of GDB will have their sources
2552 permanently REMOVED.
2561 *** Changes in GDB 6.2.1:
2563 * MIPS `break main; run' gave an heuristic-fence-post warning
2565 When attempting to run even a simple program, a warning about
2566 heuristic-fence-post being hit would be reported. This problem has
2569 * MIPS IRIX 'long double' crashed GDB
2571 When examining a long double variable, GDB would get a segmentation
2572 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2573 IRIX long double values).
2577 A bug in the VAX stack code was causing problems with the "next"
2578 command. This problem has been fixed.
2580 *** Changes in GDB 6.2:
2582 * Fix for ``many threads''
2584 On GNU/Linux systems that use the NPTL threads library, a program
2585 rapidly creating and deleting threads would confuse GDB leading to the
2588 ptrace: No such process.
2589 thread_db_get_info: cannot get thread info: generic error
2591 This problem has been fixed.
2593 * "-async" and "-noasync" options removed.
2595 Support for the broken "-noasync" option has been removed (it caused
2598 * New ``start'' command.
2600 This command runs the program until the begining of the main procedure.
2602 * New BSD Kernel Data Access Library (libkvm) interface
2604 Using ``target kvm'' it is now possible to debug kernel core dumps and
2605 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2606 platforms. Currently supported (native-only) configurations are:
2608 FreeBSD/amd64 x86_64-*-freebsd*
2609 FreeBSD/i386 i?86-*-freebsd*
2610 NetBSD/i386 i?86-*-netbsd*
2611 NetBSD/m68k m68*-*-netbsd*
2612 NetBSD/sparc sparc-*-netbsd*
2613 OpenBSD/amd64 x86_64-*-openbsd*
2614 OpenBSD/i386 i?86-*-openbsd*
2615 OpenBSD/m68k m68*-openbsd*
2616 OpenBSD/sparc sparc-*-openbsd*
2618 * Signal trampoline code overhauled
2620 Many generic problems with GDB's signal handling code have been fixed.
2621 These include: backtraces through non-contiguous stacks; recognition
2622 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2623 call; backtrace through a signal trampoline; step into and out of
2624 signal handlers; and single-stepping in the signal trampoline.
2626 Please note that kernel bugs are a limiting factor here. These
2627 features have been shown to work on an s390 GNU/Linux system that
2628 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2630 * Cygwin support for DWARF 2 added.
2632 * New native configurations
2634 GNU/Linux/hppa hppa*-*-linux*
2635 OpenBSD/hppa hppa*-*-openbsd*
2636 OpenBSD/m68k m68*-*-openbsd*
2637 OpenBSD/m88k m88*-*-openbsd*
2638 OpenBSD/powerpc powerpc-*-openbsd*
2639 NetBSD/vax vax-*-netbsd*
2640 OpenBSD/vax vax-*-openbsd*
2642 * END-OF-LIFE frame compatibility module
2644 GDB's internal frame infrastructure has been completely rewritten.
2645 The new infrastructure making it possible to support key new features
2646 including DWARF 2 Call Frame Information. To aid in the task of
2647 migrating old configurations to this new infrastructure, a
2648 compatibility module, that allowed old configurations to continue to
2649 work, was also included.
2651 GDB 6.2 will be the last release to include this frame compatibility
2652 module. This change directly impacts the following configurations:
2662 Unless there is activity to revive these configurations, they will be
2663 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2665 * REMOVED configurations and files
2667 Sun 3, running SunOS 3 m68*-*-sunos3*
2668 Sun 3, running SunOS 4 m68*-*-sunos4*
2669 Sun 2, running SunOS 3 m68000-*-sunos3*
2670 Sun 2, running SunOS 4 m68000-*-sunos4*
2671 Motorola 680x0 running LynxOS m68*-*-lynxos*
2672 AT&T 3b1/Unix pc m68*-att-*
2673 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2674 decstation mips-dec-* mips-little-*
2675 riscos mips-*-riscos* mips-*-sysv*
2676 sonymips mips-sony-*
2677 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2679 *** Changes in GDB 6.1.1:
2681 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2683 The TUI (Text-mode User Interface) is now built as part of a default
2684 GDB configuration. It is enabled by either selecting the TUI with the
2685 command line option "-i=tui" or by running the separate "gdbtui"
2686 program. For more information on the TUI, see the manual "Debugging
2689 * Pending breakpoint support (also included in GDB 6.1)
2691 Support has been added to allow you to specify breakpoints in shared
2692 libraries that have not yet been loaded. If a breakpoint location
2693 cannot be found, and the "breakpoint pending" option is set to auto,
2694 GDB queries you if you wish to make the breakpoint pending on a future
2695 shared-library load. If and when GDB resolves the breakpoint symbol,
2696 the pending breakpoint is removed as one or more regular breakpoints
2699 Pending breakpoints are very useful for GCJ Java debugging.
2701 * Fixed ISO-C build problems
2703 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2704 non ISO-C code that stopped them being built using a more strict ISO-C
2705 compiler (e.g., IBM's C compiler).
2707 * Fixed build problem on IRIX 5
2709 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2710 wasn't able to compile compile on an IRIX 5 system.
2712 * Added execute permission to gdb/gdbserver/configure
2714 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2715 permission. This bug would cause configure to fail on a number of
2716 systems (Solaris, IRIX). Ref: server/519.
2718 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2720 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2721 has been updated to use constant array sizes.
2723 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2725 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2726 its generated DWARF Call Frame Info. This encoding was causing GDB to
2727 panic, that panic has been fixed. Ref: gdb/1628.
2729 * Fixed a problem when examining parameters in shared library code.
2731 When examining parameters in optimized shared library code generated
2732 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2733 not available''. GDB now correctly displays the variable's value.
2735 *** Changes in GDB 6.1:
2737 * Removed --with-mmalloc
2739 Support for the mmalloc memory manager has been removed, as it
2740 conflicted with the internal gdb byte cache.
2742 * Changes in AMD64 configurations
2744 The AMD64 target now includes the %cs and %ss registers. As a result
2745 the AMD64 remote protocol has changed; this affects the floating-point
2746 and SSE registers. If you rely on those registers for your debugging,
2747 you should upgrade gdbserver on the remote side.
2749 * Revised SPARC target
2751 The SPARC target has been completely revised, incorporating the
2752 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2753 support for LynxOS and SunOS 4 has been dropped. Calling functions
2754 from within GDB on operating systems with a non-executable stack
2755 (Solaris, OpenBSD) now works.
2759 GDB has a new C++ demangler which does a better job on the mangled
2760 names generated by current versions of g++. It also runs faster, so
2761 with this and other changes gdb should now start faster on large C++
2764 * DWARF 2 Location Expressions
2766 GDB support for location expressions has been extended to support function
2767 arguments and frame bases. Older versions of GDB could crash when they
2770 * C++ nested types and namespaces
2772 GDB's support for nested types and namespaces in C++ has been
2773 improved, especially if you use the DWARF 2 debugging format. (This
2774 is the default for recent versions of GCC on most platforms.)
2775 Specifically, if you have a class "Inner" defined within a class or
2776 namespace "Outer", then GDB realizes that the class's name is
2777 "Outer::Inner", not simply "Inner". This should greatly reduce the
2778 frequency of complaints about not finding RTTI symbols. In addition,
2779 if you are stopped at inside of a function defined within a namespace,
2780 GDB modifies its name lookup accordingly.
2782 * New native configurations
2784 NetBSD/amd64 x86_64-*-netbsd*
2785 OpenBSD/amd64 x86_64-*-openbsd*
2786 OpenBSD/alpha alpha*-*-openbsd*
2787 OpenBSD/sparc sparc-*-openbsd*
2788 OpenBSD/sparc64 sparc64-*-openbsd*
2790 * New debugging protocols
2792 M32R with SDI protocol m32r-*-elf*
2794 * "set prompt-escape-char" command deleted.
2796 The command "set prompt-escape-char" has been deleted. This command,
2797 and its very obscure effet on GDB's prompt, was never documented,
2798 tested, nor mentioned in the NEWS file.
2800 * OBSOLETE configurations and files
2802 Configurations that have been declared obsolete in this release have
2803 been commented out. Unless there is activity to revive these
2804 configurations, the next release of GDB will have their sources
2805 permanently REMOVED.
2807 Sun 3, running SunOS 3 m68*-*-sunos3*
2808 Sun 3, running SunOS 4 m68*-*-sunos4*
2809 Sun 2, running SunOS 3 m68000-*-sunos3*
2810 Sun 2, running SunOS 4 m68000-*-sunos4*
2811 Motorola 680x0 running LynxOS m68*-*-lynxos*
2812 AT&T 3b1/Unix pc m68*-att-*
2813 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2814 decstation mips-dec-* mips-little-*
2815 riscos mips-*-riscos* mips-*-sysv*
2816 sonymips mips-sony-*
2817 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2819 * REMOVED configurations and files
2821 SGI Irix-4.x mips-sgi-irix4 or iris4
2822 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2823 Z8000 simulator z8k-zilog-none or z8ksim
2824 Matsushita MN10200 w/simulator mn10200-*-*
2825 H8/500 simulator h8500-hitachi-hms or h8500hms
2826 HP/PA running BSD hppa*-*-bsd*
2827 HP/PA running OSF/1 hppa*-*-osf*
2828 HP/PA Pro target hppa*-*-pro*
2829 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2830 386BSD i[3456]86-*-bsd*
2831 Sequent family i[3456]86-sequent-sysv4*
2832 i[3456]86-sequent-sysv*
2833 i[3456]86-sequent-bsd*
2834 SPARC running LynxOS sparc-*-lynxos*
2835 SPARC running SunOS 4 sparc-*-sunos4*
2836 Tsqware Sparclet sparclet-*-*
2837 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2839 *** Changes in GDB 6.0:
2843 Support for debugging the Objective-C programming language has been
2844 integrated into GDB.
2846 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2848 DWARF 2's Call Frame Information makes available compiler generated
2849 information that more exactly describes the program's run-time stack.
2850 By using this information, GDB is able to provide more robust stack
2853 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2854 have been updated to use a new backtrace mechanism which includes
2855 DWARF 2 CFI support.
2859 GDB's remote protocol has been extended to include support for hosted
2860 file I/O (where the remote target uses GDB's file system). See GDB's
2861 remote protocol documentation for details.
2863 * All targets using the new architecture framework.
2865 All of GDB's targets have been updated to use the new internal
2866 architecture framework. The way is now open for future GDB releases
2867 to include cross-architecture native debugging support (i386 on amd64,
2870 * GNU/Linux's Thread Local Storage (TLS)
2872 GDB now includes support for for the GNU/Linux implementation of
2873 per-thread variables.
2875 * GNU/Linux's Native POSIX Thread Library (NPTL)
2877 GDB's thread code has been updated to work with either the new
2878 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2880 * Separate debug info.
2882 GDB, in conjunction with BINUTILS, now supports a mechanism for
2883 automatically loading debug information from a separate file. Instead
2884 of shipping full debug and non-debug versions of system libraries,
2885 system integrators can now instead ship just the stripped libraries
2886 and optional debug files.
2888 * DWARF 2 Location Expressions
2890 DWARF 2 Location Expressions allow the compiler to more completely
2891 describe the location of variables (even in optimized code) to the
2894 GDB now includes preliminary support for location expressions (support
2895 for DW_OP_piece is still missing).
2899 A number of long standing bugs that caused GDB to die while starting a
2900 Java application have been fixed. GDB's Java support is now
2901 considered "useable".
2903 * GNU/Linux support for fork, vfork, and exec.
2905 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2906 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2909 * GDB supports logging output to a file
2911 There are two new commands, "set logging" and "show logging", which can be
2912 used to capture GDB's output to a file.
2914 * The meaning of "detach" has changed for gdbserver
2916 The "detach" command will now resume the application, as documented. To
2917 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2920 * d10v, m68hc11 `regs' command deprecated
2922 The `info registers' command has been updated so that it displays the
2923 registers using a format identical to the old `regs' command.
2927 A new command, "maint set profile on/off", has been added. This command can
2928 be used to enable or disable profiling while running GDB, to profile a
2929 session or a set of commands. In addition there is a new configure switch,
2930 "--enable-profiling", which will cause GDB to be compiled with profiling
2931 data, for more informative profiling results.
2933 * Default MI syntax changed to "mi2".
2935 The default MI (machine interface) syntax, enabled by the command line
2936 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2937 "mi1", can be enabled by specifying the option "-i=mi1".
2939 Support for the original "mi0" syntax (included in GDB 5.0) has been
2942 Fix for gdb/192: removed extraneous space when displaying frame level.
2943 Fix for gdb/672: update changelist is now output in mi list format.
2944 Fix for gdb/702: a -var-assign that updates the value now shows up
2945 in a subsequent -var-update.
2947 * New native configurations.
2949 FreeBSD/amd64 x86_64-*-freebsd*
2951 * Multi-arched targets.
2953 HP/PA HPUX11 hppa*-*-hpux*
2954 Renesas M32R/D w/simulator m32r-*-elf*
2956 * OBSOLETE configurations and files
2958 Configurations that have been declared obsolete in this release have
2959 been commented out. Unless there is activity to revive these
2960 configurations, the next release of GDB will have their sources
2961 permanently REMOVED.
2963 Z8000 simulator z8k-zilog-none or z8ksim
2964 Matsushita MN10200 w/simulator mn10200-*-*
2965 H8/500 simulator h8500-hitachi-hms or h8500hms
2966 HP/PA running BSD hppa*-*-bsd*
2967 HP/PA running OSF/1 hppa*-*-osf*
2968 HP/PA Pro target hppa*-*-pro*
2969 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2970 Sequent family i[3456]86-sequent-sysv4*
2971 i[3456]86-sequent-sysv*
2972 i[3456]86-sequent-bsd*
2973 Tsqware Sparclet sparclet-*-*
2974 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2976 * REMOVED configurations and files
2979 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2980 IBM AIX PS/2 i[3456]86-*-aix
2981 i386 running Mach 3.0 i[3456]86-*-mach3*
2982 i386 running Mach i[3456]86-*-mach*
2983 i386 running OSF/1 i[3456]86-*osf1mk*
2984 HP/Apollo 68k Family m68*-apollo*-sysv*,
2986 m68*-hp-bsd*, m68*-hp-hpux*
2987 Argonaut Risc Chip (ARC) arc-*-*
2988 Mitsubishi D30V d30v-*-*
2989 Fujitsu FR30 fr30-*-elf*
2990 OS/9000 i[34]86-*-os9k
2991 I960 with MON960 i960-*-coff
2993 * MIPS $fp behavior changed
2995 The convenience variable $fp, for the MIPS, now consistently returns
2996 the address of the current frame's base. Previously, depending on the
2997 context, $fp could refer to either $sp or the current frame's base
2998 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2999 The GNU Source-Level Debugger''.
3001 *** Changes in GDB 5.3:
3003 * GNU/Linux shared library multi-threaded performance improved.
3005 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3006 `/proc', in preference to `ptrace' for memory reads. This may result
3007 in an improvement in the start-up time of multi-threaded, shared
3008 library applications when run under GDB. One GDB user writes: ``loads
3009 shared libs like mad''.
3011 * ``gdbserver'' now supports multi-threaded applications on some targets
3013 Support for debugging multi-threaded applications which use
3014 the GNU/Linux LinuxThreads package has been added for
3015 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3016 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3018 * GDB now supports C/C++ preprocessor macros.
3020 GDB now expands preprocessor macro invocations in C/C++ expressions,
3021 and provides various commands for showing macro definitions and how
3024 The new command `macro expand EXPRESSION' expands any macro
3025 invocations in expression, and shows the result.
3027 The new command `show macro MACRO-NAME' shows the definition of the
3028 macro named MACRO-NAME, and where it was defined.
3030 Most compilers don't include information about macros in the debugging
3031 information by default. In GCC 3.1, for example, you need to compile
3032 your program with the options `-gdwarf-2 -g3'. If the macro
3033 information is present in the executable, GDB will read it.
3035 * Multi-arched targets.
3037 DEC Alpha (partial) alpha*-*-*
3038 DEC VAX (partial) vax-*-*
3040 National Semiconductor NS32000 (partial) ns32k-*-*
3041 Motorola 68000 (partial) m68k-*-*
3042 Motorola MCORE mcore-*-*
3046 Fujitsu FRV architecture added by Red Hat frv*-*-*
3049 * New native configurations
3051 Alpha NetBSD alpha*-*-netbsd*
3052 SH NetBSD sh*-*-netbsdelf*
3053 MIPS NetBSD mips*-*-netbsd*
3054 UltraSPARC NetBSD sparc64-*-netbsd*
3056 * OBSOLETE configurations and files
3058 Configurations that have been declared obsolete in this release have
3059 been commented out. Unless there is activity to revive these
3060 configurations, the next release of GDB will have their sources
3061 permanently REMOVED.
3063 Mitsubishi D30V d30v-*-*
3064 OS/9000 i[34]86-*-os9k
3065 IBM AIX PS/2 i[3456]86-*-aix
3066 Fujitsu FR30 fr30-*-elf*
3067 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3068 Argonaut Risc Chip (ARC) arc-*-*
3069 i386 running Mach 3.0 i[3456]86-*-mach3*
3070 i386 running Mach i[3456]86-*-mach*
3071 i386 running OSF/1 i[3456]86-*osf1mk*
3072 HP/Apollo 68k Family m68*-apollo*-sysv*,
3074 m68*-hp-bsd*, m68*-hp-hpux*
3075 I960 with MON960 i960-*-coff
3077 * OBSOLETE languages
3079 CHILL, a Pascal like language used by telecommunications companies.
3081 * REMOVED configurations and files
3083 AMD 29k family via UDI a29k-amd-udi, udi29k
3084 A29K VxWorks a29k-*-vxworks
3085 AMD 29000 embedded, using EBMON a29k-none-none
3086 AMD 29000 embedded with COFF a29k-none-coff
3087 AMD 29000 embedded with a.out a29k-none-aout
3089 testsuite/gdb.hp/gdb.threads-hp/ directory
3091 * New command "set max-user-call-depth <nnn>"
3093 This command allows the user to limit the call depth of user-defined
3094 commands. The default is 1024.
3096 * Changes in FreeBSD/i386 native debugging.
3098 Support for the "generate-core-file" has been added.
3100 * New commands "dump", "append", and "restore".
3102 These commands allow data to be copied from target memory
3103 to a bfd-format or binary file (dump and append), and back
3104 from a file into memory (restore).
3106 * Improved "next/step" support on multi-processor Alpha Tru64.
3108 The previous single-step mechanism could cause unpredictable problems,
3109 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3110 of a software single-step mechanism prevents this.
3112 *** Changes in GDB 5.2.1:
3120 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3121 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3122 Fix, by Joel Brobecker imported from mainline.
3124 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3125 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3126 Fix, by Fred Fish, imported from mainline.
3128 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3129 Surprisingly enough, it works now.
3130 By Michal Ludvig, imported from mainline.
3132 i386 hardware watchpoint support:
3133 avoid misses on second run for some targets.
3134 By Pierre Muller, imported from mainline.
3136 *** Changes in GDB 5.2:
3138 * New command "set trust-readonly-sections on[off]".
3140 This command is a hint that tells gdb that read-only sections
3141 really are read-only (ie. that their contents will not change).
3142 In this mode, gdb will go to the object file rather than the
3143 target to read memory from read-only sections (such as ".text").
3144 This can be a significant performance improvement on some
3145 (notably embedded) targets.
3147 * New command "generate-core-file" (or "gcore").
3149 This new gdb command allows the user to drop a core file of the child
3150 process state at any time. So far it's been implemented only for
3151 GNU/Linux and Solaris, but should be relatively easily ported to other
3152 hosts. Argument is core file name (defaults to core.<pid>).
3154 * New command line option
3156 GDB now accepts --pid or -p followed by a process id.
3158 * Change in command line behavior -- corefiles vs. process ids.
3160 There is a subtle behavior in the way in which GDB handles
3161 command line arguments. The first non-flag argument is always
3162 a program to debug, but the second non-flag argument may either
3163 be a corefile or a process id. Previously, GDB would attempt to
3164 open the second argument as a corefile, and if that failed, would
3165 issue a superfluous error message and then attempt to attach it as
3166 a process. Now, if the second argument begins with a non-digit,
3167 it will be treated as a corefile. If it begins with a digit,
3168 GDB will attempt to attach it as a process, and if no such process
3169 is found, will then attempt to open it as a corefile.
3171 * Changes in ARM configurations.
3173 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3174 configuration is fully multi-arch.
3176 * New native configurations
3178 ARM NetBSD arm*-*-netbsd*
3179 x86 OpenBSD i[3456]86-*-openbsd*
3180 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3181 Sparc64 running FreeBSD sparc64-*-freebsd*
3185 Sanyo XStormy16 xstormy16-elf
3187 * OBSOLETE configurations and files
3189 Configurations that have been declared obsolete in this release have
3190 been commented out. Unless there is activity to revive these
3191 configurations, the next release of GDB will have their sources
3192 permanently REMOVED.
3194 AMD 29k family via UDI a29k-amd-udi, udi29k
3195 A29K VxWorks a29k-*-vxworks
3196 AMD 29000 embedded, using EBMON a29k-none-none
3197 AMD 29000 embedded with COFF a29k-none-coff
3198 AMD 29000 embedded with a.out a29k-none-aout
3200 testsuite/gdb.hp/gdb.threads-hp/ directory
3202 * REMOVED configurations and files
3204 TI TMS320C80 tic80-*-*
3206 PowerPC Solaris powerpcle-*-solaris*
3207 PowerPC Windows NT powerpcle-*-cygwin32
3208 PowerPC Netware powerpc-*-netware*
3209 Harris/CXUX m88k m88*-harris-cxux*
3210 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3211 ns32k-utek-sysv* ns32k-utek-*
3212 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3213 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3214 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3215 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3216 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3218 * Changes to command line processing
3220 The new `--args' feature can be used to specify command-line arguments
3221 for the inferior from gdb's command line.
3223 * Changes to key bindings
3225 There is a new `operate-and-get-next' function bound to `C-o'.
3227 *** Changes in GDB 5.1.1
3229 Fix compile problem on DJGPP.
3231 Fix a problem with floating-point registers on the i386 being
3234 Fix to stop GDB crashing on .debug_str debug info.
3236 Numerous documentation fixes.
3238 Numerous testsuite fixes.
3240 *** Changes in GDB 5.1:
3242 * New native configurations
3244 Alpha FreeBSD alpha*-*-freebsd*
3245 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3246 MIPS GNU/Linux mips*-*-linux*
3247 MIPS SGI Irix 6.x mips*-sgi-irix6*
3248 ia64 AIX ia64-*-aix*
3249 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3253 Motorola 68HC11 and 68HC12 m68hc11-elf
3255 UltraSparc running GNU/Linux sparc64-*-linux*
3257 * OBSOLETE configurations and files
3259 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3260 Harris/CXUX m88k m88*-harris-cxux*
3261 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3262 ns32k-utek-sysv* ns32k-utek-*
3263 TI TMS320C80 tic80-*-*
3265 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3266 PowerPC Solaris powerpcle-*-solaris*
3267 PowerPC Windows NT powerpcle-*-cygwin32
3268 PowerPC Netware powerpc-*-netware*
3269 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3270 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3271 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3272 Apple Macintosh (MPW) host N/A
3274 stuff.c (Program to stuff files into a specially prepared space in kdb)
3275 kdb-start.c (Main loop for the standalone kernel debugger)
3277 Configurations that have been declared obsolete in this release have
3278 been commented out. Unless there is activity to revive these
3279 configurations, the next release of GDB will have their sources
3280 permanently REMOVED.
3282 * REMOVED configurations and files
3284 Altos 3068 m68*-altos-*
3285 Convex c1-*-*, c2-*-*
3287 ARM RISCix arm-*-* (as host)
3291 * GDB has been converted to ISO C.
3293 GDB's source code has been converted to ISO C. In particular, the
3294 sources are fully protoized, and rely on standard headers being
3299 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3301 * The MI enabled by default.
3303 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3304 revised and enabled by default. Packages which use GDB as a debugging
3305 engine behind a UI or another front end are encouraged to switch to
3306 using the GDB/MI interface, instead of the old annotations interface
3307 which is now deprecated.
3309 * Support for debugging Pascal programs.
3311 GDB now includes support for debugging Pascal programs. The following
3312 main features are supported:
3314 - Pascal-specific data types such as sets;
3316 - automatic recognition of Pascal sources based on file-name
3319 - Pascal-style display of data types, variables, and functions;
3321 - a Pascal expression parser.
3323 However, some important features are not yet supported.
3325 - Pascal string operations are not supported at all;
3327 - there are some problems with boolean types;
3329 - Pascal type hexadecimal constants are not supported
3330 because they conflict with the internal variables format;
3332 - support for Pascal objects and classes is not full yet;
3334 - unlike Pascal, GDB is case-sensitive for symbol names.
3336 * Changes in completion.
3338 Commands such as `shell', `run' and `set args', which pass arguments
3339 to inferior programs, now complete on file names, similar to what
3340 users expect at the shell prompt.
3342 Commands which accept locations, such as `disassemble', `print',
3343 `breakpoint', `until', etc. now complete on filenames as well as
3344 program symbols. Thus, if you type "break foob TAB", and the source
3345 files linked into the programs include `foobar.c', that file name will
3346 be one of the candidates for completion. However, file names are not
3347 considered for completion after you typed a colon that delimits a file
3348 name from a name of a function in that file, as in "break foo.c:bar".
3350 `set demangle-style' completes on available demangling styles.
3352 * New platform-independent commands:
3354 It is now possible to define a post-hook for a command as well as a
3355 hook that runs before the command. For more details, see the
3356 documentation of `hookpost' in the GDB manual.
3358 * Changes in GNU/Linux native debugging.
3360 Support for debugging multi-threaded programs has been completely
3361 revised for all platforms except m68k and sparc. You can now debug as
3362 many threads as your system allows you to have.
3364 Attach/detach is supported for multi-threaded programs.
3366 Support for SSE registers was added for x86. This doesn't work for
3367 multi-threaded programs though.
3369 * Changes in MIPS configurations.
3371 Multi-arch support is enabled for all MIPS configurations.
3373 GDB can now be built as native debugger on SGI Irix 6.x systems for
3374 debugging n32 executables. (Debugging 64-bit executables is not yet
3377 * Unified support for hardware watchpoints in all x86 configurations.
3379 Most (if not all) native x86 configurations support hardware-assisted
3380 breakpoints and watchpoints in a unified manner. This support
3381 implements debug register sharing between watchpoints, which allows to
3382 put a virtually infinite number of watchpoints on the same address,
3383 and also supports watching regions up to 16 bytes with several debug
3386 The new maintenance command `maintenance show-debug-regs' toggles
3387 debugging print-outs in functions that insert, remove, and test
3388 watchpoints and hardware breakpoints.
3390 * Changes in the DJGPP native configuration.
3392 New command ``info dos sysinfo'' displays assorted information about
3393 the CPU, OS, memory, and DPMI server.
3395 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3396 display information about segment descriptors stored in GDT, LDT, and
3399 New commands ``info dos pde'' and ``info dos pte'' display entries
3400 from Page Directory and Page Tables (for now works with CWSDPMI only).
3401 New command ``info dos address-pte'' displays the Page Table entry for
3402 a given linear address.
3404 GDB can now pass command lines longer than 126 characters to the
3405 program being debugged (requires an update to the libdbg.a library
3406 which is part of the DJGPP development kit).
3408 DWARF2 debug info is now supported.
3410 It is now possible to `step' and `next' through calls to `longjmp'.
3412 * Changes in documentation.
3414 All GDB documentation was converted to GFDL, the GNU Free
3415 Documentation License.
3417 Tracepoints-related commands are now fully documented in the GDB
3420 TUI, the Text-mode User Interface, is now documented in the manual.
3422 Tracepoints-related commands are now fully documented in the GDB
3425 The "GDB Internals" manual now has an index. It also includes
3426 documentation of `ui_out' functions, GDB coding standards, x86
3427 hardware watchpoints, and memory region attributes.
3429 * GDB's version number moved to ``version.in''
3431 The Makefile variable VERSION has been replaced by the file
3432 ``version.in''. People creating GDB distributions should update the
3433 contents of this file.
3437 GUD support is now a standard part of the EMACS distribution.
3439 *** Changes in GDB 5.0:
3441 * Improved support for debugging FP programs on x86 targets
3443 Unified and much-improved support for debugging floating-point
3444 programs on all x86 targets. In particular, ``info float'' now
3445 displays the FP registers in the same format on all x86 targets, with
3446 greater level of detail.
3448 * Improvements and bugfixes in hardware-assisted watchpoints
3450 It is now possible to watch array elements, struct members, and
3451 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3452 on x86 targets no longer erroneously trigger when the address is
3455 * Improvements in the native DJGPP version of GDB
3457 The distribution now includes all the scripts and auxiliary files
3458 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3459 machines ``out of the box''.
3461 The DJGPP version can now debug programs that use signals. It is
3462 possible to catch signals that happened in the debuggee, deliver
3463 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3464 would kill the program being debugged.) Programs that hook hardware
3465 interrupts (keyboard, timer, etc.) can also be debugged.
3467 It is now possible to debug DJGPP programs that redirect their
3468 standard handles or switch them to raw (as opposed to cooked) mode, or
3469 even close them. The command ``run < foo > bar'' works as expected,
3470 and ``info terminal'' reports useful information about the debuggee's
3471 terminal, including raw/cooked mode, redirection, etc.
3473 The DJGPP version now uses termios functions for console I/O, which
3474 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3477 DOS-style file names with drive letters are now fully supported by
3480 It is now possible to debug DJGPP programs that switch their working
3481 directory. It is also possible to rerun the debuggee any number of
3482 times without restarting GDB; thus, you can use the same setup,
3483 breakpoints, etc. for many debugging sessions.
3485 * New native configurations
3487 ARM GNU/Linux arm*-*-linux*
3488 PowerPC GNU/Linux powerpc-*-linux*
3492 Motorola MCore mcore-*-*
3493 x86 VxWorks i[3456]86-*-vxworks*
3494 PowerPC VxWorks powerpc-*-vxworks*
3495 TI TMS320C80 tic80-*-*
3497 * OBSOLETE configurations
3499 Altos 3068 m68*-altos-*
3500 Convex c1-*-*, c2-*-*
3502 ARM RISCix arm-*-* (as host)
3505 Configurations that have been declared obsolete will be commented out,
3506 but the code will be left in place. If there is no activity to revive
3507 these configurations before the next release of GDB, the sources will
3508 be permanently REMOVED.
3510 * Gould support removed
3512 Support for the Gould PowerNode and NP1 has been removed.
3514 * New features for SVR4
3516 On SVR4 native platforms (such as Solaris), if you attach to a process
3517 without first loading a symbol file, GDB will now attempt to locate and
3518 load symbols from the running process's executable file.
3520 * Many C++ enhancements
3522 C++ support has been greatly improved. Overload resolution now works properly
3523 in almost all cases. RTTI support is on the way.
3525 * Remote targets can connect to a sub-program
3527 A popen(3) style serial-device has been added. This device starts a
3528 sub-process (such as a stand-alone simulator) and then communicates
3529 with that. The sub-program to run is specified using the syntax
3530 ``|<program> <args>'' vis:
3532 (gdb) set remotedebug 1
3533 (gdb) target extended-remote |mn10300-elf-sim program-args
3535 * MIPS 64 remote protocol
3537 A long standing bug in the mips64 remote protocol where by GDB
3538 expected certain 32 bit registers (ex SR) to be transfered as 32
3539 instead of 64 bits has been fixed.
3541 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3542 added to provide backward compatibility with older versions of GDB.
3544 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3546 The command ``set remotebinarydownload'' command has been replaced by
3547 ``set remote X-packet''. Other commands in ``set remote'' family
3548 include ``set remote P-packet''.
3550 * Breakpoint commands accept ranges.
3552 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3553 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3554 ``tracepoint passcount'' also accepts a range of tracepoints.
3556 * ``apropos'' command added.
3558 The ``apropos'' command searches through command names and
3559 documentation strings, printing out matches, making it much easier to
3560 try to find a command that does what you are looking for.
3564 A new machine oriented interface (MI) has been added to GDB. This
3565 interface is designed for debug environments running GDB as a separate
3566 process. This is part of the long term libGDB project. See the
3567 "GDB/MI" chapter of the GDB manual for further information. It can be
3568 enabled by configuring with:
3570 .../configure --enable-gdbmi
3572 *** Changes in GDB-4.18:
3574 * New native configurations
3576 HP-UX 10.20 hppa*-*-hpux10.20
3577 HP-UX 11.x hppa*-*-hpux11.0*
3578 M68K GNU/Linux m68*-*-linux*
3582 Fujitsu FR30 fr30-*-elf*
3583 Intel StrongARM strongarm-*-*
3584 Mitsubishi D30V d30v-*-*
3586 * OBSOLETE configurations
3588 Gould PowerNode, NP1 np1-*-*, pn-*-*
3590 Configurations that have been declared obsolete will be commented out,
3591 but the code will be left in place. If there is no activity to revive
3592 these configurations before the next release of GDB, the sources will
3593 be permanently REMOVED.
3597 As a compatibility experiment, GDB's source files buildsym.h and
3598 buildsym.c have been converted to pure standard C, no longer
3599 containing any K&R compatibility code. We believe that all systems in
3600 use today either come with a standard C compiler, or have a GCC port
3601 available. If this is not true, please report the affected
3602 configuration to bug-gdb@gnu.org immediately. See the README file for
3603 information about getting a standard C compiler if you don't have one
3608 GDB now uses readline 2.2.
3610 * set extension-language
3612 You can now control the mapping between filename extensions and source
3613 languages by using the `set extension-language' command. For instance,
3614 you can ask GDB to treat .c files as C++ by saying
3615 set extension-language .c c++
3616 The command `info extensions' lists all of the recognized extensions
3617 and their associated languages.
3619 * Setting processor type for PowerPC and RS/6000
3621 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3622 you can use the `set processor' command to specify what variant of the
3623 PowerPC family you are debugging. The command
3627 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3628 following PowerPC and RS6000 variants:
3630 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3631 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3633 403GC IBM PowerPC 403GC
3634 505 Motorola PowerPC 505
3635 860 Motorola PowerPC 860 or 850
3636 601 Motorola PowerPC 601
3637 602 Motorola PowerPC 602
3638 603 Motorola/IBM PowerPC 603 or 603e
3639 604 Motorola PowerPC 604 or 604e
3640 750 Motorola/IBM PowerPC 750 or 750
3642 At the moment, this command just tells GDB what to name the
3643 special-purpose processor registers. Since almost all the affected
3644 registers are inaccessible to user-level programs, this command is
3645 only useful for remote debugging in its present form.
3649 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3650 more extensive support for HP-UX. Added features include shared
3651 library support, kernel threads and hardware watchpoints for 11.00,
3652 support for HP's ANSI C and C++ compilers, and a compatibility mode
3653 for xdb and dbx commands.
3657 HP's donation includes the new concept of catchpoints, which is a
3658 generalization of the old catch command. On HP-UX, it is now possible
3659 to catch exec, fork, and vfork, as well as library loading.
3661 This means that the existing catch command has changed; its first
3662 argument now specifies the type of catch to be set up. See the
3663 output of "help catch" for a list of catchpoint types.
3665 * Debugging across forks
3667 On HP-UX, you can choose which process to debug when a fork() happens
3672 HP has donated a curses-based terminal user interface (TUI). To get
3673 it, build with --enable-tui. Although this can be enabled for any
3674 configuration, at present it only works for native HP debugging.
3676 * GDB remote protocol additions
3678 A new protocol packet 'X' that writes binary data is now available.
3679 Default behavior is to try 'X', then drop back to 'M' if the stub
3680 fails to respond. The settable variable `remotebinarydownload'
3681 allows explicit control over the use of 'X'.
3683 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3684 full 64-bit address. The command
3686 set remoteaddresssize 32
3688 can be used to revert to the old behaviour. For existing remote stubs
3689 the change should not be noticed, as the additional address information
3692 In order to assist in debugging stubs, you may use the maintenance
3693 command `packet' to send any text string to the stub. For instance,
3695 maint packet heythere
3697 sends the packet "$heythere#<checksum>". Note that it is very easy to
3698 disrupt a debugging session by sending the wrong packet at the wrong
3701 The compare-sections command allows you to compare section data on the
3702 target to what is in the executable file without uploading or
3703 downloading, by comparing CRC checksums.
3705 * Tracing can collect general expressions
3707 You may now collect general expressions at tracepoints. This requires
3708 further additions to the target-side stub; see tracepoint.c and
3709 doc/agentexpr.texi for further details.
3711 * mask-address variable for Mips
3713 For Mips targets, you may control the zeroing of the upper 32 bits of
3714 a 64-bit address by entering `set mask-address on'. This is mainly
3715 of interest to users of embedded R4xxx and R5xxx processors.
3717 * Higher serial baud rates
3719 GDB's serial code now allows you to specify baud rates 57600, 115200,
3720 230400, and 460800 baud. (Note that your host system may not be able
3721 to achieve all of these rates.)
3725 The i960 configuration now includes an initial implementation of a
3726 builtin simulator, contributed by Jim Wilson.
3729 *** Changes in GDB-4.17:
3731 * New native configurations
3733 Alpha GNU/Linux alpha*-*-linux*
3734 Unixware 2.x i[3456]86-unixware2*
3735 Irix 6.x mips*-sgi-irix6*
3736 PowerPC GNU/Linux powerpc-*-linux*
3737 PowerPC Solaris powerpcle-*-solaris*
3738 Sparc GNU/Linux sparc-*-linux*
3739 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3743 Argonaut Risc Chip (ARC) arc-*-*
3744 Hitachi H8/300S h8300*-*-*
3745 Matsushita MN10200 w/simulator mn10200-*-*
3746 Matsushita MN10300 w/simulator mn10300-*-*
3747 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3748 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3749 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3750 Mitsubishi D10V w/simulator d10v-*-*
3751 Mitsubishi M32R/D w/simulator m32r-*-elf*
3752 Tsqware Sparclet sparclet-*-*
3753 NEC V850 w/simulator v850-*-*
3755 * New debugging protocols
3757 ARM with RDI protocol arm*-*-*
3758 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3759 DDB and LSI variants of PMON protocol mips*-*-*
3760 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3761 PowerPC with SDS protocol powerpc{,le}-*-eabi
3762 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3766 All configurations can now understand and use the DWARF 2 debugging
3767 format. The choice is automatic, if the symbol file contains DWARF 2
3772 GDB now includes basic Java language support. This support is
3773 only useful with Java compilers that produce native machine code.
3775 * solib-absolute-prefix and solib-search-path
3777 For SunOS and SVR4 shared libraries, you may now set the prefix for
3778 loading absolute shared library symbol files, and the search path for
3779 locating non-absolute shared library symbol files.
3781 * Live range splitting
3783 GDB can now effectively debug code for which GCC has performed live
3784 range splitting as part of its optimization. See gdb/doc/LRS for
3785 more details on the expected format of the stabs information.
3789 GDB's support for the GNU Hurd, including thread debugging, has been
3790 updated to work with current versions of the Hurd.
3794 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3795 instruction set. ARM GDB automatically detects when Thumb
3796 instructions are in use, and adjusts disassembly and backtracing
3801 GDB's MIPS target configurations now handle the MIP16 16-bit
3806 GDB now includes support for overlays; if an executable has been
3807 linked such that multiple sections are based at the same address, GDB
3808 will decide which section to use for symbolic info. You can choose to
3809 control the decision manually, using overlay commands, or implement
3810 additional target-side support and use "overlay load-target" to bring
3811 in the overlay mapping. Do "help overlay" for more detail.
3815 The command "info symbol <address>" displays information about
3816 the symbol at the specified address.
3820 The standard remote protocol now includes an extension that allows
3821 asynchronous collection and display of trace data. This requires
3822 extensive support in the target-side debugging stub. Tracing mode
3823 includes a new interaction mode in GDB and new commands: see the
3824 file tracepoint.c for more details.
3828 Configurations for embedded MIPS now include a simulator contributed
3829 by Cygnus Solutions. The simulator supports the instruction sets
3830 of most MIPS variants.
3834 Sparc configurations may now include the ERC32 simulator contributed
3835 by the European Space Agency. The simulator is not built into
3836 Sparc targets by default; configure with --enable-sim to include it.
3840 For target configurations that may include multiple variants of a
3841 basic architecture (such as MIPS and SH), you may now set the
3842 architecture explicitly. "set arch" sets, "info arch" lists
3843 the possible architectures.
3845 *** Changes in GDB-4.16:
3847 * New native configurations
3849 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3850 M68K NetBSD m68k-*-netbsd*
3851 PowerPC AIX 4.x powerpc-*-aix*
3852 PowerPC MacOS powerpc-*-macos*
3853 PowerPC Windows NT powerpcle-*-cygwin32
3854 RS/6000 AIX 4.x rs6000-*-aix4*
3858 ARM with RDP protocol arm-*-*
3859 I960 with MON960 i960-*-coff
3860 MIPS VxWorks mips*-*-vxworks*
3861 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3862 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3864 Matra Sparclet sparclet-*-*
3868 The powerpc-eabi configuration now includes the PSIM simulator,
3869 contributed by Andrew Cagney, with assistance from Mike Meissner.
3870 PSIM is a very elaborate model of the PowerPC, including not only
3871 basic instruction set execution, but also details of execution unit
3872 performance and I/O hardware. See sim/ppc/README for more details.
3876 GDB now works with Solaris 2.5.
3878 * Windows 95/NT native
3880 GDB will now work as a native debugger on Windows 95 and Windows NT.
3881 To build it from source, you must use the "gnu-win32" environment,
3882 which uses a DLL to emulate enough of Unix to run the GNU tools.
3883 Further information, binaries, and sources are available at
3884 ftp.cygnus.com, under pub/gnu-win32.
3886 * dont-repeat command
3888 If a user-defined command includes the command `dont-repeat', then the
3889 command will not be repeated if the user just types return. This is
3890 useful if the command is time-consuming to run, so that accidental
3891 extra keystrokes don't run the same command many times.
3893 * Send break instead of ^C
3895 The standard remote protocol now includes an option to send a break
3896 rather than a ^C to the target in order to interrupt it. By default,
3897 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3899 * Remote protocol timeout
3901 The standard remote protocol includes a new variable `remotetimeout'
3902 that allows you to set the number of seconds before GDB gives up trying
3903 to read from the target. The default value is 2.
3905 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3907 By default GDB will automatically keep track of objects as they are
3908 loaded and unloaded by the dynamic linker. By using the command `set
3909 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3910 when shared library events occur, thus allowing you to set breakpoints
3911 in shared libraries which are explicitly loaded by the inferior.
3913 Note this feature does not work on hpux8. On hpux9 you must link
3914 /usr/lib/end.o into your program. This feature should work
3915 automatically on hpux10.
3917 * Irix 5.x hardware watchpoint support
3919 Irix 5 configurations now support the use of hardware watchpoints.
3921 * Mips protocol "SYN garbage limit"
3923 When debugging a Mips target using the `target mips' protocol, you
3924 may set the number of characters that GDB will ignore by setting
3925 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3926 every character. The default value is 1050.
3928 * Recording and replaying remote debug sessions
3930 If you set `remotelogfile' to the name of a file, gdb will write to it
3931 a recording of a remote debug session. This recording may then be
3932 replayed back to gdb using "gdbreplay". See gdbserver/README for
3933 details. This is useful when you have a problem with GDB while doing
3934 remote debugging; you can make a recording of the session and send it
3935 to someone else, who can then recreate the problem.
3937 * Speedups for remote debugging
3939 GDB includes speedups for downloading and stepping MIPS systems using
3940 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3941 and more efficient S-record downloading.
3943 * Memory use reductions and statistics collection
3945 GDB now uses less memory and reports statistics about memory usage.
3946 Try the `maint print statistics' command, for example.
3948 *** Changes in GDB-4.15:
3950 * Psymtabs for XCOFF
3952 The symbol reader for AIX GDB now uses partial symbol tables. This
3953 can greatly improve startup time, especially for large executables.
3955 * Remote targets use caching
3957 Remote targets now use a data cache to speed up communication with the
3958 remote side. The data cache could lead to incorrect results because
3959 it doesn't know about volatile variables, thus making it impossible to
3960 debug targets which use memory mapped I/O devices. `set remotecache
3961 off' turns the the data cache off.
3963 * Remote targets may have threads
3965 The standard remote protocol now includes support for multiple threads
3966 in the target system, using new protocol commands 'H' and 'T'. See
3967 gdb/remote.c for details.
3971 If GDB is configured with `--enable-netrom', then it will include
3972 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3973 acts as though it is a bank of ROM on the target board, but you can
3974 write into it over the network. GDB's support consists only of
3975 support for fast loading into the emulated ROM; to debug, you must use
3976 another protocol, such as standard remote protocol. The usual
3977 sequence is something like
3979 target nrom <netrom-hostname>
3981 target remote <netrom-hostname>:1235
3985 GDB now includes support for the Apple Macintosh, as a host only. It
3986 may be run as either an MPW tool or as a standalone application, and
3987 it can debug through the serial port. All the usual GDB commands are
3988 available, but to the target command, you must supply "serial" as the
3989 device type instead of "/dev/ttyXX". See mpw-README in the main
3990 directory for more information on how to build. The MPW configuration
3991 scripts */mpw-config.in support only a few targets, and only the
3992 mips-idt-ecoff target has been tested.
3996 GDB configuration now uses autoconf. This is not user-visible,
3997 but does simplify configuration and building.
4001 GDB now supports hpux10.
4003 *** Changes in GDB-4.14:
4005 * New native configurations
4007 x86 FreeBSD i[345]86-*-freebsd
4008 x86 NetBSD i[345]86-*-netbsd
4009 NS32k NetBSD ns32k-*-netbsd
4010 Sparc NetBSD sparc-*-netbsd
4014 A29K VxWorks a29k-*-vxworks
4015 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4016 CPU32 EST-300 emulator m68*-*-est*
4017 PowerPC ELF powerpc-*-elf
4020 * Alpha OSF/1 support for procfs
4022 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4023 possible to attach to running processes. As the mounting of the /proc
4024 filesystem is optional on the Alpha, GDB automatically determines
4025 the availability of /proc during startup. This can lead to problems
4026 if /proc is unmounted after GDB has been started.
4028 * Arguments to user-defined commands
4030 User commands may accept up to 10 arguments separated by whitespace.
4031 Arguments are accessed within the user command via $arg0..$arg9. A
4034 print $arg0 + $arg1 + $arg2
4036 To execute the command use:
4039 Defines the command "adder" which prints the sum of its three arguments.
4040 Note the arguments are text substitutions, so they may reference variables,
4041 use complex expressions, or even perform inferior function calls.
4043 * New `if' and `while' commands
4045 This makes it possible to write more sophisticated user-defined
4046 commands. Both commands take a single argument, which is the
4047 expression to evaluate, and must be followed by the commands to
4048 execute, one per line, if the expression is nonzero, the list being
4049 terminated by the word `end'. The `if' command list may include an
4050 `else' word, which causes the following commands to be executed only
4051 if the expression is zero.
4053 * Fortran source language mode
4055 GDB now includes partial support for Fortran 77. It will recognize
4056 Fortran programs and can evaluate a subset of Fortran expressions, but
4057 variables and functions may not be handled correctly. GDB will work
4058 with G77, but does not yet know much about symbols emitted by other
4061 * Better HPUX support
4063 Most debugging facilities now work on dynamic executables for HPPAs
4064 running hpux9 or later. You can attach to running dynamically linked
4065 processes, but by default the dynamic libraries will be read-only, so
4066 for instance you won't be able to put breakpoints in them. To change
4067 that behavior do the following before running the program:
4073 This will cause the libraries to be mapped private and read-write.
4074 To revert to the normal behavior, do this:
4080 You cannot set breakpoints or examine data in the library until after
4081 the library is loaded if the function/data symbols do not have
4084 GDB can now also read debug symbols produced by the HP C compiler on
4085 HPPAs (sorry, no C++, Fortran or 68k support).
4087 * Target byte order now dynamically selectable
4089 You can choose which byte order to use with a target system, via the
4090 commands "set endian big" and "set endian little", and you can see the
4091 current setting by using "show endian". You can also give the command
4092 "set endian auto", in which case GDB will use the byte order
4093 associated with the executable. Currently, only embedded MIPS
4094 configurations support dynamic selection of target byte order.
4096 * New DOS host serial code
4098 This version uses DPMI interrupts to handle buffered I/O, so you
4099 no longer need to run asynctsr when debugging boards connected to
4102 *** Changes in GDB-4.13:
4104 * New "complete" command
4106 This lists all the possible completions for the rest of the line, if it
4107 were to be given as a command itself. This is intended for use by emacs.
4109 * Trailing space optional in prompt
4111 "set prompt" no longer adds a space for you after the prompt you set. This
4112 allows you to set a prompt which ends in a space or one that does not.
4114 * Breakpoint hit counts
4116 "info break" now displays a count of the number of times the breakpoint
4117 has been hit. This is especially useful in conjunction with "ignore"; you
4118 can ignore a large number of breakpoint hits, look at the breakpoint info
4119 to see how many times the breakpoint was hit, then run again, ignoring one
4120 less than that number, and this will get you quickly to the last hit of
4123 * Ability to stop printing at NULL character
4125 "set print null-stop" will cause GDB to stop printing the characters of
4126 an array when the first NULL is encountered. This is useful when large
4127 arrays actually contain only short strings.
4129 * Shared library breakpoints
4131 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4132 breakpoints in shared libraries before the executable is run.
4134 * Hardware watchpoints
4136 There is a new hardware breakpoint for the watch command for sparclite
4137 targets. See gdb/sparclite/hw_breakpoint.note.
4139 Hardware watchpoints are also now supported under GNU/Linux.
4143 Annotations have been added. These are for use with graphical interfaces,
4144 and are still experimental. Currently only gdba.el uses these.
4146 * Improved Irix 5 support
4148 GDB now works properly with Irix 5.2.
4150 * Improved HPPA support
4152 GDB now works properly with the latest GCC and GAS.
4154 * New native configurations
4156 Sequent PTX4 i[34]86-sequent-ptx4
4157 HPPA running OSF/1 hppa*-*-osf*
4158 Atari TT running SVR4 m68*-*-sysv4*
4159 RS/6000 LynxOS rs6000-*-lynxos*
4163 OS/9000 i[34]86-*-os9k
4164 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4167 * Hitachi SH7000 and E7000-PC ICE support
4169 There is now support for communicating with the Hitachi E7000-PC ICE.
4170 This is available automatically when GDB is configured for the SH.
4174 As usual, a variety of small fixes and improvements, both generic
4175 and configuration-specific. See the ChangeLog for more detail.
4177 *** Changes in GDB-4.12:
4179 * Irix 5 is now supported
4183 GDB-4.12 on the HPPA has a number of changes which make it unable
4184 to debug the output from the currently released versions of GCC and
4185 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4186 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4187 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4190 *** Changes in GDB-4.11:
4192 * User visible changes:
4196 The "set remotedebug" option is now consistent between the mips remote
4197 target, remote targets using the gdb-specific protocol, UDI (AMD's
4198 debug protocol for the 29k) and the 88k bug monitor. It is now an
4199 integer specifying a debug level (normally 0 or 1, but 2 means more
4200 debugging info for the mips target).
4202 * DEC Alpha native support
4204 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4205 debug info, but GDB works fairly well with the DEC compiler and should
4206 work with a future GCC release. See the README file for a few
4207 Alpha-specific notes.
4209 * Preliminary thread implementation
4211 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4213 * LynxOS native and target support for 386
4215 This release has been hosted on LynxOS 2.2, and also can be configured
4216 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4219 * Improvements in C++ mangling/demangling.
4221 This release has much better g++ debugging, specifically in name
4222 mangling/demangling, virtual function calls, print virtual table,
4223 call methods, ...etc.
4225 *** Changes in GDB-4.10:
4227 * User visible changes:
4229 Remote debugging using the GDB-specific (`target remote') protocol now
4230 supports the `load' command. This is only useful if you have some
4231 other way of getting the stub to the target system, and you can put it
4232 somewhere in memory where it won't get clobbered by the download.
4234 Filename completion now works.
4236 When run under emacs mode, the "info line" command now causes the
4237 arrow to point to the line specified. Also, "info line" prints
4238 addresses in symbolic form (as well as hex).
4240 All vxworks based targets now support a user settable option, called
4241 vxworks-timeout. This option represents the number of seconds gdb
4242 should wait for responses to rpc's. You might want to use this if
4243 your vxworks target is, perhaps, a slow software simulator or happens
4244 to be on the far side of a thin network line.
4248 This release contains support for using a DEC alpha as a GDB host for
4249 cross debugging. Native alpha debugging is not supported yet.
4252 *** Changes in GDB-4.9:
4256 This is the first GDB release which is accompanied by a matching testsuite.
4257 The testsuite requires installation of dejagnu, which should be available
4258 via ftp from most sites that carry GNU software.
4262 'Cfront' style demangling has had its name changed to 'ARM' style, to
4263 emphasize that it was written from the specifications in the C++ Annotated
4264 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4265 disclaimers, it still generated too much confusion with users attempting to
4266 use gdb with AT&T cfront.
4270 GDB now uses a standard remote interface to a simulator library.
4271 So far, the library contains simulators for the Zilog Z8001/2, the
4272 Hitachi H8/300, H8/500 and Super-H.
4274 * New targets supported
4276 H8/300 simulator h8300-hitachi-hms or h8300hms
4277 H8/500 simulator h8500-hitachi-hms or h8500hms
4278 SH simulator sh-hitachi-hms or sh
4279 Z8000 simulator z8k-zilog-none or z8ksim
4280 IDT MIPS board over serial line mips-idt-ecoff
4282 Cross-debugging to GO32 targets is supported. It requires a custom
4283 version of the i386-stub.c module which is integrated with the
4284 GO32 memory extender.
4286 * New remote protocols
4288 MIPS remote debugging protocol.
4290 * New source languages supported
4292 This version includes preliminary support for Chill, a Pascal like language
4293 used by telecommunications companies. Chill support is also being integrated
4294 into the GNU compiler, but we don't know when it will be publically available.
4297 *** Changes in GDB-4.8:
4299 * HP Precision Architecture supported
4301 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4302 version of this support was available as a set of patches from the
4303 University of Utah. GDB does not support debugging of programs
4304 compiled with the HP compiler, because HP will not document their file
4305 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4306 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4308 Many problems in the preliminary version have been fixed.
4310 * Faster and better demangling
4312 We have improved template demangling and fixed numerous bugs in the GNU style
4313 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4314 character types (wchar_t) are now supported. Demangling of each symbol is now
4315 only done once, and is cached when the symbol table for a file is read in.
4316 This results in a small increase in memory usage for C programs, a moderate
4317 increase in memory usage for C++ programs, and a fantastic speedup in
4320 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4321 from the specifications in the Annotated Reference Manual, which AT&T's
4322 compiler does not actually implement.
4324 * G++ multiple inheritance compiler problem
4326 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4327 inheritance lattices was reworked to properly discover ambiguities. We
4328 recently found an example which causes this new algorithm to fail in a
4329 very subtle way, producing bad debug information for those classes.
4330 The file 'gcc.patch' (in this directory) can be applied to gcc to
4331 circumvent the problem. A future GCC release will contain a complete
4334 The previous G++ debug info problem (mentioned below for the gdb-4.7
4335 release) is fixed in gcc version 2.3.2.
4337 * Improved configure script
4339 The `configure' script will now attempt to guess your system type if
4340 you don't supply a host system type. The old scheme of supplying a
4341 host system triplet is preferable over using this. All the magic is
4342 done in the new `config.guess' script. Examine it for details.
4344 We have also brought our configure script much more in line with the FSF's
4345 version. It now supports the --with-xxx options. In particular,
4346 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4347 The resulting GDB will not be able to read arbitrary object file formats --
4348 only the format ``expected'' to be used on the configured target system.
4349 We hope to make this the default in a future release.
4351 * Documentation improvements
4353 There's new internal documentation on how to modify GDB, and how to
4354 produce clean changes to the code. We implore people to read it
4355 before submitting changes.
4357 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4358 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4359 `info' files are also provided. To build `info' files from scratch,
4360 you will need the latest `makeinfo' release, which will be available in
4361 a future texinfo-X.Y release.
4363 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4364 We're not sure exactly which versions have this problem, but it has
4365 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4366 or better. If that isn't possible, there is a patch in
4367 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4368 around this problem.
4372 GDB now supports array constants that can be used in expressions typed in by
4373 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4374 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4377 The new directory `gdb/sparclite' contains a program that demonstrates
4378 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4380 * New native hosts supported
4382 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4383 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4385 * New targets supported
4387 AMD 29k family via UDI a29k-amd-udi or udi29k
4389 * New file formats supported
4391 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4392 HPUX core files, and SCO 3.2v2 core files.
4396 Attaching to processes now works again; thanks for the many bug reports.
4398 We have also stomped on a bunch of core dumps caused by
4399 printf_filtered("%s") problems.
4401 We eliminated a copyright problem on the rpc and ptrace header files
4402 for VxWorks, which was discovered at the last minute during the 4.7
4403 release. You should now be able to build a VxWorks GDB.
4405 You can now interrupt gdb while an attached process is running. This
4406 will cause the attached process to stop, and give control back to GDB.
4408 We fixed problems caused by using too many file descriptors
4409 for reading symbols from object files and libraries. This was
4410 especially a problem for programs that used many (~100) shared
4413 The `step' command now only enters a subroutine if there is line number
4414 information for the subroutine. Otherwise it acts like the `next'
4415 command. Previously, `step' would enter subroutines if there was
4416 any debugging information about the routine. This avoids problems
4417 when using `cc -g1' on MIPS machines.
4419 * Internal improvements
4421 GDB's internal interfaces have been improved to make it easier to support
4422 debugging of multiple languages in the future.
4424 GDB now uses a common structure for symbol information internally.
4425 Minimal symbols (derived from linkage symbols in object files), partial
4426 symbols (from a quick scan of debug information), and full symbols
4427 contain a common subset of information, making it easier to write
4428 shared code that handles any of them.
4430 * New command line options
4432 We now accept --silent as an alias for --quiet.
4436 The memory-mapped-malloc library is now licensed under the GNU Library
4437 General Public License.
4439 *** Changes in GDB-4.7:
4441 * Host/native/target split
4443 GDB has had some major internal surgery to untangle the support for
4444 hosts and remote targets. Now, when you configure GDB for a remote
4445 target, it will no longer load in all of the support for debugging
4446 local programs on the host. When fully completed and tested, this will
4447 ensure that arbitrary host/target combinations are possible.
4449 The primary conceptual shift is to separate the non-portable code in
4450 GDB into three categories. Host specific code is required any time GDB
4451 is compiled on that host, regardless of the target. Target specific
4452 code relates to the peculiarities of the target, but can be compiled on
4453 any host. Native specific code is everything else: it can only be
4454 built when the host and target are the same system. Child process
4455 handling and core file support are two common `native' examples.
4457 GDB's use of /proc for controlling Unix child processes is now cleaner.
4458 It has been split out into a single module under the `target_ops' vector,
4459 plus two native-dependent functions for each system that uses /proc.
4461 * New hosts supported
4463 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4464 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4465 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4467 * New targets supported
4469 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4470 68030 and CPU32 m68030-*-*, m68332-*-*
4472 * New native hosts supported
4474 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4475 (386bsd is not well tested yet)
4476 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4478 * New file formats supported
4480 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4481 supports reading of `a.out.adobe' object files, which are an a.out
4482 format extended with minimal information about multiple sections.
4486 `show copying' is the same as the old `info copying'.
4487 `show warranty' is the same as `info warrantee'.
4488 These were renamed for consistency. The old commands continue to work.
4490 `info handle' is a new alias for `info signals'.
4492 You can now define pre-command hooks, which attach arbitrary command
4493 scripts to any command. The commands in the hook will be executed
4494 prior to the user's command. You can also create a hook which will be
4495 executed whenever the program stops. See gdb.texinfo.
4499 We now deal with Cfront style name mangling, and can even extract type
4500 info from mangled symbols. GDB can automatically figure out which
4501 symbol mangling style your C++ compiler uses.
4503 Calling of methods and virtual functions has been improved as well.
4507 The crash that occured when debugging Sun Ansi-C compiled binaries is
4508 fixed. This was due to mishandling of the extra N_SO stabs output
4511 We also finally got Ultrix 4.2 running in house, and fixed core file
4512 support, with help from a dozen people on the net.
4514 John M. Farrell discovered that the reason that single-stepping was so
4515 slow on all of the Mips based platforms (primarily SGI and DEC) was
4516 that we were trying to demangle and lookup a symbol used for internal
4517 purposes on every instruction that was being stepped through. Changing
4518 the name of that symbol so that it couldn't be mistaken for a C++
4519 mangled symbol sped things up a great deal.
4521 Rich Pixley sped up symbol lookups in general by getting much smarter
4522 about when C++ symbol mangling is necessary. This should make symbol
4523 completion (TAB on the command line) much faster. It's not as fast as
4524 we'd like, but it's significantly faster than gdb-4.6.
4528 A new user controllable variable 'call_scratch_address' can
4529 specify the location of a scratch area to be used when GDB
4530 calls a function in the target. This is necessary because the
4531 usual method of putting the scratch area on the stack does not work
4532 in systems that have separate instruction and data spaces.
4534 We integrated changes to support the 29k UDI (Universal Debugger
4535 Interface), but discovered at the last minute that we didn't have all
4536 of the appropriate copyright paperwork. We are working with AMD to
4537 resolve this, and hope to have it available soon.
4541 We have sped up the remote serial line protocol, especially for targets
4542 with lots of registers. It now supports a new `expedited status' ('T')
4543 message which can be used in place of the existing 'S' status message.
4544 This allows the remote stub to send only the registers that GDB
4545 needs to make a quick decision about single-stepping or conditional
4546 breakpoints, eliminating the need to fetch the entire register set for
4547 each instruction being stepped through.
4549 The GDB remote serial protocol now implements a write-through cache for
4550 registers, only re-reading the registers if the target has run.
4552 There is also a new remote serial stub for SPARC processors. You can
4553 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4554 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4555 processor with a serial port.
4559 Configure.in files have become much easier to read and modify. A new
4560 `table driven' format makes it more obvious what configurations are
4561 supported, and what files each one uses.
4565 There is a new opcodes library which will eventually contain all of the
4566 disassembly routines and opcode tables. At present, it only contains
4567 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4568 disassembler (binutils/objdump) to share these routines.
4570 The libiberty library is now copylefted under the GNU Library General
4571 Public License. This allows more liberal use, and was done so libg++
4572 can use it. This makes no difference to GDB, since the Library License
4573 grants all the rights from the General Public License.
4577 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4578 reference to the stabs symbol info used by the debugger. It is (as far
4579 as we know) the only published document on this fascinating topic. We
4580 encourage you to read it, compare it to the stabs information on your
4581 system, and send improvements on the document in general (to
4582 bug-gdb@prep.ai.mit.edu).
4584 And, of course, many bugs have been fixed.
4587 *** Changes in GDB-4.6:
4589 * Better support for C++ function names
4591 GDB now accepts as input the "demangled form" of C++ overloaded function
4592 names and member function names, and can do command completion on such names
4593 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4594 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4595 Make use of command completion, it is your friend.
4597 GDB also now accepts a variety of C++ mangled symbol formats. They are
4598 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4599 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4600 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4601 for the list of formats.
4603 * G++ symbol mangling problem
4605 Recent versions of gcc have a bug in how they emit debugging information for
4606 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4607 directory) can be applied to gcc to fix the problem. Alternatively, if you
4608 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4609 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4610 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4613 * New 'maintenance' command
4615 All of the commands related to hacking GDB internals have been moved out of
4616 the main command set, and now live behind the 'maintenance' command. This
4617 can also be abbreviated as 'mt'. The following changes were made:
4619 dump-me -> maintenance dump-me
4620 info all-breakpoints -> maintenance info breakpoints
4621 printmsyms -> maintenance print msyms
4622 printobjfiles -> maintenance print objfiles
4623 printpsyms -> maintenance print psymbols
4624 printsyms -> maintenance print symbols
4626 The following commands are new:
4628 maintenance demangle Call internal GDB demangler routine to
4629 demangle a C++ link name and prints the result.
4630 maintenance print type Print a type chain for a given symbol
4632 * Change to .gdbinit file processing
4634 We now read the $HOME/.gdbinit file before processing the argv arguments
4635 (e.g. reading symbol files or core files). This allows global parameters to
4636 be set, which will apply during the symbol reading. The ./.gdbinit is still
4637 read after argv processing.
4639 * New hosts supported
4641 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4643 GNU/Linux support i386-unknown-linux or linux
4645 We are also including code to support the HP/PA running BSD and HPUX. This
4646 is almost guaranteed not to work, as we didn't have time to test or build it
4647 for this release. We are including it so that the more adventurous (or
4648 masochistic) of you can play with it. We also had major problems with the
4649 fact that the compiler that we got from HP doesn't support the -g option.
4652 * New targets supported
4654 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4656 * More smarts about finding #include files
4658 GDB now remembers the compilation directory for all include files, and for
4659 all files from which C is generated (like yacc and lex sources). This
4660 greatly improves GDB's ability to find yacc/lex sources, and include files,
4661 especially if you are debugging your program from a directory different from
4662 the one that contains your sources.
4664 We also fixed a bug which caused difficulty with listing and setting
4665 breakpoints in include files which contain C code. (In the past, you had to
4666 try twice in order to list an include file that you hadn't looked at before.)
4668 * Interesting infernals change
4670 GDB now deals with arbitrary numbers of sections, where the symbols for each
4671 section must be relocated relative to that section's landing place in the
4672 target's address space. This work was needed to support ELF with embedded
4673 stabs used by Solaris-2.0.
4675 * Bug fixes (of course!)
4677 There have been loads of fixes for the following things:
4678 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4679 i960, stabs, DOS(GO32), procfs, etc...
4681 See the ChangeLog for details.
4683 *** Changes in GDB-4.5:
4685 * New machines supported (host and target)
4687 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4689 SGI Irix-4.x mips-sgi-irix4 or iris4
4691 * New malloc package
4693 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4694 Mmalloc is capable of handling mutiple heaps of memory. It is also
4695 capable of saving a heap to a file, and then mapping it back in later.
4696 This can be used to greatly speedup the startup of GDB by using a
4697 pre-parsed symbol table which lives in a mmalloc managed heap. For
4698 more details, please read mmalloc/mmalloc.texi.
4702 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4703 'help info proc' for details.
4705 * MIPS ecoff symbol table format
4707 The code that reads MIPS symbol table format is now supported on all hosts.
4708 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4711 * File name changes for MS-DOS
4713 Many files in the config directories have been renamed to make it easier to
4714 support GDB on MS-DOSe systems (which have very restrictive file name
4715 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4716 environment) is close to working but has some remaining problems. Note
4717 that debugging of DOS programs is not supported, due to limitations
4718 in the ``operating system'', but it can be used to host cross-debugging.
4720 * Cross byte order fixes
4722 Many fixes have been made to support cross debugging of Sparc and MIPS
4723 targets from hosts whose byte order differs.
4725 * New -mapped and -readnow options
4727 If memory-mapped files are available on your system through the 'mmap'
4728 system call, you can use the -mapped option on the `file' or
4729 `symbol-file' commands to cause GDB to write the symbols from your
4730 program into a reusable file. If the program you are debugging is
4731 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4732 Future GDB debugging sessions will notice the presence of this file,
4733 and will quickly map in symbol information from it, rather than reading
4734 the symbol table from the executable program. Using the '-mapped'
4735 option in a GDB `file' or `symbol-file' command has the same effect as
4736 starting GDB with the '-mapped' command-line option.
4738 You can cause GDB to read the entire symbol table immediately by using
4739 the '-readnow' option with any of the commands that load symbol table
4740 information (or on the GDB command line). This makes the command
4741 slower, but makes future operations faster.
4743 The -mapped and -readnow options are typically combined in order to
4744 build a `fred.syms' file that contains complete symbol information.
4745 A simple GDB invocation to do nothing but build a `.syms' file for future
4748 gdb -batch -nx -mapped -readnow programname
4750 The `.syms' file is specific to the host machine on which GDB is run.
4751 It holds an exact image of GDB's internal symbol table. It cannot be
4752 shared across multiple host platforms.
4754 * longjmp() handling
4756 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4757 siglongjmp() without losing control. This feature has not yet been ported to
4758 all systems. It currently works on many 386 platforms, all MIPS-based
4759 platforms (SGI, DECstation, etc), and Sun3/4.
4763 Preliminary work has been put in to support the new Solaris OS from Sun. At
4764 this time, it can control and debug processes, but it is not capable of
4769 As always, many many bug fixes. The major areas were with g++, and mipsread.
4770 People using the MIPS-based platforms should experience fewer mysterious
4771 crashes and trashed symbol tables.
4773 *** Changes in GDB-4.4:
4775 * New machines supported (host and target)
4777 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4779 BSD Reno on Vax vax-dec-bsd
4780 Ultrix on Vax vax-dec-ultrix
4782 * New machines supported (target)
4784 AMD 29000 embedded, using EBMON a29k-none-none
4788 GDB continues to improve its handling of C++. `References' work better.
4789 The demangler has also been improved, and now deals with symbols mangled as
4790 per the Annotated C++ Reference Guide.
4792 GDB also now handles `stabs' symbol information embedded in MIPS
4793 `ecoff' symbol tables. Since the ecoff format was not easily
4794 extensible to handle new languages such as C++, this appeared to be a
4795 good way to put C++ debugging info into MIPS binaries. This option
4796 will be supported in the GNU C compiler, version 2, when it is
4799 * New features for SVR4
4801 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4802 shared libraries. Debugging dynamically linked programs should present
4803 only minor differences from debugging statically linked programs.
4805 The `info proc' command will print out information about any process
4806 on an SVR4 system (including the one you are debugging). At the moment,
4807 it prints the address mappings of the process.
4809 If you bring up GDB on another SVR4 system, please send mail to
4810 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4812 * Better dynamic linking support in SunOS
4814 Reading symbols from shared libraries which contain debugging symbols
4815 now works properly. However, there remain issues such as automatic
4816 skipping of `transfer vector' code during function calls, which
4817 make it harder to debug code in a shared library, than to debug the
4818 same code linked statically.
4822 GDB is now using the latest `getopt' routines from the FSF. This
4823 version accepts the -- prefix for options with long names. GDB will
4824 continue to accept the old forms (-option and +option) as well.
4825 Various single letter abbreviations for options have been explicity
4826 added to the option table so that they won't get overshadowed in the
4827 future by other options that begin with the same letter.
4831 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4832 Many assorted bugs have been handled. Many more remain to be handled.
4833 See the various ChangeLog files (primarily in gdb and bfd) for details.
4836 *** Changes in GDB-4.3:
4838 * New machines supported (host and target)
4840 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4841 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4842 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4844 * Almost SCO Unix support
4846 We had hoped to support:
4847 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4848 (except for core file support), but we discovered very late in the release
4849 that it has problems with process groups that render gdb unusable. Sorry
4850 about that. I encourage people to fix it and post the fixes.
4852 * Preliminary ELF and DWARF support
4854 GDB can read ELF object files on System V Release 4, and can handle
4855 debugging records for C, in DWARF format, in ELF files. This support
4856 is preliminary. If you bring up GDB on another SVR4 system, please
4857 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4862 GDB now uses the latest `readline' library. One user-visible change
4863 is that two tabs will list possible command completions, which previously
4864 required typing M-? (meta-question mark, or ESC ?).
4868 The `stepi' bug that many of you noticed has been squashed.
4869 Many bugs in C++ have been handled. Many more remain to be handled.
4870 See the various ChangeLog files (primarily in gdb and bfd) for details.
4872 * State of the MIPS world (in case you wondered):
4874 GDB can understand the symbol tables emitted by the compilers
4875 supplied by most vendors of MIPS-based machines, including DEC. These
4876 symbol tables are in a format that essentially nobody else uses.
4878 Some versions of gcc come with an assembler post-processor called
4879 mips-tfile. This program is required if you want to do source-level
4880 debugging of gcc-compiled programs. I believe FSF does not ship
4881 mips-tfile with gcc version 1, but it will eventually come with gcc
4884 Debugging of g++ output remains a problem. g++ version 1.xx does not
4885 really support it at all. (If you're lucky, you should be able to get
4886 line numbers and stack traces to work, but no parameters or local
4887 variables.) With some work it should be possible to improve the
4890 When gcc version 2 is released, you will have somewhat better luck.
4891 However, even then you will get confusing results for inheritance and
4894 We will eventually provide full debugging of g++ output on
4895 DECstations. This will probably involve some kind of stabs-in-ecoff
4896 encapulation, but the details have not been worked out yet.
4899 *** Changes in GDB-4.2:
4901 * Improved configuration
4903 Only one copy of `configure' exists now, and it is not self-modifying.
4904 Porting BFD is simpler.
4908 The `step' and `next' commands now only stop at the first instruction
4909 of a source line. This prevents the multiple stops that used to occur
4910 in switch statements, for-loops, etc. `Step' continues to stop if a
4911 function that has debugging information is called within the line.
4915 Lots of small bugs fixed. More remain.
4917 * New host supported (not target)
4919 Intel 386 PC clone running Mach i386-none-mach
4922 *** Changes in GDB-4.1:
4924 * Multiple source language support
4926 GDB now has internal scaffolding to handle several source languages.
4927 It determines the type of each source file from its filename extension,
4928 and will switch expression parsing and number formatting to match the
4929 language of the function in the currently selected stack frame.
4930 You can also specifically set the language to be used, with
4931 `set language c' or `set language modula-2'.
4935 GDB now has preliminary support for the GNU Modula-2 compiler,
4936 currently under development at the State University of New York at
4937 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4938 continue through the fall of 1991 and into 1992.
4940 Other Modula-2 compilers are currently not supported, and attempting to
4941 debug programs compiled with them will likely result in an error as the
4942 symbol table is read. Feel free to work on it, though!
4944 There are hooks in GDB for strict type checking and range checking,
4945 in the `Modula-2 philosophy', but they do not currently work.
4949 GDB can now write to executable and core files (e.g. patch
4950 a variable's value). You must turn this switch on, specify
4951 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4952 by assigning a new value to a variable. Modifications take
4955 * Automatic SunOS shared library reading
4957 When you run your program, GDB automatically determines where its
4958 shared libraries (if any) have been loaded, and reads their symbols.
4959 The `share' command is no longer needed. This also works when
4960 examining core files.
4964 You can specify the number of lines that the `list' command shows.
4967 * New machines supported (host and target)
4969 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4970 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4971 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4973 * New hosts supported (not targets)
4975 IBM RT/PC: romp-ibm-aix or rtpc
4977 * New targets supported (not hosts)
4979 AMD 29000 embedded with COFF a29k-none-coff
4980 AMD 29000 embedded with a.out a29k-none-aout
4981 Ultracomputer remote kernel debug a29k-nyu-kern
4983 * New remote interfaces
4989 *** Changes in GDB-4.0:
4993 Wide output is wrapped at good places to make the output more readable.
4995 Gdb now supports cross-debugging from a host machine of one type to a
4996 target machine of another type. Communication with the target system
4997 is over serial lines. The ``target'' command handles connecting to the
4998 remote system; the ``load'' command will download a program into the
4999 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5000 also supports debugging of realtime processes running under VxWorks,
5001 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5002 stub on the target system.
5004 New CPUs supported include the AMD 29000 and Intel 960.
5006 GDB now reads object files and symbol tables via a ``binary file''
5007 library, which allows a single copy of GDB to debug programs of multiple
5008 object file types such as a.out and coff.
5010 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5011 refcard.dvi and refcard.ps are available to format it).
5014 * Control-Variable user interface simplified
5016 All variables that control the operation of the debugger can be set
5017 by the ``set'' command, and displayed by the ``show'' command.
5019 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5020 ``Show prompt'' produces the response:
5021 Gdb's prompt is new-gdb=>.
5023 What follows are the NEW set commands. The command ``help set'' will
5024 print a complete list of old and new set commands. ``help set FOO''
5025 will give a longer description of the variable FOO. ``show'' will show
5026 all of the variable descriptions and their current settings.
5028 confirm on/off: Enables warning questions for operations that are
5029 hard to recover from, e.g. rerunning the program while
5030 it is already running. Default is ON.
5032 editing on/off: Enables EMACS style command line editing
5033 of input. Previous lines can be recalled with
5034 control-P, the current line can be edited with control-B,
5035 you can search for commands with control-R, etc.
5038 history filename NAME: NAME is where the gdb command history
5039 will be stored. The default is .gdb_history,
5040 or the value of the environment variable
5043 history size N: The size, in commands, of the command history. The
5044 default is 256, or the value of the environment variable
5047 history save on/off: If this value is set to ON, the history file will
5048 be saved after exiting gdb. If set to OFF, the
5049 file will not be saved. The default is OFF.
5051 history expansion on/off: If this value is set to ON, then csh-like
5052 history expansion will be performed on
5053 command line input. The default is OFF.
5055 radix N: Sets the default radix for input and output. It can be set
5056 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5057 in the current radix, so "set radix 10" is always a no-op.
5059 height N: This integer value is the number of lines on a page. Default
5060 is 24, the current `stty rows'' setting, or the ``li#''
5061 setting from the termcap entry matching the environment
5064 width N: This integer value is the number of characters on a line.
5065 Default is 80, the current `stty cols'' setting, or the ``co#''
5066 setting from the termcap entry matching the environment
5069 Note: ``set screensize'' is obsolete. Use ``set height'' and
5070 ``set width'' instead.
5072 print address on/off: Print memory addresses in various command displays,
5073 such as stack traces and structure values. Gdb looks
5074 more ``symbolic'' if you turn this off; it looks more
5075 ``machine level'' with it on. Default is ON.
5077 print array on/off: Prettyprint arrays. New convenient format! Default
5080 print demangle on/off: Print C++ symbols in "source" form if on,
5083 print asm-demangle on/off: Same, for assembler level printouts
5086 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5089 * Support for Epoch Environment.
5091 The epoch environment is a version of Emacs v18 with windowing. One
5092 new command, ``inspect'', is identical to ``print'', except that if you
5093 are running in the epoch environment, the value is printed in its own
5097 * Support for Shared Libraries
5099 GDB can now debug programs and core files that use SunOS shared libraries.
5100 Symbols from a shared library cannot be referenced
5101 before the shared library has been linked with the program (this
5102 happens after you type ``run'' and before the function main() is entered).
5103 At any time after this linking (including when examining core files
5104 from dynamically linked programs), gdb reads the symbols from each
5105 shared library when you type the ``sharedlibrary'' command.
5106 It can be abbreviated ``share''.
5108 sharedlibrary REGEXP: Load shared object library symbols for files
5109 matching a unix regular expression. No argument
5110 indicates to load symbols for all shared libraries.
5112 info sharedlibrary: Status of loaded shared libraries.
5117 A watchpoint stops execution of a program whenever the value of an
5118 expression changes. Checking for this slows down execution
5119 tremendously whenever you are in the scope of the expression, but is
5120 quite useful for catching tough ``bit-spreader'' or pointer misuse
5121 problems. Some machines such as the 386 have hardware for doing this
5122 more quickly, and future versions of gdb will use this hardware.
5124 watch EXP: Set a watchpoint (breakpoint) for an expression.
5126 info watchpoints: Information about your watchpoints.
5128 delete N: Deletes watchpoint number N (same as breakpoints).
5129 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5130 enable N: Re-enables watchpoint number N (same as breakpoints).
5133 * C++ multiple inheritance
5135 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5138 * C++ exception handling
5140 Gdb now supports limited C++ exception handling. Besides the existing
5141 ability to breakpoint on an exception handler, gdb can breakpoint on
5142 the raising of an exception (before the stack is peeled back to the
5145 catch FOO: If there is a FOO exception handler in the dynamic scope,
5146 set a breakpoint to catch exceptions which may be raised there.
5147 Multiple exceptions (``catch foo bar baz'') may be caught.
5149 info catch: Lists all exceptions which may be caught in the
5150 current stack frame.
5153 * Minor command changes
5155 The command ``call func (arg, arg, ...)'' now acts like the print
5156 command, except it does not print or save a value if the function's result
5157 is void. This is similar to dbx usage.
5159 The ``up'' and ``down'' commands now always print the frame they end up
5160 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5161 frames without printing.
5163 * New directory command
5165 'dir' now adds directories to the FRONT of the source search path.
5166 The path starts off empty. Source files that contain debug information
5167 about the directory in which they were compiled can be found even
5168 with an empty path; Sun CC and GCC include this information. If GDB can't
5169 find your source file in the current directory, type "dir .".
5171 * Configuring GDB for compilation
5173 For normal use, type ``./configure host''. See README or gdb.texinfo
5176 GDB now handles cross debugging. If you are remotely debugging between
5177 two different machines, type ``./configure host -target=targ''.
5178 Host is the machine where GDB will run; targ is the machine
5179 where the program that you are debugging will run.