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 * New Python-based convenience functions:
22 ** $_memeq(buf1, buf2, length)
23 ** $_streq(str1, str2)
25 ** $_regex(str, regex)
27 * The 'cd' command now defaults to using '~' (the home directory) if not
30 * The command 'forward-search' can now be abbreviated as 'fo'.
32 * New configure options
34 --enable-libmcheck/--disable-libmcheck
35 By default, development versions are built with -lmcheck on hosts
36 that support it, in order to help track memory corruption issues.
37 Release versions, on the other hand, are built without -lmcheck
38 by default. The --enable-libmcheck/--disable-libmcheck configure
39 options allow the user to override that default.
41 * New commands (for set/show, see "New options" below)
44 List the BFDs known to GDB.
46 python-interactive [command]
48 Start a Python interactive prompt, or evaluate the optional command
49 and print the result of expressions.
52 "py" is a new alias for "python".
56 ** For the Renesas Super-H architecture, the "regs" command has been removed
57 (has been deprecated in GDB 7.5), and "info all-registers" should be used
62 set print type methods (on|off)
63 show print type methods
64 Control whether method declarations are displayed by "ptype".
65 The default is to show them.
67 set print type typedefs (on|off)
68 show print type typedefs
69 Control whether typedef definitions are displayed by "ptype".
70 The default is to show them.
74 ** Command parameter changes are now notified using new async record
76 ** Trace frame changes caused by command "tfind" are now notified using
77 new async record "=traceframe-changed".
78 ** The creation and deletion of trace state variables are now notified
79 using new async records "=tsv-created" and "=tsv-deleted".
80 ** The start and stop of process record are now notified using new
81 async record "=record-started" and "=record-stopped".
82 ** Memory changes are now notified using new async record
84 ** The data-disassemble command response will include a "fullname" field
85 containing the absolute file name when GDB can determine it and source
88 *** Changes in GDB 7.5
90 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
91 for more x32 ABI info.
93 * GDB now supports access to MIPS DSP registers on Linux targets.
95 * GDB now supports debugging microMIPS binaries.
97 * The "info os" command on GNU/Linux can now display information on
98 several new classes of objects managed by the operating system:
99 "info os procgroups" lists process groups
100 "info os files" lists file descriptors
101 "info os sockets" lists internet-domain sockets
102 "info os shm" lists shared-memory regions
103 "info os semaphores" lists semaphores
104 "info os msg" lists message queues
105 "info os modules" lists loaded kernel modules
107 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
108 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
109 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
110 options and inspect the probe arguments using the new $_probe_arg family
111 of convenience variables. You can obtain more information about SystemTap
112 in <http://sourceware.org/systemtap/>.
114 * GDB now supports reversible debugging on ARM, it allows you to
115 debug basic ARM and THUMB instructions, and provides
116 record/replay support.
118 * The option "symbol-reloading" has been deleted as it is no longer used.
122 ** GDB commands implemented in Python can now be put in command class
125 ** The "maint set python print-stack on|off" is now deleted.
127 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
128 apply "flag enum"-style pretty-printing to any enum.
130 ** gdb.lookup_symbol can now work when there is no current frame.
132 ** gdb.Symbol now has a 'line' attribute, holding the line number in
133 the source at which the symbol was defined.
135 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
136 method 'value'. The former indicates whether the symbol needs a
137 frame in order to compute its value, and the latter computes the
140 ** A new method 'referenced_value' on gdb.Value objects which can
141 dereference pointer as well as C++ reference values.
143 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
144 which return the global and static blocks (as gdb.Block objects),
145 of the underlying symbol table, respectively.
147 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
148 object associated with a PC value.
150 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
151 of the address range occupied by code for the current source line.
153 * Go language support.
154 GDB now supports debugging programs written in the Go programming
157 * GDBserver now supports stdio connections.
158 E.g. (gdb) target remote | ssh myhost gdbserver - hello
160 * The binary "gdbtui" can no longer be built or installed.
161 Use "gdb -tui" instead.
163 * GDB will now print "flag" enums specially. A flag enum is one where
164 all the enumerator values have no bits in common when pairwise
165 "and"ed. When printing a value whose type is a flag enum, GDB will
166 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
167 (gdb) print (enum E) 3
170 * The filename part of a linespec will now match trailing components
171 of a source file name. For example, "break gcc/expr.c:1000" will
172 now set a breakpoint in build/gcc/expr.c, but not
175 * The "info proc" and "generate-core-file" commands will now also
176 work on remote targets connected to GDBserver on Linux.
178 * The command "info catch" has been removed. It has been disabled
181 * The "catch exception" and "catch assert" commands now accept
182 a condition at the end of the command, much like the "break"
183 command does. For instance:
185 (gdb) catch exception Constraint_Error if Barrier = True
187 Previously, it was possible to add a condition to such catchpoints,
188 but it had to be done as a second step, after the catchpoint had been
189 created, using the "condition" command.
191 * The "info static-tracepoint-marker" command will now also work on
192 native Linux targets with in-process agent.
194 * GDB can now set breakpoints on inlined functions.
196 * The .gdb_index section has been updated to include symbols for
197 inlined functions. GDB will ignore older .gdb_index sections by
198 default, which could cause symbol files to be loaded more slowly
199 until their .gdb_index sections can be recreated. The new command
200 "set use-deprecated-index-sections on" will cause GDB to use any older
201 .gdb_index sections it finds. This will restore performance, but the
202 ability to set breakpoints on inlined functions will be lost in symbol
203 files with older .gdb_index sections.
205 The .gdb_index section has also been updated to record more information
206 about each symbol. This speeds up the "info variables", "info functions"
207 and "info types" commands when used with programs having the .gdb_index
208 section, as well as speeding up debugging with shared libraries using
209 the .gdb_index section.
211 * Ada support for GDB/MI Variable Objects has been added.
213 * GDB can now support 'breakpoint always-inserted mode' in 'record'
218 ** New command -info-os is the MI equivalent of "info os".
220 ** Output logs ("set logging" and related) now include MI output.
224 ** "set use-deprecated-index-sections on|off"
225 "show use-deprecated-index-sections on|off"
226 Controls the use of deprecated .gdb_index sections.
228 ** "catch load" and "catch unload" can be used to stop when a shared
229 library is loaded or unloaded, respectively.
231 ** "enable count" can be used to auto-disable a breakpoint after
234 ** "info vtbl" can be used to show the virtual method tables for
235 C++ and Java objects.
237 ** "explore" and its sub commands "explore value" and "explore type"
238 can be used to reccursively explore values and types of
239 expressions. These commands are available only if GDB is
240 configured with '--with-python'.
242 ** "info auto-load" shows status of all kinds of auto-loaded files,
243 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
244 sequences of commands files, "info auto-load python-scripts"
245 shows status of auto-loading Python script files,
246 "info auto-load local-gdbinit" shows status of loading init file
247 (.gdbinit) from current directory and "info auto-load libthread-db" shows
248 status of inferior specific thread debugging shared library loading.
250 ** "info auto-load-scripts", "set auto-load-scripts on|off"
251 and "show auto-load-scripts" commands have been deprecated, use their
252 "info auto-load python-scripts", "set auto-load python-scripts on|off"
253 and "show auto-load python-scripts" counterparts instead.
255 ** "dprintf location,format,args..." creates a dynamic printf, which
256 is basically a breakpoint that does a printf and immediately
257 resumes your program's execution, so it is like a printf that you
258 can insert dynamically at runtime instead of at compiletime.
260 ** "set print symbol"
262 Controls whether GDB attempts to display the symbol, if any,
263 corresponding to addresses it prints. This defaults to "on", but
264 you can set it to "off" to restore GDB's previous behavior.
266 * Deprecated commands
268 ** For the Renesas Super-H architecture, the "regs" command has been
269 deprecated, and "info all-registers" should be used instead.
273 Renesas RL78 rl78-*-elf
274 HP OpenVMS ia64 ia64-hp-openvms*
276 * GDBserver supports evaluation of breakpoint conditions. When
277 support is advertised by GDBserver, GDB may be told to send the
278 breakpoint conditions in bytecode form to GDBserver. GDBserver
279 will only report the breakpoint trigger to GDB when its condition
285 show mips compression
286 Select the compressed ISA encoding used in functions that have no symbol
287 information available. The encoding can be set to either of:
290 and is updated automatically from ELF file flags if available.
292 set breakpoint condition-evaluation
293 show breakpoint condition-evaluation
294 Control whether breakpoint conditions are evaluated by GDB ("host") or by
295 GDBserver ("target"). Default option "auto" chooses the most efficient
297 This option can improve debugger efficiency depending on the speed of the
301 Disable auto-loading globally.
304 Show auto-loading setting of all kinds of auto-loaded files.
306 set auto-load gdb-scripts on|off
307 show auto-load gdb-scripts
308 Control auto-loading of GDB canned sequences of commands files.
310 set auto-load python-scripts on|off
311 show auto-load python-scripts
312 Control auto-loading of Python script files.
314 set auto-load local-gdbinit on|off
315 show auto-load local-gdbinit
316 Control loading of init file (.gdbinit) from current directory.
318 set auto-load libthread-db on|off
319 show auto-load libthread-db
320 Control auto-loading of inferior specific thread debugging shared library.
322 set auto-load scripts-directory <dir1>[:<dir2>...]
323 show auto-load scripts-directory
324 Set a list of directories from which to load auto-loaded scripts.
325 Automatically loaded Python scripts and GDB scripts are located in one
326 of the directories listed by this option.
327 The delimiter (':' above) may differ according to the host platform.
329 set auto-load safe-path <dir1>[:<dir2>...]
330 show auto-load safe-path
331 Set a list of directories from which it is safe to auto-load files.
332 The delimiter (':' above) may differ according to the host platform.
334 set debug auto-load on|off
336 Control display of debugging info for auto-loading the files above.
338 set dprintf-style gdb|call|agent
340 Control the way in which a dynamic printf is performed; "gdb"
341 requests a GDB printf command, while "call" causes dprintf to call a
342 function in the inferior. "agent" requests that the target agent
343 (such as GDBserver) do the printing.
345 set dprintf-function <expr>
346 show dprintf-function
347 set dprintf-channel <expr>
349 Set the function and optional first argument to the call when using
350 the "call" style of dynamic printf.
352 set disconnected-dprintf on|off
353 show disconnected-dprintf
354 Control whether agent-style dynamic printfs continue to be in effect
355 after GDB disconnects.
357 * New configure options
360 Configure default value for the 'set auto-load scripts-directory'
361 setting above. It defaults to '$debugdir:$datadir/auto-load',
362 $debugdir representing global debugging info directories (available
363 via 'show debug-file-directory') and $datadir representing GDB's data
364 directory (available via 'show data-directory').
366 --with-auto-load-safe-path
367 Configure default value for the 'set auto-load safe-path' setting
368 above. It defaults to the --with-auto-load-dir setting.
370 --without-auto-load-safe-path
371 Set 'set auto-load safe-path' to '/', effectively disabling this
376 z0/z1 conditional breakpoints extension
378 The z0/z1 breakpoint insertion packets have been extended to carry
379 a list of conditional expressions over to the remote stub depending on the
380 condition evaluation mode. The use of this extension can be controlled
381 via the "set remote conditional-breakpoints-packet" command.
385 Specify the signals which the remote stub may pass to the debugged
386 program without GDB involvement.
388 * New command line options
390 --init-command=FILE, -ix Like --command, -x but execute it
391 before loading inferior.
392 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
393 execute it before loading inferior.
395 *** Changes in GDB 7.4
397 * GDB now handles ambiguous linespecs more consistently; the existing
398 FILE:LINE support has been expanded to other types of linespecs. A
399 breakpoint will now be set on all matching locations in all
400 inferiors, and locations will be added or removed according to
403 * GDB now allows you to skip uninteresting functions and files when
404 stepping with the "skip function" and "skip file" commands.
406 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
407 and "show remote hardware-watchpoint-length-limit". These allows to
408 set or show the maximum length limit (in bytes) of a remote
409 target hardware watchpoint.
411 This allows e.g. to use "unlimited" hardware watchpoints with the
412 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
413 watchpoints are slower than real hardware watchpoints but are
414 significantly faster than gdb software watchpoints.
418 ** The register_pretty_printer function in module gdb.printing now takes
419 an optional `replace' argument. If True, the new printer replaces any
422 ** The "maint set python print-stack on|off" command has been
423 deprecated and will be deleted in GDB 7.5.
424 A new command: "set python print-stack none|full|message" has
425 replaced it. Additionally, the default for "print-stack" is
426 now "message", which just prints the error message without
429 ** A prompt substitution hook (prompt_hook) is now available to the
432 ** A new Python module, gdb.prompt has been added to the GDB Python
433 modules library. This module provides functionality for
434 escape sequences in prompts (used by set/show
435 extended-prompt). These escape sequences are replaced by their
438 ** Python commands and convenience-functions located in
439 'data-directory'/python/gdb/command and
440 'data-directory'/python/gdb/function are now automatically loaded
443 ** Blocks now provide four new attributes. global_block and
444 static_block will return the global and static blocks
445 respectively. is_static and is_global are boolean attributes
446 that indicate if the block is one of those two types.
448 ** Symbols now provide the "type" attribute, the type of the symbol.
450 ** The "gdb.breakpoint" function has been deprecated in favor of
453 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
454 of a function. This class is based on the "finish" command
455 available in the CLI.
457 ** Type objects for struct and union types now allow access to
458 the fields using standard Python dictionary (mapping) methods.
459 For example, "some_type['myfield']" now works, as does
462 ** A new event "gdb.new_objfile" has been added, triggered by loading a
465 ** A new function, "deep_items" has been added to the gdb.types
466 module in the GDB Python modules library. This function returns
467 an iterator over the fields of a struct or union type. Unlike
468 the standard Python "iteritems" method, it will recursively traverse
469 any anonymous fields.
473 ** "*stopped" events can report several new "reason"s, such as
476 ** Breakpoint changes are now notified using new async records, like
477 "=breakpoint-modified".
479 ** New command -ada-task-info.
481 * libthread-db-search-path now supports two special values: $sdir and $pdir.
482 $sdir specifies the default system locations of shared libraries.
483 $pdir specifies the directory where the libpthread used by the application
486 GDB no longer looks in $sdir and $pdir after it has searched the directories
487 mentioned in libthread-db-search-path. If you want to search those
488 directories, they must be specified in libthread-db-search-path.
489 The default value of libthread-db-search-path on GNU/Linux and Solaris
490 systems is now "$sdir:$pdir".
492 $pdir is not supported by gdbserver, it is currently ignored.
493 $sdir is supported by gdbserver.
495 * New configure option --with-iconv-bin.
496 When using the internationalization support like the one in the GNU C
497 library, GDB will invoke the "iconv" program to get a list of supported
498 character sets. If this program lives in a non-standard location, one can
499 use this option to specify where to find it.
501 * When natively debugging programs on PowerPC BookE processors running
502 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
503 watchpoints, which specify a mask in addition to an address to watch.
504 The mask specifies that some bits of an address (the bits which are
505 reset in the mask) should be ignored when matching the address accessed
506 by the inferior against the watchpoint address. See the "PowerPC Embedded"
507 section in the user manual for more details.
509 * The new option --once causes GDBserver to stop listening for connections once
510 the first connection is made. The listening port used by GDBserver will
511 become available after that.
513 * New commands "info macros" and "alias" have been added.
515 * New function parameters suffix @entry specifies value of function parameter
516 at the time the function got called. Entry values are available only since
522 "!" is now an alias of the "shell" command.
523 Note that no space is needed between "!" and SHELL COMMAND.
527 watch EXPRESSION mask MASK_VALUE
528 The watch command now supports the mask argument which allows creation
529 of masked watchpoints, if the current architecture supports this feature.
531 info auto-load-scripts [REGEXP]
532 This command was formerly named "maintenance print section-scripts".
533 It is now generally useful and is no longer a maintenance-only command.
535 info macro [-all] [--] MACRO
536 The info macro command has new options `-all' and `--'. The first for
537 printing all definitions of a macro. The second for explicitly specifying
538 the end of arguments and the beginning of the macro name in case the macro
539 name starts with a hyphen.
541 collect[/s] EXPRESSIONS
542 The tracepoint collect command now takes an optional modifier "/s"
543 that directs it to dereference pointer-to-character types and
544 collect the bytes of memory up to a zero byte. The behavior is
545 similar to what you see when you use the regular print command on a
546 string. An optional integer following the "/s" sets a bound on the
547 number of bytes that will be collected.
550 The trace start command now interprets any supplied arguments as a
551 note to be recorded with the trace run, with an effect similar to
552 setting the variable trace-notes.
555 The trace stop command now interprets any arguments as a note to be
556 mentioned along with the tstatus report that the trace was stopped
557 with a command. The effect is similar to setting the variable
560 * Tracepoints can now be enabled and disabled at any time after a trace
561 experiment has been started using the standard "enable" and "disable"
562 commands. It is now possible to start a trace experiment with no enabled
563 tracepoints; GDB will display a warning, but will allow the experiment to
564 begin, assuming that tracepoints will be enabled as needed while the trace
567 * Fast tracepoints on 32-bit x86-architectures can now be placed at
568 locations with 4-byte instructions, when they were previously
569 limited to locations with instructions of 5 bytes or longer.
573 set debug dwarf2-read
574 show debug dwarf2-read
575 Turns on or off display of debugging messages related to reading
576 DWARF debug info. The default is off.
578 set debug symtab-create
579 show debug symtab-create
580 Turns on or off display of debugging messages related to symbol table
581 creation. The default is off.
585 Set the GDB prompt, and allow escape sequences to be inserted to
586 display miscellaneous information (see 'help set extended-prompt'
587 for the list of sequences). This prompt (and any information
588 accessed through the escape sequences) is updated every time the
591 set print entry-values (both|compact|default|if-needed|no|only|preferred)
592 show print entry-values
593 Set printing of frame argument values at function entry. In some cases
594 GDB can determine the value of function argument which was passed by the
595 function caller, even if the value was modified inside the called function.
597 set debug entry-values
598 show debug entry-values
599 Control display of debugging info for determining frame argument values at
600 function entry and virtual tail call frames.
602 set basenames-may-differ
603 show basenames-may-differ
604 Set whether a source file may have multiple base names.
605 (A "base name" is the name of a file with the directory part removed.
606 Example: The base name of "/home/user/hello.c" is "hello.c".)
607 If set, GDB will canonicalize file names (e.g., expand symlinks)
608 before comparing them. Canonicalization is an expensive operation,
609 but it allows the same file be known by more than one base name.
610 If not set (the default), all source files are assumed to have just
611 one base name, and gdb will do file name comparisons more efficiently.
617 Set a user name and notes for the current and any future trace runs.
618 This is useful for long-running and/or disconnected traces, to
619 inform others (or yourself) as to who is running the trace, supply
620 contact information, or otherwise explain what is going on.
623 show trace-stop-notes
624 Set a note attached to the trace run, that is displayed when the
625 trace has been stopped by a tstop command. This is useful for
626 instance as an explanation, if you are stopping a trace run that was
627 started by someone else.
633 Dynamically enable a tracepoint in a started trace experiment.
637 Dynamically disable a tracepoint in a started trace experiment.
641 Set the user and notes of the trace run.
645 Query the current status of a tracepoint.
649 Query the minimum length of instruction at which a fast tracepoint may
652 * Dcache size (number of lines) and line-size are now runtime-configurable
653 via "set dcache line" and "set dcache line-size" commands.
657 Texas Instruments TMS320C6x tic6x-*-*
661 Renesas RL78 rl78-*-elf
663 *** Changes in GDB 7.3.1
665 * The build failure for NetBSD and OpenBSD targets have now been fixed.
667 *** Changes in GDB 7.3
669 * GDB has a new command: "thread find [REGEXP]".
670 It finds the thread id whose name, target id, or thread extra info
671 matches the given regular expression.
673 * The "catch syscall" command now works on mips*-linux* targets.
675 * The -data-disassemble MI command now supports modes 2 and 3 for
676 dumping the instruction opcodes.
678 * New command line options
680 -data-directory DIR Specify DIR as the "data-directory".
681 This is mostly for testing purposes.
683 * The "maint set python auto-load on|off" command has been renamed to
684 "set auto-load-scripts on|off".
686 * GDB has a new command: "set directories".
687 It is like the "dir" command except that it replaces the
688 source path list instead of augmenting it.
690 * GDB now understands thread names.
692 On GNU/Linux, "info threads" will display the thread name as set by
693 prctl or pthread_setname_np.
695 There is also a new command, "thread name", which can be used to
696 assign a name internally for GDB to display.
699 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
700 has been integrated into GDB.
704 ** The function gdb.Write now accepts an optional keyword 'stream'.
705 This keyword, when provided, will direct the output to either
706 stdout, stderr, or GDB's logging output.
708 ** Parameters can now be be sub-classed in Python, and in particular
709 you may implement the get_set_doc and get_show_doc functions.
710 This improves how Parameter set/show documentation is processed
711 and allows for more dynamic content.
713 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
714 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
715 have an is_valid method.
717 ** Breakpoints can now be sub-classed in Python, and in particular
718 you may implement a 'stop' function that is executed each time
719 the inferior reaches that breakpoint.
721 ** New function gdb.lookup_global_symbol looks up a global symbol.
723 ** GDB values in Python are now callable if the value represents a
724 function. For example, if 'some_value' represents a function that
725 takes two integer parameters and returns a value, you can call
726 that function like so:
728 result = some_value (10,20)
730 ** Module gdb.types has been added.
731 It contains a collection of utilities for working with gdb.Types objects:
732 get_basic_type, has_field, make_enum_dict.
734 ** Module gdb.printing has been added.
735 It contains utilities for writing and registering pretty-printers.
736 New classes: PrettyPrinter, SubPrettyPrinter,
737 RegexpCollectionPrettyPrinter.
738 New function: register_pretty_printer.
740 ** New commands "info pretty-printers", "enable pretty-printer" and
741 "disable pretty-printer" have been added.
743 ** gdb.parameter("directories") is now available.
745 ** New function gdb.newest_frame returns the newest frame in the
748 ** The gdb.InferiorThread class has a new "name" attribute. This
749 holds the thread's name.
751 ** Python Support for Inferior events.
752 Python scripts can add observers to be notified of events
753 occurring in the process being debugged.
754 The following events are currently supported:
755 - gdb.events.cont Continue event.
756 - gdb.events.exited Inferior exited event.
757 - gdb.events.stop Signal received, and Breakpoint hit events.
761 ** GDB now puts template parameters in scope when debugging in an
762 instantiation. For example, if you have:
764 template<int X> int func (void) { return X; }
766 then if you step into func<5>, "print X" will show "5". This
767 feature requires proper debuginfo support from the compiler; it
768 was added to GCC 4.5.
770 ** The motion commands "next", "finish", "until", and "advance" now
771 work better when exceptions are thrown. In particular, GDB will
772 no longer lose control of the inferior; instead, the GDB will
773 stop the inferior at the point at which the exception is caught.
774 This functionality requires a change in the exception handling
775 code that was introduced in GCC 4.5.
777 * GDB now follows GCC's rules on accessing volatile objects when
778 reading or writing target state during expression evaluation.
779 One notable difference to prior behavior is that "print x = 0"
780 no longer generates a read of x; the value of the assignment is
781 now always taken directly from the value being assigned.
783 * GDB now has some support for using labels in the program's source in
784 linespecs. For instance, you can use "advance label" to continue
785 execution to a label.
787 * GDB now has support for reading and writing a new .gdb_index
788 section. This section holds a fast index of DWARF debugging
789 information and can be used to greatly speed up GDB startup and
790 operation. See the documentation for `save gdb-index' for details.
792 * The "watch" command now accepts an optional "-location" argument.
793 When used, this causes GDB to watch the memory referred to by the
794 expression. Such a watchpoint is never deleted due to it going out
797 * GDB now supports thread debugging of core dumps on GNU/Linux.
799 GDB now activates thread debugging using the libthread_db library
800 when debugging GNU/Linux core dumps, similarly to when debugging
801 live processes. As a result, when debugging a core dump file, GDB
802 is now able to display pthread_t ids of threads. For example, "info
803 threads" shows the same output as when debugging the process when it
804 was live. In earlier releases, you'd see something like this:
807 * 1 LWP 6780 main () at main.c:10
809 While now you see this:
812 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
814 It is also now possible to inspect TLS variables when debugging core
817 When debugging a core dump generated on a machine other than the one
818 used to run GDB, you may need to point GDB at the correct
819 libthread_db library with the "set libthread-db-search-path"
820 command. See the user manual for more details on this command.
822 * When natively debugging programs on PowerPC BookE processors running
823 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
824 which stop execution of the inferior whenever it executes an instruction
825 at any address within the specified range. See the "PowerPC Embedded"
826 section in the user manual for more details.
828 * New features in the GDB remote stub, GDBserver
830 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
831 and i686 LynxOS (version 5.x).
833 ** GDBserver is now supported on Blackfin Linux.
835 * New native configurations
837 ia64 HP-UX ia64-*-hpux*
841 Analog Devices, Inc. Blackfin Processor bfin-*
843 * Ada task switching is now supported on sparc-elf targets when
844 debugging a program using the Ravenscar Profile. For more information,
845 see the "Tasking Support when using the Ravenscar Profile" section
846 in the GDB user manual.
848 * Guile support was removed.
850 * New features in the GNU simulator
852 ** The --map-info flag lists all known core mappings.
854 ** CFI flashes may be simulated via the "cfi" device.
856 *** Changes in GDB 7.2
858 * Shared library support for remote targets by default
860 When GDB is configured for a generic, non-OS specific target, like
861 for example, --target=arm-eabi or one of the many *-*-elf targets,
862 GDB now queries remote stubs for loaded shared libraries using the
863 `qXfer:libraries:read' packet. Previously, shared library support
864 was always disabled for such configurations.
868 ** Argument Dependent Lookup (ADL)
870 In C++ ADL lookup directs function search to the namespaces of its
871 arguments even if the namespace has not been imported.
881 Here the compiler will search for `foo' in the namespace of 'b'
882 and find A::foo. GDB now supports this. This construct is commonly
883 used in the Standard Template Library for operators.
885 ** Improved User Defined Operator Support
887 In addition to member operators, GDB now supports lookup of operators
888 defined in a namespace and imported with a `using' directive, operators
889 defined in the global scope, operators imported implicitly from an
890 anonymous namespace, and the ADL operators mentioned in the previous
892 GDB now also supports proper overload resolution for all the previously
893 mentioned flavors of operators.
895 ** static const class members
897 Printing of static const class members that are initialized in the
898 class definition has been fixed.
900 * Windows Thread Information Block access.
902 On Windows targets, GDB now supports displaying the Windows Thread
903 Information Block (TIB) structure. This structure is visible either
904 by using the new command `info w32 thread-information-block' or, by
905 dereferencing the new convenience variable named `$_tlb', a
906 thread-specific pointer to the TIB. This feature is also supported
907 when remote debugging using GDBserver.
911 Static tracepoints are calls in the user program into a tracing
912 library. One such library is a port of the LTTng kernel tracer to
913 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
914 When debugging with GDBserver, GDB now supports combining the GDB
915 tracepoint machinery with such libraries. For example: the user can
916 use GDB to probe a static tracepoint marker (a call from the user
917 program into the tracing library) with the new "strace" command (see
918 "New commands" below). This creates a "static tracepoint" in the
919 breakpoint list, that can be manipulated with the same feature set
920 as fast and regular tracepoints. E.g., collect registers, local and
921 global variables, collect trace state variables, and define
922 tracepoint conditions. In addition, the user can collect extra
923 static tracepoint marker specific data, by collecting the new
924 $_sdata internal variable. When analyzing the trace buffer, you can
925 inspect $_sdata like any other variable available to GDB. For more
926 information, see the "Tracepoints" chapter in GDB user manual. New
927 remote packets have been defined to support static tracepoints, see
928 the "New remote packets" section below.
930 * Better reconstruction of tracepoints after disconnected tracing
932 GDB will attempt to download the original source form of tracepoint
933 definitions when starting a trace run, and then will upload these
934 upon reconnection to the target, resulting in a more accurate
935 reconstruction of the tracepoints that are in use on the target.
939 You can now exercise direct control over the ways that GDB can
940 affect your program. For instance, you can disallow the setting of
941 breakpoints, so that the program can run continuously (assuming
942 non-stop mode). In addition, the "observer" variable is available
943 to switch all of the different controls; in observer mode, GDB
944 cannot affect the target's behavior at all, which is useful for
945 tasks like diagnosing live systems in the field.
947 * The new convenience variable $_thread holds the number of the
954 Return the address of the Windows Thread Information Block of a given thread.
958 In response to several of the tracepoint packets, the target may now
959 also respond with a number of intermediate `qRelocInsn' request
960 packets before the final result packet, to have GDB handle
961 relocating an instruction to execute at a different address. This
962 is particularly useful for stubs that support fast tracepoints. GDB
963 reports support for this feature in the qSupported packet.
967 List static tracepoint markers in the target program.
971 List static tracepoint markers at a given address in the target
974 qXfer:statictrace:read
976 Read the static trace data collected (by a `collect $_sdata'
977 tracepoint action). The remote stub reports support for this packet
978 to gdb's qSupported query.
982 Send the current settings of GDB's permission flags.
986 Send part of the source (textual) form of a tracepoint definition,
987 which includes location, conditional, and action list.
989 * The source command now accepts a -s option to force searching for the
990 script in the source search path even if the script name specifies
993 * New features in the GDB remote stub, GDBserver
995 - GDBserver now support tracepoints (including fast tracepoints, and
996 static tracepoints). The feature is currently supported by the
997 i386-linux and amd64-linux builds. See the "Tracepoints support
998 in gdbserver" section in the manual for more information.
1000 GDBserver JIT compiles the tracepoint's conditional agent
1001 expression bytecode into native code whenever possible for low
1002 overhead dynamic tracepoints conditionals. For such tracepoints,
1003 an expression that examines program state is evaluated when the
1004 tracepoint is reached, in order to determine whether to capture
1005 trace data. If the condition is simple and false, processing the
1006 tracepoint finishes very quickly and no data is gathered.
1008 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1009 for static tracepoints support.
1011 - GDBserver now supports x86_64 Windows 64-bit debugging.
1013 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1014 it understands register description.
1016 * The --batch flag now disables pagination and queries.
1018 * X86 general purpose registers
1020 GDB now supports reading/writing byte, word and double-word x86
1021 general purpose registers directly. This means you can use, say,
1022 $ah or $ax to refer, respectively, to the byte register AH and
1023 16-bit word register AX that are actually portions of the 32-bit
1024 register EAX or 64-bit register RAX.
1026 * The `commands' command now accepts a range of breakpoints to modify.
1027 A plain `commands' following a command that creates multiple
1028 breakpoints affects all the breakpoints set by that command. This
1029 applies to breakpoints set by `rbreak', and also applies when a
1030 single `break' command creates multiple breakpoints (e.g.,
1031 breakpoints on overloaded c++ functions).
1033 * The `rbreak' command now accepts a filename specification as part of
1034 its argument, limiting the functions selected by the regex to those
1035 in the specified file.
1037 * Support for remote debugging Windows and SymbianOS shared libraries
1038 from Unix hosts has been improved. Non Windows GDB builds now can
1039 understand target reported file names that follow MS-DOS based file
1040 system semantics, such as file names that include drive letters and
1041 use the backslash character as directory separator. This makes it
1042 possible to transparently use the "set sysroot" and "set
1043 solib-search-path" on Unix hosts to point as host copies of the
1044 target's shared libraries. See the new command "set
1045 target-file-system-kind" described below, and the "Commands to
1046 specify files" section in the user manual for more information.
1050 eval template, expressions...
1051 Convert the values of one or more expressions under the control
1052 of the string template to a command line, and call it.
1054 set target-file-system-kind unix|dos-based|auto
1055 show target-file-system-kind
1056 Set or show the assumed file system kind for target reported file
1059 save breakpoints <filename>
1060 Save all current breakpoint definitions to a file suitable for use
1061 in a later debugging session. To read the saved breakpoint
1062 definitions, use the `source' command.
1064 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1067 info static-tracepoint-markers
1068 Display information about static tracepoint markers in the target.
1070 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1071 Define a static tracepoint by probing a marker at the given
1072 function, line, address, or marker ID.
1076 Enable and disable observer mode.
1078 set may-write-registers on|off
1079 set may-write-memory on|off
1080 set may-insert-breakpoints on|off
1081 set may-insert-tracepoints on|off
1082 set may-insert-fast-tracepoints on|off
1083 set may-interrupt on|off
1084 Set individual permissions for GDB effects on the target. Note that
1085 some of these settings can have undesirable or surprising
1086 consequences, particularly when changed in the middle of a session.
1087 For instance, disabling the writing of memory can prevent
1088 breakpoints from being inserted, cause single-stepping to fail, or
1089 even crash your program, if you disable after breakpoints have been
1090 inserted. However, GDB should not crash.
1092 set record memory-query on|off
1093 show record memory-query
1094 Control whether to stop the inferior if memory changes caused
1095 by an instruction cannot be recorded.
1100 The disassemble command now supports "start,+length" form of two arguments.
1104 ** GDB now provides a new directory location, called the python directory,
1105 where Python scripts written for GDB can be installed. The location
1106 of that directory is <data-directory>/python, where <data-directory>
1107 is the GDB data directory. For more details, see section `Scripting
1108 GDB using Python' in the manual.
1110 ** The GDB Python API now has access to breakpoints, symbols, symbol
1111 tables, program spaces, inferiors, threads and frame's code blocks.
1112 Additionally, GDB Parameters can now be created from the API, and
1113 manipulated via set/show in the CLI.
1115 ** New functions gdb.target_charset, gdb.target_wide_charset,
1116 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1118 ** New exception gdb.GdbError.
1120 ** Pretty-printers are now also looked up in the current program space.
1122 ** Pretty-printers can now be individually enabled and disabled.
1124 ** GDB now looks for names of Python scripts to auto-load in a
1125 special section named `.debug_gdb_scripts', in addition to looking
1126 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1128 * Tracepoint actions were unified with breakpoint commands. In particular,
1129 there are no longer differences in "info break" output for breakpoints and
1130 tracepoints and the "commands" command can be used for both tracepoints and
1131 regular breakpoints.
1135 ARM Symbian arm*-*-symbianelf*
1137 * D language support.
1138 GDB now supports debugging programs written in the D programming
1141 * GDB now supports the extended ptrace interface for PowerPC which is
1142 available since Linux kernel version 2.6.34. This automatically enables
1143 any hardware breakpoints and additional hardware watchpoints available in
1144 the processor. The old ptrace interface exposes just one hardware
1145 watchpoint and no hardware breakpoints.
1147 * GDB is now able to use the Data Value Compare (DVC) register available on
1148 embedded PowerPC processors to implement in hardware simple watchpoint
1149 conditions of the form:
1151 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1153 This works in native GDB running on Linux kernels with the extended ptrace
1154 interface mentioned above.
1156 *** Changes in GDB 7.1
1160 ** Namespace Support
1162 GDB now supports importing of namespaces in C++. This enables the
1163 user to inspect variables from imported namespaces. Support for
1164 namepace aliasing has also been added. So, if a namespace is
1165 aliased in the current scope (e.g. namepace C=A; ) the user can
1166 print variables using the alias (e.g. (gdb) print C::x).
1170 All known bugs relating to the printing of virtual base class were
1171 fixed. It is now possible to call overloaded static methods using a
1176 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1177 and reinterpret_cast<> are now handled by the C++ expression parser.
1181 Xilinx MicroBlaze microblaze-*-*
1186 Xilinx MicroBlaze microblaze
1189 * Multi-program debugging.
1191 GDB now has support for multi-program (a.k.a. multi-executable or
1192 multi-exec) debugging. This allows for debugging multiple inferiors
1193 simultaneously each running a different program under the same GDB
1194 session. See "Debugging Multiple Inferiors and Programs" in the
1195 manual for more information. This implied some user visible changes
1196 in the multi-inferior support. For example, "info inferiors" now
1197 lists inferiors that are not running yet or that have exited
1198 already. See also "New commands" and "New options" below.
1200 * New tracing features
1202 GDB's tracepoint facility now includes several new features:
1204 ** Trace state variables
1206 GDB tracepoints now include support for trace state variables, which
1207 are variables managed by the target agent during a tracing
1208 experiment. They are useful for tracepoints that trigger each
1209 other, so for instance one tracepoint can count hits in a variable,
1210 and then a second tracepoint has a condition that is true when the
1211 count reaches a particular value. Trace state variables share the
1212 $-syntax of GDB convenience variables, and can appear in both
1213 tracepoint actions and condition expressions. Use the "tvariable"
1214 command to create, and "info tvariables" to view; see "Trace State
1215 Variables" in the manual for more detail.
1219 GDB now includes an option for defining fast tracepoints, which
1220 targets may implement more efficiently, such as by installing a jump
1221 into the target agent rather than a trap instruction. The resulting
1222 speedup can be by two orders of magnitude or more, although the
1223 tradeoff is that some program locations on some target architectures
1224 might not allow fast tracepoint installation, for instance if the
1225 instruction to be replaced is shorter than the jump. To request a
1226 fast tracepoint, use the "ftrace" command, with syntax identical to
1227 the regular trace command.
1229 ** Disconnected tracing
1231 It is now possible to detach GDB from the target while it is running
1232 a trace experiment, then reconnect later to see how the experiment
1233 is going. In addition, a new variable disconnected-tracing lets you
1234 tell the target agent whether to continue running a trace if the
1235 connection is lost unexpectedly.
1239 GDB now has the ability to save the trace buffer into a file, and
1240 then use that file as a target, similarly to you can do with
1241 corefiles. You can select trace frames, print data that was
1242 collected in them, and use tstatus to display the state of the
1243 tracing run at the moment that it was saved. To create a trace
1244 file, use "tsave <filename>", and to use it, do "target tfile
1247 ** Circular trace buffer
1249 You can ask the target agent to handle the trace buffer as a
1250 circular buffer, discarding the oldest trace frames to make room for
1251 newer ones, by setting circular-trace-buffer to on. This feature may
1252 not be available for all target agents.
1257 The disassemble command, when invoked with two arguments, now requires
1258 the arguments to be comma-separated.
1261 The info variables command now displays variable definitions. Files
1262 which only declare a variable are not shown.
1265 The source command is now capable of sourcing Python scripts.
1266 This feature is dependent on the debugger being build with Python
1269 Related to this enhancement is also the introduction of a new command
1270 "set script-extension" (see below).
1272 * New commands (for set/show, see "New options" below)
1274 record save [<FILENAME>]
1275 Save a file (in core file format) containing the process record
1276 execution log for replay debugging at a later time.
1278 record restore <FILENAME>
1279 Restore the process record execution log that was saved at an
1280 earlier time, for replay debugging.
1282 add-inferior [-copies <N>] [-exec <FILENAME>]
1285 clone-inferior [-copies <N>] [ID]
1286 Make a new inferior ready to execute the same program another
1287 inferior has loaded.
1292 maint info program-spaces
1293 List the program spaces loaded into GDB.
1295 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1296 show remote interrupt-sequence
1297 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1298 as the sequence to the remote target in order to interrupt the execution.
1299 Ctrl-C is a default. Some system prefers BREAK which is high level of
1300 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1301 Magic SysRq g. It is BREAK signal and character 'g'.
1303 set remote interrupt-on-connect [on | off]
1304 show remote interrupt-on-connect
1305 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1306 remote target when gdb connects to it. This is needed when you debug
1309 set remotebreak [on | off]
1311 Deprecated. Use "set/show remote interrupt-sequence" instead.
1313 tvariable $NAME [ = EXP ]
1314 Create or modify a trace state variable.
1317 List trace state variables and their values.
1319 delete tvariable $NAME ...
1320 Delete one or more trace state variables.
1323 Evaluate the given expressions without collecting anything into the
1324 trace buffer. (Valid in tracepoint actions only.)
1326 ftrace FN / FILE:LINE / *ADDR
1327 Define a fast tracepoint at the given function, line, or address.
1329 * New expression syntax
1331 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1332 GDB now parses 0b101010 identically with 42.
1336 set follow-exec-mode new|same
1337 show follow-exec-mode
1338 Control whether GDB reuses the same inferior across an exec call or
1339 creates a new one. This is useful to be able to restart the old
1340 executable after the inferior having done an exec call.
1342 set default-collect EXPR, ...
1343 show default-collect
1344 Define a list of expressions to be collected at each tracepoint.
1345 This is a useful way to ensure essential items are not overlooked,
1346 such as registers or a critical global variable.
1348 set disconnected-tracing
1349 show disconnected-tracing
1350 If set to 1, the target is instructed to continue tracing if it
1351 loses its connection to GDB. If 0, the target is to stop tracing
1354 set circular-trace-buffer
1355 show circular-trace-buffer
1356 If set to on, the target is instructed to use a circular trace buffer
1357 and discard the oldest trace frames instead of stopping the trace due
1358 to a full trace buffer. If set to off, the trace stops when the buffer
1359 fills up. Some targets may not support this.
1361 set script-extension off|soft|strict
1362 show script-extension
1363 If set to "off", the debugger does not perform any script language
1364 recognition, and all sourced files are assumed to be GDB scripts.
1365 If set to "soft" (the default), files are sourced according to
1366 filename extension, falling back to GDB scripts if the first
1368 If set to "strict", files are sourced according to filename extension.
1370 set ada trust-PAD-over-XVS on|off
1371 show ada trust-PAD-over-XVS
1372 If off, activate a workaround against a bug in the debugging information
1373 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1374 the GCC sources for more information about the GNAT encoding and
1375 PAD types in particular). It is always safe to set this option to
1376 off, but this introduces a slight performance penalty. The default
1379 * Python API Improvements
1381 ** GDB provides the new class gdb.LazyString. This is useful in
1382 some pretty-printing cases. The new method gdb.Value.lazy_string
1383 provides a simple way to create objects of this type.
1385 ** The fields returned by gdb.Type.fields now have an
1386 `is_base_class' attribute.
1388 ** The new method gdb.Type.range returns the range of an array type.
1390 ** The new method gdb.parse_and_eval can be used to parse and
1391 evaluate an expression.
1393 * New remote packets
1396 Define a trace state variable.
1399 Get the current value of a trace state variable.
1402 Set desired tracing behavior upon disconnection.
1405 Set the trace buffer to be linear or circular.
1408 Get data about the tracepoints currently in use.
1412 Process record now works correctly with hardware watchpoints.
1414 Multiple bug fixes have been made to the mips-irix port, making it
1415 much more reliable. In particular:
1416 - Debugging threaded applications is now possible again. Previously,
1417 GDB would hang while starting the program, or while waiting for
1418 the program to stop at a breakpoint.
1419 - Attaching to a running process no longer hangs.
1420 - An error occurring while loading a core file has been fixed.
1421 - Changing the value of the PC register now works again. This fixes
1422 problems observed when using the "jump" command, or when calling
1423 a function from GDB, or even when assigning a new value to $pc.
1424 - With the "finish" and "return" commands, the return value for functions
1425 returning a small array is now correctly printed.
1426 - It is now possible to break on shared library code which gets executed
1427 during a shared library init phase (code executed while executing
1428 their .init section). Previously, the breakpoint would have no effect.
1429 - GDB is now able to backtrace through the signal handler for
1430 non-threaded programs.
1432 PIE (Position Independent Executable) programs debugging is now supported.
1433 This includes debugging execution of PIC (Position Independent Code) shared
1434 libraries although for that, it should be possible to run such libraries as an
1437 *** Changes in GDB 7.0
1439 * GDB now has an interface for JIT compilation. Applications that
1440 dynamically generate code can create symbol files in memory and register
1441 them with GDB. For users, the feature should work transparently, and
1442 for JIT developers, the interface is documented in the GDB manual in the
1443 "JIT Compilation Interface" chapter.
1445 * Tracepoints may now be conditional. The syntax is as for
1446 breakpoints; either an "if" clause appended to the "trace" command,
1447 or the "condition" command is available. GDB sends the condition to
1448 the target for evaluation using the same bytecode format as is used
1449 for tracepoint actions.
1451 * The disassemble command now supports: an optional /r modifier, print the
1452 raw instructions in hex as well as in symbolic form, and an optional /m
1453 modifier to print mixed source+assembly.
1455 * Process record and replay
1457 In a architecture environment that supports ``process record and
1458 replay'', ``process record and replay'' target can record a log of
1459 the process execution, and replay it with both forward and reverse
1462 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1463 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1464 set execution-direction {forward|reverse}, for targets that support
1467 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1468 feature is available with a native GDB running on kernel version
1471 * GDB now has support for multi-byte and wide character sets on the
1472 target. Strings whose character type is wchar_t, char16_t, or
1473 char32_t are now correctly printed. GDB supports wide- and unicode-
1474 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1475 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1476 `printf'. This feature requires iconv to work properly; if your
1477 system does not have a working iconv, GDB can use GNU libiconv. See
1478 the installation instructions for more information.
1480 * GDB now supports automatic retrieval of shared library files from
1481 remote targets. To use this feature, specify a system root that begins
1482 with the `remote:' prefix, either via the `set sysroot' command or via
1483 the `--with-sysroot' configure-time option.
1485 * "info sharedlibrary" now takes an optional regex of libraries to show,
1486 and it now reports if a shared library has no debugging information.
1488 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1489 now complete on file names.
1491 * When completing in expressions, gdb will attempt to limit
1492 completions to allowable structure or union fields, where appropriate.
1493 For instance, consider:
1495 # struct example { int f1; double f2; };
1496 # struct example variable;
1499 If the user types TAB at the end of this command line, the available
1500 completions will be "f1" and "f2".
1502 * Inlined functions are now supported. They show up in backtraces, and
1503 the "step", "next", and "finish" commands handle them automatically.
1505 * GDB now supports the token-splicing (##) and stringification (#)
1506 operators when expanding macros. It also supports variable-arity
1509 * GDB now supports inspecting extra signal information, exported by
1510 the new $_siginfo convenience variable. The feature is currently
1511 implemented on linux ARM, i386 and amd64.
1513 * GDB can now display the VFP floating point registers and NEON vector
1514 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1515 can provide these registers (requires Linux 2.6.30 or later). Remote
1516 and simulator targets may also provide them.
1518 * New remote packets
1521 Search memory for a sequence of bytes.
1524 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1525 operation over reliable transport links. Use of this packet is
1526 controlled by the `set remote noack-packet' command.
1529 Kill the process with the specified process ID. Use this in preference
1530 to `k' when multiprocess protocol extensions are supported.
1533 Obtains additional operating system information
1537 Read or write additional signal information.
1539 * Removed remote protocol undocumented extension
1541 An undocumented extension to the remote protocol's `S' stop reply
1542 packet that permited the stub to pass a process id was removed.
1543 Remote servers should use the `T' stop reply packet instead.
1545 * GDB now supports multiple function calling conventions according to the
1546 DWARF-2 DW_AT_calling_convention function attribute.
1548 * The SH target utilizes the aforementioned change to distinguish between gcc
1549 and Renesas calling convention. It also adds the new CLI commands
1550 `set/show sh calling-convention'.
1552 * GDB can now read compressed debug sections, as produced by GNU gold
1553 with the --compress-debug-sections=zlib flag.
1555 * 64-bit core files are now supported on AIX.
1557 * Thread switching is now supported on Tru64.
1559 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1560 which will be allocated using malloc later in program execution.
1562 * The qXfer:libraries:read remote procotol packet now allows passing a
1563 list of section offsets.
1565 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1566 conditions handling signals delivered during attach or thread creation
1567 have also been fixed.
1569 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1570 From the user's standpoint, all unqualified instances of True and False
1571 are treated as the standard definitions, regardless of context.
1573 * GDB now parses C++ symbol and type names more flexibly. For
1576 template<typename T> class C { };
1579 GDB will now correctly handle all of:
1581 ptype C<char const *>
1582 ptype C<char const*>
1583 ptype C<const char *>
1584 ptype C<const char*>
1586 * New features in the GDB remote stub, gdbserver
1588 - The "--wrapper" command-line argument tells gdbserver to use a
1589 wrapper program to launch programs for debugging.
1591 - On PowerPC and S/390 targets, it is now possible to use a single
1592 gdbserver executable to debug both 32-bit and 64-bit programs.
1593 (This requires gdbserver itself to be built as a 64-bit executable.)
1595 - gdbserver uses the new noack protocol mode for TCP connections to
1596 reduce communications latency, if also supported and enabled in GDB.
1598 - Support for the sparc64-linux-gnu target is now included in
1601 - The amd64-linux build of gdbserver now supports debugging both
1602 32-bit and 64-bit programs.
1604 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1605 now support hardware watchpoints, and will use them automatically
1610 GDB now has support for scripting using Python. Whether this is
1611 available is determined at configure time.
1613 New GDB commands can now be written in Python.
1615 * Ada tasking support
1617 Ada tasks can now be inspected in GDB. The following commands have
1621 Print the list of Ada tasks.
1623 Print detailed information about task number N.
1625 Print the task number of the current task.
1627 Switch the context of debugging to task number N.
1629 * Support for user-defined prefixed commands. The "define" command can
1630 add new commands to existing prefixes, e.g. "target".
1632 * Multi-inferior, multi-process debugging.
1634 GDB now has generalized support for multi-inferior debugging. See
1635 "Debugging Multiple Inferiors" in the manual for more information.
1636 Although availability still depends on target support, the command
1637 set is more uniform now. The GNU/Linux specific multi-forks support
1638 has been migrated to this new framework. This implied some user
1639 visible changes; see "New commands" and also "Removed commands"
1642 * Target descriptions can now describe the target OS ABI. See the
1643 "Target Description Format" section in the user manual for more
1646 * Target descriptions can now describe "compatible" architectures
1647 to indicate that the target can execute applications for a different
1648 architecture in addition to those for the main target architecture.
1649 See the "Target Description Format" section in the user manual for
1652 * Multi-architecture debugging.
1654 GDB now includes general supports for debugging applications on
1655 hybrid systems that use more than one single processor architecture
1656 at the same time. Each such hybrid architecture still requires
1657 specific support to be added. The only hybrid architecture supported
1658 in this version of GDB is the Cell Broadband Engine.
1660 * GDB now supports integrated debugging of Cell/B.E. applications that
1661 use both the PPU and SPU architectures. To enable support for hybrid
1662 Cell/B.E. debugging, you need to configure GDB to support both the
1663 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1664 --enable-targets configure option.
1666 * Non-stop mode debugging.
1668 For some targets, GDB now supports an optional mode of operation in
1669 which you can examine stopped threads while other threads continue
1670 to execute freely. This is referred to as non-stop mode, with the
1671 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1672 section in the user manual for more information.
1674 To be able to support remote non-stop debugging, a remote stub needs
1675 to implement the non-stop mode remote protocol extensions, as
1676 described in the "Remote Non-Stop" section of the user manual. The
1677 GDB remote stub, gdbserver, has been adjusted to support these
1678 extensions on linux targets.
1680 * New commands (for set/show, see "New options" below)
1682 catch syscall [NAME(S) | NUMBER(S)]
1683 Catch system calls. Arguments, which should be names of system
1684 calls or their numbers, mean catch only those syscalls. Without
1685 arguments, every syscall will be caught. When the inferior issues
1686 any of the specified syscalls, GDB will stop and announce the system
1687 call, both when it is called and when its call returns. This
1688 feature is currently available with a native GDB running on the
1689 Linux Kernel, under the following architectures: x86, x86_64,
1690 PowerPC and PowerPC64.
1692 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1694 Search memory for a sequence of bytes.
1696 maint set python print-stack
1697 maint show python print-stack
1698 Show a stack trace when an error is encountered in a Python script.
1701 Invoke CODE by passing it to the Python interpreter.
1706 These allow macros to be defined, undefined, and listed
1710 Show operating system information about processes.
1713 List the inferiors currently under GDB's control.
1716 Switch focus to inferior number NUM.
1719 Detach from inferior number NUM.
1722 Kill inferior number NUM.
1726 set spu stop-on-load
1727 show spu stop-on-load
1728 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1730 set spu auto-flush-cache
1731 show spu auto-flush-cache
1732 Control whether to automatically flush the software-managed cache
1733 during Cell/B.E. debugging.
1735 set sh calling-convention
1736 show sh calling-convention
1737 Control the calling convention used when calling SH target functions.
1740 show debug timestamp
1741 Control display of timestamps with GDB debugging output.
1743 set disassemble-next-line
1744 show disassemble-next-line
1745 Control display of disassembled source lines or instructions when
1748 set remote noack-packet
1749 show remote noack-packet
1750 Set/show the use of remote protocol QStartNoAckMode packet. See above
1751 under "New remote packets."
1753 set remote query-attached-packet
1754 show remote query-attached-packet
1755 Control use of remote protocol `qAttached' (query-attached) packet.
1757 set remote read-siginfo-object
1758 show remote read-siginfo-object
1759 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1762 set remote write-siginfo-object
1763 show remote write-siginfo-object
1764 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1767 set remote reverse-continue
1768 show remote reverse-continue
1769 Control use of remote protocol 'bc' (reverse-continue) packet.
1771 set remote reverse-step
1772 show remote reverse-step
1773 Control use of remote protocol 'bs' (reverse-step) packet.
1775 set displaced-stepping
1776 show displaced-stepping
1777 Control displaced stepping mode. Displaced stepping is a way to
1778 single-step over breakpoints without removing them from the debuggee.
1779 Also known as "out-of-line single-stepping".
1782 show debug displaced
1783 Control display of debugging info for displaced stepping.
1785 maint set internal-error
1786 maint show internal-error
1787 Control what GDB does when an internal error is detected.
1789 maint set internal-warning
1790 maint show internal-warning
1791 Control what GDB does when an internal warning is detected.
1796 Use a wrapper program to launch programs for debugging.
1798 set multiple-symbols (all|ask|cancel)
1799 show multiple-symbols
1800 The value of this variable can be changed to adjust the debugger behavior
1801 when an expression or a breakpoint location contains an ambiguous symbol
1802 name (an overloaded function name, for instance).
1804 set breakpoint always-inserted
1805 show breakpoint always-inserted
1806 Keep breakpoints always inserted in the target, as opposed to inserting
1807 them when resuming the target, and removing them when the target stops.
1808 This option can improve debugger performance on slow remote targets.
1810 set arm fallback-mode (arm|thumb|auto)
1811 show arm fallback-mode
1812 set arm force-mode (arm|thumb|auto)
1814 These commands control how ARM GDB determines whether instructions
1815 are ARM or Thumb. The default for both settings is auto, which uses
1816 the current CPSR value for instructions without symbols; previous
1817 versions of GDB behaved as if "set arm fallback-mode arm".
1819 set disable-randomization
1820 show disable-randomization
1821 Standalone programs run with the virtual address space randomization enabled
1822 by default on some platforms. This option keeps the addresses stable across
1823 multiple debugging sessions.
1827 Control whether other threads are stopped or not when some thread hits
1832 Requests that asynchronous execution is enabled in the target, if available.
1833 In this case, it's possible to resume target in the background, and interact
1834 with GDB while the target is running. "show target-async" displays the
1835 current state of asynchronous execution of the target.
1837 set target-wide-charset
1838 show target-wide-charset
1839 The target-wide-charset is the name of the character set that GDB
1840 uses when printing characters whose type is wchar_t.
1842 set tcp auto-retry (on|off)
1844 set tcp connect-timeout
1845 show tcp connect-timeout
1846 These commands allow GDB to retry failed TCP connections to a remote stub
1847 with a specified timeout period; this is useful if the stub is launched
1848 in parallel with GDB but may not be ready to accept connections immediately.
1850 set libthread-db-search-path
1851 show libthread-db-search-path
1852 Control list of directories which GDB will search for appropriate
1855 set schedule-multiple (on|off)
1856 show schedule-multiple
1857 Allow GDB to resume all threads of all processes or only threads of
1858 the current process.
1862 Use more aggressive caching for accesses to the stack. This improves
1863 performance of remote debugging (particularly backtraces) without
1864 affecting correctness.
1866 set interactive-mode (on|off|auto)
1867 show interactive-mode
1868 Control whether GDB runs in interactive mode (on) or not (off).
1869 When in interactive mode, GDB waits for the user to answer all
1870 queries. Otherwise, GDB does not wait and assumes the default
1871 answer. When set to auto (the default), GDB determines which
1872 mode to use based on the stdin settings.
1877 For program forks, this is replaced by the new more generic `info
1878 inferiors' command. To list checkpoints, you can still use the
1879 `info checkpoints' command, which was an alias for the `info forks'
1883 Replaced by the new `inferior' command. To switch between
1884 checkpoints, you can still use the `restart' command, which was an
1885 alias for the `fork' command.
1888 This is removed, since some targets don't have a notion of
1889 processes. To switch between processes, you can still use the
1890 `inferior' command using GDB's own inferior number.
1893 For program forks, this is replaced by the new more generic `kill
1894 inferior' command. To delete a checkpoint, you can still use the
1895 `delete checkpoint' command, which was an alias for the `delete
1899 For program forks, this is replaced by the new more generic `detach
1900 inferior' command. To detach a checkpoint, you can still use the
1901 `detach checkpoint' command, which was an alias for the `detach
1904 * New native configurations
1906 x86/x86_64 Darwin i[34567]86-*-darwin*
1908 x86_64 MinGW x86_64-*-mingw*
1912 Lattice Mico32 lm32-*
1913 x86 DICOS i[34567]86-*-dicos*
1914 x86_64 DICOS x86_64-*-dicos*
1917 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1918 (mingw32ce) debugging.
1924 These commands were actually not implemented on any target.
1926 *** Changes in GDB 6.8
1928 * New native configurations
1930 NetBSD/hppa hppa*-*netbsd*
1931 Xtensa GNU/Linux xtensa*-*-linux*
1935 NetBSD/hppa hppa*-*-netbsd*
1936 Xtensa GNU/Lunux xtensa*-*-linux*
1938 * Change in command line behavior -- corefiles vs. process ids.
1940 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1941 attaching to process NUMBER fails, GDB no longer attempts to open a
1942 core file named NUMBER. Attaching to a program using the -c option
1943 is no longer supported. Instead, use the '-p' or '--pid' options.
1945 * GDB can now be built as a native debugger for debugging Windows x86
1946 (mingw32) Portable Executable (PE) programs.
1948 * Pending breakpoints no longer change their number when their address
1951 * GDB now supports breakpoints with multiple locations,
1952 including breakpoints on C++ constructors, inside C++ templates,
1953 and in inlined functions.
1955 * GDB's ability to debug optimized code has been improved. GDB more
1956 accurately identifies function bodies and lexical blocks that occupy
1957 more than one contiguous range of addresses.
1959 * Target descriptions can now describe registers for PowerPC.
1961 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1962 registers on PowerPC targets.
1964 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1965 targets even when the libthread_db library is not available.
1967 * The GDB remote stub, gdbserver, now supports the new file transfer
1968 commands (remote put, remote get, and remote delete).
1970 * The GDB remote stub, gdbserver, now supports run and attach in
1971 extended-remote mode.
1973 * hppa*64*-*-hpux11* target broken
1974 The debugger is unable to start a program and fails with the following
1975 error: "Error trying to get information about dynamic linker".
1976 The gdb-6.7 release is also affected.
1978 * GDB now supports the --enable-targets= configure option to allow
1979 building a single GDB executable that supports multiple remote
1980 target architectures.
1982 * GDB now supports debugging C and C++ programs which use the
1983 Decimal Floating Point extension. In addition, the PowerPC target
1984 now has a set of pseudo-registers to inspect decimal float values
1985 stored in two consecutive float registers.
1987 * The -break-insert MI command can optionally create pending
1990 * Improved support for debugging Ada
1991 Many improvements to the Ada language support have been made. These
1993 - Better support for Ada2005 interface types
1994 - Improved handling of arrays and slices in general
1995 - Better support for Taft-amendment types
1996 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1998 - Improved command completion in Ada
2001 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2006 set print frame-arguments (all|scalars|none)
2007 show print frame-arguments
2008 The value of this variable can be changed to control which argument
2009 values should be printed by the debugger when displaying a frame.
2014 Transfer files to and from a remote target, and delete remote files.
2021 Transfer files to and from a remote target, and delete remote files.
2023 * New remote packets
2030 Open, close, read, write, and delete files on the remote system.
2033 Attach to an existing process on the remote system, in extended-remote
2037 Run a new process on the remote system, in extended-remote mode.
2039 *** Changes in GDB 6.7
2041 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2042 bfd, libiberty and opcodes, as revealed by static analysis donated by
2043 Coverity, Inc. (http://scan.coverity.com).
2045 * When looking up multiply-defined global symbols, GDB will now prefer the
2046 symbol definition in the current shared library if it was built using the
2047 -Bsymbolic linker option.
2049 * When the Text User Interface (TUI) is not configured, GDB will now
2050 recognize the -tui command-line option and print a message that the TUI
2053 * The GDB remote stub, gdbserver, now has lower overhead for high
2054 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2056 * GDB for MIPS targets now autodetects whether a remote target provides
2057 32-bit or 64-bit register values.
2059 * Support for C++ member pointers has been improved.
2061 * GDB now understands XML target descriptions, which specify the
2062 target's overall architecture. GDB can read a description from
2063 a local file or over the remote serial protocol.
2065 * Vectors of single-byte data use a new integer type which is not
2066 automatically displayed as character or string data.
2068 * The /s format now works with the print command. It displays
2069 arrays of single-byte integers and pointers to single-byte integers
2072 * Target descriptions can now describe target-specific registers,
2073 for architectures which have implemented the support (currently
2074 only ARM, M68K, and MIPS).
2076 * GDB and the GDB remote stub, gdbserver, now support the XScale
2079 * The GDB remote stub, gdbserver, has been updated to support
2080 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2081 has been rewritten to use the standard GDB remote protocol.
2083 * GDB can now step into C++ functions which are called through thunks.
2085 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2087 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2088 layout. It also supports a TextSeg= and DataSeg= response when only
2089 segment base addresses (rather than offsets) are available.
2091 * The /i format now outputs any trailing branch delay slot instructions
2092 immediately following the last instruction within the count specified.
2094 * The GDB remote protocol "T" stop reply packet now supports a
2095 "library" response. Combined with the new "qXfer:libraries:read"
2096 packet, this response allows GDB to debug shared libraries on targets
2097 where the operating system manages the list of loaded libraries (e.g.
2098 Windows and SymbianOS).
2100 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2101 (DLLs) on Windows and Windows CE targets.
2103 * GDB now supports a faster verification that a .debug file matches its binary
2104 according to its build-id signature, if the signature is present.
2110 Enable or disable hardware flow control (RTS/CTS) on the serial port
2111 when debugging using remote targets.
2113 set mem inaccessible-by-default
2114 show mem inaccessible-by-default
2115 If the target supplies a memory map, for instance via the remote
2116 protocol's "qXfer:memory-map:read" packet, setting this variable
2117 prevents GDB from accessing memory outside the memory map. This
2118 is useful for targets with memory mapped registers or which react
2119 badly to accesses of unmapped address space.
2121 set breakpoint auto-hw
2122 show breakpoint auto-hw
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 lets GDB use hardware breakpoints automatically for memory regions
2126 where it can not use software breakpoints. This covers both the
2127 "break" command and internal breakpoints used for other commands
2128 including "next" and "finish".
2131 catch exception unhandled
2132 Stop the program execution when Ada exceptions are raised.
2135 Stop the program execution when an Ada assertion failed.
2139 Set an alternate system root for target files. This is a more
2140 general version of "set solib-absolute-prefix", which is now
2141 an alias to "set sysroot".
2144 Provide extended SPU facility status information. This set of
2145 commands is available only when debugging the Cell/B.E. SPU
2148 * New native configurations
2150 OpenBSD/sh sh*-*openbsd*
2153 unset tdesc filename
2155 Use the specified local file as an XML target description, and do
2156 not query the target for its built-in description.
2160 OpenBSD/sh sh*-*-openbsd*
2161 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2162 Toshiba Media Processor mep-elf
2164 * New remote packets
2167 Ignore the specified signals; pass them directly to the debugged program
2168 without stopping other threads or reporting them to GDB.
2170 qXfer:features:read:
2171 Read an XML target description from the target, which describes its
2176 Read or write contents of an spufs file on the target system. These
2177 packets are available only on the Cell/B.E. SPU architecture.
2179 qXfer:libraries:read:
2180 Report the loaded shared libraries. Combined with new "T" packet
2181 response, this packet allows GDB to debug shared libraries on
2182 targets where the operating system manages the list of loaded
2183 libraries (e.g. Windows and SymbianOS).
2187 Support for these obsolete configurations has been removed.
2195 i[34567]86-*-lynxos*
2196 i[34567]86-*-netware*
2197 i[34567]86-*-sco3.2v5*
2198 i[34567]86-*-sco3.2v4*
2200 i[34567]86-*-sysv4.2*
2203 i[34567]86-*-unixware2*
2204 i[34567]86-*-unixware*
2213 * Other removed features
2220 Various m68k-only ROM monitors.
2227 Various Renesas ROM monitors and debugging interfaces for SH and
2232 Support for a Macraigor serial interface to on-chip debugging.
2233 GDB does not directly support the newer parallel or USB
2238 A debug information format. The predecessor to DWARF 2 and
2239 DWARF 3, which are still supported.
2241 Support for the HP aCC compiler on HP-UX/PA-RISC
2243 SOM-encapsulated symbolic debugging information, automatic
2244 invocation of pxdb, and the aCC custom C++ ABI. This does not
2245 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2246 with aCC can still be debugged on an assembly level.
2248 MIPS ".pdr" sections
2250 A MIPS-specific format used to describe stack frame layout
2251 in debugging information.
2255 GDB could work with an older version of Guile to debug
2256 the interpreter and Scheme programs running in it.
2258 set mips stack-arg-size
2259 set mips saved-gpreg-size
2261 Use "set mips abi" to control parameter passing for MIPS.
2263 *** Changes in GDB 6.6
2268 Cell Broadband Engine SPU spu-elf
2270 * GDB can now be configured as a cross-debugger targeting native Windows
2271 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2272 running on a Windows system over TCP/IP to debug Windows programs.
2274 * The GDB remote stub, gdbserver, has been updated to support Windows and
2275 Cygwin debugging. Both single-threaded and multi-threaded programs are
2278 * The "set trust-readonly-sections" command works again. This command was
2279 broken in GDB 6.3, 6.4, and 6.5.
2281 * The "load" command now supports writing to flash memory, if the remote
2282 stub provides the required support.
2284 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2285 longer requires symbolic debug information (e.g. DWARF-2).
2290 unset substitute-path
2291 show substitute-path
2292 Manage a list of substitution rules that GDB uses to rewrite the name
2293 of the directories where the sources are located. This can be useful
2294 for instance when the sources were moved to a different location
2295 between compilation and debugging.
2299 Print each CLI command as it is executed. Each command is prefixed with
2300 a number of `+' symbols representing the nesting depth.
2301 The source command now has a `-v' option to enable the same feature.
2305 The ARM Demon monitor support (RDP protocol, "target rdp").
2307 Kernel Object Display, an embedded debugging feature which only worked with
2308 an obsolete version of Cisco IOS.
2310 The 'set download-write-size' and 'show download-write-size' commands.
2312 * New remote packets
2315 Tell a stub about GDB client features, and request remote target features.
2316 The first feature implemented is PacketSize, which allows the target to
2317 specify the size of packets it can handle - to minimize the number of
2318 packets required and improve performance when connected to a remote
2322 Fetch an OS auxilliary vector from the remote stub. This packet is a
2323 more efficient replacement for qPart:auxv:read.
2325 qXfer:memory-map:read:
2326 Fetch a memory map from the remote stub, including information about
2327 RAM, ROM, and flash memory devices.
2332 Erase and program a flash memory device.
2334 * Removed remote packets
2337 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2338 used it, and only gdbserver implemented it.
2340 *** Changes in GDB 6.5
2344 Renesas M32C/M16C m32c-elf
2346 Morpho Technologies ms1 ms1-elf
2350 init-if-undefined Initialize a convenience variable, but
2351 only if it doesn't already have a value.
2353 The following commands are presently only implemented for native GNU/Linux:
2355 checkpoint Save a snapshot of the program state.
2357 restart <n> Return the program state to a
2358 previously saved state.
2360 info checkpoints List currently saved checkpoints.
2362 delete-checkpoint <n> Delete a previously saved checkpoint.
2364 set|show detach-on-fork Tell gdb whether to detach from a newly
2365 forked process, or to keep debugging it.
2367 info forks List forks of the user program that
2368 are available to be debugged.
2370 fork <n> Switch to debugging one of several
2371 forks of the user program that are
2372 available to be debugged.
2374 delete-fork <n> Delete a fork from the list of forks
2375 that are available to be debugged (and
2376 kill the forked process).
2378 detach-fork <n> Delete a fork from the list of forks
2379 that are available to be debugged (and
2380 allow the process to continue).
2384 Morpho Technologies ms2 ms1-elf
2386 * Improved Windows host support
2388 GDB now builds as a cross debugger hosted on i686-mingw32, including
2389 native console support, and remote communications using either
2390 network sockets or serial ports.
2392 * Improved Modula-2 language support
2394 GDB can now print most types in the Modula-2 syntax. This includes:
2395 basic types, set types, record types, enumerated types, range types,
2396 pointer types and ARRAY types. Procedure var parameters are correctly
2397 printed and hexadecimal addresses and character constants are also
2398 written in the Modula-2 syntax. Best results can be obtained by using
2399 GNU Modula-2 together with the -gdwarf-2 command line option.
2403 The ARM rdi-share module.
2405 The Netware NLM debug server.
2407 *** Changes in GDB 6.4
2409 * New native configurations
2411 OpenBSD/arm arm*-*-openbsd*
2412 OpenBSD/mips64 mips64-*-openbsd*
2416 Morpho Technologies ms1 ms1-elf
2418 * New command line options
2420 --batch-silent As for --batch, but totally silent.
2421 --return-child-result The debugger will exist with the same value
2422 the child (debugged) program exited with.
2423 --eval-command COMMAND, -ex COMMAND
2424 Execute a single GDB CLI command. This may be
2425 specified multiple times and in conjunction
2426 with the --command (-x) option.
2428 * Deprecated commands removed
2430 The following commands, that were deprecated in 2000, have been
2434 set|show arm disassembly-flavor set|show arm disassembler
2435 othernames set arm disassembler
2436 set|show remotedebug set|show debug remote
2437 set|show archdebug set|show debug arch
2438 set|show eventdebug set|show debug event
2441 * New BSD user-level threads support
2443 It is now possible to debug programs using the user-level threads
2444 library on OpenBSD and FreeBSD. Currently supported (target)
2447 FreeBSD/amd64 x86_64-*-freebsd*
2448 FreeBSD/i386 i386-*-freebsd*
2449 OpenBSD/i386 i386-*-openbsd*
2451 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2452 are not yet supported.
2454 * New support for Matsushita MN10300 w/sim added
2455 (Work in progress). mn10300-elf.
2457 * REMOVED configurations and files
2459 VxWorks and the XDR protocol *-*-vxworks
2460 Motorola MCORE mcore-*-*
2461 National Semiconductor NS32000 ns32k-*-*
2463 * New "set print array-indexes" command
2465 After turning this setting "on", GDB prints the index of each element
2466 when displaying arrays. The default is "off" to preserve the previous
2469 * VAX floating point support
2471 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2473 * User-defined command support
2475 In addition to using $arg0..$arg9 for argument passing, it is now possible
2476 to use $argc to determine now many arguments have been passed. See the
2477 section on user-defined commands in the user manual for more information.
2479 *** Changes in GDB 6.3:
2481 * New command line option
2483 GDB now accepts -l followed by a number to set the timeout for remote
2486 * GDB works with GCC -feliminate-dwarf2-dups
2488 GDB now supports a more compact representation of DWARF-2 debug
2489 information using DW_FORM_ref_addr references. These are produced
2490 by GCC with the option -feliminate-dwarf2-dups and also by some
2491 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2492 to use -feliminate-dwarf2-dups.
2494 * Internationalization
2496 When supported by the host system, GDB will be built with
2497 internationalization (libintl). The task of marking up the sources is
2498 continued, we're looking forward to our first translation.
2502 Initial support for debugging programs compiled with the GNAT
2503 implementation of the Ada programming language has been integrated
2504 into GDB. In this release, support is limited to expression evaluation.
2506 * New native configurations
2508 GNU/Linux/m32r m32r-*-linux-gnu
2512 GDB's remote protocol now includes support for the 'p' packet. This
2513 packet is used to fetch individual registers from a remote inferior.
2515 * END-OF-LIFE registers[] compatibility module
2517 GDB's internal register infrastructure has been completely rewritten.
2518 The new infrastructure making possible the implementation of key new
2519 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2522 GDB 6.3 will be the last release to include the the registers[]
2523 compatibility module that allowed out-of-date configurations to
2524 continue to work. This change directly impacts the following
2534 powerpc bdm protocol
2536 Unless there is activity to revive these configurations, they will be
2537 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2539 * OBSOLETE configurations and files
2541 Configurations that have been declared obsolete in this release have
2542 been commented out. Unless there is activity to revive these
2543 configurations, the next release of GDB will have their sources
2544 permanently REMOVED.
2553 *** Changes in GDB 6.2.1:
2555 * MIPS `break main; run' gave an heuristic-fence-post warning
2557 When attempting to run even a simple program, a warning about
2558 heuristic-fence-post being hit would be reported. This problem has
2561 * MIPS IRIX 'long double' crashed GDB
2563 When examining a long double variable, GDB would get a segmentation
2564 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2565 IRIX long double values).
2569 A bug in the VAX stack code was causing problems with the "next"
2570 command. This problem has been fixed.
2572 *** Changes in GDB 6.2:
2574 * Fix for ``many threads''
2576 On GNU/Linux systems that use the NPTL threads library, a program
2577 rapidly creating and deleting threads would confuse GDB leading to the
2580 ptrace: No such process.
2581 thread_db_get_info: cannot get thread info: generic error
2583 This problem has been fixed.
2585 * "-async" and "-noasync" options removed.
2587 Support for the broken "-noasync" option has been removed (it caused
2590 * New ``start'' command.
2592 This command runs the program until the begining of the main procedure.
2594 * New BSD Kernel Data Access Library (libkvm) interface
2596 Using ``target kvm'' it is now possible to debug kernel core dumps and
2597 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2598 platforms. Currently supported (native-only) configurations are:
2600 FreeBSD/amd64 x86_64-*-freebsd*
2601 FreeBSD/i386 i?86-*-freebsd*
2602 NetBSD/i386 i?86-*-netbsd*
2603 NetBSD/m68k m68*-*-netbsd*
2604 NetBSD/sparc sparc-*-netbsd*
2605 OpenBSD/amd64 x86_64-*-openbsd*
2606 OpenBSD/i386 i?86-*-openbsd*
2607 OpenBSD/m68k m68*-openbsd*
2608 OpenBSD/sparc sparc-*-openbsd*
2610 * Signal trampoline code overhauled
2612 Many generic problems with GDB's signal handling code have been fixed.
2613 These include: backtraces through non-contiguous stacks; recognition
2614 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2615 call; backtrace through a signal trampoline; step into and out of
2616 signal handlers; and single-stepping in the signal trampoline.
2618 Please note that kernel bugs are a limiting factor here. These
2619 features have been shown to work on an s390 GNU/Linux system that
2620 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2622 * Cygwin support for DWARF 2 added.
2624 * New native configurations
2626 GNU/Linux/hppa hppa*-*-linux*
2627 OpenBSD/hppa hppa*-*-openbsd*
2628 OpenBSD/m68k m68*-*-openbsd*
2629 OpenBSD/m88k m88*-*-openbsd*
2630 OpenBSD/powerpc powerpc-*-openbsd*
2631 NetBSD/vax vax-*-netbsd*
2632 OpenBSD/vax vax-*-openbsd*
2634 * END-OF-LIFE frame compatibility module
2636 GDB's internal frame infrastructure has been completely rewritten.
2637 The new infrastructure making it possible to support key new features
2638 including DWARF 2 Call Frame Information. To aid in the task of
2639 migrating old configurations to this new infrastructure, a
2640 compatibility module, that allowed old configurations to continue to
2641 work, was also included.
2643 GDB 6.2 will be the last release to include this frame compatibility
2644 module. This change directly impacts the following configurations:
2654 Unless there is activity to revive these configurations, they will be
2655 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2657 * REMOVED configurations and files
2659 Sun 3, running SunOS 3 m68*-*-sunos3*
2660 Sun 3, running SunOS 4 m68*-*-sunos4*
2661 Sun 2, running SunOS 3 m68000-*-sunos3*
2662 Sun 2, running SunOS 4 m68000-*-sunos4*
2663 Motorola 680x0 running LynxOS m68*-*-lynxos*
2664 AT&T 3b1/Unix pc m68*-att-*
2665 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2666 decstation mips-dec-* mips-little-*
2667 riscos mips-*-riscos* mips-*-sysv*
2668 sonymips mips-sony-*
2669 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2671 *** Changes in GDB 6.1.1:
2673 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2675 The TUI (Text-mode User Interface) is now built as part of a default
2676 GDB configuration. It is enabled by either selecting the TUI with the
2677 command line option "-i=tui" or by running the separate "gdbtui"
2678 program. For more information on the TUI, see the manual "Debugging
2681 * Pending breakpoint support (also included in GDB 6.1)
2683 Support has been added to allow you to specify breakpoints in shared
2684 libraries that have not yet been loaded. If a breakpoint location
2685 cannot be found, and the "breakpoint pending" option is set to auto,
2686 GDB queries you if you wish to make the breakpoint pending on a future
2687 shared-library load. If and when GDB resolves the breakpoint symbol,
2688 the pending breakpoint is removed as one or more regular breakpoints
2691 Pending breakpoints are very useful for GCJ Java debugging.
2693 * Fixed ISO-C build problems
2695 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2696 non ISO-C code that stopped them being built using a more strict ISO-C
2697 compiler (e.g., IBM's C compiler).
2699 * Fixed build problem on IRIX 5
2701 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2702 wasn't able to compile compile on an IRIX 5 system.
2704 * Added execute permission to gdb/gdbserver/configure
2706 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2707 permission. This bug would cause configure to fail on a number of
2708 systems (Solaris, IRIX). Ref: server/519.
2710 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2712 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2713 has been updated to use constant array sizes.
2715 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2717 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2718 its generated DWARF Call Frame Info. This encoding was causing GDB to
2719 panic, that panic has been fixed. Ref: gdb/1628.
2721 * Fixed a problem when examining parameters in shared library code.
2723 When examining parameters in optimized shared library code generated
2724 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2725 not available''. GDB now correctly displays the variable's value.
2727 *** Changes in GDB 6.1:
2729 * Removed --with-mmalloc
2731 Support for the mmalloc memory manager has been removed, as it
2732 conflicted with the internal gdb byte cache.
2734 * Changes in AMD64 configurations
2736 The AMD64 target now includes the %cs and %ss registers. As a result
2737 the AMD64 remote protocol has changed; this affects the floating-point
2738 and SSE registers. If you rely on those registers for your debugging,
2739 you should upgrade gdbserver on the remote side.
2741 * Revised SPARC target
2743 The SPARC target has been completely revised, incorporating the
2744 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2745 support for LynxOS and SunOS 4 has been dropped. Calling functions
2746 from within GDB on operating systems with a non-executable stack
2747 (Solaris, OpenBSD) now works.
2751 GDB has a new C++ demangler which does a better job on the mangled
2752 names generated by current versions of g++. It also runs faster, so
2753 with this and other changes gdb should now start faster on large C++
2756 * DWARF 2 Location Expressions
2758 GDB support for location expressions has been extended to support function
2759 arguments and frame bases. Older versions of GDB could crash when they
2762 * C++ nested types and namespaces
2764 GDB's support for nested types and namespaces in C++ has been
2765 improved, especially if you use the DWARF 2 debugging format. (This
2766 is the default for recent versions of GCC on most platforms.)
2767 Specifically, if you have a class "Inner" defined within a class or
2768 namespace "Outer", then GDB realizes that the class's name is
2769 "Outer::Inner", not simply "Inner". This should greatly reduce the
2770 frequency of complaints about not finding RTTI symbols. In addition,
2771 if you are stopped at inside of a function defined within a namespace,
2772 GDB modifies its name lookup accordingly.
2774 * New native configurations
2776 NetBSD/amd64 x86_64-*-netbsd*
2777 OpenBSD/amd64 x86_64-*-openbsd*
2778 OpenBSD/alpha alpha*-*-openbsd*
2779 OpenBSD/sparc sparc-*-openbsd*
2780 OpenBSD/sparc64 sparc64-*-openbsd*
2782 * New debugging protocols
2784 M32R with SDI protocol m32r-*-elf*
2786 * "set prompt-escape-char" command deleted.
2788 The command "set prompt-escape-char" has been deleted. This command,
2789 and its very obscure effet on GDB's prompt, was never documented,
2790 tested, nor mentioned in the NEWS file.
2792 * OBSOLETE configurations and files
2794 Configurations that have been declared obsolete in this release have
2795 been commented out. Unless there is activity to revive these
2796 configurations, the next release of GDB will have their sources
2797 permanently REMOVED.
2799 Sun 3, running SunOS 3 m68*-*-sunos3*
2800 Sun 3, running SunOS 4 m68*-*-sunos4*
2801 Sun 2, running SunOS 3 m68000-*-sunos3*
2802 Sun 2, running SunOS 4 m68000-*-sunos4*
2803 Motorola 680x0 running LynxOS m68*-*-lynxos*
2804 AT&T 3b1/Unix pc m68*-att-*
2805 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2806 decstation mips-dec-* mips-little-*
2807 riscos mips-*-riscos* mips-*-sysv*
2808 sonymips mips-sony-*
2809 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2811 * REMOVED configurations and files
2813 SGI Irix-4.x mips-sgi-irix4 or iris4
2814 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2815 Z8000 simulator z8k-zilog-none or z8ksim
2816 Matsushita MN10200 w/simulator mn10200-*-*
2817 H8/500 simulator h8500-hitachi-hms or h8500hms
2818 HP/PA running BSD hppa*-*-bsd*
2819 HP/PA running OSF/1 hppa*-*-osf*
2820 HP/PA Pro target hppa*-*-pro*
2821 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2822 386BSD i[3456]86-*-bsd*
2823 Sequent family i[3456]86-sequent-sysv4*
2824 i[3456]86-sequent-sysv*
2825 i[3456]86-sequent-bsd*
2826 SPARC running LynxOS sparc-*-lynxos*
2827 SPARC running SunOS 4 sparc-*-sunos4*
2828 Tsqware Sparclet sparclet-*-*
2829 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2831 *** Changes in GDB 6.0:
2835 Support for debugging the Objective-C programming language has been
2836 integrated into GDB.
2838 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2840 DWARF 2's Call Frame Information makes available compiler generated
2841 information that more exactly describes the program's run-time stack.
2842 By using this information, GDB is able to provide more robust stack
2845 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2846 have been updated to use a new backtrace mechanism which includes
2847 DWARF 2 CFI support.
2851 GDB's remote protocol has been extended to include support for hosted
2852 file I/O (where the remote target uses GDB's file system). See GDB's
2853 remote protocol documentation for details.
2855 * All targets using the new architecture framework.
2857 All of GDB's targets have been updated to use the new internal
2858 architecture framework. The way is now open for future GDB releases
2859 to include cross-architecture native debugging support (i386 on amd64,
2862 * GNU/Linux's Thread Local Storage (TLS)
2864 GDB now includes support for for the GNU/Linux implementation of
2865 per-thread variables.
2867 * GNU/Linux's Native POSIX Thread Library (NPTL)
2869 GDB's thread code has been updated to work with either the new
2870 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2872 * Separate debug info.
2874 GDB, in conjunction with BINUTILS, now supports a mechanism for
2875 automatically loading debug information from a separate file. Instead
2876 of shipping full debug and non-debug versions of system libraries,
2877 system integrators can now instead ship just the stripped libraries
2878 and optional debug files.
2880 * DWARF 2 Location Expressions
2882 DWARF 2 Location Expressions allow the compiler to more completely
2883 describe the location of variables (even in optimized code) to the
2886 GDB now includes preliminary support for location expressions (support
2887 for DW_OP_piece is still missing).
2891 A number of long standing bugs that caused GDB to die while starting a
2892 Java application have been fixed. GDB's Java support is now
2893 considered "useable".
2895 * GNU/Linux support for fork, vfork, and exec.
2897 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2898 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2901 * GDB supports logging output to a file
2903 There are two new commands, "set logging" and "show logging", which can be
2904 used to capture GDB's output to a file.
2906 * The meaning of "detach" has changed for gdbserver
2908 The "detach" command will now resume the application, as documented. To
2909 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2912 * d10v, m68hc11 `regs' command deprecated
2914 The `info registers' command has been updated so that it displays the
2915 registers using a format identical to the old `regs' command.
2919 A new command, "maint set profile on/off", has been added. This command can
2920 be used to enable or disable profiling while running GDB, to profile a
2921 session or a set of commands. In addition there is a new configure switch,
2922 "--enable-profiling", which will cause GDB to be compiled with profiling
2923 data, for more informative profiling results.
2925 * Default MI syntax changed to "mi2".
2927 The default MI (machine interface) syntax, enabled by the command line
2928 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2929 "mi1", can be enabled by specifying the option "-i=mi1".
2931 Support for the original "mi0" syntax (included in GDB 5.0) has been
2934 Fix for gdb/192: removed extraneous space when displaying frame level.
2935 Fix for gdb/672: update changelist is now output in mi list format.
2936 Fix for gdb/702: a -var-assign that updates the value now shows up
2937 in a subsequent -var-update.
2939 * New native configurations.
2941 FreeBSD/amd64 x86_64-*-freebsd*
2943 * Multi-arched targets.
2945 HP/PA HPUX11 hppa*-*-hpux*
2946 Renesas M32R/D w/simulator m32r-*-elf*
2948 * OBSOLETE configurations and files
2950 Configurations that have been declared obsolete in this release have
2951 been commented out. Unless there is activity to revive these
2952 configurations, the next release of GDB will have their sources
2953 permanently REMOVED.
2955 Z8000 simulator z8k-zilog-none or z8ksim
2956 Matsushita MN10200 w/simulator mn10200-*-*
2957 H8/500 simulator h8500-hitachi-hms or h8500hms
2958 HP/PA running BSD hppa*-*-bsd*
2959 HP/PA running OSF/1 hppa*-*-osf*
2960 HP/PA Pro target hppa*-*-pro*
2961 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2962 Sequent family i[3456]86-sequent-sysv4*
2963 i[3456]86-sequent-sysv*
2964 i[3456]86-sequent-bsd*
2965 Tsqware Sparclet sparclet-*-*
2966 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2968 * REMOVED configurations and files
2971 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2972 IBM AIX PS/2 i[3456]86-*-aix
2973 i386 running Mach 3.0 i[3456]86-*-mach3*
2974 i386 running Mach i[3456]86-*-mach*
2975 i386 running OSF/1 i[3456]86-*osf1mk*
2976 HP/Apollo 68k Family m68*-apollo*-sysv*,
2978 m68*-hp-bsd*, m68*-hp-hpux*
2979 Argonaut Risc Chip (ARC) arc-*-*
2980 Mitsubishi D30V d30v-*-*
2981 Fujitsu FR30 fr30-*-elf*
2982 OS/9000 i[34]86-*-os9k
2983 I960 with MON960 i960-*-coff
2985 * MIPS $fp behavior changed
2987 The convenience variable $fp, for the MIPS, now consistently returns
2988 the address of the current frame's base. Previously, depending on the
2989 context, $fp could refer to either $sp or the current frame's base
2990 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2991 The GNU Source-Level Debugger''.
2993 *** Changes in GDB 5.3:
2995 * GNU/Linux shared library multi-threaded performance improved.
2997 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2998 `/proc', in preference to `ptrace' for memory reads. This may result
2999 in an improvement in the start-up time of multi-threaded, shared
3000 library applications when run under GDB. One GDB user writes: ``loads
3001 shared libs like mad''.
3003 * ``gdbserver'' now supports multi-threaded applications on some targets
3005 Support for debugging multi-threaded applications which use
3006 the GNU/Linux LinuxThreads package has been added for
3007 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3008 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3010 * GDB now supports C/C++ preprocessor macros.
3012 GDB now expands preprocessor macro invocations in C/C++ expressions,
3013 and provides various commands for showing macro definitions and how
3016 The new command `macro expand EXPRESSION' expands any macro
3017 invocations in expression, and shows the result.
3019 The new command `show macro MACRO-NAME' shows the definition of the
3020 macro named MACRO-NAME, and where it was defined.
3022 Most compilers don't include information about macros in the debugging
3023 information by default. In GCC 3.1, for example, you need to compile
3024 your program with the options `-gdwarf-2 -g3'. If the macro
3025 information is present in the executable, GDB will read it.
3027 * Multi-arched targets.
3029 DEC Alpha (partial) alpha*-*-*
3030 DEC VAX (partial) vax-*-*
3032 National Semiconductor NS32000 (partial) ns32k-*-*
3033 Motorola 68000 (partial) m68k-*-*
3034 Motorola MCORE mcore-*-*
3038 Fujitsu FRV architecture added by Red Hat frv*-*-*
3041 * New native configurations
3043 Alpha NetBSD alpha*-*-netbsd*
3044 SH NetBSD sh*-*-netbsdelf*
3045 MIPS NetBSD mips*-*-netbsd*
3046 UltraSPARC NetBSD sparc64-*-netbsd*
3048 * OBSOLETE configurations and files
3050 Configurations that have been declared obsolete in this release have
3051 been commented out. Unless there is activity to revive these
3052 configurations, the next release of GDB will have their sources
3053 permanently REMOVED.
3055 Mitsubishi D30V d30v-*-*
3056 OS/9000 i[34]86-*-os9k
3057 IBM AIX PS/2 i[3456]86-*-aix
3058 Fujitsu FR30 fr30-*-elf*
3059 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3060 Argonaut Risc Chip (ARC) arc-*-*
3061 i386 running Mach 3.0 i[3456]86-*-mach3*
3062 i386 running Mach i[3456]86-*-mach*
3063 i386 running OSF/1 i[3456]86-*osf1mk*
3064 HP/Apollo 68k Family m68*-apollo*-sysv*,
3066 m68*-hp-bsd*, m68*-hp-hpux*
3067 I960 with MON960 i960-*-coff
3069 * OBSOLETE languages
3071 CHILL, a Pascal like language used by telecommunications companies.
3073 * REMOVED configurations and files
3075 AMD 29k family via UDI a29k-amd-udi, udi29k
3076 A29K VxWorks a29k-*-vxworks
3077 AMD 29000 embedded, using EBMON a29k-none-none
3078 AMD 29000 embedded with COFF a29k-none-coff
3079 AMD 29000 embedded with a.out a29k-none-aout
3081 testsuite/gdb.hp/gdb.threads-hp/ directory
3083 * New command "set max-user-call-depth <nnn>"
3085 This command allows the user to limit the call depth of user-defined
3086 commands. The default is 1024.
3088 * Changes in FreeBSD/i386 native debugging.
3090 Support for the "generate-core-file" has been added.
3092 * New commands "dump", "append", and "restore".
3094 These commands allow data to be copied from target memory
3095 to a bfd-format or binary file (dump and append), and back
3096 from a file into memory (restore).
3098 * Improved "next/step" support on multi-processor Alpha Tru64.
3100 The previous single-step mechanism could cause unpredictable problems,
3101 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3102 of a software single-step mechanism prevents this.
3104 *** Changes in GDB 5.2.1:
3112 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3113 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3114 Fix, by Joel Brobecker imported from mainline.
3116 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3117 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3118 Fix, by Fred Fish, imported from mainline.
3120 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3121 Surprisingly enough, it works now.
3122 By Michal Ludvig, imported from mainline.
3124 i386 hardware watchpoint support:
3125 avoid misses on second run for some targets.
3126 By Pierre Muller, imported from mainline.
3128 *** Changes in GDB 5.2:
3130 * New command "set trust-readonly-sections on[off]".
3132 This command is a hint that tells gdb that read-only sections
3133 really are read-only (ie. that their contents will not change).
3134 In this mode, gdb will go to the object file rather than the
3135 target to read memory from read-only sections (such as ".text").
3136 This can be a significant performance improvement on some
3137 (notably embedded) targets.
3139 * New command "generate-core-file" (or "gcore").
3141 This new gdb command allows the user to drop a core file of the child
3142 process state at any time. So far it's been implemented only for
3143 GNU/Linux and Solaris, but should be relatively easily ported to other
3144 hosts. Argument is core file name (defaults to core.<pid>).
3146 * New command line option
3148 GDB now accepts --pid or -p followed by a process id.
3150 * Change in command line behavior -- corefiles vs. process ids.
3152 There is a subtle behavior in the way in which GDB handles
3153 command line arguments. The first non-flag argument is always
3154 a program to debug, but the second non-flag argument may either
3155 be a corefile or a process id. Previously, GDB would attempt to
3156 open the second argument as a corefile, and if that failed, would
3157 issue a superfluous error message and then attempt to attach it as
3158 a process. Now, if the second argument begins with a non-digit,
3159 it will be treated as a corefile. If it begins with a digit,
3160 GDB will attempt to attach it as a process, and if no such process
3161 is found, will then attempt to open it as a corefile.
3163 * Changes in ARM configurations.
3165 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3166 configuration is fully multi-arch.
3168 * New native configurations
3170 ARM NetBSD arm*-*-netbsd*
3171 x86 OpenBSD i[3456]86-*-openbsd*
3172 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3173 Sparc64 running FreeBSD sparc64-*-freebsd*
3177 Sanyo XStormy16 xstormy16-elf
3179 * OBSOLETE configurations and files
3181 Configurations that have been declared obsolete in this release have
3182 been commented out. Unless there is activity to revive these
3183 configurations, the next release of GDB will have their sources
3184 permanently REMOVED.
3186 AMD 29k family via UDI a29k-amd-udi, udi29k
3187 A29K VxWorks a29k-*-vxworks
3188 AMD 29000 embedded, using EBMON a29k-none-none
3189 AMD 29000 embedded with COFF a29k-none-coff
3190 AMD 29000 embedded with a.out a29k-none-aout
3192 testsuite/gdb.hp/gdb.threads-hp/ directory
3194 * REMOVED configurations and files
3196 TI TMS320C80 tic80-*-*
3198 PowerPC Solaris powerpcle-*-solaris*
3199 PowerPC Windows NT powerpcle-*-cygwin32
3200 PowerPC Netware powerpc-*-netware*
3201 Harris/CXUX m88k m88*-harris-cxux*
3202 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3203 ns32k-utek-sysv* ns32k-utek-*
3204 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3205 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3206 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3207 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3208 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3210 * Changes to command line processing
3212 The new `--args' feature can be used to specify command-line arguments
3213 for the inferior from gdb's command line.
3215 * Changes to key bindings
3217 There is a new `operate-and-get-next' function bound to `C-o'.
3219 *** Changes in GDB 5.1.1
3221 Fix compile problem on DJGPP.
3223 Fix a problem with floating-point registers on the i386 being
3226 Fix to stop GDB crashing on .debug_str debug info.
3228 Numerous documentation fixes.
3230 Numerous testsuite fixes.
3232 *** Changes in GDB 5.1:
3234 * New native configurations
3236 Alpha FreeBSD alpha*-*-freebsd*
3237 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3238 MIPS GNU/Linux mips*-*-linux*
3239 MIPS SGI Irix 6.x mips*-sgi-irix6*
3240 ia64 AIX ia64-*-aix*
3241 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3245 Motorola 68HC11 and 68HC12 m68hc11-elf
3247 UltraSparc running GNU/Linux sparc64-*-linux*
3249 * OBSOLETE configurations and files
3251 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3252 Harris/CXUX m88k m88*-harris-cxux*
3253 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3254 ns32k-utek-sysv* ns32k-utek-*
3255 TI TMS320C80 tic80-*-*
3257 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3258 PowerPC Solaris powerpcle-*-solaris*
3259 PowerPC Windows NT powerpcle-*-cygwin32
3260 PowerPC Netware powerpc-*-netware*
3261 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3262 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3263 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3264 Apple Macintosh (MPW) host N/A
3266 stuff.c (Program to stuff files into a specially prepared space in kdb)
3267 kdb-start.c (Main loop for the standalone kernel debugger)
3269 Configurations that have been declared obsolete in this release have
3270 been commented out. Unless there is activity to revive these
3271 configurations, the next release of GDB will have their sources
3272 permanently REMOVED.
3274 * REMOVED configurations and files
3276 Altos 3068 m68*-altos-*
3277 Convex c1-*-*, c2-*-*
3279 ARM RISCix arm-*-* (as host)
3283 * GDB has been converted to ISO C.
3285 GDB's source code has been converted to ISO C. In particular, the
3286 sources are fully protoized, and rely on standard headers being
3291 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3293 * The MI enabled by default.
3295 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3296 revised and enabled by default. Packages which use GDB as a debugging
3297 engine behind a UI or another front end are encouraged to switch to
3298 using the GDB/MI interface, instead of the old annotations interface
3299 which is now deprecated.
3301 * Support for debugging Pascal programs.
3303 GDB now includes support for debugging Pascal programs. The following
3304 main features are supported:
3306 - Pascal-specific data types such as sets;
3308 - automatic recognition of Pascal sources based on file-name
3311 - Pascal-style display of data types, variables, and functions;
3313 - a Pascal expression parser.
3315 However, some important features are not yet supported.
3317 - Pascal string operations are not supported at all;
3319 - there are some problems with boolean types;
3321 - Pascal type hexadecimal constants are not supported
3322 because they conflict with the internal variables format;
3324 - support for Pascal objects and classes is not full yet;
3326 - unlike Pascal, GDB is case-sensitive for symbol names.
3328 * Changes in completion.
3330 Commands such as `shell', `run' and `set args', which pass arguments
3331 to inferior programs, now complete on file names, similar to what
3332 users expect at the shell prompt.
3334 Commands which accept locations, such as `disassemble', `print',
3335 `breakpoint', `until', etc. now complete on filenames as well as
3336 program symbols. Thus, if you type "break foob TAB", and the source
3337 files linked into the programs include `foobar.c', that file name will
3338 be one of the candidates for completion. However, file names are not
3339 considered for completion after you typed a colon that delimits a file
3340 name from a name of a function in that file, as in "break foo.c:bar".
3342 `set demangle-style' completes on available demangling styles.
3344 * New platform-independent commands:
3346 It is now possible to define a post-hook for a command as well as a
3347 hook that runs before the command. For more details, see the
3348 documentation of `hookpost' in the GDB manual.
3350 * Changes in GNU/Linux native debugging.
3352 Support for debugging multi-threaded programs has been completely
3353 revised for all platforms except m68k and sparc. You can now debug as
3354 many threads as your system allows you to have.
3356 Attach/detach is supported for multi-threaded programs.
3358 Support for SSE registers was added for x86. This doesn't work for
3359 multi-threaded programs though.
3361 * Changes in MIPS configurations.
3363 Multi-arch support is enabled for all MIPS configurations.
3365 GDB can now be built as native debugger on SGI Irix 6.x systems for
3366 debugging n32 executables. (Debugging 64-bit executables is not yet
3369 * Unified support for hardware watchpoints in all x86 configurations.
3371 Most (if not all) native x86 configurations support hardware-assisted
3372 breakpoints and watchpoints in a unified manner. This support
3373 implements debug register sharing between watchpoints, which allows to
3374 put a virtually infinite number of watchpoints on the same address,
3375 and also supports watching regions up to 16 bytes with several debug
3378 The new maintenance command `maintenance show-debug-regs' toggles
3379 debugging print-outs in functions that insert, remove, and test
3380 watchpoints and hardware breakpoints.
3382 * Changes in the DJGPP native configuration.
3384 New command ``info dos sysinfo'' displays assorted information about
3385 the CPU, OS, memory, and DPMI server.
3387 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3388 display information about segment descriptors stored in GDT, LDT, and
3391 New commands ``info dos pde'' and ``info dos pte'' display entries
3392 from Page Directory and Page Tables (for now works with CWSDPMI only).
3393 New command ``info dos address-pte'' displays the Page Table entry for
3394 a given linear address.
3396 GDB can now pass command lines longer than 126 characters to the
3397 program being debugged (requires an update to the libdbg.a library
3398 which is part of the DJGPP development kit).
3400 DWARF2 debug info is now supported.
3402 It is now possible to `step' and `next' through calls to `longjmp'.
3404 * Changes in documentation.
3406 All GDB documentation was converted to GFDL, the GNU Free
3407 Documentation License.
3409 Tracepoints-related commands are now fully documented in the GDB
3412 TUI, the Text-mode User Interface, is now documented in the manual.
3414 Tracepoints-related commands are now fully documented in the GDB
3417 The "GDB Internals" manual now has an index. It also includes
3418 documentation of `ui_out' functions, GDB coding standards, x86
3419 hardware watchpoints, and memory region attributes.
3421 * GDB's version number moved to ``version.in''
3423 The Makefile variable VERSION has been replaced by the file
3424 ``version.in''. People creating GDB distributions should update the
3425 contents of this file.
3429 GUD support is now a standard part of the EMACS distribution.
3431 *** Changes in GDB 5.0:
3433 * Improved support for debugging FP programs on x86 targets
3435 Unified and much-improved support for debugging floating-point
3436 programs on all x86 targets. In particular, ``info float'' now
3437 displays the FP registers in the same format on all x86 targets, with
3438 greater level of detail.
3440 * Improvements and bugfixes in hardware-assisted watchpoints
3442 It is now possible to watch array elements, struct members, and
3443 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3444 on x86 targets no longer erroneously trigger when the address is
3447 * Improvements in the native DJGPP version of GDB
3449 The distribution now includes all the scripts and auxiliary files
3450 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3451 machines ``out of the box''.
3453 The DJGPP version can now debug programs that use signals. It is
3454 possible to catch signals that happened in the debuggee, deliver
3455 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3456 would kill the program being debugged.) Programs that hook hardware
3457 interrupts (keyboard, timer, etc.) can also be debugged.
3459 It is now possible to debug DJGPP programs that redirect their
3460 standard handles or switch them to raw (as opposed to cooked) mode, or
3461 even close them. The command ``run < foo > bar'' works as expected,
3462 and ``info terminal'' reports useful information about the debuggee's
3463 terminal, including raw/cooked mode, redirection, etc.
3465 The DJGPP version now uses termios functions for console I/O, which
3466 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3469 DOS-style file names with drive letters are now fully supported by
3472 It is now possible to debug DJGPP programs that switch their working
3473 directory. It is also possible to rerun the debuggee any number of
3474 times without restarting GDB; thus, you can use the same setup,
3475 breakpoints, etc. for many debugging sessions.
3477 * New native configurations
3479 ARM GNU/Linux arm*-*-linux*
3480 PowerPC GNU/Linux powerpc-*-linux*
3484 Motorola MCore mcore-*-*
3485 x86 VxWorks i[3456]86-*-vxworks*
3486 PowerPC VxWorks powerpc-*-vxworks*
3487 TI TMS320C80 tic80-*-*
3489 * OBSOLETE configurations
3491 Altos 3068 m68*-altos-*
3492 Convex c1-*-*, c2-*-*
3494 ARM RISCix arm-*-* (as host)
3497 Configurations that have been declared obsolete will be commented out,
3498 but the code will be left in place. If there is no activity to revive
3499 these configurations before the next release of GDB, the sources will
3500 be permanently REMOVED.
3502 * Gould support removed
3504 Support for the Gould PowerNode and NP1 has been removed.
3506 * New features for SVR4
3508 On SVR4 native platforms (such as Solaris), if you attach to a process
3509 without first loading a symbol file, GDB will now attempt to locate and
3510 load symbols from the running process's executable file.
3512 * Many C++ enhancements
3514 C++ support has been greatly improved. Overload resolution now works properly
3515 in almost all cases. RTTI support is on the way.
3517 * Remote targets can connect to a sub-program
3519 A popen(3) style serial-device has been added. This device starts a
3520 sub-process (such as a stand-alone simulator) and then communicates
3521 with that. The sub-program to run is specified using the syntax
3522 ``|<program> <args>'' vis:
3524 (gdb) set remotedebug 1
3525 (gdb) target extended-remote |mn10300-elf-sim program-args
3527 * MIPS 64 remote protocol
3529 A long standing bug in the mips64 remote protocol where by GDB
3530 expected certain 32 bit registers (ex SR) to be transfered as 32
3531 instead of 64 bits has been fixed.
3533 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3534 added to provide backward compatibility with older versions of GDB.
3536 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3538 The command ``set remotebinarydownload'' command has been replaced by
3539 ``set remote X-packet''. Other commands in ``set remote'' family
3540 include ``set remote P-packet''.
3542 * Breakpoint commands accept ranges.
3544 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3545 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3546 ``tracepoint passcount'' also accepts a range of tracepoints.
3548 * ``apropos'' command added.
3550 The ``apropos'' command searches through command names and
3551 documentation strings, printing out matches, making it much easier to
3552 try to find a command that does what you are looking for.
3556 A new machine oriented interface (MI) has been added to GDB. This
3557 interface is designed for debug environments running GDB as a separate
3558 process. This is part of the long term libGDB project. See the
3559 "GDB/MI" chapter of the GDB manual for further information. It can be
3560 enabled by configuring with:
3562 .../configure --enable-gdbmi
3564 *** Changes in GDB-4.18:
3566 * New native configurations
3568 HP-UX 10.20 hppa*-*-hpux10.20
3569 HP-UX 11.x hppa*-*-hpux11.0*
3570 M68K GNU/Linux m68*-*-linux*
3574 Fujitsu FR30 fr30-*-elf*
3575 Intel StrongARM strongarm-*-*
3576 Mitsubishi D30V d30v-*-*
3578 * OBSOLETE configurations
3580 Gould PowerNode, NP1 np1-*-*, pn-*-*
3582 Configurations that have been declared obsolete will be commented out,
3583 but the code will be left in place. If there is no activity to revive
3584 these configurations before the next release of GDB, the sources will
3585 be permanently REMOVED.
3589 As a compatibility experiment, GDB's source files buildsym.h and
3590 buildsym.c have been converted to pure standard C, no longer
3591 containing any K&R compatibility code. We believe that all systems in
3592 use today either come with a standard C compiler, or have a GCC port
3593 available. If this is not true, please report the affected
3594 configuration to bug-gdb@gnu.org immediately. See the README file for
3595 information about getting a standard C compiler if you don't have one
3600 GDB now uses readline 2.2.
3602 * set extension-language
3604 You can now control the mapping between filename extensions and source
3605 languages by using the `set extension-language' command. For instance,
3606 you can ask GDB to treat .c files as C++ by saying
3607 set extension-language .c c++
3608 The command `info extensions' lists all of the recognized extensions
3609 and their associated languages.
3611 * Setting processor type for PowerPC and RS/6000
3613 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3614 you can use the `set processor' command to specify what variant of the
3615 PowerPC family you are debugging. The command
3619 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3620 following PowerPC and RS6000 variants:
3622 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3623 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3625 403GC IBM PowerPC 403GC
3626 505 Motorola PowerPC 505
3627 860 Motorola PowerPC 860 or 850
3628 601 Motorola PowerPC 601
3629 602 Motorola PowerPC 602
3630 603 Motorola/IBM PowerPC 603 or 603e
3631 604 Motorola PowerPC 604 or 604e
3632 750 Motorola/IBM PowerPC 750 or 750
3634 At the moment, this command just tells GDB what to name the
3635 special-purpose processor registers. Since almost all the affected
3636 registers are inaccessible to user-level programs, this command is
3637 only useful for remote debugging in its present form.
3641 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3642 more extensive support for HP-UX. Added features include shared
3643 library support, kernel threads and hardware watchpoints for 11.00,
3644 support for HP's ANSI C and C++ compilers, and a compatibility mode
3645 for xdb and dbx commands.
3649 HP's donation includes the new concept of catchpoints, which is a
3650 generalization of the old catch command. On HP-UX, it is now possible
3651 to catch exec, fork, and vfork, as well as library loading.
3653 This means that the existing catch command has changed; its first
3654 argument now specifies the type of catch to be set up. See the
3655 output of "help catch" for a list of catchpoint types.
3657 * Debugging across forks
3659 On HP-UX, you can choose which process to debug when a fork() happens
3664 HP has donated a curses-based terminal user interface (TUI). To get
3665 it, build with --enable-tui. Although this can be enabled for any
3666 configuration, at present it only works for native HP debugging.
3668 * GDB remote protocol additions
3670 A new protocol packet 'X' that writes binary data is now available.
3671 Default behavior is to try 'X', then drop back to 'M' if the stub
3672 fails to respond. The settable variable `remotebinarydownload'
3673 allows explicit control over the use of 'X'.
3675 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3676 full 64-bit address. The command
3678 set remoteaddresssize 32
3680 can be used to revert to the old behaviour. For existing remote stubs
3681 the change should not be noticed, as the additional address information
3684 In order to assist in debugging stubs, you may use the maintenance
3685 command `packet' to send any text string to the stub. For instance,
3687 maint packet heythere
3689 sends the packet "$heythere#<checksum>". Note that it is very easy to
3690 disrupt a debugging session by sending the wrong packet at the wrong
3693 The compare-sections command allows you to compare section data on the
3694 target to what is in the executable file without uploading or
3695 downloading, by comparing CRC checksums.
3697 * Tracing can collect general expressions
3699 You may now collect general expressions at tracepoints. This requires
3700 further additions to the target-side stub; see tracepoint.c and
3701 doc/agentexpr.texi for further details.
3703 * mask-address variable for Mips
3705 For Mips targets, you may control the zeroing of the upper 32 bits of
3706 a 64-bit address by entering `set mask-address on'. This is mainly
3707 of interest to users of embedded R4xxx and R5xxx processors.
3709 * Higher serial baud rates
3711 GDB's serial code now allows you to specify baud rates 57600, 115200,
3712 230400, and 460800 baud. (Note that your host system may not be able
3713 to achieve all of these rates.)
3717 The i960 configuration now includes an initial implementation of a
3718 builtin simulator, contributed by Jim Wilson.
3721 *** Changes in GDB-4.17:
3723 * New native configurations
3725 Alpha GNU/Linux alpha*-*-linux*
3726 Unixware 2.x i[3456]86-unixware2*
3727 Irix 6.x mips*-sgi-irix6*
3728 PowerPC GNU/Linux powerpc-*-linux*
3729 PowerPC Solaris powerpcle-*-solaris*
3730 Sparc GNU/Linux sparc-*-linux*
3731 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3735 Argonaut Risc Chip (ARC) arc-*-*
3736 Hitachi H8/300S h8300*-*-*
3737 Matsushita MN10200 w/simulator mn10200-*-*
3738 Matsushita MN10300 w/simulator mn10300-*-*
3739 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3740 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3741 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3742 Mitsubishi D10V w/simulator d10v-*-*
3743 Mitsubishi M32R/D w/simulator m32r-*-elf*
3744 Tsqware Sparclet sparclet-*-*
3745 NEC V850 w/simulator v850-*-*
3747 * New debugging protocols
3749 ARM with RDI protocol arm*-*-*
3750 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3751 DDB and LSI variants of PMON protocol mips*-*-*
3752 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3753 PowerPC with SDS protocol powerpc{,le}-*-eabi
3754 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3758 All configurations can now understand and use the DWARF 2 debugging
3759 format. The choice is automatic, if the symbol file contains DWARF 2
3764 GDB now includes basic Java language support. This support is
3765 only useful with Java compilers that produce native machine code.
3767 * solib-absolute-prefix and solib-search-path
3769 For SunOS and SVR4 shared libraries, you may now set the prefix for
3770 loading absolute shared library symbol files, and the search path for
3771 locating non-absolute shared library symbol files.
3773 * Live range splitting
3775 GDB can now effectively debug code for which GCC has performed live
3776 range splitting as part of its optimization. See gdb/doc/LRS for
3777 more details on the expected format of the stabs information.
3781 GDB's support for the GNU Hurd, including thread debugging, has been
3782 updated to work with current versions of the Hurd.
3786 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3787 instruction set. ARM GDB automatically detects when Thumb
3788 instructions are in use, and adjusts disassembly and backtracing
3793 GDB's MIPS target configurations now handle the MIP16 16-bit
3798 GDB now includes support for overlays; if an executable has been
3799 linked such that multiple sections are based at the same address, GDB
3800 will decide which section to use for symbolic info. You can choose to
3801 control the decision manually, using overlay commands, or implement
3802 additional target-side support and use "overlay load-target" to bring
3803 in the overlay mapping. Do "help overlay" for more detail.
3807 The command "info symbol <address>" displays information about
3808 the symbol at the specified address.
3812 The standard remote protocol now includes an extension that allows
3813 asynchronous collection and display of trace data. This requires
3814 extensive support in the target-side debugging stub. Tracing mode
3815 includes a new interaction mode in GDB and new commands: see the
3816 file tracepoint.c for more details.
3820 Configurations for embedded MIPS now include a simulator contributed
3821 by Cygnus Solutions. The simulator supports the instruction sets
3822 of most MIPS variants.
3826 Sparc configurations may now include the ERC32 simulator contributed
3827 by the European Space Agency. The simulator is not built into
3828 Sparc targets by default; configure with --enable-sim to include it.
3832 For target configurations that may include multiple variants of a
3833 basic architecture (such as MIPS and SH), you may now set the
3834 architecture explicitly. "set arch" sets, "info arch" lists
3835 the possible architectures.
3837 *** Changes in GDB-4.16:
3839 * New native configurations
3841 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3842 M68K NetBSD m68k-*-netbsd*
3843 PowerPC AIX 4.x powerpc-*-aix*
3844 PowerPC MacOS powerpc-*-macos*
3845 PowerPC Windows NT powerpcle-*-cygwin32
3846 RS/6000 AIX 4.x rs6000-*-aix4*
3850 ARM with RDP protocol arm-*-*
3851 I960 with MON960 i960-*-coff
3852 MIPS VxWorks mips*-*-vxworks*
3853 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3854 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3856 Matra Sparclet sparclet-*-*
3860 The powerpc-eabi configuration now includes the PSIM simulator,
3861 contributed by Andrew Cagney, with assistance from Mike Meissner.
3862 PSIM is a very elaborate model of the PowerPC, including not only
3863 basic instruction set execution, but also details of execution unit
3864 performance and I/O hardware. See sim/ppc/README for more details.
3868 GDB now works with Solaris 2.5.
3870 * Windows 95/NT native
3872 GDB will now work as a native debugger on Windows 95 and Windows NT.
3873 To build it from source, you must use the "gnu-win32" environment,
3874 which uses a DLL to emulate enough of Unix to run the GNU tools.
3875 Further information, binaries, and sources are available at
3876 ftp.cygnus.com, under pub/gnu-win32.
3878 * dont-repeat command
3880 If a user-defined command includes the command `dont-repeat', then the
3881 command will not be repeated if the user just types return. This is
3882 useful if the command is time-consuming to run, so that accidental
3883 extra keystrokes don't run the same command many times.
3885 * Send break instead of ^C
3887 The standard remote protocol now includes an option to send a break
3888 rather than a ^C to the target in order to interrupt it. By default,
3889 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3891 * Remote protocol timeout
3893 The standard remote protocol includes a new variable `remotetimeout'
3894 that allows you to set the number of seconds before GDB gives up trying
3895 to read from the target. The default value is 2.
3897 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3899 By default GDB will automatically keep track of objects as they are
3900 loaded and unloaded by the dynamic linker. By using the command `set
3901 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3902 when shared library events occur, thus allowing you to set breakpoints
3903 in shared libraries which are explicitly loaded by the inferior.
3905 Note this feature does not work on hpux8. On hpux9 you must link
3906 /usr/lib/end.o into your program. This feature should work
3907 automatically on hpux10.
3909 * Irix 5.x hardware watchpoint support
3911 Irix 5 configurations now support the use of hardware watchpoints.
3913 * Mips protocol "SYN garbage limit"
3915 When debugging a Mips target using the `target mips' protocol, you
3916 may set the number of characters that GDB will ignore by setting
3917 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3918 every character. The default value is 1050.
3920 * Recording and replaying remote debug sessions
3922 If you set `remotelogfile' to the name of a file, gdb will write to it
3923 a recording of a remote debug session. This recording may then be
3924 replayed back to gdb using "gdbreplay". See gdbserver/README for
3925 details. This is useful when you have a problem with GDB while doing
3926 remote debugging; you can make a recording of the session and send it
3927 to someone else, who can then recreate the problem.
3929 * Speedups for remote debugging
3931 GDB includes speedups for downloading and stepping MIPS systems using
3932 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3933 and more efficient S-record downloading.
3935 * Memory use reductions and statistics collection
3937 GDB now uses less memory and reports statistics about memory usage.
3938 Try the `maint print statistics' command, for example.
3940 *** Changes in GDB-4.15:
3942 * Psymtabs for XCOFF
3944 The symbol reader for AIX GDB now uses partial symbol tables. This
3945 can greatly improve startup time, especially for large executables.
3947 * Remote targets use caching
3949 Remote targets now use a data cache to speed up communication with the
3950 remote side. The data cache could lead to incorrect results because
3951 it doesn't know about volatile variables, thus making it impossible to
3952 debug targets which use memory mapped I/O devices. `set remotecache
3953 off' turns the the data cache off.
3955 * Remote targets may have threads
3957 The standard remote protocol now includes support for multiple threads
3958 in the target system, using new protocol commands 'H' and 'T'. See
3959 gdb/remote.c for details.
3963 If GDB is configured with `--enable-netrom', then it will include
3964 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3965 acts as though it is a bank of ROM on the target board, but you can
3966 write into it over the network. GDB's support consists only of
3967 support for fast loading into the emulated ROM; to debug, you must use
3968 another protocol, such as standard remote protocol. The usual
3969 sequence is something like
3971 target nrom <netrom-hostname>
3973 target remote <netrom-hostname>:1235
3977 GDB now includes support for the Apple Macintosh, as a host only. It
3978 may be run as either an MPW tool or as a standalone application, and
3979 it can debug through the serial port. All the usual GDB commands are
3980 available, but to the target command, you must supply "serial" as the
3981 device type instead of "/dev/ttyXX". See mpw-README in the main
3982 directory for more information on how to build. The MPW configuration
3983 scripts */mpw-config.in support only a few targets, and only the
3984 mips-idt-ecoff target has been tested.
3988 GDB configuration now uses autoconf. This is not user-visible,
3989 but does simplify configuration and building.
3993 GDB now supports hpux10.
3995 *** Changes in GDB-4.14:
3997 * New native configurations
3999 x86 FreeBSD i[345]86-*-freebsd
4000 x86 NetBSD i[345]86-*-netbsd
4001 NS32k NetBSD ns32k-*-netbsd
4002 Sparc NetBSD sparc-*-netbsd
4006 A29K VxWorks a29k-*-vxworks
4007 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4008 CPU32 EST-300 emulator m68*-*-est*
4009 PowerPC ELF powerpc-*-elf
4012 * Alpha OSF/1 support for procfs
4014 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4015 possible to attach to running processes. As the mounting of the /proc
4016 filesystem is optional on the Alpha, GDB automatically determines
4017 the availability of /proc during startup. This can lead to problems
4018 if /proc is unmounted after GDB has been started.
4020 * Arguments to user-defined commands
4022 User commands may accept up to 10 arguments separated by whitespace.
4023 Arguments are accessed within the user command via $arg0..$arg9. A
4026 print $arg0 + $arg1 + $arg2
4028 To execute the command use:
4031 Defines the command "adder" which prints the sum of its three arguments.
4032 Note the arguments are text substitutions, so they may reference variables,
4033 use complex expressions, or even perform inferior function calls.
4035 * New `if' and `while' commands
4037 This makes it possible to write more sophisticated user-defined
4038 commands. Both commands take a single argument, which is the
4039 expression to evaluate, and must be followed by the commands to
4040 execute, one per line, if the expression is nonzero, the list being
4041 terminated by the word `end'. The `if' command list may include an
4042 `else' word, which causes the following commands to be executed only
4043 if the expression is zero.
4045 * Fortran source language mode
4047 GDB now includes partial support for Fortran 77. It will recognize
4048 Fortran programs and can evaluate a subset of Fortran expressions, but
4049 variables and functions may not be handled correctly. GDB will work
4050 with G77, but does not yet know much about symbols emitted by other
4053 * Better HPUX support
4055 Most debugging facilities now work on dynamic executables for HPPAs
4056 running hpux9 or later. You can attach to running dynamically linked
4057 processes, but by default the dynamic libraries will be read-only, so
4058 for instance you won't be able to put breakpoints in them. To change
4059 that behavior do the following before running the program:
4065 This will cause the libraries to be mapped private and read-write.
4066 To revert to the normal behavior, do this:
4072 You cannot set breakpoints or examine data in the library until after
4073 the library is loaded if the function/data symbols do not have
4076 GDB can now also read debug symbols produced by the HP C compiler on
4077 HPPAs (sorry, no C++, Fortran or 68k support).
4079 * Target byte order now dynamically selectable
4081 You can choose which byte order to use with a target system, via the
4082 commands "set endian big" and "set endian little", and you can see the
4083 current setting by using "show endian". You can also give the command
4084 "set endian auto", in which case GDB will use the byte order
4085 associated with the executable. Currently, only embedded MIPS
4086 configurations support dynamic selection of target byte order.
4088 * New DOS host serial code
4090 This version uses DPMI interrupts to handle buffered I/O, so you
4091 no longer need to run asynctsr when debugging boards connected to
4094 *** Changes in GDB-4.13:
4096 * New "complete" command
4098 This lists all the possible completions for the rest of the line, if it
4099 were to be given as a command itself. This is intended for use by emacs.
4101 * Trailing space optional in prompt
4103 "set prompt" no longer adds a space for you after the prompt you set. This
4104 allows you to set a prompt which ends in a space or one that does not.
4106 * Breakpoint hit counts
4108 "info break" now displays a count of the number of times the breakpoint
4109 has been hit. This is especially useful in conjunction with "ignore"; you
4110 can ignore a large number of breakpoint hits, look at the breakpoint info
4111 to see how many times the breakpoint was hit, then run again, ignoring one
4112 less than that number, and this will get you quickly to the last hit of
4115 * Ability to stop printing at NULL character
4117 "set print null-stop" will cause GDB to stop printing the characters of
4118 an array when the first NULL is encountered. This is useful when large
4119 arrays actually contain only short strings.
4121 * Shared library breakpoints
4123 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4124 breakpoints in shared libraries before the executable is run.
4126 * Hardware watchpoints
4128 There is a new hardware breakpoint for the watch command for sparclite
4129 targets. See gdb/sparclite/hw_breakpoint.note.
4131 Hardware watchpoints are also now supported under GNU/Linux.
4135 Annotations have been added. These are for use with graphical interfaces,
4136 and are still experimental. Currently only gdba.el uses these.
4138 * Improved Irix 5 support
4140 GDB now works properly with Irix 5.2.
4142 * Improved HPPA support
4144 GDB now works properly with the latest GCC and GAS.
4146 * New native configurations
4148 Sequent PTX4 i[34]86-sequent-ptx4
4149 HPPA running OSF/1 hppa*-*-osf*
4150 Atari TT running SVR4 m68*-*-sysv4*
4151 RS/6000 LynxOS rs6000-*-lynxos*
4155 OS/9000 i[34]86-*-os9k
4156 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4159 * Hitachi SH7000 and E7000-PC ICE support
4161 There is now support for communicating with the Hitachi E7000-PC ICE.
4162 This is available automatically when GDB is configured for the SH.
4166 As usual, a variety of small fixes and improvements, both generic
4167 and configuration-specific. See the ChangeLog for more detail.
4169 *** Changes in GDB-4.12:
4171 * Irix 5 is now supported
4175 GDB-4.12 on the HPPA has a number of changes which make it unable
4176 to debug the output from the currently released versions of GCC and
4177 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4178 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4179 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4182 *** Changes in GDB-4.11:
4184 * User visible changes:
4188 The "set remotedebug" option is now consistent between the mips remote
4189 target, remote targets using the gdb-specific protocol, UDI (AMD's
4190 debug protocol for the 29k) and the 88k bug monitor. It is now an
4191 integer specifying a debug level (normally 0 or 1, but 2 means more
4192 debugging info for the mips target).
4194 * DEC Alpha native support
4196 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4197 debug info, but GDB works fairly well with the DEC compiler and should
4198 work with a future GCC release. See the README file for a few
4199 Alpha-specific notes.
4201 * Preliminary thread implementation
4203 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4205 * LynxOS native and target support for 386
4207 This release has been hosted on LynxOS 2.2, and also can be configured
4208 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4211 * Improvements in C++ mangling/demangling.
4213 This release has much better g++ debugging, specifically in name
4214 mangling/demangling, virtual function calls, print virtual table,
4215 call methods, ...etc.
4217 *** Changes in GDB-4.10:
4219 * User visible changes:
4221 Remote debugging using the GDB-specific (`target remote') protocol now
4222 supports the `load' command. This is only useful if you have some
4223 other way of getting the stub to the target system, and you can put it
4224 somewhere in memory where it won't get clobbered by the download.
4226 Filename completion now works.
4228 When run under emacs mode, the "info line" command now causes the
4229 arrow to point to the line specified. Also, "info line" prints
4230 addresses in symbolic form (as well as hex).
4232 All vxworks based targets now support a user settable option, called
4233 vxworks-timeout. This option represents the number of seconds gdb
4234 should wait for responses to rpc's. You might want to use this if
4235 your vxworks target is, perhaps, a slow software simulator or happens
4236 to be on the far side of a thin network line.
4240 This release contains support for using a DEC alpha as a GDB host for
4241 cross debugging. Native alpha debugging is not supported yet.
4244 *** Changes in GDB-4.9:
4248 This is the first GDB release which is accompanied by a matching testsuite.
4249 The testsuite requires installation of dejagnu, which should be available
4250 via ftp from most sites that carry GNU software.
4254 'Cfront' style demangling has had its name changed to 'ARM' style, to
4255 emphasize that it was written from the specifications in the C++ Annotated
4256 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4257 disclaimers, it still generated too much confusion with users attempting to
4258 use gdb with AT&T cfront.
4262 GDB now uses a standard remote interface to a simulator library.
4263 So far, the library contains simulators for the Zilog Z8001/2, the
4264 Hitachi H8/300, H8/500 and Super-H.
4266 * New targets supported
4268 H8/300 simulator h8300-hitachi-hms or h8300hms
4269 H8/500 simulator h8500-hitachi-hms or h8500hms
4270 SH simulator sh-hitachi-hms or sh
4271 Z8000 simulator z8k-zilog-none or z8ksim
4272 IDT MIPS board over serial line mips-idt-ecoff
4274 Cross-debugging to GO32 targets is supported. It requires a custom
4275 version of the i386-stub.c module which is integrated with the
4276 GO32 memory extender.
4278 * New remote protocols
4280 MIPS remote debugging protocol.
4282 * New source languages supported
4284 This version includes preliminary support for Chill, a Pascal like language
4285 used by telecommunications companies. Chill support is also being integrated
4286 into the GNU compiler, but we don't know when it will be publically available.
4289 *** Changes in GDB-4.8:
4291 * HP Precision Architecture supported
4293 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4294 version of this support was available as a set of patches from the
4295 University of Utah. GDB does not support debugging of programs
4296 compiled with the HP compiler, because HP will not document their file
4297 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4298 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4300 Many problems in the preliminary version have been fixed.
4302 * Faster and better demangling
4304 We have improved template demangling and fixed numerous bugs in the GNU style
4305 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4306 character types (wchar_t) are now supported. Demangling of each symbol is now
4307 only done once, and is cached when the symbol table for a file is read in.
4308 This results in a small increase in memory usage for C programs, a moderate
4309 increase in memory usage for C++ programs, and a fantastic speedup in
4312 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4313 from the specifications in the Annotated Reference Manual, which AT&T's
4314 compiler does not actually implement.
4316 * G++ multiple inheritance compiler problem
4318 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4319 inheritance lattices was reworked to properly discover ambiguities. We
4320 recently found an example which causes this new algorithm to fail in a
4321 very subtle way, producing bad debug information for those classes.
4322 The file 'gcc.patch' (in this directory) can be applied to gcc to
4323 circumvent the problem. A future GCC release will contain a complete
4326 The previous G++ debug info problem (mentioned below for the gdb-4.7
4327 release) is fixed in gcc version 2.3.2.
4329 * Improved configure script
4331 The `configure' script will now attempt to guess your system type if
4332 you don't supply a host system type. The old scheme of supplying a
4333 host system triplet is preferable over using this. All the magic is
4334 done in the new `config.guess' script. Examine it for details.
4336 We have also brought our configure script much more in line with the FSF's
4337 version. It now supports the --with-xxx options. In particular,
4338 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4339 The resulting GDB will not be able to read arbitrary object file formats --
4340 only the format ``expected'' to be used on the configured target system.
4341 We hope to make this the default in a future release.
4343 * Documentation improvements
4345 There's new internal documentation on how to modify GDB, and how to
4346 produce clean changes to the code. We implore people to read it
4347 before submitting changes.
4349 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4350 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4351 `info' files are also provided. To build `info' files from scratch,
4352 you will need the latest `makeinfo' release, which will be available in
4353 a future texinfo-X.Y release.
4355 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4356 We're not sure exactly which versions have this problem, but it has
4357 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4358 or better. If that isn't possible, there is a patch in
4359 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4360 around this problem.
4364 GDB now supports array constants that can be used in expressions typed in by
4365 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4366 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4369 The new directory `gdb/sparclite' contains a program that demonstrates
4370 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4372 * New native hosts supported
4374 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4375 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4377 * New targets supported
4379 AMD 29k family via UDI a29k-amd-udi or udi29k
4381 * New file formats supported
4383 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4384 HPUX core files, and SCO 3.2v2 core files.
4388 Attaching to processes now works again; thanks for the many bug reports.
4390 We have also stomped on a bunch of core dumps caused by
4391 printf_filtered("%s") problems.
4393 We eliminated a copyright problem on the rpc and ptrace header files
4394 for VxWorks, which was discovered at the last minute during the 4.7
4395 release. You should now be able to build a VxWorks GDB.
4397 You can now interrupt gdb while an attached process is running. This
4398 will cause the attached process to stop, and give control back to GDB.
4400 We fixed problems caused by using too many file descriptors
4401 for reading symbols from object files and libraries. This was
4402 especially a problem for programs that used many (~100) shared
4405 The `step' command now only enters a subroutine if there is line number
4406 information for the subroutine. Otherwise it acts like the `next'
4407 command. Previously, `step' would enter subroutines if there was
4408 any debugging information about the routine. This avoids problems
4409 when using `cc -g1' on MIPS machines.
4411 * Internal improvements
4413 GDB's internal interfaces have been improved to make it easier to support
4414 debugging of multiple languages in the future.
4416 GDB now uses a common structure for symbol information internally.
4417 Minimal symbols (derived from linkage symbols in object files), partial
4418 symbols (from a quick scan of debug information), and full symbols
4419 contain a common subset of information, making it easier to write
4420 shared code that handles any of them.
4422 * New command line options
4424 We now accept --silent as an alias for --quiet.
4428 The memory-mapped-malloc library is now licensed under the GNU Library
4429 General Public License.
4431 *** Changes in GDB-4.7:
4433 * Host/native/target split
4435 GDB has had some major internal surgery to untangle the support for
4436 hosts and remote targets. Now, when you configure GDB for a remote
4437 target, it will no longer load in all of the support for debugging
4438 local programs on the host. When fully completed and tested, this will
4439 ensure that arbitrary host/target combinations are possible.
4441 The primary conceptual shift is to separate the non-portable code in
4442 GDB into three categories. Host specific code is required any time GDB
4443 is compiled on that host, regardless of the target. Target specific
4444 code relates to the peculiarities of the target, but can be compiled on
4445 any host. Native specific code is everything else: it can only be
4446 built when the host and target are the same system. Child process
4447 handling and core file support are two common `native' examples.
4449 GDB's use of /proc for controlling Unix child processes is now cleaner.
4450 It has been split out into a single module under the `target_ops' vector,
4451 plus two native-dependent functions for each system that uses /proc.
4453 * New hosts supported
4455 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4456 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4457 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4459 * New targets supported
4461 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4462 68030 and CPU32 m68030-*-*, m68332-*-*
4464 * New native hosts supported
4466 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4467 (386bsd is not well tested yet)
4468 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4470 * New file formats supported
4472 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4473 supports reading of `a.out.adobe' object files, which are an a.out
4474 format extended with minimal information about multiple sections.
4478 `show copying' is the same as the old `info copying'.
4479 `show warranty' is the same as `info warrantee'.
4480 These were renamed for consistency. The old commands continue to work.
4482 `info handle' is a new alias for `info signals'.
4484 You can now define pre-command hooks, which attach arbitrary command
4485 scripts to any command. The commands in the hook will be executed
4486 prior to the user's command. You can also create a hook which will be
4487 executed whenever the program stops. See gdb.texinfo.
4491 We now deal with Cfront style name mangling, and can even extract type
4492 info from mangled symbols. GDB can automatically figure out which
4493 symbol mangling style your C++ compiler uses.
4495 Calling of methods and virtual functions has been improved as well.
4499 The crash that occured when debugging Sun Ansi-C compiled binaries is
4500 fixed. This was due to mishandling of the extra N_SO stabs output
4503 We also finally got Ultrix 4.2 running in house, and fixed core file
4504 support, with help from a dozen people on the net.
4506 John M. Farrell discovered that the reason that single-stepping was so
4507 slow on all of the Mips based platforms (primarily SGI and DEC) was
4508 that we were trying to demangle and lookup a symbol used for internal
4509 purposes on every instruction that was being stepped through. Changing
4510 the name of that symbol so that it couldn't be mistaken for a C++
4511 mangled symbol sped things up a great deal.
4513 Rich Pixley sped up symbol lookups in general by getting much smarter
4514 about when C++ symbol mangling is necessary. This should make symbol
4515 completion (TAB on the command line) much faster. It's not as fast as
4516 we'd like, but it's significantly faster than gdb-4.6.
4520 A new user controllable variable 'call_scratch_address' can
4521 specify the location of a scratch area to be used when GDB
4522 calls a function in the target. This is necessary because the
4523 usual method of putting the scratch area on the stack does not work
4524 in systems that have separate instruction and data spaces.
4526 We integrated changes to support the 29k UDI (Universal Debugger
4527 Interface), but discovered at the last minute that we didn't have all
4528 of the appropriate copyright paperwork. We are working with AMD to
4529 resolve this, and hope to have it available soon.
4533 We have sped up the remote serial line protocol, especially for targets
4534 with lots of registers. It now supports a new `expedited status' ('T')
4535 message which can be used in place of the existing 'S' status message.
4536 This allows the remote stub to send only the registers that GDB
4537 needs to make a quick decision about single-stepping or conditional
4538 breakpoints, eliminating the need to fetch the entire register set for
4539 each instruction being stepped through.
4541 The GDB remote serial protocol now implements a write-through cache for
4542 registers, only re-reading the registers if the target has run.
4544 There is also a new remote serial stub for SPARC processors. You can
4545 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4546 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4547 processor with a serial port.
4551 Configure.in files have become much easier to read and modify. A new
4552 `table driven' format makes it more obvious what configurations are
4553 supported, and what files each one uses.
4557 There is a new opcodes library which will eventually contain all of the
4558 disassembly routines and opcode tables. At present, it only contains
4559 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4560 disassembler (binutils/objdump) to share these routines.
4562 The libiberty library is now copylefted under the GNU Library General
4563 Public License. This allows more liberal use, and was done so libg++
4564 can use it. This makes no difference to GDB, since the Library License
4565 grants all the rights from the General Public License.
4569 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4570 reference to the stabs symbol info used by the debugger. It is (as far
4571 as we know) the only published document on this fascinating topic. We
4572 encourage you to read it, compare it to the stabs information on your
4573 system, and send improvements on the document in general (to
4574 bug-gdb@prep.ai.mit.edu).
4576 And, of course, many bugs have been fixed.
4579 *** Changes in GDB-4.6:
4581 * Better support for C++ function names
4583 GDB now accepts as input the "demangled form" of C++ overloaded function
4584 names and member function names, and can do command completion on such names
4585 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4586 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4587 Make use of command completion, it is your friend.
4589 GDB also now accepts a variety of C++ mangled symbol formats. They are
4590 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4591 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4592 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4593 for the list of formats.
4595 * G++ symbol mangling problem
4597 Recent versions of gcc have a bug in how they emit debugging information for
4598 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4599 directory) can be applied to gcc to fix the problem. Alternatively, if you
4600 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4601 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4602 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4605 * New 'maintenance' command
4607 All of the commands related to hacking GDB internals have been moved out of
4608 the main command set, and now live behind the 'maintenance' command. This
4609 can also be abbreviated as 'mt'. The following changes were made:
4611 dump-me -> maintenance dump-me
4612 info all-breakpoints -> maintenance info breakpoints
4613 printmsyms -> maintenance print msyms
4614 printobjfiles -> maintenance print objfiles
4615 printpsyms -> maintenance print psymbols
4616 printsyms -> maintenance print symbols
4618 The following commands are new:
4620 maintenance demangle Call internal GDB demangler routine to
4621 demangle a C++ link name and prints the result.
4622 maintenance print type Print a type chain for a given symbol
4624 * Change to .gdbinit file processing
4626 We now read the $HOME/.gdbinit file before processing the argv arguments
4627 (e.g. reading symbol files or core files). This allows global parameters to
4628 be set, which will apply during the symbol reading. The ./.gdbinit is still
4629 read after argv processing.
4631 * New hosts supported
4633 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4635 GNU/Linux support i386-unknown-linux or linux
4637 We are also including code to support the HP/PA running BSD and HPUX. This
4638 is almost guaranteed not to work, as we didn't have time to test or build it
4639 for this release. We are including it so that the more adventurous (or
4640 masochistic) of you can play with it. We also had major problems with the
4641 fact that the compiler that we got from HP doesn't support the -g option.
4644 * New targets supported
4646 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4648 * More smarts about finding #include files
4650 GDB now remembers the compilation directory for all include files, and for
4651 all files from which C is generated (like yacc and lex sources). This
4652 greatly improves GDB's ability to find yacc/lex sources, and include files,
4653 especially if you are debugging your program from a directory different from
4654 the one that contains your sources.
4656 We also fixed a bug which caused difficulty with listing and setting
4657 breakpoints in include files which contain C code. (In the past, you had to
4658 try twice in order to list an include file that you hadn't looked at before.)
4660 * Interesting infernals change
4662 GDB now deals with arbitrary numbers of sections, where the symbols for each
4663 section must be relocated relative to that section's landing place in the
4664 target's address space. This work was needed to support ELF with embedded
4665 stabs used by Solaris-2.0.
4667 * Bug fixes (of course!)
4669 There have been loads of fixes for the following things:
4670 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4671 i960, stabs, DOS(GO32), procfs, etc...
4673 See the ChangeLog for details.
4675 *** Changes in GDB-4.5:
4677 * New machines supported (host and target)
4679 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4681 SGI Irix-4.x mips-sgi-irix4 or iris4
4683 * New malloc package
4685 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4686 Mmalloc is capable of handling mutiple heaps of memory. It is also
4687 capable of saving a heap to a file, and then mapping it back in later.
4688 This can be used to greatly speedup the startup of GDB by using a
4689 pre-parsed symbol table which lives in a mmalloc managed heap. For
4690 more details, please read mmalloc/mmalloc.texi.
4694 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4695 'help info proc' for details.
4697 * MIPS ecoff symbol table format
4699 The code that reads MIPS symbol table format is now supported on all hosts.
4700 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4703 * File name changes for MS-DOS
4705 Many files in the config directories have been renamed to make it easier to
4706 support GDB on MS-DOSe systems (which have very restrictive file name
4707 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4708 environment) is close to working but has some remaining problems. Note
4709 that debugging of DOS programs is not supported, due to limitations
4710 in the ``operating system'', but it can be used to host cross-debugging.
4712 * Cross byte order fixes
4714 Many fixes have been made to support cross debugging of Sparc and MIPS
4715 targets from hosts whose byte order differs.
4717 * New -mapped and -readnow options
4719 If memory-mapped files are available on your system through the 'mmap'
4720 system call, you can use the -mapped option on the `file' or
4721 `symbol-file' commands to cause GDB to write the symbols from your
4722 program into a reusable file. If the program you are debugging is
4723 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4724 Future GDB debugging sessions will notice the presence of this file,
4725 and will quickly map in symbol information from it, rather than reading
4726 the symbol table from the executable program. Using the '-mapped'
4727 option in a GDB `file' or `symbol-file' command has the same effect as
4728 starting GDB with the '-mapped' command-line option.
4730 You can cause GDB to read the entire symbol table immediately by using
4731 the '-readnow' option with any of the commands that load symbol table
4732 information (or on the GDB command line). This makes the command
4733 slower, but makes future operations faster.
4735 The -mapped and -readnow options are typically combined in order to
4736 build a `fred.syms' file that contains complete symbol information.
4737 A simple GDB invocation to do nothing but build a `.syms' file for future
4740 gdb -batch -nx -mapped -readnow programname
4742 The `.syms' file is specific to the host machine on which GDB is run.
4743 It holds an exact image of GDB's internal symbol table. It cannot be
4744 shared across multiple host platforms.
4746 * longjmp() handling
4748 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4749 siglongjmp() without losing control. This feature has not yet been ported to
4750 all systems. It currently works on many 386 platforms, all MIPS-based
4751 platforms (SGI, DECstation, etc), and Sun3/4.
4755 Preliminary work has been put in to support the new Solaris OS from Sun. At
4756 this time, it can control and debug processes, but it is not capable of
4761 As always, many many bug fixes. The major areas were with g++, and mipsread.
4762 People using the MIPS-based platforms should experience fewer mysterious
4763 crashes and trashed symbol tables.
4765 *** Changes in GDB-4.4:
4767 * New machines supported (host and target)
4769 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4771 BSD Reno on Vax vax-dec-bsd
4772 Ultrix on Vax vax-dec-ultrix
4774 * New machines supported (target)
4776 AMD 29000 embedded, using EBMON a29k-none-none
4780 GDB continues to improve its handling of C++. `References' work better.
4781 The demangler has also been improved, and now deals with symbols mangled as
4782 per the Annotated C++ Reference Guide.
4784 GDB also now handles `stabs' symbol information embedded in MIPS
4785 `ecoff' symbol tables. Since the ecoff format was not easily
4786 extensible to handle new languages such as C++, this appeared to be a
4787 good way to put C++ debugging info into MIPS binaries. This option
4788 will be supported in the GNU C compiler, version 2, when it is
4791 * New features for SVR4
4793 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4794 shared libraries. Debugging dynamically linked programs should present
4795 only minor differences from debugging statically linked programs.
4797 The `info proc' command will print out information about any process
4798 on an SVR4 system (including the one you are debugging). At the moment,
4799 it prints the address mappings of the process.
4801 If you bring up GDB on another SVR4 system, please send mail to
4802 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4804 * Better dynamic linking support in SunOS
4806 Reading symbols from shared libraries which contain debugging symbols
4807 now works properly. However, there remain issues such as automatic
4808 skipping of `transfer vector' code during function calls, which
4809 make it harder to debug code in a shared library, than to debug the
4810 same code linked statically.
4814 GDB is now using the latest `getopt' routines from the FSF. This
4815 version accepts the -- prefix for options with long names. GDB will
4816 continue to accept the old forms (-option and +option) as well.
4817 Various single letter abbreviations for options have been explicity
4818 added to the option table so that they won't get overshadowed in the
4819 future by other options that begin with the same letter.
4823 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4824 Many assorted bugs have been handled. Many more remain to be handled.
4825 See the various ChangeLog files (primarily in gdb and bfd) for details.
4828 *** Changes in GDB-4.3:
4830 * New machines supported (host and target)
4832 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4833 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4834 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4836 * Almost SCO Unix support
4838 We had hoped to support:
4839 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4840 (except for core file support), but we discovered very late in the release
4841 that it has problems with process groups that render gdb unusable. Sorry
4842 about that. I encourage people to fix it and post the fixes.
4844 * Preliminary ELF and DWARF support
4846 GDB can read ELF object files on System V Release 4, and can handle
4847 debugging records for C, in DWARF format, in ELF files. This support
4848 is preliminary. If you bring up GDB on another SVR4 system, please
4849 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4854 GDB now uses the latest `readline' library. One user-visible change
4855 is that two tabs will list possible command completions, which previously
4856 required typing M-? (meta-question mark, or ESC ?).
4860 The `stepi' bug that many of you noticed has been squashed.
4861 Many bugs in C++ have been handled. Many more remain to be handled.
4862 See the various ChangeLog files (primarily in gdb and bfd) for details.
4864 * State of the MIPS world (in case you wondered):
4866 GDB can understand the symbol tables emitted by the compilers
4867 supplied by most vendors of MIPS-based machines, including DEC. These
4868 symbol tables are in a format that essentially nobody else uses.
4870 Some versions of gcc come with an assembler post-processor called
4871 mips-tfile. This program is required if you want to do source-level
4872 debugging of gcc-compiled programs. I believe FSF does not ship
4873 mips-tfile with gcc version 1, but it will eventually come with gcc
4876 Debugging of g++ output remains a problem. g++ version 1.xx does not
4877 really support it at all. (If you're lucky, you should be able to get
4878 line numbers and stack traces to work, but no parameters or local
4879 variables.) With some work it should be possible to improve the
4882 When gcc version 2 is released, you will have somewhat better luck.
4883 However, even then you will get confusing results for inheritance and
4886 We will eventually provide full debugging of g++ output on
4887 DECstations. This will probably involve some kind of stabs-in-ecoff
4888 encapulation, but the details have not been worked out yet.
4891 *** Changes in GDB-4.2:
4893 * Improved configuration
4895 Only one copy of `configure' exists now, and it is not self-modifying.
4896 Porting BFD is simpler.
4900 The `step' and `next' commands now only stop at the first instruction
4901 of a source line. This prevents the multiple stops that used to occur
4902 in switch statements, for-loops, etc. `Step' continues to stop if a
4903 function that has debugging information is called within the line.
4907 Lots of small bugs fixed. More remain.
4909 * New host supported (not target)
4911 Intel 386 PC clone running Mach i386-none-mach
4914 *** Changes in GDB-4.1:
4916 * Multiple source language support
4918 GDB now has internal scaffolding to handle several source languages.
4919 It determines the type of each source file from its filename extension,
4920 and will switch expression parsing and number formatting to match the
4921 language of the function in the currently selected stack frame.
4922 You can also specifically set the language to be used, with
4923 `set language c' or `set language modula-2'.
4927 GDB now has preliminary support for the GNU Modula-2 compiler,
4928 currently under development at the State University of New York at
4929 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4930 continue through the fall of 1991 and into 1992.
4932 Other Modula-2 compilers are currently not supported, and attempting to
4933 debug programs compiled with them will likely result in an error as the
4934 symbol table is read. Feel free to work on it, though!
4936 There are hooks in GDB for strict type checking and range checking,
4937 in the `Modula-2 philosophy', but they do not currently work.
4941 GDB can now write to executable and core files (e.g. patch
4942 a variable's value). You must turn this switch on, specify
4943 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4944 by assigning a new value to a variable. Modifications take
4947 * Automatic SunOS shared library reading
4949 When you run your program, GDB automatically determines where its
4950 shared libraries (if any) have been loaded, and reads their symbols.
4951 The `share' command is no longer needed. This also works when
4952 examining core files.
4956 You can specify the number of lines that the `list' command shows.
4959 * New machines supported (host and target)
4961 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4962 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4963 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4965 * New hosts supported (not targets)
4967 IBM RT/PC: romp-ibm-aix or rtpc
4969 * New targets supported (not hosts)
4971 AMD 29000 embedded with COFF a29k-none-coff
4972 AMD 29000 embedded with a.out a29k-none-aout
4973 Ultracomputer remote kernel debug a29k-nyu-kern
4975 * New remote interfaces
4981 *** Changes in GDB-4.0:
4985 Wide output is wrapped at good places to make the output more readable.
4987 Gdb now supports cross-debugging from a host machine of one type to a
4988 target machine of another type. Communication with the target system
4989 is over serial lines. The ``target'' command handles connecting to the
4990 remote system; the ``load'' command will download a program into the
4991 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4992 also supports debugging of realtime processes running under VxWorks,
4993 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4994 stub on the target system.
4996 New CPUs supported include the AMD 29000 and Intel 960.
4998 GDB now reads object files and symbol tables via a ``binary file''
4999 library, which allows a single copy of GDB to debug programs of multiple
5000 object file types such as a.out and coff.
5002 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5003 refcard.dvi and refcard.ps are available to format it).
5006 * Control-Variable user interface simplified
5008 All variables that control the operation of the debugger can be set
5009 by the ``set'' command, and displayed by the ``show'' command.
5011 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5012 ``Show prompt'' produces the response:
5013 Gdb's prompt is new-gdb=>.
5015 What follows are the NEW set commands. The command ``help set'' will
5016 print a complete list of old and new set commands. ``help set FOO''
5017 will give a longer description of the variable FOO. ``show'' will show
5018 all of the variable descriptions and their current settings.
5020 confirm on/off: Enables warning questions for operations that are
5021 hard to recover from, e.g. rerunning the program while
5022 it is already running. Default is ON.
5024 editing on/off: Enables EMACS style command line editing
5025 of input. Previous lines can be recalled with
5026 control-P, the current line can be edited with control-B,
5027 you can search for commands with control-R, etc.
5030 history filename NAME: NAME is where the gdb command history
5031 will be stored. The default is .gdb_history,
5032 or the value of the environment variable
5035 history size N: The size, in commands, of the command history. The
5036 default is 256, or the value of the environment variable
5039 history save on/off: If this value is set to ON, the history file will
5040 be saved after exiting gdb. If set to OFF, the
5041 file will not be saved. The default is OFF.
5043 history expansion on/off: If this value is set to ON, then csh-like
5044 history expansion will be performed on
5045 command line input. The default is OFF.
5047 radix N: Sets the default radix for input and output. It can be set
5048 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5049 in the current radix, so "set radix 10" is always a no-op.
5051 height N: This integer value is the number of lines on a page. Default
5052 is 24, the current `stty rows'' setting, or the ``li#''
5053 setting from the termcap entry matching the environment
5056 width N: This integer value is the number of characters on a line.
5057 Default is 80, the current `stty cols'' setting, or the ``co#''
5058 setting from the termcap entry matching the environment
5061 Note: ``set screensize'' is obsolete. Use ``set height'' and
5062 ``set width'' instead.
5064 print address on/off: Print memory addresses in various command displays,
5065 such as stack traces and structure values. Gdb looks
5066 more ``symbolic'' if you turn this off; it looks more
5067 ``machine level'' with it on. Default is ON.
5069 print array on/off: Prettyprint arrays. New convenient format! Default
5072 print demangle on/off: Print C++ symbols in "source" form if on,
5075 print asm-demangle on/off: Same, for assembler level printouts
5078 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5081 * Support for Epoch Environment.
5083 The epoch environment is a version of Emacs v18 with windowing. One
5084 new command, ``inspect'', is identical to ``print'', except that if you
5085 are running in the epoch environment, the value is printed in its own
5089 * Support for Shared Libraries
5091 GDB can now debug programs and core files that use SunOS shared libraries.
5092 Symbols from a shared library cannot be referenced
5093 before the shared library has been linked with the program (this
5094 happens after you type ``run'' and before the function main() is entered).
5095 At any time after this linking (including when examining core files
5096 from dynamically linked programs), gdb reads the symbols from each
5097 shared library when you type the ``sharedlibrary'' command.
5098 It can be abbreviated ``share''.
5100 sharedlibrary REGEXP: Load shared object library symbols for files
5101 matching a unix regular expression. No argument
5102 indicates to load symbols for all shared libraries.
5104 info sharedlibrary: Status of loaded shared libraries.
5109 A watchpoint stops execution of a program whenever the value of an
5110 expression changes. Checking for this slows down execution
5111 tremendously whenever you are in the scope of the expression, but is
5112 quite useful for catching tough ``bit-spreader'' or pointer misuse
5113 problems. Some machines such as the 386 have hardware for doing this
5114 more quickly, and future versions of gdb will use this hardware.
5116 watch EXP: Set a watchpoint (breakpoint) for an expression.
5118 info watchpoints: Information about your watchpoints.
5120 delete N: Deletes watchpoint number N (same as breakpoints).
5121 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5122 enable N: Re-enables watchpoint number N (same as breakpoints).
5125 * C++ multiple inheritance
5127 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5130 * C++ exception handling
5132 Gdb now supports limited C++ exception handling. Besides the existing
5133 ability to breakpoint on an exception handler, gdb can breakpoint on
5134 the raising of an exception (before the stack is peeled back to the
5137 catch FOO: If there is a FOO exception handler in the dynamic scope,
5138 set a breakpoint to catch exceptions which may be raised there.
5139 Multiple exceptions (``catch foo bar baz'') may be caught.
5141 info catch: Lists all exceptions which may be caught in the
5142 current stack frame.
5145 * Minor command changes
5147 The command ``call func (arg, arg, ...)'' now acts like the print
5148 command, except it does not print or save a value if the function's result
5149 is void. This is similar to dbx usage.
5151 The ``up'' and ``down'' commands now always print the frame they end up
5152 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5153 frames without printing.
5155 * New directory command
5157 'dir' now adds directories to the FRONT of the source search path.
5158 The path starts off empty. Source files that contain debug information
5159 about the directory in which they were compiled can be found even
5160 with an empty path; Sun CC and GCC include this information. If GDB can't
5161 find your source file in the current directory, type "dir .".
5163 * Configuring GDB for compilation
5165 For normal use, type ``./configure host''. See README or gdb.texinfo
5168 GDB now handles cross debugging. If you are remotely debugging between
5169 two different machines, type ``./configure host -target=targ''.
5170 Host is the machine where GDB will run; targ is the machine
5171 where the program that you are debugging will run.