1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
6 * The "info os" command on GNU/Linux can now display information on
7 several new classes of objects managed by the operating system:
8 "info os procgroups" lists process groups
9 "info os files" lists file descriptors
10 "info os sockets" lists internet-domain sockets
11 "info os shm" lists shared-memory regions
12 "info os semaphores" lists semaphores
13 "info os msg" lists message queues
14 "info os modules" lists loaded kernel modules
16 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
17 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
18 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
19 options and inspect the probe arguments using the new $_probe_arg family
20 of convenience variables. You can obtain more information about SystemTap
21 in <http://sourceware.org/systemtap/>.
23 * GDB now supports reversible debugging on ARM, it allows you to
24 debug basic ARM and THUMB instructions, and provides
25 record/replay support.
27 * The option "symbol-reloading" has been deleted as it is no longer used.
31 ** GDB commands implemented in Python can now be put in command class
34 ** The "maint set python print-stack on|off" is now deleted.
36 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
37 apply "flag enum"-style pretty-printing to any enum.
39 ** gdb.lookup_symbol can now work when there is no current frame.
41 ** gdb.Symbol now has a 'line' attribute, holding the line number in
42 the source at which the symbol was defined.
44 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
45 method 'value'. The former indicates whether the symbol needs a
46 frame in order to compute its value, and the latter computes the
49 ** A new method 'referenced_value' on gdb.Value objects which can
50 dereference pointer as well as C++ reference values.
52 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
53 which return the global and static blocks (as gdb.Block objects),
54 of the underlying symbol table, respectively.
56 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
57 object associated with a PC value.
59 * Go language support.
60 GDB now supports debugging programs written in the Go programming
63 * GDBserver now supports stdio connections.
64 E.g. (gdb) target remote | ssh myhost gdbserver - hello
66 * The binary "gdbtui" can no longer be built or installed.
67 Use "gdb -tui" instead.
69 * GDB will now print "flag" enums specially. A flag enum is one where
70 all the enumerator values have no bits in common when pairwise
71 "and"ed. When printing a value whose type is a flag enum, GDB will
72 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
73 (gdb) print (enum E) 3
76 * The filename part of a linespec will now match trailing components
77 of a source file name. For example, "break gcc/expr.c:1000" will
78 now set a breakpoint in build/gcc/expr.c, but not
81 * The "info proc" and "generate-core-file" commands will now also
82 work on remote targets connected to GDBserver on Linux.
84 * The command "info catch" has been removed. It has been disabled
87 * The "catch exception" and "catch assert" commands now accept
88 a condition at the end of the command, much like the "break"
89 command does. For instance:
91 (gdb) catch exception Constraint_Error if Barrier = True
93 Previously, it was possible to add a condition to such catchpoints,
94 but it had to be done as a second step, after the catchpoint had been
95 created, using the "condition" command.
97 * The "info static-tracepoint-marker" command will now also work on
98 native Linux targets with in-process agent.
100 * GDB can now set breakpoints on inlined functions.
102 * The .gdb_index section has been updated to include symbols for
103 inlined functions. GDB will ignore older .gdb_index sections by
104 default, which could cause symbol files to be loaded more slowly
105 until their .gdb_index sections can be recreated. The new option
106 --use-deprecated-index-sections will cause GDB to use any older
107 .gdb_index sections it finds. This will restore performance, but
108 the ability to set breakpoints on inlined functions will be lost
109 in symbol files with older .gdb_index sections.
111 * Ada support for GDB/MI Variable Objects has been added.
113 * GDB can now support 'breakpoint always-inserted mode' in 'record'
118 ** "catch load" and "catch unload" can be used to stop when a shared
119 library is loaded or unloaded, respectively.
121 ** "enable count" can be used to auto-disable a breakpoint after
124 ** "info vtbl" can be used to show the virtual method tables for
125 C++ and Java objects.
127 ** "explore" and its sub commands "explore value" and "explore type"
128 can be used to reccursively explore values and types of
129 expressions. These commands are available only if GDB is
130 configured with '--with-python'.
132 ** "info auto-load" shows status of all kinds of auto-loaded files,
133 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
134 sequences of commands files, "info auto-load python-scripts"
135 shows status of auto-loading Python script files,
136 "info auto-load local-gdbinit" shows status of loading init file
137 (.gdbinit) from current directory and "info auto-load libthread-db" shows
138 status of inferior specific thread debugging shared library loading.
140 ** "info auto-load-scripts", "set auto-load-scripts on|off"
141 and "show auto-load-scripts" commands have been deprecated, use their
142 "info auto-load python-scripts", "set auto-load python-scripts on|off"
143 and "show auto-load python-scripts" counterparts instead.
145 ** "dprintf location,format,args..." creates a dynamic printf, which
146 is basically a breakpoint that does a printf and immediately
147 resumes your program's execution, so it is like a printf that you
148 can insert dynamically at runtime instead of at compiletime.
150 ** "set print symbol"
152 Controls whether GDB attempts to display the symbol, if any,
153 corresponding to addresses it prints. This defaults to "on", but
154 you can set it to "off" to restore GDB's previous behavior.
158 Renesas RL78 rl78-*-elf
159 HP OpenVMS ia64 ia64-hp-openvms*
161 * GDBserver supports evaluation of breakpoint conditions. When
162 support is advertised by GDBserver, GDB may be told to send the
163 breakpoint conditions in bytecode form to GDBserver. GDBserver
164 will only report the breakpoint trigger to GDB when its condition
169 set breakpoint condition-evaluation
170 show breakpoint condition-evaluation
171 Control whether breakpoint conditions are evaluated by GDB ("host") or by
172 GDBserver ("target"). Default option "auto" chooses the most efficient
174 This option can improve debugger efficiency depending on the speed of the
178 Disable auto-loading globally.
181 Show auto-loading setting of all kinds of auto-loaded files.
183 set auto-load gdb-scripts on|off
184 show auto-load gdb-scripts
185 Control auto-loading of GDB canned sequences of commands files.
187 set auto-load python-scripts on|off
188 show auto-load python-scripts
189 Control auto-loading of Python script files.
191 set auto-load local-gdbinit on|off
192 show auto-load local-gdbinit
193 Control loading of init file (.gdbinit) from current directory.
195 set auto-load libthread-db on|off
196 show auto-load libthread-db
197 Control auto-loading of inferior specific thread debugging shared library.
199 set auto-load scripts-directory <dir1>[:<dir2>...]
200 show auto-load scripts-directory
201 Set a list of directories from which to load auto-loaded scripts.
202 Automatically loaded Python scripts and GDB scripts are located in one
203 of the directories listed by this option.
204 The delimiter (':' above) may differ according to the host platform.
206 set auto-load safe-path <dir1>[:<dir2>...]
207 show auto-load safe-path
208 Set a list of directories from which it is safe to auto-load files.
209 The delimiter (':' above) may differ according to the host platform.
211 set debug auto-load on|off
213 Control display of debugging info for auto-loading the files above.
215 set dprintf-style gdb|call
217 Control the way in which a dynamic printf is performed; "gdb" requests
218 a GDB printf command, while "call" causes dprintf to call a function
221 set dprintf-function <expr>
222 show dprintf-function
223 set dprintf-channel <expr>
225 Set the function and optional first argument to the call when using
226 the "call" style of dynamic printf.
228 * New configure options
231 Configure default value for the 'set auto-load scripts-directory'
232 setting above. It defaults to '$ddir/auto-load', $ddir representing
233 GDB's data directory (available via show data-directory).
235 --with-auto-load-safe-path
236 Configure default value for the 'set auto-load safe-path' setting
237 above. It defaults to the --with-auto-load-dir setting.
239 --without-auto-load-safe-path
240 Set 'set auto-load safe-path' to '/', effectively disabling this
245 z0/z1 conditional breakpoints extension
247 The z0/z1 breakpoint insertion packets have been extended to carry
248 a list of conditional expressions over to the remote stub depending on the
249 condition evaluation mode. The use of this extension can be controlled
250 via the "set remote conditional-breakpoints-packet" command.
254 Specify the signals which the remote stub may pass to the debugged
255 program without GDB involvement.
257 * New command line options
259 --init-command=FILE, -ix Like --command, -x but execute it
260 before loading inferior.
261 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
262 execute it before loading inferior.
264 *** Changes in GDB 7.4
266 * GDB now handles ambiguous linespecs more consistently; the existing
267 FILE:LINE support has been expanded to other types of linespecs. A
268 breakpoint will now be set on all matching locations in all
269 inferiors, and locations will be added or removed according to
272 * GDB now allows you to skip uninteresting functions and files when
273 stepping with the "skip function" and "skip file" commands.
275 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
276 and "show remote hardware-watchpoint-length-limit". These allows to
277 set or show the maximum length limit (in bytes) of a remote
278 target hardware watchpoint.
280 This allows e.g. to use "unlimited" hardware watchpoints with the
281 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
282 watchpoints are slower than real hardware watchpoints but are
283 significantly faster than gdb software watchpoints.
287 ** The register_pretty_printer function in module gdb.printing now takes
288 an optional `replace' argument. If True, the new printer replaces any
291 ** The "maint set python print-stack on|off" command has been
292 deprecated and will be deleted in GDB 7.5.
293 A new command: "set python print-stack none|full|message" has
294 replaced it. Additionally, the default for "print-stack" is
295 now "message", which just prints the error message without
298 ** A prompt substitution hook (prompt_hook) is now available to the
301 ** A new Python module, gdb.prompt has been added to the GDB Python
302 modules library. This module provides functionality for
303 escape sequences in prompts (used by set/show
304 extended-prompt). These escape sequences are replaced by their
307 ** Python commands and convenience-functions located in
308 'data-directory'/python/gdb/command and
309 'data-directory'/python/gdb/function are now automatically loaded
312 ** Blocks now provide four new attributes. global_block and
313 static_block will return the global and static blocks
314 respectively. is_static and is_global are boolean attributes
315 that indicate if the block is one of those two types.
317 ** Symbols now provide the "type" attribute, the type of the symbol.
319 ** The "gdb.breakpoint" function has been deprecated in favor of
322 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
323 of a function. This class is based on the "finish" command
324 available in the CLI.
326 ** Type objects for struct and union types now allow access to
327 the fields using standard Python dictionary (mapping) methods.
328 For example, "some_type['myfield']" now works, as does
331 ** A new event "gdb.new_objfile" has been added, triggered by loading a
334 ** A new function, "deep_items" has been added to the gdb.types
335 module in the GDB Python modules library. This function returns
336 an iterator over the fields of a struct or union type. Unlike
337 the standard Python "iteritems" method, it will recursively traverse
338 any anonymous fields.
342 ** "*stopped" events can report several new "reason"s, such as
345 ** Breakpoint changes are now notified using new async records, like
346 "=breakpoint-modified".
348 ** New command -ada-task-info.
350 * libthread-db-search-path now supports two special values: $sdir and $pdir.
351 $sdir specifies the default system locations of shared libraries.
352 $pdir specifies the directory where the libpthread used by the application
355 GDB no longer looks in $sdir and $pdir after it has searched the directories
356 mentioned in libthread-db-search-path. If you want to search those
357 directories, they must be specified in libthread-db-search-path.
358 The default value of libthread-db-search-path on GNU/Linux and Solaris
359 systems is now "$sdir:$pdir".
361 $pdir is not supported by gdbserver, it is currently ignored.
362 $sdir is supported by gdbserver.
364 * New configure option --with-iconv-bin.
365 When using the internationalization support like the one in the GNU C
366 library, GDB will invoke the "iconv" program to get a list of supported
367 character sets. If this program lives in a non-standard location, one can
368 use this option to specify where to find it.
370 * When natively debugging programs on PowerPC BookE processors running
371 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
372 watchpoints, which specify a mask in addition to an address to watch.
373 The mask specifies that some bits of an address (the bits which are
374 reset in the mask) should be ignored when matching the address accessed
375 by the inferior against the watchpoint address. See the "PowerPC Embedded"
376 section in the user manual for more details.
378 * The new option --once causes GDBserver to stop listening for connections once
379 the first connection is made. The listening port used by GDBserver will
380 become available after that.
382 * New commands "info macros" and "alias" have been added.
384 * New function parameters suffix @entry specifies value of function parameter
385 at the time the function got called. Entry values are available only since
391 "!" is now an alias of the "shell" command.
392 Note that no space is needed between "!" and SHELL COMMAND.
396 watch EXPRESSION mask MASK_VALUE
397 The watch command now supports the mask argument which allows creation
398 of masked watchpoints, if the current architecture supports this feature.
400 info auto-load-scripts [REGEXP]
401 This command was formerly named "maintenance print section-scripts".
402 It is now generally useful and is no longer a maintenance-only command.
404 info macro [-all] [--] MACRO
405 The info macro command has new options `-all' and `--'. The first for
406 printing all definitions of a macro. The second for explicitly specifying
407 the end of arguments and the beginning of the macro name in case the macro
408 name starts with a hyphen.
410 collect[/s] EXPRESSIONS
411 The tracepoint collect command now takes an optional modifier "/s"
412 that directs it to dereference pointer-to-character types and
413 collect the bytes of memory up to a zero byte. The behavior is
414 similar to what you see when you use the regular print command on a
415 string. An optional integer following the "/s" sets a bound on the
416 number of bytes that will be collected.
419 The trace start command now interprets any supplied arguments as a
420 note to be recorded with the trace run, with an effect similar to
421 setting the variable trace-notes.
424 The trace stop command now interprets any arguments as a note to be
425 mentioned along with the tstatus report that the trace was stopped
426 with a command. The effect is similar to setting the variable
429 * Tracepoints can now be enabled and disabled at any time after a trace
430 experiment has been started using the standard "enable" and "disable"
431 commands. It is now possible to start a trace experiment with no enabled
432 tracepoints; GDB will display a warning, but will allow the experiment to
433 begin, assuming that tracepoints will be enabled as needed while the trace
436 * Fast tracepoints on 32-bit x86-architectures can now be placed at
437 locations with 4-byte instructions, when they were previously
438 limited to locations with instructions of 5 bytes or longer.
444 Set the GDB prompt, and allow escape sequences to be inserted to
445 display miscellaneous information (see 'help set extended-prompt'
446 for the list of sequences). This prompt (and any information
447 accessed through the escape sequences) is updated every time the
450 set print entry-values (both|compact|default|if-needed|no|only|preferred)
451 show print entry-values
452 Set printing of frame argument values at function entry. In some cases
453 GDB can determine the value of function argument which was passed by the
454 function caller, even if the value was modified inside the called function.
456 set debug entry-values
457 show debug entry-values
458 Control display of debugging info for determining frame argument values at
459 function entry and virtual tail call frames.
461 set basenames-may-differ
462 show basenames-may-differ
463 Set whether a source file may have multiple base names.
464 (A "base name" is the name of a file with the directory part removed.
465 Example: The base name of "/home/user/hello.c" is "hello.c".)
466 If set, GDB will canonicalize file names (e.g., expand symlinks)
467 before comparing them. Canonicalization is an expensive operation,
468 but it allows the same file be known by more than one base name.
469 If not set (the default), all source files are assumed to have just
470 one base name, and gdb will do file name comparisons more efficiently.
476 Set a user name and notes for the current and any future trace runs.
477 This is useful for long-running and/or disconnected traces, to
478 inform others (or yourself) as to who is running the trace, supply
479 contact information, or otherwise explain what is going on.
482 show trace-stop-notes
483 Set a note attached to the trace run, that is displayed when the
484 trace has been stopped by a tstop command. This is useful for
485 instance as an explanation, if you are stopping a trace run that was
486 started by someone else.
492 Dynamically enable a tracepoint in a started trace experiment.
496 Dynamically disable a tracepoint in a started trace experiment.
500 Set the user and notes of the trace run.
504 Query the current status of a tracepoint.
508 Query the minimum length of instruction at which a fast tracepoint may
511 * Dcache size (number of lines) and line-size are now runtime-configurable
512 via "set dcache line" and "set dcache line-size" commands.
516 Texas Instruments TMS320C6x tic6x-*-*
520 Renesas RL78 rl78-*-elf
522 *** Changes in GDB 7.3.1
524 * The build failure for NetBSD and OpenBSD targets have now been fixed.
526 *** Changes in GDB 7.3
528 * GDB has a new command: "thread find [REGEXP]".
529 It finds the thread id whose name, target id, or thread extra info
530 matches the given regular expression.
532 * The "catch syscall" command now works on mips*-linux* targets.
534 * The -data-disassemble MI command now supports modes 2 and 3 for
535 dumping the instruction opcodes.
537 * New command line options
539 -data-directory DIR Specify DIR as the "data-directory".
540 This is mostly for testing purposes.
542 * The "maint set python auto-load on|off" command has been renamed to
543 "set auto-load-scripts on|off".
545 * GDB has a new command: "set directories".
546 It is like the "dir" command except that it replaces the
547 source path list instead of augmenting it.
549 * GDB now understands thread names.
551 On GNU/Linux, "info threads" will display the thread name as set by
552 prctl or pthread_setname_np.
554 There is also a new command, "thread name", which can be used to
555 assign a name internally for GDB to display.
558 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
559 has been integrated into GDB.
563 ** The function gdb.Write now accepts an optional keyword 'stream'.
564 This keyword, when provided, will direct the output to either
565 stdout, stderr, or GDB's logging output.
567 ** Parameters can now be be sub-classed in Python, and in particular
568 you may implement the get_set_doc and get_show_doc functions.
569 This improves how Parameter set/show documentation is processed
570 and allows for more dynamic content.
572 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
573 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
574 have an is_valid method.
576 ** Breakpoints can now be sub-classed in Python, and in particular
577 you may implement a 'stop' function that is executed each time
578 the inferior reaches that breakpoint.
580 ** New function gdb.lookup_global_symbol looks up a global symbol.
582 ** GDB values in Python are now callable if the value represents a
583 function. For example, if 'some_value' represents a function that
584 takes two integer parameters and returns a value, you can call
585 that function like so:
587 result = some_value (10,20)
589 ** Module gdb.types has been added.
590 It contains a collection of utilities for working with gdb.Types objects:
591 get_basic_type, has_field, make_enum_dict.
593 ** Module gdb.printing has been added.
594 It contains utilities for writing and registering pretty-printers.
595 New classes: PrettyPrinter, SubPrettyPrinter,
596 RegexpCollectionPrettyPrinter.
597 New function: register_pretty_printer.
599 ** New commands "info pretty-printers", "enable pretty-printer" and
600 "disable pretty-printer" have been added.
602 ** gdb.parameter("directories") is now available.
604 ** New function gdb.newest_frame returns the newest frame in the
607 ** The gdb.InferiorThread class has a new "name" attribute. This
608 holds the thread's name.
610 ** Python Support for Inferior events.
611 Python scripts can add observers to be notified of events
612 occurring in the process being debugged.
613 The following events are currently supported:
614 - gdb.events.cont Continue event.
615 - gdb.events.exited Inferior exited event.
616 - gdb.events.stop Signal received, and Breakpoint hit events.
620 ** GDB now puts template parameters in scope when debugging in an
621 instantiation. For example, if you have:
623 template<int X> int func (void) { return X; }
625 then if you step into func<5>, "print X" will show "5". This
626 feature requires proper debuginfo support from the compiler; it
627 was added to GCC 4.5.
629 ** The motion commands "next", "finish", "until", and "advance" now
630 work better when exceptions are thrown. In particular, GDB will
631 no longer lose control of the inferior; instead, the GDB will
632 stop the inferior at the point at which the exception is caught.
633 This functionality requires a change in the exception handling
634 code that was introduced in GCC 4.5.
636 * GDB now follows GCC's rules on accessing volatile objects when
637 reading or writing target state during expression evaluation.
638 One notable difference to prior behavior is that "print x = 0"
639 no longer generates a read of x; the value of the assignment is
640 now always taken directly from the value being assigned.
642 * GDB now has some support for using labels in the program's source in
643 linespecs. For instance, you can use "advance label" to continue
644 execution to a label.
646 * GDB now has support for reading and writing a new .gdb_index
647 section. This section holds a fast index of DWARF debugging
648 information and can be used to greatly speed up GDB startup and
649 operation. See the documentation for `save gdb-index' for details.
651 * The "watch" command now accepts an optional "-location" argument.
652 When used, this causes GDB to watch the memory referred to by the
653 expression. Such a watchpoint is never deleted due to it going out
656 * GDB now supports thread debugging of core dumps on GNU/Linux.
658 GDB now activates thread debugging using the libthread_db library
659 when debugging GNU/Linux core dumps, similarly to when debugging
660 live processes. As a result, when debugging a core dump file, GDB
661 is now able to display pthread_t ids of threads. For example, "info
662 threads" shows the same output as when debugging the process when it
663 was live. In earlier releases, you'd see something like this:
666 * 1 LWP 6780 main () at main.c:10
668 While now you see this:
671 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
673 It is also now possible to inspect TLS variables when debugging core
676 When debugging a core dump generated on a machine other than the one
677 used to run GDB, you may need to point GDB at the correct
678 libthread_db library with the "set libthread-db-search-path"
679 command. See the user manual for more details on this command.
681 * When natively debugging programs on PowerPC BookE processors running
682 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
683 which stop execution of the inferior whenever it executes an instruction
684 at any address within the specified range. See the "PowerPC Embedded"
685 section in the user manual for more details.
687 * New features in the GDB remote stub, GDBserver
689 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
690 and i686 LynxOS (version 5.x).
692 ** GDBserver is now supported on Blackfin Linux.
694 * New native configurations
696 ia64 HP-UX ia64-*-hpux*
700 Analog Devices, Inc. Blackfin Processor bfin-*
702 * Ada task switching is now supported on sparc-elf targets when
703 debugging a program using the Ravenscar Profile. For more information,
704 see the "Tasking Support when using the Ravenscar Profile" section
705 in the GDB user manual.
707 * Guile support was removed.
709 * New features in the GNU simulator
711 ** The --map-info flag lists all known core mappings.
713 ** CFI flashes may be simulated via the "cfi" device.
715 *** Changes in GDB 7.2
717 * Shared library support for remote targets by default
719 When GDB is configured for a generic, non-OS specific target, like
720 for example, --target=arm-eabi or one of the many *-*-elf targets,
721 GDB now queries remote stubs for loaded shared libraries using the
722 `qXfer:libraries:read' packet. Previously, shared library support
723 was always disabled for such configurations.
727 ** Argument Dependent Lookup (ADL)
729 In C++ ADL lookup directs function search to the namespaces of its
730 arguments even if the namespace has not been imported.
740 Here the compiler will search for `foo' in the namespace of 'b'
741 and find A::foo. GDB now supports this. This construct is commonly
742 used in the Standard Template Library for operators.
744 ** Improved User Defined Operator Support
746 In addition to member operators, GDB now supports lookup of operators
747 defined in a namespace and imported with a `using' directive, operators
748 defined in the global scope, operators imported implicitly from an
749 anonymous namespace, and the ADL operators mentioned in the previous
751 GDB now also supports proper overload resolution for all the previously
752 mentioned flavors of operators.
754 ** static const class members
756 Printing of static const class members that are initialized in the
757 class definition has been fixed.
759 * Windows Thread Information Block access.
761 On Windows targets, GDB now supports displaying the Windows Thread
762 Information Block (TIB) structure. This structure is visible either
763 by using the new command `info w32 thread-information-block' or, by
764 dereferencing the new convenience variable named `$_tlb', a
765 thread-specific pointer to the TIB. This feature is also supported
766 when remote debugging using GDBserver.
770 Static tracepoints are calls in the user program into a tracing
771 library. One such library is a port of the LTTng kernel tracer to
772 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
773 When debugging with GDBserver, GDB now supports combining the GDB
774 tracepoint machinery with such libraries. For example: the user can
775 use GDB to probe a static tracepoint marker (a call from the user
776 program into the tracing library) with the new "strace" command (see
777 "New commands" below). This creates a "static tracepoint" in the
778 breakpoint list, that can be manipulated with the same feature set
779 as fast and regular tracepoints. E.g., collect registers, local and
780 global variables, collect trace state variables, and define
781 tracepoint conditions. In addition, the user can collect extra
782 static tracepoint marker specific data, by collecting the new
783 $_sdata internal variable. When analyzing the trace buffer, you can
784 inspect $_sdata like any other variable available to GDB. For more
785 information, see the "Tracepoints" chapter in GDB user manual. New
786 remote packets have been defined to support static tracepoints, see
787 the "New remote packets" section below.
789 * Better reconstruction of tracepoints after disconnected tracing
791 GDB will attempt to download the original source form of tracepoint
792 definitions when starting a trace run, and then will upload these
793 upon reconnection to the target, resulting in a more accurate
794 reconstruction of the tracepoints that are in use on the target.
798 You can now exercise direct control over the ways that GDB can
799 affect your program. For instance, you can disallow the setting of
800 breakpoints, so that the program can run continuously (assuming
801 non-stop mode). In addition, the "observer" variable is available
802 to switch all of the different controls; in observer mode, GDB
803 cannot affect the target's behavior at all, which is useful for
804 tasks like diagnosing live systems in the field.
806 * The new convenience variable $_thread holds the number of the
813 Return the address of the Windows Thread Information Block of a given thread.
817 In response to several of the tracepoint packets, the target may now
818 also respond with a number of intermediate `qRelocInsn' request
819 packets before the final result packet, to have GDB handle
820 relocating an instruction to execute at a different address. This
821 is particularly useful for stubs that support fast tracepoints. GDB
822 reports support for this feature in the qSupported packet.
826 List static tracepoint markers in the target program.
830 List static tracepoint markers at a given address in the target
833 qXfer:statictrace:read
835 Read the static trace data collected (by a `collect $_sdata'
836 tracepoint action). The remote stub reports support for this packet
837 to gdb's qSupported query.
841 Send the current settings of GDB's permission flags.
845 Send part of the source (textual) form of a tracepoint definition,
846 which includes location, conditional, and action list.
848 * The source command now accepts a -s option to force searching for the
849 script in the source search path even if the script name specifies
852 * New features in the GDB remote stub, GDBserver
854 - GDBserver now support tracepoints (including fast tracepoints, and
855 static tracepoints). The feature is currently supported by the
856 i386-linux and amd64-linux builds. See the "Tracepoints support
857 in gdbserver" section in the manual for more information.
859 GDBserver JIT compiles the tracepoint's conditional agent
860 expression bytecode into native code whenever possible for low
861 overhead dynamic tracepoints conditionals. For such tracepoints,
862 an expression that examines program state is evaluated when the
863 tracepoint is reached, in order to determine whether to capture
864 trace data. If the condition is simple and false, processing the
865 tracepoint finishes very quickly and no data is gathered.
867 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
868 for static tracepoints support.
870 - GDBserver now supports x86_64 Windows 64-bit debugging.
872 * GDB now sends xmlRegisters= in qSupported packet to indicate that
873 it understands register description.
875 * The --batch flag now disables pagination and queries.
877 * X86 general purpose registers
879 GDB now supports reading/writing byte, word and double-word x86
880 general purpose registers directly. This means you can use, say,
881 $ah or $ax to refer, respectively, to the byte register AH and
882 16-bit word register AX that are actually portions of the 32-bit
883 register EAX or 64-bit register RAX.
885 * The `commands' command now accepts a range of breakpoints to modify.
886 A plain `commands' following a command that creates multiple
887 breakpoints affects all the breakpoints set by that command. This
888 applies to breakpoints set by `rbreak', and also applies when a
889 single `break' command creates multiple breakpoints (e.g.,
890 breakpoints on overloaded c++ functions).
892 * The `rbreak' command now accepts a filename specification as part of
893 its argument, limiting the functions selected by the regex to those
894 in the specified file.
896 * Support for remote debugging Windows and SymbianOS shared libraries
897 from Unix hosts has been improved. Non Windows GDB builds now can
898 understand target reported file names that follow MS-DOS based file
899 system semantics, such as file names that include drive letters and
900 use the backslash character as directory separator. This makes it
901 possible to transparently use the "set sysroot" and "set
902 solib-search-path" on Unix hosts to point as host copies of the
903 target's shared libraries. See the new command "set
904 target-file-system-kind" described below, and the "Commands to
905 specify files" section in the user manual for more information.
909 eval template, expressions...
910 Convert the values of one or more expressions under the control
911 of the string template to a command line, and call it.
913 set target-file-system-kind unix|dos-based|auto
914 show target-file-system-kind
915 Set or show the assumed file system kind for target reported file
918 save breakpoints <filename>
919 Save all current breakpoint definitions to a file suitable for use
920 in a later debugging session. To read the saved breakpoint
921 definitions, use the `source' command.
923 `save tracepoints' is a new alias for `save-tracepoints'. The latter
926 info static-tracepoint-markers
927 Display information about static tracepoint markers in the target.
929 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
930 Define a static tracepoint by probing a marker at the given
931 function, line, address, or marker ID.
935 Enable and disable observer mode.
937 set may-write-registers on|off
938 set may-write-memory on|off
939 set may-insert-breakpoints on|off
940 set may-insert-tracepoints on|off
941 set may-insert-fast-tracepoints on|off
942 set may-interrupt on|off
943 Set individual permissions for GDB effects on the target. Note that
944 some of these settings can have undesirable or surprising
945 consequences, particularly when changed in the middle of a session.
946 For instance, disabling the writing of memory can prevent
947 breakpoints from being inserted, cause single-stepping to fail, or
948 even crash your program, if you disable after breakpoints have been
949 inserted. However, GDB should not crash.
951 set record memory-query on|off
952 show record memory-query
953 Control whether to stop the inferior if memory changes caused
954 by an instruction cannot be recorded.
959 The disassemble command now supports "start,+length" form of two arguments.
963 ** GDB now provides a new directory location, called the python directory,
964 where Python scripts written for GDB can be installed. The location
965 of that directory is <data-directory>/python, where <data-directory>
966 is the GDB data directory. For more details, see section `Scripting
967 GDB using Python' in the manual.
969 ** The GDB Python API now has access to breakpoints, symbols, symbol
970 tables, program spaces, inferiors, threads and frame's code blocks.
971 Additionally, GDB Parameters can now be created from the API, and
972 manipulated via set/show in the CLI.
974 ** New functions gdb.target_charset, gdb.target_wide_charset,
975 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
977 ** New exception gdb.GdbError.
979 ** Pretty-printers are now also looked up in the current program space.
981 ** Pretty-printers can now be individually enabled and disabled.
983 ** GDB now looks for names of Python scripts to auto-load in a
984 special section named `.debug_gdb_scripts', in addition to looking
985 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
987 * Tracepoint actions were unified with breakpoint commands. In particular,
988 there are no longer differences in "info break" output for breakpoints and
989 tracepoints and the "commands" command can be used for both tracepoints and
994 ARM Symbian arm*-*-symbianelf*
996 * D language support.
997 GDB now supports debugging programs written in the D programming
1000 * GDB now supports the extended ptrace interface for PowerPC which is
1001 available since Linux kernel version 2.6.34. This automatically enables
1002 any hardware breakpoints and additional hardware watchpoints available in
1003 the processor. The old ptrace interface exposes just one hardware
1004 watchpoint and no hardware breakpoints.
1006 * GDB is now able to use the Data Value Compare (DVC) register available on
1007 embedded PowerPC processors to implement in hardware simple watchpoint
1008 conditions of the form:
1010 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1012 This works in native GDB running on Linux kernels with the extended ptrace
1013 interface mentioned above.
1015 *** Changes in GDB 7.1
1019 ** Namespace Support
1021 GDB now supports importing of namespaces in C++. This enables the
1022 user to inspect variables from imported namespaces. Support for
1023 namepace aliasing has also been added. So, if a namespace is
1024 aliased in the current scope (e.g. namepace C=A; ) the user can
1025 print variables using the alias (e.g. (gdb) print C::x).
1029 All known bugs relating to the printing of virtual base class were
1030 fixed. It is now possible to call overloaded static methods using a
1035 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1036 and reinterpret_cast<> are now handled by the C++ expression parser.
1040 Xilinx MicroBlaze microblaze-*-*
1045 Xilinx MicroBlaze microblaze
1048 * Multi-program debugging.
1050 GDB now has support for multi-program (a.k.a. multi-executable or
1051 multi-exec) debugging. This allows for debugging multiple inferiors
1052 simultaneously each running a different program under the same GDB
1053 session. See "Debugging Multiple Inferiors and Programs" in the
1054 manual for more information. This implied some user visible changes
1055 in the multi-inferior support. For example, "info inferiors" now
1056 lists inferiors that are not running yet or that have exited
1057 already. See also "New commands" and "New options" below.
1059 * New tracing features
1061 GDB's tracepoint facility now includes several new features:
1063 ** Trace state variables
1065 GDB tracepoints now include support for trace state variables, which
1066 are variables managed by the target agent during a tracing
1067 experiment. They are useful for tracepoints that trigger each
1068 other, so for instance one tracepoint can count hits in a variable,
1069 and then a second tracepoint has a condition that is true when the
1070 count reaches a particular value. Trace state variables share the
1071 $-syntax of GDB convenience variables, and can appear in both
1072 tracepoint actions and condition expressions. Use the "tvariable"
1073 command to create, and "info tvariables" to view; see "Trace State
1074 Variables" in the manual for more detail.
1078 GDB now includes an option for defining fast tracepoints, which
1079 targets may implement more efficiently, such as by installing a jump
1080 into the target agent rather than a trap instruction. The resulting
1081 speedup can be by two orders of magnitude or more, although the
1082 tradeoff is that some program locations on some target architectures
1083 might not allow fast tracepoint installation, for instance if the
1084 instruction to be replaced is shorter than the jump. To request a
1085 fast tracepoint, use the "ftrace" command, with syntax identical to
1086 the regular trace command.
1088 ** Disconnected tracing
1090 It is now possible to detach GDB from the target while it is running
1091 a trace experiment, then reconnect later to see how the experiment
1092 is going. In addition, a new variable disconnected-tracing lets you
1093 tell the target agent whether to continue running a trace if the
1094 connection is lost unexpectedly.
1098 GDB now has the ability to save the trace buffer into a file, and
1099 then use that file as a target, similarly to you can do with
1100 corefiles. You can select trace frames, print data that was
1101 collected in them, and use tstatus to display the state of the
1102 tracing run at the moment that it was saved. To create a trace
1103 file, use "tsave <filename>", and to use it, do "target tfile
1106 ** Circular trace buffer
1108 You can ask the target agent to handle the trace buffer as a
1109 circular buffer, discarding the oldest trace frames to make room for
1110 newer ones, by setting circular-trace-buffer to on. This feature may
1111 not be available for all target agents.
1116 The disassemble command, when invoked with two arguments, now requires
1117 the arguments to be comma-separated.
1120 The info variables command now displays variable definitions. Files
1121 which only declare a variable are not shown.
1124 The source command is now capable of sourcing Python scripts.
1125 This feature is dependent on the debugger being build with Python
1128 Related to this enhancement is also the introduction of a new command
1129 "set script-extension" (see below).
1131 * New commands (for set/show, see "New options" below)
1133 record save [<FILENAME>]
1134 Save a file (in core file format) containing the process record
1135 execution log for replay debugging at a later time.
1137 record restore <FILENAME>
1138 Restore the process record execution log that was saved at an
1139 earlier time, for replay debugging.
1141 add-inferior [-copies <N>] [-exec <FILENAME>]
1144 clone-inferior [-copies <N>] [ID]
1145 Make a new inferior ready to execute the same program another
1146 inferior has loaded.
1151 maint info program-spaces
1152 List the program spaces loaded into GDB.
1154 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1155 show remote interrupt-sequence
1156 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1157 as the sequence to the remote target in order to interrupt the execution.
1158 Ctrl-C is a default. Some system prefers BREAK which is high level of
1159 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1160 Magic SysRq g. It is BREAK signal and character 'g'.
1162 set remote interrupt-on-connect [on | off]
1163 show remote interrupt-on-connect
1164 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1165 remote target when gdb connects to it. This is needed when you debug
1168 set remotebreak [on | off]
1170 Deprecated. Use "set/show remote interrupt-sequence" instead.
1172 tvariable $NAME [ = EXP ]
1173 Create or modify a trace state variable.
1176 List trace state variables and their values.
1178 delete tvariable $NAME ...
1179 Delete one or more trace state variables.
1182 Evaluate the given expressions without collecting anything into the
1183 trace buffer. (Valid in tracepoint actions only.)
1185 ftrace FN / FILE:LINE / *ADDR
1186 Define a fast tracepoint at the given function, line, or address.
1188 * New expression syntax
1190 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1191 GDB now parses 0b101010 identically with 42.
1195 set follow-exec-mode new|same
1196 show follow-exec-mode
1197 Control whether GDB reuses the same inferior across an exec call or
1198 creates a new one. This is useful to be able to restart the old
1199 executable after the inferior having done an exec call.
1201 set default-collect EXPR, ...
1202 show default-collect
1203 Define a list of expressions to be collected at each tracepoint.
1204 This is a useful way to ensure essential items are not overlooked,
1205 such as registers or a critical global variable.
1207 set disconnected-tracing
1208 show disconnected-tracing
1209 If set to 1, the target is instructed to continue tracing if it
1210 loses its connection to GDB. If 0, the target is to stop tracing
1213 set circular-trace-buffer
1214 show circular-trace-buffer
1215 If set to on, the target is instructed to use a circular trace buffer
1216 and discard the oldest trace frames instead of stopping the trace due
1217 to a full trace buffer. If set to off, the trace stops when the buffer
1218 fills up. Some targets may not support this.
1220 set script-extension off|soft|strict
1221 show script-extension
1222 If set to "off", the debugger does not perform any script language
1223 recognition, and all sourced files are assumed to be GDB scripts.
1224 If set to "soft" (the default), files are sourced according to
1225 filename extension, falling back to GDB scripts if the first
1227 If set to "strict", files are sourced according to filename extension.
1229 set ada trust-PAD-over-XVS on|off
1230 show ada trust-PAD-over-XVS
1231 If off, activate a workaround against a bug in the debugging information
1232 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1233 the GCC sources for more information about the GNAT encoding and
1234 PAD types in particular). It is always safe to set this option to
1235 off, but this introduces a slight performance penalty. The default
1238 * Python API Improvements
1240 ** GDB provides the new class gdb.LazyString. This is useful in
1241 some pretty-printing cases. The new method gdb.Value.lazy_string
1242 provides a simple way to create objects of this type.
1244 ** The fields returned by gdb.Type.fields now have an
1245 `is_base_class' attribute.
1247 ** The new method gdb.Type.range returns the range of an array type.
1249 ** The new method gdb.parse_and_eval can be used to parse and
1250 evaluate an expression.
1252 * New remote packets
1255 Define a trace state variable.
1258 Get the current value of a trace state variable.
1261 Set desired tracing behavior upon disconnection.
1264 Set the trace buffer to be linear or circular.
1267 Get data about the tracepoints currently in use.
1271 Process record now works correctly with hardware watchpoints.
1273 Multiple bug fixes have been made to the mips-irix port, making it
1274 much more reliable. In particular:
1275 - Debugging threaded applications is now possible again. Previously,
1276 GDB would hang while starting the program, or while waiting for
1277 the program to stop at a breakpoint.
1278 - Attaching to a running process no longer hangs.
1279 - An error occurring while loading a core file has been fixed.
1280 - Changing the value of the PC register now works again. This fixes
1281 problems observed when using the "jump" command, or when calling
1282 a function from GDB, or even when assigning a new value to $pc.
1283 - With the "finish" and "return" commands, the return value for functions
1284 returning a small array is now correctly printed.
1285 - It is now possible to break on shared library code which gets executed
1286 during a shared library init phase (code executed while executing
1287 their .init section). Previously, the breakpoint would have no effect.
1288 - GDB is now able to backtrace through the signal handler for
1289 non-threaded programs.
1291 PIE (Position Independent Executable) programs debugging is now supported.
1292 This includes debugging execution of PIC (Position Independent Code) shared
1293 libraries although for that, it should be possible to run such libraries as an
1296 *** Changes in GDB 7.0
1298 * GDB now has an interface for JIT compilation. Applications that
1299 dynamically generate code can create symbol files in memory and register
1300 them with GDB. For users, the feature should work transparently, and
1301 for JIT developers, the interface is documented in the GDB manual in the
1302 "JIT Compilation Interface" chapter.
1304 * Tracepoints may now be conditional. The syntax is as for
1305 breakpoints; either an "if" clause appended to the "trace" command,
1306 or the "condition" command is available. GDB sends the condition to
1307 the target for evaluation using the same bytecode format as is used
1308 for tracepoint actions.
1310 * The disassemble command now supports: an optional /r modifier, print the
1311 raw instructions in hex as well as in symbolic form, and an optional /m
1312 modifier to print mixed source+assembly.
1314 * Process record and replay
1316 In a architecture environment that supports ``process record and
1317 replay'', ``process record and replay'' target can record a log of
1318 the process execution, and replay it with both forward and reverse
1321 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1322 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1323 set execution-direction {forward|reverse}, for targets that support
1326 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1327 feature is available with a native GDB running on kernel version
1330 * GDB now has support for multi-byte and wide character sets on the
1331 target. Strings whose character type is wchar_t, char16_t, or
1332 char32_t are now correctly printed. GDB supports wide- and unicode-
1333 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1334 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1335 `printf'. This feature requires iconv to work properly; if your
1336 system does not have a working iconv, GDB can use GNU libiconv. See
1337 the installation instructions for more information.
1339 * GDB now supports automatic retrieval of shared library files from
1340 remote targets. To use this feature, specify a system root that begins
1341 with the `remote:' prefix, either via the `set sysroot' command or via
1342 the `--with-sysroot' configure-time option.
1344 * "info sharedlibrary" now takes an optional regex of libraries to show,
1345 and it now reports if a shared library has no debugging information.
1347 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1348 now complete on file names.
1350 * When completing in expressions, gdb will attempt to limit
1351 completions to allowable structure or union fields, where appropriate.
1352 For instance, consider:
1354 # struct example { int f1; double f2; };
1355 # struct example variable;
1358 If the user types TAB at the end of this command line, the available
1359 completions will be "f1" and "f2".
1361 * Inlined functions are now supported. They show up in backtraces, and
1362 the "step", "next", and "finish" commands handle them automatically.
1364 * GDB now supports the token-splicing (##) and stringification (#)
1365 operators when expanding macros. It also supports variable-arity
1368 * GDB now supports inspecting extra signal information, exported by
1369 the new $_siginfo convenience variable. The feature is currently
1370 implemented on linux ARM, i386 and amd64.
1372 * GDB can now display the VFP floating point registers and NEON vector
1373 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1374 can provide these registers (requires Linux 2.6.30 or later). Remote
1375 and simulator targets may also provide them.
1377 * New remote packets
1380 Search memory for a sequence of bytes.
1383 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1384 operation over reliable transport links. Use of this packet is
1385 controlled by the `set remote noack-packet' command.
1388 Kill the process with the specified process ID. Use this in preference
1389 to `k' when multiprocess protocol extensions are supported.
1392 Obtains additional operating system information
1396 Read or write additional signal information.
1398 * Removed remote protocol undocumented extension
1400 An undocumented extension to the remote protocol's `S' stop reply
1401 packet that permited the stub to pass a process id was removed.
1402 Remote servers should use the `T' stop reply packet instead.
1404 * GDB now supports multiple function calling conventions according to the
1405 DWARF-2 DW_AT_calling_convention function attribute.
1407 * The SH target utilizes the aforementioned change to distinguish between gcc
1408 and Renesas calling convention. It also adds the new CLI commands
1409 `set/show sh calling-convention'.
1411 * GDB can now read compressed debug sections, as produced by GNU gold
1412 with the --compress-debug-sections=zlib flag.
1414 * 64-bit core files are now supported on AIX.
1416 * Thread switching is now supported on Tru64.
1418 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1419 which will be allocated using malloc later in program execution.
1421 * The qXfer:libraries:read remote procotol packet now allows passing a
1422 list of section offsets.
1424 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1425 conditions handling signals delivered during attach or thread creation
1426 have also been fixed.
1428 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1429 From the user's standpoint, all unqualified instances of True and False
1430 are treated as the standard definitions, regardless of context.
1432 * GDB now parses C++ symbol and type names more flexibly. For
1435 template<typename T> class C { };
1438 GDB will now correctly handle all of:
1440 ptype C<char const *>
1441 ptype C<char const*>
1442 ptype C<const char *>
1443 ptype C<const char*>
1445 * New features in the GDB remote stub, gdbserver
1447 - The "--wrapper" command-line argument tells gdbserver to use a
1448 wrapper program to launch programs for debugging.
1450 - On PowerPC and S/390 targets, it is now possible to use a single
1451 gdbserver executable to debug both 32-bit and 64-bit programs.
1452 (This requires gdbserver itself to be built as a 64-bit executable.)
1454 - gdbserver uses the new noack protocol mode for TCP connections to
1455 reduce communications latency, if also supported and enabled in GDB.
1457 - Support for the sparc64-linux-gnu target is now included in
1460 - The amd64-linux build of gdbserver now supports debugging both
1461 32-bit and 64-bit programs.
1463 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1464 now support hardware watchpoints, and will use them automatically
1469 GDB now has support for scripting using Python. Whether this is
1470 available is determined at configure time.
1472 New GDB commands can now be written in Python.
1474 * Ada tasking support
1476 Ada tasks can now be inspected in GDB. The following commands have
1480 Print the list of Ada tasks.
1482 Print detailed information about task number N.
1484 Print the task number of the current task.
1486 Switch the context of debugging to task number N.
1488 * Support for user-defined prefixed commands. The "define" command can
1489 add new commands to existing prefixes, e.g. "target".
1491 * Multi-inferior, multi-process debugging.
1493 GDB now has generalized support for multi-inferior debugging. See
1494 "Debugging Multiple Inferiors" in the manual for more information.
1495 Although availability still depends on target support, the command
1496 set is more uniform now. The GNU/Linux specific multi-forks support
1497 has been migrated to this new framework. This implied some user
1498 visible changes; see "New commands" and also "Removed commands"
1501 * Target descriptions can now describe the target OS ABI. See the
1502 "Target Description Format" section in the user manual for more
1505 * Target descriptions can now describe "compatible" architectures
1506 to indicate that the target can execute applications for a different
1507 architecture in addition to those for the main target architecture.
1508 See the "Target Description Format" section in the user manual for
1511 * Multi-architecture debugging.
1513 GDB now includes general supports for debugging applications on
1514 hybrid systems that use more than one single processor architecture
1515 at the same time. Each such hybrid architecture still requires
1516 specific support to be added. The only hybrid architecture supported
1517 in this version of GDB is the Cell Broadband Engine.
1519 * GDB now supports integrated debugging of Cell/B.E. applications that
1520 use both the PPU and SPU architectures. To enable support for hybrid
1521 Cell/B.E. debugging, you need to configure GDB to support both the
1522 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1523 --enable-targets configure option.
1525 * Non-stop mode debugging.
1527 For some targets, GDB now supports an optional mode of operation in
1528 which you can examine stopped threads while other threads continue
1529 to execute freely. This is referred to as non-stop mode, with the
1530 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1531 section in the user manual for more information.
1533 To be able to support remote non-stop debugging, a remote stub needs
1534 to implement the non-stop mode remote protocol extensions, as
1535 described in the "Remote Non-Stop" section of the user manual. The
1536 GDB remote stub, gdbserver, has been adjusted to support these
1537 extensions on linux targets.
1539 * New commands (for set/show, see "New options" below)
1541 catch syscall [NAME(S) | NUMBER(S)]
1542 Catch system calls. Arguments, which should be names of system
1543 calls or their numbers, mean catch only those syscalls. Without
1544 arguments, every syscall will be caught. When the inferior issues
1545 any of the specified syscalls, GDB will stop and announce the system
1546 call, both when it is called and when its call returns. This
1547 feature is currently available with a native GDB running on the
1548 Linux Kernel, under the following architectures: x86, x86_64,
1549 PowerPC and PowerPC64.
1551 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1553 Search memory for a sequence of bytes.
1555 maint set python print-stack
1556 maint show python print-stack
1557 Show a stack trace when an error is encountered in a Python script.
1560 Invoke CODE by passing it to the Python interpreter.
1565 These allow macros to be defined, undefined, and listed
1569 Show operating system information about processes.
1572 List the inferiors currently under GDB's control.
1575 Switch focus to inferior number NUM.
1578 Detach from inferior number NUM.
1581 Kill inferior number NUM.
1585 set spu stop-on-load
1586 show spu stop-on-load
1587 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1589 set spu auto-flush-cache
1590 show spu auto-flush-cache
1591 Control whether to automatically flush the software-managed cache
1592 during Cell/B.E. debugging.
1594 set sh calling-convention
1595 show sh calling-convention
1596 Control the calling convention used when calling SH target functions.
1599 show debug timestamp
1600 Control display of timestamps with GDB debugging output.
1602 set disassemble-next-line
1603 show disassemble-next-line
1604 Control display of disassembled source lines or instructions when
1607 set remote noack-packet
1608 show remote noack-packet
1609 Set/show the use of remote protocol QStartNoAckMode packet. See above
1610 under "New remote packets."
1612 set remote query-attached-packet
1613 show remote query-attached-packet
1614 Control use of remote protocol `qAttached' (query-attached) packet.
1616 set remote read-siginfo-object
1617 show remote read-siginfo-object
1618 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1621 set remote write-siginfo-object
1622 show remote write-siginfo-object
1623 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1626 set remote reverse-continue
1627 show remote reverse-continue
1628 Control use of remote protocol 'bc' (reverse-continue) packet.
1630 set remote reverse-step
1631 show remote reverse-step
1632 Control use of remote protocol 'bs' (reverse-step) packet.
1634 set displaced-stepping
1635 show displaced-stepping
1636 Control displaced stepping mode. Displaced stepping is a way to
1637 single-step over breakpoints without removing them from the debuggee.
1638 Also known as "out-of-line single-stepping".
1641 show debug displaced
1642 Control display of debugging info for displaced stepping.
1644 maint set internal-error
1645 maint show internal-error
1646 Control what GDB does when an internal error is detected.
1648 maint set internal-warning
1649 maint show internal-warning
1650 Control what GDB does when an internal warning is detected.
1655 Use a wrapper program to launch programs for debugging.
1657 set multiple-symbols (all|ask|cancel)
1658 show multiple-symbols
1659 The value of this variable can be changed to adjust the debugger behavior
1660 when an expression or a breakpoint location contains an ambiguous symbol
1661 name (an overloaded function name, for instance).
1663 set breakpoint always-inserted
1664 show breakpoint always-inserted
1665 Keep breakpoints always inserted in the target, as opposed to inserting
1666 them when resuming the target, and removing them when the target stops.
1667 This option can improve debugger performance on slow remote targets.
1669 set arm fallback-mode (arm|thumb|auto)
1670 show arm fallback-mode
1671 set arm force-mode (arm|thumb|auto)
1673 These commands control how ARM GDB determines whether instructions
1674 are ARM or Thumb. The default for both settings is auto, which uses
1675 the current CPSR value for instructions without symbols; previous
1676 versions of GDB behaved as if "set arm fallback-mode arm".
1678 set disable-randomization
1679 show disable-randomization
1680 Standalone programs run with the virtual address space randomization enabled
1681 by default on some platforms. This option keeps the addresses stable across
1682 multiple debugging sessions.
1686 Control whether other threads are stopped or not when some thread hits
1691 Requests that asynchronous execution is enabled in the target, if available.
1692 In this case, it's possible to resume target in the background, and interact
1693 with GDB while the target is running. "show target-async" displays the
1694 current state of asynchronous execution of the target.
1696 set target-wide-charset
1697 show target-wide-charset
1698 The target-wide-charset is the name of the character set that GDB
1699 uses when printing characters whose type is wchar_t.
1701 set tcp auto-retry (on|off)
1703 set tcp connect-timeout
1704 show tcp connect-timeout
1705 These commands allow GDB to retry failed TCP connections to a remote stub
1706 with a specified timeout period; this is useful if the stub is launched
1707 in parallel with GDB but may not be ready to accept connections immediately.
1709 set libthread-db-search-path
1710 show libthread-db-search-path
1711 Control list of directories which GDB will search for appropriate
1714 set schedule-multiple (on|off)
1715 show schedule-multiple
1716 Allow GDB to resume all threads of all processes or only threads of
1717 the current process.
1721 Use more aggressive caching for accesses to the stack. This improves
1722 performance of remote debugging (particularly backtraces) without
1723 affecting correctness.
1725 set interactive-mode (on|off|auto)
1726 show interactive-mode
1727 Control whether GDB runs in interactive mode (on) or not (off).
1728 When in interactive mode, GDB waits for the user to answer all
1729 queries. Otherwise, GDB does not wait and assumes the default
1730 answer. When set to auto (the default), GDB determines which
1731 mode to use based on the stdin settings.
1736 For program forks, this is replaced by the new more generic `info
1737 inferiors' command. To list checkpoints, you can still use the
1738 `info checkpoints' command, which was an alias for the `info forks'
1742 Replaced by the new `inferior' command. To switch between
1743 checkpoints, you can still use the `restart' command, which was an
1744 alias for the `fork' command.
1747 This is removed, since some targets don't have a notion of
1748 processes. To switch between processes, you can still use the
1749 `inferior' command using GDB's own inferior number.
1752 For program forks, this is replaced by the new more generic `kill
1753 inferior' command. To delete a checkpoint, you can still use the
1754 `delete checkpoint' command, which was an alias for the `delete
1758 For program forks, this is replaced by the new more generic `detach
1759 inferior' command. To detach a checkpoint, you can still use the
1760 `detach checkpoint' command, which was an alias for the `detach
1763 * New native configurations
1765 x86/x86_64 Darwin i[34567]86-*-darwin*
1767 x86_64 MinGW x86_64-*-mingw*
1771 Lattice Mico32 lm32-*
1772 x86 DICOS i[34567]86-*-dicos*
1773 x86_64 DICOS x86_64-*-dicos*
1776 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1777 (mingw32ce) debugging.
1783 These commands were actually not implemented on any target.
1785 *** Changes in GDB 6.8
1787 * New native configurations
1789 NetBSD/hppa hppa*-*netbsd*
1790 Xtensa GNU/Linux xtensa*-*-linux*
1794 NetBSD/hppa hppa*-*-netbsd*
1795 Xtensa GNU/Lunux xtensa*-*-linux*
1797 * Change in command line behavior -- corefiles vs. process ids.
1799 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1800 attaching to process NUMBER fails, GDB no longer attempts to open a
1801 core file named NUMBER. Attaching to a program using the -c option
1802 is no longer supported. Instead, use the '-p' or '--pid' options.
1804 * GDB can now be built as a native debugger for debugging Windows x86
1805 (mingw32) Portable Executable (PE) programs.
1807 * Pending breakpoints no longer change their number when their address
1810 * GDB now supports breakpoints with multiple locations,
1811 including breakpoints on C++ constructors, inside C++ templates,
1812 and in inlined functions.
1814 * GDB's ability to debug optimized code has been improved. GDB more
1815 accurately identifies function bodies and lexical blocks that occupy
1816 more than one contiguous range of addresses.
1818 * Target descriptions can now describe registers for PowerPC.
1820 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1821 registers on PowerPC targets.
1823 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1824 targets even when the libthread_db library is not available.
1826 * The GDB remote stub, gdbserver, now supports the new file transfer
1827 commands (remote put, remote get, and remote delete).
1829 * The GDB remote stub, gdbserver, now supports run and attach in
1830 extended-remote mode.
1832 * hppa*64*-*-hpux11* target broken
1833 The debugger is unable to start a program and fails with the following
1834 error: "Error trying to get information about dynamic linker".
1835 The gdb-6.7 release is also affected.
1837 * GDB now supports the --enable-targets= configure option to allow
1838 building a single GDB executable that supports multiple remote
1839 target architectures.
1841 * GDB now supports debugging C and C++ programs which use the
1842 Decimal Floating Point extension. In addition, the PowerPC target
1843 now has a set of pseudo-registers to inspect decimal float values
1844 stored in two consecutive float registers.
1846 * The -break-insert MI command can optionally create pending
1849 * Improved support for debugging Ada
1850 Many improvements to the Ada language support have been made. These
1852 - Better support for Ada2005 interface types
1853 - Improved handling of arrays and slices in general
1854 - Better support for Taft-amendment types
1855 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1857 - Improved command completion in Ada
1860 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1865 set print frame-arguments (all|scalars|none)
1866 show print frame-arguments
1867 The value of this variable can be changed to control which argument
1868 values should be printed by the debugger when displaying a frame.
1873 Transfer files to and from a remote target, and delete remote files.
1880 Transfer files to and from a remote target, and delete remote files.
1882 * New remote packets
1889 Open, close, read, write, and delete files on the remote system.
1892 Attach to an existing process on the remote system, in extended-remote
1896 Run a new process on the remote system, in extended-remote mode.
1898 *** Changes in GDB 6.7
1900 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1901 bfd, libiberty and opcodes, as revealed by static analysis donated by
1902 Coverity, Inc. (http://scan.coverity.com).
1904 * When looking up multiply-defined global symbols, GDB will now prefer the
1905 symbol definition in the current shared library if it was built using the
1906 -Bsymbolic linker option.
1908 * When the Text User Interface (TUI) is not configured, GDB will now
1909 recognize the -tui command-line option and print a message that the TUI
1912 * The GDB remote stub, gdbserver, now has lower overhead for high
1913 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1915 * GDB for MIPS targets now autodetects whether a remote target provides
1916 32-bit or 64-bit register values.
1918 * Support for C++ member pointers has been improved.
1920 * GDB now understands XML target descriptions, which specify the
1921 target's overall architecture. GDB can read a description from
1922 a local file or over the remote serial protocol.
1924 * Vectors of single-byte data use a new integer type which is not
1925 automatically displayed as character or string data.
1927 * The /s format now works with the print command. It displays
1928 arrays of single-byte integers and pointers to single-byte integers
1931 * Target descriptions can now describe target-specific registers,
1932 for architectures which have implemented the support (currently
1933 only ARM, M68K, and MIPS).
1935 * GDB and the GDB remote stub, gdbserver, now support the XScale
1938 * The GDB remote stub, gdbserver, has been updated to support
1939 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1940 has been rewritten to use the standard GDB remote protocol.
1942 * GDB can now step into C++ functions which are called through thunks.
1944 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1946 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1947 layout. It also supports a TextSeg= and DataSeg= response when only
1948 segment base addresses (rather than offsets) are available.
1950 * The /i format now outputs any trailing branch delay slot instructions
1951 immediately following the last instruction within the count specified.
1953 * The GDB remote protocol "T" stop reply packet now supports a
1954 "library" response. Combined with the new "qXfer:libraries:read"
1955 packet, this response allows GDB to debug shared libraries on targets
1956 where the operating system manages the list of loaded libraries (e.g.
1957 Windows and SymbianOS).
1959 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1960 (DLLs) on Windows and Windows CE targets.
1962 * GDB now supports a faster verification that a .debug file matches its binary
1963 according to its build-id signature, if the signature is present.
1969 Enable or disable hardware flow control (RTS/CTS) on the serial port
1970 when debugging using remote targets.
1972 set mem inaccessible-by-default
1973 show mem inaccessible-by-default
1974 If the target supplies a memory map, for instance via the remote
1975 protocol's "qXfer:memory-map:read" packet, setting this variable
1976 prevents GDB from accessing memory outside the memory map. This
1977 is useful for targets with memory mapped registers or which react
1978 badly to accesses of unmapped address space.
1980 set breakpoint auto-hw
1981 show breakpoint auto-hw
1982 If the target supplies a memory map, for instance via the remote
1983 protocol's "qXfer:memory-map:read" packet, setting this variable
1984 lets GDB use hardware breakpoints automatically for memory regions
1985 where it can not use software breakpoints. This covers both the
1986 "break" command and internal breakpoints used for other commands
1987 including "next" and "finish".
1990 catch exception unhandled
1991 Stop the program execution when Ada exceptions are raised.
1994 Stop the program execution when an Ada assertion failed.
1998 Set an alternate system root for target files. This is a more
1999 general version of "set solib-absolute-prefix", which is now
2000 an alias to "set sysroot".
2003 Provide extended SPU facility status information. This set of
2004 commands is available only when debugging the Cell/B.E. SPU
2007 * New native configurations
2009 OpenBSD/sh sh*-*openbsd*
2012 unset tdesc filename
2014 Use the specified local file as an XML target description, and do
2015 not query the target for its built-in description.
2019 OpenBSD/sh sh*-*-openbsd*
2020 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2021 Toshiba Media Processor mep-elf
2023 * New remote packets
2026 Ignore the specified signals; pass them directly to the debugged program
2027 without stopping other threads or reporting them to GDB.
2029 qXfer:features:read:
2030 Read an XML target description from the target, which describes its
2035 Read or write contents of an spufs file on the target system. These
2036 packets are available only on the Cell/B.E. SPU architecture.
2038 qXfer:libraries:read:
2039 Report the loaded shared libraries. Combined with new "T" packet
2040 response, this packet allows GDB to debug shared libraries on
2041 targets where the operating system manages the list of loaded
2042 libraries (e.g. Windows and SymbianOS).
2046 Support for these obsolete configurations has been removed.
2054 i[34567]86-*-lynxos*
2055 i[34567]86-*-netware*
2056 i[34567]86-*-sco3.2v5*
2057 i[34567]86-*-sco3.2v4*
2059 i[34567]86-*-sysv4.2*
2062 i[34567]86-*-unixware2*
2063 i[34567]86-*-unixware*
2072 * Other removed features
2079 Various m68k-only ROM monitors.
2086 Various Renesas ROM monitors and debugging interfaces for SH and
2091 Support for a Macraigor serial interface to on-chip debugging.
2092 GDB does not directly support the newer parallel or USB
2097 A debug information format. The predecessor to DWARF 2 and
2098 DWARF 3, which are still supported.
2100 Support for the HP aCC compiler on HP-UX/PA-RISC
2102 SOM-encapsulated symbolic debugging information, automatic
2103 invocation of pxdb, and the aCC custom C++ ABI. This does not
2104 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2105 with aCC can still be debugged on an assembly level.
2107 MIPS ".pdr" sections
2109 A MIPS-specific format used to describe stack frame layout
2110 in debugging information.
2114 GDB could work with an older version of Guile to debug
2115 the interpreter and Scheme programs running in it.
2117 set mips stack-arg-size
2118 set mips saved-gpreg-size
2120 Use "set mips abi" to control parameter passing for MIPS.
2122 *** Changes in GDB 6.6
2127 Cell Broadband Engine SPU spu-elf
2129 * GDB can now be configured as a cross-debugger targeting native Windows
2130 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2131 running on a Windows system over TCP/IP to debug Windows programs.
2133 * The GDB remote stub, gdbserver, has been updated to support Windows and
2134 Cygwin debugging. Both single-threaded and multi-threaded programs are
2137 * The "set trust-readonly-sections" command works again. This command was
2138 broken in GDB 6.3, 6.4, and 6.5.
2140 * The "load" command now supports writing to flash memory, if the remote
2141 stub provides the required support.
2143 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2144 longer requires symbolic debug information (e.g. DWARF-2).
2149 unset substitute-path
2150 show substitute-path
2151 Manage a list of substitution rules that GDB uses to rewrite the name
2152 of the directories where the sources are located. This can be useful
2153 for instance when the sources were moved to a different location
2154 between compilation and debugging.
2158 Print each CLI command as it is executed. Each command is prefixed with
2159 a number of `+' symbols representing the nesting depth.
2160 The source command now has a `-v' option to enable the same feature.
2164 The ARM Demon monitor support (RDP protocol, "target rdp").
2166 Kernel Object Display, an embedded debugging feature which only worked with
2167 an obsolete version of Cisco IOS.
2169 The 'set download-write-size' and 'show download-write-size' commands.
2171 * New remote packets
2174 Tell a stub about GDB client features, and request remote target features.
2175 The first feature implemented is PacketSize, which allows the target to
2176 specify the size of packets it can handle - to minimize the number of
2177 packets required and improve performance when connected to a remote
2181 Fetch an OS auxilliary vector from the remote stub. This packet is a
2182 more efficient replacement for qPart:auxv:read.
2184 qXfer:memory-map:read:
2185 Fetch a memory map from the remote stub, including information about
2186 RAM, ROM, and flash memory devices.
2191 Erase and program a flash memory device.
2193 * Removed remote packets
2196 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2197 used it, and only gdbserver implemented it.
2199 *** Changes in GDB 6.5
2203 Renesas M32C/M16C m32c-elf
2205 Morpho Technologies ms1 ms1-elf
2209 init-if-undefined Initialize a convenience variable, but
2210 only if it doesn't already have a value.
2212 The following commands are presently only implemented for native GNU/Linux:
2214 checkpoint Save a snapshot of the program state.
2216 restart <n> Return the program state to a
2217 previously saved state.
2219 info checkpoints List currently saved checkpoints.
2221 delete-checkpoint <n> Delete a previously saved checkpoint.
2223 set|show detach-on-fork Tell gdb whether to detach from a newly
2224 forked process, or to keep debugging it.
2226 info forks List forks of the user program that
2227 are available to be debugged.
2229 fork <n> Switch to debugging one of several
2230 forks of the user program that are
2231 available to be debugged.
2233 delete-fork <n> Delete a fork from the list of forks
2234 that are available to be debugged (and
2235 kill the forked process).
2237 detach-fork <n> Delete a fork from the list of forks
2238 that are available to be debugged (and
2239 allow the process to continue).
2243 Morpho Technologies ms2 ms1-elf
2245 * Improved Windows host support
2247 GDB now builds as a cross debugger hosted on i686-mingw32, including
2248 native console support, and remote communications using either
2249 network sockets or serial ports.
2251 * Improved Modula-2 language support
2253 GDB can now print most types in the Modula-2 syntax. This includes:
2254 basic types, set types, record types, enumerated types, range types,
2255 pointer types and ARRAY types. Procedure var parameters are correctly
2256 printed and hexadecimal addresses and character constants are also
2257 written in the Modula-2 syntax. Best results can be obtained by using
2258 GNU Modula-2 together with the -gdwarf-2 command line option.
2262 The ARM rdi-share module.
2264 The Netware NLM debug server.
2266 *** Changes in GDB 6.4
2268 * New native configurations
2270 OpenBSD/arm arm*-*-openbsd*
2271 OpenBSD/mips64 mips64-*-openbsd*
2275 Morpho Technologies ms1 ms1-elf
2277 * New command line options
2279 --batch-silent As for --batch, but totally silent.
2280 --return-child-result The debugger will exist with the same value
2281 the child (debugged) program exited with.
2282 --eval-command COMMAND, -ex COMMAND
2283 Execute a single GDB CLI command. This may be
2284 specified multiple times and in conjunction
2285 with the --command (-x) option.
2287 * Deprecated commands removed
2289 The following commands, that were deprecated in 2000, have been
2293 set|show arm disassembly-flavor set|show arm disassembler
2294 othernames set arm disassembler
2295 set|show remotedebug set|show debug remote
2296 set|show archdebug set|show debug arch
2297 set|show eventdebug set|show debug event
2300 * New BSD user-level threads support
2302 It is now possible to debug programs using the user-level threads
2303 library on OpenBSD and FreeBSD. Currently supported (target)
2306 FreeBSD/amd64 x86_64-*-freebsd*
2307 FreeBSD/i386 i386-*-freebsd*
2308 OpenBSD/i386 i386-*-openbsd*
2310 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2311 are not yet supported.
2313 * New support for Matsushita MN10300 w/sim added
2314 (Work in progress). mn10300-elf.
2316 * REMOVED configurations and files
2318 VxWorks and the XDR protocol *-*-vxworks
2319 Motorola MCORE mcore-*-*
2320 National Semiconductor NS32000 ns32k-*-*
2322 * New "set print array-indexes" command
2324 After turning this setting "on", GDB prints the index of each element
2325 when displaying arrays. The default is "off" to preserve the previous
2328 * VAX floating point support
2330 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2332 * User-defined command support
2334 In addition to using $arg0..$arg9 for argument passing, it is now possible
2335 to use $argc to determine now many arguments have been passed. See the
2336 section on user-defined commands in the user manual for more information.
2338 *** Changes in GDB 6.3:
2340 * New command line option
2342 GDB now accepts -l followed by a number to set the timeout for remote
2345 * GDB works with GCC -feliminate-dwarf2-dups
2347 GDB now supports a more compact representation of DWARF-2 debug
2348 information using DW_FORM_ref_addr references. These are produced
2349 by GCC with the option -feliminate-dwarf2-dups and also by some
2350 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2351 to use -feliminate-dwarf2-dups.
2353 * Internationalization
2355 When supported by the host system, GDB will be built with
2356 internationalization (libintl). The task of marking up the sources is
2357 continued, we're looking forward to our first translation.
2361 Initial support for debugging programs compiled with the GNAT
2362 implementation of the Ada programming language has been integrated
2363 into GDB. In this release, support is limited to expression evaluation.
2365 * New native configurations
2367 GNU/Linux/m32r m32r-*-linux-gnu
2371 GDB's remote protocol now includes support for the 'p' packet. This
2372 packet is used to fetch individual registers from a remote inferior.
2374 * END-OF-LIFE registers[] compatibility module
2376 GDB's internal register infrastructure has been completely rewritten.
2377 The new infrastructure making possible the implementation of key new
2378 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2381 GDB 6.3 will be the last release to include the the registers[]
2382 compatibility module that allowed out-of-date configurations to
2383 continue to work. This change directly impacts the following
2393 powerpc bdm protocol
2395 Unless there is activity to revive these configurations, they will be
2396 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2398 * OBSOLETE configurations and files
2400 Configurations that have been declared obsolete in this release have
2401 been commented out. Unless there is activity to revive these
2402 configurations, the next release of GDB will have their sources
2403 permanently REMOVED.
2412 *** Changes in GDB 6.2.1:
2414 * MIPS `break main; run' gave an heuristic-fence-post warning
2416 When attempting to run even a simple program, a warning about
2417 heuristic-fence-post being hit would be reported. This problem has
2420 * MIPS IRIX 'long double' crashed GDB
2422 When examining a long double variable, GDB would get a segmentation
2423 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2424 IRIX long double values).
2428 A bug in the VAX stack code was causing problems with the "next"
2429 command. This problem has been fixed.
2431 *** Changes in GDB 6.2:
2433 * Fix for ``many threads''
2435 On GNU/Linux systems that use the NPTL threads library, a program
2436 rapidly creating and deleting threads would confuse GDB leading to the
2439 ptrace: No such process.
2440 thread_db_get_info: cannot get thread info: generic error
2442 This problem has been fixed.
2444 * "-async" and "-noasync" options removed.
2446 Support for the broken "-noasync" option has been removed (it caused
2449 * New ``start'' command.
2451 This command runs the program until the begining of the main procedure.
2453 * New BSD Kernel Data Access Library (libkvm) interface
2455 Using ``target kvm'' it is now possible to debug kernel core dumps and
2456 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2457 platforms. Currently supported (native-only) configurations are:
2459 FreeBSD/amd64 x86_64-*-freebsd*
2460 FreeBSD/i386 i?86-*-freebsd*
2461 NetBSD/i386 i?86-*-netbsd*
2462 NetBSD/m68k m68*-*-netbsd*
2463 NetBSD/sparc sparc-*-netbsd*
2464 OpenBSD/amd64 x86_64-*-openbsd*
2465 OpenBSD/i386 i?86-*-openbsd*
2466 OpenBSD/m68k m68*-openbsd*
2467 OpenBSD/sparc sparc-*-openbsd*
2469 * Signal trampoline code overhauled
2471 Many generic problems with GDB's signal handling code have been fixed.
2472 These include: backtraces through non-contiguous stacks; recognition
2473 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2474 call; backtrace through a signal trampoline; step into and out of
2475 signal handlers; and single-stepping in the signal trampoline.
2477 Please note that kernel bugs are a limiting factor here. These
2478 features have been shown to work on an s390 GNU/Linux system that
2479 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2481 * Cygwin support for DWARF 2 added.
2483 * New native configurations
2485 GNU/Linux/hppa hppa*-*-linux*
2486 OpenBSD/hppa hppa*-*-openbsd*
2487 OpenBSD/m68k m68*-*-openbsd*
2488 OpenBSD/m88k m88*-*-openbsd*
2489 OpenBSD/powerpc powerpc-*-openbsd*
2490 NetBSD/vax vax-*-netbsd*
2491 OpenBSD/vax vax-*-openbsd*
2493 * END-OF-LIFE frame compatibility module
2495 GDB's internal frame infrastructure has been completely rewritten.
2496 The new infrastructure making it possible to support key new features
2497 including DWARF 2 Call Frame Information. To aid in the task of
2498 migrating old configurations to this new infrastructure, a
2499 compatibility module, that allowed old configurations to continue to
2500 work, was also included.
2502 GDB 6.2 will be the last release to include this frame compatibility
2503 module. This change directly impacts the following configurations:
2513 Unless there is activity to revive these configurations, they will be
2514 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2516 * REMOVED configurations and files
2518 Sun 3, running SunOS 3 m68*-*-sunos3*
2519 Sun 3, running SunOS 4 m68*-*-sunos4*
2520 Sun 2, running SunOS 3 m68000-*-sunos3*
2521 Sun 2, running SunOS 4 m68000-*-sunos4*
2522 Motorola 680x0 running LynxOS m68*-*-lynxos*
2523 AT&T 3b1/Unix pc m68*-att-*
2524 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2525 decstation mips-dec-* mips-little-*
2526 riscos mips-*-riscos* mips-*-sysv*
2527 sonymips mips-sony-*
2528 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2530 *** Changes in GDB 6.1.1:
2532 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2534 The TUI (Text-mode User Interface) is now built as part of a default
2535 GDB configuration. It is enabled by either selecting the TUI with the
2536 command line option "-i=tui" or by running the separate "gdbtui"
2537 program. For more information on the TUI, see the manual "Debugging
2540 * Pending breakpoint support (also included in GDB 6.1)
2542 Support has been added to allow you to specify breakpoints in shared
2543 libraries that have not yet been loaded. If a breakpoint location
2544 cannot be found, and the "breakpoint pending" option is set to auto,
2545 GDB queries you if you wish to make the breakpoint pending on a future
2546 shared-library load. If and when GDB resolves the breakpoint symbol,
2547 the pending breakpoint is removed as one or more regular breakpoints
2550 Pending breakpoints are very useful for GCJ Java debugging.
2552 * Fixed ISO-C build problems
2554 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2555 non ISO-C code that stopped them being built using a more strict ISO-C
2556 compiler (e.g., IBM's C compiler).
2558 * Fixed build problem on IRIX 5
2560 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2561 wasn't able to compile compile on an IRIX 5 system.
2563 * Added execute permission to gdb/gdbserver/configure
2565 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2566 permission. This bug would cause configure to fail on a number of
2567 systems (Solaris, IRIX). Ref: server/519.
2569 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2571 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2572 has been updated to use constant array sizes.
2574 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2576 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2577 its generated DWARF Call Frame Info. This encoding was causing GDB to
2578 panic, that panic has been fixed. Ref: gdb/1628.
2580 * Fixed a problem when examining parameters in shared library code.
2582 When examining parameters in optimized shared library code generated
2583 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2584 not available''. GDB now correctly displays the variable's value.
2586 *** Changes in GDB 6.1:
2588 * Removed --with-mmalloc
2590 Support for the mmalloc memory manager has been removed, as it
2591 conflicted with the internal gdb byte cache.
2593 * Changes in AMD64 configurations
2595 The AMD64 target now includes the %cs and %ss registers. As a result
2596 the AMD64 remote protocol has changed; this affects the floating-point
2597 and SSE registers. If you rely on those registers for your debugging,
2598 you should upgrade gdbserver on the remote side.
2600 * Revised SPARC target
2602 The SPARC target has been completely revised, incorporating the
2603 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2604 support for LynxOS and SunOS 4 has been dropped. Calling functions
2605 from within GDB on operating systems with a non-executable stack
2606 (Solaris, OpenBSD) now works.
2610 GDB has a new C++ demangler which does a better job on the mangled
2611 names generated by current versions of g++. It also runs faster, so
2612 with this and other changes gdb should now start faster on large C++
2615 * DWARF 2 Location Expressions
2617 GDB support for location expressions has been extended to support function
2618 arguments and frame bases. Older versions of GDB could crash when they
2621 * C++ nested types and namespaces
2623 GDB's support for nested types and namespaces in C++ has been
2624 improved, especially if you use the DWARF 2 debugging format. (This
2625 is the default for recent versions of GCC on most platforms.)
2626 Specifically, if you have a class "Inner" defined within a class or
2627 namespace "Outer", then GDB realizes that the class's name is
2628 "Outer::Inner", not simply "Inner". This should greatly reduce the
2629 frequency of complaints about not finding RTTI symbols. In addition,
2630 if you are stopped at inside of a function defined within a namespace,
2631 GDB modifies its name lookup accordingly.
2633 * New native configurations
2635 NetBSD/amd64 x86_64-*-netbsd*
2636 OpenBSD/amd64 x86_64-*-openbsd*
2637 OpenBSD/alpha alpha*-*-openbsd*
2638 OpenBSD/sparc sparc-*-openbsd*
2639 OpenBSD/sparc64 sparc64-*-openbsd*
2641 * New debugging protocols
2643 M32R with SDI protocol m32r-*-elf*
2645 * "set prompt-escape-char" command deleted.
2647 The command "set prompt-escape-char" has been deleted. This command,
2648 and its very obscure effet on GDB's prompt, was never documented,
2649 tested, nor mentioned in the NEWS file.
2651 * OBSOLETE configurations and files
2653 Configurations that have been declared obsolete in this release have
2654 been commented out. Unless there is activity to revive these
2655 configurations, the next release of GDB will have their sources
2656 permanently REMOVED.
2658 Sun 3, running SunOS 3 m68*-*-sunos3*
2659 Sun 3, running SunOS 4 m68*-*-sunos4*
2660 Sun 2, running SunOS 3 m68000-*-sunos3*
2661 Sun 2, running SunOS 4 m68000-*-sunos4*
2662 Motorola 680x0 running LynxOS m68*-*-lynxos*
2663 AT&T 3b1/Unix pc m68*-att-*
2664 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2665 decstation mips-dec-* mips-little-*
2666 riscos mips-*-riscos* mips-*-sysv*
2667 sonymips mips-sony-*
2668 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2670 * REMOVED configurations and files
2672 SGI Irix-4.x mips-sgi-irix4 or iris4
2673 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2674 Z8000 simulator z8k-zilog-none or z8ksim
2675 Matsushita MN10200 w/simulator mn10200-*-*
2676 H8/500 simulator h8500-hitachi-hms or h8500hms
2677 HP/PA running BSD hppa*-*-bsd*
2678 HP/PA running OSF/1 hppa*-*-osf*
2679 HP/PA Pro target hppa*-*-pro*
2680 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2681 386BSD i[3456]86-*-bsd*
2682 Sequent family i[3456]86-sequent-sysv4*
2683 i[3456]86-sequent-sysv*
2684 i[3456]86-sequent-bsd*
2685 SPARC running LynxOS sparc-*-lynxos*
2686 SPARC running SunOS 4 sparc-*-sunos4*
2687 Tsqware Sparclet sparclet-*-*
2688 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2690 *** Changes in GDB 6.0:
2694 Support for debugging the Objective-C programming language has been
2695 integrated into GDB.
2697 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2699 DWARF 2's Call Frame Information makes available compiler generated
2700 information that more exactly describes the program's run-time stack.
2701 By using this information, GDB is able to provide more robust stack
2704 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2705 have been updated to use a new backtrace mechanism which includes
2706 DWARF 2 CFI support.
2710 GDB's remote protocol has been extended to include support for hosted
2711 file I/O (where the remote target uses GDB's file system). See GDB's
2712 remote protocol documentation for details.
2714 * All targets using the new architecture framework.
2716 All of GDB's targets have been updated to use the new internal
2717 architecture framework. The way is now open for future GDB releases
2718 to include cross-architecture native debugging support (i386 on amd64,
2721 * GNU/Linux's Thread Local Storage (TLS)
2723 GDB now includes support for for the GNU/Linux implementation of
2724 per-thread variables.
2726 * GNU/Linux's Native POSIX Thread Library (NPTL)
2728 GDB's thread code has been updated to work with either the new
2729 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2731 * Separate debug info.
2733 GDB, in conjunction with BINUTILS, now supports a mechanism for
2734 automatically loading debug information from a separate file. Instead
2735 of shipping full debug and non-debug versions of system libraries,
2736 system integrators can now instead ship just the stripped libraries
2737 and optional debug files.
2739 * DWARF 2 Location Expressions
2741 DWARF 2 Location Expressions allow the compiler to more completely
2742 describe the location of variables (even in optimized code) to the
2745 GDB now includes preliminary support for location expressions (support
2746 for DW_OP_piece is still missing).
2750 A number of long standing bugs that caused GDB to die while starting a
2751 Java application have been fixed. GDB's Java support is now
2752 considered "useable".
2754 * GNU/Linux support for fork, vfork, and exec.
2756 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2757 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2760 * GDB supports logging output to a file
2762 There are two new commands, "set logging" and "show logging", which can be
2763 used to capture GDB's output to a file.
2765 * The meaning of "detach" has changed for gdbserver
2767 The "detach" command will now resume the application, as documented. To
2768 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2771 * d10v, m68hc11 `regs' command deprecated
2773 The `info registers' command has been updated so that it displays the
2774 registers using a format identical to the old `regs' command.
2778 A new command, "maint set profile on/off", has been added. This command can
2779 be used to enable or disable profiling while running GDB, to profile a
2780 session or a set of commands. In addition there is a new configure switch,
2781 "--enable-profiling", which will cause GDB to be compiled with profiling
2782 data, for more informative profiling results.
2784 * Default MI syntax changed to "mi2".
2786 The default MI (machine interface) syntax, enabled by the command line
2787 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2788 "mi1", can be enabled by specifying the option "-i=mi1".
2790 Support for the original "mi0" syntax (included in GDB 5.0) has been
2793 Fix for gdb/192: removed extraneous space when displaying frame level.
2794 Fix for gdb/672: update changelist is now output in mi list format.
2795 Fix for gdb/702: a -var-assign that updates the value now shows up
2796 in a subsequent -var-update.
2798 * New native configurations.
2800 FreeBSD/amd64 x86_64-*-freebsd*
2802 * Multi-arched targets.
2804 HP/PA HPUX11 hppa*-*-hpux*
2805 Renesas M32R/D w/simulator m32r-*-elf*
2807 * OBSOLETE configurations and files
2809 Configurations that have been declared obsolete in this release have
2810 been commented out. Unless there is activity to revive these
2811 configurations, the next release of GDB will have their sources
2812 permanently REMOVED.
2814 Z8000 simulator z8k-zilog-none or z8ksim
2815 Matsushita MN10200 w/simulator mn10200-*-*
2816 H8/500 simulator h8500-hitachi-hms or h8500hms
2817 HP/PA running BSD hppa*-*-bsd*
2818 HP/PA running OSF/1 hppa*-*-osf*
2819 HP/PA Pro target hppa*-*-pro*
2820 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2821 Sequent family i[3456]86-sequent-sysv4*
2822 i[3456]86-sequent-sysv*
2823 i[3456]86-sequent-bsd*
2824 Tsqware Sparclet sparclet-*-*
2825 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2827 * REMOVED configurations and files
2830 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2831 IBM AIX PS/2 i[3456]86-*-aix
2832 i386 running Mach 3.0 i[3456]86-*-mach3*
2833 i386 running Mach i[3456]86-*-mach*
2834 i386 running OSF/1 i[3456]86-*osf1mk*
2835 HP/Apollo 68k Family m68*-apollo*-sysv*,
2837 m68*-hp-bsd*, m68*-hp-hpux*
2838 Argonaut Risc Chip (ARC) arc-*-*
2839 Mitsubishi D30V d30v-*-*
2840 Fujitsu FR30 fr30-*-elf*
2841 OS/9000 i[34]86-*-os9k
2842 I960 with MON960 i960-*-coff
2844 * MIPS $fp behavior changed
2846 The convenience variable $fp, for the MIPS, now consistently returns
2847 the address of the current frame's base. Previously, depending on the
2848 context, $fp could refer to either $sp or the current frame's base
2849 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2850 The GNU Source-Level Debugger''.
2852 *** Changes in GDB 5.3:
2854 * GNU/Linux shared library multi-threaded performance improved.
2856 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2857 `/proc', in preference to `ptrace' for memory reads. This may result
2858 in an improvement in the start-up time of multi-threaded, shared
2859 library applications when run under GDB. One GDB user writes: ``loads
2860 shared libs like mad''.
2862 * ``gdbserver'' now supports multi-threaded applications on some targets
2864 Support for debugging multi-threaded applications which use
2865 the GNU/Linux LinuxThreads package has been added for
2866 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2867 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2869 * GDB now supports C/C++ preprocessor macros.
2871 GDB now expands preprocessor macro invocations in C/C++ expressions,
2872 and provides various commands for showing macro definitions and how
2875 The new command `macro expand EXPRESSION' expands any macro
2876 invocations in expression, and shows the result.
2878 The new command `show macro MACRO-NAME' shows the definition of the
2879 macro named MACRO-NAME, and where it was defined.
2881 Most compilers don't include information about macros in the debugging
2882 information by default. In GCC 3.1, for example, you need to compile
2883 your program with the options `-gdwarf-2 -g3'. If the macro
2884 information is present in the executable, GDB will read it.
2886 * Multi-arched targets.
2888 DEC Alpha (partial) alpha*-*-*
2889 DEC VAX (partial) vax-*-*
2891 National Semiconductor NS32000 (partial) ns32k-*-*
2892 Motorola 68000 (partial) m68k-*-*
2893 Motorola MCORE mcore-*-*
2897 Fujitsu FRV architecture added by Red Hat frv*-*-*
2900 * New native configurations
2902 Alpha NetBSD alpha*-*-netbsd*
2903 SH NetBSD sh*-*-netbsdelf*
2904 MIPS NetBSD mips*-*-netbsd*
2905 UltraSPARC NetBSD sparc64-*-netbsd*
2907 * OBSOLETE configurations and files
2909 Configurations that have been declared obsolete in this release have
2910 been commented out. Unless there is activity to revive these
2911 configurations, the next release of GDB will have their sources
2912 permanently REMOVED.
2914 Mitsubishi D30V d30v-*-*
2915 OS/9000 i[34]86-*-os9k
2916 IBM AIX PS/2 i[3456]86-*-aix
2917 Fujitsu FR30 fr30-*-elf*
2918 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2919 Argonaut Risc Chip (ARC) arc-*-*
2920 i386 running Mach 3.0 i[3456]86-*-mach3*
2921 i386 running Mach i[3456]86-*-mach*
2922 i386 running OSF/1 i[3456]86-*osf1mk*
2923 HP/Apollo 68k Family m68*-apollo*-sysv*,
2925 m68*-hp-bsd*, m68*-hp-hpux*
2926 I960 with MON960 i960-*-coff
2928 * OBSOLETE languages
2930 CHILL, a Pascal like language used by telecommunications companies.
2932 * REMOVED configurations and files
2934 AMD 29k family via UDI a29k-amd-udi, udi29k
2935 A29K VxWorks a29k-*-vxworks
2936 AMD 29000 embedded, using EBMON a29k-none-none
2937 AMD 29000 embedded with COFF a29k-none-coff
2938 AMD 29000 embedded with a.out a29k-none-aout
2940 testsuite/gdb.hp/gdb.threads-hp/ directory
2942 * New command "set max-user-call-depth <nnn>"
2944 This command allows the user to limit the call depth of user-defined
2945 commands. The default is 1024.
2947 * Changes in FreeBSD/i386 native debugging.
2949 Support for the "generate-core-file" has been added.
2951 * New commands "dump", "append", and "restore".
2953 These commands allow data to be copied from target memory
2954 to a bfd-format or binary file (dump and append), and back
2955 from a file into memory (restore).
2957 * Improved "next/step" support on multi-processor Alpha Tru64.
2959 The previous single-step mechanism could cause unpredictable problems,
2960 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2961 of a software single-step mechanism prevents this.
2963 *** Changes in GDB 5.2.1:
2971 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2972 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2973 Fix, by Joel Brobecker imported from mainline.
2975 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2976 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2977 Fix, by Fred Fish, imported from mainline.
2979 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2980 Surprisingly enough, it works now.
2981 By Michal Ludvig, imported from mainline.
2983 i386 hardware watchpoint support:
2984 avoid misses on second run for some targets.
2985 By Pierre Muller, imported from mainline.
2987 *** Changes in GDB 5.2:
2989 * New command "set trust-readonly-sections on[off]".
2991 This command is a hint that tells gdb that read-only sections
2992 really are read-only (ie. that their contents will not change).
2993 In this mode, gdb will go to the object file rather than the
2994 target to read memory from read-only sections (such as ".text").
2995 This can be a significant performance improvement on some
2996 (notably embedded) targets.
2998 * New command "generate-core-file" (or "gcore").
3000 This new gdb command allows the user to drop a core file of the child
3001 process state at any time. So far it's been implemented only for
3002 GNU/Linux and Solaris, but should be relatively easily ported to other
3003 hosts. Argument is core file name (defaults to core.<pid>).
3005 * New command line option
3007 GDB now accepts --pid or -p followed by a process id.
3009 * Change in command line behavior -- corefiles vs. process ids.
3011 There is a subtle behavior in the way in which GDB handles
3012 command line arguments. The first non-flag argument is always
3013 a program to debug, but the second non-flag argument may either
3014 be a corefile or a process id. Previously, GDB would attempt to
3015 open the second argument as a corefile, and if that failed, would
3016 issue a superfluous error message and then attempt to attach it as
3017 a process. Now, if the second argument begins with a non-digit,
3018 it will be treated as a corefile. If it begins with a digit,
3019 GDB will attempt to attach it as a process, and if no such process
3020 is found, will then attempt to open it as a corefile.
3022 * Changes in ARM configurations.
3024 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3025 configuration is fully multi-arch.
3027 * New native configurations
3029 ARM NetBSD arm*-*-netbsd*
3030 x86 OpenBSD i[3456]86-*-openbsd*
3031 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3032 Sparc64 running FreeBSD sparc64-*-freebsd*
3036 Sanyo XStormy16 xstormy16-elf
3038 * OBSOLETE configurations and files
3040 Configurations that have been declared obsolete in this release have
3041 been commented out. Unless there is activity to revive these
3042 configurations, the next release of GDB will have their sources
3043 permanently REMOVED.
3045 AMD 29k family via UDI a29k-amd-udi, udi29k
3046 A29K VxWorks a29k-*-vxworks
3047 AMD 29000 embedded, using EBMON a29k-none-none
3048 AMD 29000 embedded with COFF a29k-none-coff
3049 AMD 29000 embedded with a.out a29k-none-aout
3051 testsuite/gdb.hp/gdb.threads-hp/ directory
3053 * REMOVED configurations and files
3055 TI TMS320C80 tic80-*-*
3057 PowerPC Solaris powerpcle-*-solaris*
3058 PowerPC Windows NT powerpcle-*-cygwin32
3059 PowerPC Netware powerpc-*-netware*
3060 Harris/CXUX m88k m88*-harris-cxux*
3061 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3062 ns32k-utek-sysv* ns32k-utek-*
3063 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3064 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3065 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3066 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3067 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3069 * Changes to command line processing
3071 The new `--args' feature can be used to specify command-line arguments
3072 for the inferior from gdb's command line.
3074 * Changes to key bindings
3076 There is a new `operate-and-get-next' function bound to `C-o'.
3078 *** Changes in GDB 5.1.1
3080 Fix compile problem on DJGPP.
3082 Fix a problem with floating-point registers on the i386 being
3085 Fix to stop GDB crashing on .debug_str debug info.
3087 Numerous documentation fixes.
3089 Numerous testsuite fixes.
3091 *** Changes in GDB 5.1:
3093 * New native configurations
3095 Alpha FreeBSD alpha*-*-freebsd*
3096 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3097 MIPS GNU/Linux mips*-*-linux*
3098 MIPS SGI Irix 6.x mips*-sgi-irix6*
3099 ia64 AIX ia64-*-aix*
3100 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3104 Motorola 68HC11 and 68HC12 m68hc11-elf
3106 UltraSparc running GNU/Linux sparc64-*-linux*
3108 * OBSOLETE configurations and files
3110 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3111 Harris/CXUX m88k m88*-harris-cxux*
3112 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3113 ns32k-utek-sysv* ns32k-utek-*
3114 TI TMS320C80 tic80-*-*
3116 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3117 PowerPC Solaris powerpcle-*-solaris*
3118 PowerPC Windows NT powerpcle-*-cygwin32
3119 PowerPC Netware powerpc-*-netware*
3120 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3121 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3122 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3123 Apple Macintosh (MPW) host N/A
3125 stuff.c (Program to stuff files into a specially prepared space in kdb)
3126 kdb-start.c (Main loop for the standalone kernel debugger)
3128 Configurations that have been declared obsolete in this release have
3129 been commented out. Unless there is activity to revive these
3130 configurations, the next release of GDB will have their sources
3131 permanently REMOVED.
3133 * REMOVED configurations and files
3135 Altos 3068 m68*-altos-*
3136 Convex c1-*-*, c2-*-*
3138 ARM RISCix arm-*-* (as host)
3142 * GDB has been converted to ISO C.
3144 GDB's source code has been converted to ISO C. In particular, the
3145 sources are fully protoized, and rely on standard headers being
3150 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3152 * The MI enabled by default.
3154 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3155 revised and enabled by default. Packages which use GDB as a debugging
3156 engine behind a UI or another front end are encouraged to switch to
3157 using the GDB/MI interface, instead of the old annotations interface
3158 which is now deprecated.
3160 * Support for debugging Pascal programs.
3162 GDB now includes support for debugging Pascal programs. The following
3163 main features are supported:
3165 - Pascal-specific data types such as sets;
3167 - automatic recognition of Pascal sources based on file-name
3170 - Pascal-style display of data types, variables, and functions;
3172 - a Pascal expression parser.
3174 However, some important features are not yet supported.
3176 - Pascal string operations are not supported at all;
3178 - there are some problems with boolean types;
3180 - Pascal type hexadecimal constants are not supported
3181 because they conflict with the internal variables format;
3183 - support for Pascal objects and classes is not full yet;
3185 - unlike Pascal, GDB is case-sensitive for symbol names.
3187 * Changes in completion.
3189 Commands such as `shell', `run' and `set args', which pass arguments
3190 to inferior programs, now complete on file names, similar to what
3191 users expect at the shell prompt.
3193 Commands which accept locations, such as `disassemble', `print',
3194 `breakpoint', `until', etc. now complete on filenames as well as
3195 program symbols. Thus, if you type "break foob TAB", and the source
3196 files linked into the programs include `foobar.c', that file name will
3197 be one of the candidates for completion. However, file names are not
3198 considered for completion after you typed a colon that delimits a file
3199 name from a name of a function in that file, as in "break foo.c:bar".
3201 `set demangle-style' completes on available demangling styles.
3203 * New platform-independent commands:
3205 It is now possible to define a post-hook for a command as well as a
3206 hook that runs before the command. For more details, see the
3207 documentation of `hookpost' in the GDB manual.
3209 * Changes in GNU/Linux native debugging.
3211 Support for debugging multi-threaded programs has been completely
3212 revised for all platforms except m68k and sparc. You can now debug as
3213 many threads as your system allows you to have.
3215 Attach/detach is supported for multi-threaded programs.
3217 Support for SSE registers was added for x86. This doesn't work for
3218 multi-threaded programs though.
3220 * Changes in MIPS configurations.
3222 Multi-arch support is enabled for all MIPS configurations.
3224 GDB can now be built as native debugger on SGI Irix 6.x systems for
3225 debugging n32 executables. (Debugging 64-bit executables is not yet
3228 * Unified support for hardware watchpoints in all x86 configurations.
3230 Most (if not all) native x86 configurations support hardware-assisted
3231 breakpoints and watchpoints in a unified manner. This support
3232 implements debug register sharing between watchpoints, which allows to
3233 put a virtually infinite number of watchpoints on the same address,
3234 and also supports watching regions up to 16 bytes with several debug
3237 The new maintenance command `maintenance show-debug-regs' toggles
3238 debugging print-outs in functions that insert, remove, and test
3239 watchpoints and hardware breakpoints.
3241 * Changes in the DJGPP native configuration.
3243 New command ``info dos sysinfo'' displays assorted information about
3244 the CPU, OS, memory, and DPMI server.
3246 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3247 display information about segment descriptors stored in GDT, LDT, and
3250 New commands ``info dos pde'' and ``info dos pte'' display entries
3251 from Page Directory and Page Tables (for now works with CWSDPMI only).
3252 New command ``info dos address-pte'' displays the Page Table entry for
3253 a given linear address.
3255 GDB can now pass command lines longer than 126 characters to the
3256 program being debugged (requires an update to the libdbg.a library
3257 which is part of the DJGPP development kit).
3259 DWARF2 debug info is now supported.
3261 It is now possible to `step' and `next' through calls to `longjmp'.
3263 * Changes in documentation.
3265 All GDB documentation was converted to GFDL, the GNU Free
3266 Documentation License.
3268 Tracepoints-related commands are now fully documented in the GDB
3271 TUI, the Text-mode User Interface, is now documented in the manual.
3273 Tracepoints-related commands are now fully documented in the GDB
3276 The "GDB Internals" manual now has an index. It also includes
3277 documentation of `ui_out' functions, GDB coding standards, x86
3278 hardware watchpoints, and memory region attributes.
3280 * GDB's version number moved to ``version.in''
3282 The Makefile variable VERSION has been replaced by the file
3283 ``version.in''. People creating GDB distributions should update the
3284 contents of this file.
3288 GUD support is now a standard part of the EMACS distribution.
3290 *** Changes in GDB 5.0:
3292 * Improved support for debugging FP programs on x86 targets
3294 Unified and much-improved support for debugging floating-point
3295 programs on all x86 targets. In particular, ``info float'' now
3296 displays the FP registers in the same format on all x86 targets, with
3297 greater level of detail.
3299 * Improvements and bugfixes in hardware-assisted watchpoints
3301 It is now possible to watch array elements, struct members, and
3302 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3303 on x86 targets no longer erroneously trigger when the address is
3306 * Improvements in the native DJGPP version of GDB
3308 The distribution now includes all the scripts and auxiliary files
3309 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3310 machines ``out of the box''.
3312 The DJGPP version can now debug programs that use signals. It is
3313 possible to catch signals that happened in the debuggee, deliver
3314 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3315 would kill the program being debugged.) Programs that hook hardware
3316 interrupts (keyboard, timer, etc.) can also be debugged.
3318 It is now possible to debug DJGPP programs that redirect their
3319 standard handles or switch them to raw (as opposed to cooked) mode, or
3320 even close them. The command ``run < foo > bar'' works as expected,
3321 and ``info terminal'' reports useful information about the debuggee's
3322 terminal, including raw/cooked mode, redirection, etc.
3324 The DJGPP version now uses termios functions for console I/O, which
3325 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3328 DOS-style file names with drive letters are now fully supported by
3331 It is now possible to debug DJGPP programs that switch their working
3332 directory. It is also possible to rerun the debuggee any number of
3333 times without restarting GDB; thus, you can use the same setup,
3334 breakpoints, etc. for many debugging sessions.
3336 * New native configurations
3338 ARM GNU/Linux arm*-*-linux*
3339 PowerPC GNU/Linux powerpc-*-linux*
3343 Motorola MCore mcore-*-*
3344 x86 VxWorks i[3456]86-*-vxworks*
3345 PowerPC VxWorks powerpc-*-vxworks*
3346 TI TMS320C80 tic80-*-*
3348 * OBSOLETE configurations
3350 Altos 3068 m68*-altos-*
3351 Convex c1-*-*, c2-*-*
3353 ARM RISCix arm-*-* (as host)
3356 Configurations that have been declared obsolete will be commented out,
3357 but the code will be left in place. If there is no activity to revive
3358 these configurations before the next release of GDB, the sources will
3359 be permanently REMOVED.
3361 * Gould support removed
3363 Support for the Gould PowerNode and NP1 has been removed.
3365 * New features for SVR4
3367 On SVR4 native platforms (such as Solaris), if you attach to a process
3368 without first loading a symbol file, GDB will now attempt to locate and
3369 load symbols from the running process's executable file.
3371 * Many C++ enhancements
3373 C++ support has been greatly improved. Overload resolution now works properly
3374 in almost all cases. RTTI support is on the way.
3376 * Remote targets can connect to a sub-program
3378 A popen(3) style serial-device has been added. This device starts a
3379 sub-process (such as a stand-alone simulator) and then communicates
3380 with that. The sub-program to run is specified using the syntax
3381 ``|<program> <args>'' vis:
3383 (gdb) set remotedebug 1
3384 (gdb) target extended-remote |mn10300-elf-sim program-args
3386 * MIPS 64 remote protocol
3388 A long standing bug in the mips64 remote protocol where by GDB
3389 expected certain 32 bit registers (ex SR) to be transfered as 32
3390 instead of 64 bits has been fixed.
3392 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3393 added to provide backward compatibility with older versions of GDB.
3395 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3397 The command ``set remotebinarydownload'' command has been replaced by
3398 ``set remote X-packet''. Other commands in ``set remote'' family
3399 include ``set remote P-packet''.
3401 * Breakpoint commands accept ranges.
3403 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3404 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3405 ``tracepoint passcount'' also accepts a range of tracepoints.
3407 * ``apropos'' command added.
3409 The ``apropos'' command searches through command names and
3410 documentation strings, printing out matches, making it much easier to
3411 try to find a command that does what you are looking for.
3415 A new machine oriented interface (MI) has been added to GDB. This
3416 interface is designed for debug environments running GDB as a separate
3417 process. This is part of the long term libGDB project. See the
3418 "GDB/MI" chapter of the GDB manual for further information. It can be
3419 enabled by configuring with:
3421 .../configure --enable-gdbmi
3423 *** Changes in GDB-4.18:
3425 * New native configurations
3427 HP-UX 10.20 hppa*-*-hpux10.20
3428 HP-UX 11.x hppa*-*-hpux11.0*
3429 M68K GNU/Linux m68*-*-linux*
3433 Fujitsu FR30 fr30-*-elf*
3434 Intel StrongARM strongarm-*-*
3435 Mitsubishi D30V d30v-*-*
3437 * OBSOLETE configurations
3439 Gould PowerNode, NP1 np1-*-*, pn-*-*
3441 Configurations that have been declared obsolete will be commented out,
3442 but the code will be left in place. If there is no activity to revive
3443 these configurations before the next release of GDB, the sources will
3444 be permanently REMOVED.
3448 As a compatibility experiment, GDB's source files buildsym.h and
3449 buildsym.c have been converted to pure standard C, no longer
3450 containing any K&R compatibility code. We believe that all systems in
3451 use today either come with a standard C compiler, or have a GCC port
3452 available. If this is not true, please report the affected
3453 configuration to bug-gdb@gnu.org immediately. See the README file for
3454 information about getting a standard C compiler if you don't have one
3459 GDB now uses readline 2.2.
3461 * set extension-language
3463 You can now control the mapping between filename extensions and source
3464 languages by using the `set extension-language' command. For instance,
3465 you can ask GDB to treat .c files as C++ by saying
3466 set extension-language .c c++
3467 The command `info extensions' lists all of the recognized extensions
3468 and their associated languages.
3470 * Setting processor type for PowerPC and RS/6000
3472 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3473 you can use the `set processor' command to specify what variant of the
3474 PowerPC family you are debugging. The command
3478 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3479 following PowerPC and RS6000 variants:
3481 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3482 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3484 403GC IBM PowerPC 403GC
3485 505 Motorola PowerPC 505
3486 860 Motorola PowerPC 860 or 850
3487 601 Motorola PowerPC 601
3488 602 Motorola PowerPC 602
3489 603 Motorola/IBM PowerPC 603 or 603e
3490 604 Motorola PowerPC 604 or 604e
3491 750 Motorola/IBM PowerPC 750 or 750
3493 At the moment, this command just tells GDB what to name the
3494 special-purpose processor registers. Since almost all the affected
3495 registers are inaccessible to user-level programs, this command is
3496 only useful for remote debugging in its present form.
3500 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3501 more extensive support for HP-UX. Added features include shared
3502 library support, kernel threads and hardware watchpoints for 11.00,
3503 support for HP's ANSI C and C++ compilers, and a compatibility mode
3504 for xdb and dbx commands.
3508 HP's donation includes the new concept of catchpoints, which is a
3509 generalization of the old catch command. On HP-UX, it is now possible
3510 to catch exec, fork, and vfork, as well as library loading.
3512 This means that the existing catch command has changed; its first
3513 argument now specifies the type of catch to be set up. See the
3514 output of "help catch" for a list of catchpoint types.
3516 * Debugging across forks
3518 On HP-UX, you can choose which process to debug when a fork() happens
3523 HP has donated a curses-based terminal user interface (TUI). To get
3524 it, build with --enable-tui. Although this can be enabled for any
3525 configuration, at present it only works for native HP debugging.
3527 * GDB remote protocol additions
3529 A new protocol packet 'X' that writes binary data is now available.
3530 Default behavior is to try 'X', then drop back to 'M' if the stub
3531 fails to respond. The settable variable `remotebinarydownload'
3532 allows explicit control over the use of 'X'.
3534 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3535 full 64-bit address. The command
3537 set remoteaddresssize 32
3539 can be used to revert to the old behaviour. For existing remote stubs
3540 the change should not be noticed, as the additional address information
3543 In order to assist in debugging stubs, you may use the maintenance
3544 command `packet' to send any text string to the stub. For instance,
3546 maint packet heythere
3548 sends the packet "$heythere#<checksum>". Note that it is very easy to
3549 disrupt a debugging session by sending the wrong packet at the wrong
3552 The compare-sections command allows you to compare section data on the
3553 target to what is in the executable file without uploading or
3554 downloading, by comparing CRC checksums.
3556 * Tracing can collect general expressions
3558 You may now collect general expressions at tracepoints. This requires
3559 further additions to the target-side stub; see tracepoint.c and
3560 doc/agentexpr.texi for further details.
3562 * mask-address variable for Mips
3564 For Mips targets, you may control the zeroing of the upper 32 bits of
3565 a 64-bit address by entering `set mask-address on'. This is mainly
3566 of interest to users of embedded R4xxx and R5xxx processors.
3568 * Higher serial baud rates
3570 GDB's serial code now allows you to specify baud rates 57600, 115200,
3571 230400, and 460800 baud. (Note that your host system may not be able
3572 to achieve all of these rates.)
3576 The i960 configuration now includes an initial implementation of a
3577 builtin simulator, contributed by Jim Wilson.
3580 *** Changes in GDB-4.17:
3582 * New native configurations
3584 Alpha GNU/Linux alpha*-*-linux*
3585 Unixware 2.x i[3456]86-unixware2*
3586 Irix 6.x mips*-sgi-irix6*
3587 PowerPC GNU/Linux powerpc-*-linux*
3588 PowerPC Solaris powerpcle-*-solaris*
3589 Sparc GNU/Linux sparc-*-linux*
3590 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3594 Argonaut Risc Chip (ARC) arc-*-*
3595 Hitachi H8/300S h8300*-*-*
3596 Matsushita MN10200 w/simulator mn10200-*-*
3597 Matsushita MN10300 w/simulator mn10300-*-*
3598 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3599 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3600 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3601 Mitsubishi D10V w/simulator d10v-*-*
3602 Mitsubishi M32R/D w/simulator m32r-*-elf*
3603 Tsqware Sparclet sparclet-*-*
3604 NEC V850 w/simulator v850-*-*
3606 * New debugging protocols
3608 ARM with RDI protocol arm*-*-*
3609 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3610 DDB and LSI variants of PMON protocol mips*-*-*
3611 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3612 PowerPC with SDS protocol powerpc{,le}-*-eabi
3613 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3617 All configurations can now understand and use the DWARF 2 debugging
3618 format. The choice is automatic, if the symbol file contains DWARF 2
3623 GDB now includes basic Java language support. This support is
3624 only useful with Java compilers that produce native machine code.
3626 * solib-absolute-prefix and solib-search-path
3628 For SunOS and SVR4 shared libraries, you may now set the prefix for
3629 loading absolute shared library symbol files, and the search path for
3630 locating non-absolute shared library symbol files.
3632 * Live range splitting
3634 GDB can now effectively debug code for which GCC has performed live
3635 range splitting as part of its optimization. See gdb/doc/LRS for
3636 more details on the expected format of the stabs information.
3640 GDB's support for the GNU Hurd, including thread debugging, has been
3641 updated to work with current versions of the Hurd.
3645 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3646 instruction set. ARM GDB automatically detects when Thumb
3647 instructions are in use, and adjusts disassembly and backtracing
3652 GDB's MIPS target configurations now handle the MIP16 16-bit
3657 GDB now includes support for overlays; if an executable has been
3658 linked such that multiple sections are based at the same address, GDB
3659 will decide which section to use for symbolic info. You can choose to
3660 control the decision manually, using overlay commands, or implement
3661 additional target-side support and use "overlay load-target" to bring
3662 in the overlay mapping. Do "help overlay" for more detail.
3666 The command "info symbol <address>" displays information about
3667 the symbol at the specified address.
3671 The standard remote protocol now includes an extension that allows
3672 asynchronous collection and display of trace data. This requires
3673 extensive support in the target-side debugging stub. Tracing mode
3674 includes a new interaction mode in GDB and new commands: see the
3675 file tracepoint.c for more details.
3679 Configurations for embedded MIPS now include a simulator contributed
3680 by Cygnus Solutions. The simulator supports the instruction sets
3681 of most MIPS variants.
3685 Sparc configurations may now include the ERC32 simulator contributed
3686 by the European Space Agency. The simulator is not built into
3687 Sparc targets by default; configure with --enable-sim to include it.
3691 For target configurations that may include multiple variants of a
3692 basic architecture (such as MIPS and SH), you may now set the
3693 architecture explicitly. "set arch" sets, "info arch" lists
3694 the possible architectures.
3696 *** Changes in GDB-4.16:
3698 * New native configurations
3700 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3701 M68K NetBSD m68k-*-netbsd*
3702 PowerPC AIX 4.x powerpc-*-aix*
3703 PowerPC MacOS powerpc-*-macos*
3704 PowerPC Windows NT powerpcle-*-cygwin32
3705 RS/6000 AIX 4.x rs6000-*-aix4*
3709 ARM with RDP protocol arm-*-*
3710 I960 with MON960 i960-*-coff
3711 MIPS VxWorks mips*-*-vxworks*
3712 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3713 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3715 Matra Sparclet sparclet-*-*
3719 The powerpc-eabi configuration now includes the PSIM simulator,
3720 contributed by Andrew Cagney, with assistance from Mike Meissner.
3721 PSIM is a very elaborate model of the PowerPC, including not only
3722 basic instruction set execution, but also details of execution unit
3723 performance and I/O hardware. See sim/ppc/README for more details.
3727 GDB now works with Solaris 2.5.
3729 * Windows 95/NT native
3731 GDB will now work as a native debugger on Windows 95 and Windows NT.
3732 To build it from source, you must use the "gnu-win32" environment,
3733 which uses a DLL to emulate enough of Unix to run the GNU tools.
3734 Further information, binaries, and sources are available at
3735 ftp.cygnus.com, under pub/gnu-win32.
3737 * dont-repeat command
3739 If a user-defined command includes the command `dont-repeat', then the
3740 command will not be repeated if the user just types return. This is
3741 useful if the command is time-consuming to run, so that accidental
3742 extra keystrokes don't run the same command many times.
3744 * Send break instead of ^C
3746 The standard remote protocol now includes an option to send a break
3747 rather than a ^C to the target in order to interrupt it. By default,
3748 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3750 * Remote protocol timeout
3752 The standard remote protocol includes a new variable `remotetimeout'
3753 that allows you to set the number of seconds before GDB gives up trying
3754 to read from the target. The default value is 2.
3756 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3758 By default GDB will automatically keep track of objects as they are
3759 loaded and unloaded by the dynamic linker. By using the command `set
3760 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3761 when shared library events occur, thus allowing you to set breakpoints
3762 in shared libraries which are explicitly loaded by the inferior.
3764 Note this feature does not work on hpux8. On hpux9 you must link
3765 /usr/lib/end.o into your program. This feature should work
3766 automatically on hpux10.
3768 * Irix 5.x hardware watchpoint support
3770 Irix 5 configurations now support the use of hardware watchpoints.
3772 * Mips protocol "SYN garbage limit"
3774 When debugging a Mips target using the `target mips' protocol, you
3775 may set the number of characters that GDB will ignore by setting
3776 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3777 every character. The default value is 1050.
3779 * Recording and replaying remote debug sessions
3781 If you set `remotelogfile' to the name of a file, gdb will write to it
3782 a recording of a remote debug session. This recording may then be
3783 replayed back to gdb using "gdbreplay". See gdbserver/README for
3784 details. This is useful when you have a problem with GDB while doing
3785 remote debugging; you can make a recording of the session and send it
3786 to someone else, who can then recreate the problem.
3788 * Speedups for remote debugging
3790 GDB includes speedups for downloading and stepping MIPS systems using
3791 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3792 and more efficient S-record downloading.
3794 * Memory use reductions and statistics collection
3796 GDB now uses less memory and reports statistics about memory usage.
3797 Try the `maint print statistics' command, for example.
3799 *** Changes in GDB-4.15:
3801 * Psymtabs for XCOFF
3803 The symbol reader for AIX GDB now uses partial symbol tables. This
3804 can greatly improve startup time, especially for large executables.
3806 * Remote targets use caching
3808 Remote targets now use a data cache to speed up communication with the
3809 remote side. The data cache could lead to incorrect results because
3810 it doesn't know about volatile variables, thus making it impossible to
3811 debug targets which use memory mapped I/O devices. `set remotecache
3812 off' turns the the data cache off.
3814 * Remote targets may have threads
3816 The standard remote protocol now includes support for multiple threads
3817 in the target system, using new protocol commands 'H' and 'T'. See
3818 gdb/remote.c for details.
3822 If GDB is configured with `--enable-netrom', then it will include
3823 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3824 acts as though it is a bank of ROM on the target board, but you can
3825 write into it over the network. GDB's support consists only of
3826 support for fast loading into the emulated ROM; to debug, you must use
3827 another protocol, such as standard remote protocol. The usual
3828 sequence is something like
3830 target nrom <netrom-hostname>
3832 target remote <netrom-hostname>:1235
3836 GDB now includes support for the Apple Macintosh, as a host only. It
3837 may be run as either an MPW tool or as a standalone application, and
3838 it can debug through the serial port. All the usual GDB commands are
3839 available, but to the target command, you must supply "serial" as the
3840 device type instead of "/dev/ttyXX". See mpw-README in the main
3841 directory for more information on how to build. The MPW configuration
3842 scripts */mpw-config.in support only a few targets, and only the
3843 mips-idt-ecoff target has been tested.
3847 GDB configuration now uses autoconf. This is not user-visible,
3848 but does simplify configuration and building.
3852 GDB now supports hpux10.
3854 *** Changes in GDB-4.14:
3856 * New native configurations
3858 x86 FreeBSD i[345]86-*-freebsd
3859 x86 NetBSD i[345]86-*-netbsd
3860 NS32k NetBSD ns32k-*-netbsd
3861 Sparc NetBSD sparc-*-netbsd
3865 A29K VxWorks a29k-*-vxworks
3866 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3867 CPU32 EST-300 emulator m68*-*-est*
3868 PowerPC ELF powerpc-*-elf
3871 * Alpha OSF/1 support for procfs
3873 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3874 possible to attach to running processes. As the mounting of the /proc
3875 filesystem is optional on the Alpha, GDB automatically determines
3876 the availability of /proc during startup. This can lead to problems
3877 if /proc is unmounted after GDB has been started.
3879 * Arguments to user-defined commands
3881 User commands may accept up to 10 arguments separated by whitespace.
3882 Arguments are accessed within the user command via $arg0..$arg9. A
3885 print $arg0 + $arg1 + $arg2
3887 To execute the command use:
3890 Defines the command "adder" which prints the sum of its three arguments.
3891 Note the arguments are text substitutions, so they may reference variables,
3892 use complex expressions, or even perform inferior function calls.
3894 * New `if' and `while' commands
3896 This makes it possible to write more sophisticated user-defined
3897 commands. Both commands take a single argument, which is the
3898 expression to evaluate, and must be followed by the commands to
3899 execute, one per line, if the expression is nonzero, the list being
3900 terminated by the word `end'. The `if' command list may include an
3901 `else' word, which causes the following commands to be executed only
3902 if the expression is zero.
3904 * Fortran source language mode
3906 GDB now includes partial support for Fortran 77. It will recognize
3907 Fortran programs and can evaluate a subset of Fortran expressions, but
3908 variables and functions may not be handled correctly. GDB will work
3909 with G77, but does not yet know much about symbols emitted by other
3912 * Better HPUX support
3914 Most debugging facilities now work on dynamic executables for HPPAs
3915 running hpux9 or later. You can attach to running dynamically linked
3916 processes, but by default the dynamic libraries will be read-only, so
3917 for instance you won't be able to put breakpoints in them. To change
3918 that behavior do the following before running the program:
3924 This will cause the libraries to be mapped private and read-write.
3925 To revert to the normal behavior, do this:
3931 You cannot set breakpoints or examine data in the library until after
3932 the library is loaded if the function/data symbols do not have
3935 GDB can now also read debug symbols produced by the HP C compiler on
3936 HPPAs (sorry, no C++, Fortran or 68k support).
3938 * Target byte order now dynamically selectable
3940 You can choose which byte order to use with a target system, via the
3941 commands "set endian big" and "set endian little", and you can see the
3942 current setting by using "show endian". You can also give the command
3943 "set endian auto", in which case GDB will use the byte order
3944 associated with the executable. Currently, only embedded MIPS
3945 configurations support dynamic selection of target byte order.
3947 * New DOS host serial code
3949 This version uses DPMI interrupts to handle buffered I/O, so you
3950 no longer need to run asynctsr when debugging boards connected to
3953 *** Changes in GDB-4.13:
3955 * New "complete" command
3957 This lists all the possible completions for the rest of the line, if it
3958 were to be given as a command itself. This is intended for use by emacs.
3960 * Trailing space optional in prompt
3962 "set prompt" no longer adds a space for you after the prompt you set. This
3963 allows you to set a prompt which ends in a space or one that does not.
3965 * Breakpoint hit counts
3967 "info break" now displays a count of the number of times the breakpoint
3968 has been hit. This is especially useful in conjunction with "ignore"; you
3969 can ignore a large number of breakpoint hits, look at the breakpoint info
3970 to see how many times the breakpoint was hit, then run again, ignoring one
3971 less than that number, and this will get you quickly to the last hit of
3974 * Ability to stop printing at NULL character
3976 "set print null-stop" will cause GDB to stop printing the characters of
3977 an array when the first NULL is encountered. This is useful when large
3978 arrays actually contain only short strings.
3980 * Shared library breakpoints
3982 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3983 breakpoints in shared libraries before the executable is run.
3985 * Hardware watchpoints
3987 There is a new hardware breakpoint for the watch command for sparclite
3988 targets. See gdb/sparclite/hw_breakpoint.note.
3990 Hardware watchpoints are also now supported under GNU/Linux.
3994 Annotations have been added. These are for use with graphical interfaces,
3995 and are still experimental. Currently only gdba.el uses these.
3997 * Improved Irix 5 support
3999 GDB now works properly with Irix 5.2.
4001 * Improved HPPA support
4003 GDB now works properly with the latest GCC and GAS.
4005 * New native configurations
4007 Sequent PTX4 i[34]86-sequent-ptx4
4008 HPPA running OSF/1 hppa*-*-osf*
4009 Atari TT running SVR4 m68*-*-sysv4*
4010 RS/6000 LynxOS rs6000-*-lynxos*
4014 OS/9000 i[34]86-*-os9k
4015 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4018 * Hitachi SH7000 and E7000-PC ICE support
4020 There is now support for communicating with the Hitachi E7000-PC ICE.
4021 This is available automatically when GDB is configured for the SH.
4025 As usual, a variety of small fixes and improvements, both generic
4026 and configuration-specific. See the ChangeLog for more detail.
4028 *** Changes in GDB-4.12:
4030 * Irix 5 is now supported
4034 GDB-4.12 on the HPPA has a number of changes which make it unable
4035 to debug the output from the currently released versions of GCC and
4036 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4037 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4038 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4041 *** Changes in GDB-4.11:
4043 * User visible changes:
4047 The "set remotedebug" option is now consistent between the mips remote
4048 target, remote targets using the gdb-specific protocol, UDI (AMD's
4049 debug protocol for the 29k) and the 88k bug monitor. It is now an
4050 integer specifying a debug level (normally 0 or 1, but 2 means more
4051 debugging info for the mips target).
4053 * DEC Alpha native support
4055 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4056 debug info, but GDB works fairly well with the DEC compiler and should
4057 work with a future GCC release. See the README file for a few
4058 Alpha-specific notes.
4060 * Preliminary thread implementation
4062 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4064 * LynxOS native and target support for 386
4066 This release has been hosted on LynxOS 2.2, and also can be configured
4067 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4070 * Improvements in C++ mangling/demangling.
4072 This release has much better g++ debugging, specifically in name
4073 mangling/demangling, virtual function calls, print virtual table,
4074 call methods, ...etc.
4076 *** Changes in GDB-4.10:
4078 * User visible changes:
4080 Remote debugging using the GDB-specific (`target remote') protocol now
4081 supports the `load' command. This is only useful if you have some
4082 other way of getting the stub to the target system, and you can put it
4083 somewhere in memory where it won't get clobbered by the download.
4085 Filename completion now works.
4087 When run under emacs mode, the "info line" command now causes the
4088 arrow to point to the line specified. Also, "info line" prints
4089 addresses in symbolic form (as well as hex).
4091 All vxworks based targets now support a user settable option, called
4092 vxworks-timeout. This option represents the number of seconds gdb
4093 should wait for responses to rpc's. You might want to use this if
4094 your vxworks target is, perhaps, a slow software simulator or happens
4095 to be on the far side of a thin network line.
4099 This release contains support for using a DEC alpha as a GDB host for
4100 cross debugging. Native alpha debugging is not supported yet.
4103 *** Changes in GDB-4.9:
4107 This is the first GDB release which is accompanied by a matching testsuite.
4108 The testsuite requires installation of dejagnu, which should be available
4109 via ftp from most sites that carry GNU software.
4113 'Cfront' style demangling has had its name changed to 'ARM' style, to
4114 emphasize that it was written from the specifications in the C++ Annotated
4115 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4116 disclaimers, it still generated too much confusion with users attempting to
4117 use gdb with AT&T cfront.
4121 GDB now uses a standard remote interface to a simulator library.
4122 So far, the library contains simulators for the Zilog Z8001/2, the
4123 Hitachi H8/300, H8/500 and Super-H.
4125 * New targets supported
4127 H8/300 simulator h8300-hitachi-hms or h8300hms
4128 H8/500 simulator h8500-hitachi-hms or h8500hms
4129 SH simulator sh-hitachi-hms or sh
4130 Z8000 simulator z8k-zilog-none or z8ksim
4131 IDT MIPS board over serial line mips-idt-ecoff
4133 Cross-debugging to GO32 targets is supported. It requires a custom
4134 version of the i386-stub.c module which is integrated with the
4135 GO32 memory extender.
4137 * New remote protocols
4139 MIPS remote debugging protocol.
4141 * New source languages supported
4143 This version includes preliminary support for Chill, a Pascal like language
4144 used by telecommunications companies. Chill support is also being integrated
4145 into the GNU compiler, but we don't know when it will be publically available.
4148 *** Changes in GDB-4.8:
4150 * HP Precision Architecture supported
4152 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4153 version of this support was available as a set of patches from the
4154 University of Utah. GDB does not support debugging of programs
4155 compiled with the HP compiler, because HP will not document their file
4156 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4157 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4159 Many problems in the preliminary version have been fixed.
4161 * Faster and better demangling
4163 We have improved template demangling and fixed numerous bugs in the GNU style
4164 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4165 character types (wchar_t) are now supported. Demangling of each symbol is now
4166 only done once, and is cached when the symbol table for a file is read in.
4167 This results in a small increase in memory usage for C programs, a moderate
4168 increase in memory usage for C++ programs, and a fantastic speedup in
4171 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4172 from the specifications in the Annotated Reference Manual, which AT&T's
4173 compiler does not actually implement.
4175 * G++ multiple inheritance compiler problem
4177 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4178 inheritance lattices was reworked to properly discover ambiguities. We
4179 recently found an example which causes this new algorithm to fail in a
4180 very subtle way, producing bad debug information for those classes.
4181 The file 'gcc.patch' (in this directory) can be applied to gcc to
4182 circumvent the problem. A future GCC release will contain a complete
4185 The previous G++ debug info problem (mentioned below for the gdb-4.7
4186 release) is fixed in gcc version 2.3.2.
4188 * Improved configure script
4190 The `configure' script will now attempt to guess your system type if
4191 you don't supply a host system type. The old scheme of supplying a
4192 host system triplet is preferable over using this. All the magic is
4193 done in the new `config.guess' script. Examine it for details.
4195 We have also brought our configure script much more in line with the FSF's
4196 version. It now supports the --with-xxx options. In particular,
4197 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4198 The resulting GDB will not be able to read arbitrary object file formats --
4199 only the format ``expected'' to be used on the configured target system.
4200 We hope to make this the default in a future release.
4202 * Documentation improvements
4204 There's new internal documentation on how to modify GDB, and how to
4205 produce clean changes to the code. We implore people to read it
4206 before submitting changes.
4208 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4209 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4210 `info' files are also provided. To build `info' files from scratch,
4211 you will need the latest `makeinfo' release, which will be available in
4212 a future texinfo-X.Y release.
4214 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4215 We're not sure exactly which versions have this problem, but it has
4216 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4217 or better. If that isn't possible, there is a patch in
4218 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4219 around this problem.
4223 GDB now supports array constants that can be used in expressions typed in by
4224 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4225 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4228 The new directory `gdb/sparclite' contains a program that demonstrates
4229 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4231 * New native hosts supported
4233 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4234 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4236 * New targets supported
4238 AMD 29k family via UDI a29k-amd-udi or udi29k
4240 * New file formats supported
4242 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4243 HPUX core files, and SCO 3.2v2 core files.
4247 Attaching to processes now works again; thanks for the many bug reports.
4249 We have also stomped on a bunch of core dumps caused by
4250 printf_filtered("%s") problems.
4252 We eliminated a copyright problem on the rpc and ptrace header files
4253 for VxWorks, which was discovered at the last minute during the 4.7
4254 release. You should now be able to build a VxWorks GDB.
4256 You can now interrupt gdb while an attached process is running. This
4257 will cause the attached process to stop, and give control back to GDB.
4259 We fixed problems caused by using too many file descriptors
4260 for reading symbols from object files and libraries. This was
4261 especially a problem for programs that used many (~100) shared
4264 The `step' command now only enters a subroutine if there is line number
4265 information for the subroutine. Otherwise it acts like the `next'
4266 command. Previously, `step' would enter subroutines if there was
4267 any debugging information about the routine. This avoids problems
4268 when using `cc -g1' on MIPS machines.
4270 * Internal improvements
4272 GDB's internal interfaces have been improved to make it easier to support
4273 debugging of multiple languages in the future.
4275 GDB now uses a common structure for symbol information internally.
4276 Minimal symbols (derived from linkage symbols in object files), partial
4277 symbols (from a quick scan of debug information), and full symbols
4278 contain a common subset of information, making it easier to write
4279 shared code that handles any of them.
4281 * New command line options
4283 We now accept --silent as an alias for --quiet.
4287 The memory-mapped-malloc library is now licensed under the GNU Library
4288 General Public License.
4290 *** Changes in GDB-4.7:
4292 * Host/native/target split
4294 GDB has had some major internal surgery to untangle the support for
4295 hosts and remote targets. Now, when you configure GDB for a remote
4296 target, it will no longer load in all of the support for debugging
4297 local programs on the host. When fully completed and tested, this will
4298 ensure that arbitrary host/target combinations are possible.
4300 The primary conceptual shift is to separate the non-portable code in
4301 GDB into three categories. Host specific code is required any time GDB
4302 is compiled on that host, regardless of the target. Target specific
4303 code relates to the peculiarities of the target, but can be compiled on
4304 any host. Native specific code is everything else: it can only be
4305 built when the host and target are the same system. Child process
4306 handling and core file support are two common `native' examples.
4308 GDB's use of /proc for controlling Unix child processes is now cleaner.
4309 It has been split out into a single module under the `target_ops' vector,
4310 plus two native-dependent functions for each system that uses /proc.
4312 * New hosts supported
4314 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4315 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4316 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4318 * New targets supported
4320 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4321 68030 and CPU32 m68030-*-*, m68332-*-*
4323 * New native hosts supported
4325 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4326 (386bsd is not well tested yet)
4327 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4329 * New file formats supported
4331 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4332 supports reading of `a.out.adobe' object files, which are an a.out
4333 format extended with minimal information about multiple sections.
4337 `show copying' is the same as the old `info copying'.
4338 `show warranty' is the same as `info warrantee'.
4339 These were renamed for consistency. The old commands continue to work.
4341 `info handle' is a new alias for `info signals'.
4343 You can now define pre-command hooks, which attach arbitrary command
4344 scripts to any command. The commands in the hook will be executed
4345 prior to the user's command. You can also create a hook which will be
4346 executed whenever the program stops. See gdb.texinfo.
4350 We now deal with Cfront style name mangling, and can even extract type
4351 info from mangled symbols. GDB can automatically figure out which
4352 symbol mangling style your C++ compiler uses.
4354 Calling of methods and virtual functions has been improved as well.
4358 The crash that occured when debugging Sun Ansi-C compiled binaries is
4359 fixed. This was due to mishandling of the extra N_SO stabs output
4362 We also finally got Ultrix 4.2 running in house, and fixed core file
4363 support, with help from a dozen people on the net.
4365 John M. Farrell discovered that the reason that single-stepping was so
4366 slow on all of the Mips based platforms (primarily SGI and DEC) was
4367 that we were trying to demangle and lookup a symbol used for internal
4368 purposes on every instruction that was being stepped through. Changing
4369 the name of that symbol so that it couldn't be mistaken for a C++
4370 mangled symbol sped things up a great deal.
4372 Rich Pixley sped up symbol lookups in general by getting much smarter
4373 about when C++ symbol mangling is necessary. This should make symbol
4374 completion (TAB on the command line) much faster. It's not as fast as
4375 we'd like, but it's significantly faster than gdb-4.6.
4379 A new user controllable variable 'call_scratch_address' can
4380 specify the location of a scratch area to be used when GDB
4381 calls a function in the target. This is necessary because the
4382 usual method of putting the scratch area on the stack does not work
4383 in systems that have separate instruction and data spaces.
4385 We integrated changes to support the 29k UDI (Universal Debugger
4386 Interface), but discovered at the last minute that we didn't have all
4387 of the appropriate copyright paperwork. We are working with AMD to
4388 resolve this, and hope to have it available soon.
4392 We have sped up the remote serial line protocol, especially for targets
4393 with lots of registers. It now supports a new `expedited status' ('T')
4394 message which can be used in place of the existing 'S' status message.
4395 This allows the remote stub to send only the registers that GDB
4396 needs to make a quick decision about single-stepping or conditional
4397 breakpoints, eliminating the need to fetch the entire register set for
4398 each instruction being stepped through.
4400 The GDB remote serial protocol now implements a write-through cache for
4401 registers, only re-reading the registers if the target has run.
4403 There is also a new remote serial stub for SPARC processors. You can
4404 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4405 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4406 processor with a serial port.
4410 Configure.in files have become much easier to read and modify. A new
4411 `table driven' format makes it more obvious what configurations are
4412 supported, and what files each one uses.
4416 There is a new opcodes library which will eventually contain all of the
4417 disassembly routines and opcode tables. At present, it only contains
4418 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4419 disassembler (binutils/objdump) to share these routines.
4421 The libiberty library is now copylefted under the GNU Library General
4422 Public License. This allows more liberal use, and was done so libg++
4423 can use it. This makes no difference to GDB, since the Library License
4424 grants all the rights from the General Public License.
4428 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4429 reference to the stabs symbol info used by the debugger. It is (as far
4430 as we know) the only published document on this fascinating topic. We
4431 encourage you to read it, compare it to the stabs information on your
4432 system, and send improvements on the document in general (to
4433 bug-gdb@prep.ai.mit.edu).
4435 And, of course, many bugs have been fixed.
4438 *** Changes in GDB-4.6:
4440 * Better support for C++ function names
4442 GDB now accepts as input the "demangled form" of C++ overloaded function
4443 names and member function names, and can do command completion on such names
4444 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4445 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4446 Make use of command completion, it is your friend.
4448 GDB also now accepts a variety of C++ mangled symbol formats. They are
4449 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4450 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4451 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4452 for the list of formats.
4454 * G++ symbol mangling problem
4456 Recent versions of gcc have a bug in how they emit debugging information for
4457 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4458 directory) can be applied to gcc to fix the problem. Alternatively, if you
4459 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4460 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4461 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4464 * New 'maintenance' command
4466 All of the commands related to hacking GDB internals have been moved out of
4467 the main command set, and now live behind the 'maintenance' command. This
4468 can also be abbreviated as 'mt'. The following changes were made:
4470 dump-me -> maintenance dump-me
4471 info all-breakpoints -> maintenance info breakpoints
4472 printmsyms -> maintenance print msyms
4473 printobjfiles -> maintenance print objfiles
4474 printpsyms -> maintenance print psymbols
4475 printsyms -> maintenance print symbols
4477 The following commands are new:
4479 maintenance demangle Call internal GDB demangler routine to
4480 demangle a C++ link name and prints the result.
4481 maintenance print type Print a type chain for a given symbol
4483 * Change to .gdbinit file processing
4485 We now read the $HOME/.gdbinit file before processing the argv arguments
4486 (e.g. reading symbol files or core files). This allows global parameters to
4487 be set, which will apply during the symbol reading. The ./.gdbinit is still
4488 read after argv processing.
4490 * New hosts supported
4492 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4494 GNU/Linux support i386-unknown-linux or linux
4496 We are also including code to support the HP/PA running BSD and HPUX. This
4497 is almost guaranteed not to work, as we didn't have time to test or build it
4498 for this release. We are including it so that the more adventurous (or
4499 masochistic) of you can play with it. We also had major problems with the
4500 fact that the compiler that we got from HP doesn't support the -g option.
4503 * New targets supported
4505 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4507 * More smarts about finding #include files
4509 GDB now remembers the compilation directory for all include files, and for
4510 all files from which C is generated (like yacc and lex sources). This
4511 greatly improves GDB's ability to find yacc/lex sources, and include files,
4512 especially if you are debugging your program from a directory different from
4513 the one that contains your sources.
4515 We also fixed a bug which caused difficulty with listing and setting
4516 breakpoints in include files which contain C code. (In the past, you had to
4517 try twice in order to list an include file that you hadn't looked at before.)
4519 * Interesting infernals change
4521 GDB now deals with arbitrary numbers of sections, where the symbols for each
4522 section must be relocated relative to that section's landing place in the
4523 target's address space. This work was needed to support ELF with embedded
4524 stabs used by Solaris-2.0.
4526 * Bug fixes (of course!)
4528 There have been loads of fixes for the following things:
4529 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4530 i960, stabs, DOS(GO32), procfs, etc...
4532 See the ChangeLog for details.
4534 *** Changes in GDB-4.5:
4536 * New machines supported (host and target)
4538 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4540 SGI Irix-4.x mips-sgi-irix4 or iris4
4542 * New malloc package
4544 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4545 Mmalloc is capable of handling mutiple heaps of memory. It is also
4546 capable of saving a heap to a file, and then mapping it back in later.
4547 This can be used to greatly speedup the startup of GDB by using a
4548 pre-parsed symbol table which lives in a mmalloc managed heap. For
4549 more details, please read mmalloc/mmalloc.texi.
4553 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4554 'help info proc' for details.
4556 * MIPS ecoff symbol table format
4558 The code that reads MIPS symbol table format is now supported on all hosts.
4559 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4562 * File name changes for MS-DOS
4564 Many files in the config directories have been renamed to make it easier to
4565 support GDB on MS-DOSe systems (which have very restrictive file name
4566 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4567 environment) is close to working but has some remaining problems. Note
4568 that debugging of DOS programs is not supported, due to limitations
4569 in the ``operating system'', but it can be used to host cross-debugging.
4571 * Cross byte order fixes
4573 Many fixes have been made to support cross debugging of Sparc and MIPS
4574 targets from hosts whose byte order differs.
4576 * New -mapped and -readnow options
4578 If memory-mapped files are available on your system through the 'mmap'
4579 system call, you can use the -mapped option on the `file' or
4580 `symbol-file' commands to cause GDB to write the symbols from your
4581 program into a reusable file. If the program you are debugging is
4582 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4583 Future GDB debugging sessions will notice the presence of this file,
4584 and will quickly map in symbol information from it, rather than reading
4585 the symbol table from the executable program. Using the '-mapped'
4586 option in a GDB `file' or `symbol-file' command has the same effect as
4587 starting GDB with the '-mapped' command-line option.
4589 You can cause GDB to read the entire symbol table immediately by using
4590 the '-readnow' option with any of the commands that load symbol table
4591 information (or on the GDB command line). This makes the command
4592 slower, but makes future operations faster.
4594 The -mapped and -readnow options are typically combined in order to
4595 build a `fred.syms' file that contains complete symbol information.
4596 A simple GDB invocation to do nothing but build a `.syms' file for future
4599 gdb -batch -nx -mapped -readnow programname
4601 The `.syms' file is specific to the host machine on which GDB is run.
4602 It holds an exact image of GDB's internal symbol table. It cannot be
4603 shared across multiple host platforms.
4605 * longjmp() handling
4607 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4608 siglongjmp() without losing control. This feature has not yet been ported to
4609 all systems. It currently works on many 386 platforms, all MIPS-based
4610 platforms (SGI, DECstation, etc), and Sun3/4.
4614 Preliminary work has been put in to support the new Solaris OS from Sun. At
4615 this time, it can control and debug processes, but it is not capable of
4620 As always, many many bug fixes. The major areas were with g++, and mipsread.
4621 People using the MIPS-based platforms should experience fewer mysterious
4622 crashes and trashed symbol tables.
4624 *** Changes in GDB-4.4:
4626 * New machines supported (host and target)
4628 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4630 BSD Reno on Vax vax-dec-bsd
4631 Ultrix on Vax vax-dec-ultrix
4633 * New machines supported (target)
4635 AMD 29000 embedded, using EBMON a29k-none-none
4639 GDB continues to improve its handling of C++. `References' work better.
4640 The demangler has also been improved, and now deals with symbols mangled as
4641 per the Annotated C++ Reference Guide.
4643 GDB also now handles `stabs' symbol information embedded in MIPS
4644 `ecoff' symbol tables. Since the ecoff format was not easily
4645 extensible to handle new languages such as C++, this appeared to be a
4646 good way to put C++ debugging info into MIPS binaries. This option
4647 will be supported in the GNU C compiler, version 2, when it is
4650 * New features for SVR4
4652 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4653 shared libraries. Debugging dynamically linked programs should present
4654 only minor differences from debugging statically linked programs.
4656 The `info proc' command will print out information about any process
4657 on an SVR4 system (including the one you are debugging). At the moment,
4658 it prints the address mappings of the process.
4660 If you bring up GDB on another SVR4 system, please send mail to
4661 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4663 * Better dynamic linking support in SunOS
4665 Reading symbols from shared libraries which contain debugging symbols
4666 now works properly. However, there remain issues such as automatic
4667 skipping of `transfer vector' code during function calls, which
4668 make it harder to debug code in a shared library, than to debug the
4669 same code linked statically.
4673 GDB is now using the latest `getopt' routines from the FSF. This
4674 version accepts the -- prefix for options with long names. GDB will
4675 continue to accept the old forms (-option and +option) as well.
4676 Various single letter abbreviations for options have been explicity
4677 added to the option table so that they won't get overshadowed in the
4678 future by other options that begin with the same letter.
4682 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4683 Many assorted bugs have been handled. Many more remain to be handled.
4684 See the various ChangeLog files (primarily in gdb and bfd) for details.
4687 *** Changes in GDB-4.3:
4689 * New machines supported (host and target)
4691 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4692 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4693 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4695 * Almost SCO Unix support
4697 We had hoped to support:
4698 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4699 (except for core file support), but we discovered very late in the release
4700 that it has problems with process groups that render gdb unusable. Sorry
4701 about that. I encourage people to fix it and post the fixes.
4703 * Preliminary ELF and DWARF support
4705 GDB can read ELF object files on System V Release 4, and can handle
4706 debugging records for C, in DWARF format, in ELF files. This support
4707 is preliminary. If you bring up GDB on another SVR4 system, please
4708 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4713 GDB now uses the latest `readline' library. One user-visible change
4714 is that two tabs will list possible command completions, which previously
4715 required typing M-? (meta-question mark, or ESC ?).
4719 The `stepi' bug that many of you noticed has been squashed.
4720 Many bugs in C++ have been handled. Many more remain to be handled.
4721 See the various ChangeLog files (primarily in gdb and bfd) for details.
4723 * State of the MIPS world (in case you wondered):
4725 GDB can understand the symbol tables emitted by the compilers
4726 supplied by most vendors of MIPS-based machines, including DEC. These
4727 symbol tables are in a format that essentially nobody else uses.
4729 Some versions of gcc come with an assembler post-processor called
4730 mips-tfile. This program is required if you want to do source-level
4731 debugging of gcc-compiled programs. I believe FSF does not ship
4732 mips-tfile with gcc version 1, but it will eventually come with gcc
4735 Debugging of g++ output remains a problem. g++ version 1.xx does not
4736 really support it at all. (If you're lucky, you should be able to get
4737 line numbers and stack traces to work, but no parameters or local
4738 variables.) With some work it should be possible to improve the
4741 When gcc version 2 is released, you will have somewhat better luck.
4742 However, even then you will get confusing results for inheritance and
4745 We will eventually provide full debugging of g++ output on
4746 DECstations. This will probably involve some kind of stabs-in-ecoff
4747 encapulation, but the details have not been worked out yet.
4750 *** Changes in GDB-4.2:
4752 * Improved configuration
4754 Only one copy of `configure' exists now, and it is not self-modifying.
4755 Porting BFD is simpler.
4759 The `step' and `next' commands now only stop at the first instruction
4760 of a source line. This prevents the multiple stops that used to occur
4761 in switch statements, for-loops, etc. `Step' continues to stop if a
4762 function that has debugging information is called within the line.
4766 Lots of small bugs fixed. More remain.
4768 * New host supported (not target)
4770 Intel 386 PC clone running Mach i386-none-mach
4773 *** Changes in GDB-4.1:
4775 * Multiple source language support
4777 GDB now has internal scaffolding to handle several source languages.
4778 It determines the type of each source file from its filename extension,
4779 and will switch expression parsing and number formatting to match the
4780 language of the function in the currently selected stack frame.
4781 You can also specifically set the language to be used, with
4782 `set language c' or `set language modula-2'.
4786 GDB now has preliminary support for the GNU Modula-2 compiler,
4787 currently under development at the State University of New York at
4788 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4789 continue through the fall of 1991 and into 1992.
4791 Other Modula-2 compilers are currently not supported, and attempting to
4792 debug programs compiled with them will likely result in an error as the
4793 symbol table is read. Feel free to work on it, though!
4795 There are hooks in GDB for strict type checking and range checking,
4796 in the `Modula-2 philosophy', but they do not currently work.
4800 GDB can now write to executable and core files (e.g. patch
4801 a variable's value). You must turn this switch on, specify
4802 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4803 by assigning a new value to a variable. Modifications take
4806 * Automatic SunOS shared library reading
4808 When you run your program, GDB automatically determines where its
4809 shared libraries (if any) have been loaded, and reads their symbols.
4810 The `share' command is no longer needed. This also works when
4811 examining core files.
4815 You can specify the number of lines that the `list' command shows.
4818 * New machines supported (host and target)
4820 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4821 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4822 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4824 * New hosts supported (not targets)
4826 IBM RT/PC: romp-ibm-aix or rtpc
4828 * New targets supported (not hosts)
4830 AMD 29000 embedded with COFF a29k-none-coff
4831 AMD 29000 embedded with a.out a29k-none-aout
4832 Ultracomputer remote kernel debug a29k-nyu-kern
4834 * New remote interfaces
4840 *** Changes in GDB-4.0:
4844 Wide output is wrapped at good places to make the output more readable.
4846 Gdb now supports cross-debugging from a host machine of one type to a
4847 target machine of another type. Communication with the target system
4848 is over serial lines. The ``target'' command handles connecting to the
4849 remote system; the ``load'' command will download a program into the
4850 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4851 also supports debugging of realtime processes running under VxWorks,
4852 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4853 stub on the target system.
4855 New CPUs supported include the AMD 29000 and Intel 960.
4857 GDB now reads object files and symbol tables via a ``binary file''
4858 library, which allows a single copy of GDB to debug programs of multiple
4859 object file types such as a.out and coff.
4861 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4862 refcard.dvi and refcard.ps are available to format it).
4865 * Control-Variable user interface simplified
4867 All variables that control the operation of the debugger can be set
4868 by the ``set'' command, and displayed by the ``show'' command.
4870 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4871 ``Show prompt'' produces the response:
4872 Gdb's prompt is new-gdb=>.
4874 What follows are the NEW set commands. The command ``help set'' will
4875 print a complete list of old and new set commands. ``help set FOO''
4876 will give a longer description of the variable FOO. ``show'' will show
4877 all of the variable descriptions and their current settings.
4879 confirm on/off: Enables warning questions for operations that are
4880 hard to recover from, e.g. rerunning the program while
4881 it is already running. Default is ON.
4883 editing on/off: Enables EMACS style command line editing
4884 of input. Previous lines can be recalled with
4885 control-P, the current line can be edited with control-B,
4886 you can search for commands with control-R, etc.
4889 history filename NAME: NAME is where the gdb command history
4890 will be stored. The default is .gdb_history,
4891 or the value of the environment variable
4894 history size N: The size, in commands, of the command history. The
4895 default is 256, or the value of the environment variable
4898 history save on/off: If this value is set to ON, the history file will
4899 be saved after exiting gdb. If set to OFF, the
4900 file will not be saved. The default is OFF.
4902 history expansion on/off: If this value is set to ON, then csh-like
4903 history expansion will be performed on
4904 command line input. The default is OFF.
4906 radix N: Sets the default radix for input and output. It can be set
4907 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4908 in the current radix, so "set radix 10" is always a no-op.
4910 height N: This integer value is the number of lines on a page. Default
4911 is 24, the current `stty rows'' setting, or the ``li#''
4912 setting from the termcap entry matching the environment
4915 width N: This integer value is the number of characters on a line.
4916 Default is 80, the current `stty cols'' setting, or the ``co#''
4917 setting from the termcap entry matching the environment
4920 Note: ``set screensize'' is obsolete. Use ``set height'' and
4921 ``set width'' instead.
4923 print address on/off: Print memory addresses in various command displays,
4924 such as stack traces and structure values. Gdb looks
4925 more ``symbolic'' if you turn this off; it looks more
4926 ``machine level'' with it on. Default is ON.
4928 print array on/off: Prettyprint arrays. New convenient format! Default
4931 print demangle on/off: Print C++ symbols in "source" form if on,
4934 print asm-demangle on/off: Same, for assembler level printouts
4937 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4940 * Support for Epoch Environment.
4942 The epoch environment is a version of Emacs v18 with windowing. One
4943 new command, ``inspect'', is identical to ``print'', except that if you
4944 are running in the epoch environment, the value is printed in its own
4948 * Support for Shared Libraries
4950 GDB can now debug programs and core files that use SunOS shared libraries.
4951 Symbols from a shared library cannot be referenced
4952 before the shared library has been linked with the program (this
4953 happens after you type ``run'' and before the function main() is entered).
4954 At any time after this linking (including when examining core files
4955 from dynamically linked programs), gdb reads the symbols from each
4956 shared library when you type the ``sharedlibrary'' command.
4957 It can be abbreviated ``share''.
4959 sharedlibrary REGEXP: Load shared object library symbols for files
4960 matching a unix regular expression. No argument
4961 indicates to load symbols for all shared libraries.
4963 info sharedlibrary: Status of loaded shared libraries.
4968 A watchpoint stops execution of a program whenever the value of an
4969 expression changes. Checking for this slows down execution
4970 tremendously whenever you are in the scope of the expression, but is
4971 quite useful for catching tough ``bit-spreader'' or pointer misuse
4972 problems. Some machines such as the 386 have hardware for doing this
4973 more quickly, and future versions of gdb will use this hardware.
4975 watch EXP: Set a watchpoint (breakpoint) for an expression.
4977 info watchpoints: Information about your watchpoints.
4979 delete N: Deletes watchpoint number N (same as breakpoints).
4980 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4981 enable N: Re-enables watchpoint number N (same as breakpoints).
4984 * C++ multiple inheritance
4986 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4989 * C++ exception handling
4991 Gdb now supports limited C++ exception handling. Besides the existing
4992 ability to breakpoint on an exception handler, gdb can breakpoint on
4993 the raising of an exception (before the stack is peeled back to the
4996 catch FOO: If there is a FOO exception handler in the dynamic scope,
4997 set a breakpoint to catch exceptions which may be raised there.
4998 Multiple exceptions (``catch foo bar baz'') may be caught.
5000 info catch: Lists all exceptions which may be caught in the
5001 current stack frame.
5004 * Minor command changes
5006 The command ``call func (arg, arg, ...)'' now acts like the print
5007 command, except it does not print or save a value if the function's result
5008 is void. This is similar to dbx usage.
5010 The ``up'' and ``down'' commands now always print the frame they end up
5011 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5012 frames without printing.
5014 * New directory command
5016 'dir' now adds directories to the FRONT of the source search path.
5017 The path starts off empty. Source files that contain debug information
5018 about the directory in which they were compiled can be found even
5019 with an empty path; Sun CC and GCC include this information. If GDB can't
5020 find your source file in the current directory, type "dir .".
5022 * Configuring GDB for compilation
5024 For normal use, type ``./configure host''. See README or gdb.texinfo
5027 GDB now handles cross debugging. If you are remotely debugging between
5028 two different machines, type ``./configure host -target=targ''.
5029 Host is the machine where GDB will run; targ is the machine
5030 where the program that you are debugging will run.