1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
6 * GDB now supports debugging microMIPS binaries.
8 * The "info os" command on GNU/Linux can now display information on
9 several new classes of objects managed by the operating system:
10 "info os procgroups" lists process groups
11 "info os files" lists file descriptors
12 "info os sockets" lists internet-domain sockets
13 "info os shm" lists shared-memory regions
14 "info os semaphores" lists semaphores
15 "info os msg" lists message queues
16 "info os modules" lists loaded kernel modules
18 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
19 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
20 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
21 options and inspect the probe arguments using the new $_probe_arg family
22 of convenience variables. You can obtain more information about SystemTap
23 in <http://sourceware.org/systemtap/>.
25 * GDB now supports reversible debugging on ARM, it allows you to
26 debug basic ARM and THUMB instructions, and provides
27 record/replay support.
29 * The option "symbol-reloading" has been deleted as it is no longer used.
33 ** GDB commands implemented in Python can now be put in command class
36 ** The "maint set python print-stack on|off" is now deleted.
38 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
39 apply "flag enum"-style pretty-printing to any enum.
41 ** gdb.lookup_symbol can now work when there is no current frame.
43 ** gdb.Symbol now has a 'line' attribute, holding the line number in
44 the source at which the symbol was defined.
46 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
47 method 'value'. The former indicates whether the symbol needs a
48 frame in order to compute its value, and the latter computes the
51 ** A new method 'referenced_value' on gdb.Value objects which can
52 dereference pointer as well as C++ reference values.
54 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
55 which return the global and static blocks (as gdb.Block objects),
56 of the underlying symbol table, respectively.
58 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
59 object associated with a PC value.
61 * Go language support.
62 GDB now supports debugging programs written in the Go programming
65 * GDBserver now supports stdio connections.
66 E.g. (gdb) target remote | ssh myhost gdbserver - hello
68 * The binary "gdbtui" can no longer be built or installed.
69 Use "gdb -tui" instead.
71 * GDB will now print "flag" enums specially. A flag enum is one where
72 all the enumerator values have no bits in common when pairwise
73 "and"ed. When printing a value whose type is a flag enum, GDB will
74 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
75 (gdb) print (enum E) 3
78 * The filename part of a linespec will now match trailing components
79 of a source file name. For example, "break gcc/expr.c:1000" will
80 now set a breakpoint in build/gcc/expr.c, but not
83 * The "info proc" and "generate-core-file" commands will now also
84 work on remote targets connected to GDBserver on Linux.
86 * The command "info catch" has been removed. It has been disabled
89 * The "catch exception" and "catch assert" commands now accept
90 a condition at the end of the command, much like the "break"
91 command does. For instance:
93 (gdb) catch exception Constraint_Error if Barrier = True
95 Previously, it was possible to add a condition to such catchpoints,
96 but it had to be done as a second step, after the catchpoint had been
97 created, using the "condition" command.
99 * The "info static-tracepoint-marker" command will now also work on
100 native Linux targets with in-process agent.
102 * GDB can now set breakpoints on inlined functions.
104 * The .gdb_index section has been updated to include symbols for
105 inlined functions. GDB will ignore older .gdb_index sections by
106 default, which could cause symbol files to be loaded more slowly
107 until their .gdb_index sections can be recreated. The new option
108 --use-deprecated-index-sections will cause GDB to use any older
109 .gdb_index sections it finds. This will restore performance, but
110 the ability to set breakpoints on inlined functions will be lost
111 in symbol files with older .gdb_index sections.
113 * Ada support for GDB/MI Variable Objects has been added.
115 * GDB can now support 'breakpoint always-inserted mode' in 'record'
120 ** "catch load" and "catch unload" can be used to stop when a shared
121 library is loaded or unloaded, respectively.
123 ** "enable count" can be used to auto-disable a breakpoint after
126 ** "info vtbl" can be used to show the virtual method tables for
127 C++ and Java objects.
129 ** "explore" and its sub commands "explore value" and "explore type"
130 can be used to reccursively explore values and types of
131 expressions. These commands are available only if GDB is
132 configured with '--with-python'.
134 ** "info auto-load" shows status of all kinds of auto-loaded files,
135 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
136 sequences of commands files, "info auto-load python-scripts"
137 shows status of auto-loading Python script files,
138 "info auto-load local-gdbinit" shows status of loading init file
139 (.gdbinit) from current directory and "info auto-load libthread-db" shows
140 status of inferior specific thread debugging shared library loading.
142 ** "info auto-load-scripts", "set auto-load-scripts on|off"
143 and "show auto-load-scripts" commands have been deprecated, use their
144 "info auto-load python-scripts", "set auto-load python-scripts on|off"
145 and "show auto-load python-scripts" counterparts instead.
147 ** "dprintf location,format,args..." creates a dynamic printf, which
148 is basically a breakpoint that does a printf and immediately
149 resumes your program's execution, so it is like a printf that you
150 can insert dynamically at runtime instead of at compiletime.
152 ** "set print symbol"
154 Controls whether GDB attempts to display the symbol, if any,
155 corresponding to addresses it prints. This defaults to "on", but
156 you can set it to "off" to restore GDB's previous behavior.
160 Renesas RL78 rl78-*-elf
161 HP OpenVMS ia64 ia64-hp-openvms*
163 * GDBserver supports evaluation of breakpoint conditions. When
164 support is advertised by GDBserver, GDB may be told to send the
165 breakpoint conditions in bytecode form to GDBserver. GDBserver
166 will only report the breakpoint trigger to GDB when its condition
172 show mips compression
173 Select the compressed ISA encoding used in functions that have no symbol
174 information available. The encoding can be set to either of:
177 and is updated automatically from ELF file flags if available.
179 set breakpoint condition-evaluation
180 show breakpoint condition-evaluation
181 Control whether breakpoint conditions are evaluated by GDB ("host") or by
182 GDBserver ("target"). Default option "auto" chooses the most efficient
184 This option can improve debugger efficiency depending on the speed of the
188 Disable auto-loading globally.
191 Show auto-loading setting of all kinds of auto-loaded files.
193 set auto-load gdb-scripts on|off
194 show auto-load gdb-scripts
195 Control auto-loading of GDB canned sequences of commands files.
197 set auto-load python-scripts on|off
198 show auto-load python-scripts
199 Control auto-loading of Python script files.
201 set auto-load local-gdbinit on|off
202 show auto-load local-gdbinit
203 Control loading of init file (.gdbinit) from current directory.
205 set auto-load libthread-db on|off
206 show auto-load libthread-db
207 Control auto-loading of inferior specific thread debugging shared library.
209 set auto-load scripts-directory <dir1>[:<dir2>...]
210 show auto-load scripts-directory
211 Set a list of directories from which to load auto-loaded scripts.
212 Automatically loaded Python scripts and GDB scripts are located in one
213 of the directories listed by this option.
214 The delimiter (':' above) may differ according to the host platform.
216 set auto-load safe-path <dir1>[:<dir2>...]
217 show auto-load safe-path
218 Set a list of directories from which it is safe to auto-load files.
219 The delimiter (':' above) may differ according to the host platform.
221 set debug auto-load on|off
223 Control display of debugging info for auto-loading the files above.
225 set dprintf-style gdb|call
227 Control the way in which a dynamic printf is performed; "gdb" requests
228 a GDB printf command, while "call" causes dprintf to call a function
231 set dprintf-function <expr>
232 show dprintf-function
233 set dprintf-channel <expr>
235 Set the function and optional first argument to the call when using
236 the "call" style of dynamic printf.
238 * New configure options
241 Configure default value for the 'set auto-load scripts-directory'
242 setting above. It defaults to '$datadir/auto-load', $datadir
243 representing GDB's data directory (available via show data-directory).
245 --with-auto-load-safe-path
246 Configure default value for the 'set auto-load safe-path' setting
247 above. It defaults to the --with-auto-load-dir setting.
249 --without-auto-load-safe-path
250 Set 'set auto-load safe-path' to '/', effectively disabling this
255 z0/z1 conditional breakpoints extension
257 The z0/z1 breakpoint insertion packets have been extended to carry
258 a list of conditional expressions over to the remote stub depending on the
259 condition evaluation mode. The use of this extension can be controlled
260 via the "set remote conditional-breakpoints-packet" command.
264 Specify the signals which the remote stub may pass to the debugged
265 program without GDB involvement.
267 * New command line options
269 --init-command=FILE, -ix Like --command, -x but execute it
270 before loading inferior.
271 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
272 execute it before loading inferior.
274 *** Changes in GDB 7.4
276 * GDB now handles ambiguous linespecs more consistently; the existing
277 FILE:LINE support has been expanded to other types of linespecs. A
278 breakpoint will now be set on all matching locations in all
279 inferiors, and locations will be added or removed according to
282 * GDB now allows you to skip uninteresting functions and files when
283 stepping with the "skip function" and "skip file" commands.
285 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
286 and "show remote hardware-watchpoint-length-limit". These allows to
287 set or show the maximum length limit (in bytes) of a remote
288 target hardware watchpoint.
290 This allows e.g. to use "unlimited" hardware watchpoints with the
291 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
292 watchpoints are slower than real hardware watchpoints but are
293 significantly faster than gdb software watchpoints.
297 ** The register_pretty_printer function in module gdb.printing now takes
298 an optional `replace' argument. If True, the new printer replaces any
301 ** The "maint set python print-stack on|off" command has been
302 deprecated and will be deleted in GDB 7.5.
303 A new command: "set python print-stack none|full|message" has
304 replaced it. Additionally, the default for "print-stack" is
305 now "message", which just prints the error message without
308 ** A prompt substitution hook (prompt_hook) is now available to the
311 ** A new Python module, gdb.prompt has been added to the GDB Python
312 modules library. This module provides functionality for
313 escape sequences in prompts (used by set/show
314 extended-prompt). These escape sequences are replaced by their
317 ** Python commands and convenience-functions located in
318 'data-directory'/python/gdb/command and
319 'data-directory'/python/gdb/function are now automatically loaded
322 ** Blocks now provide four new attributes. global_block and
323 static_block will return the global and static blocks
324 respectively. is_static and is_global are boolean attributes
325 that indicate if the block is one of those two types.
327 ** Symbols now provide the "type" attribute, the type of the symbol.
329 ** The "gdb.breakpoint" function has been deprecated in favor of
332 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
333 of a function. This class is based on the "finish" command
334 available in the CLI.
336 ** Type objects for struct and union types now allow access to
337 the fields using standard Python dictionary (mapping) methods.
338 For example, "some_type['myfield']" now works, as does
341 ** A new event "gdb.new_objfile" has been added, triggered by loading a
344 ** A new function, "deep_items" has been added to the gdb.types
345 module in the GDB Python modules library. This function returns
346 an iterator over the fields of a struct or union type. Unlike
347 the standard Python "iteritems" method, it will recursively traverse
348 any anonymous fields.
352 ** "*stopped" events can report several new "reason"s, such as
355 ** Breakpoint changes are now notified using new async records, like
356 "=breakpoint-modified".
358 ** New command -ada-task-info.
360 * libthread-db-search-path now supports two special values: $sdir and $pdir.
361 $sdir specifies the default system locations of shared libraries.
362 $pdir specifies the directory where the libpthread used by the application
365 GDB no longer looks in $sdir and $pdir after it has searched the directories
366 mentioned in libthread-db-search-path. If you want to search those
367 directories, they must be specified in libthread-db-search-path.
368 The default value of libthread-db-search-path on GNU/Linux and Solaris
369 systems is now "$sdir:$pdir".
371 $pdir is not supported by gdbserver, it is currently ignored.
372 $sdir is supported by gdbserver.
374 * New configure option --with-iconv-bin.
375 When using the internationalization support like the one in the GNU C
376 library, GDB will invoke the "iconv" program to get a list of supported
377 character sets. If this program lives in a non-standard location, one can
378 use this option to specify where to find it.
380 * When natively debugging programs on PowerPC BookE processors running
381 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
382 watchpoints, which specify a mask in addition to an address to watch.
383 The mask specifies that some bits of an address (the bits which are
384 reset in the mask) should be ignored when matching the address accessed
385 by the inferior against the watchpoint address. See the "PowerPC Embedded"
386 section in the user manual for more details.
388 * The new option --once causes GDBserver to stop listening for connections once
389 the first connection is made. The listening port used by GDBserver will
390 become available after that.
392 * New commands "info macros" and "alias" have been added.
394 * New function parameters suffix @entry specifies value of function parameter
395 at the time the function got called. Entry values are available only since
401 "!" is now an alias of the "shell" command.
402 Note that no space is needed between "!" and SHELL COMMAND.
406 watch EXPRESSION mask MASK_VALUE
407 The watch command now supports the mask argument which allows creation
408 of masked watchpoints, if the current architecture supports this feature.
410 info auto-load-scripts [REGEXP]
411 This command was formerly named "maintenance print section-scripts".
412 It is now generally useful and is no longer a maintenance-only command.
414 info macro [-all] [--] MACRO
415 The info macro command has new options `-all' and `--'. The first for
416 printing all definitions of a macro. The second for explicitly specifying
417 the end of arguments and the beginning of the macro name in case the macro
418 name starts with a hyphen.
420 collect[/s] EXPRESSIONS
421 The tracepoint collect command now takes an optional modifier "/s"
422 that directs it to dereference pointer-to-character types and
423 collect the bytes of memory up to a zero byte. The behavior is
424 similar to what you see when you use the regular print command on a
425 string. An optional integer following the "/s" sets a bound on the
426 number of bytes that will be collected.
429 The trace start command now interprets any supplied arguments as a
430 note to be recorded with the trace run, with an effect similar to
431 setting the variable trace-notes.
434 The trace stop command now interprets any arguments as a note to be
435 mentioned along with the tstatus report that the trace was stopped
436 with a command. The effect is similar to setting the variable
439 * Tracepoints can now be enabled and disabled at any time after a trace
440 experiment has been started using the standard "enable" and "disable"
441 commands. It is now possible to start a trace experiment with no enabled
442 tracepoints; GDB will display a warning, but will allow the experiment to
443 begin, assuming that tracepoints will be enabled as needed while the trace
446 * Fast tracepoints on 32-bit x86-architectures can now be placed at
447 locations with 4-byte instructions, when they were previously
448 limited to locations with instructions of 5 bytes or longer.
454 Set the GDB prompt, and allow escape sequences to be inserted to
455 display miscellaneous information (see 'help set extended-prompt'
456 for the list of sequences). This prompt (and any information
457 accessed through the escape sequences) is updated every time the
460 set print entry-values (both|compact|default|if-needed|no|only|preferred)
461 show print entry-values
462 Set printing of frame argument values at function entry. In some cases
463 GDB can determine the value of function argument which was passed by the
464 function caller, even if the value was modified inside the called function.
466 set debug entry-values
467 show debug entry-values
468 Control display of debugging info for determining frame argument values at
469 function entry and virtual tail call frames.
471 set basenames-may-differ
472 show basenames-may-differ
473 Set whether a source file may have multiple base names.
474 (A "base name" is the name of a file with the directory part removed.
475 Example: The base name of "/home/user/hello.c" is "hello.c".)
476 If set, GDB will canonicalize file names (e.g., expand symlinks)
477 before comparing them. Canonicalization is an expensive operation,
478 but it allows the same file be known by more than one base name.
479 If not set (the default), all source files are assumed to have just
480 one base name, and gdb will do file name comparisons more efficiently.
486 Set a user name and notes for the current and any future trace runs.
487 This is useful for long-running and/or disconnected traces, to
488 inform others (or yourself) as to who is running the trace, supply
489 contact information, or otherwise explain what is going on.
492 show trace-stop-notes
493 Set a note attached to the trace run, that is displayed when the
494 trace has been stopped by a tstop command. This is useful for
495 instance as an explanation, if you are stopping a trace run that was
496 started by someone else.
502 Dynamically enable a tracepoint in a started trace experiment.
506 Dynamically disable a tracepoint in a started trace experiment.
510 Set the user and notes of the trace run.
514 Query the current status of a tracepoint.
518 Query the minimum length of instruction at which a fast tracepoint may
521 * Dcache size (number of lines) and line-size are now runtime-configurable
522 via "set dcache line" and "set dcache line-size" commands.
526 Texas Instruments TMS320C6x tic6x-*-*
530 Renesas RL78 rl78-*-elf
532 *** Changes in GDB 7.3.1
534 * The build failure for NetBSD and OpenBSD targets have now been fixed.
536 *** Changes in GDB 7.3
538 * GDB has a new command: "thread find [REGEXP]".
539 It finds the thread id whose name, target id, or thread extra info
540 matches the given regular expression.
542 * The "catch syscall" command now works on mips*-linux* targets.
544 * The -data-disassemble MI command now supports modes 2 and 3 for
545 dumping the instruction opcodes.
547 * New command line options
549 -data-directory DIR Specify DIR as the "data-directory".
550 This is mostly for testing purposes.
552 * The "maint set python auto-load on|off" command has been renamed to
553 "set auto-load-scripts on|off".
555 * GDB has a new command: "set directories".
556 It is like the "dir" command except that it replaces the
557 source path list instead of augmenting it.
559 * GDB now understands thread names.
561 On GNU/Linux, "info threads" will display the thread name as set by
562 prctl or pthread_setname_np.
564 There is also a new command, "thread name", which can be used to
565 assign a name internally for GDB to display.
568 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
569 has been integrated into GDB.
573 ** The function gdb.Write now accepts an optional keyword 'stream'.
574 This keyword, when provided, will direct the output to either
575 stdout, stderr, or GDB's logging output.
577 ** Parameters can now be be sub-classed in Python, and in particular
578 you may implement the get_set_doc and get_show_doc functions.
579 This improves how Parameter set/show documentation is processed
580 and allows for more dynamic content.
582 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
583 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
584 have an is_valid method.
586 ** Breakpoints can now be sub-classed in Python, and in particular
587 you may implement a 'stop' function that is executed each time
588 the inferior reaches that breakpoint.
590 ** New function gdb.lookup_global_symbol looks up a global symbol.
592 ** GDB values in Python are now callable if the value represents a
593 function. For example, if 'some_value' represents a function that
594 takes two integer parameters and returns a value, you can call
595 that function like so:
597 result = some_value (10,20)
599 ** Module gdb.types has been added.
600 It contains a collection of utilities for working with gdb.Types objects:
601 get_basic_type, has_field, make_enum_dict.
603 ** Module gdb.printing has been added.
604 It contains utilities for writing and registering pretty-printers.
605 New classes: PrettyPrinter, SubPrettyPrinter,
606 RegexpCollectionPrettyPrinter.
607 New function: register_pretty_printer.
609 ** New commands "info pretty-printers", "enable pretty-printer" and
610 "disable pretty-printer" have been added.
612 ** gdb.parameter("directories") is now available.
614 ** New function gdb.newest_frame returns the newest frame in the
617 ** The gdb.InferiorThread class has a new "name" attribute. This
618 holds the thread's name.
620 ** Python Support for Inferior events.
621 Python scripts can add observers to be notified of events
622 occurring in the process being debugged.
623 The following events are currently supported:
624 - gdb.events.cont Continue event.
625 - gdb.events.exited Inferior exited event.
626 - gdb.events.stop Signal received, and Breakpoint hit events.
630 ** GDB now puts template parameters in scope when debugging in an
631 instantiation. For example, if you have:
633 template<int X> int func (void) { return X; }
635 then if you step into func<5>, "print X" will show "5". This
636 feature requires proper debuginfo support from the compiler; it
637 was added to GCC 4.5.
639 ** The motion commands "next", "finish", "until", and "advance" now
640 work better when exceptions are thrown. In particular, GDB will
641 no longer lose control of the inferior; instead, the GDB will
642 stop the inferior at the point at which the exception is caught.
643 This functionality requires a change in the exception handling
644 code that was introduced in GCC 4.5.
646 * GDB now follows GCC's rules on accessing volatile objects when
647 reading or writing target state during expression evaluation.
648 One notable difference to prior behavior is that "print x = 0"
649 no longer generates a read of x; the value of the assignment is
650 now always taken directly from the value being assigned.
652 * GDB now has some support for using labels in the program's source in
653 linespecs. For instance, you can use "advance label" to continue
654 execution to a label.
656 * GDB now has support for reading and writing a new .gdb_index
657 section. This section holds a fast index of DWARF debugging
658 information and can be used to greatly speed up GDB startup and
659 operation. See the documentation for `save gdb-index' for details.
661 * The "watch" command now accepts an optional "-location" argument.
662 When used, this causes GDB to watch the memory referred to by the
663 expression. Such a watchpoint is never deleted due to it going out
666 * GDB now supports thread debugging of core dumps on GNU/Linux.
668 GDB now activates thread debugging using the libthread_db library
669 when debugging GNU/Linux core dumps, similarly to when debugging
670 live processes. As a result, when debugging a core dump file, GDB
671 is now able to display pthread_t ids of threads. For example, "info
672 threads" shows the same output as when debugging the process when it
673 was live. In earlier releases, you'd see something like this:
676 * 1 LWP 6780 main () at main.c:10
678 While now you see this:
681 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
683 It is also now possible to inspect TLS variables when debugging core
686 When debugging a core dump generated on a machine other than the one
687 used to run GDB, you may need to point GDB at the correct
688 libthread_db library with the "set libthread-db-search-path"
689 command. See the user manual for more details on this command.
691 * When natively debugging programs on PowerPC BookE processors running
692 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
693 which stop execution of the inferior whenever it executes an instruction
694 at any address within the specified range. See the "PowerPC Embedded"
695 section in the user manual for more details.
697 * New features in the GDB remote stub, GDBserver
699 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
700 and i686 LynxOS (version 5.x).
702 ** GDBserver is now supported on Blackfin Linux.
704 * New native configurations
706 ia64 HP-UX ia64-*-hpux*
710 Analog Devices, Inc. Blackfin Processor bfin-*
712 * Ada task switching is now supported on sparc-elf targets when
713 debugging a program using the Ravenscar Profile. For more information,
714 see the "Tasking Support when using the Ravenscar Profile" section
715 in the GDB user manual.
717 * Guile support was removed.
719 * New features in the GNU simulator
721 ** The --map-info flag lists all known core mappings.
723 ** CFI flashes may be simulated via the "cfi" device.
725 *** Changes in GDB 7.2
727 * Shared library support for remote targets by default
729 When GDB is configured for a generic, non-OS specific target, like
730 for example, --target=arm-eabi or one of the many *-*-elf targets,
731 GDB now queries remote stubs for loaded shared libraries using the
732 `qXfer:libraries:read' packet. Previously, shared library support
733 was always disabled for such configurations.
737 ** Argument Dependent Lookup (ADL)
739 In C++ ADL lookup directs function search to the namespaces of its
740 arguments even if the namespace has not been imported.
750 Here the compiler will search for `foo' in the namespace of 'b'
751 and find A::foo. GDB now supports this. This construct is commonly
752 used in the Standard Template Library for operators.
754 ** Improved User Defined Operator Support
756 In addition to member operators, GDB now supports lookup of operators
757 defined in a namespace and imported with a `using' directive, operators
758 defined in the global scope, operators imported implicitly from an
759 anonymous namespace, and the ADL operators mentioned in the previous
761 GDB now also supports proper overload resolution for all the previously
762 mentioned flavors of operators.
764 ** static const class members
766 Printing of static const class members that are initialized in the
767 class definition has been fixed.
769 * Windows Thread Information Block access.
771 On Windows targets, GDB now supports displaying the Windows Thread
772 Information Block (TIB) structure. This structure is visible either
773 by using the new command `info w32 thread-information-block' or, by
774 dereferencing the new convenience variable named `$_tlb', a
775 thread-specific pointer to the TIB. This feature is also supported
776 when remote debugging using GDBserver.
780 Static tracepoints are calls in the user program into a tracing
781 library. One such library is a port of the LTTng kernel tracer to
782 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
783 When debugging with GDBserver, GDB now supports combining the GDB
784 tracepoint machinery with such libraries. For example: the user can
785 use GDB to probe a static tracepoint marker (a call from the user
786 program into the tracing library) with the new "strace" command (see
787 "New commands" below). This creates a "static tracepoint" in the
788 breakpoint list, that can be manipulated with the same feature set
789 as fast and regular tracepoints. E.g., collect registers, local and
790 global variables, collect trace state variables, and define
791 tracepoint conditions. In addition, the user can collect extra
792 static tracepoint marker specific data, by collecting the new
793 $_sdata internal variable. When analyzing the trace buffer, you can
794 inspect $_sdata like any other variable available to GDB. For more
795 information, see the "Tracepoints" chapter in GDB user manual. New
796 remote packets have been defined to support static tracepoints, see
797 the "New remote packets" section below.
799 * Better reconstruction of tracepoints after disconnected tracing
801 GDB will attempt to download the original source form of tracepoint
802 definitions when starting a trace run, and then will upload these
803 upon reconnection to the target, resulting in a more accurate
804 reconstruction of the tracepoints that are in use on the target.
808 You can now exercise direct control over the ways that GDB can
809 affect your program. For instance, you can disallow the setting of
810 breakpoints, so that the program can run continuously (assuming
811 non-stop mode). In addition, the "observer" variable is available
812 to switch all of the different controls; in observer mode, GDB
813 cannot affect the target's behavior at all, which is useful for
814 tasks like diagnosing live systems in the field.
816 * The new convenience variable $_thread holds the number of the
823 Return the address of the Windows Thread Information Block of a given thread.
827 In response to several of the tracepoint packets, the target may now
828 also respond with a number of intermediate `qRelocInsn' request
829 packets before the final result packet, to have GDB handle
830 relocating an instruction to execute at a different address. This
831 is particularly useful for stubs that support fast tracepoints. GDB
832 reports support for this feature in the qSupported packet.
836 List static tracepoint markers in the target program.
840 List static tracepoint markers at a given address in the target
843 qXfer:statictrace:read
845 Read the static trace data collected (by a `collect $_sdata'
846 tracepoint action). The remote stub reports support for this packet
847 to gdb's qSupported query.
851 Send the current settings of GDB's permission flags.
855 Send part of the source (textual) form of a tracepoint definition,
856 which includes location, conditional, and action list.
858 * The source command now accepts a -s option to force searching for the
859 script in the source search path even if the script name specifies
862 * New features in the GDB remote stub, GDBserver
864 - GDBserver now support tracepoints (including fast tracepoints, and
865 static tracepoints). The feature is currently supported by the
866 i386-linux and amd64-linux builds. See the "Tracepoints support
867 in gdbserver" section in the manual for more information.
869 GDBserver JIT compiles the tracepoint's conditional agent
870 expression bytecode into native code whenever possible for low
871 overhead dynamic tracepoints conditionals. For such tracepoints,
872 an expression that examines program state is evaluated when the
873 tracepoint is reached, in order to determine whether to capture
874 trace data. If the condition is simple and false, processing the
875 tracepoint finishes very quickly and no data is gathered.
877 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
878 for static tracepoints support.
880 - GDBserver now supports x86_64 Windows 64-bit debugging.
882 * GDB now sends xmlRegisters= in qSupported packet to indicate that
883 it understands register description.
885 * The --batch flag now disables pagination and queries.
887 * X86 general purpose registers
889 GDB now supports reading/writing byte, word and double-word x86
890 general purpose registers directly. This means you can use, say,
891 $ah or $ax to refer, respectively, to the byte register AH and
892 16-bit word register AX that are actually portions of the 32-bit
893 register EAX or 64-bit register RAX.
895 * The `commands' command now accepts a range of breakpoints to modify.
896 A plain `commands' following a command that creates multiple
897 breakpoints affects all the breakpoints set by that command. This
898 applies to breakpoints set by `rbreak', and also applies when a
899 single `break' command creates multiple breakpoints (e.g.,
900 breakpoints on overloaded c++ functions).
902 * The `rbreak' command now accepts a filename specification as part of
903 its argument, limiting the functions selected by the regex to those
904 in the specified file.
906 * Support for remote debugging Windows and SymbianOS shared libraries
907 from Unix hosts has been improved. Non Windows GDB builds now can
908 understand target reported file names that follow MS-DOS based file
909 system semantics, such as file names that include drive letters and
910 use the backslash character as directory separator. This makes it
911 possible to transparently use the "set sysroot" and "set
912 solib-search-path" on Unix hosts to point as host copies of the
913 target's shared libraries. See the new command "set
914 target-file-system-kind" described below, and the "Commands to
915 specify files" section in the user manual for more information.
919 eval template, expressions...
920 Convert the values of one or more expressions under the control
921 of the string template to a command line, and call it.
923 set target-file-system-kind unix|dos-based|auto
924 show target-file-system-kind
925 Set or show the assumed file system kind for target reported file
928 save breakpoints <filename>
929 Save all current breakpoint definitions to a file suitable for use
930 in a later debugging session. To read the saved breakpoint
931 definitions, use the `source' command.
933 `save tracepoints' is a new alias for `save-tracepoints'. The latter
936 info static-tracepoint-markers
937 Display information about static tracepoint markers in the target.
939 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
940 Define a static tracepoint by probing a marker at the given
941 function, line, address, or marker ID.
945 Enable and disable observer mode.
947 set may-write-registers on|off
948 set may-write-memory on|off
949 set may-insert-breakpoints on|off
950 set may-insert-tracepoints on|off
951 set may-insert-fast-tracepoints on|off
952 set may-interrupt on|off
953 Set individual permissions for GDB effects on the target. Note that
954 some of these settings can have undesirable or surprising
955 consequences, particularly when changed in the middle of a session.
956 For instance, disabling the writing of memory can prevent
957 breakpoints from being inserted, cause single-stepping to fail, or
958 even crash your program, if you disable after breakpoints have been
959 inserted. However, GDB should not crash.
961 set record memory-query on|off
962 show record memory-query
963 Control whether to stop the inferior if memory changes caused
964 by an instruction cannot be recorded.
969 The disassemble command now supports "start,+length" form of two arguments.
973 ** GDB now provides a new directory location, called the python directory,
974 where Python scripts written for GDB can be installed. The location
975 of that directory is <data-directory>/python, where <data-directory>
976 is the GDB data directory. For more details, see section `Scripting
977 GDB using Python' in the manual.
979 ** The GDB Python API now has access to breakpoints, symbols, symbol
980 tables, program spaces, inferiors, threads and frame's code blocks.
981 Additionally, GDB Parameters can now be created from the API, and
982 manipulated via set/show in the CLI.
984 ** New functions gdb.target_charset, gdb.target_wide_charset,
985 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
987 ** New exception gdb.GdbError.
989 ** Pretty-printers are now also looked up in the current program space.
991 ** Pretty-printers can now be individually enabled and disabled.
993 ** GDB now looks for names of Python scripts to auto-load in a
994 special section named `.debug_gdb_scripts', in addition to looking
995 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
997 * Tracepoint actions were unified with breakpoint commands. In particular,
998 there are no longer differences in "info break" output for breakpoints and
999 tracepoints and the "commands" command can be used for both tracepoints and
1000 regular breakpoints.
1004 ARM Symbian arm*-*-symbianelf*
1006 * D language support.
1007 GDB now supports debugging programs written in the D programming
1010 * GDB now supports the extended ptrace interface for PowerPC which is
1011 available since Linux kernel version 2.6.34. This automatically enables
1012 any hardware breakpoints and additional hardware watchpoints available in
1013 the processor. The old ptrace interface exposes just one hardware
1014 watchpoint and no hardware breakpoints.
1016 * GDB is now able to use the Data Value Compare (DVC) register available on
1017 embedded PowerPC processors to implement in hardware simple watchpoint
1018 conditions of the form:
1020 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1022 This works in native GDB running on Linux kernels with the extended ptrace
1023 interface mentioned above.
1025 *** Changes in GDB 7.1
1029 ** Namespace Support
1031 GDB now supports importing of namespaces in C++. This enables the
1032 user to inspect variables from imported namespaces. Support for
1033 namepace aliasing has also been added. So, if a namespace is
1034 aliased in the current scope (e.g. namepace C=A; ) the user can
1035 print variables using the alias (e.g. (gdb) print C::x).
1039 All known bugs relating to the printing of virtual base class were
1040 fixed. It is now possible to call overloaded static methods using a
1045 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1046 and reinterpret_cast<> are now handled by the C++ expression parser.
1050 Xilinx MicroBlaze microblaze-*-*
1055 Xilinx MicroBlaze microblaze
1058 * Multi-program debugging.
1060 GDB now has support for multi-program (a.k.a. multi-executable or
1061 multi-exec) debugging. This allows for debugging multiple inferiors
1062 simultaneously each running a different program under the same GDB
1063 session. See "Debugging Multiple Inferiors and Programs" in the
1064 manual for more information. This implied some user visible changes
1065 in the multi-inferior support. For example, "info inferiors" now
1066 lists inferiors that are not running yet or that have exited
1067 already. See also "New commands" and "New options" below.
1069 * New tracing features
1071 GDB's tracepoint facility now includes several new features:
1073 ** Trace state variables
1075 GDB tracepoints now include support for trace state variables, which
1076 are variables managed by the target agent during a tracing
1077 experiment. They are useful for tracepoints that trigger each
1078 other, so for instance one tracepoint can count hits in a variable,
1079 and then a second tracepoint has a condition that is true when the
1080 count reaches a particular value. Trace state variables share the
1081 $-syntax of GDB convenience variables, and can appear in both
1082 tracepoint actions and condition expressions. Use the "tvariable"
1083 command to create, and "info tvariables" to view; see "Trace State
1084 Variables" in the manual for more detail.
1088 GDB now includes an option for defining fast tracepoints, which
1089 targets may implement more efficiently, such as by installing a jump
1090 into the target agent rather than a trap instruction. The resulting
1091 speedup can be by two orders of magnitude or more, although the
1092 tradeoff is that some program locations on some target architectures
1093 might not allow fast tracepoint installation, for instance if the
1094 instruction to be replaced is shorter than the jump. To request a
1095 fast tracepoint, use the "ftrace" command, with syntax identical to
1096 the regular trace command.
1098 ** Disconnected tracing
1100 It is now possible to detach GDB from the target while it is running
1101 a trace experiment, then reconnect later to see how the experiment
1102 is going. In addition, a new variable disconnected-tracing lets you
1103 tell the target agent whether to continue running a trace if the
1104 connection is lost unexpectedly.
1108 GDB now has the ability to save the trace buffer into a file, and
1109 then use that file as a target, similarly to you can do with
1110 corefiles. You can select trace frames, print data that was
1111 collected in them, and use tstatus to display the state of the
1112 tracing run at the moment that it was saved. To create a trace
1113 file, use "tsave <filename>", and to use it, do "target tfile
1116 ** Circular trace buffer
1118 You can ask the target agent to handle the trace buffer as a
1119 circular buffer, discarding the oldest trace frames to make room for
1120 newer ones, by setting circular-trace-buffer to on. This feature may
1121 not be available for all target agents.
1126 The disassemble command, when invoked with two arguments, now requires
1127 the arguments to be comma-separated.
1130 The info variables command now displays variable definitions. Files
1131 which only declare a variable are not shown.
1134 The source command is now capable of sourcing Python scripts.
1135 This feature is dependent on the debugger being build with Python
1138 Related to this enhancement is also the introduction of a new command
1139 "set script-extension" (see below).
1141 * New commands (for set/show, see "New options" below)
1143 record save [<FILENAME>]
1144 Save a file (in core file format) containing the process record
1145 execution log for replay debugging at a later time.
1147 record restore <FILENAME>
1148 Restore the process record execution log that was saved at an
1149 earlier time, for replay debugging.
1151 add-inferior [-copies <N>] [-exec <FILENAME>]
1154 clone-inferior [-copies <N>] [ID]
1155 Make a new inferior ready to execute the same program another
1156 inferior has loaded.
1161 maint info program-spaces
1162 List the program spaces loaded into GDB.
1164 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1165 show remote interrupt-sequence
1166 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1167 as the sequence to the remote target in order to interrupt the execution.
1168 Ctrl-C is a default. Some system prefers BREAK which is high level of
1169 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1170 Magic SysRq g. It is BREAK signal and character 'g'.
1172 set remote interrupt-on-connect [on | off]
1173 show remote interrupt-on-connect
1174 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1175 remote target when gdb connects to it. This is needed when you debug
1178 set remotebreak [on | off]
1180 Deprecated. Use "set/show remote interrupt-sequence" instead.
1182 tvariable $NAME [ = EXP ]
1183 Create or modify a trace state variable.
1186 List trace state variables and their values.
1188 delete tvariable $NAME ...
1189 Delete one or more trace state variables.
1192 Evaluate the given expressions without collecting anything into the
1193 trace buffer. (Valid in tracepoint actions only.)
1195 ftrace FN / FILE:LINE / *ADDR
1196 Define a fast tracepoint at the given function, line, or address.
1198 * New expression syntax
1200 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1201 GDB now parses 0b101010 identically with 42.
1205 set follow-exec-mode new|same
1206 show follow-exec-mode
1207 Control whether GDB reuses the same inferior across an exec call or
1208 creates a new one. This is useful to be able to restart the old
1209 executable after the inferior having done an exec call.
1211 set default-collect EXPR, ...
1212 show default-collect
1213 Define a list of expressions to be collected at each tracepoint.
1214 This is a useful way to ensure essential items are not overlooked,
1215 such as registers or a critical global variable.
1217 set disconnected-tracing
1218 show disconnected-tracing
1219 If set to 1, the target is instructed to continue tracing if it
1220 loses its connection to GDB. If 0, the target is to stop tracing
1223 set circular-trace-buffer
1224 show circular-trace-buffer
1225 If set to on, the target is instructed to use a circular trace buffer
1226 and discard the oldest trace frames instead of stopping the trace due
1227 to a full trace buffer. If set to off, the trace stops when the buffer
1228 fills up. Some targets may not support this.
1230 set script-extension off|soft|strict
1231 show script-extension
1232 If set to "off", the debugger does not perform any script language
1233 recognition, and all sourced files are assumed to be GDB scripts.
1234 If set to "soft" (the default), files are sourced according to
1235 filename extension, falling back to GDB scripts if the first
1237 If set to "strict", files are sourced according to filename extension.
1239 set ada trust-PAD-over-XVS on|off
1240 show ada trust-PAD-over-XVS
1241 If off, activate a workaround against a bug in the debugging information
1242 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1243 the GCC sources for more information about the GNAT encoding and
1244 PAD types in particular). It is always safe to set this option to
1245 off, but this introduces a slight performance penalty. The default
1248 * Python API Improvements
1250 ** GDB provides the new class gdb.LazyString. This is useful in
1251 some pretty-printing cases. The new method gdb.Value.lazy_string
1252 provides a simple way to create objects of this type.
1254 ** The fields returned by gdb.Type.fields now have an
1255 `is_base_class' attribute.
1257 ** The new method gdb.Type.range returns the range of an array type.
1259 ** The new method gdb.parse_and_eval can be used to parse and
1260 evaluate an expression.
1262 * New remote packets
1265 Define a trace state variable.
1268 Get the current value of a trace state variable.
1271 Set desired tracing behavior upon disconnection.
1274 Set the trace buffer to be linear or circular.
1277 Get data about the tracepoints currently in use.
1281 Process record now works correctly with hardware watchpoints.
1283 Multiple bug fixes have been made to the mips-irix port, making it
1284 much more reliable. In particular:
1285 - Debugging threaded applications is now possible again. Previously,
1286 GDB would hang while starting the program, or while waiting for
1287 the program to stop at a breakpoint.
1288 - Attaching to a running process no longer hangs.
1289 - An error occurring while loading a core file has been fixed.
1290 - Changing the value of the PC register now works again. This fixes
1291 problems observed when using the "jump" command, or when calling
1292 a function from GDB, or even when assigning a new value to $pc.
1293 - With the "finish" and "return" commands, the return value for functions
1294 returning a small array is now correctly printed.
1295 - It is now possible to break on shared library code which gets executed
1296 during a shared library init phase (code executed while executing
1297 their .init section). Previously, the breakpoint would have no effect.
1298 - GDB is now able to backtrace through the signal handler for
1299 non-threaded programs.
1301 PIE (Position Independent Executable) programs debugging is now supported.
1302 This includes debugging execution of PIC (Position Independent Code) shared
1303 libraries although for that, it should be possible to run such libraries as an
1306 *** Changes in GDB 7.0
1308 * GDB now has an interface for JIT compilation. Applications that
1309 dynamically generate code can create symbol files in memory and register
1310 them with GDB. For users, the feature should work transparently, and
1311 for JIT developers, the interface is documented in the GDB manual in the
1312 "JIT Compilation Interface" chapter.
1314 * Tracepoints may now be conditional. The syntax is as for
1315 breakpoints; either an "if" clause appended to the "trace" command,
1316 or the "condition" command is available. GDB sends the condition to
1317 the target for evaluation using the same bytecode format as is used
1318 for tracepoint actions.
1320 * The disassemble command now supports: an optional /r modifier, print the
1321 raw instructions in hex as well as in symbolic form, and an optional /m
1322 modifier to print mixed source+assembly.
1324 * Process record and replay
1326 In a architecture environment that supports ``process record and
1327 replay'', ``process record and replay'' target can record a log of
1328 the process execution, and replay it with both forward and reverse
1331 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1332 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1333 set execution-direction {forward|reverse}, for targets that support
1336 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1337 feature is available with a native GDB running on kernel version
1340 * GDB now has support for multi-byte and wide character sets on the
1341 target. Strings whose character type is wchar_t, char16_t, or
1342 char32_t are now correctly printed. GDB supports wide- and unicode-
1343 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1344 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1345 `printf'. This feature requires iconv to work properly; if your
1346 system does not have a working iconv, GDB can use GNU libiconv. See
1347 the installation instructions for more information.
1349 * GDB now supports automatic retrieval of shared library files from
1350 remote targets. To use this feature, specify a system root that begins
1351 with the `remote:' prefix, either via the `set sysroot' command or via
1352 the `--with-sysroot' configure-time option.
1354 * "info sharedlibrary" now takes an optional regex of libraries to show,
1355 and it now reports if a shared library has no debugging information.
1357 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1358 now complete on file names.
1360 * When completing in expressions, gdb will attempt to limit
1361 completions to allowable structure or union fields, where appropriate.
1362 For instance, consider:
1364 # struct example { int f1; double f2; };
1365 # struct example variable;
1368 If the user types TAB at the end of this command line, the available
1369 completions will be "f1" and "f2".
1371 * Inlined functions are now supported. They show up in backtraces, and
1372 the "step", "next", and "finish" commands handle them automatically.
1374 * GDB now supports the token-splicing (##) and stringification (#)
1375 operators when expanding macros. It also supports variable-arity
1378 * GDB now supports inspecting extra signal information, exported by
1379 the new $_siginfo convenience variable. The feature is currently
1380 implemented on linux ARM, i386 and amd64.
1382 * GDB can now display the VFP floating point registers and NEON vector
1383 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1384 can provide these registers (requires Linux 2.6.30 or later). Remote
1385 and simulator targets may also provide them.
1387 * New remote packets
1390 Search memory for a sequence of bytes.
1393 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1394 operation over reliable transport links. Use of this packet is
1395 controlled by the `set remote noack-packet' command.
1398 Kill the process with the specified process ID. Use this in preference
1399 to `k' when multiprocess protocol extensions are supported.
1402 Obtains additional operating system information
1406 Read or write additional signal information.
1408 * Removed remote protocol undocumented extension
1410 An undocumented extension to the remote protocol's `S' stop reply
1411 packet that permited the stub to pass a process id was removed.
1412 Remote servers should use the `T' stop reply packet instead.
1414 * GDB now supports multiple function calling conventions according to the
1415 DWARF-2 DW_AT_calling_convention function attribute.
1417 * The SH target utilizes the aforementioned change to distinguish between gcc
1418 and Renesas calling convention. It also adds the new CLI commands
1419 `set/show sh calling-convention'.
1421 * GDB can now read compressed debug sections, as produced by GNU gold
1422 with the --compress-debug-sections=zlib flag.
1424 * 64-bit core files are now supported on AIX.
1426 * Thread switching is now supported on Tru64.
1428 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1429 which will be allocated using malloc later in program execution.
1431 * The qXfer:libraries:read remote procotol packet now allows passing a
1432 list of section offsets.
1434 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1435 conditions handling signals delivered during attach or thread creation
1436 have also been fixed.
1438 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1439 From the user's standpoint, all unqualified instances of True and False
1440 are treated as the standard definitions, regardless of context.
1442 * GDB now parses C++ symbol and type names more flexibly. For
1445 template<typename T> class C { };
1448 GDB will now correctly handle all of:
1450 ptype C<char const *>
1451 ptype C<char const*>
1452 ptype C<const char *>
1453 ptype C<const char*>
1455 * New features in the GDB remote stub, gdbserver
1457 - The "--wrapper" command-line argument tells gdbserver to use a
1458 wrapper program to launch programs for debugging.
1460 - On PowerPC and S/390 targets, it is now possible to use a single
1461 gdbserver executable to debug both 32-bit and 64-bit programs.
1462 (This requires gdbserver itself to be built as a 64-bit executable.)
1464 - gdbserver uses the new noack protocol mode for TCP connections to
1465 reduce communications latency, if also supported and enabled in GDB.
1467 - Support for the sparc64-linux-gnu target is now included in
1470 - The amd64-linux build of gdbserver now supports debugging both
1471 32-bit and 64-bit programs.
1473 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1474 now support hardware watchpoints, and will use them automatically
1479 GDB now has support for scripting using Python. Whether this is
1480 available is determined at configure time.
1482 New GDB commands can now be written in Python.
1484 * Ada tasking support
1486 Ada tasks can now be inspected in GDB. The following commands have
1490 Print the list of Ada tasks.
1492 Print detailed information about task number N.
1494 Print the task number of the current task.
1496 Switch the context of debugging to task number N.
1498 * Support for user-defined prefixed commands. The "define" command can
1499 add new commands to existing prefixes, e.g. "target".
1501 * Multi-inferior, multi-process debugging.
1503 GDB now has generalized support for multi-inferior debugging. See
1504 "Debugging Multiple Inferiors" in the manual for more information.
1505 Although availability still depends on target support, the command
1506 set is more uniform now. The GNU/Linux specific multi-forks support
1507 has been migrated to this new framework. This implied some user
1508 visible changes; see "New commands" and also "Removed commands"
1511 * Target descriptions can now describe the target OS ABI. See the
1512 "Target Description Format" section in the user manual for more
1515 * Target descriptions can now describe "compatible" architectures
1516 to indicate that the target can execute applications for a different
1517 architecture in addition to those for the main target architecture.
1518 See the "Target Description Format" section in the user manual for
1521 * Multi-architecture debugging.
1523 GDB now includes general supports for debugging applications on
1524 hybrid systems that use more than one single processor architecture
1525 at the same time. Each such hybrid architecture still requires
1526 specific support to be added. The only hybrid architecture supported
1527 in this version of GDB is the Cell Broadband Engine.
1529 * GDB now supports integrated debugging of Cell/B.E. applications that
1530 use both the PPU and SPU architectures. To enable support for hybrid
1531 Cell/B.E. debugging, you need to configure GDB to support both the
1532 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1533 --enable-targets configure option.
1535 * Non-stop mode debugging.
1537 For some targets, GDB now supports an optional mode of operation in
1538 which you can examine stopped threads while other threads continue
1539 to execute freely. This is referred to as non-stop mode, with the
1540 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1541 section in the user manual for more information.
1543 To be able to support remote non-stop debugging, a remote stub needs
1544 to implement the non-stop mode remote protocol extensions, as
1545 described in the "Remote Non-Stop" section of the user manual. The
1546 GDB remote stub, gdbserver, has been adjusted to support these
1547 extensions on linux targets.
1549 * New commands (for set/show, see "New options" below)
1551 catch syscall [NAME(S) | NUMBER(S)]
1552 Catch system calls. Arguments, which should be names of system
1553 calls or their numbers, mean catch only those syscalls. Without
1554 arguments, every syscall will be caught. When the inferior issues
1555 any of the specified syscalls, GDB will stop and announce the system
1556 call, both when it is called and when its call returns. This
1557 feature is currently available with a native GDB running on the
1558 Linux Kernel, under the following architectures: x86, x86_64,
1559 PowerPC and PowerPC64.
1561 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1563 Search memory for a sequence of bytes.
1565 maint set python print-stack
1566 maint show python print-stack
1567 Show a stack trace when an error is encountered in a Python script.
1570 Invoke CODE by passing it to the Python interpreter.
1575 These allow macros to be defined, undefined, and listed
1579 Show operating system information about processes.
1582 List the inferiors currently under GDB's control.
1585 Switch focus to inferior number NUM.
1588 Detach from inferior number NUM.
1591 Kill inferior number NUM.
1595 set spu stop-on-load
1596 show spu stop-on-load
1597 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1599 set spu auto-flush-cache
1600 show spu auto-flush-cache
1601 Control whether to automatically flush the software-managed cache
1602 during Cell/B.E. debugging.
1604 set sh calling-convention
1605 show sh calling-convention
1606 Control the calling convention used when calling SH target functions.
1609 show debug timestamp
1610 Control display of timestamps with GDB debugging output.
1612 set disassemble-next-line
1613 show disassemble-next-line
1614 Control display of disassembled source lines or instructions when
1617 set remote noack-packet
1618 show remote noack-packet
1619 Set/show the use of remote protocol QStartNoAckMode packet. See above
1620 under "New remote packets."
1622 set remote query-attached-packet
1623 show remote query-attached-packet
1624 Control use of remote protocol `qAttached' (query-attached) packet.
1626 set remote read-siginfo-object
1627 show remote read-siginfo-object
1628 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1631 set remote write-siginfo-object
1632 show remote write-siginfo-object
1633 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1636 set remote reverse-continue
1637 show remote reverse-continue
1638 Control use of remote protocol 'bc' (reverse-continue) packet.
1640 set remote reverse-step
1641 show remote reverse-step
1642 Control use of remote protocol 'bs' (reverse-step) packet.
1644 set displaced-stepping
1645 show displaced-stepping
1646 Control displaced stepping mode. Displaced stepping is a way to
1647 single-step over breakpoints without removing them from the debuggee.
1648 Also known as "out-of-line single-stepping".
1651 show debug displaced
1652 Control display of debugging info for displaced stepping.
1654 maint set internal-error
1655 maint show internal-error
1656 Control what GDB does when an internal error is detected.
1658 maint set internal-warning
1659 maint show internal-warning
1660 Control what GDB does when an internal warning is detected.
1665 Use a wrapper program to launch programs for debugging.
1667 set multiple-symbols (all|ask|cancel)
1668 show multiple-symbols
1669 The value of this variable can be changed to adjust the debugger behavior
1670 when an expression or a breakpoint location contains an ambiguous symbol
1671 name (an overloaded function name, for instance).
1673 set breakpoint always-inserted
1674 show breakpoint always-inserted
1675 Keep breakpoints always inserted in the target, as opposed to inserting
1676 them when resuming the target, and removing them when the target stops.
1677 This option can improve debugger performance on slow remote targets.
1679 set arm fallback-mode (arm|thumb|auto)
1680 show arm fallback-mode
1681 set arm force-mode (arm|thumb|auto)
1683 These commands control how ARM GDB determines whether instructions
1684 are ARM or Thumb. The default for both settings is auto, which uses
1685 the current CPSR value for instructions without symbols; previous
1686 versions of GDB behaved as if "set arm fallback-mode arm".
1688 set disable-randomization
1689 show disable-randomization
1690 Standalone programs run with the virtual address space randomization enabled
1691 by default on some platforms. This option keeps the addresses stable across
1692 multiple debugging sessions.
1696 Control whether other threads are stopped or not when some thread hits
1701 Requests that asynchronous execution is enabled in the target, if available.
1702 In this case, it's possible to resume target in the background, and interact
1703 with GDB while the target is running. "show target-async" displays the
1704 current state of asynchronous execution of the target.
1706 set target-wide-charset
1707 show target-wide-charset
1708 The target-wide-charset is the name of the character set that GDB
1709 uses when printing characters whose type is wchar_t.
1711 set tcp auto-retry (on|off)
1713 set tcp connect-timeout
1714 show tcp connect-timeout
1715 These commands allow GDB to retry failed TCP connections to a remote stub
1716 with a specified timeout period; this is useful if the stub is launched
1717 in parallel with GDB but may not be ready to accept connections immediately.
1719 set libthread-db-search-path
1720 show libthread-db-search-path
1721 Control list of directories which GDB will search for appropriate
1724 set schedule-multiple (on|off)
1725 show schedule-multiple
1726 Allow GDB to resume all threads of all processes or only threads of
1727 the current process.
1731 Use more aggressive caching for accesses to the stack. This improves
1732 performance of remote debugging (particularly backtraces) without
1733 affecting correctness.
1735 set interactive-mode (on|off|auto)
1736 show interactive-mode
1737 Control whether GDB runs in interactive mode (on) or not (off).
1738 When in interactive mode, GDB waits for the user to answer all
1739 queries. Otherwise, GDB does not wait and assumes the default
1740 answer. When set to auto (the default), GDB determines which
1741 mode to use based on the stdin settings.
1746 For program forks, this is replaced by the new more generic `info
1747 inferiors' command. To list checkpoints, you can still use the
1748 `info checkpoints' command, which was an alias for the `info forks'
1752 Replaced by the new `inferior' command. To switch between
1753 checkpoints, you can still use the `restart' command, which was an
1754 alias for the `fork' command.
1757 This is removed, since some targets don't have a notion of
1758 processes. To switch between processes, you can still use the
1759 `inferior' command using GDB's own inferior number.
1762 For program forks, this is replaced by the new more generic `kill
1763 inferior' command. To delete a checkpoint, you can still use the
1764 `delete checkpoint' command, which was an alias for the `delete
1768 For program forks, this is replaced by the new more generic `detach
1769 inferior' command. To detach a checkpoint, you can still use the
1770 `detach checkpoint' command, which was an alias for the `detach
1773 * New native configurations
1775 x86/x86_64 Darwin i[34567]86-*-darwin*
1777 x86_64 MinGW x86_64-*-mingw*
1781 Lattice Mico32 lm32-*
1782 x86 DICOS i[34567]86-*-dicos*
1783 x86_64 DICOS x86_64-*-dicos*
1786 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1787 (mingw32ce) debugging.
1793 These commands were actually not implemented on any target.
1795 *** Changes in GDB 6.8
1797 * New native configurations
1799 NetBSD/hppa hppa*-*netbsd*
1800 Xtensa GNU/Linux xtensa*-*-linux*
1804 NetBSD/hppa hppa*-*-netbsd*
1805 Xtensa GNU/Lunux xtensa*-*-linux*
1807 * Change in command line behavior -- corefiles vs. process ids.
1809 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1810 attaching to process NUMBER fails, GDB no longer attempts to open a
1811 core file named NUMBER. Attaching to a program using the -c option
1812 is no longer supported. Instead, use the '-p' or '--pid' options.
1814 * GDB can now be built as a native debugger for debugging Windows x86
1815 (mingw32) Portable Executable (PE) programs.
1817 * Pending breakpoints no longer change their number when their address
1820 * GDB now supports breakpoints with multiple locations,
1821 including breakpoints on C++ constructors, inside C++ templates,
1822 and in inlined functions.
1824 * GDB's ability to debug optimized code has been improved. GDB more
1825 accurately identifies function bodies and lexical blocks that occupy
1826 more than one contiguous range of addresses.
1828 * Target descriptions can now describe registers for PowerPC.
1830 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1831 registers on PowerPC targets.
1833 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1834 targets even when the libthread_db library is not available.
1836 * The GDB remote stub, gdbserver, now supports the new file transfer
1837 commands (remote put, remote get, and remote delete).
1839 * The GDB remote stub, gdbserver, now supports run and attach in
1840 extended-remote mode.
1842 * hppa*64*-*-hpux11* target broken
1843 The debugger is unable to start a program and fails with the following
1844 error: "Error trying to get information about dynamic linker".
1845 The gdb-6.7 release is also affected.
1847 * GDB now supports the --enable-targets= configure option to allow
1848 building a single GDB executable that supports multiple remote
1849 target architectures.
1851 * GDB now supports debugging C and C++ programs which use the
1852 Decimal Floating Point extension. In addition, the PowerPC target
1853 now has a set of pseudo-registers to inspect decimal float values
1854 stored in two consecutive float registers.
1856 * The -break-insert MI command can optionally create pending
1859 * Improved support for debugging Ada
1860 Many improvements to the Ada language support have been made. These
1862 - Better support for Ada2005 interface types
1863 - Improved handling of arrays and slices in general
1864 - Better support for Taft-amendment types
1865 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1867 - Improved command completion in Ada
1870 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1875 set print frame-arguments (all|scalars|none)
1876 show print frame-arguments
1877 The value of this variable can be changed to control which argument
1878 values should be printed by the debugger when displaying a frame.
1883 Transfer files to and from a remote target, and delete remote files.
1890 Transfer files to and from a remote target, and delete remote files.
1892 * New remote packets
1899 Open, close, read, write, and delete files on the remote system.
1902 Attach to an existing process on the remote system, in extended-remote
1906 Run a new process on the remote system, in extended-remote mode.
1908 *** Changes in GDB 6.7
1910 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1911 bfd, libiberty and opcodes, as revealed by static analysis donated by
1912 Coverity, Inc. (http://scan.coverity.com).
1914 * When looking up multiply-defined global symbols, GDB will now prefer the
1915 symbol definition in the current shared library if it was built using the
1916 -Bsymbolic linker option.
1918 * When the Text User Interface (TUI) is not configured, GDB will now
1919 recognize the -tui command-line option and print a message that the TUI
1922 * The GDB remote stub, gdbserver, now has lower overhead for high
1923 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1925 * GDB for MIPS targets now autodetects whether a remote target provides
1926 32-bit or 64-bit register values.
1928 * Support for C++ member pointers has been improved.
1930 * GDB now understands XML target descriptions, which specify the
1931 target's overall architecture. GDB can read a description from
1932 a local file or over the remote serial protocol.
1934 * Vectors of single-byte data use a new integer type which is not
1935 automatically displayed as character or string data.
1937 * The /s format now works with the print command. It displays
1938 arrays of single-byte integers and pointers to single-byte integers
1941 * Target descriptions can now describe target-specific registers,
1942 for architectures which have implemented the support (currently
1943 only ARM, M68K, and MIPS).
1945 * GDB and the GDB remote stub, gdbserver, now support the XScale
1948 * The GDB remote stub, gdbserver, has been updated to support
1949 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1950 has been rewritten to use the standard GDB remote protocol.
1952 * GDB can now step into C++ functions which are called through thunks.
1954 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1956 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1957 layout. It also supports a TextSeg= and DataSeg= response when only
1958 segment base addresses (rather than offsets) are available.
1960 * The /i format now outputs any trailing branch delay slot instructions
1961 immediately following the last instruction within the count specified.
1963 * The GDB remote protocol "T" stop reply packet now supports a
1964 "library" response. Combined with the new "qXfer:libraries:read"
1965 packet, this response allows GDB to debug shared libraries on targets
1966 where the operating system manages the list of loaded libraries (e.g.
1967 Windows and SymbianOS).
1969 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1970 (DLLs) on Windows and Windows CE targets.
1972 * GDB now supports a faster verification that a .debug file matches its binary
1973 according to its build-id signature, if the signature is present.
1979 Enable or disable hardware flow control (RTS/CTS) on the serial port
1980 when debugging using remote targets.
1982 set mem inaccessible-by-default
1983 show mem inaccessible-by-default
1984 If the target supplies a memory map, for instance via the remote
1985 protocol's "qXfer:memory-map:read" packet, setting this variable
1986 prevents GDB from accessing memory outside the memory map. This
1987 is useful for targets with memory mapped registers or which react
1988 badly to accesses of unmapped address space.
1990 set breakpoint auto-hw
1991 show breakpoint auto-hw
1992 If the target supplies a memory map, for instance via the remote
1993 protocol's "qXfer:memory-map:read" packet, setting this variable
1994 lets GDB use hardware breakpoints automatically for memory regions
1995 where it can not use software breakpoints. This covers both the
1996 "break" command and internal breakpoints used for other commands
1997 including "next" and "finish".
2000 catch exception unhandled
2001 Stop the program execution when Ada exceptions are raised.
2004 Stop the program execution when an Ada assertion failed.
2008 Set an alternate system root for target files. This is a more
2009 general version of "set solib-absolute-prefix", which is now
2010 an alias to "set sysroot".
2013 Provide extended SPU facility status information. This set of
2014 commands is available only when debugging the Cell/B.E. SPU
2017 * New native configurations
2019 OpenBSD/sh sh*-*openbsd*
2022 unset tdesc filename
2024 Use the specified local file as an XML target description, and do
2025 not query the target for its built-in description.
2029 OpenBSD/sh sh*-*-openbsd*
2030 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2031 Toshiba Media Processor mep-elf
2033 * New remote packets
2036 Ignore the specified signals; pass them directly to the debugged program
2037 without stopping other threads or reporting them to GDB.
2039 qXfer:features:read:
2040 Read an XML target description from the target, which describes its
2045 Read or write contents of an spufs file on the target system. These
2046 packets are available only on the Cell/B.E. SPU architecture.
2048 qXfer:libraries:read:
2049 Report the loaded shared libraries. Combined with new "T" packet
2050 response, this packet allows GDB to debug shared libraries on
2051 targets where the operating system manages the list of loaded
2052 libraries (e.g. Windows and SymbianOS).
2056 Support for these obsolete configurations has been removed.
2064 i[34567]86-*-lynxos*
2065 i[34567]86-*-netware*
2066 i[34567]86-*-sco3.2v5*
2067 i[34567]86-*-sco3.2v4*
2069 i[34567]86-*-sysv4.2*
2072 i[34567]86-*-unixware2*
2073 i[34567]86-*-unixware*
2082 * Other removed features
2089 Various m68k-only ROM monitors.
2096 Various Renesas ROM monitors and debugging interfaces for SH and
2101 Support for a Macraigor serial interface to on-chip debugging.
2102 GDB does not directly support the newer parallel or USB
2107 A debug information format. The predecessor to DWARF 2 and
2108 DWARF 3, which are still supported.
2110 Support for the HP aCC compiler on HP-UX/PA-RISC
2112 SOM-encapsulated symbolic debugging information, automatic
2113 invocation of pxdb, and the aCC custom C++ ABI. This does not
2114 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2115 with aCC can still be debugged on an assembly level.
2117 MIPS ".pdr" sections
2119 A MIPS-specific format used to describe stack frame layout
2120 in debugging information.
2124 GDB could work with an older version of Guile to debug
2125 the interpreter and Scheme programs running in it.
2127 set mips stack-arg-size
2128 set mips saved-gpreg-size
2130 Use "set mips abi" to control parameter passing for MIPS.
2132 *** Changes in GDB 6.6
2137 Cell Broadband Engine SPU spu-elf
2139 * GDB can now be configured as a cross-debugger targeting native Windows
2140 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2141 running on a Windows system over TCP/IP to debug Windows programs.
2143 * The GDB remote stub, gdbserver, has been updated to support Windows and
2144 Cygwin debugging. Both single-threaded and multi-threaded programs are
2147 * The "set trust-readonly-sections" command works again. This command was
2148 broken in GDB 6.3, 6.4, and 6.5.
2150 * The "load" command now supports writing to flash memory, if the remote
2151 stub provides the required support.
2153 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2154 longer requires symbolic debug information (e.g. DWARF-2).
2159 unset substitute-path
2160 show substitute-path
2161 Manage a list of substitution rules that GDB uses to rewrite the name
2162 of the directories where the sources are located. This can be useful
2163 for instance when the sources were moved to a different location
2164 between compilation and debugging.
2168 Print each CLI command as it is executed. Each command is prefixed with
2169 a number of `+' symbols representing the nesting depth.
2170 The source command now has a `-v' option to enable the same feature.
2174 The ARM Demon monitor support (RDP protocol, "target rdp").
2176 Kernel Object Display, an embedded debugging feature which only worked with
2177 an obsolete version of Cisco IOS.
2179 The 'set download-write-size' and 'show download-write-size' commands.
2181 * New remote packets
2184 Tell a stub about GDB client features, and request remote target features.
2185 The first feature implemented is PacketSize, which allows the target to
2186 specify the size of packets it can handle - to minimize the number of
2187 packets required and improve performance when connected to a remote
2191 Fetch an OS auxilliary vector from the remote stub. This packet is a
2192 more efficient replacement for qPart:auxv:read.
2194 qXfer:memory-map:read:
2195 Fetch a memory map from the remote stub, including information about
2196 RAM, ROM, and flash memory devices.
2201 Erase and program a flash memory device.
2203 * Removed remote packets
2206 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2207 used it, and only gdbserver implemented it.
2209 *** Changes in GDB 6.5
2213 Renesas M32C/M16C m32c-elf
2215 Morpho Technologies ms1 ms1-elf
2219 init-if-undefined Initialize a convenience variable, but
2220 only if it doesn't already have a value.
2222 The following commands are presently only implemented for native GNU/Linux:
2224 checkpoint Save a snapshot of the program state.
2226 restart <n> Return the program state to a
2227 previously saved state.
2229 info checkpoints List currently saved checkpoints.
2231 delete-checkpoint <n> Delete a previously saved checkpoint.
2233 set|show detach-on-fork Tell gdb whether to detach from a newly
2234 forked process, or to keep debugging it.
2236 info forks List forks of the user program that
2237 are available to be debugged.
2239 fork <n> Switch to debugging one of several
2240 forks of the user program that are
2241 available to be debugged.
2243 delete-fork <n> Delete a fork from the list of forks
2244 that are available to be debugged (and
2245 kill the forked process).
2247 detach-fork <n> Delete a fork from the list of forks
2248 that are available to be debugged (and
2249 allow the process to continue).
2253 Morpho Technologies ms2 ms1-elf
2255 * Improved Windows host support
2257 GDB now builds as a cross debugger hosted on i686-mingw32, including
2258 native console support, and remote communications using either
2259 network sockets or serial ports.
2261 * Improved Modula-2 language support
2263 GDB can now print most types in the Modula-2 syntax. This includes:
2264 basic types, set types, record types, enumerated types, range types,
2265 pointer types and ARRAY types. Procedure var parameters are correctly
2266 printed and hexadecimal addresses and character constants are also
2267 written in the Modula-2 syntax. Best results can be obtained by using
2268 GNU Modula-2 together with the -gdwarf-2 command line option.
2272 The ARM rdi-share module.
2274 The Netware NLM debug server.
2276 *** Changes in GDB 6.4
2278 * New native configurations
2280 OpenBSD/arm arm*-*-openbsd*
2281 OpenBSD/mips64 mips64-*-openbsd*
2285 Morpho Technologies ms1 ms1-elf
2287 * New command line options
2289 --batch-silent As for --batch, but totally silent.
2290 --return-child-result The debugger will exist with the same value
2291 the child (debugged) program exited with.
2292 --eval-command COMMAND, -ex COMMAND
2293 Execute a single GDB CLI command. This may be
2294 specified multiple times and in conjunction
2295 with the --command (-x) option.
2297 * Deprecated commands removed
2299 The following commands, that were deprecated in 2000, have been
2303 set|show arm disassembly-flavor set|show arm disassembler
2304 othernames set arm disassembler
2305 set|show remotedebug set|show debug remote
2306 set|show archdebug set|show debug arch
2307 set|show eventdebug set|show debug event
2310 * New BSD user-level threads support
2312 It is now possible to debug programs using the user-level threads
2313 library on OpenBSD and FreeBSD. Currently supported (target)
2316 FreeBSD/amd64 x86_64-*-freebsd*
2317 FreeBSD/i386 i386-*-freebsd*
2318 OpenBSD/i386 i386-*-openbsd*
2320 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2321 are not yet supported.
2323 * New support for Matsushita MN10300 w/sim added
2324 (Work in progress). mn10300-elf.
2326 * REMOVED configurations and files
2328 VxWorks and the XDR protocol *-*-vxworks
2329 Motorola MCORE mcore-*-*
2330 National Semiconductor NS32000 ns32k-*-*
2332 * New "set print array-indexes" command
2334 After turning this setting "on", GDB prints the index of each element
2335 when displaying arrays. The default is "off" to preserve the previous
2338 * VAX floating point support
2340 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2342 * User-defined command support
2344 In addition to using $arg0..$arg9 for argument passing, it is now possible
2345 to use $argc to determine now many arguments have been passed. See the
2346 section on user-defined commands in the user manual for more information.
2348 *** Changes in GDB 6.3:
2350 * New command line option
2352 GDB now accepts -l followed by a number to set the timeout for remote
2355 * GDB works with GCC -feliminate-dwarf2-dups
2357 GDB now supports a more compact representation of DWARF-2 debug
2358 information using DW_FORM_ref_addr references. These are produced
2359 by GCC with the option -feliminate-dwarf2-dups and also by some
2360 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2361 to use -feliminate-dwarf2-dups.
2363 * Internationalization
2365 When supported by the host system, GDB will be built with
2366 internationalization (libintl). The task of marking up the sources is
2367 continued, we're looking forward to our first translation.
2371 Initial support for debugging programs compiled with the GNAT
2372 implementation of the Ada programming language has been integrated
2373 into GDB. In this release, support is limited to expression evaluation.
2375 * New native configurations
2377 GNU/Linux/m32r m32r-*-linux-gnu
2381 GDB's remote protocol now includes support for the 'p' packet. This
2382 packet is used to fetch individual registers from a remote inferior.
2384 * END-OF-LIFE registers[] compatibility module
2386 GDB's internal register infrastructure has been completely rewritten.
2387 The new infrastructure making possible the implementation of key new
2388 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2391 GDB 6.3 will be the last release to include the the registers[]
2392 compatibility module that allowed out-of-date configurations to
2393 continue to work. This change directly impacts the following
2403 powerpc bdm protocol
2405 Unless there is activity to revive these configurations, they will be
2406 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2408 * OBSOLETE configurations and files
2410 Configurations that have been declared obsolete in this release have
2411 been commented out. Unless there is activity to revive these
2412 configurations, the next release of GDB will have their sources
2413 permanently REMOVED.
2422 *** Changes in GDB 6.2.1:
2424 * MIPS `break main; run' gave an heuristic-fence-post warning
2426 When attempting to run even a simple program, a warning about
2427 heuristic-fence-post being hit would be reported. This problem has
2430 * MIPS IRIX 'long double' crashed GDB
2432 When examining a long double variable, GDB would get a segmentation
2433 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2434 IRIX long double values).
2438 A bug in the VAX stack code was causing problems with the "next"
2439 command. This problem has been fixed.
2441 *** Changes in GDB 6.2:
2443 * Fix for ``many threads''
2445 On GNU/Linux systems that use the NPTL threads library, a program
2446 rapidly creating and deleting threads would confuse GDB leading to the
2449 ptrace: No such process.
2450 thread_db_get_info: cannot get thread info: generic error
2452 This problem has been fixed.
2454 * "-async" and "-noasync" options removed.
2456 Support for the broken "-noasync" option has been removed (it caused
2459 * New ``start'' command.
2461 This command runs the program until the begining of the main procedure.
2463 * New BSD Kernel Data Access Library (libkvm) interface
2465 Using ``target kvm'' it is now possible to debug kernel core dumps and
2466 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2467 platforms. Currently supported (native-only) configurations are:
2469 FreeBSD/amd64 x86_64-*-freebsd*
2470 FreeBSD/i386 i?86-*-freebsd*
2471 NetBSD/i386 i?86-*-netbsd*
2472 NetBSD/m68k m68*-*-netbsd*
2473 NetBSD/sparc sparc-*-netbsd*
2474 OpenBSD/amd64 x86_64-*-openbsd*
2475 OpenBSD/i386 i?86-*-openbsd*
2476 OpenBSD/m68k m68*-openbsd*
2477 OpenBSD/sparc sparc-*-openbsd*
2479 * Signal trampoline code overhauled
2481 Many generic problems with GDB's signal handling code have been fixed.
2482 These include: backtraces through non-contiguous stacks; recognition
2483 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2484 call; backtrace through a signal trampoline; step into and out of
2485 signal handlers; and single-stepping in the signal trampoline.
2487 Please note that kernel bugs are a limiting factor here. These
2488 features have been shown to work on an s390 GNU/Linux system that
2489 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2491 * Cygwin support for DWARF 2 added.
2493 * New native configurations
2495 GNU/Linux/hppa hppa*-*-linux*
2496 OpenBSD/hppa hppa*-*-openbsd*
2497 OpenBSD/m68k m68*-*-openbsd*
2498 OpenBSD/m88k m88*-*-openbsd*
2499 OpenBSD/powerpc powerpc-*-openbsd*
2500 NetBSD/vax vax-*-netbsd*
2501 OpenBSD/vax vax-*-openbsd*
2503 * END-OF-LIFE frame compatibility module
2505 GDB's internal frame infrastructure has been completely rewritten.
2506 The new infrastructure making it possible to support key new features
2507 including DWARF 2 Call Frame Information. To aid in the task of
2508 migrating old configurations to this new infrastructure, a
2509 compatibility module, that allowed old configurations to continue to
2510 work, was also included.
2512 GDB 6.2 will be the last release to include this frame compatibility
2513 module. This change directly impacts the following configurations:
2523 Unless there is activity to revive these configurations, they will be
2524 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2526 * REMOVED configurations and files
2528 Sun 3, running SunOS 3 m68*-*-sunos3*
2529 Sun 3, running SunOS 4 m68*-*-sunos4*
2530 Sun 2, running SunOS 3 m68000-*-sunos3*
2531 Sun 2, running SunOS 4 m68000-*-sunos4*
2532 Motorola 680x0 running LynxOS m68*-*-lynxos*
2533 AT&T 3b1/Unix pc m68*-att-*
2534 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2535 decstation mips-dec-* mips-little-*
2536 riscos mips-*-riscos* mips-*-sysv*
2537 sonymips mips-sony-*
2538 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2540 *** Changes in GDB 6.1.1:
2542 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2544 The TUI (Text-mode User Interface) is now built as part of a default
2545 GDB configuration. It is enabled by either selecting the TUI with the
2546 command line option "-i=tui" or by running the separate "gdbtui"
2547 program. For more information on the TUI, see the manual "Debugging
2550 * Pending breakpoint support (also included in GDB 6.1)
2552 Support has been added to allow you to specify breakpoints in shared
2553 libraries that have not yet been loaded. If a breakpoint location
2554 cannot be found, and the "breakpoint pending" option is set to auto,
2555 GDB queries you if you wish to make the breakpoint pending on a future
2556 shared-library load. If and when GDB resolves the breakpoint symbol,
2557 the pending breakpoint is removed as one or more regular breakpoints
2560 Pending breakpoints are very useful for GCJ Java debugging.
2562 * Fixed ISO-C build problems
2564 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2565 non ISO-C code that stopped them being built using a more strict ISO-C
2566 compiler (e.g., IBM's C compiler).
2568 * Fixed build problem on IRIX 5
2570 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2571 wasn't able to compile compile on an IRIX 5 system.
2573 * Added execute permission to gdb/gdbserver/configure
2575 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2576 permission. This bug would cause configure to fail on a number of
2577 systems (Solaris, IRIX). Ref: server/519.
2579 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2581 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2582 has been updated to use constant array sizes.
2584 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2586 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2587 its generated DWARF Call Frame Info. This encoding was causing GDB to
2588 panic, that panic has been fixed. Ref: gdb/1628.
2590 * Fixed a problem when examining parameters in shared library code.
2592 When examining parameters in optimized shared library code generated
2593 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2594 not available''. GDB now correctly displays the variable's value.
2596 *** Changes in GDB 6.1:
2598 * Removed --with-mmalloc
2600 Support for the mmalloc memory manager has been removed, as it
2601 conflicted with the internal gdb byte cache.
2603 * Changes in AMD64 configurations
2605 The AMD64 target now includes the %cs and %ss registers. As a result
2606 the AMD64 remote protocol has changed; this affects the floating-point
2607 and SSE registers. If you rely on those registers for your debugging,
2608 you should upgrade gdbserver on the remote side.
2610 * Revised SPARC target
2612 The SPARC target has been completely revised, incorporating the
2613 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2614 support for LynxOS and SunOS 4 has been dropped. Calling functions
2615 from within GDB on operating systems with a non-executable stack
2616 (Solaris, OpenBSD) now works.
2620 GDB has a new C++ demangler which does a better job on the mangled
2621 names generated by current versions of g++. It also runs faster, so
2622 with this and other changes gdb should now start faster on large C++
2625 * DWARF 2 Location Expressions
2627 GDB support for location expressions has been extended to support function
2628 arguments and frame bases. Older versions of GDB could crash when they
2631 * C++ nested types and namespaces
2633 GDB's support for nested types and namespaces in C++ has been
2634 improved, especially if you use the DWARF 2 debugging format. (This
2635 is the default for recent versions of GCC on most platforms.)
2636 Specifically, if you have a class "Inner" defined within a class or
2637 namespace "Outer", then GDB realizes that the class's name is
2638 "Outer::Inner", not simply "Inner". This should greatly reduce the
2639 frequency of complaints about not finding RTTI symbols. In addition,
2640 if you are stopped at inside of a function defined within a namespace,
2641 GDB modifies its name lookup accordingly.
2643 * New native configurations
2645 NetBSD/amd64 x86_64-*-netbsd*
2646 OpenBSD/amd64 x86_64-*-openbsd*
2647 OpenBSD/alpha alpha*-*-openbsd*
2648 OpenBSD/sparc sparc-*-openbsd*
2649 OpenBSD/sparc64 sparc64-*-openbsd*
2651 * New debugging protocols
2653 M32R with SDI protocol m32r-*-elf*
2655 * "set prompt-escape-char" command deleted.
2657 The command "set prompt-escape-char" has been deleted. This command,
2658 and its very obscure effet on GDB's prompt, was never documented,
2659 tested, nor mentioned in the NEWS file.
2661 * OBSOLETE configurations and files
2663 Configurations that have been declared obsolete in this release have
2664 been commented out. Unless there is activity to revive these
2665 configurations, the next release of GDB will have their sources
2666 permanently REMOVED.
2668 Sun 3, running SunOS 3 m68*-*-sunos3*
2669 Sun 3, running SunOS 4 m68*-*-sunos4*
2670 Sun 2, running SunOS 3 m68000-*-sunos3*
2671 Sun 2, running SunOS 4 m68000-*-sunos4*
2672 Motorola 680x0 running LynxOS m68*-*-lynxos*
2673 AT&T 3b1/Unix pc m68*-att-*
2674 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2675 decstation mips-dec-* mips-little-*
2676 riscos mips-*-riscos* mips-*-sysv*
2677 sonymips mips-sony-*
2678 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2680 * REMOVED configurations and files
2682 SGI Irix-4.x mips-sgi-irix4 or iris4
2683 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2684 Z8000 simulator z8k-zilog-none or z8ksim
2685 Matsushita MN10200 w/simulator mn10200-*-*
2686 H8/500 simulator h8500-hitachi-hms or h8500hms
2687 HP/PA running BSD hppa*-*-bsd*
2688 HP/PA running OSF/1 hppa*-*-osf*
2689 HP/PA Pro target hppa*-*-pro*
2690 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2691 386BSD i[3456]86-*-bsd*
2692 Sequent family i[3456]86-sequent-sysv4*
2693 i[3456]86-sequent-sysv*
2694 i[3456]86-sequent-bsd*
2695 SPARC running LynxOS sparc-*-lynxos*
2696 SPARC running SunOS 4 sparc-*-sunos4*
2697 Tsqware Sparclet sparclet-*-*
2698 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2700 *** Changes in GDB 6.0:
2704 Support for debugging the Objective-C programming language has been
2705 integrated into GDB.
2707 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2709 DWARF 2's Call Frame Information makes available compiler generated
2710 information that more exactly describes the program's run-time stack.
2711 By using this information, GDB is able to provide more robust stack
2714 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2715 have been updated to use a new backtrace mechanism which includes
2716 DWARF 2 CFI support.
2720 GDB's remote protocol has been extended to include support for hosted
2721 file I/O (where the remote target uses GDB's file system). See GDB's
2722 remote protocol documentation for details.
2724 * All targets using the new architecture framework.
2726 All of GDB's targets have been updated to use the new internal
2727 architecture framework. The way is now open for future GDB releases
2728 to include cross-architecture native debugging support (i386 on amd64,
2731 * GNU/Linux's Thread Local Storage (TLS)
2733 GDB now includes support for for the GNU/Linux implementation of
2734 per-thread variables.
2736 * GNU/Linux's Native POSIX Thread Library (NPTL)
2738 GDB's thread code has been updated to work with either the new
2739 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2741 * Separate debug info.
2743 GDB, in conjunction with BINUTILS, now supports a mechanism for
2744 automatically loading debug information from a separate file. Instead
2745 of shipping full debug and non-debug versions of system libraries,
2746 system integrators can now instead ship just the stripped libraries
2747 and optional debug files.
2749 * DWARF 2 Location Expressions
2751 DWARF 2 Location Expressions allow the compiler to more completely
2752 describe the location of variables (even in optimized code) to the
2755 GDB now includes preliminary support for location expressions (support
2756 for DW_OP_piece is still missing).
2760 A number of long standing bugs that caused GDB to die while starting a
2761 Java application have been fixed. GDB's Java support is now
2762 considered "useable".
2764 * GNU/Linux support for fork, vfork, and exec.
2766 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2767 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2770 * GDB supports logging output to a file
2772 There are two new commands, "set logging" and "show logging", which can be
2773 used to capture GDB's output to a file.
2775 * The meaning of "detach" has changed for gdbserver
2777 The "detach" command will now resume the application, as documented. To
2778 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2781 * d10v, m68hc11 `regs' command deprecated
2783 The `info registers' command has been updated so that it displays the
2784 registers using a format identical to the old `regs' command.
2788 A new command, "maint set profile on/off", has been added. This command can
2789 be used to enable or disable profiling while running GDB, to profile a
2790 session or a set of commands. In addition there is a new configure switch,
2791 "--enable-profiling", which will cause GDB to be compiled with profiling
2792 data, for more informative profiling results.
2794 * Default MI syntax changed to "mi2".
2796 The default MI (machine interface) syntax, enabled by the command line
2797 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2798 "mi1", can be enabled by specifying the option "-i=mi1".
2800 Support for the original "mi0" syntax (included in GDB 5.0) has been
2803 Fix for gdb/192: removed extraneous space when displaying frame level.
2804 Fix for gdb/672: update changelist is now output in mi list format.
2805 Fix for gdb/702: a -var-assign that updates the value now shows up
2806 in a subsequent -var-update.
2808 * New native configurations.
2810 FreeBSD/amd64 x86_64-*-freebsd*
2812 * Multi-arched targets.
2814 HP/PA HPUX11 hppa*-*-hpux*
2815 Renesas M32R/D w/simulator m32r-*-elf*
2817 * OBSOLETE configurations and files
2819 Configurations that have been declared obsolete in this release have
2820 been commented out. Unless there is activity to revive these
2821 configurations, the next release of GDB will have their sources
2822 permanently REMOVED.
2824 Z8000 simulator z8k-zilog-none or z8ksim
2825 Matsushita MN10200 w/simulator mn10200-*-*
2826 H8/500 simulator h8500-hitachi-hms or h8500hms
2827 HP/PA running BSD hppa*-*-bsd*
2828 HP/PA running OSF/1 hppa*-*-osf*
2829 HP/PA Pro target hppa*-*-pro*
2830 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2831 Sequent family i[3456]86-sequent-sysv4*
2832 i[3456]86-sequent-sysv*
2833 i[3456]86-sequent-bsd*
2834 Tsqware Sparclet sparclet-*-*
2835 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2837 * REMOVED configurations and files
2840 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2841 IBM AIX PS/2 i[3456]86-*-aix
2842 i386 running Mach 3.0 i[3456]86-*-mach3*
2843 i386 running Mach i[3456]86-*-mach*
2844 i386 running OSF/1 i[3456]86-*osf1mk*
2845 HP/Apollo 68k Family m68*-apollo*-sysv*,
2847 m68*-hp-bsd*, m68*-hp-hpux*
2848 Argonaut Risc Chip (ARC) arc-*-*
2849 Mitsubishi D30V d30v-*-*
2850 Fujitsu FR30 fr30-*-elf*
2851 OS/9000 i[34]86-*-os9k
2852 I960 with MON960 i960-*-coff
2854 * MIPS $fp behavior changed
2856 The convenience variable $fp, for the MIPS, now consistently returns
2857 the address of the current frame's base. Previously, depending on the
2858 context, $fp could refer to either $sp or the current frame's base
2859 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2860 The GNU Source-Level Debugger''.
2862 *** Changes in GDB 5.3:
2864 * GNU/Linux shared library multi-threaded performance improved.
2866 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2867 `/proc', in preference to `ptrace' for memory reads. This may result
2868 in an improvement in the start-up time of multi-threaded, shared
2869 library applications when run under GDB. One GDB user writes: ``loads
2870 shared libs like mad''.
2872 * ``gdbserver'' now supports multi-threaded applications on some targets
2874 Support for debugging multi-threaded applications which use
2875 the GNU/Linux LinuxThreads package has been added for
2876 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2877 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2879 * GDB now supports C/C++ preprocessor macros.
2881 GDB now expands preprocessor macro invocations in C/C++ expressions,
2882 and provides various commands for showing macro definitions and how
2885 The new command `macro expand EXPRESSION' expands any macro
2886 invocations in expression, and shows the result.
2888 The new command `show macro MACRO-NAME' shows the definition of the
2889 macro named MACRO-NAME, and where it was defined.
2891 Most compilers don't include information about macros in the debugging
2892 information by default. In GCC 3.1, for example, you need to compile
2893 your program with the options `-gdwarf-2 -g3'. If the macro
2894 information is present in the executable, GDB will read it.
2896 * Multi-arched targets.
2898 DEC Alpha (partial) alpha*-*-*
2899 DEC VAX (partial) vax-*-*
2901 National Semiconductor NS32000 (partial) ns32k-*-*
2902 Motorola 68000 (partial) m68k-*-*
2903 Motorola MCORE mcore-*-*
2907 Fujitsu FRV architecture added by Red Hat frv*-*-*
2910 * New native configurations
2912 Alpha NetBSD alpha*-*-netbsd*
2913 SH NetBSD sh*-*-netbsdelf*
2914 MIPS NetBSD mips*-*-netbsd*
2915 UltraSPARC NetBSD sparc64-*-netbsd*
2917 * OBSOLETE configurations and files
2919 Configurations that have been declared obsolete in this release have
2920 been commented out. Unless there is activity to revive these
2921 configurations, the next release of GDB will have their sources
2922 permanently REMOVED.
2924 Mitsubishi D30V d30v-*-*
2925 OS/9000 i[34]86-*-os9k
2926 IBM AIX PS/2 i[3456]86-*-aix
2927 Fujitsu FR30 fr30-*-elf*
2928 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2929 Argonaut Risc Chip (ARC) arc-*-*
2930 i386 running Mach 3.0 i[3456]86-*-mach3*
2931 i386 running Mach i[3456]86-*-mach*
2932 i386 running OSF/1 i[3456]86-*osf1mk*
2933 HP/Apollo 68k Family m68*-apollo*-sysv*,
2935 m68*-hp-bsd*, m68*-hp-hpux*
2936 I960 with MON960 i960-*-coff
2938 * OBSOLETE languages
2940 CHILL, a Pascal like language used by telecommunications companies.
2942 * REMOVED configurations and files
2944 AMD 29k family via UDI a29k-amd-udi, udi29k
2945 A29K VxWorks a29k-*-vxworks
2946 AMD 29000 embedded, using EBMON a29k-none-none
2947 AMD 29000 embedded with COFF a29k-none-coff
2948 AMD 29000 embedded with a.out a29k-none-aout
2950 testsuite/gdb.hp/gdb.threads-hp/ directory
2952 * New command "set max-user-call-depth <nnn>"
2954 This command allows the user to limit the call depth of user-defined
2955 commands. The default is 1024.
2957 * Changes in FreeBSD/i386 native debugging.
2959 Support for the "generate-core-file" has been added.
2961 * New commands "dump", "append", and "restore".
2963 These commands allow data to be copied from target memory
2964 to a bfd-format or binary file (dump and append), and back
2965 from a file into memory (restore).
2967 * Improved "next/step" support on multi-processor Alpha Tru64.
2969 The previous single-step mechanism could cause unpredictable problems,
2970 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2971 of a software single-step mechanism prevents this.
2973 *** Changes in GDB 5.2.1:
2981 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2982 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2983 Fix, by Joel Brobecker imported from mainline.
2985 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2986 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2987 Fix, by Fred Fish, imported from mainline.
2989 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2990 Surprisingly enough, it works now.
2991 By Michal Ludvig, imported from mainline.
2993 i386 hardware watchpoint support:
2994 avoid misses on second run for some targets.
2995 By Pierre Muller, imported from mainline.
2997 *** Changes in GDB 5.2:
2999 * New command "set trust-readonly-sections on[off]".
3001 This command is a hint that tells gdb that read-only sections
3002 really are read-only (ie. that their contents will not change).
3003 In this mode, gdb will go to the object file rather than the
3004 target to read memory from read-only sections (such as ".text").
3005 This can be a significant performance improvement on some
3006 (notably embedded) targets.
3008 * New command "generate-core-file" (or "gcore").
3010 This new gdb command allows the user to drop a core file of the child
3011 process state at any time. So far it's been implemented only for
3012 GNU/Linux and Solaris, but should be relatively easily ported to other
3013 hosts. Argument is core file name (defaults to core.<pid>).
3015 * New command line option
3017 GDB now accepts --pid or -p followed by a process id.
3019 * Change in command line behavior -- corefiles vs. process ids.
3021 There is a subtle behavior in the way in which GDB handles
3022 command line arguments. The first non-flag argument is always
3023 a program to debug, but the second non-flag argument may either
3024 be a corefile or a process id. Previously, GDB would attempt to
3025 open the second argument as a corefile, and if that failed, would
3026 issue a superfluous error message and then attempt to attach it as
3027 a process. Now, if the second argument begins with a non-digit,
3028 it will be treated as a corefile. If it begins with a digit,
3029 GDB will attempt to attach it as a process, and if no such process
3030 is found, will then attempt to open it as a corefile.
3032 * Changes in ARM configurations.
3034 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3035 configuration is fully multi-arch.
3037 * New native configurations
3039 ARM NetBSD arm*-*-netbsd*
3040 x86 OpenBSD i[3456]86-*-openbsd*
3041 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3042 Sparc64 running FreeBSD sparc64-*-freebsd*
3046 Sanyo XStormy16 xstormy16-elf
3048 * OBSOLETE configurations and files
3050 Configurations that have been declared obsolete in this release have
3051 been commented out. Unless there is activity to revive these
3052 configurations, the next release of GDB will have their sources
3053 permanently REMOVED.
3055 AMD 29k family via UDI a29k-amd-udi, udi29k
3056 A29K VxWorks a29k-*-vxworks
3057 AMD 29000 embedded, using EBMON a29k-none-none
3058 AMD 29000 embedded with COFF a29k-none-coff
3059 AMD 29000 embedded with a.out a29k-none-aout
3061 testsuite/gdb.hp/gdb.threads-hp/ directory
3063 * REMOVED configurations and files
3065 TI TMS320C80 tic80-*-*
3067 PowerPC Solaris powerpcle-*-solaris*
3068 PowerPC Windows NT powerpcle-*-cygwin32
3069 PowerPC Netware powerpc-*-netware*
3070 Harris/CXUX m88k m88*-harris-cxux*
3071 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3072 ns32k-utek-sysv* ns32k-utek-*
3073 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3074 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3075 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3076 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3077 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3079 * Changes to command line processing
3081 The new `--args' feature can be used to specify command-line arguments
3082 for the inferior from gdb's command line.
3084 * Changes to key bindings
3086 There is a new `operate-and-get-next' function bound to `C-o'.
3088 *** Changes in GDB 5.1.1
3090 Fix compile problem on DJGPP.
3092 Fix a problem with floating-point registers on the i386 being
3095 Fix to stop GDB crashing on .debug_str debug info.
3097 Numerous documentation fixes.
3099 Numerous testsuite fixes.
3101 *** Changes in GDB 5.1:
3103 * New native configurations
3105 Alpha FreeBSD alpha*-*-freebsd*
3106 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3107 MIPS GNU/Linux mips*-*-linux*
3108 MIPS SGI Irix 6.x mips*-sgi-irix6*
3109 ia64 AIX ia64-*-aix*
3110 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3114 Motorola 68HC11 and 68HC12 m68hc11-elf
3116 UltraSparc running GNU/Linux sparc64-*-linux*
3118 * OBSOLETE configurations and files
3120 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3121 Harris/CXUX m88k m88*-harris-cxux*
3122 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3123 ns32k-utek-sysv* ns32k-utek-*
3124 TI TMS320C80 tic80-*-*
3126 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3127 PowerPC Solaris powerpcle-*-solaris*
3128 PowerPC Windows NT powerpcle-*-cygwin32
3129 PowerPC Netware powerpc-*-netware*
3130 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3131 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3132 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3133 Apple Macintosh (MPW) host N/A
3135 stuff.c (Program to stuff files into a specially prepared space in kdb)
3136 kdb-start.c (Main loop for the standalone kernel debugger)
3138 Configurations that have been declared obsolete in this release have
3139 been commented out. Unless there is activity to revive these
3140 configurations, the next release of GDB will have their sources
3141 permanently REMOVED.
3143 * REMOVED configurations and files
3145 Altos 3068 m68*-altos-*
3146 Convex c1-*-*, c2-*-*
3148 ARM RISCix arm-*-* (as host)
3152 * GDB has been converted to ISO C.
3154 GDB's source code has been converted to ISO C. In particular, the
3155 sources are fully protoized, and rely on standard headers being
3160 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3162 * The MI enabled by default.
3164 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3165 revised and enabled by default. Packages which use GDB as a debugging
3166 engine behind a UI or another front end are encouraged to switch to
3167 using the GDB/MI interface, instead of the old annotations interface
3168 which is now deprecated.
3170 * Support for debugging Pascal programs.
3172 GDB now includes support for debugging Pascal programs. The following
3173 main features are supported:
3175 - Pascal-specific data types such as sets;
3177 - automatic recognition of Pascal sources based on file-name
3180 - Pascal-style display of data types, variables, and functions;
3182 - a Pascal expression parser.
3184 However, some important features are not yet supported.
3186 - Pascal string operations are not supported at all;
3188 - there are some problems with boolean types;
3190 - Pascal type hexadecimal constants are not supported
3191 because they conflict with the internal variables format;
3193 - support for Pascal objects and classes is not full yet;
3195 - unlike Pascal, GDB is case-sensitive for symbol names.
3197 * Changes in completion.
3199 Commands such as `shell', `run' and `set args', which pass arguments
3200 to inferior programs, now complete on file names, similar to what
3201 users expect at the shell prompt.
3203 Commands which accept locations, such as `disassemble', `print',
3204 `breakpoint', `until', etc. now complete on filenames as well as
3205 program symbols. Thus, if you type "break foob TAB", and the source
3206 files linked into the programs include `foobar.c', that file name will
3207 be one of the candidates for completion. However, file names are not
3208 considered for completion after you typed a colon that delimits a file
3209 name from a name of a function in that file, as in "break foo.c:bar".
3211 `set demangle-style' completes on available demangling styles.
3213 * New platform-independent commands:
3215 It is now possible to define a post-hook for a command as well as a
3216 hook that runs before the command. For more details, see the
3217 documentation of `hookpost' in the GDB manual.
3219 * Changes in GNU/Linux native debugging.
3221 Support for debugging multi-threaded programs has been completely
3222 revised for all platforms except m68k and sparc. You can now debug as
3223 many threads as your system allows you to have.
3225 Attach/detach is supported for multi-threaded programs.
3227 Support for SSE registers was added for x86. This doesn't work for
3228 multi-threaded programs though.
3230 * Changes in MIPS configurations.
3232 Multi-arch support is enabled for all MIPS configurations.
3234 GDB can now be built as native debugger on SGI Irix 6.x systems for
3235 debugging n32 executables. (Debugging 64-bit executables is not yet
3238 * Unified support for hardware watchpoints in all x86 configurations.
3240 Most (if not all) native x86 configurations support hardware-assisted
3241 breakpoints and watchpoints in a unified manner. This support
3242 implements debug register sharing between watchpoints, which allows to
3243 put a virtually infinite number of watchpoints on the same address,
3244 and also supports watching regions up to 16 bytes with several debug
3247 The new maintenance command `maintenance show-debug-regs' toggles
3248 debugging print-outs in functions that insert, remove, and test
3249 watchpoints and hardware breakpoints.
3251 * Changes in the DJGPP native configuration.
3253 New command ``info dos sysinfo'' displays assorted information about
3254 the CPU, OS, memory, and DPMI server.
3256 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3257 display information about segment descriptors stored in GDT, LDT, and
3260 New commands ``info dos pde'' and ``info dos pte'' display entries
3261 from Page Directory and Page Tables (for now works with CWSDPMI only).
3262 New command ``info dos address-pte'' displays the Page Table entry for
3263 a given linear address.
3265 GDB can now pass command lines longer than 126 characters to the
3266 program being debugged (requires an update to the libdbg.a library
3267 which is part of the DJGPP development kit).
3269 DWARF2 debug info is now supported.
3271 It is now possible to `step' and `next' through calls to `longjmp'.
3273 * Changes in documentation.
3275 All GDB documentation was converted to GFDL, the GNU Free
3276 Documentation License.
3278 Tracepoints-related commands are now fully documented in the GDB
3281 TUI, the Text-mode User Interface, is now documented in the manual.
3283 Tracepoints-related commands are now fully documented in the GDB
3286 The "GDB Internals" manual now has an index. It also includes
3287 documentation of `ui_out' functions, GDB coding standards, x86
3288 hardware watchpoints, and memory region attributes.
3290 * GDB's version number moved to ``version.in''
3292 The Makefile variable VERSION has been replaced by the file
3293 ``version.in''. People creating GDB distributions should update the
3294 contents of this file.
3298 GUD support is now a standard part of the EMACS distribution.
3300 *** Changes in GDB 5.0:
3302 * Improved support for debugging FP programs on x86 targets
3304 Unified and much-improved support for debugging floating-point
3305 programs on all x86 targets. In particular, ``info float'' now
3306 displays the FP registers in the same format on all x86 targets, with
3307 greater level of detail.
3309 * Improvements and bugfixes in hardware-assisted watchpoints
3311 It is now possible to watch array elements, struct members, and
3312 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3313 on x86 targets no longer erroneously trigger when the address is
3316 * Improvements in the native DJGPP version of GDB
3318 The distribution now includes all the scripts and auxiliary files
3319 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3320 machines ``out of the box''.
3322 The DJGPP version can now debug programs that use signals. It is
3323 possible to catch signals that happened in the debuggee, deliver
3324 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3325 would kill the program being debugged.) Programs that hook hardware
3326 interrupts (keyboard, timer, etc.) can also be debugged.
3328 It is now possible to debug DJGPP programs that redirect their
3329 standard handles or switch them to raw (as opposed to cooked) mode, or
3330 even close them. The command ``run < foo > bar'' works as expected,
3331 and ``info terminal'' reports useful information about the debuggee's
3332 terminal, including raw/cooked mode, redirection, etc.
3334 The DJGPP version now uses termios functions for console I/O, which
3335 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3338 DOS-style file names with drive letters are now fully supported by
3341 It is now possible to debug DJGPP programs that switch their working
3342 directory. It is also possible to rerun the debuggee any number of
3343 times without restarting GDB; thus, you can use the same setup,
3344 breakpoints, etc. for many debugging sessions.
3346 * New native configurations
3348 ARM GNU/Linux arm*-*-linux*
3349 PowerPC GNU/Linux powerpc-*-linux*
3353 Motorola MCore mcore-*-*
3354 x86 VxWorks i[3456]86-*-vxworks*
3355 PowerPC VxWorks powerpc-*-vxworks*
3356 TI TMS320C80 tic80-*-*
3358 * OBSOLETE configurations
3360 Altos 3068 m68*-altos-*
3361 Convex c1-*-*, c2-*-*
3363 ARM RISCix arm-*-* (as host)
3366 Configurations that have been declared obsolete will be commented out,
3367 but the code will be left in place. If there is no activity to revive
3368 these configurations before the next release of GDB, the sources will
3369 be permanently REMOVED.
3371 * Gould support removed
3373 Support for the Gould PowerNode and NP1 has been removed.
3375 * New features for SVR4
3377 On SVR4 native platforms (such as Solaris), if you attach to a process
3378 without first loading a symbol file, GDB will now attempt to locate and
3379 load symbols from the running process's executable file.
3381 * Many C++ enhancements
3383 C++ support has been greatly improved. Overload resolution now works properly
3384 in almost all cases. RTTI support is on the way.
3386 * Remote targets can connect to a sub-program
3388 A popen(3) style serial-device has been added. This device starts a
3389 sub-process (such as a stand-alone simulator) and then communicates
3390 with that. The sub-program to run is specified using the syntax
3391 ``|<program> <args>'' vis:
3393 (gdb) set remotedebug 1
3394 (gdb) target extended-remote |mn10300-elf-sim program-args
3396 * MIPS 64 remote protocol
3398 A long standing bug in the mips64 remote protocol where by GDB
3399 expected certain 32 bit registers (ex SR) to be transfered as 32
3400 instead of 64 bits has been fixed.
3402 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3403 added to provide backward compatibility with older versions of GDB.
3405 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3407 The command ``set remotebinarydownload'' command has been replaced by
3408 ``set remote X-packet''. Other commands in ``set remote'' family
3409 include ``set remote P-packet''.
3411 * Breakpoint commands accept ranges.
3413 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3414 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3415 ``tracepoint passcount'' also accepts a range of tracepoints.
3417 * ``apropos'' command added.
3419 The ``apropos'' command searches through command names and
3420 documentation strings, printing out matches, making it much easier to
3421 try to find a command that does what you are looking for.
3425 A new machine oriented interface (MI) has been added to GDB. This
3426 interface is designed for debug environments running GDB as a separate
3427 process. This is part of the long term libGDB project. See the
3428 "GDB/MI" chapter of the GDB manual for further information. It can be
3429 enabled by configuring with:
3431 .../configure --enable-gdbmi
3433 *** Changes in GDB-4.18:
3435 * New native configurations
3437 HP-UX 10.20 hppa*-*-hpux10.20
3438 HP-UX 11.x hppa*-*-hpux11.0*
3439 M68K GNU/Linux m68*-*-linux*
3443 Fujitsu FR30 fr30-*-elf*
3444 Intel StrongARM strongarm-*-*
3445 Mitsubishi D30V d30v-*-*
3447 * OBSOLETE configurations
3449 Gould PowerNode, NP1 np1-*-*, pn-*-*
3451 Configurations that have been declared obsolete will be commented out,
3452 but the code will be left in place. If there is no activity to revive
3453 these configurations before the next release of GDB, the sources will
3454 be permanently REMOVED.
3458 As a compatibility experiment, GDB's source files buildsym.h and
3459 buildsym.c have been converted to pure standard C, no longer
3460 containing any K&R compatibility code. We believe that all systems in
3461 use today either come with a standard C compiler, or have a GCC port
3462 available. If this is not true, please report the affected
3463 configuration to bug-gdb@gnu.org immediately. See the README file for
3464 information about getting a standard C compiler if you don't have one
3469 GDB now uses readline 2.2.
3471 * set extension-language
3473 You can now control the mapping between filename extensions and source
3474 languages by using the `set extension-language' command. For instance,
3475 you can ask GDB to treat .c files as C++ by saying
3476 set extension-language .c c++
3477 The command `info extensions' lists all of the recognized extensions
3478 and their associated languages.
3480 * Setting processor type for PowerPC and RS/6000
3482 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3483 you can use the `set processor' command to specify what variant of the
3484 PowerPC family you are debugging. The command
3488 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3489 following PowerPC and RS6000 variants:
3491 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3492 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3494 403GC IBM PowerPC 403GC
3495 505 Motorola PowerPC 505
3496 860 Motorola PowerPC 860 or 850
3497 601 Motorola PowerPC 601
3498 602 Motorola PowerPC 602
3499 603 Motorola/IBM PowerPC 603 or 603e
3500 604 Motorola PowerPC 604 or 604e
3501 750 Motorola/IBM PowerPC 750 or 750
3503 At the moment, this command just tells GDB what to name the
3504 special-purpose processor registers. Since almost all the affected
3505 registers are inaccessible to user-level programs, this command is
3506 only useful for remote debugging in its present form.
3510 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3511 more extensive support for HP-UX. Added features include shared
3512 library support, kernel threads and hardware watchpoints for 11.00,
3513 support for HP's ANSI C and C++ compilers, and a compatibility mode
3514 for xdb and dbx commands.
3518 HP's donation includes the new concept of catchpoints, which is a
3519 generalization of the old catch command. On HP-UX, it is now possible
3520 to catch exec, fork, and vfork, as well as library loading.
3522 This means that the existing catch command has changed; its first
3523 argument now specifies the type of catch to be set up. See the
3524 output of "help catch" for a list of catchpoint types.
3526 * Debugging across forks
3528 On HP-UX, you can choose which process to debug when a fork() happens
3533 HP has donated a curses-based terminal user interface (TUI). To get
3534 it, build with --enable-tui. Although this can be enabled for any
3535 configuration, at present it only works for native HP debugging.
3537 * GDB remote protocol additions
3539 A new protocol packet 'X' that writes binary data is now available.
3540 Default behavior is to try 'X', then drop back to 'M' if the stub
3541 fails to respond. The settable variable `remotebinarydownload'
3542 allows explicit control over the use of 'X'.
3544 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3545 full 64-bit address. The command
3547 set remoteaddresssize 32
3549 can be used to revert to the old behaviour. For existing remote stubs
3550 the change should not be noticed, as the additional address information
3553 In order to assist in debugging stubs, you may use the maintenance
3554 command `packet' to send any text string to the stub. For instance,
3556 maint packet heythere
3558 sends the packet "$heythere#<checksum>". Note that it is very easy to
3559 disrupt a debugging session by sending the wrong packet at the wrong
3562 The compare-sections command allows you to compare section data on the
3563 target to what is in the executable file without uploading or
3564 downloading, by comparing CRC checksums.
3566 * Tracing can collect general expressions
3568 You may now collect general expressions at tracepoints. This requires
3569 further additions to the target-side stub; see tracepoint.c and
3570 doc/agentexpr.texi for further details.
3572 * mask-address variable for Mips
3574 For Mips targets, you may control the zeroing of the upper 32 bits of
3575 a 64-bit address by entering `set mask-address on'. This is mainly
3576 of interest to users of embedded R4xxx and R5xxx processors.
3578 * Higher serial baud rates
3580 GDB's serial code now allows you to specify baud rates 57600, 115200,
3581 230400, and 460800 baud. (Note that your host system may not be able
3582 to achieve all of these rates.)
3586 The i960 configuration now includes an initial implementation of a
3587 builtin simulator, contributed by Jim Wilson.
3590 *** Changes in GDB-4.17:
3592 * New native configurations
3594 Alpha GNU/Linux alpha*-*-linux*
3595 Unixware 2.x i[3456]86-unixware2*
3596 Irix 6.x mips*-sgi-irix6*
3597 PowerPC GNU/Linux powerpc-*-linux*
3598 PowerPC Solaris powerpcle-*-solaris*
3599 Sparc GNU/Linux sparc-*-linux*
3600 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3604 Argonaut Risc Chip (ARC) arc-*-*
3605 Hitachi H8/300S h8300*-*-*
3606 Matsushita MN10200 w/simulator mn10200-*-*
3607 Matsushita MN10300 w/simulator mn10300-*-*
3608 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3609 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3610 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3611 Mitsubishi D10V w/simulator d10v-*-*
3612 Mitsubishi M32R/D w/simulator m32r-*-elf*
3613 Tsqware Sparclet sparclet-*-*
3614 NEC V850 w/simulator v850-*-*
3616 * New debugging protocols
3618 ARM with RDI protocol arm*-*-*
3619 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3620 DDB and LSI variants of PMON protocol mips*-*-*
3621 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3622 PowerPC with SDS protocol powerpc{,le}-*-eabi
3623 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3627 All configurations can now understand and use the DWARF 2 debugging
3628 format. The choice is automatic, if the symbol file contains DWARF 2
3633 GDB now includes basic Java language support. This support is
3634 only useful with Java compilers that produce native machine code.
3636 * solib-absolute-prefix and solib-search-path
3638 For SunOS and SVR4 shared libraries, you may now set the prefix for
3639 loading absolute shared library symbol files, and the search path for
3640 locating non-absolute shared library symbol files.
3642 * Live range splitting
3644 GDB can now effectively debug code for which GCC has performed live
3645 range splitting as part of its optimization. See gdb/doc/LRS for
3646 more details on the expected format of the stabs information.
3650 GDB's support for the GNU Hurd, including thread debugging, has been
3651 updated to work with current versions of the Hurd.
3655 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3656 instruction set. ARM GDB automatically detects when Thumb
3657 instructions are in use, and adjusts disassembly and backtracing
3662 GDB's MIPS target configurations now handle the MIP16 16-bit
3667 GDB now includes support for overlays; if an executable has been
3668 linked such that multiple sections are based at the same address, GDB
3669 will decide which section to use for symbolic info. You can choose to
3670 control the decision manually, using overlay commands, or implement
3671 additional target-side support and use "overlay load-target" to bring
3672 in the overlay mapping. Do "help overlay" for more detail.
3676 The command "info symbol <address>" displays information about
3677 the symbol at the specified address.
3681 The standard remote protocol now includes an extension that allows
3682 asynchronous collection and display of trace data. This requires
3683 extensive support in the target-side debugging stub. Tracing mode
3684 includes a new interaction mode in GDB and new commands: see the
3685 file tracepoint.c for more details.
3689 Configurations for embedded MIPS now include a simulator contributed
3690 by Cygnus Solutions. The simulator supports the instruction sets
3691 of most MIPS variants.
3695 Sparc configurations may now include the ERC32 simulator contributed
3696 by the European Space Agency. The simulator is not built into
3697 Sparc targets by default; configure with --enable-sim to include it.
3701 For target configurations that may include multiple variants of a
3702 basic architecture (such as MIPS and SH), you may now set the
3703 architecture explicitly. "set arch" sets, "info arch" lists
3704 the possible architectures.
3706 *** Changes in GDB-4.16:
3708 * New native configurations
3710 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3711 M68K NetBSD m68k-*-netbsd*
3712 PowerPC AIX 4.x powerpc-*-aix*
3713 PowerPC MacOS powerpc-*-macos*
3714 PowerPC Windows NT powerpcle-*-cygwin32
3715 RS/6000 AIX 4.x rs6000-*-aix4*
3719 ARM with RDP protocol arm-*-*
3720 I960 with MON960 i960-*-coff
3721 MIPS VxWorks mips*-*-vxworks*
3722 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3723 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3725 Matra Sparclet sparclet-*-*
3729 The powerpc-eabi configuration now includes the PSIM simulator,
3730 contributed by Andrew Cagney, with assistance from Mike Meissner.
3731 PSIM is a very elaborate model of the PowerPC, including not only
3732 basic instruction set execution, but also details of execution unit
3733 performance and I/O hardware. See sim/ppc/README for more details.
3737 GDB now works with Solaris 2.5.
3739 * Windows 95/NT native
3741 GDB will now work as a native debugger on Windows 95 and Windows NT.
3742 To build it from source, you must use the "gnu-win32" environment,
3743 which uses a DLL to emulate enough of Unix to run the GNU tools.
3744 Further information, binaries, and sources are available at
3745 ftp.cygnus.com, under pub/gnu-win32.
3747 * dont-repeat command
3749 If a user-defined command includes the command `dont-repeat', then the
3750 command will not be repeated if the user just types return. This is
3751 useful if the command is time-consuming to run, so that accidental
3752 extra keystrokes don't run the same command many times.
3754 * Send break instead of ^C
3756 The standard remote protocol now includes an option to send a break
3757 rather than a ^C to the target in order to interrupt it. By default,
3758 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3760 * Remote protocol timeout
3762 The standard remote protocol includes a new variable `remotetimeout'
3763 that allows you to set the number of seconds before GDB gives up trying
3764 to read from the target. The default value is 2.
3766 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3768 By default GDB will automatically keep track of objects as they are
3769 loaded and unloaded by the dynamic linker. By using the command `set
3770 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3771 when shared library events occur, thus allowing you to set breakpoints
3772 in shared libraries which are explicitly loaded by the inferior.
3774 Note this feature does not work on hpux8. On hpux9 you must link
3775 /usr/lib/end.o into your program. This feature should work
3776 automatically on hpux10.
3778 * Irix 5.x hardware watchpoint support
3780 Irix 5 configurations now support the use of hardware watchpoints.
3782 * Mips protocol "SYN garbage limit"
3784 When debugging a Mips target using the `target mips' protocol, you
3785 may set the number of characters that GDB will ignore by setting
3786 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3787 every character. The default value is 1050.
3789 * Recording and replaying remote debug sessions
3791 If you set `remotelogfile' to the name of a file, gdb will write to it
3792 a recording of a remote debug session. This recording may then be
3793 replayed back to gdb using "gdbreplay". See gdbserver/README for
3794 details. This is useful when you have a problem with GDB while doing
3795 remote debugging; you can make a recording of the session and send it
3796 to someone else, who can then recreate the problem.
3798 * Speedups for remote debugging
3800 GDB includes speedups for downloading and stepping MIPS systems using
3801 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3802 and more efficient S-record downloading.
3804 * Memory use reductions and statistics collection
3806 GDB now uses less memory and reports statistics about memory usage.
3807 Try the `maint print statistics' command, for example.
3809 *** Changes in GDB-4.15:
3811 * Psymtabs for XCOFF
3813 The symbol reader for AIX GDB now uses partial symbol tables. This
3814 can greatly improve startup time, especially for large executables.
3816 * Remote targets use caching
3818 Remote targets now use a data cache to speed up communication with the
3819 remote side. The data cache could lead to incorrect results because
3820 it doesn't know about volatile variables, thus making it impossible to
3821 debug targets which use memory mapped I/O devices. `set remotecache
3822 off' turns the the data cache off.
3824 * Remote targets may have threads
3826 The standard remote protocol now includes support for multiple threads
3827 in the target system, using new protocol commands 'H' and 'T'. See
3828 gdb/remote.c for details.
3832 If GDB is configured with `--enable-netrom', then it will include
3833 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3834 acts as though it is a bank of ROM on the target board, but you can
3835 write into it over the network. GDB's support consists only of
3836 support for fast loading into the emulated ROM; to debug, you must use
3837 another protocol, such as standard remote protocol. The usual
3838 sequence is something like
3840 target nrom <netrom-hostname>
3842 target remote <netrom-hostname>:1235
3846 GDB now includes support for the Apple Macintosh, as a host only. It
3847 may be run as either an MPW tool or as a standalone application, and
3848 it can debug through the serial port. All the usual GDB commands are
3849 available, but to the target command, you must supply "serial" as the
3850 device type instead of "/dev/ttyXX". See mpw-README in the main
3851 directory for more information on how to build. The MPW configuration
3852 scripts */mpw-config.in support only a few targets, and only the
3853 mips-idt-ecoff target has been tested.
3857 GDB configuration now uses autoconf. This is not user-visible,
3858 but does simplify configuration and building.
3862 GDB now supports hpux10.
3864 *** Changes in GDB-4.14:
3866 * New native configurations
3868 x86 FreeBSD i[345]86-*-freebsd
3869 x86 NetBSD i[345]86-*-netbsd
3870 NS32k NetBSD ns32k-*-netbsd
3871 Sparc NetBSD sparc-*-netbsd
3875 A29K VxWorks a29k-*-vxworks
3876 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3877 CPU32 EST-300 emulator m68*-*-est*
3878 PowerPC ELF powerpc-*-elf
3881 * Alpha OSF/1 support for procfs
3883 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3884 possible to attach to running processes. As the mounting of the /proc
3885 filesystem is optional on the Alpha, GDB automatically determines
3886 the availability of /proc during startup. This can lead to problems
3887 if /proc is unmounted after GDB has been started.
3889 * Arguments to user-defined commands
3891 User commands may accept up to 10 arguments separated by whitespace.
3892 Arguments are accessed within the user command via $arg0..$arg9. A
3895 print $arg0 + $arg1 + $arg2
3897 To execute the command use:
3900 Defines the command "adder" which prints the sum of its three arguments.
3901 Note the arguments are text substitutions, so they may reference variables,
3902 use complex expressions, or even perform inferior function calls.
3904 * New `if' and `while' commands
3906 This makes it possible to write more sophisticated user-defined
3907 commands. Both commands take a single argument, which is the
3908 expression to evaluate, and must be followed by the commands to
3909 execute, one per line, if the expression is nonzero, the list being
3910 terminated by the word `end'. The `if' command list may include an
3911 `else' word, which causes the following commands to be executed only
3912 if the expression is zero.
3914 * Fortran source language mode
3916 GDB now includes partial support for Fortran 77. It will recognize
3917 Fortran programs and can evaluate a subset of Fortran expressions, but
3918 variables and functions may not be handled correctly. GDB will work
3919 with G77, but does not yet know much about symbols emitted by other
3922 * Better HPUX support
3924 Most debugging facilities now work on dynamic executables for HPPAs
3925 running hpux9 or later. You can attach to running dynamically linked
3926 processes, but by default the dynamic libraries will be read-only, so
3927 for instance you won't be able to put breakpoints in them. To change
3928 that behavior do the following before running the program:
3934 This will cause the libraries to be mapped private and read-write.
3935 To revert to the normal behavior, do this:
3941 You cannot set breakpoints or examine data in the library until after
3942 the library is loaded if the function/data symbols do not have
3945 GDB can now also read debug symbols produced by the HP C compiler on
3946 HPPAs (sorry, no C++, Fortran or 68k support).
3948 * Target byte order now dynamically selectable
3950 You can choose which byte order to use with a target system, via the
3951 commands "set endian big" and "set endian little", and you can see the
3952 current setting by using "show endian". You can also give the command
3953 "set endian auto", in which case GDB will use the byte order
3954 associated with the executable. Currently, only embedded MIPS
3955 configurations support dynamic selection of target byte order.
3957 * New DOS host serial code
3959 This version uses DPMI interrupts to handle buffered I/O, so you
3960 no longer need to run asynctsr when debugging boards connected to
3963 *** Changes in GDB-4.13:
3965 * New "complete" command
3967 This lists all the possible completions for the rest of the line, if it
3968 were to be given as a command itself. This is intended for use by emacs.
3970 * Trailing space optional in prompt
3972 "set prompt" no longer adds a space for you after the prompt you set. This
3973 allows you to set a prompt which ends in a space or one that does not.
3975 * Breakpoint hit counts
3977 "info break" now displays a count of the number of times the breakpoint
3978 has been hit. This is especially useful in conjunction with "ignore"; you
3979 can ignore a large number of breakpoint hits, look at the breakpoint info
3980 to see how many times the breakpoint was hit, then run again, ignoring one
3981 less than that number, and this will get you quickly to the last hit of
3984 * Ability to stop printing at NULL character
3986 "set print null-stop" will cause GDB to stop printing the characters of
3987 an array when the first NULL is encountered. This is useful when large
3988 arrays actually contain only short strings.
3990 * Shared library breakpoints
3992 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
3993 breakpoints in shared libraries before the executable is run.
3995 * Hardware watchpoints
3997 There is a new hardware breakpoint for the watch command for sparclite
3998 targets. See gdb/sparclite/hw_breakpoint.note.
4000 Hardware watchpoints are also now supported under GNU/Linux.
4004 Annotations have been added. These are for use with graphical interfaces,
4005 and are still experimental. Currently only gdba.el uses these.
4007 * Improved Irix 5 support
4009 GDB now works properly with Irix 5.2.
4011 * Improved HPPA support
4013 GDB now works properly with the latest GCC and GAS.
4015 * New native configurations
4017 Sequent PTX4 i[34]86-sequent-ptx4
4018 HPPA running OSF/1 hppa*-*-osf*
4019 Atari TT running SVR4 m68*-*-sysv4*
4020 RS/6000 LynxOS rs6000-*-lynxos*
4024 OS/9000 i[34]86-*-os9k
4025 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4028 * Hitachi SH7000 and E7000-PC ICE support
4030 There is now support for communicating with the Hitachi E7000-PC ICE.
4031 This is available automatically when GDB is configured for the SH.
4035 As usual, a variety of small fixes and improvements, both generic
4036 and configuration-specific. See the ChangeLog for more detail.
4038 *** Changes in GDB-4.12:
4040 * Irix 5 is now supported
4044 GDB-4.12 on the HPPA has a number of changes which make it unable
4045 to debug the output from the currently released versions of GCC and
4046 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4047 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4048 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4051 *** Changes in GDB-4.11:
4053 * User visible changes:
4057 The "set remotedebug" option is now consistent between the mips remote
4058 target, remote targets using the gdb-specific protocol, UDI (AMD's
4059 debug protocol for the 29k) and the 88k bug monitor. It is now an
4060 integer specifying a debug level (normally 0 or 1, but 2 means more
4061 debugging info for the mips target).
4063 * DEC Alpha native support
4065 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4066 debug info, but GDB works fairly well with the DEC compiler and should
4067 work with a future GCC release. See the README file for a few
4068 Alpha-specific notes.
4070 * Preliminary thread implementation
4072 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4074 * LynxOS native and target support for 386
4076 This release has been hosted on LynxOS 2.2, and also can be configured
4077 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4080 * Improvements in C++ mangling/demangling.
4082 This release has much better g++ debugging, specifically in name
4083 mangling/demangling, virtual function calls, print virtual table,
4084 call methods, ...etc.
4086 *** Changes in GDB-4.10:
4088 * User visible changes:
4090 Remote debugging using the GDB-specific (`target remote') protocol now
4091 supports the `load' command. This is only useful if you have some
4092 other way of getting the stub to the target system, and you can put it
4093 somewhere in memory where it won't get clobbered by the download.
4095 Filename completion now works.
4097 When run under emacs mode, the "info line" command now causes the
4098 arrow to point to the line specified. Also, "info line" prints
4099 addresses in symbolic form (as well as hex).
4101 All vxworks based targets now support a user settable option, called
4102 vxworks-timeout. This option represents the number of seconds gdb
4103 should wait for responses to rpc's. You might want to use this if
4104 your vxworks target is, perhaps, a slow software simulator or happens
4105 to be on the far side of a thin network line.
4109 This release contains support for using a DEC alpha as a GDB host for
4110 cross debugging. Native alpha debugging is not supported yet.
4113 *** Changes in GDB-4.9:
4117 This is the first GDB release which is accompanied by a matching testsuite.
4118 The testsuite requires installation of dejagnu, which should be available
4119 via ftp from most sites that carry GNU software.
4123 'Cfront' style demangling has had its name changed to 'ARM' style, to
4124 emphasize that it was written from the specifications in the C++ Annotated
4125 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4126 disclaimers, it still generated too much confusion with users attempting to
4127 use gdb with AT&T cfront.
4131 GDB now uses a standard remote interface to a simulator library.
4132 So far, the library contains simulators for the Zilog Z8001/2, the
4133 Hitachi H8/300, H8/500 and Super-H.
4135 * New targets supported
4137 H8/300 simulator h8300-hitachi-hms or h8300hms
4138 H8/500 simulator h8500-hitachi-hms or h8500hms
4139 SH simulator sh-hitachi-hms or sh
4140 Z8000 simulator z8k-zilog-none or z8ksim
4141 IDT MIPS board over serial line mips-idt-ecoff
4143 Cross-debugging to GO32 targets is supported. It requires a custom
4144 version of the i386-stub.c module which is integrated with the
4145 GO32 memory extender.
4147 * New remote protocols
4149 MIPS remote debugging protocol.
4151 * New source languages supported
4153 This version includes preliminary support for Chill, a Pascal like language
4154 used by telecommunications companies. Chill support is also being integrated
4155 into the GNU compiler, but we don't know when it will be publically available.
4158 *** Changes in GDB-4.8:
4160 * HP Precision Architecture supported
4162 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4163 version of this support was available as a set of patches from the
4164 University of Utah. GDB does not support debugging of programs
4165 compiled with the HP compiler, because HP will not document their file
4166 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4167 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4169 Many problems in the preliminary version have been fixed.
4171 * Faster and better demangling
4173 We have improved template demangling and fixed numerous bugs in the GNU style
4174 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4175 character types (wchar_t) are now supported. Demangling of each symbol is now
4176 only done once, and is cached when the symbol table for a file is read in.
4177 This results in a small increase in memory usage for C programs, a moderate
4178 increase in memory usage for C++ programs, and a fantastic speedup in
4181 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4182 from the specifications in the Annotated Reference Manual, which AT&T's
4183 compiler does not actually implement.
4185 * G++ multiple inheritance compiler problem
4187 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4188 inheritance lattices was reworked to properly discover ambiguities. We
4189 recently found an example which causes this new algorithm to fail in a
4190 very subtle way, producing bad debug information for those classes.
4191 The file 'gcc.patch' (in this directory) can be applied to gcc to
4192 circumvent the problem. A future GCC release will contain a complete
4195 The previous G++ debug info problem (mentioned below for the gdb-4.7
4196 release) is fixed in gcc version 2.3.2.
4198 * Improved configure script
4200 The `configure' script will now attempt to guess your system type if
4201 you don't supply a host system type. The old scheme of supplying a
4202 host system triplet is preferable over using this. All the magic is
4203 done in the new `config.guess' script. Examine it for details.
4205 We have also brought our configure script much more in line with the FSF's
4206 version. It now supports the --with-xxx options. In particular,
4207 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4208 The resulting GDB will not be able to read arbitrary object file formats --
4209 only the format ``expected'' to be used on the configured target system.
4210 We hope to make this the default in a future release.
4212 * Documentation improvements
4214 There's new internal documentation on how to modify GDB, and how to
4215 produce clean changes to the code. We implore people to read it
4216 before submitting changes.
4218 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4219 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4220 `info' files are also provided. To build `info' files from scratch,
4221 you will need the latest `makeinfo' release, which will be available in
4222 a future texinfo-X.Y release.
4224 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4225 We're not sure exactly which versions have this problem, but it has
4226 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4227 or better. If that isn't possible, there is a patch in
4228 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4229 around this problem.
4233 GDB now supports array constants that can be used in expressions typed in by
4234 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4235 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4238 The new directory `gdb/sparclite' contains a program that demonstrates
4239 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4241 * New native hosts supported
4243 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4244 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4246 * New targets supported
4248 AMD 29k family via UDI a29k-amd-udi or udi29k
4250 * New file formats supported
4252 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4253 HPUX core files, and SCO 3.2v2 core files.
4257 Attaching to processes now works again; thanks for the many bug reports.
4259 We have also stomped on a bunch of core dumps caused by
4260 printf_filtered("%s") problems.
4262 We eliminated a copyright problem on the rpc and ptrace header files
4263 for VxWorks, which was discovered at the last minute during the 4.7
4264 release. You should now be able to build a VxWorks GDB.
4266 You can now interrupt gdb while an attached process is running. This
4267 will cause the attached process to stop, and give control back to GDB.
4269 We fixed problems caused by using too many file descriptors
4270 for reading symbols from object files and libraries. This was
4271 especially a problem for programs that used many (~100) shared
4274 The `step' command now only enters a subroutine if there is line number
4275 information for the subroutine. Otherwise it acts like the `next'
4276 command. Previously, `step' would enter subroutines if there was
4277 any debugging information about the routine. This avoids problems
4278 when using `cc -g1' on MIPS machines.
4280 * Internal improvements
4282 GDB's internal interfaces have been improved to make it easier to support
4283 debugging of multiple languages in the future.
4285 GDB now uses a common structure for symbol information internally.
4286 Minimal symbols (derived from linkage symbols in object files), partial
4287 symbols (from a quick scan of debug information), and full symbols
4288 contain a common subset of information, making it easier to write
4289 shared code that handles any of them.
4291 * New command line options
4293 We now accept --silent as an alias for --quiet.
4297 The memory-mapped-malloc library is now licensed under the GNU Library
4298 General Public License.
4300 *** Changes in GDB-4.7:
4302 * Host/native/target split
4304 GDB has had some major internal surgery to untangle the support for
4305 hosts and remote targets. Now, when you configure GDB for a remote
4306 target, it will no longer load in all of the support for debugging
4307 local programs on the host. When fully completed and tested, this will
4308 ensure that arbitrary host/target combinations are possible.
4310 The primary conceptual shift is to separate the non-portable code in
4311 GDB into three categories. Host specific code is required any time GDB
4312 is compiled on that host, regardless of the target. Target specific
4313 code relates to the peculiarities of the target, but can be compiled on
4314 any host. Native specific code is everything else: it can only be
4315 built when the host and target are the same system. Child process
4316 handling and core file support are two common `native' examples.
4318 GDB's use of /proc for controlling Unix child processes is now cleaner.
4319 It has been split out into a single module under the `target_ops' vector,
4320 plus two native-dependent functions for each system that uses /proc.
4322 * New hosts supported
4324 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4325 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4326 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4328 * New targets supported
4330 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4331 68030 and CPU32 m68030-*-*, m68332-*-*
4333 * New native hosts supported
4335 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4336 (386bsd is not well tested yet)
4337 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4339 * New file formats supported
4341 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4342 supports reading of `a.out.adobe' object files, which are an a.out
4343 format extended with minimal information about multiple sections.
4347 `show copying' is the same as the old `info copying'.
4348 `show warranty' is the same as `info warrantee'.
4349 These were renamed for consistency. The old commands continue to work.
4351 `info handle' is a new alias for `info signals'.
4353 You can now define pre-command hooks, which attach arbitrary command
4354 scripts to any command. The commands in the hook will be executed
4355 prior to the user's command. You can also create a hook which will be
4356 executed whenever the program stops. See gdb.texinfo.
4360 We now deal with Cfront style name mangling, and can even extract type
4361 info from mangled symbols. GDB can automatically figure out which
4362 symbol mangling style your C++ compiler uses.
4364 Calling of methods and virtual functions has been improved as well.
4368 The crash that occured when debugging Sun Ansi-C compiled binaries is
4369 fixed. This was due to mishandling of the extra N_SO stabs output
4372 We also finally got Ultrix 4.2 running in house, and fixed core file
4373 support, with help from a dozen people on the net.
4375 John M. Farrell discovered that the reason that single-stepping was so
4376 slow on all of the Mips based platforms (primarily SGI and DEC) was
4377 that we were trying to demangle and lookup a symbol used for internal
4378 purposes on every instruction that was being stepped through. Changing
4379 the name of that symbol so that it couldn't be mistaken for a C++
4380 mangled symbol sped things up a great deal.
4382 Rich Pixley sped up symbol lookups in general by getting much smarter
4383 about when C++ symbol mangling is necessary. This should make symbol
4384 completion (TAB on the command line) much faster. It's not as fast as
4385 we'd like, but it's significantly faster than gdb-4.6.
4389 A new user controllable variable 'call_scratch_address' can
4390 specify the location of a scratch area to be used when GDB
4391 calls a function in the target. This is necessary because the
4392 usual method of putting the scratch area on the stack does not work
4393 in systems that have separate instruction and data spaces.
4395 We integrated changes to support the 29k UDI (Universal Debugger
4396 Interface), but discovered at the last minute that we didn't have all
4397 of the appropriate copyright paperwork. We are working with AMD to
4398 resolve this, and hope to have it available soon.
4402 We have sped up the remote serial line protocol, especially for targets
4403 with lots of registers. It now supports a new `expedited status' ('T')
4404 message which can be used in place of the existing 'S' status message.
4405 This allows the remote stub to send only the registers that GDB
4406 needs to make a quick decision about single-stepping or conditional
4407 breakpoints, eliminating the need to fetch the entire register set for
4408 each instruction being stepped through.
4410 The GDB remote serial protocol now implements a write-through cache for
4411 registers, only re-reading the registers if the target has run.
4413 There is also a new remote serial stub for SPARC processors. You can
4414 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4415 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4416 processor with a serial port.
4420 Configure.in files have become much easier to read and modify. A new
4421 `table driven' format makes it more obvious what configurations are
4422 supported, and what files each one uses.
4426 There is a new opcodes library which will eventually contain all of the
4427 disassembly routines and opcode tables. At present, it only contains
4428 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4429 disassembler (binutils/objdump) to share these routines.
4431 The libiberty library is now copylefted under the GNU Library General
4432 Public License. This allows more liberal use, and was done so libg++
4433 can use it. This makes no difference to GDB, since the Library License
4434 grants all the rights from the General Public License.
4438 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4439 reference to the stabs symbol info used by the debugger. It is (as far
4440 as we know) the only published document on this fascinating topic. We
4441 encourage you to read it, compare it to the stabs information on your
4442 system, and send improvements on the document in general (to
4443 bug-gdb@prep.ai.mit.edu).
4445 And, of course, many bugs have been fixed.
4448 *** Changes in GDB-4.6:
4450 * Better support for C++ function names
4452 GDB now accepts as input the "demangled form" of C++ overloaded function
4453 names and member function names, and can do command completion on such names
4454 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4455 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4456 Make use of command completion, it is your friend.
4458 GDB also now accepts a variety of C++ mangled symbol formats. They are
4459 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4460 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4461 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4462 for the list of formats.
4464 * G++ symbol mangling problem
4466 Recent versions of gcc have a bug in how they emit debugging information for
4467 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4468 directory) can be applied to gcc to fix the problem. Alternatively, if you
4469 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4470 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4471 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4474 * New 'maintenance' command
4476 All of the commands related to hacking GDB internals have been moved out of
4477 the main command set, and now live behind the 'maintenance' command. This
4478 can also be abbreviated as 'mt'. The following changes were made:
4480 dump-me -> maintenance dump-me
4481 info all-breakpoints -> maintenance info breakpoints
4482 printmsyms -> maintenance print msyms
4483 printobjfiles -> maintenance print objfiles
4484 printpsyms -> maintenance print psymbols
4485 printsyms -> maintenance print symbols
4487 The following commands are new:
4489 maintenance demangle Call internal GDB demangler routine to
4490 demangle a C++ link name and prints the result.
4491 maintenance print type Print a type chain for a given symbol
4493 * Change to .gdbinit file processing
4495 We now read the $HOME/.gdbinit file before processing the argv arguments
4496 (e.g. reading symbol files or core files). This allows global parameters to
4497 be set, which will apply during the symbol reading. The ./.gdbinit is still
4498 read after argv processing.
4500 * New hosts supported
4502 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4504 GNU/Linux support i386-unknown-linux or linux
4506 We are also including code to support the HP/PA running BSD and HPUX. This
4507 is almost guaranteed not to work, as we didn't have time to test or build it
4508 for this release. We are including it so that the more adventurous (or
4509 masochistic) of you can play with it. We also had major problems with the
4510 fact that the compiler that we got from HP doesn't support the -g option.
4513 * New targets supported
4515 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4517 * More smarts about finding #include files
4519 GDB now remembers the compilation directory for all include files, and for
4520 all files from which C is generated (like yacc and lex sources). This
4521 greatly improves GDB's ability to find yacc/lex sources, and include files,
4522 especially if you are debugging your program from a directory different from
4523 the one that contains your sources.
4525 We also fixed a bug which caused difficulty with listing and setting
4526 breakpoints in include files which contain C code. (In the past, you had to
4527 try twice in order to list an include file that you hadn't looked at before.)
4529 * Interesting infernals change
4531 GDB now deals with arbitrary numbers of sections, where the symbols for each
4532 section must be relocated relative to that section's landing place in the
4533 target's address space. This work was needed to support ELF with embedded
4534 stabs used by Solaris-2.0.
4536 * Bug fixes (of course!)
4538 There have been loads of fixes for the following things:
4539 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4540 i960, stabs, DOS(GO32), procfs, etc...
4542 See the ChangeLog for details.
4544 *** Changes in GDB-4.5:
4546 * New machines supported (host and target)
4548 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4550 SGI Irix-4.x mips-sgi-irix4 or iris4
4552 * New malloc package
4554 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4555 Mmalloc is capable of handling mutiple heaps of memory. It is also
4556 capable of saving a heap to a file, and then mapping it back in later.
4557 This can be used to greatly speedup the startup of GDB by using a
4558 pre-parsed symbol table which lives in a mmalloc managed heap. For
4559 more details, please read mmalloc/mmalloc.texi.
4563 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4564 'help info proc' for details.
4566 * MIPS ecoff symbol table format
4568 The code that reads MIPS symbol table format is now supported on all hosts.
4569 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4572 * File name changes for MS-DOS
4574 Many files in the config directories have been renamed to make it easier to
4575 support GDB on MS-DOSe systems (which have very restrictive file name
4576 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4577 environment) is close to working but has some remaining problems. Note
4578 that debugging of DOS programs is not supported, due to limitations
4579 in the ``operating system'', but it can be used to host cross-debugging.
4581 * Cross byte order fixes
4583 Many fixes have been made to support cross debugging of Sparc and MIPS
4584 targets from hosts whose byte order differs.
4586 * New -mapped and -readnow options
4588 If memory-mapped files are available on your system through the 'mmap'
4589 system call, you can use the -mapped option on the `file' or
4590 `symbol-file' commands to cause GDB to write the symbols from your
4591 program into a reusable file. If the program you are debugging is
4592 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4593 Future GDB debugging sessions will notice the presence of this file,
4594 and will quickly map in symbol information from it, rather than reading
4595 the symbol table from the executable program. Using the '-mapped'
4596 option in a GDB `file' or `symbol-file' command has the same effect as
4597 starting GDB with the '-mapped' command-line option.
4599 You can cause GDB to read the entire symbol table immediately by using
4600 the '-readnow' option with any of the commands that load symbol table
4601 information (or on the GDB command line). This makes the command
4602 slower, but makes future operations faster.
4604 The -mapped and -readnow options are typically combined in order to
4605 build a `fred.syms' file that contains complete symbol information.
4606 A simple GDB invocation to do nothing but build a `.syms' file for future
4609 gdb -batch -nx -mapped -readnow programname
4611 The `.syms' file is specific to the host machine on which GDB is run.
4612 It holds an exact image of GDB's internal symbol table. It cannot be
4613 shared across multiple host platforms.
4615 * longjmp() handling
4617 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4618 siglongjmp() without losing control. This feature has not yet been ported to
4619 all systems. It currently works on many 386 platforms, all MIPS-based
4620 platforms (SGI, DECstation, etc), and Sun3/4.
4624 Preliminary work has been put in to support the new Solaris OS from Sun. At
4625 this time, it can control and debug processes, but it is not capable of
4630 As always, many many bug fixes. The major areas were with g++, and mipsread.
4631 People using the MIPS-based platforms should experience fewer mysterious
4632 crashes and trashed symbol tables.
4634 *** Changes in GDB-4.4:
4636 * New machines supported (host and target)
4638 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4640 BSD Reno on Vax vax-dec-bsd
4641 Ultrix on Vax vax-dec-ultrix
4643 * New machines supported (target)
4645 AMD 29000 embedded, using EBMON a29k-none-none
4649 GDB continues to improve its handling of C++. `References' work better.
4650 The demangler has also been improved, and now deals with symbols mangled as
4651 per the Annotated C++ Reference Guide.
4653 GDB also now handles `stabs' symbol information embedded in MIPS
4654 `ecoff' symbol tables. Since the ecoff format was not easily
4655 extensible to handle new languages such as C++, this appeared to be a
4656 good way to put C++ debugging info into MIPS binaries. This option
4657 will be supported in the GNU C compiler, version 2, when it is
4660 * New features for SVR4
4662 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4663 shared libraries. Debugging dynamically linked programs should present
4664 only minor differences from debugging statically linked programs.
4666 The `info proc' command will print out information about any process
4667 on an SVR4 system (including the one you are debugging). At the moment,
4668 it prints the address mappings of the process.
4670 If you bring up GDB on another SVR4 system, please send mail to
4671 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4673 * Better dynamic linking support in SunOS
4675 Reading symbols from shared libraries which contain debugging symbols
4676 now works properly. However, there remain issues such as automatic
4677 skipping of `transfer vector' code during function calls, which
4678 make it harder to debug code in a shared library, than to debug the
4679 same code linked statically.
4683 GDB is now using the latest `getopt' routines from the FSF. This
4684 version accepts the -- prefix for options with long names. GDB will
4685 continue to accept the old forms (-option and +option) as well.
4686 Various single letter abbreviations for options have been explicity
4687 added to the option table so that they won't get overshadowed in the
4688 future by other options that begin with the same letter.
4692 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4693 Many assorted bugs have been handled. Many more remain to be handled.
4694 See the various ChangeLog files (primarily in gdb and bfd) for details.
4697 *** Changes in GDB-4.3:
4699 * New machines supported (host and target)
4701 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4702 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4703 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4705 * Almost SCO Unix support
4707 We had hoped to support:
4708 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4709 (except for core file support), but we discovered very late in the release
4710 that it has problems with process groups that render gdb unusable. Sorry
4711 about that. I encourage people to fix it and post the fixes.
4713 * Preliminary ELF and DWARF support
4715 GDB can read ELF object files on System V Release 4, and can handle
4716 debugging records for C, in DWARF format, in ELF files. This support
4717 is preliminary. If you bring up GDB on another SVR4 system, please
4718 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4723 GDB now uses the latest `readline' library. One user-visible change
4724 is that two tabs will list possible command completions, which previously
4725 required typing M-? (meta-question mark, or ESC ?).
4729 The `stepi' bug that many of you noticed has been squashed.
4730 Many bugs in C++ have been handled. Many more remain to be handled.
4731 See the various ChangeLog files (primarily in gdb and bfd) for details.
4733 * State of the MIPS world (in case you wondered):
4735 GDB can understand the symbol tables emitted by the compilers
4736 supplied by most vendors of MIPS-based machines, including DEC. These
4737 symbol tables are in a format that essentially nobody else uses.
4739 Some versions of gcc come with an assembler post-processor called
4740 mips-tfile. This program is required if you want to do source-level
4741 debugging of gcc-compiled programs. I believe FSF does not ship
4742 mips-tfile with gcc version 1, but it will eventually come with gcc
4745 Debugging of g++ output remains a problem. g++ version 1.xx does not
4746 really support it at all. (If you're lucky, you should be able to get
4747 line numbers and stack traces to work, but no parameters or local
4748 variables.) With some work it should be possible to improve the
4751 When gcc version 2 is released, you will have somewhat better luck.
4752 However, even then you will get confusing results for inheritance and
4755 We will eventually provide full debugging of g++ output on
4756 DECstations. This will probably involve some kind of stabs-in-ecoff
4757 encapulation, but the details have not been worked out yet.
4760 *** Changes in GDB-4.2:
4762 * Improved configuration
4764 Only one copy of `configure' exists now, and it is not self-modifying.
4765 Porting BFD is simpler.
4769 The `step' and `next' commands now only stop at the first instruction
4770 of a source line. This prevents the multiple stops that used to occur
4771 in switch statements, for-loops, etc. `Step' continues to stop if a
4772 function that has debugging information is called within the line.
4776 Lots of small bugs fixed. More remain.
4778 * New host supported (not target)
4780 Intel 386 PC clone running Mach i386-none-mach
4783 *** Changes in GDB-4.1:
4785 * Multiple source language support
4787 GDB now has internal scaffolding to handle several source languages.
4788 It determines the type of each source file from its filename extension,
4789 and will switch expression parsing and number formatting to match the
4790 language of the function in the currently selected stack frame.
4791 You can also specifically set the language to be used, with
4792 `set language c' or `set language modula-2'.
4796 GDB now has preliminary support for the GNU Modula-2 compiler,
4797 currently under development at the State University of New York at
4798 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4799 continue through the fall of 1991 and into 1992.
4801 Other Modula-2 compilers are currently not supported, and attempting to
4802 debug programs compiled with them will likely result in an error as the
4803 symbol table is read. Feel free to work on it, though!
4805 There are hooks in GDB for strict type checking and range checking,
4806 in the `Modula-2 philosophy', but they do not currently work.
4810 GDB can now write to executable and core files (e.g. patch
4811 a variable's value). You must turn this switch on, specify
4812 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4813 by assigning a new value to a variable. Modifications take
4816 * Automatic SunOS shared library reading
4818 When you run your program, GDB automatically determines where its
4819 shared libraries (if any) have been loaded, and reads their symbols.
4820 The `share' command is no longer needed. This also works when
4821 examining core files.
4825 You can specify the number of lines that the `list' command shows.
4828 * New machines supported (host and target)
4830 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4831 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4832 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4834 * New hosts supported (not targets)
4836 IBM RT/PC: romp-ibm-aix or rtpc
4838 * New targets supported (not hosts)
4840 AMD 29000 embedded with COFF a29k-none-coff
4841 AMD 29000 embedded with a.out a29k-none-aout
4842 Ultracomputer remote kernel debug a29k-nyu-kern
4844 * New remote interfaces
4850 *** Changes in GDB-4.0:
4854 Wide output is wrapped at good places to make the output more readable.
4856 Gdb now supports cross-debugging from a host machine of one type to a
4857 target machine of another type. Communication with the target system
4858 is over serial lines. The ``target'' command handles connecting to the
4859 remote system; the ``load'' command will download a program into the
4860 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4861 also supports debugging of realtime processes running under VxWorks,
4862 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4863 stub on the target system.
4865 New CPUs supported include the AMD 29000 and Intel 960.
4867 GDB now reads object files and symbol tables via a ``binary file''
4868 library, which allows a single copy of GDB to debug programs of multiple
4869 object file types such as a.out and coff.
4871 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4872 refcard.dvi and refcard.ps are available to format it).
4875 * Control-Variable user interface simplified
4877 All variables that control the operation of the debugger can be set
4878 by the ``set'' command, and displayed by the ``show'' command.
4880 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4881 ``Show prompt'' produces the response:
4882 Gdb's prompt is new-gdb=>.
4884 What follows are the NEW set commands. The command ``help set'' will
4885 print a complete list of old and new set commands. ``help set FOO''
4886 will give a longer description of the variable FOO. ``show'' will show
4887 all of the variable descriptions and their current settings.
4889 confirm on/off: Enables warning questions for operations that are
4890 hard to recover from, e.g. rerunning the program while
4891 it is already running. Default is ON.
4893 editing on/off: Enables EMACS style command line editing
4894 of input. Previous lines can be recalled with
4895 control-P, the current line can be edited with control-B,
4896 you can search for commands with control-R, etc.
4899 history filename NAME: NAME is where the gdb command history
4900 will be stored. The default is .gdb_history,
4901 or the value of the environment variable
4904 history size N: The size, in commands, of the command history. The
4905 default is 256, or the value of the environment variable
4908 history save on/off: If this value is set to ON, the history file will
4909 be saved after exiting gdb. If set to OFF, the
4910 file will not be saved. The default is OFF.
4912 history expansion on/off: If this value is set to ON, then csh-like
4913 history expansion will be performed on
4914 command line input. The default is OFF.
4916 radix N: Sets the default radix for input and output. It can be set
4917 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4918 in the current radix, so "set radix 10" is always a no-op.
4920 height N: This integer value is the number of lines on a page. Default
4921 is 24, the current `stty rows'' setting, or the ``li#''
4922 setting from the termcap entry matching the environment
4925 width N: This integer value is the number of characters on a line.
4926 Default is 80, the current `stty cols'' setting, or the ``co#''
4927 setting from the termcap entry matching the environment
4930 Note: ``set screensize'' is obsolete. Use ``set height'' and
4931 ``set width'' instead.
4933 print address on/off: Print memory addresses in various command displays,
4934 such as stack traces and structure values. Gdb looks
4935 more ``symbolic'' if you turn this off; it looks more
4936 ``machine level'' with it on. Default is ON.
4938 print array on/off: Prettyprint arrays. New convenient format! Default
4941 print demangle on/off: Print C++ symbols in "source" form if on,
4944 print asm-demangle on/off: Same, for assembler level printouts
4947 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4950 * Support for Epoch Environment.
4952 The epoch environment is a version of Emacs v18 with windowing. One
4953 new command, ``inspect'', is identical to ``print'', except that if you
4954 are running in the epoch environment, the value is printed in its own
4958 * Support for Shared Libraries
4960 GDB can now debug programs and core files that use SunOS shared libraries.
4961 Symbols from a shared library cannot be referenced
4962 before the shared library has been linked with the program (this
4963 happens after you type ``run'' and before the function main() is entered).
4964 At any time after this linking (including when examining core files
4965 from dynamically linked programs), gdb reads the symbols from each
4966 shared library when you type the ``sharedlibrary'' command.
4967 It can be abbreviated ``share''.
4969 sharedlibrary REGEXP: Load shared object library symbols for files
4970 matching a unix regular expression. No argument
4971 indicates to load symbols for all shared libraries.
4973 info sharedlibrary: Status of loaded shared libraries.
4978 A watchpoint stops execution of a program whenever the value of an
4979 expression changes. Checking for this slows down execution
4980 tremendously whenever you are in the scope of the expression, but is
4981 quite useful for catching tough ``bit-spreader'' or pointer misuse
4982 problems. Some machines such as the 386 have hardware for doing this
4983 more quickly, and future versions of gdb will use this hardware.
4985 watch EXP: Set a watchpoint (breakpoint) for an expression.
4987 info watchpoints: Information about your watchpoints.
4989 delete N: Deletes watchpoint number N (same as breakpoints).
4990 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4991 enable N: Re-enables watchpoint number N (same as breakpoints).
4994 * C++ multiple inheritance
4996 When used with a GCC version 2 compiler, GDB supports multiple inheritance
4999 * C++ exception handling
5001 Gdb now supports limited C++ exception handling. Besides the existing
5002 ability to breakpoint on an exception handler, gdb can breakpoint on
5003 the raising of an exception (before the stack is peeled back to the
5006 catch FOO: If there is a FOO exception handler in the dynamic scope,
5007 set a breakpoint to catch exceptions which may be raised there.
5008 Multiple exceptions (``catch foo bar baz'') may be caught.
5010 info catch: Lists all exceptions which may be caught in the
5011 current stack frame.
5014 * Minor command changes
5016 The command ``call func (arg, arg, ...)'' now acts like the print
5017 command, except it does not print or save a value if the function's result
5018 is void. This is similar to dbx usage.
5020 The ``up'' and ``down'' commands now always print the frame they end up
5021 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5022 frames without printing.
5024 * New directory command
5026 'dir' now adds directories to the FRONT of the source search path.
5027 The path starts off empty. Source files that contain debug information
5028 about the directory in which they were compiled can be found even
5029 with an empty path; Sun CC and GCC include this information. If GDB can't
5030 find your source file in the current directory, type "dir .".
5032 * Configuring GDB for compilation
5034 For normal use, type ``./configure host''. See README or gdb.texinfo
5037 GDB now handles cross debugging. If you are remotely debugging between
5038 two different machines, type ``./configure host -target=targ''.
5039 Host is the machine where GDB will run; targ is the machine
5040 where the program that you are debugging will run.