1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
6 * GDB now supports access to MIPS DSP registers on Linux targets.
8 * GDB now supports debugging microMIPS binaries.
10 * The "info os" command on GNU/Linux can now display information on
11 several new classes of objects managed by the operating system:
12 "info os procgroups" lists process groups
13 "info os files" lists file descriptors
14 "info os sockets" lists internet-domain sockets
15 "info os shm" lists shared-memory regions
16 "info os semaphores" lists semaphores
17 "info os msg" lists message queues
18 "info os modules" lists loaded kernel modules
20 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
21 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
22 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
23 options and inspect the probe arguments using the new $_probe_arg family
24 of convenience variables. You can obtain more information about SystemTap
25 in <http://sourceware.org/systemtap/>.
27 * GDB now supports reversible debugging on ARM, it allows you to
28 debug basic ARM and THUMB instructions, and provides
29 record/replay support.
31 * The option "symbol-reloading" has been deleted as it is no longer used.
35 ** GDB commands implemented in Python can now be put in command class
38 ** The "maint set python print-stack on|off" is now deleted.
40 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
41 apply "flag enum"-style pretty-printing to any enum.
43 ** gdb.lookup_symbol can now work when there is no current frame.
45 ** gdb.Symbol now has a 'line' attribute, holding the line number in
46 the source at which the symbol was defined.
48 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
49 method 'value'. The former indicates whether the symbol needs a
50 frame in order to compute its value, and the latter computes the
53 ** A new method 'referenced_value' on gdb.Value objects which can
54 dereference pointer as well as C++ reference values.
56 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
57 which return the global and static blocks (as gdb.Block objects),
58 of the underlying symbol table, respectively.
60 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
61 object associated with a PC value.
63 * Go language support.
64 GDB now supports debugging programs written in the Go programming
67 * GDBserver now supports stdio connections.
68 E.g. (gdb) target remote | ssh myhost gdbserver - hello
70 * The binary "gdbtui" can no longer be built or installed.
71 Use "gdb -tui" instead.
73 * GDB will now print "flag" enums specially. A flag enum is one where
74 all the enumerator values have no bits in common when pairwise
75 "and"ed. When printing a value whose type is a flag enum, GDB will
76 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
77 (gdb) print (enum E) 3
80 * The filename part of a linespec will now match trailing components
81 of a source file name. For example, "break gcc/expr.c:1000" will
82 now set a breakpoint in build/gcc/expr.c, but not
85 * The "info proc" and "generate-core-file" commands will now also
86 work on remote targets connected to GDBserver on Linux.
88 * The command "info catch" has been removed. It has been disabled
91 * The "catch exception" and "catch assert" commands now accept
92 a condition at the end of the command, much like the "break"
93 command does. For instance:
95 (gdb) catch exception Constraint_Error if Barrier = True
97 Previously, it was possible to add a condition to such catchpoints,
98 but it had to be done as a second step, after the catchpoint had been
99 created, using the "condition" command.
101 * The "info static-tracepoint-marker" command will now also work on
102 native Linux targets with in-process agent.
104 * GDB can now set breakpoints on inlined functions.
106 * The .gdb_index section has been updated to include symbols for
107 inlined functions. GDB will ignore older .gdb_index sections by
108 default, which could cause symbol files to be loaded more slowly
109 until their .gdb_index sections can be recreated. The new option
110 --use-deprecated-index-sections will cause GDB to use any older
111 .gdb_index sections it finds. This will restore performance, but
112 the ability to set breakpoints on inlined functions will be lost
113 in symbol files with older .gdb_index sections.
115 * Ada support for GDB/MI Variable Objects has been added.
117 * GDB can now support 'breakpoint always-inserted mode' in 'record'
122 ** New command -info-os is the MI equivalent of "info os".
126 ** "catch load" and "catch unload" can be used to stop when a shared
127 library is loaded or unloaded, respectively.
129 ** "enable count" can be used to auto-disable a breakpoint after
132 ** "info vtbl" can be used to show the virtual method tables for
133 C++ and Java objects.
135 ** "explore" and its sub commands "explore value" and "explore type"
136 can be used to reccursively explore values and types of
137 expressions. These commands are available only if GDB is
138 configured with '--with-python'.
140 ** "info auto-load" shows status of all kinds of auto-loaded files,
141 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
142 sequences of commands files, "info auto-load python-scripts"
143 shows status of auto-loading Python script files,
144 "info auto-load local-gdbinit" shows status of loading init file
145 (.gdbinit) from current directory and "info auto-load libthread-db" shows
146 status of inferior specific thread debugging shared library loading.
148 ** "info auto-load-scripts", "set auto-load-scripts on|off"
149 and "show auto-load-scripts" commands have been deprecated, use their
150 "info auto-load python-scripts", "set auto-load python-scripts on|off"
151 and "show auto-load python-scripts" counterparts instead.
153 ** "dprintf location,format,args..." creates a dynamic printf, which
154 is basically a breakpoint that does a printf and immediately
155 resumes your program's execution, so it is like a printf that you
156 can insert dynamically at runtime instead of at compiletime.
158 ** "set print symbol"
160 Controls whether GDB attempts to display the symbol, if any,
161 corresponding to addresses it prints. This defaults to "on", but
162 you can set it to "off" to restore GDB's previous behavior.
164 * Deprecated commands
166 ** For the Renesas Super-H architecture, the "regs" command has been
167 deprecated, and "info all-registers" should be used instead.
171 Renesas RL78 rl78-*-elf
172 HP OpenVMS ia64 ia64-hp-openvms*
174 * GDBserver supports evaluation of breakpoint conditions. When
175 support is advertised by GDBserver, GDB may be told to send the
176 breakpoint conditions in bytecode form to GDBserver. GDBserver
177 will only report the breakpoint trigger to GDB when its condition
183 show mips compression
184 Select the compressed ISA encoding used in functions that have no symbol
185 information available. The encoding can be set to either of:
188 and is updated automatically from ELF file flags if available.
190 set breakpoint condition-evaluation
191 show breakpoint condition-evaluation
192 Control whether breakpoint conditions are evaluated by GDB ("host") or by
193 GDBserver ("target"). Default option "auto" chooses the most efficient
195 This option can improve debugger efficiency depending on the speed of the
199 Disable auto-loading globally.
202 Show auto-loading setting of all kinds of auto-loaded files.
204 set auto-load gdb-scripts on|off
205 show auto-load gdb-scripts
206 Control auto-loading of GDB canned sequences of commands files.
208 set auto-load python-scripts on|off
209 show auto-load python-scripts
210 Control auto-loading of Python script files.
212 set auto-load local-gdbinit on|off
213 show auto-load local-gdbinit
214 Control loading of init file (.gdbinit) from current directory.
216 set auto-load libthread-db on|off
217 show auto-load libthread-db
218 Control auto-loading of inferior specific thread debugging shared library.
220 set auto-load scripts-directory <dir1>[:<dir2>...]
221 show auto-load scripts-directory
222 Set a list of directories from which to load auto-loaded scripts.
223 Automatically loaded Python scripts and GDB scripts are located in one
224 of the directories listed by this option.
225 The delimiter (':' above) may differ according to the host platform.
227 set auto-load safe-path <dir1>[:<dir2>...]
228 show auto-load safe-path
229 Set a list of directories from which it is safe to auto-load files.
230 The delimiter (':' above) may differ according to the host platform.
232 set debug auto-load on|off
234 Control display of debugging info for auto-loading the files above.
236 set dprintf-style gdb|call
238 Control the way in which a dynamic printf is performed; "gdb" requests
239 a GDB printf command, while "call" causes dprintf to call a function
242 set dprintf-function <expr>
243 show dprintf-function
244 set dprintf-channel <expr>
246 Set the function and optional first argument to the call when using
247 the "call" style of dynamic printf.
249 * New configure options
252 Configure default value for the 'set auto-load scripts-directory'
253 setting above. It defaults to '$debugdir:$datadir/auto-load',
254 $debugdir representing global debugging info directories (available
255 via 'show debug-file-directory') and $datadir representing GDB's data
256 directory (available via 'show data-directory').
258 --with-auto-load-safe-path
259 Configure default value for the 'set auto-load safe-path' setting
260 above. It defaults to the --with-auto-load-dir setting.
262 --without-auto-load-safe-path
263 Set 'set auto-load safe-path' to '/', effectively disabling this
268 z0/z1 conditional breakpoints extension
270 The z0/z1 breakpoint insertion packets have been extended to carry
271 a list of conditional expressions over to the remote stub depending on the
272 condition evaluation mode. The use of this extension can be controlled
273 via the "set remote conditional-breakpoints-packet" command.
277 Specify the signals which the remote stub may pass to the debugged
278 program without GDB involvement.
280 * New command line options
282 --init-command=FILE, -ix Like --command, -x but execute it
283 before loading inferior.
284 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
285 execute it before loading inferior.
287 *** Changes in GDB 7.4
289 * GDB now handles ambiguous linespecs more consistently; the existing
290 FILE:LINE support has been expanded to other types of linespecs. A
291 breakpoint will now be set on all matching locations in all
292 inferiors, and locations will be added or removed according to
295 * GDB now allows you to skip uninteresting functions and files when
296 stepping with the "skip function" and "skip file" commands.
298 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
299 and "show remote hardware-watchpoint-length-limit". These allows to
300 set or show the maximum length limit (in bytes) of a remote
301 target hardware watchpoint.
303 This allows e.g. to use "unlimited" hardware watchpoints with the
304 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
305 watchpoints are slower than real hardware watchpoints but are
306 significantly faster than gdb software watchpoints.
310 ** The register_pretty_printer function in module gdb.printing now takes
311 an optional `replace' argument. If True, the new printer replaces any
314 ** The "maint set python print-stack on|off" command has been
315 deprecated and will be deleted in GDB 7.5.
316 A new command: "set python print-stack none|full|message" has
317 replaced it. Additionally, the default for "print-stack" is
318 now "message", which just prints the error message without
321 ** A prompt substitution hook (prompt_hook) is now available to the
324 ** A new Python module, gdb.prompt has been added to the GDB Python
325 modules library. This module provides functionality for
326 escape sequences in prompts (used by set/show
327 extended-prompt). These escape sequences are replaced by their
330 ** Python commands and convenience-functions located in
331 'data-directory'/python/gdb/command and
332 'data-directory'/python/gdb/function are now automatically loaded
335 ** Blocks now provide four new attributes. global_block and
336 static_block will return the global and static blocks
337 respectively. is_static and is_global are boolean attributes
338 that indicate if the block is one of those two types.
340 ** Symbols now provide the "type" attribute, the type of the symbol.
342 ** The "gdb.breakpoint" function has been deprecated in favor of
345 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
346 of a function. This class is based on the "finish" command
347 available in the CLI.
349 ** Type objects for struct and union types now allow access to
350 the fields using standard Python dictionary (mapping) methods.
351 For example, "some_type['myfield']" now works, as does
354 ** A new event "gdb.new_objfile" has been added, triggered by loading a
357 ** A new function, "deep_items" has been added to the gdb.types
358 module in the GDB Python modules library. This function returns
359 an iterator over the fields of a struct or union type. Unlike
360 the standard Python "iteritems" method, it will recursively traverse
361 any anonymous fields.
365 ** "*stopped" events can report several new "reason"s, such as
368 ** Breakpoint changes are now notified using new async records, like
369 "=breakpoint-modified".
371 ** New command -ada-task-info.
373 * libthread-db-search-path now supports two special values: $sdir and $pdir.
374 $sdir specifies the default system locations of shared libraries.
375 $pdir specifies the directory where the libpthread used by the application
378 GDB no longer looks in $sdir and $pdir after it has searched the directories
379 mentioned in libthread-db-search-path. If you want to search those
380 directories, they must be specified in libthread-db-search-path.
381 The default value of libthread-db-search-path on GNU/Linux and Solaris
382 systems is now "$sdir:$pdir".
384 $pdir is not supported by gdbserver, it is currently ignored.
385 $sdir is supported by gdbserver.
387 * New configure option --with-iconv-bin.
388 When using the internationalization support like the one in the GNU C
389 library, GDB will invoke the "iconv" program to get a list of supported
390 character sets. If this program lives in a non-standard location, one can
391 use this option to specify where to find it.
393 * When natively debugging programs on PowerPC BookE processors running
394 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
395 watchpoints, which specify a mask in addition to an address to watch.
396 The mask specifies that some bits of an address (the bits which are
397 reset in the mask) should be ignored when matching the address accessed
398 by the inferior against the watchpoint address. See the "PowerPC Embedded"
399 section in the user manual for more details.
401 * The new option --once causes GDBserver to stop listening for connections once
402 the first connection is made. The listening port used by GDBserver will
403 become available after that.
405 * New commands "info macros" and "alias" have been added.
407 * New function parameters suffix @entry specifies value of function parameter
408 at the time the function got called. Entry values are available only since
414 "!" is now an alias of the "shell" command.
415 Note that no space is needed between "!" and SHELL COMMAND.
419 watch EXPRESSION mask MASK_VALUE
420 The watch command now supports the mask argument which allows creation
421 of masked watchpoints, if the current architecture supports this feature.
423 info auto-load-scripts [REGEXP]
424 This command was formerly named "maintenance print section-scripts".
425 It is now generally useful and is no longer a maintenance-only command.
427 info macro [-all] [--] MACRO
428 The info macro command has new options `-all' and `--'. The first for
429 printing all definitions of a macro. The second for explicitly specifying
430 the end of arguments and the beginning of the macro name in case the macro
431 name starts with a hyphen.
433 collect[/s] EXPRESSIONS
434 The tracepoint collect command now takes an optional modifier "/s"
435 that directs it to dereference pointer-to-character types and
436 collect the bytes of memory up to a zero byte. The behavior is
437 similar to what you see when you use the regular print command on a
438 string. An optional integer following the "/s" sets a bound on the
439 number of bytes that will be collected.
442 The trace start command now interprets any supplied arguments as a
443 note to be recorded with the trace run, with an effect similar to
444 setting the variable trace-notes.
447 The trace stop command now interprets any arguments as a note to be
448 mentioned along with the tstatus report that the trace was stopped
449 with a command. The effect is similar to setting the variable
452 * Tracepoints can now be enabled and disabled at any time after a trace
453 experiment has been started using the standard "enable" and "disable"
454 commands. It is now possible to start a trace experiment with no enabled
455 tracepoints; GDB will display a warning, but will allow the experiment to
456 begin, assuming that tracepoints will be enabled as needed while the trace
459 * Fast tracepoints on 32-bit x86-architectures can now be placed at
460 locations with 4-byte instructions, when they were previously
461 limited to locations with instructions of 5 bytes or longer.
467 Set the GDB prompt, and allow escape sequences to be inserted to
468 display miscellaneous information (see 'help set extended-prompt'
469 for the list of sequences). This prompt (and any information
470 accessed through the escape sequences) is updated every time the
473 set print entry-values (both|compact|default|if-needed|no|only|preferred)
474 show print entry-values
475 Set printing of frame argument values at function entry. In some cases
476 GDB can determine the value of function argument which was passed by the
477 function caller, even if the value was modified inside the called function.
479 set debug entry-values
480 show debug entry-values
481 Control display of debugging info for determining frame argument values at
482 function entry and virtual tail call frames.
484 set basenames-may-differ
485 show basenames-may-differ
486 Set whether a source file may have multiple base names.
487 (A "base name" is the name of a file with the directory part removed.
488 Example: The base name of "/home/user/hello.c" is "hello.c".)
489 If set, GDB will canonicalize file names (e.g., expand symlinks)
490 before comparing them. Canonicalization is an expensive operation,
491 but it allows the same file be known by more than one base name.
492 If not set (the default), all source files are assumed to have just
493 one base name, and gdb will do file name comparisons more efficiently.
499 Set a user name and notes for the current and any future trace runs.
500 This is useful for long-running and/or disconnected traces, to
501 inform others (or yourself) as to who is running the trace, supply
502 contact information, or otherwise explain what is going on.
505 show trace-stop-notes
506 Set a note attached to the trace run, that is displayed when the
507 trace has been stopped by a tstop command. This is useful for
508 instance as an explanation, if you are stopping a trace run that was
509 started by someone else.
515 Dynamically enable a tracepoint in a started trace experiment.
519 Dynamically disable a tracepoint in a started trace experiment.
523 Set the user and notes of the trace run.
527 Query the current status of a tracepoint.
531 Query the minimum length of instruction at which a fast tracepoint may
534 * Dcache size (number of lines) and line-size are now runtime-configurable
535 via "set dcache line" and "set dcache line-size" commands.
539 Texas Instruments TMS320C6x tic6x-*-*
543 Renesas RL78 rl78-*-elf
545 *** Changes in GDB 7.3.1
547 * The build failure for NetBSD and OpenBSD targets have now been fixed.
549 *** Changes in GDB 7.3
551 * GDB has a new command: "thread find [REGEXP]".
552 It finds the thread id whose name, target id, or thread extra info
553 matches the given regular expression.
555 * The "catch syscall" command now works on mips*-linux* targets.
557 * The -data-disassemble MI command now supports modes 2 and 3 for
558 dumping the instruction opcodes.
560 * New command line options
562 -data-directory DIR Specify DIR as the "data-directory".
563 This is mostly for testing purposes.
565 * The "maint set python auto-load on|off" command has been renamed to
566 "set auto-load-scripts on|off".
568 * GDB has a new command: "set directories".
569 It is like the "dir" command except that it replaces the
570 source path list instead of augmenting it.
572 * GDB now understands thread names.
574 On GNU/Linux, "info threads" will display the thread name as set by
575 prctl or pthread_setname_np.
577 There is also a new command, "thread name", which can be used to
578 assign a name internally for GDB to display.
581 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
582 has been integrated into GDB.
586 ** The function gdb.Write now accepts an optional keyword 'stream'.
587 This keyword, when provided, will direct the output to either
588 stdout, stderr, or GDB's logging output.
590 ** Parameters can now be be sub-classed in Python, and in particular
591 you may implement the get_set_doc and get_show_doc functions.
592 This improves how Parameter set/show documentation is processed
593 and allows for more dynamic content.
595 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
596 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
597 have an is_valid method.
599 ** Breakpoints can now be sub-classed in Python, and in particular
600 you may implement a 'stop' function that is executed each time
601 the inferior reaches that breakpoint.
603 ** New function gdb.lookup_global_symbol looks up a global symbol.
605 ** GDB values in Python are now callable if the value represents a
606 function. For example, if 'some_value' represents a function that
607 takes two integer parameters and returns a value, you can call
608 that function like so:
610 result = some_value (10,20)
612 ** Module gdb.types has been added.
613 It contains a collection of utilities for working with gdb.Types objects:
614 get_basic_type, has_field, make_enum_dict.
616 ** Module gdb.printing has been added.
617 It contains utilities for writing and registering pretty-printers.
618 New classes: PrettyPrinter, SubPrettyPrinter,
619 RegexpCollectionPrettyPrinter.
620 New function: register_pretty_printer.
622 ** New commands "info pretty-printers", "enable pretty-printer" and
623 "disable pretty-printer" have been added.
625 ** gdb.parameter("directories") is now available.
627 ** New function gdb.newest_frame returns the newest frame in the
630 ** The gdb.InferiorThread class has a new "name" attribute. This
631 holds the thread's name.
633 ** Python Support for Inferior events.
634 Python scripts can add observers to be notified of events
635 occurring in the process being debugged.
636 The following events are currently supported:
637 - gdb.events.cont Continue event.
638 - gdb.events.exited Inferior exited event.
639 - gdb.events.stop Signal received, and Breakpoint hit events.
643 ** GDB now puts template parameters in scope when debugging in an
644 instantiation. For example, if you have:
646 template<int X> int func (void) { return X; }
648 then if you step into func<5>, "print X" will show "5". This
649 feature requires proper debuginfo support from the compiler; it
650 was added to GCC 4.5.
652 ** The motion commands "next", "finish", "until", and "advance" now
653 work better when exceptions are thrown. In particular, GDB will
654 no longer lose control of the inferior; instead, the GDB will
655 stop the inferior at the point at which the exception is caught.
656 This functionality requires a change in the exception handling
657 code that was introduced in GCC 4.5.
659 * GDB now follows GCC's rules on accessing volatile objects when
660 reading or writing target state during expression evaluation.
661 One notable difference to prior behavior is that "print x = 0"
662 no longer generates a read of x; the value of the assignment is
663 now always taken directly from the value being assigned.
665 * GDB now has some support for using labels in the program's source in
666 linespecs. For instance, you can use "advance label" to continue
667 execution to a label.
669 * GDB now has support for reading and writing a new .gdb_index
670 section. This section holds a fast index of DWARF debugging
671 information and can be used to greatly speed up GDB startup and
672 operation. See the documentation for `save gdb-index' for details.
674 * The "watch" command now accepts an optional "-location" argument.
675 When used, this causes GDB to watch the memory referred to by the
676 expression. Such a watchpoint is never deleted due to it going out
679 * GDB now supports thread debugging of core dumps on GNU/Linux.
681 GDB now activates thread debugging using the libthread_db library
682 when debugging GNU/Linux core dumps, similarly to when debugging
683 live processes. As a result, when debugging a core dump file, GDB
684 is now able to display pthread_t ids of threads. For example, "info
685 threads" shows the same output as when debugging the process when it
686 was live. In earlier releases, you'd see something like this:
689 * 1 LWP 6780 main () at main.c:10
691 While now you see this:
694 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
696 It is also now possible to inspect TLS variables when debugging core
699 When debugging a core dump generated on a machine other than the one
700 used to run GDB, you may need to point GDB at the correct
701 libthread_db library with the "set libthread-db-search-path"
702 command. See the user manual for more details on this command.
704 * When natively debugging programs on PowerPC BookE processors running
705 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
706 which stop execution of the inferior whenever it executes an instruction
707 at any address within the specified range. See the "PowerPC Embedded"
708 section in the user manual for more details.
710 * New features in the GDB remote stub, GDBserver
712 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
713 and i686 LynxOS (version 5.x).
715 ** GDBserver is now supported on Blackfin Linux.
717 * New native configurations
719 ia64 HP-UX ia64-*-hpux*
723 Analog Devices, Inc. Blackfin Processor bfin-*
725 * Ada task switching is now supported on sparc-elf targets when
726 debugging a program using the Ravenscar Profile. For more information,
727 see the "Tasking Support when using the Ravenscar Profile" section
728 in the GDB user manual.
730 * Guile support was removed.
732 * New features in the GNU simulator
734 ** The --map-info flag lists all known core mappings.
736 ** CFI flashes may be simulated via the "cfi" device.
738 *** Changes in GDB 7.2
740 * Shared library support for remote targets by default
742 When GDB is configured for a generic, non-OS specific target, like
743 for example, --target=arm-eabi or one of the many *-*-elf targets,
744 GDB now queries remote stubs for loaded shared libraries using the
745 `qXfer:libraries:read' packet. Previously, shared library support
746 was always disabled for such configurations.
750 ** Argument Dependent Lookup (ADL)
752 In C++ ADL lookup directs function search to the namespaces of its
753 arguments even if the namespace has not been imported.
763 Here the compiler will search for `foo' in the namespace of 'b'
764 and find A::foo. GDB now supports this. This construct is commonly
765 used in the Standard Template Library for operators.
767 ** Improved User Defined Operator Support
769 In addition to member operators, GDB now supports lookup of operators
770 defined in a namespace and imported with a `using' directive, operators
771 defined in the global scope, operators imported implicitly from an
772 anonymous namespace, and the ADL operators mentioned in the previous
774 GDB now also supports proper overload resolution for all the previously
775 mentioned flavors of operators.
777 ** static const class members
779 Printing of static const class members that are initialized in the
780 class definition has been fixed.
782 * Windows Thread Information Block access.
784 On Windows targets, GDB now supports displaying the Windows Thread
785 Information Block (TIB) structure. This structure is visible either
786 by using the new command `info w32 thread-information-block' or, by
787 dereferencing the new convenience variable named `$_tlb', a
788 thread-specific pointer to the TIB. This feature is also supported
789 when remote debugging using GDBserver.
793 Static tracepoints are calls in the user program into a tracing
794 library. One such library is a port of the LTTng kernel tracer to
795 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
796 When debugging with GDBserver, GDB now supports combining the GDB
797 tracepoint machinery with such libraries. For example: the user can
798 use GDB to probe a static tracepoint marker (a call from the user
799 program into the tracing library) with the new "strace" command (see
800 "New commands" below). This creates a "static tracepoint" in the
801 breakpoint list, that can be manipulated with the same feature set
802 as fast and regular tracepoints. E.g., collect registers, local and
803 global variables, collect trace state variables, and define
804 tracepoint conditions. In addition, the user can collect extra
805 static tracepoint marker specific data, by collecting the new
806 $_sdata internal variable. When analyzing the trace buffer, you can
807 inspect $_sdata like any other variable available to GDB. For more
808 information, see the "Tracepoints" chapter in GDB user manual. New
809 remote packets have been defined to support static tracepoints, see
810 the "New remote packets" section below.
812 * Better reconstruction of tracepoints after disconnected tracing
814 GDB will attempt to download the original source form of tracepoint
815 definitions when starting a trace run, and then will upload these
816 upon reconnection to the target, resulting in a more accurate
817 reconstruction of the tracepoints that are in use on the target.
821 You can now exercise direct control over the ways that GDB can
822 affect your program. For instance, you can disallow the setting of
823 breakpoints, so that the program can run continuously (assuming
824 non-stop mode). In addition, the "observer" variable is available
825 to switch all of the different controls; in observer mode, GDB
826 cannot affect the target's behavior at all, which is useful for
827 tasks like diagnosing live systems in the field.
829 * The new convenience variable $_thread holds the number of the
836 Return the address of the Windows Thread Information Block of a given thread.
840 In response to several of the tracepoint packets, the target may now
841 also respond with a number of intermediate `qRelocInsn' request
842 packets before the final result packet, to have GDB handle
843 relocating an instruction to execute at a different address. This
844 is particularly useful for stubs that support fast tracepoints. GDB
845 reports support for this feature in the qSupported packet.
849 List static tracepoint markers in the target program.
853 List static tracepoint markers at a given address in the target
856 qXfer:statictrace:read
858 Read the static trace data collected (by a `collect $_sdata'
859 tracepoint action). The remote stub reports support for this packet
860 to gdb's qSupported query.
864 Send the current settings of GDB's permission flags.
868 Send part of the source (textual) form of a tracepoint definition,
869 which includes location, conditional, and action list.
871 * The source command now accepts a -s option to force searching for the
872 script in the source search path even if the script name specifies
875 * New features in the GDB remote stub, GDBserver
877 - GDBserver now support tracepoints (including fast tracepoints, and
878 static tracepoints). The feature is currently supported by the
879 i386-linux and amd64-linux builds. See the "Tracepoints support
880 in gdbserver" section in the manual for more information.
882 GDBserver JIT compiles the tracepoint's conditional agent
883 expression bytecode into native code whenever possible for low
884 overhead dynamic tracepoints conditionals. For such tracepoints,
885 an expression that examines program state is evaluated when the
886 tracepoint is reached, in order to determine whether to capture
887 trace data. If the condition is simple and false, processing the
888 tracepoint finishes very quickly and no data is gathered.
890 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
891 for static tracepoints support.
893 - GDBserver now supports x86_64 Windows 64-bit debugging.
895 * GDB now sends xmlRegisters= in qSupported packet to indicate that
896 it understands register description.
898 * The --batch flag now disables pagination and queries.
900 * X86 general purpose registers
902 GDB now supports reading/writing byte, word and double-word x86
903 general purpose registers directly. This means you can use, say,
904 $ah or $ax to refer, respectively, to the byte register AH and
905 16-bit word register AX that are actually portions of the 32-bit
906 register EAX or 64-bit register RAX.
908 * The `commands' command now accepts a range of breakpoints to modify.
909 A plain `commands' following a command that creates multiple
910 breakpoints affects all the breakpoints set by that command. This
911 applies to breakpoints set by `rbreak', and also applies when a
912 single `break' command creates multiple breakpoints (e.g.,
913 breakpoints on overloaded c++ functions).
915 * The `rbreak' command now accepts a filename specification as part of
916 its argument, limiting the functions selected by the regex to those
917 in the specified file.
919 * Support for remote debugging Windows and SymbianOS shared libraries
920 from Unix hosts has been improved. Non Windows GDB builds now can
921 understand target reported file names that follow MS-DOS based file
922 system semantics, such as file names that include drive letters and
923 use the backslash character as directory separator. This makes it
924 possible to transparently use the "set sysroot" and "set
925 solib-search-path" on Unix hosts to point as host copies of the
926 target's shared libraries. See the new command "set
927 target-file-system-kind" described below, and the "Commands to
928 specify files" section in the user manual for more information.
932 eval template, expressions...
933 Convert the values of one or more expressions under the control
934 of the string template to a command line, and call it.
936 set target-file-system-kind unix|dos-based|auto
937 show target-file-system-kind
938 Set or show the assumed file system kind for target reported file
941 save breakpoints <filename>
942 Save all current breakpoint definitions to a file suitable for use
943 in a later debugging session. To read the saved breakpoint
944 definitions, use the `source' command.
946 `save tracepoints' is a new alias for `save-tracepoints'. The latter
949 info static-tracepoint-markers
950 Display information about static tracepoint markers in the target.
952 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
953 Define a static tracepoint by probing a marker at the given
954 function, line, address, or marker ID.
958 Enable and disable observer mode.
960 set may-write-registers on|off
961 set may-write-memory on|off
962 set may-insert-breakpoints on|off
963 set may-insert-tracepoints on|off
964 set may-insert-fast-tracepoints on|off
965 set may-interrupt on|off
966 Set individual permissions for GDB effects on the target. Note that
967 some of these settings can have undesirable or surprising
968 consequences, particularly when changed in the middle of a session.
969 For instance, disabling the writing of memory can prevent
970 breakpoints from being inserted, cause single-stepping to fail, or
971 even crash your program, if you disable after breakpoints have been
972 inserted. However, GDB should not crash.
974 set record memory-query on|off
975 show record memory-query
976 Control whether to stop the inferior if memory changes caused
977 by an instruction cannot be recorded.
982 The disassemble command now supports "start,+length" form of two arguments.
986 ** GDB now provides a new directory location, called the python directory,
987 where Python scripts written for GDB can be installed. The location
988 of that directory is <data-directory>/python, where <data-directory>
989 is the GDB data directory. For more details, see section `Scripting
990 GDB using Python' in the manual.
992 ** The GDB Python API now has access to breakpoints, symbols, symbol
993 tables, program spaces, inferiors, threads and frame's code blocks.
994 Additionally, GDB Parameters can now be created from the API, and
995 manipulated via set/show in the CLI.
997 ** New functions gdb.target_charset, gdb.target_wide_charset,
998 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1000 ** New exception gdb.GdbError.
1002 ** Pretty-printers are now also looked up in the current program space.
1004 ** Pretty-printers can now be individually enabled and disabled.
1006 ** GDB now looks for names of Python scripts to auto-load in a
1007 special section named `.debug_gdb_scripts', in addition to looking
1008 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1010 * Tracepoint actions were unified with breakpoint commands. In particular,
1011 there are no longer differences in "info break" output for breakpoints and
1012 tracepoints and the "commands" command can be used for both tracepoints and
1013 regular breakpoints.
1017 ARM Symbian arm*-*-symbianelf*
1019 * D language support.
1020 GDB now supports debugging programs written in the D programming
1023 * GDB now supports the extended ptrace interface for PowerPC which is
1024 available since Linux kernel version 2.6.34. This automatically enables
1025 any hardware breakpoints and additional hardware watchpoints available in
1026 the processor. The old ptrace interface exposes just one hardware
1027 watchpoint and no hardware breakpoints.
1029 * GDB is now able to use the Data Value Compare (DVC) register available on
1030 embedded PowerPC processors to implement in hardware simple watchpoint
1031 conditions of the form:
1033 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1035 This works in native GDB running on Linux kernels with the extended ptrace
1036 interface mentioned above.
1038 *** Changes in GDB 7.1
1042 ** Namespace Support
1044 GDB now supports importing of namespaces in C++. This enables the
1045 user to inspect variables from imported namespaces. Support for
1046 namepace aliasing has also been added. So, if a namespace is
1047 aliased in the current scope (e.g. namepace C=A; ) the user can
1048 print variables using the alias (e.g. (gdb) print C::x).
1052 All known bugs relating to the printing of virtual base class were
1053 fixed. It is now possible to call overloaded static methods using a
1058 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1059 and reinterpret_cast<> are now handled by the C++ expression parser.
1063 Xilinx MicroBlaze microblaze-*-*
1068 Xilinx MicroBlaze microblaze
1071 * Multi-program debugging.
1073 GDB now has support for multi-program (a.k.a. multi-executable or
1074 multi-exec) debugging. This allows for debugging multiple inferiors
1075 simultaneously each running a different program under the same GDB
1076 session. See "Debugging Multiple Inferiors and Programs" in the
1077 manual for more information. This implied some user visible changes
1078 in the multi-inferior support. For example, "info inferiors" now
1079 lists inferiors that are not running yet or that have exited
1080 already. See also "New commands" and "New options" below.
1082 * New tracing features
1084 GDB's tracepoint facility now includes several new features:
1086 ** Trace state variables
1088 GDB tracepoints now include support for trace state variables, which
1089 are variables managed by the target agent during a tracing
1090 experiment. They are useful for tracepoints that trigger each
1091 other, so for instance one tracepoint can count hits in a variable,
1092 and then a second tracepoint has a condition that is true when the
1093 count reaches a particular value. Trace state variables share the
1094 $-syntax of GDB convenience variables, and can appear in both
1095 tracepoint actions and condition expressions. Use the "tvariable"
1096 command to create, and "info tvariables" to view; see "Trace State
1097 Variables" in the manual for more detail.
1101 GDB now includes an option for defining fast tracepoints, which
1102 targets may implement more efficiently, such as by installing a jump
1103 into the target agent rather than a trap instruction. The resulting
1104 speedup can be by two orders of magnitude or more, although the
1105 tradeoff is that some program locations on some target architectures
1106 might not allow fast tracepoint installation, for instance if the
1107 instruction to be replaced is shorter than the jump. To request a
1108 fast tracepoint, use the "ftrace" command, with syntax identical to
1109 the regular trace command.
1111 ** Disconnected tracing
1113 It is now possible to detach GDB from the target while it is running
1114 a trace experiment, then reconnect later to see how the experiment
1115 is going. In addition, a new variable disconnected-tracing lets you
1116 tell the target agent whether to continue running a trace if the
1117 connection is lost unexpectedly.
1121 GDB now has the ability to save the trace buffer into a file, and
1122 then use that file as a target, similarly to you can do with
1123 corefiles. You can select trace frames, print data that was
1124 collected in them, and use tstatus to display the state of the
1125 tracing run at the moment that it was saved. To create a trace
1126 file, use "tsave <filename>", and to use it, do "target tfile
1129 ** Circular trace buffer
1131 You can ask the target agent to handle the trace buffer as a
1132 circular buffer, discarding the oldest trace frames to make room for
1133 newer ones, by setting circular-trace-buffer to on. This feature may
1134 not be available for all target agents.
1139 The disassemble command, when invoked with two arguments, now requires
1140 the arguments to be comma-separated.
1143 The info variables command now displays variable definitions. Files
1144 which only declare a variable are not shown.
1147 The source command is now capable of sourcing Python scripts.
1148 This feature is dependent on the debugger being build with Python
1151 Related to this enhancement is also the introduction of a new command
1152 "set script-extension" (see below).
1154 * New commands (for set/show, see "New options" below)
1156 record save [<FILENAME>]
1157 Save a file (in core file format) containing the process record
1158 execution log for replay debugging at a later time.
1160 record restore <FILENAME>
1161 Restore the process record execution log that was saved at an
1162 earlier time, for replay debugging.
1164 add-inferior [-copies <N>] [-exec <FILENAME>]
1167 clone-inferior [-copies <N>] [ID]
1168 Make a new inferior ready to execute the same program another
1169 inferior has loaded.
1174 maint info program-spaces
1175 List the program spaces loaded into GDB.
1177 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1178 show remote interrupt-sequence
1179 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1180 as the sequence to the remote target in order to interrupt the execution.
1181 Ctrl-C is a default. Some system prefers BREAK which is high level of
1182 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1183 Magic SysRq g. It is BREAK signal and character 'g'.
1185 set remote interrupt-on-connect [on | off]
1186 show remote interrupt-on-connect
1187 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1188 remote target when gdb connects to it. This is needed when you debug
1191 set remotebreak [on | off]
1193 Deprecated. Use "set/show remote interrupt-sequence" instead.
1195 tvariable $NAME [ = EXP ]
1196 Create or modify a trace state variable.
1199 List trace state variables and their values.
1201 delete tvariable $NAME ...
1202 Delete one or more trace state variables.
1205 Evaluate the given expressions without collecting anything into the
1206 trace buffer. (Valid in tracepoint actions only.)
1208 ftrace FN / FILE:LINE / *ADDR
1209 Define a fast tracepoint at the given function, line, or address.
1211 * New expression syntax
1213 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1214 GDB now parses 0b101010 identically with 42.
1218 set follow-exec-mode new|same
1219 show follow-exec-mode
1220 Control whether GDB reuses the same inferior across an exec call or
1221 creates a new one. This is useful to be able to restart the old
1222 executable after the inferior having done an exec call.
1224 set default-collect EXPR, ...
1225 show default-collect
1226 Define a list of expressions to be collected at each tracepoint.
1227 This is a useful way to ensure essential items are not overlooked,
1228 such as registers or a critical global variable.
1230 set disconnected-tracing
1231 show disconnected-tracing
1232 If set to 1, the target is instructed to continue tracing if it
1233 loses its connection to GDB. If 0, the target is to stop tracing
1236 set circular-trace-buffer
1237 show circular-trace-buffer
1238 If set to on, the target is instructed to use a circular trace buffer
1239 and discard the oldest trace frames instead of stopping the trace due
1240 to a full trace buffer. If set to off, the trace stops when the buffer
1241 fills up. Some targets may not support this.
1243 set script-extension off|soft|strict
1244 show script-extension
1245 If set to "off", the debugger does not perform any script language
1246 recognition, and all sourced files are assumed to be GDB scripts.
1247 If set to "soft" (the default), files are sourced according to
1248 filename extension, falling back to GDB scripts if the first
1250 If set to "strict", files are sourced according to filename extension.
1252 set ada trust-PAD-over-XVS on|off
1253 show ada trust-PAD-over-XVS
1254 If off, activate a workaround against a bug in the debugging information
1255 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1256 the GCC sources for more information about the GNAT encoding and
1257 PAD types in particular). It is always safe to set this option to
1258 off, but this introduces a slight performance penalty. The default
1261 * Python API Improvements
1263 ** GDB provides the new class gdb.LazyString. This is useful in
1264 some pretty-printing cases. The new method gdb.Value.lazy_string
1265 provides a simple way to create objects of this type.
1267 ** The fields returned by gdb.Type.fields now have an
1268 `is_base_class' attribute.
1270 ** The new method gdb.Type.range returns the range of an array type.
1272 ** The new method gdb.parse_and_eval can be used to parse and
1273 evaluate an expression.
1275 * New remote packets
1278 Define a trace state variable.
1281 Get the current value of a trace state variable.
1284 Set desired tracing behavior upon disconnection.
1287 Set the trace buffer to be linear or circular.
1290 Get data about the tracepoints currently in use.
1294 Process record now works correctly with hardware watchpoints.
1296 Multiple bug fixes have been made to the mips-irix port, making it
1297 much more reliable. In particular:
1298 - Debugging threaded applications is now possible again. Previously,
1299 GDB would hang while starting the program, or while waiting for
1300 the program to stop at a breakpoint.
1301 - Attaching to a running process no longer hangs.
1302 - An error occurring while loading a core file has been fixed.
1303 - Changing the value of the PC register now works again. This fixes
1304 problems observed when using the "jump" command, or when calling
1305 a function from GDB, or even when assigning a new value to $pc.
1306 - With the "finish" and "return" commands, the return value for functions
1307 returning a small array is now correctly printed.
1308 - It is now possible to break on shared library code which gets executed
1309 during a shared library init phase (code executed while executing
1310 their .init section). Previously, the breakpoint would have no effect.
1311 - GDB is now able to backtrace through the signal handler for
1312 non-threaded programs.
1314 PIE (Position Independent Executable) programs debugging is now supported.
1315 This includes debugging execution of PIC (Position Independent Code) shared
1316 libraries although for that, it should be possible to run such libraries as an
1319 *** Changes in GDB 7.0
1321 * GDB now has an interface for JIT compilation. Applications that
1322 dynamically generate code can create symbol files in memory and register
1323 them with GDB. For users, the feature should work transparently, and
1324 for JIT developers, the interface is documented in the GDB manual in the
1325 "JIT Compilation Interface" chapter.
1327 * Tracepoints may now be conditional. The syntax is as for
1328 breakpoints; either an "if" clause appended to the "trace" command,
1329 or the "condition" command is available. GDB sends the condition to
1330 the target for evaluation using the same bytecode format as is used
1331 for tracepoint actions.
1333 * The disassemble command now supports: an optional /r modifier, print the
1334 raw instructions in hex as well as in symbolic form, and an optional /m
1335 modifier to print mixed source+assembly.
1337 * Process record and replay
1339 In a architecture environment that supports ``process record and
1340 replay'', ``process record and replay'' target can record a log of
1341 the process execution, and replay it with both forward and reverse
1344 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1345 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1346 set execution-direction {forward|reverse}, for targets that support
1349 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1350 feature is available with a native GDB running on kernel version
1353 * GDB now has support for multi-byte and wide character sets on the
1354 target. Strings whose character type is wchar_t, char16_t, or
1355 char32_t are now correctly printed. GDB supports wide- and unicode-
1356 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1357 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1358 `printf'. This feature requires iconv to work properly; if your
1359 system does not have a working iconv, GDB can use GNU libiconv. See
1360 the installation instructions for more information.
1362 * GDB now supports automatic retrieval of shared library files from
1363 remote targets. To use this feature, specify a system root that begins
1364 with the `remote:' prefix, either via the `set sysroot' command or via
1365 the `--with-sysroot' configure-time option.
1367 * "info sharedlibrary" now takes an optional regex of libraries to show,
1368 and it now reports if a shared library has no debugging information.
1370 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1371 now complete on file names.
1373 * When completing in expressions, gdb will attempt to limit
1374 completions to allowable structure or union fields, where appropriate.
1375 For instance, consider:
1377 # struct example { int f1; double f2; };
1378 # struct example variable;
1381 If the user types TAB at the end of this command line, the available
1382 completions will be "f1" and "f2".
1384 * Inlined functions are now supported. They show up in backtraces, and
1385 the "step", "next", and "finish" commands handle them automatically.
1387 * GDB now supports the token-splicing (##) and stringification (#)
1388 operators when expanding macros. It also supports variable-arity
1391 * GDB now supports inspecting extra signal information, exported by
1392 the new $_siginfo convenience variable. The feature is currently
1393 implemented on linux ARM, i386 and amd64.
1395 * GDB can now display the VFP floating point registers and NEON vector
1396 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1397 can provide these registers (requires Linux 2.6.30 or later). Remote
1398 and simulator targets may also provide them.
1400 * New remote packets
1403 Search memory for a sequence of bytes.
1406 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1407 operation over reliable transport links. Use of this packet is
1408 controlled by the `set remote noack-packet' command.
1411 Kill the process with the specified process ID. Use this in preference
1412 to `k' when multiprocess protocol extensions are supported.
1415 Obtains additional operating system information
1419 Read or write additional signal information.
1421 * Removed remote protocol undocumented extension
1423 An undocumented extension to the remote protocol's `S' stop reply
1424 packet that permited the stub to pass a process id was removed.
1425 Remote servers should use the `T' stop reply packet instead.
1427 * GDB now supports multiple function calling conventions according to the
1428 DWARF-2 DW_AT_calling_convention function attribute.
1430 * The SH target utilizes the aforementioned change to distinguish between gcc
1431 and Renesas calling convention. It also adds the new CLI commands
1432 `set/show sh calling-convention'.
1434 * GDB can now read compressed debug sections, as produced by GNU gold
1435 with the --compress-debug-sections=zlib flag.
1437 * 64-bit core files are now supported on AIX.
1439 * Thread switching is now supported on Tru64.
1441 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1442 which will be allocated using malloc later in program execution.
1444 * The qXfer:libraries:read remote procotol packet now allows passing a
1445 list of section offsets.
1447 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1448 conditions handling signals delivered during attach or thread creation
1449 have also been fixed.
1451 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1452 From the user's standpoint, all unqualified instances of True and False
1453 are treated as the standard definitions, regardless of context.
1455 * GDB now parses C++ symbol and type names more flexibly. For
1458 template<typename T> class C { };
1461 GDB will now correctly handle all of:
1463 ptype C<char const *>
1464 ptype C<char const*>
1465 ptype C<const char *>
1466 ptype C<const char*>
1468 * New features in the GDB remote stub, gdbserver
1470 - The "--wrapper" command-line argument tells gdbserver to use a
1471 wrapper program to launch programs for debugging.
1473 - On PowerPC and S/390 targets, it is now possible to use a single
1474 gdbserver executable to debug both 32-bit and 64-bit programs.
1475 (This requires gdbserver itself to be built as a 64-bit executable.)
1477 - gdbserver uses the new noack protocol mode for TCP connections to
1478 reduce communications latency, if also supported and enabled in GDB.
1480 - Support for the sparc64-linux-gnu target is now included in
1483 - The amd64-linux build of gdbserver now supports debugging both
1484 32-bit and 64-bit programs.
1486 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1487 now support hardware watchpoints, and will use them automatically
1492 GDB now has support for scripting using Python. Whether this is
1493 available is determined at configure time.
1495 New GDB commands can now be written in Python.
1497 * Ada tasking support
1499 Ada tasks can now be inspected in GDB. The following commands have
1503 Print the list of Ada tasks.
1505 Print detailed information about task number N.
1507 Print the task number of the current task.
1509 Switch the context of debugging to task number N.
1511 * Support for user-defined prefixed commands. The "define" command can
1512 add new commands to existing prefixes, e.g. "target".
1514 * Multi-inferior, multi-process debugging.
1516 GDB now has generalized support for multi-inferior debugging. See
1517 "Debugging Multiple Inferiors" in the manual for more information.
1518 Although availability still depends on target support, the command
1519 set is more uniform now. The GNU/Linux specific multi-forks support
1520 has been migrated to this new framework. This implied some user
1521 visible changes; see "New commands" and also "Removed commands"
1524 * Target descriptions can now describe the target OS ABI. See the
1525 "Target Description Format" section in the user manual for more
1528 * Target descriptions can now describe "compatible" architectures
1529 to indicate that the target can execute applications for a different
1530 architecture in addition to those for the main target architecture.
1531 See the "Target Description Format" section in the user manual for
1534 * Multi-architecture debugging.
1536 GDB now includes general supports for debugging applications on
1537 hybrid systems that use more than one single processor architecture
1538 at the same time. Each such hybrid architecture still requires
1539 specific support to be added. The only hybrid architecture supported
1540 in this version of GDB is the Cell Broadband Engine.
1542 * GDB now supports integrated debugging of Cell/B.E. applications that
1543 use both the PPU and SPU architectures. To enable support for hybrid
1544 Cell/B.E. debugging, you need to configure GDB to support both the
1545 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1546 --enable-targets configure option.
1548 * Non-stop mode debugging.
1550 For some targets, GDB now supports an optional mode of operation in
1551 which you can examine stopped threads while other threads continue
1552 to execute freely. This is referred to as non-stop mode, with the
1553 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1554 section in the user manual for more information.
1556 To be able to support remote non-stop debugging, a remote stub needs
1557 to implement the non-stop mode remote protocol extensions, as
1558 described in the "Remote Non-Stop" section of the user manual. The
1559 GDB remote stub, gdbserver, has been adjusted to support these
1560 extensions on linux targets.
1562 * New commands (for set/show, see "New options" below)
1564 catch syscall [NAME(S) | NUMBER(S)]
1565 Catch system calls. Arguments, which should be names of system
1566 calls or their numbers, mean catch only those syscalls. Without
1567 arguments, every syscall will be caught. When the inferior issues
1568 any of the specified syscalls, GDB will stop and announce the system
1569 call, both when it is called and when its call returns. This
1570 feature is currently available with a native GDB running on the
1571 Linux Kernel, under the following architectures: x86, x86_64,
1572 PowerPC and PowerPC64.
1574 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1576 Search memory for a sequence of bytes.
1578 maint set python print-stack
1579 maint show python print-stack
1580 Show a stack trace when an error is encountered in a Python script.
1583 Invoke CODE by passing it to the Python interpreter.
1588 These allow macros to be defined, undefined, and listed
1592 Show operating system information about processes.
1595 List the inferiors currently under GDB's control.
1598 Switch focus to inferior number NUM.
1601 Detach from inferior number NUM.
1604 Kill inferior number NUM.
1608 set spu stop-on-load
1609 show spu stop-on-load
1610 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1612 set spu auto-flush-cache
1613 show spu auto-flush-cache
1614 Control whether to automatically flush the software-managed cache
1615 during Cell/B.E. debugging.
1617 set sh calling-convention
1618 show sh calling-convention
1619 Control the calling convention used when calling SH target functions.
1622 show debug timestamp
1623 Control display of timestamps with GDB debugging output.
1625 set disassemble-next-line
1626 show disassemble-next-line
1627 Control display of disassembled source lines or instructions when
1630 set remote noack-packet
1631 show remote noack-packet
1632 Set/show the use of remote protocol QStartNoAckMode packet. See above
1633 under "New remote packets."
1635 set remote query-attached-packet
1636 show remote query-attached-packet
1637 Control use of remote protocol `qAttached' (query-attached) packet.
1639 set remote read-siginfo-object
1640 show remote read-siginfo-object
1641 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1644 set remote write-siginfo-object
1645 show remote write-siginfo-object
1646 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1649 set remote reverse-continue
1650 show remote reverse-continue
1651 Control use of remote protocol 'bc' (reverse-continue) packet.
1653 set remote reverse-step
1654 show remote reverse-step
1655 Control use of remote protocol 'bs' (reverse-step) packet.
1657 set displaced-stepping
1658 show displaced-stepping
1659 Control displaced stepping mode. Displaced stepping is a way to
1660 single-step over breakpoints without removing them from the debuggee.
1661 Also known as "out-of-line single-stepping".
1664 show debug displaced
1665 Control display of debugging info for displaced stepping.
1667 maint set internal-error
1668 maint show internal-error
1669 Control what GDB does when an internal error is detected.
1671 maint set internal-warning
1672 maint show internal-warning
1673 Control what GDB does when an internal warning is detected.
1678 Use a wrapper program to launch programs for debugging.
1680 set multiple-symbols (all|ask|cancel)
1681 show multiple-symbols
1682 The value of this variable can be changed to adjust the debugger behavior
1683 when an expression or a breakpoint location contains an ambiguous symbol
1684 name (an overloaded function name, for instance).
1686 set breakpoint always-inserted
1687 show breakpoint always-inserted
1688 Keep breakpoints always inserted in the target, as opposed to inserting
1689 them when resuming the target, and removing them when the target stops.
1690 This option can improve debugger performance on slow remote targets.
1692 set arm fallback-mode (arm|thumb|auto)
1693 show arm fallback-mode
1694 set arm force-mode (arm|thumb|auto)
1696 These commands control how ARM GDB determines whether instructions
1697 are ARM or Thumb. The default for both settings is auto, which uses
1698 the current CPSR value for instructions without symbols; previous
1699 versions of GDB behaved as if "set arm fallback-mode arm".
1701 set disable-randomization
1702 show disable-randomization
1703 Standalone programs run with the virtual address space randomization enabled
1704 by default on some platforms. This option keeps the addresses stable across
1705 multiple debugging sessions.
1709 Control whether other threads are stopped or not when some thread hits
1714 Requests that asynchronous execution is enabled in the target, if available.
1715 In this case, it's possible to resume target in the background, and interact
1716 with GDB while the target is running. "show target-async" displays the
1717 current state of asynchronous execution of the target.
1719 set target-wide-charset
1720 show target-wide-charset
1721 The target-wide-charset is the name of the character set that GDB
1722 uses when printing characters whose type is wchar_t.
1724 set tcp auto-retry (on|off)
1726 set tcp connect-timeout
1727 show tcp connect-timeout
1728 These commands allow GDB to retry failed TCP connections to a remote stub
1729 with a specified timeout period; this is useful if the stub is launched
1730 in parallel with GDB but may not be ready to accept connections immediately.
1732 set libthread-db-search-path
1733 show libthread-db-search-path
1734 Control list of directories which GDB will search for appropriate
1737 set schedule-multiple (on|off)
1738 show schedule-multiple
1739 Allow GDB to resume all threads of all processes or only threads of
1740 the current process.
1744 Use more aggressive caching for accesses to the stack. This improves
1745 performance of remote debugging (particularly backtraces) without
1746 affecting correctness.
1748 set interactive-mode (on|off|auto)
1749 show interactive-mode
1750 Control whether GDB runs in interactive mode (on) or not (off).
1751 When in interactive mode, GDB waits for the user to answer all
1752 queries. Otherwise, GDB does not wait and assumes the default
1753 answer. When set to auto (the default), GDB determines which
1754 mode to use based on the stdin settings.
1759 For program forks, this is replaced by the new more generic `info
1760 inferiors' command. To list checkpoints, you can still use the
1761 `info checkpoints' command, which was an alias for the `info forks'
1765 Replaced by the new `inferior' command. To switch between
1766 checkpoints, you can still use the `restart' command, which was an
1767 alias for the `fork' command.
1770 This is removed, since some targets don't have a notion of
1771 processes. To switch between processes, you can still use the
1772 `inferior' command using GDB's own inferior number.
1775 For program forks, this is replaced by the new more generic `kill
1776 inferior' command. To delete a checkpoint, you can still use the
1777 `delete checkpoint' command, which was an alias for the `delete
1781 For program forks, this is replaced by the new more generic `detach
1782 inferior' command. To detach a checkpoint, you can still use the
1783 `detach checkpoint' command, which was an alias for the `detach
1786 * New native configurations
1788 x86/x86_64 Darwin i[34567]86-*-darwin*
1790 x86_64 MinGW x86_64-*-mingw*
1794 Lattice Mico32 lm32-*
1795 x86 DICOS i[34567]86-*-dicos*
1796 x86_64 DICOS x86_64-*-dicos*
1799 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1800 (mingw32ce) debugging.
1806 These commands were actually not implemented on any target.
1808 *** Changes in GDB 6.8
1810 * New native configurations
1812 NetBSD/hppa hppa*-*netbsd*
1813 Xtensa GNU/Linux xtensa*-*-linux*
1817 NetBSD/hppa hppa*-*-netbsd*
1818 Xtensa GNU/Lunux xtensa*-*-linux*
1820 * Change in command line behavior -- corefiles vs. process ids.
1822 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1823 attaching to process NUMBER fails, GDB no longer attempts to open a
1824 core file named NUMBER. Attaching to a program using the -c option
1825 is no longer supported. Instead, use the '-p' or '--pid' options.
1827 * GDB can now be built as a native debugger for debugging Windows x86
1828 (mingw32) Portable Executable (PE) programs.
1830 * Pending breakpoints no longer change their number when their address
1833 * GDB now supports breakpoints with multiple locations,
1834 including breakpoints on C++ constructors, inside C++ templates,
1835 and in inlined functions.
1837 * GDB's ability to debug optimized code has been improved. GDB more
1838 accurately identifies function bodies and lexical blocks that occupy
1839 more than one contiguous range of addresses.
1841 * Target descriptions can now describe registers for PowerPC.
1843 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1844 registers on PowerPC targets.
1846 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1847 targets even when the libthread_db library is not available.
1849 * The GDB remote stub, gdbserver, now supports the new file transfer
1850 commands (remote put, remote get, and remote delete).
1852 * The GDB remote stub, gdbserver, now supports run and attach in
1853 extended-remote mode.
1855 * hppa*64*-*-hpux11* target broken
1856 The debugger is unable to start a program and fails with the following
1857 error: "Error trying to get information about dynamic linker".
1858 The gdb-6.7 release is also affected.
1860 * GDB now supports the --enable-targets= configure option to allow
1861 building a single GDB executable that supports multiple remote
1862 target architectures.
1864 * GDB now supports debugging C and C++ programs which use the
1865 Decimal Floating Point extension. In addition, the PowerPC target
1866 now has a set of pseudo-registers to inspect decimal float values
1867 stored in two consecutive float registers.
1869 * The -break-insert MI command can optionally create pending
1872 * Improved support for debugging Ada
1873 Many improvements to the Ada language support have been made. These
1875 - Better support for Ada2005 interface types
1876 - Improved handling of arrays and slices in general
1877 - Better support for Taft-amendment types
1878 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1880 - Improved command completion in Ada
1883 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1888 set print frame-arguments (all|scalars|none)
1889 show print frame-arguments
1890 The value of this variable can be changed to control which argument
1891 values should be printed by the debugger when displaying a frame.
1896 Transfer files to and from a remote target, and delete remote files.
1903 Transfer files to and from a remote target, and delete remote files.
1905 * New remote packets
1912 Open, close, read, write, and delete files on the remote system.
1915 Attach to an existing process on the remote system, in extended-remote
1919 Run a new process on the remote system, in extended-remote mode.
1921 *** Changes in GDB 6.7
1923 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1924 bfd, libiberty and opcodes, as revealed by static analysis donated by
1925 Coverity, Inc. (http://scan.coverity.com).
1927 * When looking up multiply-defined global symbols, GDB will now prefer the
1928 symbol definition in the current shared library if it was built using the
1929 -Bsymbolic linker option.
1931 * When the Text User Interface (TUI) is not configured, GDB will now
1932 recognize the -tui command-line option and print a message that the TUI
1935 * The GDB remote stub, gdbserver, now has lower overhead for high
1936 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1938 * GDB for MIPS targets now autodetects whether a remote target provides
1939 32-bit or 64-bit register values.
1941 * Support for C++ member pointers has been improved.
1943 * GDB now understands XML target descriptions, which specify the
1944 target's overall architecture. GDB can read a description from
1945 a local file or over the remote serial protocol.
1947 * Vectors of single-byte data use a new integer type which is not
1948 automatically displayed as character or string data.
1950 * The /s format now works with the print command. It displays
1951 arrays of single-byte integers and pointers to single-byte integers
1954 * Target descriptions can now describe target-specific registers,
1955 for architectures which have implemented the support (currently
1956 only ARM, M68K, and MIPS).
1958 * GDB and the GDB remote stub, gdbserver, now support the XScale
1961 * The GDB remote stub, gdbserver, has been updated to support
1962 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1963 has been rewritten to use the standard GDB remote protocol.
1965 * GDB can now step into C++ functions which are called through thunks.
1967 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1969 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1970 layout. It also supports a TextSeg= and DataSeg= response when only
1971 segment base addresses (rather than offsets) are available.
1973 * The /i format now outputs any trailing branch delay slot instructions
1974 immediately following the last instruction within the count specified.
1976 * The GDB remote protocol "T" stop reply packet now supports a
1977 "library" response. Combined with the new "qXfer:libraries:read"
1978 packet, this response allows GDB to debug shared libraries on targets
1979 where the operating system manages the list of loaded libraries (e.g.
1980 Windows and SymbianOS).
1982 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1983 (DLLs) on Windows and Windows CE targets.
1985 * GDB now supports a faster verification that a .debug file matches its binary
1986 according to its build-id signature, if the signature is present.
1992 Enable or disable hardware flow control (RTS/CTS) on the serial port
1993 when debugging using remote targets.
1995 set mem inaccessible-by-default
1996 show mem inaccessible-by-default
1997 If the target supplies a memory map, for instance via the remote
1998 protocol's "qXfer:memory-map:read" packet, setting this variable
1999 prevents GDB from accessing memory outside the memory map. This
2000 is useful for targets with memory mapped registers or which react
2001 badly to accesses of unmapped address space.
2003 set breakpoint auto-hw
2004 show breakpoint auto-hw
2005 If the target supplies a memory map, for instance via the remote
2006 protocol's "qXfer:memory-map:read" packet, setting this variable
2007 lets GDB use hardware breakpoints automatically for memory regions
2008 where it can not use software breakpoints. This covers both the
2009 "break" command and internal breakpoints used for other commands
2010 including "next" and "finish".
2013 catch exception unhandled
2014 Stop the program execution when Ada exceptions are raised.
2017 Stop the program execution when an Ada assertion failed.
2021 Set an alternate system root for target files. This is a more
2022 general version of "set solib-absolute-prefix", which is now
2023 an alias to "set sysroot".
2026 Provide extended SPU facility status information. This set of
2027 commands is available only when debugging the Cell/B.E. SPU
2030 * New native configurations
2032 OpenBSD/sh sh*-*openbsd*
2035 unset tdesc filename
2037 Use the specified local file as an XML target description, and do
2038 not query the target for its built-in description.
2042 OpenBSD/sh sh*-*-openbsd*
2043 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2044 Toshiba Media Processor mep-elf
2046 * New remote packets
2049 Ignore the specified signals; pass them directly to the debugged program
2050 without stopping other threads or reporting them to GDB.
2052 qXfer:features:read:
2053 Read an XML target description from the target, which describes its
2058 Read or write contents of an spufs file on the target system. These
2059 packets are available only on the Cell/B.E. SPU architecture.
2061 qXfer:libraries:read:
2062 Report the loaded shared libraries. Combined with new "T" packet
2063 response, this packet allows GDB to debug shared libraries on
2064 targets where the operating system manages the list of loaded
2065 libraries (e.g. Windows and SymbianOS).
2069 Support for these obsolete configurations has been removed.
2077 i[34567]86-*-lynxos*
2078 i[34567]86-*-netware*
2079 i[34567]86-*-sco3.2v5*
2080 i[34567]86-*-sco3.2v4*
2082 i[34567]86-*-sysv4.2*
2085 i[34567]86-*-unixware2*
2086 i[34567]86-*-unixware*
2095 * Other removed features
2102 Various m68k-only ROM monitors.
2109 Various Renesas ROM monitors and debugging interfaces for SH and
2114 Support for a Macraigor serial interface to on-chip debugging.
2115 GDB does not directly support the newer parallel or USB
2120 A debug information format. The predecessor to DWARF 2 and
2121 DWARF 3, which are still supported.
2123 Support for the HP aCC compiler on HP-UX/PA-RISC
2125 SOM-encapsulated symbolic debugging information, automatic
2126 invocation of pxdb, and the aCC custom C++ ABI. This does not
2127 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2128 with aCC can still be debugged on an assembly level.
2130 MIPS ".pdr" sections
2132 A MIPS-specific format used to describe stack frame layout
2133 in debugging information.
2137 GDB could work with an older version of Guile to debug
2138 the interpreter and Scheme programs running in it.
2140 set mips stack-arg-size
2141 set mips saved-gpreg-size
2143 Use "set mips abi" to control parameter passing for MIPS.
2145 *** Changes in GDB 6.6
2150 Cell Broadband Engine SPU spu-elf
2152 * GDB can now be configured as a cross-debugger targeting native Windows
2153 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2154 running on a Windows system over TCP/IP to debug Windows programs.
2156 * The GDB remote stub, gdbserver, has been updated to support Windows and
2157 Cygwin debugging. Both single-threaded and multi-threaded programs are
2160 * The "set trust-readonly-sections" command works again. This command was
2161 broken in GDB 6.3, 6.4, and 6.5.
2163 * The "load" command now supports writing to flash memory, if the remote
2164 stub provides the required support.
2166 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2167 longer requires symbolic debug information (e.g. DWARF-2).
2172 unset substitute-path
2173 show substitute-path
2174 Manage a list of substitution rules that GDB uses to rewrite the name
2175 of the directories where the sources are located. This can be useful
2176 for instance when the sources were moved to a different location
2177 between compilation and debugging.
2181 Print each CLI command as it is executed. Each command is prefixed with
2182 a number of `+' symbols representing the nesting depth.
2183 The source command now has a `-v' option to enable the same feature.
2187 The ARM Demon monitor support (RDP protocol, "target rdp").
2189 Kernel Object Display, an embedded debugging feature which only worked with
2190 an obsolete version of Cisco IOS.
2192 The 'set download-write-size' and 'show download-write-size' commands.
2194 * New remote packets
2197 Tell a stub about GDB client features, and request remote target features.
2198 The first feature implemented is PacketSize, which allows the target to
2199 specify the size of packets it can handle - to minimize the number of
2200 packets required and improve performance when connected to a remote
2204 Fetch an OS auxilliary vector from the remote stub. This packet is a
2205 more efficient replacement for qPart:auxv:read.
2207 qXfer:memory-map:read:
2208 Fetch a memory map from the remote stub, including information about
2209 RAM, ROM, and flash memory devices.
2214 Erase and program a flash memory device.
2216 * Removed remote packets
2219 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2220 used it, and only gdbserver implemented it.
2222 *** Changes in GDB 6.5
2226 Renesas M32C/M16C m32c-elf
2228 Morpho Technologies ms1 ms1-elf
2232 init-if-undefined Initialize a convenience variable, but
2233 only if it doesn't already have a value.
2235 The following commands are presently only implemented for native GNU/Linux:
2237 checkpoint Save a snapshot of the program state.
2239 restart <n> Return the program state to a
2240 previously saved state.
2242 info checkpoints List currently saved checkpoints.
2244 delete-checkpoint <n> Delete a previously saved checkpoint.
2246 set|show detach-on-fork Tell gdb whether to detach from a newly
2247 forked process, or to keep debugging it.
2249 info forks List forks of the user program that
2250 are available to be debugged.
2252 fork <n> Switch to debugging one of several
2253 forks of the user program that are
2254 available to be debugged.
2256 delete-fork <n> Delete a fork from the list of forks
2257 that are available to be debugged (and
2258 kill the forked process).
2260 detach-fork <n> Delete a fork from the list of forks
2261 that are available to be debugged (and
2262 allow the process to continue).
2266 Morpho Technologies ms2 ms1-elf
2268 * Improved Windows host support
2270 GDB now builds as a cross debugger hosted on i686-mingw32, including
2271 native console support, and remote communications using either
2272 network sockets or serial ports.
2274 * Improved Modula-2 language support
2276 GDB can now print most types in the Modula-2 syntax. This includes:
2277 basic types, set types, record types, enumerated types, range types,
2278 pointer types and ARRAY types. Procedure var parameters are correctly
2279 printed and hexadecimal addresses and character constants are also
2280 written in the Modula-2 syntax. Best results can be obtained by using
2281 GNU Modula-2 together with the -gdwarf-2 command line option.
2285 The ARM rdi-share module.
2287 The Netware NLM debug server.
2289 *** Changes in GDB 6.4
2291 * New native configurations
2293 OpenBSD/arm arm*-*-openbsd*
2294 OpenBSD/mips64 mips64-*-openbsd*
2298 Morpho Technologies ms1 ms1-elf
2300 * New command line options
2302 --batch-silent As for --batch, but totally silent.
2303 --return-child-result The debugger will exist with the same value
2304 the child (debugged) program exited with.
2305 --eval-command COMMAND, -ex COMMAND
2306 Execute a single GDB CLI command. This may be
2307 specified multiple times and in conjunction
2308 with the --command (-x) option.
2310 * Deprecated commands removed
2312 The following commands, that were deprecated in 2000, have been
2316 set|show arm disassembly-flavor set|show arm disassembler
2317 othernames set arm disassembler
2318 set|show remotedebug set|show debug remote
2319 set|show archdebug set|show debug arch
2320 set|show eventdebug set|show debug event
2323 * New BSD user-level threads support
2325 It is now possible to debug programs using the user-level threads
2326 library on OpenBSD and FreeBSD. Currently supported (target)
2329 FreeBSD/amd64 x86_64-*-freebsd*
2330 FreeBSD/i386 i386-*-freebsd*
2331 OpenBSD/i386 i386-*-openbsd*
2333 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2334 are not yet supported.
2336 * New support for Matsushita MN10300 w/sim added
2337 (Work in progress). mn10300-elf.
2339 * REMOVED configurations and files
2341 VxWorks and the XDR protocol *-*-vxworks
2342 Motorola MCORE mcore-*-*
2343 National Semiconductor NS32000 ns32k-*-*
2345 * New "set print array-indexes" command
2347 After turning this setting "on", GDB prints the index of each element
2348 when displaying arrays. The default is "off" to preserve the previous
2351 * VAX floating point support
2353 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2355 * User-defined command support
2357 In addition to using $arg0..$arg9 for argument passing, it is now possible
2358 to use $argc to determine now many arguments have been passed. See the
2359 section on user-defined commands in the user manual for more information.
2361 *** Changes in GDB 6.3:
2363 * New command line option
2365 GDB now accepts -l followed by a number to set the timeout for remote
2368 * GDB works with GCC -feliminate-dwarf2-dups
2370 GDB now supports a more compact representation of DWARF-2 debug
2371 information using DW_FORM_ref_addr references. These are produced
2372 by GCC with the option -feliminate-dwarf2-dups and also by some
2373 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2374 to use -feliminate-dwarf2-dups.
2376 * Internationalization
2378 When supported by the host system, GDB will be built with
2379 internationalization (libintl). The task of marking up the sources is
2380 continued, we're looking forward to our first translation.
2384 Initial support for debugging programs compiled with the GNAT
2385 implementation of the Ada programming language has been integrated
2386 into GDB. In this release, support is limited to expression evaluation.
2388 * New native configurations
2390 GNU/Linux/m32r m32r-*-linux-gnu
2394 GDB's remote protocol now includes support for the 'p' packet. This
2395 packet is used to fetch individual registers from a remote inferior.
2397 * END-OF-LIFE registers[] compatibility module
2399 GDB's internal register infrastructure has been completely rewritten.
2400 The new infrastructure making possible the implementation of key new
2401 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2404 GDB 6.3 will be the last release to include the the registers[]
2405 compatibility module that allowed out-of-date configurations to
2406 continue to work. This change directly impacts the following
2416 powerpc bdm protocol
2418 Unless there is activity to revive these configurations, they will be
2419 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2421 * OBSOLETE configurations and files
2423 Configurations that have been declared obsolete in this release have
2424 been commented out. Unless there is activity to revive these
2425 configurations, the next release of GDB will have their sources
2426 permanently REMOVED.
2435 *** Changes in GDB 6.2.1:
2437 * MIPS `break main; run' gave an heuristic-fence-post warning
2439 When attempting to run even a simple program, a warning about
2440 heuristic-fence-post being hit would be reported. This problem has
2443 * MIPS IRIX 'long double' crashed GDB
2445 When examining a long double variable, GDB would get a segmentation
2446 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2447 IRIX long double values).
2451 A bug in the VAX stack code was causing problems with the "next"
2452 command. This problem has been fixed.
2454 *** Changes in GDB 6.2:
2456 * Fix for ``many threads''
2458 On GNU/Linux systems that use the NPTL threads library, a program
2459 rapidly creating and deleting threads would confuse GDB leading to the
2462 ptrace: No such process.
2463 thread_db_get_info: cannot get thread info: generic error
2465 This problem has been fixed.
2467 * "-async" and "-noasync" options removed.
2469 Support for the broken "-noasync" option has been removed (it caused
2472 * New ``start'' command.
2474 This command runs the program until the begining of the main procedure.
2476 * New BSD Kernel Data Access Library (libkvm) interface
2478 Using ``target kvm'' it is now possible to debug kernel core dumps and
2479 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2480 platforms. Currently supported (native-only) configurations are:
2482 FreeBSD/amd64 x86_64-*-freebsd*
2483 FreeBSD/i386 i?86-*-freebsd*
2484 NetBSD/i386 i?86-*-netbsd*
2485 NetBSD/m68k m68*-*-netbsd*
2486 NetBSD/sparc sparc-*-netbsd*
2487 OpenBSD/amd64 x86_64-*-openbsd*
2488 OpenBSD/i386 i?86-*-openbsd*
2489 OpenBSD/m68k m68*-openbsd*
2490 OpenBSD/sparc sparc-*-openbsd*
2492 * Signal trampoline code overhauled
2494 Many generic problems with GDB's signal handling code have been fixed.
2495 These include: backtraces through non-contiguous stacks; recognition
2496 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2497 call; backtrace through a signal trampoline; step into and out of
2498 signal handlers; and single-stepping in the signal trampoline.
2500 Please note that kernel bugs are a limiting factor here. These
2501 features have been shown to work on an s390 GNU/Linux system that
2502 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2504 * Cygwin support for DWARF 2 added.
2506 * New native configurations
2508 GNU/Linux/hppa hppa*-*-linux*
2509 OpenBSD/hppa hppa*-*-openbsd*
2510 OpenBSD/m68k m68*-*-openbsd*
2511 OpenBSD/m88k m88*-*-openbsd*
2512 OpenBSD/powerpc powerpc-*-openbsd*
2513 NetBSD/vax vax-*-netbsd*
2514 OpenBSD/vax vax-*-openbsd*
2516 * END-OF-LIFE frame compatibility module
2518 GDB's internal frame infrastructure has been completely rewritten.
2519 The new infrastructure making it possible to support key new features
2520 including DWARF 2 Call Frame Information. To aid in the task of
2521 migrating old configurations to this new infrastructure, a
2522 compatibility module, that allowed old configurations to continue to
2523 work, was also included.
2525 GDB 6.2 will be the last release to include this frame compatibility
2526 module. This change directly impacts the following configurations:
2536 Unless there is activity to revive these configurations, they will be
2537 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2539 * REMOVED configurations and files
2541 Sun 3, running SunOS 3 m68*-*-sunos3*
2542 Sun 3, running SunOS 4 m68*-*-sunos4*
2543 Sun 2, running SunOS 3 m68000-*-sunos3*
2544 Sun 2, running SunOS 4 m68000-*-sunos4*
2545 Motorola 680x0 running LynxOS m68*-*-lynxos*
2546 AT&T 3b1/Unix pc m68*-att-*
2547 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2548 decstation mips-dec-* mips-little-*
2549 riscos mips-*-riscos* mips-*-sysv*
2550 sonymips mips-sony-*
2551 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2553 *** Changes in GDB 6.1.1:
2555 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2557 The TUI (Text-mode User Interface) is now built as part of a default
2558 GDB configuration. It is enabled by either selecting the TUI with the
2559 command line option "-i=tui" or by running the separate "gdbtui"
2560 program. For more information on the TUI, see the manual "Debugging
2563 * Pending breakpoint support (also included in GDB 6.1)
2565 Support has been added to allow you to specify breakpoints in shared
2566 libraries that have not yet been loaded. If a breakpoint location
2567 cannot be found, and the "breakpoint pending" option is set to auto,
2568 GDB queries you if you wish to make the breakpoint pending on a future
2569 shared-library load. If and when GDB resolves the breakpoint symbol,
2570 the pending breakpoint is removed as one or more regular breakpoints
2573 Pending breakpoints are very useful for GCJ Java debugging.
2575 * Fixed ISO-C build problems
2577 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2578 non ISO-C code that stopped them being built using a more strict ISO-C
2579 compiler (e.g., IBM's C compiler).
2581 * Fixed build problem on IRIX 5
2583 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2584 wasn't able to compile compile on an IRIX 5 system.
2586 * Added execute permission to gdb/gdbserver/configure
2588 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2589 permission. This bug would cause configure to fail on a number of
2590 systems (Solaris, IRIX). Ref: server/519.
2592 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2594 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2595 has been updated to use constant array sizes.
2597 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2599 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2600 its generated DWARF Call Frame Info. This encoding was causing GDB to
2601 panic, that panic has been fixed. Ref: gdb/1628.
2603 * Fixed a problem when examining parameters in shared library code.
2605 When examining parameters in optimized shared library code generated
2606 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2607 not available''. GDB now correctly displays the variable's value.
2609 *** Changes in GDB 6.1:
2611 * Removed --with-mmalloc
2613 Support for the mmalloc memory manager has been removed, as it
2614 conflicted with the internal gdb byte cache.
2616 * Changes in AMD64 configurations
2618 The AMD64 target now includes the %cs and %ss registers. As a result
2619 the AMD64 remote protocol has changed; this affects the floating-point
2620 and SSE registers. If you rely on those registers for your debugging,
2621 you should upgrade gdbserver on the remote side.
2623 * Revised SPARC target
2625 The SPARC target has been completely revised, incorporating the
2626 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2627 support for LynxOS and SunOS 4 has been dropped. Calling functions
2628 from within GDB on operating systems with a non-executable stack
2629 (Solaris, OpenBSD) now works.
2633 GDB has a new C++ demangler which does a better job on the mangled
2634 names generated by current versions of g++. It also runs faster, so
2635 with this and other changes gdb should now start faster on large C++
2638 * DWARF 2 Location Expressions
2640 GDB support for location expressions has been extended to support function
2641 arguments and frame bases. Older versions of GDB could crash when they
2644 * C++ nested types and namespaces
2646 GDB's support for nested types and namespaces in C++ has been
2647 improved, especially if you use the DWARF 2 debugging format. (This
2648 is the default for recent versions of GCC on most platforms.)
2649 Specifically, if you have a class "Inner" defined within a class or
2650 namespace "Outer", then GDB realizes that the class's name is
2651 "Outer::Inner", not simply "Inner". This should greatly reduce the
2652 frequency of complaints about not finding RTTI symbols. In addition,
2653 if you are stopped at inside of a function defined within a namespace,
2654 GDB modifies its name lookup accordingly.
2656 * New native configurations
2658 NetBSD/amd64 x86_64-*-netbsd*
2659 OpenBSD/amd64 x86_64-*-openbsd*
2660 OpenBSD/alpha alpha*-*-openbsd*
2661 OpenBSD/sparc sparc-*-openbsd*
2662 OpenBSD/sparc64 sparc64-*-openbsd*
2664 * New debugging protocols
2666 M32R with SDI protocol m32r-*-elf*
2668 * "set prompt-escape-char" command deleted.
2670 The command "set prompt-escape-char" has been deleted. This command,
2671 and its very obscure effet on GDB's prompt, was never documented,
2672 tested, nor mentioned in the NEWS file.
2674 * OBSOLETE configurations and files
2676 Configurations that have been declared obsolete in this release have
2677 been commented out. Unless there is activity to revive these
2678 configurations, the next release of GDB will have their sources
2679 permanently REMOVED.
2681 Sun 3, running SunOS 3 m68*-*-sunos3*
2682 Sun 3, running SunOS 4 m68*-*-sunos4*
2683 Sun 2, running SunOS 3 m68000-*-sunos3*
2684 Sun 2, running SunOS 4 m68000-*-sunos4*
2685 Motorola 680x0 running LynxOS m68*-*-lynxos*
2686 AT&T 3b1/Unix pc m68*-att-*
2687 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2688 decstation mips-dec-* mips-little-*
2689 riscos mips-*-riscos* mips-*-sysv*
2690 sonymips mips-sony-*
2691 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2693 * REMOVED configurations and files
2695 SGI Irix-4.x mips-sgi-irix4 or iris4
2696 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2697 Z8000 simulator z8k-zilog-none or z8ksim
2698 Matsushita MN10200 w/simulator mn10200-*-*
2699 H8/500 simulator h8500-hitachi-hms or h8500hms
2700 HP/PA running BSD hppa*-*-bsd*
2701 HP/PA running OSF/1 hppa*-*-osf*
2702 HP/PA Pro target hppa*-*-pro*
2703 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2704 386BSD i[3456]86-*-bsd*
2705 Sequent family i[3456]86-sequent-sysv4*
2706 i[3456]86-sequent-sysv*
2707 i[3456]86-sequent-bsd*
2708 SPARC running LynxOS sparc-*-lynxos*
2709 SPARC running SunOS 4 sparc-*-sunos4*
2710 Tsqware Sparclet sparclet-*-*
2711 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2713 *** Changes in GDB 6.0:
2717 Support for debugging the Objective-C programming language has been
2718 integrated into GDB.
2720 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2722 DWARF 2's Call Frame Information makes available compiler generated
2723 information that more exactly describes the program's run-time stack.
2724 By using this information, GDB is able to provide more robust stack
2727 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2728 have been updated to use a new backtrace mechanism which includes
2729 DWARF 2 CFI support.
2733 GDB's remote protocol has been extended to include support for hosted
2734 file I/O (where the remote target uses GDB's file system). See GDB's
2735 remote protocol documentation for details.
2737 * All targets using the new architecture framework.
2739 All of GDB's targets have been updated to use the new internal
2740 architecture framework. The way is now open for future GDB releases
2741 to include cross-architecture native debugging support (i386 on amd64,
2744 * GNU/Linux's Thread Local Storage (TLS)
2746 GDB now includes support for for the GNU/Linux implementation of
2747 per-thread variables.
2749 * GNU/Linux's Native POSIX Thread Library (NPTL)
2751 GDB's thread code has been updated to work with either the new
2752 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2754 * Separate debug info.
2756 GDB, in conjunction with BINUTILS, now supports a mechanism for
2757 automatically loading debug information from a separate file. Instead
2758 of shipping full debug and non-debug versions of system libraries,
2759 system integrators can now instead ship just the stripped libraries
2760 and optional debug files.
2762 * DWARF 2 Location Expressions
2764 DWARF 2 Location Expressions allow the compiler to more completely
2765 describe the location of variables (even in optimized code) to the
2768 GDB now includes preliminary support for location expressions (support
2769 for DW_OP_piece is still missing).
2773 A number of long standing bugs that caused GDB to die while starting a
2774 Java application have been fixed. GDB's Java support is now
2775 considered "useable".
2777 * GNU/Linux support for fork, vfork, and exec.
2779 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2780 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2783 * GDB supports logging output to a file
2785 There are two new commands, "set logging" and "show logging", which can be
2786 used to capture GDB's output to a file.
2788 * The meaning of "detach" has changed for gdbserver
2790 The "detach" command will now resume the application, as documented. To
2791 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2794 * d10v, m68hc11 `regs' command deprecated
2796 The `info registers' command has been updated so that it displays the
2797 registers using a format identical to the old `regs' command.
2801 A new command, "maint set profile on/off", has been added. This command can
2802 be used to enable or disable profiling while running GDB, to profile a
2803 session or a set of commands. In addition there is a new configure switch,
2804 "--enable-profiling", which will cause GDB to be compiled with profiling
2805 data, for more informative profiling results.
2807 * Default MI syntax changed to "mi2".
2809 The default MI (machine interface) syntax, enabled by the command line
2810 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2811 "mi1", can be enabled by specifying the option "-i=mi1".
2813 Support for the original "mi0" syntax (included in GDB 5.0) has been
2816 Fix for gdb/192: removed extraneous space when displaying frame level.
2817 Fix for gdb/672: update changelist is now output in mi list format.
2818 Fix for gdb/702: a -var-assign that updates the value now shows up
2819 in a subsequent -var-update.
2821 * New native configurations.
2823 FreeBSD/amd64 x86_64-*-freebsd*
2825 * Multi-arched targets.
2827 HP/PA HPUX11 hppa*-*-hpux*
2828 Renesas M32R/D w/simulator m32r-*-elf*
2830 * OBSOLETE configurations and files
2832 Configurations that have been declared obsolete in this release have
2833 been commented out. Unless there is activity to revive these
2834 configurations, the next release of GDB will have their sources
2835 permanently REMOVED.
2837 Z8000 simulator z8k-zilog-none or z8ksim
2838 Matsushita MN10200 w/simulator mn10200-*-*
2839 H8/500 simulator h8500-hitachi-hms or h8500hms
2840 HP/PA running BSD hppa*-*-bsd*
2841 HP/PA running OSF/1 hppa*-*-osf*
2842 HP/PA Pro target hppa*-*-pro*
2843 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2844 Sequent family i[3456]86-sequent-sysv4*
2845 i[3456]86-sequent-sysv*
2846 i[3456]86-sequent-bsd*
2847 Tsqware Sparclet sparclet-*-*
2848 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2850 * REMOVED configurations and files
2853 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2854 IBM AIX PS/2 i[3456]86-*-aix
2855 i386 running Mach 3.0 i[3456]86-*-mach3*
2856 i386 running Mach i[3456]86-*-mach*
2857 i386 running OSF/1 i[3456]86-*osf1mk*
2858 HP/Apollo 68k Family m68*-apollo*-sysv*,
2860 m68*-hp-bsd*, m68*-hp-hpux*
2861 Argonaut Risc Chip (ARC) arc-*-*
2862 Mitsubishi D30V d30v-*-*
2863 Fujitsu FR30 fr30-*-elf*
2864 OS/9000 i[34]86-*-os9k
2865 I960 with MON960 i960-*-coff
2867 * MIPS $fp behavior changed
2869 The convenience variable $fp, for the MIPS, now consistently returns
2870 the address of the current frame's base. Previously, depending on the
2871 context, $fp could refer to either $sp or the current frame's base
2872 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2873 The GNU Source-Level Debugger''.
2875 *** Changes in GDB 5.3:
2877 * GNU/Linux shared library multi-threaded performance improved.
2879 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2880 `/proc', in preference to `ptrace' for memory reads. This may result
2881 in an improvement in the start-up time of multi-threaded, shared
2882 library applications when run under GDB. One GDB user writes: ``loads
2883 shared libs like mad''.
2885 * ``gdbserver'' now supports multi-threaded applications on some targets
2887 Support for debugging multi-threaded applications which use
2888 the GNU/Linux LinuxThreads package has been added for
2889 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2890 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2892 * GDB now supports C/C++ preprocessor macros.
2894 GDB now expands preprocessor macro invocations in C/C++ expressions,
2895 and provides various commands for showing macro definitions and how
2898 The new command `macro expand EXPRESSION' expands any macro
2899 invocations in expression, and shows the result.
2901 The new command `show macro MACRO-NAME' shows the definition of the
2902 macro named MACRO-NAME, and where it was defined.
2904 Most compilers don't include information about macros in the debugging
2905 information by default. In GCC 3.1, for example, you need to compile
2906 your program with the options `-gdwarf-2 -g3'. If the macro
2907 information is present in the executable, GDB will read it.
2909 * Multi-arched targets.
2911 DEC Alpha (partial) alpha*-*-*
2912 DEC VAX (partial) vax-*-*
2914 National Semiconductor NS32000 (partial) ns32k-*-*
2915 Motorola 68000 (partial) m68k-*-*
2916 Motorola MCORE mcore-*-*
2920 Fujitsu FRV architecture added by Red Hat frv*-*-*
2923 * New native configurations
2925 Alpha NetBSD alpha*-*-netbsd*
2926 SH NetBSD sh*-*-netbsdelf*
2927 MIPS NetBSD mips*-*-netbsd*
2928 UltraSPARC NetBSD sparc64-*-netbsd*
2930 * OBSOLETE configurations and files
2932 Configurations that have been declared obsolete in this release have
2933 been commented out. Unless there is activity to revive these
2934 configurations, the next release of GDB will have their sources
2935 permanently REMOVED.
2937 Mitsubishi D30V d30v-*-*
2938 OS/9000 i[34]86-*-os9k
2939 IBM AIX PS/2 i[3456]86-*-aix
2940 Fujitsu FR30 fr30-*-elf*
2941 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2942 Argonaut Risc Chip (ARC) arc-*-*
2943 i386 running Mach 3.0 i[3456]86-*-mach3*
2944 i386 running Mach i[3456]86-*-mach*
2945 i386 running OSF/1 i[3456]86-*osf1mk*
2946 HP/Apollo 68k Family m68*-apollo*-sysv*,
2948 m68*-hp-bsd*, m68*-hp-hpux*
2949 I960 with MON960 i960-*-coff
2951 * OBSOLETE languages
2953 CHILL, a Pascal like language used by telecommunications companies.
2955 * REMOVED configurations and files
2957 AMD 29k family via UDI a29k-amd-udi, udi29k
2958 A29K VxWorks a29k-*-vxworks
2959 AMD 29000 embedded, using EBMON a29k-none-none
2960 AMD 29000 embedded with COFF a29k-none-coff
2961 AMD 29000 embedded with a.out a29k-none-aout
2963 testsuite/gdb.hp/gdb.threads-hp/ directory
2965 * New command "set max-user-call-depth <nnn>"
2967 This command allows the user to limit the call depth of user-defined
2968 commands. The default is 1024.
2970 * Changes in FreeBSD/i386 native debugging.
2972 Support for the "generate-core-file" has been added.
2974 * New commands "dump", "append", and "restore".
2976 These commands allow data to be copied from target memory
2977 to a bfd-format or binary file (dump and append), and back
2978 from a file into memory (restore).
2980 * Improved "next/step" support on multi-processor Alpha Tru64.
2982 The previous single-step mechanism could cause unpredictable problems,
2983 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2984 of a software single-step mechanism prevents this.
2986 *** Changes in GDB 5.2.1:
2994 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2995 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2996 Fix, by Joel Brobecker imported from mainline.
2998 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2999 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3000 Fix, by Fred Fish, imported from mainline.
3002 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3003 Surprisingly enough, it works now.
3004 By Michal Ludvig, imported from mainline.
3006 i386 hardware watchpoint support:
3007 avoid misses on second run for some targets.
3008 By Pierre Muller, imported from mainline.
3010 *** Changes in GDB 5.2:
3012 * New command "set trust-readonly-sections on[off]".
3014 This command is a hint that tells gdb that read-only sections
3015 really are read-only (ie. that their contents will not change).
3016 In this mode, gdb will go to the object file rather than the
3017 target to read memory from read-only sections (such as ".text").
3018 This can be a significant performance improvement on some
3019 (notably embedded) targets.
3021 * New command "generate-core-file" (or "gcore").
3023 This new gdb command allows the user to drop a core file of the child
3024 process state at any time. So far it's been implemented only for
3025 GNU/Linux and Solaris, but should be relatively easily ported to other
3026 hosts. Argument is core file name (defaults to core.<pid>).
3028 * New command line option
3030 GDB now accepts --pid or -p followed by a process id.
3032 * Change in command line behavior -- corefiles vs. process ids.
3034 There is a subtle behavior in the way in which GDB handles
3035 command line arguments. The first non-flag argument is always
3036 a program to debug, but the second non-flag argument may either
3037 be a corefile or a process id. Previously, GDB would attempt to
3038 open the second argument as a corefile, and if that failed, would
3039 issue a superfluous error message and then attempt to attach it as
3040 a process. Now, if the second argument begins with a non-digit,
3041 it will be treated as a corefile. If it begins with a digit,
3042 GDB will attempt to attach it as a process, and if no such process
3043 is found, will then attempt to open it as a corefile.
3045 * Changes in ARM configurations.
3047 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3048 configuration is fully multi-arch.
3050 * New native configurations
3052 ARM NetBSD arm*-*-netbsd*
3053 x86 OpenBSD i[3456]86-*-openbsd*
3054 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3055 Sparc64 running FreeBSD sparc64-*-freebsd*
3059 Sanyo XStormy16 xstormy16-elf
3061 * OBSOLETE configurations and files
3063 Configurations that have been declared obsolete in this release have
3064 been commented out. Unless there is activity to revive these
3065 configurations, the next release of GDB will have their sources
3066 permanently REMOVED.
3068 AMD 29k family via UDI a29k-amd-udi, udi29k
3069 A29K VxWorks a29k-*-vxworks
3070 AMD 29000 embedded, using EBMON a29k-none-none
3071 AMD 29000 embedded with COFF a29k-none-coff
3072 AMD 29000 embedded with a.out a29k-none-aout
3074 testsuite/gdb.hp/gdb.threads-hp/ directory
3076 * REMOVED configurations and files
3078 TI TMS320C80 tic80-*-*
3080 PowerPC Solaris powerpcle-*-solaris*
3081 PowerPC Windows NT powerpcle-*-cygwin32
3082 PowerPC Netware powerpc-*-netware*
3083 Harris/CXUX m88k m88*-harris-cxux*
3084 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3085 ns32k-utek-sysv* ns32k-utek-*
3086 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3087 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3088 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3089 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3090 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3092 * Changes to command line processing
3094 The new `--args' feature can be used to specify command-line arguments
3095 for the inferior from gdb's command line.
3097 * Changes to key bindings
3099 There is a new `operate-and-get-next' function bound to `C-o'.
3101 *** Changes in GDB 5.1.1
3103 Fix compile problem on DJGPP.
3105 Fix a problem with floating-point registers on the i386 being
3108 Fix to stop GDB crashing on .debug_str debug info.
3110 Numerous documentation fixes.
3112 Numerous testsuite fixes.
3114 *** Changes in GDB 5.1:
3116 * New native configurations
3118 Alpha FreeBSD alpha*-*-freebsd*
3119 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3120 MIPS GNU/Linux mips*-*-linux*
3121 MIPS SGI Irix 6.x mips*-sgi-irix6*
3122 ia64 AIX ia64-*-aix*
3123 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3127 Motorola 68HC11 and 68HC12 m68hc11-elf
3129 UltraSparc running GNU/Linux sparc64-*-linux*
3131 * OBSOLETE configurations and files
3133 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3134 Harris/CXUX m88k m88*-harris-cxux*
3135 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3136 ns32k-utek-sysv* ns32k-utek-*
3137 TI TMS320C80 tic80-*-*
3139 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3140 PowerPC Solaris powerpcle-*-solaris*
3141 PowerPC Windows NT powerpcle-*-cygwin32
3142 PowerPC Netware powerpc-*-netware*
3143 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3144 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3145 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3146 Apple Macintosh (MPW) host N/A
3148 stuff.c (Program to stuff files into a specially prepared space in kdb)
3149 kdb-start.c (Main loop for the standalone kernel debugger)
3151 Configurations that have been declared obsolete in this release have
3152 been commented out. Unless there is activity to revive these
3153 configurations, the next release of GDB will have their sources
3154 permanently REMOVED.
3156 * REMOVED configurations and files
3158 Altos 3068 m68*-altos-*
3159 Convex c1-*-*, c2-*-*
3161 ARM RISCix arm-*-* (as host)
3165 * GDB has been converted to ISO C.
3167 GDB's source code has been converted to ISO C. In particular, the
3168 sources are fully protoized, and rely on standard headers being
3173 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3175 * The MI enabled by default.
3177 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3178 revised and enabled by default. Packages which use GDB as a debugging
3179 engine behind a UI or another front end are encouraged to switch to
3180 using the GDB/MI interface, instead of the old annotations interface
3181 which is now deprecated.
3183 * Support for debugging Pascal programs.
3185 GDB now includes support for debugging Pascal programs. The following
3186 main features are supported:
3188 - Pascal-specific data types such as sets;
3190 - automatic recognition of Pascal sources based on file-name
3193 - Pascal-style display of data types, variables, and functions;
3195 - a Pascal expression parser.
3197 However, some important features are not yet supported.
3199 - Pascal string operations are not supported at all;
3201 - there are some problems with boolean types;
3203 - Pascal type hexadecimal constants are not supported
3204 because they conflict with the internal variables format;
3206 - support for Pascal objects and classes is not full yet;
3208 - unlike Pascal, GDB is case-sensitive for symbol names.
3210 * Changes in completion.
3212 Commands such as `shell', `run' and `set args', which pass arguments
3213 to inferior programs, now complete on file names, similar to what
3214 users expect at the shell prompt.
3216 Commands which accept locations, such as `disassemble', `print',
3217 `breakpoint', `until', etc. now complete on filenames as well as
3218 program symbols. Thus, if you type "break foob TAB", and the source
3219 files linked into the programs include `foobar.c', that file name will
3220 be one of the candidates for completion. However, file names are not
3221 considered for completion after you typed a colon that delimits a file
3222 name from a name of a function in that file, as in "break foo.c:bar".
3224 `set demangle-style' completes on available demangling styles.
3226 * New platform-independent commands:
3228 It is now possible to define a post-hook for a command as well as a
3229 hook that runs before the command. For more details, see the
3230 documentation of `hookpost' in the GDB manual.
3232 * Changes in GNU/Linux native debugging.
3234 Support for debugging multi-threaded programs has been completely
3235 revised for all platforms except m68k and sparc. You can now debug as
3236 many threads as your system allows you to have.
3238 Attach/detach is supported for multi-threaded programs.
3240 Support for SSE registers was added for x86. This doesn't work for
3241 multi-threaded programs though.
3243 * Changes in MIPS configurations.
3245 Multi-arch support is enabled for all MIPS configurations.
3247 GDB can now be built as native debugger on SGI Irix 6.x systems for
3248 debugging n32 executables. (Debugging 64-bit executables is not yet
3251 * Unified support for hardware watchpoints in all x86 configurations.
3253 Most (if not all) native x86 configurations support hardware-assisted
3254 breakpoints and watchpoints in a unified manner. This support
3255 implements debug register sharing between watchpoints, which allows to
3256 put a virtually infinite number of watchpoints on the same address,
3257 and also supports watching regions up to 16 bytes with several debug
3260 The new maintenance command `maintenance show-debug-regs' toggles
3261 debugging print-outs in functions that insert, remove, and test
3262 watchpoints and hardware breakpoints.
3264 * Changes in the DJGPP native configuration.
3266 New command ``info dos sysinfo'' displays assorted information about
3267 the CPU, OS, memory, and DPMI server.
3269 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3270 display information about segment descriptors stored in GDT, LDT, and
3273 New commands ``info dos pde'' and ``info dos pte'' display entries
3274 from Page Directory and Page Tables (for now works with CWSDPMI only).
3275 New command ``info dos address-pte'' displays the Page Table entry for
3276 a given linear address.
3278 GDB can now pass command lines longer than 126 characters to the
3279 program being debugged (requires an update to the libdbg.a library
3280 which is part of the DJGPP development kit).
3282 DWARF2 debug info is now supported.
3284 It is now possible to `step' and `next' through calls to `longjmp'.
3286 * Changes in documentation.
3288 All GDB documentation was converted to GFDL, the GNU Free
3289 Documentation License.
3291 Tracepoints-related commands are now fully documented in the GDB
3294 TUI, the Text-mode User Interface, is now documented in the manual.
3296 Tracepoints-related commands are now fully documented in the GDB
3299 The "GDB Internals" manual now has an index. It also includes
3300 documentation of `ui_out' functions, GDB coding standards, x86
3301 hardware watchpoints, and memory region attributes.
3303 * GDB's version number moved to ``version.in''
3305 The Makefile variable VERSION has been replaced by the file
3306 ``version.in''. People creating GDB distributions should update the
3307 contents of this file.
3311 GUD support is now a standard part of the EMACS distribution.
3313 *** Changes in GDB 5.0:
3315 * Improved support for debugging FP programs on x86 targets
3317 Unified and much-improved support for debugging floating-point
3318 programs on all x86 targets. In particular, ``info float'' now
3319 displays the FP registers in the same format on all x86 targets, with
3320 greater level of detail.
3322 * Improvements and bugfixes in hardware-assisted watchpoints
3324 It is now possible to watch array elements, struct members, and
3325 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3326 on x86 targets no longer erroneously trigger when the address is
3329 * Improvements in the native DJGPP version of GDB
3331 The distribution now includes all the scripts and auxiliary files
3332 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3333 machines ``out of the box''.
3335 The DJGPP version can now debug programs that use signals. It is
3336 possible to catch signals that happened in the debuggee, deliver
3337 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3338 would kill the program being debugged.) Programs that hook hardware
3339 interrupts (keyboard, timer, etc.) can also be debugged.
3341 It is now possible to debug DJGPP programs that redirect their
3342 standard handles or switch them to raw (as opposed to cooked) mode, or
3343 even close them. The command ``run < foo > bar'' works as expected,
3344 and ``info terminal'' reports useful information about the debuggee's
3345 terminal, including raw/cooked mode, redirection, etc.
3347 The DJGPP version now uses termios functions for console I/O, which
3348 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3351 DOS-style file names with drive letters are now fully supported by
3354 It is now possible to debug DJGPP programs that switch their working
3355 directory. It is also possible to rerun the debuggee any number of
3356 times without restarting GDB; thus, you can use the same setup,
3357 breakpoints, etc. for many debugging sessions.
3359 * New native configurations
3361 ARM GNU/Linux arm*-*-linux*
3362 PowerPC GNU/Linux powerpc-*-linux*
3366 Motorola MCore mcore-*-*
3367 x86 VxWorks i[3456]86-*-vxworks*
3368 PowerPC VxWorks powerpc-*-vxworks*
3369 TI TMS320C80 tic80-*-*
3371 * OBSOLETE configurations
3373 Altos 3068 m68*-altos-*
3374 Convex c1-*-*, c2-*-*
3376 ARM RISCix arm-*-* (as host)
3379 Configurations that have been declared obsolete will be commented out,
3380 but the code will be left in place. If there is no activity to revive
3381 these configurations before the next release of GDB, the sources will
3382 be permanently REMOVED.
3384 * Gould support removed
3386 Support for the Gould PowerNode and NP1 has been removed.
3388 * New features for SVR4
3390 On SVR4 native platforms (such as Solaris), if you attach to a process
3391 without first loading a symbol file, GDB will now attempt to locate and
3392 load symbols from the running process's executable file.
3394 * Many C++ enhancements
3396 C++ support has been greatly improved. Overload resolution now works properly
3397 in almost all cases. RTTI support is on the way.
3399 * Remote targets can connect to a sub-program
3401 A popen(3) style serial-device has been added. This device starts a
3402 sub-process (such as a stand-alone simulator) and then communicates
3403 with that. The sub-program to run is specified using the syntax
3404 ``|<program> <args>'' vis:
3406 (gdb) set remotedebug 1
3407 (gdb) target extended-remote |mn10300-elf-sim program-args
3409 * MIPS 64 remote protocol
3411 A long standing bug in the mips64 remote protocol where by GDB
3412 expected certain 32 bit registers (ex SR) to be transfered as 32
3413 instead of 64 bits has been fixed.
3415 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3416 added to provide backward compatibility with older versions of GDB.
3418 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3420 The command ``set remotebinarydownload'' command has been replaced by
3421 ``set remote X-packet''. Other commands in ``set remote'' family
3422 include ``set remote P-packet''.
3424 * Breakpoint commands accept ranges.
3426 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3427 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3428 ``tracepoint passcount'' also accepts a range of tracepoints.
3430 * ``apropos'' command added.
3432 The ``apropos'' command searches through command names and
3433 documentation strings, printing out matches, making it much easier to
3434 try to find a command that does what you are looking for.
3438 A new machine oriented interface (MI) has been added to GDB. This
3439 interface is designed for debug environments running GDB as a separate
3440 process. This is part of the long term libGDB project. See the
3441 "GDB/MI" chapter of the GDB manual for further information. It can be
3442 enabled by configuring with:
3444 .../configure --enable-gdbmi
3446 *** Changes in GDB-4.18:
3448 * New native configurations
3450 HP-UX 10.20 hppa*-*-hpux10.20
3451 HP-UX 11.x hppa*-*-hpux11.0*
3452 M68K GNU/Linux m68*-*-linux*
3456 Fujitsu FR30 fr30-*-elf*
3457 Intel StrongARM strongarm-*-*
3458 Mitsubishi D30V d30v-*-*
3460 * OBSOLETE configurations
3462 Gould PowerNode, NP1 np1-*-*, pn-*-*
3464 Configurations that have been declared obsolete will be commented out,
3465 but the code will be left in place. If there is no activity to revive
3466 these configurations before the next release of GDB, the sources will
3467 be permanently REMOVED.
3471 As a compatibility experiment, GDB's source files buildsym.h and
3472 buildsym.c have been converted to pure standard C, no longer
3473 containing any K&R compatibility code. We believe that all systems in
3474 use today either come with a standard C compiler, or have a GCC port
3475 available. If this is not true, please report the affected
3476 configuration to bug-gdb@gnu.org immediately. See the README file for
3477 information about getting a standard C compiler if you don't have one
3482 GDB now uses readline 2.2.
3484 * set extension-language
3486 You can now control the mapping between filename extensions and source
3487 languages by using the `set extension-language' command. For instance,
3488 you can ask GDB to treat .c files as C++ by saying
3489 set extension-language .c c++
3490 The command `info extensions' lists all of the recognized extensions
3491 and their associated languages.
3493 * Setting processor type for PowerPC and RS/6000
3495 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3496 you can use the `set processor' command to specify what variant of the
3497 PowerPC family you are debugging. The command
3501 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3502 following PowerPC and RS6000 variants:
3504 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3505 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3507 403GC IBM PowerPC 403GC
3508 505 Motorola PowerPC 505
3509 860 Motorola PowerPC 860 or 850
3510 601 Motorola PowerPC 601
3511 602 Motorola PowerPC 602
3512 603 Motorola/IBM PowerPC 603 or 603e
3513 604 Motorola PowerPC 604 or 604e
3514 750 Motorola/IBM PowerPC 750 or 750
3516 At the moment, this command just tells GDB what to name the
3517 special-purpose processor registers. Since almost all the affected
3518 registers are inaccessible to user-level programs, this command is
3519 only useful for remote debugging in its present form.
3523 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3524 more extensive support for HP-UX. Added features include shared
3525 library support, kernel threads and hardware watchpoints for 11.00,
3526 support for HP's ANSI C and C++ compilers, and a compatibility mode
3527 for xdb and dbx commands.
3531 HP's donation includes the new concept of catchpoints, which is a
3532 generalization of the old catch command. On HP-UX, it is now possible
3533 to catch exec, fork, and vfork, as well as library loading.
3535 This means that the existing catch command has changed; its first
3536 argument now specifies the type of catch to be set up. See the
3537 output of "help catch" for a list of catchpoint types.
3539 * Debugging across forks
3541 On HP-UX, you can choose which process to debug when a fork() happens
3546 HP has donated a curses-based terminal user interface (TUI). To get
3547 it, build with --enable-tui. Although this can be enabled for any
3548 configuration, at present it only works for native HP debugging.
3550 * GDB remote protocol additions
3552 A new protocol packet 'X' that writes binary data is now available.
3553 Default behavior is to try 'X', then drop back to 'M' if the stub
3554 fails to respond. The settable variable `remotebinarydownload'
3555 allows explicit control over the use of 'X'.
3557 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3558 full 64-bit address. The command
3560 set remoteaddresssize 32
3562 can be used to revert to the old behaviour. For existing remote stubs
3563 the change should not be noticed, as the additional address information
3566 In order to assist in debugging stubs, you may use the maintenance
3567 command `packet' to send any text string to the stub. For instance,
3569 maint packet heythere
3571 sends the packet "$heythere#<checksum>". Note that it is very easy to
3572 disrupt a debugging session by sending the wrong packet at the wrong
3575 The compare-sections command allows you to compare section data on the
3576 target to what is in the executable file without uploading or
3577 downloading, by comparing CRC checksums.
3579 * Tracing can collect general expressions
3581 You may now collect general expressions at tracepoints. This requires
3582 further additions to the target-side stub; see tracepoint.c and
3583 doc/agentexpr.texi for further details.
3585 * mask-address variable for Mips
3587 For Mips targets, you may control the zeroing of the upper 32 bits of
3588 a 64-bit address by entering `set mask-address on'. This is mainly
3589 of interest to users of embedded R4xxx and R5xxx processors.
3591 * Higher serial baud rates
3593 GDB's serial code now allows you to specify baud rates 57600, 115200,
3594 230400, and 460800 baud. (Note that your host system may not be able
3595 to achieve all of these rates.)
3599 The i960 configuration now includes an initial implementation of a
3600 builtin simulator, contributed by Jim Wilson.
3603 *** Changes in GDB-4.17:
3605 * New native configurations
3607 Alpha GNU/Linux alpha*-*-linux*
3608 Unixware 2.x i[3456]86-unixware2*
3609 Irix 6.x mips*-sgi-irix6*
3610 PowerPC GNU/Linux powerpc-*-linux*
3611 PowerPC Solaris powerpcle-*-solaris*
3612 Sparc GNU/Linux sparc-*-linux*
3613 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3617 Argonaut Risc Chip (ARC) arc-*-*
3618 Hitachi H8/300S h8300*-*-*
3619 Matsushita MN10200 w/simulator mn10200-*-*
3620 Matsushita MN10300 w/simulator mn10300-*-*
3621 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3622 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3623 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3624 Mitsubishi D10V w/simulator d10v-*-*
3625 Mitsubishi M32R/D w/simulator m32r-*-elf*
3626 Tsqware Sparclet sparclet-*-*
3627 NEC V850 w/simulator v850-*-*
3629 * New debugging protocols
3631 ARM with RDI protocol arm*-*-*
3632 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3633 DDB and LSI variants of PMON protocol mips*-*-*
3634 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3635 PowerPC with SDS protocol powerpc{,le}-*-eabi
3636 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3640 All configurations can now understand and use the DWARF 2 debugging
3641 format. The choice is automatic, if the symbol file contains DWARF 2
3646 GDB now includes basic Java language support. This support is
3647 only useful with Java compilers that produce native machine code.
3649 * solib-absolute-prefix and solib-search-path
3651 For SunOS and SVR4 shared libraries, you may now set the prefix for
3652 loading absolute shared library symbol files, and the search path for
3653 locating non-absolute shared library symbol files.
3655 * Live range splitting
3657 GDB can now effectively debug code for which GCC has performed live
3658 range splitting as part of its optimization. See gdb/doc/LRS for
3659 more details on the expected format of the stabs information.
3663 GDB's support for the GNU Hurd, including thread debugging, has been
3664 updated to work with current versions of the Hurd.
3668 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3669 instruction set. ARM GDB automatically detects when Thumb
3670 instructions are in use, and adjusts disassembly and backtracing
3675 GDB's MIPS target configurations now handle the MIP16 16-bit
3680 GDB now includes support for overlays; if an executable has been
3681 linked such that multiple sections are based at the same address, GDB
3682 will decide which section to use for symbolic info. You can choose to
3683 control the decision manually, using overlay commands, or implement
3684 additional target-side support and use "overlay load-target" to bring
3685 in the overlay mapping. Do "help overlay" for more detail.
3689 The command "info symbol <address>" displays information about
3690 the symbol at the specified address.
3694 The standard remote protocol now includes an extension that allows
3695 asynchronous collection and display of trace data. This requires
3696 extensive support in the target-side debugging stub. Tracing mode
3697 includes a new interaction mode in GDB and new commands: see the
3698 file tracepoint.c for more details.
3702 Configurations for embedded MIPS now include a simulator contributed
3703 by Cygnus Solutions. The simulator supports the instruction sets
3704 of most MIPS variants.
3708 Sparc configurations may now include the ERC32 simulator contributed
3709 by the European Space Agency. The simulator is not built into
3710 Sparc targets by default; configure with --enable-sim to include it.
3714 For target configurations that may include multiple variants of a
3715 basic architecture (such as MIPS and SH), you may now set the
3716 architecture explicitly. "set arch" sets, "info arch" lists
3717 the possible architectures.
3719 *** Changes in GDB-4.16:
3721 * New native configurations
3723 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3724 M68K NetBSD m68k-*-netbsd*
3725 PowerPC AIX 4.x powerpc-*-aix*
3726 PowerPC MacOS powerpc-*-macos*
3727 PowerPC Windows NT powerpcle-*-cygwin32
3728 RS/6000 AIX 4.x rs6000-*-aix4*
3732 ARM with RDP protocol arm-*-*
3733 I960 with MON960 i960-*-coff
3734 MIPS VxWorks mips*-*-vxworks*
3735 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3736 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3738 Matra Sparclet sparclet-*-*
3742 The powerpc-eabi configuration now includes the PSIM simulator,
3743 contributed by Andrew Cagney, with assistance from Mike Meissner.
3744 PSIM is a very elaborate model of the PowerPC, including not only
3745 basic instruction set execution, but also details of execution unit
3746 performance and I/O hardware. See sim/ppc/README for more details.
3750 GDB now works with Solaris 2.5.
3752 * Windows 95/NT native
3754 GDB will now work as a native debugger on Windows 95 and Windows NT.
3755 To build it from source, you must use the "gnu-win32" environment,
3756 which uses a DLL to emulate enough of Unix to run the GNU tools.
3757 Further information, binaries, and sources are available at
3758 ftp.cygnus.com, under pub/gnu-win32.
3760 * dont-repeat command
3762 If a user-defined command includes the command `dont-repeat', then the
3763 command will not be repeated if the user just types return. This is
3764 useful if the command is time-consuming to run, so that accidental
3765 extra keystrokes don't run the same command many times.
3767 * Send break instead of ^C
3769 The standard remote protocol now includes an option to send a break
3770 rather than a ^C to the target in order to interrupt it. By default,
3771 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3773 * Remote protocol timeout
3775 The standard remote protocol includes a new variable `remotetimeout'
3776 that allows you to set the number of seconds before GDB gives up trying
3777 to read from the target. The default value is 2.
3779 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3781 By default GDB will automatically keep track of objects as they are
3782 loaded and unloaded by the dynamic linker. By using the command `set
3783 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3784 when shared library events occur, thus allowing you to set breakpoints
3785 in shared libraries which are explicitly loaded by the inferior.
3787 Note this feature does not work on hpux8. On hpux9 you must link
3788 /usr/lib/end.o into your program. This feature should work
3789 automatically on hpux10.
3791 * Irix 5.x hardware watchpoint support
3793 Irix 5 configurations now support the use of hardware watchpoints.
3795 * Mips protocol "SYN garbage limit"
3797 When debugging a Mips target using the `target mips' protocol, you
3798 may set the number of characters that GDB will ignore by setting
3799 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3800 every character. The default value is 1050.
3802 * Recording and replaying remote debug sessions
3804 If you set `remotelogfile' to the name of a file, gdb will write to it
3805 a recording of a remote debug session. This recording may then be
3806 replayed back to gdb using "gdbreplay". See gdbserver/README for
3807 details. This is useful when you have a problem with GDB while doing
3808 remote debugging; you can make a recording of the session and send it
3809 to someone else, who can then recreate the problem.
3811 * Speedups for remote debugging
3813 GDB includes speedups for downloading and stepping MIPS systems using
3814 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3815 and more efficient S-record downloading.
3817 * Memory use reductions and statistics collection
3819 GDB now uses less memory and reports statistics about memory usage.
3820 Try the `maint print statistics' command, for example.
3822 *** Changes in GDB-4.15:
3824 * Psymtabs for XCOFF
3826 The symbol reader for AIX GDB now uses partial symbol tables. This
3827 can greatly improve startup time, especially for large executables.
3829 * Remote targets use caching
3831 Remote targets now use a data cache to speed up communication with the
3832 remote side. The data cache could lead to incorrect results because
3833 it doesn't know about volatile variables, thus making it impossible to
3834 debug targets which use memory mapped I/O devices. `set remotecache
3835 off' turns the the data cache off.
3837 * Remote targets may have threads
3839 The standard remote protocol now includes support for multiple threads
3840 in the target system, using new protocol commands 'H' and 'T'. See
3841 gdb/remote.c for details.
3845 If GDB is configured with `--enable-netrom', then it will include
3846 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3847 acts as though it is a bank of ROM on the target board, but you can
3848 write into it over the network. GDB's support consists only of
3849 support for fast loading into the emulated ROM; to debug, you must use
3850 another protocol, such as standard remote protocol. The usual
3851 sequence is something like
3853 target nrom <netrom-hostname>
3855 target remote <netrom-hostname>:1235
3859 GDB now includes support for the Apple Macintosh, as a host only. It
3860 may be run as either an MPW tool or as a standalone application, and
3861 it can debug through the serial port. All the usual GDB commands are
3862 available, but to the target command, you must supply "serial" as the
3863 device type instead of "/dev/ttyXX". See mpw-README in the main
3864 directory for more information on how to build. The MPW configuration
3865 scripts */mpw-config.in support only a few targets, and only the
3866 mips-idt-ecoff target has been tested.
3870 GDB configuration now uses autoconf. This is not user-visible,
3871 but does simplify configuration and building.
3875 GDB now supports hpux10.
3877 *** Changes in GDB-4.14:
3879 * New native configurations
3881 x86 FreeBSD i[345]86-*-freebsd
3882 x86 NetBSD i[345]86-*-netbsd
3883 NS32k NetBSD ns32k-*-netbsd
3884 Sparc NetBSD sparc-*-netbsd
3888 A29K VxWorks a29k-*-vxworks
3889 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3890 CPU32 EST-300 emulator m68*-*-est*
3891 PowerPC ELF powerpc-*-elf
3894 * Alpha OSF/1 support for procfs
3896 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3897 possible to attach to running processes. As the mounting of the /proc
3898 filesystem is optional on the Alpha, GDB automatically determines
3899 the availability of /proc during startup. This can lead to problems
3900 if /proc is unmounted after GDB has been started.
3902 * Arguments to user-defined commands
3904 User commands may accept up to 10 arguments separated by whitespace.
3905 Arguments are accessed within the user command via $arg0..$arg9. A
3908 print $arg0 + $arg1 + $arg2
3910 To execute the command use:
3913 Defines the command "adder" which prints the sum of its three arguments.
3914 Note the arguments are text substitutions, so they may reference variables,
3915 use complex expressions, or even perform inferior function calls.
3917 * New `if' and `while' commands
3919 This makes it possible to write more sophisticated user-defined
3920 commands. Both commands take a single argument, which is the
3921 expression to evaluate, and must be followed by the commands to
3922 execute, one per line, if the expression is nonzero, the list being
3923 terminated by the word `end'. The `if' command list may include an
3924 `else' word, which causes the following commands to be executed only
3925 if the expression is zero.
3927 * Fortran source language mode
3929 GDB now includes partial support for Fortran 77. It will recognize
3930 Fortran programs and can evaluate a subset of Fortran expressions, but
3931 variables and functions may not be handled correctly. GDB will work
3932 with G77, but does not yet know much about symbols emitted by other
3935 * Better HPUX support
3937 Most debugging facilities now work on dynamic executables for HPPAs
3938 running hpux9 or later. You can attach to running dynamically linked
3939 processes, but by default the dynamic libraries will be read-only, so
3940 for instance you won't be able to put breakpoints in them. To change
3941 that behavior do the following before running the program:
3947 This will cause the libraries to be mapped private and read-write.
3948 To revert to the normal behavior, do this:
3954 You cannot set breakpoints or examine data in the library until after
3955 the library is loaded if the function/data symbols do not have
3958 GDB can now also read debug symbols produced by the HP C compiler on
3959 HPPAs (sorry, no C++, Fortran or 68k support).
3961 * Target byte order now dynamically selectable
3963 You can choose which byte order to use with a target system, via the
3964 commands "set endian big" and "set endian little", and you can see the
3965 current setting by using "show endian". You can also give the command
3966 "set endian auto", in which case GDB will use the byte order
3967 associated with the executable. Currently, only embedded MIPS
3968 configurations support dynamic selection of target byte order.
3970 * New DOS host serial code
3972 This version uses DPMI interrupts to handle buffered I/O, so you
3973 no longer need to run asynctsr when debugging boards connected to
3976 *** Changes in GDB-4.13:
3978 * New "complete" command
3980 This lists all the possible completions for the rest of the line, if it
3981 were to be given as a command itself. This is intended for use by emacs.
3983 * Trailing space optional in prompt
3985 "set prompt" no longer adds a space for you after the prompt you set. This
3986 allows you to set a prompt which ends in a space or one that does not.
3988 * Breakpoint hit counts
3990 "info break" now displays a count of the number of times the breakpoint
3991 has been hit. This is especially useful in conjunction with "ignore"; you
3992 can ignore a large number of breakpoint hits, look at the breakpoint info
3993 to see how many times the breakpoint was hit, then run again, ignoring one
3994 less than that number, and this will get you quickly to the last hit of
3997 * Ability to stop printing at NULL character
3999 "set print null-stop" will cause GDB to stop printing the characters of
4000 an array when the first NULL is encountered. This is useful when large
4001 arrays actually contain only short strings.
4003 * Shared library breakpoints
4005 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4006 breakpoints in shared libraries before the executable is run.
4008 * Hardware watchpoints
4010 There is a new hardware breakpoint for the watch command for sparclite
4011 targets. See gdb/sparclite/hw_breakpoint.note.
4013 Hardware watchpoints are also now supported under GNU/Linux.
4017 Annotations have been added. These are for use with graphical interfaces,
4018 and are still experimental. Currently only gdba.el uses these.
4020 * Improved Irix 5 support
4022 GDB now works properly with Irix 5.2.
4024 * Improved HPPA support
4026 GDB now works properly with the latest GCC and GAS.
4028 * New native configurations
4030 Sequent PTX4 i[34]86-sequent-ptx4
4031 HPPA running OSF/1 hppa*-*-osf*
4032 Atari TT running SVR4 m68*-*-sysv4*
4033 RS/6000 LynxOS rs6000-*-lynxos*
4037 OS/9000 i[34]86-*-os9k
4038 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4041 * Hitachi SH7000 and E7000-PC ICE support
4043 There is now support for communicating with the Hitachi E7000-PC ICE.
4044 This is available automatically when GDB is configured for the SH.
4048 As usual, a variety of small fixes and improvements, both generic
4049 and configuration-specific. See the ChangeLog for more detail.
4051 *** Changes in GDB-4.12:
4053 * Irix 5 is now supported
4057 GDB-4.12 on the HPPA has a number of changes which make it unable
4058 to debug the output from the currently released versions of GCC and
4059 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4060 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4061 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4064 *** Changes in GDB-4.11:
4066 * User visible changes:
4070 The "set remotedebug" option is now consistent between the mips remote
4071 target, remote targets using the gdb-specific protocol, UDI (AMD's
4072 debug protocol for the 29k) and the 88k bug monitor. It is now an
4073 integer specifying a debug level (normally 0 or 1, but 2 means more
4074 debugging info for the mips target).
4076 * DEC Alpha native support
4078 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4079 debug info, but GDB works fairly well with the DEC compiler and should
4080 work with a future GCC release. See the README file for a few
4081 Alpha-specific notes.
4083 * Preliminary thread implementation
4085 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4087 * LynxOS native and target support for 386
4089 This release has been hosted on LynxOS 2.2, and also can be configured
4090 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4093 * Improvements in C++ mangling/demangling.
4095 This release has much better g++ debugging, specifically in name
4096 mangling/demangling, virtual function calls, print virtual table,
4097 call methods, ...etc.
4099 *** Changes in GDB-4.10:
4101 * User visible changes:
4103 Remote debugging using the GDB-specific (`target remote') protocol now
4104 supports the `load' command. This is only useful if you have some
4105 other way of getting the stub to the target system, and you can put it
4106 somewhere in memory where it won't get clobbered by the download.
4108 Filename completion now works.
4110 When run under emacs mode, the "info line" command now causes the
4111 arrow to point to the line specified. Also, "info line" prints
4112 addresses in symbolic form (as well as hex).
4114 All vxworks based targets now support a user settable option, called
4115 vxworks-timeout. This option represents the number of seconds gdb
4116 should wait for responses to rpc's. You might want to use this if
4117 your vxworks target is, perhaps, a slow software simulator or happens
4118 to be on the far side of a thin network line.
4122 This release contains support for using a DEC alpha as a GDB host for
4123 cross debugging. Native alpha debugging is not supported yet.
4126 *** Changes in GDB-4.9:
4130 This is the first GDB release which is accompanied by a matching testsuite.
4131 The testsuite requires installation of dejagnu, which should be available
4132 via ftp from most sites that carry GNU software.
4136 'Cfront' style demangling has had its name changed to 'ARM' style, to
4137 emphasize that it was written from the specifications in the C++ Annotated
4138 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4139 disclaimers, it still generated too much confusion with users attempting to
4140 use gdb with AT&T cfront.
4144 GDB now uses a standard remote interface to a simulator library.
4145 So far, the library contains simulators for the Zilog Z8001/2, the
4146 Hitachi H8/300, H8/500 and Super-H.
4148 * New targets supported
4150 H8/300 simulator h8300-hitachi-hms or h8300hms
4151 H8/500 simulator h8500-hitachi-hms or h8500hms
4152 SH simulator sh-hitachi-hms or sh
4153 Z8000 simulator z8k-zilog-none or z8ksim
4154 IDT MIPS board over serial line mips-idt-ecoff
4156 Cross-debugging to GO32 targets is supported. It requires a custom
4157 version of the i386-stub.c module which is integrated with the
4158 GO32 memory extender.
4160 * New remote protocols
4162 MIPS remote debugging protocol.
4164 * New source languages supported
4166 This version includes preliminary support for Chill, a Pascal like language
4167 used by telecommunications companies. Chill support is also being integrated
4168 into the GNU compiler, but we don't know when it will be publically available.
4171 *** Changes in GDB-4.8:
4173 * HP Precision Architecture supported
4175 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4176 version of this support was available as a set of patches from the
4177 University of Utah. GDB does not support debugging of programs
4178 compiled with the HP compiler, because HP will not document their file
4179 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4180 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4182 Many problems in the preliminary version have been fixed.
4184 * Faster and better demangling
4186 We have improved template demangling and fixed numerous bugs in the GNU style
4187 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4188 character types (wchar_t) are now supported. Demangling of each symbol is now
4189 only done once, and is cached when the symbol table for a file is read in.
4190 This results in a small increase in memory usage for C programs, a moderate
4191 increase in memory usage for C++ programs, and a fantastic speedup in
4194 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4195 from the specifications in the Annotated Reference Manual, which AT&T's
4196 compiler does not actually implement.
4198 * G++ multiple inheritance compiler problem
4200 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4201 inheritance lattices was reworked to properly discover ambiguities. We
4202 recently found an example which causes this new algorithm to fail in a
4203 very subtle way, producing bad debug information for those classes.
4204 The file 'gcc.patch' (in this directory) can be applied to gcc to
4205 circumvent the problem. A future GCC release will contain a complete
4208 The previous G++ debug info problem (mentioned below for the gdb-4.7
4209 release) is fixed in gcc version 2.3.2.
4211 * Improved configure script
4213 The `configure' script will now attempt to guess your system type if
4214 you don't supply a host system type. The old scheme of supplying a
4215 host system triplet is preferable over using this. All the magic is
4216 done in the new `config.guess' script. Examine it for details.
4218 We have also brought our configure script much more in line with the FSF's
4219 version. It now supports the --with-xxx options. In particular,
4220 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4221 The resulting GDB will not be able to read arbitrary object file formats --
4222 only the format ``expected'' to be used on the configured target system.
4223 We hope to make this the default in a future release.
4225 * Documentation improvements
4227 There's new internal documentation on how to modify GDB, and how to
4228 produce clean changes to the code. We implore people to read it
4229 before submitting changes.
4231 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4232 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4233 `info' files are also provided. To build `info' files from scratch,
4234 you will need the latest `makeinfo' release, which will be available in
4235 a future texinfo-X.Y release.
4237 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4238 We're not sure exactly which versions have this problem, but it has
4239 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4240 or better. If that isn't possible, there is a patch in
4241 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4242 around this problem.
4246 GDB now supports array constants that can be used in expressions typed in by
4247 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4248 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4251 The new directory `gdb/sparclite' contains a program that demonstrates
4252 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4254 * New native hosts supported
4256 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4257 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4259 * New targets supported
4261 AMD 29k family via UDI a29k-amd-udi or udi29k
4263 * New file formats supported
4265 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4266 HPUX core files, and SCO 3.2v2 core files.
4270 Attaching to processes now works again; thanks for the many bug reports.
4272 We have also stomped on a bunch of core dumps caused by
4273 printf_filtered("%s") problems.
4275 We eliminated a copyright problem on the rpc and ptrace header files
4276 for VxWorks, which was discovered at the last minute during the 4.7
4277 release. You should now be able to build a VxWorks GDB.
4279 You can now interrupt gdb while an attached process is running. This
4280 will cause the attached process to stop, and give control back to GDB.
4282 We fixed problems caused by using too many file descriptors
4283 for reading symbols from object files and libraries. This was
4284 especially a problem for programs that used many (~100) shared
4287 The `step' command now only enters a subroutine if there is line number
4288 information for the subroutine. Otherwise it acts like the `next'
4289 command. Previously, `step' would enter subroutines if there was
4290 any debugging information about the routine. This avoids problems
4291 when using `cc -g1' on MIPS machines.
4293 * Internal improvements
4295 GDB's internal interfaces have been improved to make it easier to support
4296 debugging of multiple languages in the future.
4298 GDB now uses a common structure for symbol information internally.
4299 Minimal symbols (derived from linkage symbols in object files), partial
4300 symbols (from a quick scan of debug information), and full symbols
4301 contain a common subset of information, making it easier to write
4302 shared code that handles any of them.
4304 * New command line options
4306 We now accept --silent as an alias for --quiet.
4310 The memory-mapped-malloc library is now licensed under the GNU Library
4311 General Public License.
4313 *** Changes in GDB-4.7:
4315 * Host/native/target split
4317 GDB has had some major internal surgery to untangle the support for
4318 hosts and remote targets. Now, when you configure GDB for a remote
4319 target, it will no longer load in all of the support for debugging
4320 local programs on the host. When fully completed and tested, this will
4321 ensure that arbitrary host/target combinations are possible.
4323 The primary conceptual shift is to separate the non-portable code in
4324 GDB into three categories. Host specific code is required any time GDB
4325 is compiled on that host, regardless of the target. Target specific
4326 code relates to the peculiarities of the target, but can be compiled on
4327 any host. Native specific code is everything else: it can only be
4328 built when the host and target are the same system. Child process
4329 handling and core file support are two common `native' examples.
4331 GDB's use of /proc for controlling Unix child processes is now cleaner.
4332 It has been split out into a single module under the `target_ops' vector,
4333 plus two native-dependent functions for each system that uses /proc.
4335 * New hosts supported
4337 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4338 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4339 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4341 * New targets supported
4343 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4344 68030 and CPU32 m68030-*-*, m68332-*-*
4346 * New native hosts supported
4348 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4349 (386bsd is not well tested yet)
4350 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4352 * New file formats supported
4354 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4355 supports reading of `a.out.adobe' object files, which are an a.out
4356 format extended with minimal information about multiple sections.
4360 `show copying' is the same as the old `info copying'.
4361 `show warranty' is the same as `info warrantee'.
4362 These were renamed for consistency. The old commands continue to work.
4364 `info handle' is a new alias for `info signals'.
4366 You can now define pre-command hooks, which attach arbitrary command
4367 scripts to any command. The commands in the hook will be executed
4368 prior to the user's command. You can also create a hook which will be
4369 executed whenever the program stops. See gdb.texinfo.
4373 We now deal with Cfront style name mangling, and can even extract type
4374 info from mangled symbols. GDB can automatically figure out which
4375 symbol mangling style your C++ compiler uses.
4377 Calling of methods and virtual functions has been improved as well.
4381 The crash that occured when debugging Sun Ansi-C compiled binaries is
4382 fixed. This was due to mishandling of the extra N_SO stabs output
4385 We also finally got Ultrix 4.2 running in house, and fixed core file
4386 support, with help from a dozen people on the net.
4388 John M. Farrell discovered that the reason that single-stepping was so
4389 slow on all of the Mips based platforms (primarily SGI and DEC) was
4390 that we were trying to demangle and lookup a symbol used for internal
4391 purposes on every instruction that was being stepped through. Changing
4392 the name of that symbol so that it couldn't be mistaken for a C++
4393 mangled symbol sped things up a great deal.
4395 Rich Pixley sped up symbol lookups in general by getting much smarter
4396 about when C++ symbol mangling is necessary. This should make symbol
4397 completion (TAB on the command line) much faster. It's not as fast as
4398 we'd like, but it's significantly faster than gdb-4.6.
4402 A new user controllable variable 'call_scratch_address' can
4403 specify the location of a scratch area to be used when GDB
4404 calls a function in the target. This is necessary because the
4405 usual method of putting the scratch area on the stack does not work
4406 in systems that have separate instruction and data spaces.
4408 We integrated changes to support the 29k UDI (Universal Debugger
4409 Interface), but discovered at the last minute that we didn't have all
4410 of the appropriate copyright paperwork. We are working with AMD to
4411 resolve this, and hope to have it available soon.
4415 We have sped up the remote serial line protocol, especially for targets
4416 with lots of registers. It now supports a new `expedited status' ('T')
4417 message which can be used in place of the existing 'S' status message.
4418 This allows the remote stub to send only the registers that GDB
4419 needs to make a quick decision about single-stepping or conditional
4420 breakpoints, eliminating the need to fetch the entire register set for
4421 each instruction being stepped through.
4423 The GDB remote serial protocol now implements a write-through cache for
4424 registers, only re-reading the registers if the target has run.
4426 There is also a new remote serial stub for SPARC processors. You can
4427 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4428 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4429 processor with a serial port.
4433 Configure.in files have become much easier to read and modify. A new
4434 `table driven' format makes it more obvious what configurations are
4435 supported, and what files each one uses.
4439 There is a new opcodes library which will eventually contain all of the
4440 disassembly routines and opcode tables. At present, it only contains
4441 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4442 disassembler (binutils/objdump) to share these routines.
4444 The libiberty library is now copylefted under the GNU Library General
4445 Public License. This allows more liberal use, and was done so libg++
4446 can use it. This makes no difference to GDB, since the Library License
4447 grants all the rights from the General Public License.
4451 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4452 reference to the stabs symbol info used by the debugger. It is (as far
4453 as we know) the only published document on this fascinating topic. We
4454 encourage you to read it, compare it to the stabs information on your
4455 system, and send improvements on the document in general (to
4456 bug-gdb@prep.ai.mit.edu).
4458 And, of course, many bugs have been fixed.
4461 *** Changes in GDB-4.6:
4463 * Better support for C++ function names
4465 GDB now accepts as input the "demangled form" of C++ overloaded function
4466 names and member function names, and can do command completion on such names
4467 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4468 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4469 Make use of command completion, it is your friend.
4471 GDB also now accepts a variety of C++ mangled symbol formats. They are
4472 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4473 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4474 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4475 for the list of formats.
4477 * G++ symbol mangling problem
4479 Recent versions of gcc have a bug in how they emit debugging information for
4480 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4481 directory) can be applied to gcc to fix the problem. Alternatively, if you
4482 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4483 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4484 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4487 * New 'maintenance' command
4489 All of the commands related to hacking GDB internals have been moved out of
4490 the main command set, and now live behind the 'maintenance' command. This
4491 can also be abbreviated as 'mt'. The following changes were made:
4493 dump-me -> maintenance dump-me
4494 info all-breakpoints -> maintenance info breakpoints
4495 printmsyms -> maintenance print msyms
4496 printobjfiles -> maintenance print objfiles
4497 printpsyms -> maintenance print psymbols
4498 printsyms -> maintenance print symbols
4500 The following commands are new:
4502 maintenance demangle Call internal GDB demangler routine to
4503 demangle a C++ link name and prints the result.
4504 maintenance print type Print a type chain for a given symbol
4506 * Change to .gdbinit file processing
4508 We now read the $HOME/.gdbinit file before processing the argv arguments
4509 (e.g. reading symbol files or core files). This allows global parameters to
4510 be set, which will apply during the symbol reading. The ./.gdbinit is still
4511 read after argv processing.
4513 * New hosts supported
4515 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4517 GNU/Linux support i386-unknown-linux or linux
4519 We are also including code to support the HP/PA running BSD and HPUX. This
4520 is almost guaranteed not to work, as we didn't have time to test or build it
4521 for this release. We are including it so that the more adventurous (or
4522 masochistic) of you can play with it. We also had major problems with the
4523 fact that the compiler that we got from HP doesn't support the -g option.
4526 * New targets supported
4528 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4530 * More smarts about finding #include files
4532 GDB now remembers the compilation directory for all include files, and for
4533 all files from which C is generated (like yacc and lex sources). This
4534 greatly improves GDB's ability to find yacc/lex sources, and include files,
4535 especially if you are debugging your program from a directory different from
4536 the one that contains your sources.
4538 We also fixed a bug which caused difficulty with listing and setting
4539 breakpoints in include files which contain C code. (In the past, you had to
4540 try twice in order to list an include file that you hadn't looked at before.)
4542 * Interesting infernals change
4544 GDB now deals with arbitrary numbers of sections, where the symbols for each
4545 section must be relocated relative to that section's landing place in the
4546 target's address space. This work was needed to support ELF with embedded
4547 stabs used by Solaris-2.0.
4549 * Bug fixes (of course!)
4551 There have been loads of fixes for the following things:
4552 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4553 i960, stabs, DOS(GO32), procfs, etc...
4555 See the ChangeLog for details.
4557 *** Changes in GDB-4.5:
4559 * New machines supported (host and target)
4561 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4563 SGI Irix-4.x mips-sgi-irix4 or iris4
4565 * New malloc package
4567 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4568 Mmalloc is capable of handling mutiple heaps of memory. It is also
4569 capable of saving a heap to a file, and then mapping it back in later.
4570 This can be used to greatly speedup the startup of GDB by using a
4571 pre-parsed symbol table which lives in a mmalloc managed heap. For
4572 more details, please read mmalloc/mmalloc.texi.
4576 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4577 'help info proc' for details.
4579 * MIPS ecoff symbol table format
4581 The code that reads MIPS symbol table format is now supported on all hosts.
4582 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4585 * File name changes for MS-DOS
4587 Many files in the config directories have been renamed to make it easier to
4588 support GDB on MS-DOSe systems (which have very restrictive file name
4589 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4590 environment) is close to working but has some remaining problems. Note
4591 that debugging of DOS programs is not supported, due to limitations
4592 in the ``operating system'', but it can be used to host cross-debugging.
4594 * Cross byte order fixes
4596 Many fixes have been made to support cross debugging of Sparc and MIPS
4597 targets from hosts whose byte order differs.
4599 * New -mapped and -readnow options
4601 If memory-mapped files are available on your system through the 'mmap'
4602 system call, you can use the -mapped option on the `file' or
4603 `symbol-file' commands to cause GDB to write the symbols from your
4604 program into a reusable file. If the program you are debugging is
4605 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4606 Future GDB debugging sessions will notice the presence of this file,
4607 and will quickly map in symbol information from it, rather than reading
4608 the symbol table from the executable program. Using the '-mapped'
4609 option in a GDB `file' or `symbol-file' command has the same effect as
4610 starting GDB with the '-mapped' command-line option.
4612 You can cause GDB to read the entire symbol table immediately by using
4613 the '-readnow' option with any of the commands that load symbol table
4614 information (or on the GDB command line). This makes the command
4615 slower, but makes future operations faster.
4617 The -mapped and -readnow options are typically combined in order to
4618 build a `fred.syms' file that contains complete symbol information.
4619 A simple GDB invocation to do nothing but build a `.syms' file for future
4622 gdb -batch -nx -mapped -readnow programname
4624 The `.syms' file is specific to the host machine on which GDB is run.
4625 It holds an exact image of GDB's internal symbol table. It cannot be
4626 shared across multiple host platforms.
4628 * longjmp() handling
4630 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4631 siglongjmp() without losing control. This feature has not yet been ported to
4632 all systems. It currently works on many 386 platforms, all MIPS-based
4633 platforms (SGI, DECstation, etc), and Sun3/4.
4637 Preliminary work has been put in to support the new Solaris OS from Sun. At
4638 this time, it can control and debug processes, but it is not capable of
4643 As always, many many bug fixes. The major areas were with g++, and mipsread.
4644 People using the MIPS-based platforms should experience fewer mysterious
4645 crashes and trashed symbol tables.
4647 *** Changes in GDB-4.4:
4649 * New machines supported (host and target)
4651 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4653 BSD Reno on Vax vax-dec-bsd
4654 Ultrix on Vax vax-dec-ultrix
4656 * New machines supported (target)
4658 AMD 29000 embedded, using EBMON a29k-none-none
4662 GDB continues to improve its handling of C++. `References' work better.
4663 The demangler has also been improved, and now deals with symbols mangled as
4664 per the Annotated C++ Reference Guide.
4666 GDB also now handles `stabs' symbol information embedded in MIPS
4667 `ecoff' symbol tables. Since the ecoff format was not easily
4668 extensible to handle new languages such as C++, this appeared to be a
4669 good way to put C++ debugging info into MIPS binaries. This option
4670 will be supported in the GNU C compiler, version 2, when it is
4673 * New features for SVR4
4675 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4676 shared libraries. Debugging dynamically linked programs should present
4677 only minor differences from debugging statically linked programs.
4679 The `info proc' command will print out information about any process
4680 on an SVR4 system (including the one you are debugging). At the moment,
4681 it prints the address mappings of the process.
4683 If you bring up GDB on another SVR4 system, please send mail to
4684 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4686 * Better dynamic linking support in SunOS
4688 Reading symbols from shared libraries which contain debugging symbols
4689 now works properly. However, there remain issues such as automatic
4690 skipping of `transfer vector' code during function calls, which
4691 make it harder to debug code in a shared library, than to debug the
4692 same code linked statically.
4696 GDB is now using the latest `getopt' routines from the FSF. This
4697 version accepts the -- prefix for options with long names. GDB will
4698 continue to accept the old forms (-option and +option) as well.
4699 Various single letter abbreviations for options have been explicity
4700 added to the option table so that they won't get overshadowed in the
4701 future by other options that begin with the same letter.
4705 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4706 Many assorted bugs have been handled. Many more remain to be handled.
4707 See the various ChangeLog files (primarily in gdb and bfd) for details.
4710 *** Changes in GDB-4.3:
4712 * New machines supported (host and target)
4714 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4715 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4716 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4718 * Almost SCO Unix support
4720 We had hoped to support:
4721 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4722 (except for core file support), but we discovered very late in the release
4723 that it has problems with process groups that render gdb unusable. Sorry
4724 about that. I encourage people to fix it and post the fixes.
4726 * Preliminary ELF and DWARF support
4728 GDB can read ELF object files on System V Release 4, and can handle
4729 debugging records for C, in DWARF format, in ELF files. This support
4730 is preliminary. If you bring up GDB on another SVR4 system, please
4731 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4736 GDB now uses the latest `readline' library. One user-visible change
4737 is that two tabs will list possible command completions, which previously
4738 required typing M-? (meta-question mark, or ESC ?).
4742 The `stepi' bug that many of you noticed has been squashed.
4743 Many bugs in C++ have been handled. Many more remain to be handled.
4744 See the various ChangeLog files (primarily in gdb and bfd) for details.
4746 * State of the MIPS world (in case you wondered):
4748 GDB can understand the symbol tables emitted by the compilers
4749 supplied by most vendors of MIPS-based machines, including DEC. These
4750 symbol tables are in a format that essentially nobody else uses.
4752 Some versions of gcc come with an assembler post-processor called
4753 mips-tfile. This program is required if you want to do source-level
4754 debugging of gcc-compiled programs. I believe FSF does not ship
4755 mips-tfile with gcc version 1, but it will eventually come with gcc
4758 Debugging of g++ output remains a problem. g++ version 1.xx does not
4759 really support it at all. (If you're lucky, you should be able to get
4760 line numbers and stack traces to work, but no parameters or local
4761 variables.) With some work it should be possible to improve the
4764 When gcc version 2 is released, you will have somewhat better luck.
4765 However, even then you will get confusing results for inheritance and
4768 We will eventually provide full debugging of g++ output on
4769 DECstations. This will probably involve some kind of stabs-in-ecoff
4770 encapulation, but the details have not been worked out yet.
4773 *** Changes in GDB-4.2:
4775 * Improved configuration
4777 Only one copy of `configure' exists now, and it is not self-modifying.
4778 Porting BFD is simpler.
4782 The `step' and `next' commands now only stop at the first instruction
4783 of a source line. This prevents the multiple stops that used to occur
4784 in switch statements, for-loops, etc. `Step' continues to stop if a
4785 function that has debugging information is called within the line.
4789 Lots of small bugs fixed. More remain.
4791 * New host supported (not target)
4793 Intel 386 PC clone running Mach i386-none-mach
4796 *** Changes in GDB-4.1:
4798 * Multiple source language support
4800 GDB now has internal scaffolding to handle several source languages.
4801 It determines the type of each source file from its filename extension,
4802 and will switch expression parsing and number formatting to match the
4803 language of the function in the currently selected stack frame.
4804 You can also specifically set the language to be used, with
4805 `set language c' or `set language modula-2'.
4809 GDB now has preliminary support for the GNU Modula-2 compiler,
4810 currently under development at the State University of New York at
4811 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4812 continue through the fall of 1991 and into 1992.
4814 Other Modula-2 compilers are currently not supported, and attempting to
4815 debug programs compiled with them will likely result in an error as the
4816 symbol table is read. Feel free to work on it, though!
4818 There are hooks in GDB for strict type checking and range checking,
4819 in the `Modula-2 philosophy', but they do not currently work.
4823 GDB can now write to executable and core files (e.g. patch
4824 a variable's value). You must turn this switch on, specify
4825 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4826 by assigning a new value to a variable. Modifications take
4829 * Automatic SunOS shared library reading
4831 When you run your program, GDB automatically determines where its
4832 shared libraries (if any) have been loaded, and reads their symbols.
4833 The `share' command is no longer needed. This also works when
4834 examining core files.
4838 You can specify the number of lines that the `list' command shows.
4841 * New machines supported (host and target)
4843 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4844 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4845 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4847 * New hosts supported (not targets)
4849 IBM RT/PC: romp-ibm-aix or rtpc
4851 * New targets supported (not hosts)
4853 AMD 29000 embedded with COFF a29k-none-coff
4854 AMD 29000 embedded with a.out a29k-none-aout
4855 Ultracomputer remote kernel debug a29k-nyu-kern
4857 * New remote interfaces
4863 *** Changes in GDB-4.0:
4867 Wide output is wrapped at good places to make the output more readable.
4869 Gdb now supports cross-debugging from a host machine of one type to a
4870 target machine of another type. Communication with the target system
4871 is over serial lines. The ``target'' command handles connecting to the
4872 remote system; the ``load'' command will download a program into the
4873 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4874 also supports debugging of realtime processes running under VxWorks,
4875 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4876 stub on the target system.
4878 New CPUs supported include the AMD 29000 and Intel 960.
4880 GDB now reads object files and symbol tables via a ``binary file''
4881 library, which allows a single copy of GDB to debug programs of multiple
4882 object file types such as a.out and coff.
4884 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4885 refcard.dvi and refcard.ps are available to format it).
4888 * Control-Variable user interface simplified
4890 All variables that control the operation of the debugger can be set
4891 by the ``set'' command, and displayed by the ``show'' command.
4893 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4894 ``Show prompt'' produces the response:
4895 Gdb's prompt is new-gdb=>.
4897 What follows are the NEW set commands. The command ``help set'' will
4898 print a complete list of old and new set commands. ``help set FOO''
4899 will give a longer description of the variable FOO. ``show'' will show
4900 all of the variable descriptions and their current settings.
4902 confirm on/off: Enables warning questions for operations that are
4903 hard to recover from, e.g. rerunning the program while
4904 it is already running. Default is ON.
4906 editing on/off: Enables EMACS style command line editing
4907 of input. Previous lines can be recalled with
4908 control-P, the current line can be edited with control-B,
4909 you can search for commands with control-R, etc.
4912 history filename NAME: NAME is where the gdb command history
4913 will be stored. The default is .gdb_history,
4914 or the value of the environment variable
4917 history size N: The size, in commands, of the command history. The
4918 default is 256, or the value of the environment variable
4921 history save on/off: If this value is set to ON, the history file will
4922 be saved after exiting gdb. If set to OFF, the
4923 file will not be saved. The default is OFF.
4925 history expansion on/off: If this value is set to ON, then csh-like
4926 history expansion will be performed on
4927 command line input. The default is OFF.
4929 radix N: Sets the default radix for input and output. It can be set
4930 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4931 in the current radix, so "set radix 10" is always a no-op.
4933 height N: This integer value is the number of lines on a page. Default
4934 is 24, the current `stty rows'' setting, or the ``li#''
4935 setting from the termcap entry matching the environment
4938 width N: This integer value is the number of characters on a line.
4939 Default is 80, the current `stty cols'' setting, or the ``co#''
4940 setting from the termcap entry matching the environment
4943 Note: ``set screensize'' is obsolete. Use ``set height'' and
4944 ``set width'' instead.
4946 print address on/off: Print memory addresses in various command displays,
4947 such as stack traces and structure values. Gdb looks
4948 more ``symbolic'' if you turn this off; it looks more
4949 ``machine level'' with it on. Default is ON.
4951 print array on/off: Prettyprint arrays. New convenient format! Default
4954 print demangle on/off: Print C++ symbols in "source" form if on,
4957 print asm-demangle on/off: Same, for assembler level printouts
4960 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4963 * Support for Epoch Environment.
4965 The epoch environment is a version of Emacs v18 with windowing. One
4966 new command, ``inspect'', is identical to ``print'', except that if you
4967 are running in the epoch environment, the value is printed in its own
4971 * Support for Shared Libraries
4973 GDB can now debug programs and core files that use SunOS shared libraries.
4974 Symbols from a shared library cannot be referenced
4975 before the shared library has been linked with the program (this
4976 happens after you type ``run'' and before the function main() is entered).
4977 At any time after this linking (including when examining core files
4978 from dynamically linked programs), gdb reads the symbols from each
4979 shared library when you type the ``sharedlibrary'' command.
4980 It can be abbreviated ``share''.
4982 sharedlibrary REGEXP: Load shared object library symbols for files
4983 matching a unix regular expression. No argument
4984 indicates to load symbols for all shared libraries.
4986 info sharedlibrary: Status of loaded shared libraries.
4991 A watchpoint stops execution of a program whenever the value of an
4992 expression changes. Checking for this slows down execution
4993 tremendously whenever you are in the scope of the expression, but is
4994 quite useful for catching tough ``bit-spreader'' or pointer misuse
4995 problems. Some machines such as the 386 have hardware for doing this
4996 more quickly, and future versions of gdb will use this hardware.
4998 watch EXP: Set a watchpoint (breakpoint) for an expression.
5000 info watchpoints: Information about your watchpoints.
5002 delete N: Deletes watchpoint number N (same as breakpoints).
5003 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5004 enable N: Re-enables watchpoint number N (same as breakpoints).
5007 * C++ multiple inheritance
5009 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5012 * C++ exception handling
5014 Gdb now supports limited C++ exception handling. Besides the existing
5015 ability to breakpoint on an exception handler, gdb can breakpoint on
5016 the raising of an exception (before the stack is peeled back to the
5019 catch FOO: If there is a FOO exception handler in the dynamic scope,
5020 set a breakpoint to catch exceptions which may be raised there.
5021 Multiple exceptions (``catch foo bar baz'') may be caught.
5023 info catch: Lists all exceptions which may be caught in the
5024 current stack frame.
5027 * Minor command changes
5029 The command ``call func (arg, arg, ...)'' now acts like the print
5030 command, except it does not print or save a value if the function's result
5031 is void. This is similar to dbx usage.
5033 The ``up'' and ``down'' commands now always print the frame they end up
5034 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5035 frames without printing.
5037 * New directory command
5039 'dir' now adds directories to the FRONT of the source search path.
5040 The path starts off empty. Source files that contain debug information
5041 about the directory in which they were compiled can be found even
5042 with an empty path; Sun CC and GCC include this information. If GDB can't
5043 find your source file in the current directory, type "dir .".
5045 * Configuring GDB for compilation
5047 For normal use, type ``./configure host''. See README or gdb.texinfo
5050 GDB now handles cross debugging. If you are remotely debugging between
5051 two different machines, type ``./configure host -target=targ''.
5052 Host is the machine where GDB will run; targ is the machine
5053 where the program that you are debugging will run.