1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
6 * GDB now supports access to MIPS DSP registers on Linux targets.
8 * GDB now supports debugging microMIPS binaries.
10 * The "info os" command on GNU/Linux can now display information on
11 several new classes of objects managed by the operating system:
12 "info os procgroups" lists process groups
13 "info os files" lists file descriptors
14 "info os sockets" lists internet-domain sockets
15 "info os shm" lists shared-memory regions
16 "info os semaphores" lists semaphores
17 "info os msg" lists message queues
18 "info os modules" lists loaded kernel modules
20 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
21 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
22 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
23 options and inspect the probe arguments using the new $_probe_arg family
24 of convenience variables. You can obtain more information about SystemTap
25 in <http://sourceware.org/systemtap/>.
27 * GDB now supports reversible debugging on ARM, it allows you to
28 debug basic ARM and THUMB instructions, and provides
29 record/replay support.
31 * The option "symbol-reloading" has been deleted as it is no longer used.
35 ** GDB commands implemented in Python can now be put in command class
38 ** The "maint set python print-stack on|off" is now deleted.
40 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
41 apply "flag enum"-style pretty-printing to any enum.
43 ** gdb.lookup_symbol can now work when there is no current frame.
45 ** gdb.Symbol now has a 'line' attribute, holding the line number in
46 the source at which the symbol was defined.
48 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
49 method 'value'. The former indicates whether the symbol needs a
50 frame in order to compute its value, and the latter computes the
53 ** A new method 'referenced_value' on gdb.Value objects which can
54 dereference pointer as well as C++ reference values.
56 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
57 which return the global and static blocks (as gdb.Block objects),
58 of the underlying symbol table, respectively.
60 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
61 object associated with a PC value.
63 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
64 of the address range occupied by code for the current source line.
66 * Go language support.
67 GDB now supports debugging programs written in the Go programming
70 * GDBserver now supports stdio connections.
71 E.g. (gdb) target remote | ssh myhost gdbserver - hello
73 * The binary "gdbtui" can no longer be built or installed.
74 Use "gdb -tui" instead.
76 * GDB will now print "flag" enums specially. A flag enum is one where
77 all the enumerator values have no bits in common when pairwise
78 "and"ed. When printing a value whose type is a flag enum, GDB will
79 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
80 (gdb) print (enum E) 3
83 * The filename part of a linespec will now match trailing components
84 of a source file name. For example, "break gcc/expr.c:1000" will
85 now set a breakpoint in build/gcc/expr.c, but not
88 * The "info proc" and "generate-core-file" commands will now also
89 work on remote targets connected to GDBserver on Linux.
91 * The command "info catch" has been removed. It has been disabled
94 * The "catch exception" and "catch assert" commands now accept
95 a condition at the end of the command, much like the "break"
96 command does. For instance:
98 (gdb) catch exception Constraint_Error if Barrier = True
100 Previously, it was possible to add a condition to such catchpoints,
101 but it had to be done as a second step, after the catchpoint had been
102 created, using the "condition" command.
104 * The "info static-tracepoint-marker" command will now also work on
105 native Linux targets with in-process agent.
107 * GDB can now set breakpoints on inlined functions.
109 * The .gdb_index section has been updated to include symbols for
110 inlined functions. GDB will ignore older .gdb_index sections by
111 default, which could cause symbol files to be loaded more slowly
112 until their .gdb_index sections can be recreated. The new option
113 --use-deprecated-index-sections will cause GDB to use any older
114 .gdb_index sections it finds. This will restore performance, but
115 the ability to set breakpoints on inlined functions will be lost
116 in symbol files with older .gdb_index sections.
118 The .gdb_index section has also been updated to record more information
119 about each symbol. This speeds up the "info variables", "info functions"
120 and "info types" commands when used with programs having the .gdb_index
121 section, as well as speeding up debugging with shared libraries using
122 the .gdb_index section.
124 * Ada support for GDB/MI Variable Objects has been added.
126 * GDB can now support 'breakpoint always-inserted mode' in 'record'
131 ** New command -info-os is the MI equivalent of "info os".
133 ** Output logs ("set logging" and related) now include MI output.
137 ** "catch load" and "catch unload" can be used to stop when a shared
138 library is loaded or unloaded, respectively.
140 ** "enable count" can be used to auto-disable a breakpoint after
143 ** "info vtbl" can be used to show the virtual method tables for
144 C++ and Java objects.
146 ** "explore" and its sub commands "explore value" and "explore type"
147 can be used to reccursively explore values and types of
148 expressions. These commands are available only if GDB is
149 configured with '--with-python'.
151 ** "info auto-load" shows status of all kinds of auto-loaded files,
152 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
153 sequences of commands files, "info auto-load python-scripts"
154 shows status of auto-loading Python script files,
155 "info auto-load local-gdbinit" shows status of loading init file
156 (.gdbinit) from current directory and "info auto-load libthread-db" shows
157 status of inferior specific thread debugging shared library loading.
159 ** "info auto-load-scripts", "set auto-load-scripts on|off"
160 and "show auto-load-scripts" commands have been deprecated, use their
161 "info auto-load python-scripts", "set auto-load python-scripts on|off"
162 and "show auto-load python-scripts" counterparts instead.
164 ** "dprintf location,format,args..." creates a dynamic printf, which
165 is basically a breakpoint that does a printf and immediately
166 resumes your program's execution, so it is like a printf that you
167 can insert dynamically at runtime instead of at compiletime.
169 ** "set print symbol"
171 Controls whether GDB attempts to display the symbol, if any,
172 corresponding to addresses it prints. This defaults to "on", but
173 you can set it to "off" to restore GDB's previous behavior.
175 * Deprecated commands
177 ** For the Renesas Super-H architecture, the "regs" command has been
178 deprecated, and "info all-registers" should be used instead.
182 Renesas RL78 rl78-*-elf
183 HP OpenVMS ia64 ia64-hp-openvms*
185 * GDBserver supports evaluation of breakpoint conditions. When
186 support is advertised by GDBserver, GDB may be told to send the
187 breakpoint conditions in bytecode form to GDBserver. GDBserver
188 will only report the breakpoint trigger to GDB when its condition
194 show mips compression
195 Select the compressed ISA encoding used in functions that have no symbol
196 information available. The encoding can be set to either of:
199 and is updated automatically from ELF file flags if available.
201 set breakpoint condition-evaluation
202 show breakpoint condition-evaluation
203 Control whether breakpoint conditions are evaluated by GDB ("host") or by
204 GDBserver ("target"). Default option "auto" chooses the most efficient
206 This option can improve debugger efficiency depending on the speed of the
210 Disable auto-loading globally.
213 Show auto-loading setting of all kinds of auto-loaded files.
215 set auto-load gdb-scripts on|off
216 show auto-load gdb-scripts
217 Control auto-loading of GDB canned sequences of commands files.
219 set auto-load python-scripts on|off
220 show auto-load python-scripts
221 Control auto-loading of Python script files.
223 set auto-load local-gdbinit on|off
224 show auto-load local-gdbinit
225 Control loading of init file (.gdbinit) from current directory.
227 set auto-load libthread-db on|off
228 show auto-load libthread-db
229 Control auto-loading of inferior specific thread debugging shared library.
231 set auto-load scripts-directory <dir1>[:<dir2>...]
232 show auto-load scripts-directory
233 Set a list of directories from which to load auto-loaded scripts.
234 Automatically loaded Python scripts and GDB scripts are located in one
235 of the directories listed by this option.
236 The delimiter (':' above) may differ according to the host platform.
238 set auto-load safe-path <dir1>[:<dir2>...]
239 show auto-load safe-path
240 Set a list of directories from which it is safe to auto-load files.
241 The delimiter (':' above) may differ according to the host platform.
243 set debug auto-load on|off
245 Control display of debugging info for auto-loading the files above.
247 set dprintf-style gdb|call|agent
249 Control the way in which a dynamic printf is performed; "gdb"
250 requests a GDB printf command, while "call" causes dprintf to call a
251 function in the inferior. "agent" requests that the target agent
252 (such as GDBserver) do the printing.
254 set dprintf-function <expr>
255 show dprintf-function
256 set dprintf-channel <expr>
258 Set the function and optional first argument to the call when using
259 the "call" style of dynamic printf.
261 set disconnected-dprintf on|off
262 show disconnected-dprintf
263 Control whether agent-style dynamic printfs continue to be in effect
264 after GDB disconnects.
266 * New configure options
269 Configure default value for the 'set auto-load scripts-directory'
270 setting above. It defaults to '$debugdir:$datadir/auto-load',
271 $debugdir representing global debugging info directories (available
272 via 'show debug-file-directory') and $datadir representing GDB's data
273 directory (available via 'show data-directory').
275 --with-auto-load-safe-path
276 Configure default value for the 'set auto-load safe-path' setting
277 above. It defaults to the --with-auto-load-dir setting.
279 --without-auto-load-safe-path
280 Set 'set auto-load safe-path' to '/', effectively disabling this
285 z0/z1 conditional breakpoints extension
287 The z0/z1 breakpoint insertion packets have been extended to carry
288 a list of conditional expressions over to the remote stub depending on the
289 condition evaluation mode. The use of this extension can be controlled
290 via the "set remote conditional-breakpoints-packet" command.
294 Specify the signals which the remote stub may pass to the debugged
295 program without GDB involvement.
297 * New command line options
299 --init-command=FILE, -ix Like --command, -x but execute it
300 before loading inferior.
301 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
302 execute it before loading inferior.
304 *** Changes in GDB 7.4
306 * GDB now handles ambiguous linespecs more consistently; the existing
307 FILE:LINE support has been expanded to other types of linespecs. A
308 breakpoint will now be set on all matching locations in all
309 inferiors, and locations will be added or removed according to
312 * GDB now allows you to skip uninteresting functions and files when
313 stepping with the "skip function" and "skip file" commands.
315 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
316 and "show remote hardware-watchpoint-length-limit". These allows to
317 set or show the maximum length limit (in bytes) of a remote
318 target hardware watchpoint.
320 This allows e.g. to use "unlimited" hardware watchpoints with the
321 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
322 watchpoints are slower than real hardware watchpoints but are
323 significantly faster than gdb software watchpoints.
327 ** The register_pretty_printer function in module gdb.printing now takes
328 an optional `replace' argument. If True, the new printer replaces any
331 ** The "maint set python print-stack on|off" command has been
332 deprecated and will be deleted in GDB 7.5.
333 A new command: "set python print-stack none|full|message" has
334 replaced it. Additionally, the default for "print-stack" is
335 now "message", which just prints the error message without
338 ** A prompt substitution hook (prompt_hook) is now available to the
341 ** A new Python module, gdb.prompt has been added to the GDB Python
342 modules library. This module provides functionality for
343 escape sequences in prompts (used by set/show
344 extended-prompt). These escape sequences are replaced by their
347 ** Python commands and convenience-functions located in
348 'data-directory'/python/gdb/command and
349 'data-directory'/python/gdb/function are now automatically loaded
352 ** Blocks now provide four new attributes. global_block and
353 static_block will return the global and static blocks
354 respectively. is_static and is_global are boolean attributes
355 that indicate if the block is one of those two types.
357 ** Symbols now provide the "type" attribute, the type of the symbol.
359 ** The "gdb.breakpoint" function has been deprecated in favor of
362 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
363 of a function. This class is based on the "finish" command
364 available in the CLI.
366 ** Type objects for struct and union types now allow access to
367 the fields using standard Python dictionary (mapping) methods.
368 For example, "some_type['myfield']" now works, as does
371 ** A new event "gdb.new_objfile" has been added, triggered by loading a
374 ** A new function, "deep_items" has been added to the gdb.types
375 module in the GDB Python modules library. This function returns
376 an iterator over the fields of a struct or union type. Unlike
377 the standard Python "iteritems" method, it will recursively traverse
378 any anonymous fields.
382 ** "*stopped" events can report several new "reason"s, such as
385 ** Breakpoint changes are now notified using new async records, like
386 "=breakpoint-modified".
388 ** New command -ada-task-info.
390 * libthread-db-search-path now supports two special values: $sdir and $pdir.
391 $sdir specifies the default system locations of shared libraries.
392 $pdir specifies the directory where the libpthread used by the application
395 GDB no longer looks in $sdir and $pdir after it has searched the directories
396 mentioned in libthread-db-search-path. If you want to search those
397 directories, they must be specified in libthread-db-search-path.
398 The default value of libthread-db-search-path on GNU/Linux and Solaris
399 systems is now "$sdir:$pdir".
401 $pdir is not supported by gdbserver, it is currently ignored.
402 $sdir is supported by gdbserver.
404 * New configure option --with-iconv-bin.
405 When using the internationalization support like the one in the GNU C
406 library, GDB will invoke the "iconv" program to get a list of supported
407 character sets. If this program lives in a non-standard location, one can
408 use this option to specify where to find it.
410 * When natively debugging programs on PowerPC BookE processors running
411 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
412 watchpoints, which specify a mask in addition to an address to watch.
413 The mask specifies that some bits of an address (the bits which are
414 reset in the mask) should be ignored when matching the address accessed
415 by the inferior against the watchpoint address. See the "PowerPC Embedded"
416 section in the user manual for more details.
418 * The new option --once causes GDBserver to stop listening for connections once
419 the first connection is made. The listening port used by GDBserver will
420 become available after that.
422 * New commands "info macros" and "alias" have been added.
424 * New function parameters suffix @entry specifies value of function parameter
425 at the time the function got called. Entry values are available only since
431 "!" is now an alias of the "shell" command.
432 Note that no space is needed between "!" and SHELL COMMAND.
436 watch EXPRESSION mask MASK_VALUE
437 The watch command now supports the mask argument which allows creation
438 of masked watchpoints, if the current architecture supports this feature.
440 info auto-load-scripts [REGEXP]
441 This command was formerly named "maintenance print section-scripts".
442 It is now generally useful and is no longer a maintenance-only command.
444 info macro [-all] [--] MACRO
445 The info macro command has new options `-all' and `--'. The first for
446 printing all definitions of a macro. The second for explicitly specifying
447 the end of arguments and the beginning of the macro name in case the macro
448 name starts with a hyphen.
450 collect[/s] EXPRESSIONS
451 The tracepoint collect command now takes an optional modifier "/s"
452 that directs it to dereference pointer-to-character types and
453 collect the bytes of memory up to a zero byte. The behavior is
454 similar to what you see when you use the regular print command on a
455 string. An optional integer following the "/s" sets a bound on the
456 number of bytes that will be collected.
459 The trace start command now interprets any supplied arguments as a
460 note to be recorded with the trace run, with an effect similar to
461 setting the variable trace-notes.
464 The trace stop command now interprets any arguments as a note to be
465 mentioned along with the tstatus report that the trace was stopped
466 with a command. The effect is similar to setting the variable
469 * Tracepoints can now be enabled and disabled at any time after a trace
470 experiment has been started using the standard "enable" and "disable"
471 commands. It is now possible to start a trace experiment with no enabled
472 tracepoints; GDB will display a warning, but will allow the experiment to
473 begin, assuming that tracepoints will be enabled as needed while the trace
476 * Fast tracepoints on 32-bit x86-architectures can now be placed at
477 locations with 4-byte instructions, when they were previously
478 limited to locations with instructions of 5 bytes or longer.
482 set debug dwarf2-read
483 show debug dwarf2-read
484 Turns on or off display of debugging messages related to reading
485 DWARF debug info. The default is off.
487 set debug symtab-create
488 show debug symtab-create
489 Turns on or off display of debugging messages related to symbol table
490 creation. The default is off.
494 Set the GDB prompt, and allow escape sequences to be inserted to
495 display miscellaneous information (see 'help set extended-prompt'
496 for the list of sequences). This prompt (and any information
497 accessed through the escape sequences) is updated every time the
500 set print entry-values (both|compact|default|if-needed|no|only|preferred)
501 show print entry-values
502 Set printing of frame argument values at function entry. In some cases
503 GDB can determine the value of function argument which was passed by the
504 function caller, even if the value was modified inside the called function.
506 set debug entry-values
507 show debug entry-values
508 Control display of debugging info for determining frame argument values at
509 function entry and virtual tail call frames.
511 set basenames-may-differ
512 show basenames-may-differ
513 Set whether a source file may have multiple base names.
514 (A "base name" is the name of a file with the directory part removed.
515 Example: The base name of "/home/user/hello.c" is "hello.c".)
516 If set, GDB will canonicalize file names (e.g., expand symlinks)
517 before comparing them. Canonicalization is an expensive operation,
518 but it allows the same file be known by more than one base name.
519 If not set (the default), all source files are assumed to have just
520 one base name, and gdb will do file name comparisons more efficiently.
526 Set a user name and notes for the current and any future trace runs.
527 This is useful for long-running and/or disconnected traces, to
528 inform others (or yourself) as to who is running the trace, supply
529 contact information, or otherwise explain what is going on.
532 show trace-stop-notes
533 Set a note attached to the trace run, that is displayed when the
534 trace has been stopped by a tstop command. This is useful for
535 instance as an explanation, if you are stopping a trace run that was
536 started by someone else.
542 Dynamically enable a tracepoint in a started trace experiment.
546 Dynamically disable a tracepoint in a started trace experiment.
550 Set the user and notes of the trace run.
554 Query the current status of a tracepoint.
558 Query the minimum length of instruction at which a fast tracepoint may
561 * Dcache size (number of lines) and line-size are now runtime-configurable
562 via "set dcache line" and "set dcache line-size" commands.
566 Texas Instruments TMS320C6x tic6x-*-*
570 Renesas RL78 rl78-*-elf
572 *** Changes in GDB 7.3.1
574 * The build failure for NetBSD and OpenBSD targets have now been fixed.
576 *** Changes in GDB 7.3
578 * GDB has a new command: "thread find [REGEXP]".
579 It finds the thread id whose name, target id, or thread extra info
580 matches the given regular expression.
582 * The "catch syscall" command now works on mips*-linux* targets.
584 * The -data-disassemble MI command now supports modes 2 and 3 for
585 dumping the instruction opcodes.
587 * New command line options
589 -data-directory DIR Specify DIR as the "data-directory".
590 This is mostly for testing purposes.
592 * The "maint set python auto-load on|off" command has been renamed to
593 "set auto-load-scripts on|off".
595 * GDB has a new command: "set directories".
596 It is like the "dir" command except that it replaces the
597 source path list instead of augmenting it.
599 * GDB now understands thread names.
601 On GNU/Linux, "info threads" will display the thread name as set by
602 prctl or pthread_setname_np.
604 There is also a new command, "thread name", which can be used to
605 assign a name internally for GDB to display.
608 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
609 has been integrated into GDB.
613 ** The function gdb.Write now accepts an optional keyword 'stream'.
614 This keyword, when provided, will direct the output to either
615 stdout, stderr, or GDB's logging output.
617 ** Parameters can now be be sub-classed in Python, and in particular
618 you may implement the get_set_doc and get_show_doc functions.
619 This improves how Parameter set/show documentation is processed
620 and allows for more dynamic content.
622 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
623 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
624 have an is_valid method.
626 ** Breakpoints can now be sub-classed in Python, and in particular
627 you may implement a 'stop' function that is executed each time
628 the inferior reaches that breakpoint.
630 ** New function gdb.lookup_global_symbol looks up a global symbol.
632 ** GDB values in Python are now callable if the value represents a
633 function. For example, if 'some_value' represents a function that
634 takes two integer parameters and returns a value, you can call
635 that function like so:
637 result = some_value (10,20)
639 ** Module gdb.types has been added.
640 It contains a collection of utilities for working with gdb.Types objects:
641 get_basic_type, has_field, make_enum_dict.
643 ** Module gdb.printing has been added.
644 It contains utilities for writing and registering pretty-printers.
645 New classes: PrettyPrinter, SubPrettyPrinter,
646 RegexpCollectionPrettyPrinter.
647 New function: register_pretty_printer.
649 ** New commands "info pretty-printers", "enable pretty-printer" and
650 "disable pretty-printer" have been added.
652 ** gdb.parameter("directories") is now available.
654 ** New function gdb.newest_frame returns the newest frame in the
657 ** The gdb.InferiorThread class has a new "name" attribute. This
658 holds the thread's name.
660 ** Python Support for Inferior events.
661 Python scripts can add observers to be notified of events
662 occurring in the process being debugged.
663 The following events are currently supported:
664 - gdb.events.cont Continue event.
665 - gdb.events.exited Inferior exited event.
666 - gdb.events.stop Signal received, and Breakpoint hit events.
670 ** GDB now puts template parameters in scope when debugging in an
671 instantiation. For example, if you have:
673 template<int X> int func (void) { return X; }
675 then if you step into func<5>, "print X" will show "5". This
676 feature requires proper debuginfo support from the compiler; it
677 was added to GCC 4.5.
679 ** The motion commands "next", "finish", "until", and "advance" now
680 work better when exceptions are thrown. In particular, GDB will
681 no longer lose control of the inferior; instead, the GDB will
682 stop the inferior at the point at which the exception is caught.
683 This functionality requires a change in the exception handling
684 code that was introduced in GCC 4.5.
686 * GDB now follows GCC's rules on accessing volatile objects when
687 reading or writing target state during expression evaluation.
688 One notable difference to prior behavior is that "print x = 0"
689 no longer generates a read of x; the value of the assignment is
690 now always taken directly from the value being assigned.
692 * GDB now has some support for using labels in the program's source in
693 linespecs. For instance, you can use "advance label" to continue
694 execution to a label.
696 * GDB now has support for reading and writing a new .gdb_index
697 section. This section holds a fast index of DWARF debugging
698 information and can be used to greatly speed up GDB startup and
699 operation. See the documentation for `save gdb-index' for details.
701 * The "watch" command now accepts an optional "-location" argument.
702 When used, this causes GDB to watch the memory referred to by the
703 expression. Such a watchpoint is never deleted due to it going out
706 * GDB now supports thread debugging of core dumps on GNU/Linux.
708 GDB now activates thread debugging using the libthread_db library
709 when debugging GNU/Linux core dumps, similarly to when debugging
710 live processes. As a result, when debugging a core dump file, GDB
711 is now able to display pthread_t ids of threads. For example, "info
712 threads" shows the same output as when debugging the process when it
713 was live. In earlier releases, you'd see something like this:
716 * 1 LWP 6780 main () at main.c:10
718 While now you see this:
721 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
723 It is also now possible to inspect TLS variables when debugging core
726 When debugging a core dump generated on a machine other than the one
727 used to run GDB, you may need to point GDB at the correct
728 libthread_db library with the "set libthread-db-search-path"
729 command. See the user manual for more details on this command.
731 * When natively debugging programs on PowerPC BookE processors running
732 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
733 which stop execution of the inferior whenever it executes an instruction
734 at any address within the specified range. See the "PowerPC Embedded"
735 section in the user manual for more details.
737 * New features in the GDB remote stub, GDBserver
739 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
740 and i686 LynxOS (version 5.x).
742 ** GDBserver is now supported on Blackfin Linux.
744 * New native configurations
746 ia64 HP-UX ia64-*-hpux*
750 Analog Devices, Inc. Blackfin Processor bfin-*
752 * Ada task switching is now supported on sparc-elf targets when
753 debugging a program using the Ravenscar Profile. For more information,
754 see the "Tasking Support when using the Ravenscar Profile" section
755 in the GDB user manual.
757 * Guile support was removed.
759 * New features in the GNU simulator
761 ** The --map-info flag lists all known core mappings.
763 ** CFI flashes may be simulated via the "cfi" device.
765 *** Changes in GDB 7.2
767 * Shared library support for remote targets by default
769 When GDB is configured for a generic, non-OS specific target, like
770 for example, --target=arm-eabi or one of the many *-*-elf targets,
771 GDB now queries remote stubs for loaded shared libraries using the
772 `qXfer:libraries:read' packet. Previously, shared library support
773 was always disabled for such configurations.
777 ** Argument Dependent Lookup (ADL)
779 In C++ ADL lookup directs function search to the namespaces of its
780 arguments even if the namespace has not been imported.
790 Here the compiler will search for `foo' in the namespace of 'b'
791 and find A::foo. GDB now supports this. This construct is commonly
792 used in the Standard Template Library for operators.
794 ** Improved User Defined Operator Support
796 In addition to member operators, GDB now supports lookup of operators
797 defined in a namespace and imported with a `using' directive, operators
798 defined in the global scope, operators imported implicitly from an
799 anonymous namespace, and the ADL operators mentioned in the previous
801 GDB now also supports proper overload resolution for all the previously
802 mentioned flavors of operators.
804 ** static const class members
806 Printing of static const class members that are initialized in the
807 class definition has been fixed.
809 * Windows Thread Information Block access.
811 On Windows targets, GDB now supports displaying the Windows Thread
812 Information Block (TIB) structure. This structure is visible either
813 by using the new command `info w32 thread-information-block' or, by
814 dereferencing the new convenience variable named `$_tlb', a
815 thread-specific pointer to the TIB. This feature is also supported
816 when remote debugging using GDBserver.
820 Static tracepoints are calls in the user program into a tracing
821 library. One such library is a port of the LTTng kernel tracer to
822 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
823 When debugging with GDBserver, GDB now supports combining the GDB
824 tracepoint machinery with such libraries. For example: the user can
825 use GDB to probe a static tracepoint marker (a call from the user
826 program into the tracing library) with the new "strace" command (see
827 "New commands" below). This creates a "static tracepoint" in the
828 breakpoint list, that can be manipulated with the same feature set
829 as fast and regular tracepoints. E.g., collect registers, local and
830 global variables, collect trace state variables, and define
831 tracepoint conditions. In addition, the user can collect extra
832 static tracepoint marker specific data, by collecting the new
833 $_sdata internal variable. When analyzing the trace buffer, you can
834 inspect $_sdata like any other variable available to GDB. For more
835 information, see the "Tracepoints" chapter in GDB user manual. New
836 remote packets have been defined to support static tracepoints, see
837 the "New remote packets" section below.
839 * Better reconstruction of tracepoints after disconnected tracing
841 GDB will attempt to download the original source form of tracepoint
842 definitions when starting a trace run, and then will upload these
843 upon reconnection to the target, resulting in a more accurate
844 reconstruction of the tracepoints that are in use on the target.
848 You can now exercise direct control over the ways that GDB can
849 affect your program. For instance, you can disallow the setting of
850 breakpoints, so that the program can run continuously (assuming
851 non-stop mode). In addition, the "observer" variable is available
852 to switch all of the different controls; in observer mode, GDB
853 cannot affect the target's behavior at all, which is useful for
854 tasks like diagnosing live systems in the field.
856 * The new convenience variable $_thread holds the number of the
863 Return the address of the Windows Thread Information Block of a given thread.
867 In response to several of the tracepoint packets, the target may now
868 also respond with a number of intermediate `qRelocInsn' request
869 packets before the final result packet, to have GDB handle
870 relocating an instruction to execute at a different address. This
871 is particularly useful for stubs that support fast tracepoints. GDB
872 reports support for this feature in the qSupported packet.
876 List static tracepoint markers in the target program.
880 List static tracepoint markers at a given address in the target
883 qXfer:statictrace:read
885 Read the static trace data collected (by a `collect $_sdata'
886 tracepoint action). The remote stub reports support for this packet
887 to gdb's qSupported query.
891 Send the current settings of GDB's permission flags.
895 Send part of the source (textual) form of a tracepoint definition,
896 which includes location, conditional, and action list.
898 * The source command now accepts a -s option to force searching for the
899 script in the source search path even if the script name specifies
902 * New features in the GDB remote stub, GDBserver
904 - GDBserver now support tracepoints (including fast tracepoints, and
905 static tracepoints). The feature is currently supported by the
906 i386-linux and amd64-linux builds. See the "Tracepoints support
907 in gdbserver" section in the manual for more information.
909 GDBserver JIT compiles the tracepoint's conditional agent
910 expression bytecode into native code whenever possible for low
911 overhead dynamic tracepoints conditionals. For such tracepoints,
912 an expression that examines program state is evaluated when the
913 tracepoint is reached, in order to determine whether to capture
914 trace data. If the condition is simple and false, processing the
915 tracepoint finishes very quickly and no data is gathered.
917 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
918 for static tracepoints support.
920 - GDBserver now supports x86_64 Windows 64-bit debugging.
922 * GDB now sends xmlRegisters= in qSupported packet to indicate that
923 it understands register description.
925 * The --batch flag now disables pagination and queries.
927 * X86 general purpose registers
929 GDB now supports reading/writing byte, word and double-word x86
930 general purpose registers directly. This means you can use, say,
931 $ah or $ax to refer, respectively, to the byte register AH and
932 16-bit word register AX that are actually portions of the 32-bit
933 register EAX or 64-bit register RAX.
935 * The `commands' command now accepts a range of breakpoints to modify.
936 A plain `commands' following a command that creates multiple
937 breakpoints affects all the breakpoints set by that command. This
938 applies to breakpoints set by `rbreak', and also applies when a
939 single `break' command creates multiple breakpoints (e.g.,
940 breakpoints on overloaded c++ functions).
942 * The `rbreak' command now accepts a filename specification as part of
943 its argument, limiting the functions selected by the regex to those
944 in the specified file.
946 * Support for remote debugging Windows and SymbianOS shared libraries
947 from Unix hosts has been improved. Non Windows GDB builds now can
948 understand target reported file names that follow MS-DOS based file
949 system semantics, such as file names that include drive letters and
950 use the backslash character as directory separator. This makes it
951 possible to transparently use the "set sysroot" and "set
952 solib-search-path" on Unix hosts to point as host copies of the
953 target's shared libraries. See the new command "set
954 target-file-system-kind" described below, and the "Commands to
955 specify files" section in the user manual for more information.
959 eval template, expressions...
960 Convert the values of one or more expressions under the control
961 of the string template to a command line, and call it.
963 set target-file-system-kind unix|dos-based|auto
964 show target-file-system-kind
965 Set or show the assumed file system kind for target reported file
968 save breakpoints <filename>
969 Save all current breakpoint definitions to a file suitable for use
970 in a later debugging session. To read the saved breakpoint
971 definitions, use the `source' command.
973 `save tracepoints' is a new alias for `save-tracepoints'. The latter
976 info static-tracepoint-markers
977 Display information about static tracepoint markers in the target.
979 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
980 Define a static tracepoint by probing a marker at the given
981 function, line, address, or marker ID.
985 Enable and disable observer mode.
987 set may-write-registers on|off
988 set may-write-memory on|off
989 set may-insert-breakpoints on|off
990 set may-insert-tracepoints on|off
991 set may-insert-fast-tracepoints on|off
992 set may-interrupt on|off
993 Set individual permissions for GDB effects on the target. Note that
994 some of these settings can have undesirable or surprising
995 consequences, particularly when changed in the middle of a session.
996 For instance, disabling the writing of memory can prevent
997 breakpoints from being inserted, cause single-stepping to fail, or
998 even crash your program, if you disable after breakpoints have been
999 inserted. However, GDB should not crash.
1001 set record memory-query on|off
1002 show record memory-query
1003 Control whether to stop the inferior if memory changes caused
1004 by an instruction cannot be recorded.
1009 The disassemble command now supports "start,+length" form of two arguments.
1013 ** GDB now provides a new directory location, called the python directory,
1014 where Python scripts written for GDB can be installed. The location
1015 of that directory is <data-directory>/python, where <data-directory>
1016 is the GDB data directory. For more details, see section `Scripting
1017 GDB using Python' in the manual.
1019 ** The GDB Python API now has access to breakpoints, symbols, symbol
1020 tables, program spaces, inferiors, threads and frame's code blocks.
1021 Additionally, GDB Parameters can now be created from the API, and
1022 manipulated via set/show in the CLI.
1024 ** New functions gdb.target_charset, gdb.target_wide_charset,
1025 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1027 ** New exception gdb.GdbError.
1029 ** Pretty-printers are now also looked up in the current program space.
1031 ** Pretty-printers can now be individually enabled and disabled.
1033 ** GDB now looks for names of Python scripts to auto-load in a
1034 special section named `.debug_gdb_scripts', in addition to looking
1035 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1037 * Tracepoint actions were unified with breakpoint commands. In particular,
1038 there are no longer differences in "info break" output for breakpoints and
1039 tracepoints and the "commands" command can be used for both tracepoints and
1040 regular breakpoints.
1044 ARM Symbian arm*-*-symbianelf*
1046 * D language support.
1047 GDB now supports debugging programs written in the D programming
1050 * GDB now supports the extended ptrace interface for PowerPC which is
1051 available since Linux kernel version 2.6.34. This automatically enables
1052 any hardware breakpoints and additional hardware watchpoints available in
1053 the processor. The old ptrace interface exposes just one hardware
1054 watchpoint and no hardware breakpoints.
1056 * GDB is now able to use the Data Value Compare (DVC) register available on
1057 embedded PowerPC processors to implement in hardware simple watchpoint
1058 conditions of the form:
1060 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1062 This works in native GDB running on Linux kernels with the extended ptrace
1063 interface mentioned above.
1065 *** Changes in GDB 7.1
1069 ** Namespace Support
1071 GDB now supports importing of namespaces in C++. This enables the
1072 user to inspect variables from imported namespaces. Support for
1073 namepace aliasing has also been added. So, if a namespace is
1074 aliased in the current scope (e.g. namepace C=A; ) the user can
1075 print variables using the alias (e.g. (gdb) print C::x).
1079 All known bugs relating to the printing of virtual base class were
1080 fixed. It is now possible to call overloaded static methods using a
1085 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1086 and reinterpret_cast<> are now handled by the C++ expression parser.
1090 Xilinx MicroBlaze microblaze-*-*
1095 Xilinx MicroBlaze microblaze
1098 * Multi-program debugging.
1100 GDB now has support for multi-program (a.k.a. multi-executable or
1101 multi-exec) debugging. This allows for debugging multiple inferiors
1102 simultaneously each running a different program under the same GDB
1103 session. See "Debugging Multiple Inferiors and Programs" in the
1104 manual for more information. This implied some user visible changes
1105 in the multi-inferior support. For example, "info inferiors" now
1106 lists inferiors that are not running yet or that have exited
1107 already. See also "New commands" and "New options" below.
1109 * New tracing features
1111 GDB's tracepoint facility now includes several new features:
1113 ** Trace state variables
1115 GDB tracepoints now include support for trace state variables, which
1116 are variables managed by the target agent during a tracing
1117 experiment. They are useful for tracepoints that trigger each
1118 other, so for instance one tracepoint can count hits in a variable,
1119 and then a second tracepoint has a condition that is true when the
1120 count reaches a particular value. Trace state variables share the
1121 $-syntax of GDB convenience variables, and can appear in both
1122 tracepoint actions and condition expressions. Use the "tvariable"
1123 command to create, and "info tvariables" to view; see "Trace State
1124 Variables" in the manual for more detail.
1128 GDB now includes an option for defining fast tracepoints, which
1129 targets may implement more efficiently, such as by installing a jump
1130 into the target agent rather than a trap instruction. The resulting
1131 speedup can be by two orders of magnitude or more, although the
1132 tradeoff is that some program locations on some target architectures
1133 might not allow fast tracepoint installation, for instance if the
1134 instruction to be replaced is shorter than the jump. To request a
1135 fast tracepoint, use the "ftrace" command, with syntax identical to
1136 the regular trace command.
1138 ** Disconnected tracing
1140 It is now possible to detach GDB from the target while it is running
1141 a trace experiment, then reconnect later to see how the experiment
1142 is going. In addition, a new variable disconnected-tracing lets you
1143 tell the target agent whether to continue running a trace if the
1144 connection is lost unexpectedly.
1148 GDB now has the ability to save the trace buffer into a file, and
1149 then use that file as a target, similarly to you can do with
1150 corefiles. You can select trace frames, print data that was
1151 collected in them, and use tstatus to display the state of the
1152 tracing run at the moment that it was saved. To create a trace
1153 file, use "tsave <filename>", and to use it, do "target tfile
1156 ** Circular trace buffer
1158 You can ask the target agent to handle the trace buffer as a
1159 circular buffer, discarding the oldest trace frames to make room for
1160 newer ones, by setting circular-trace-buffer to on. This feature may
1161 not be available for all target agents.
1166 The disassemble command, when invoked with two arguments, now requires
1167 the arguments to be comma-separated.
1170 The info variables command now displays variable definitions. Files
1171 which only declare a variable are not shown.
1174 The source command is now capable of sourcing Python scripts.
1175 This feature is dependent on the debugger being build with Python
1178 Related to this enhancement is also the introduction of a new command
1179 "set script-extension" (see below).
1181 * New commands (for set/show, see "New options" below)
1183 record save [<FILENAME>]
1184 Save a file (in core file format) containing the process record
1185 execution log for replay debugging at a later time.
1187 record restore <FILENAME>
1188 Restore the process record execution log that was saved at an
1189 earlier time, for replay debugging.
1191 add-inferior [-copies <N>] [-exec <FILENAME>]
1194 clone-inferior [-copies <N>] [ID]
1195 Make a new inferior ready to execute the same program another
1196 inferior has loaded.
1201 maint info program-spaces
1202 List the program spaces loaded into GDB.
1204 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1205 show remote interrupt-sequence
1206 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1207 as the sequence to the remote target in order to interrupt the execution.
1208 Ctrl-C is a default. Some system prefers BREAK which is high level of
1209 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1210 Magic SysRq g. It is BREAK signal and character 'g'.
1212 set remote interrupt-on-connect [on | off]
1213 show remote interrupt-on-connect
1214 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1215 remote target when gdb connects to it. This is needed when you debug
1218 set remotebreak [on | off]
1220 Deprecated. Use "set/show remote interrupt-sequence" instead.
1222 tvariable $NAME [ = EXP ]
1223 Create or modify a trace state variable.
1226 List trace state variables and their values.
1228 delete tvariable $NAME ...
1229 Delete one or more trace state variables.
1232 Evaluate the given expressions without collecting anything into the
1233 trace buffer. (Valid in tracepoint actions only.)
1235 ftrace FN / FILE:LINE / *ADDR
1236 Define a fast tracepoint at the given function, line, or address.
1238 * New expression syntax
1240 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1241 GDB now parses 0b101010 identically with 42.
1245 set follow-exec-mode new|same
1246 show follow-exec-mode
1247 Control whether GDB reuses the same inferior across an exec call or
1248 creates a new one. This is useful to be able to restart the old
1249 executable after the inferior having done an exec call.
1251 set default-collect EXPR, ...
1252 show default-collect
1253 Define a list of expressions to be collected at each tracepoint.
1254 This is a useful way to ensure essential items are not overlooked,
1255 such as registers or a critical global variable.
1257 set disconnected-tracing
1258 show disconnected-tracing
1259 If set to 1, the target is instructed to continue tracing if it
1260 loses its connection to GDB. If 0, the target is to stop tracing
1263 set circular-trace-buffer
1264 show circular-trace-buffer
1265 If set to on, the target is instructed to use a circular trace buffer
1266 and discard the oldest trace frames instead of stopping the trace due
1267 to a full trace buffer. If set to off, the trace stops when the buffer
1268 fills up. Some targets may not support this.
1270 set script-extension off|soft|strict
1271 show script-extension
1272 If set to "off", the debugger does not perform any script language
1273 recognition, and all sourced files are assumed to be GDB scripts.
1274 If set to "soft" (the default), files are sourced according to
1275 filename extension, falling back to GDB scripts if the first
1277 If set to "strict", files are sourced according to filename extension.
1279 set ada trust-PAD-over-XVS on|off
1280 show ada trust-PAD-over-XVS
1281 If off, activate a workaround against a bug in the debugging information
1282 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1283 the GCC sources for more information about the GNAT encoding and
1284 PAD types in particular). It is always safe to set this option to
1285 off, but this introduces a slight performance penalty. The default
1288 * Python API Improvements
1290 ** GDB provides the new class gdb.LazyString. This is useful in
1291 some pretty-printing cases. The new method gdb.Value.lazy_string
1292 provides a simple way to create objects of this type.
1294 ** The fields returned by gdb.Type.fields now have an
1295 `is_base_class' attribute.
1297 ** The new method gdb.Type.range returns the range of an array type.
1299 ** The new method gdb.parse_and_eval can be used to parse and
1300 evaluate an expression.
1302 * New remote packets
1305 Define a trace state variable.
1308 Get the current value of a trace state variable.
1311 Set desired tracing behavior upon disconnection.
1314 Set the trace buffer to be linear or circular.
1317 Get data about the tracepoints currently in use.
1321 Process record now works correctly with hardware watchpoints.
1323 Multiple bug fixes have been made to the mips-irix port, making it
1324 much more reliable. In particular:
1325 - Debugging threaded applications is now possible again. Previously,
1326 GDB would hang while starting the program, or while waiting for
1327 the program to stop at a breakpoint.
1328 - Attaching to a running process no longer hangs.
1329 - An error occurring while loading a core file has been fixed.
1330 - Changing the value of the PC register now works again. This fixes
1331 problems observed when using the "jump" command, or when calling
1332 a function from GDB, or even when assigning a new value to $pc.
1333 - With the "finish" and "return" commands, the return value for functions
1334 returning a small array is now correctly printed.
1335 - It is now possible to break on shared library code which gets executed
1336 during a shared library init phase (code executed while executing
1337 their .init section). Previously, the breakpoint would have no effect.
1338 - GDB is now able to backtrace through the signal handler for
1339 non-threaded programs.
1341 PIE (Position Independent Executable) programs debugging is now supported.
1342 This includes debugging execution of PIC (Position Independent Code) shared
1343 libraries although for that, it should be possible to run such libraries as an
1346 *** Changes in GDB 7.0
1348 * GDB now has an interface for JIT compilation. Applications that
1349 dynamically generate code can create symbol files in memory and register
1350 them with GDB. For users, the feature should work transparently, and
1351 for JIT developers, the interface is documented in the GDB manual in the
1352 "JIT Compilation Interface" chapter.
1354 * Tracepoints may now be conditional. The syntax is as for
1355 breakpoints; either an "if" clause appended to the "trace" command,
1356 or the "condition" command is available. GDB sends the condition to
1357 the target for evaluation using the same bytecode format as is used
1358 for tracepoint actions.
1360 * The disassemble command now supports: an optional /r modifier, print the
1361 raw instructions in hex as well as in symbolic form, and an optional /m
1362 modifier to print mixed source+assembly.
1364 * Process record and replay
1366 In a architecture environment that supports ``process record and
1367 replay'', ``process record and replay'' target can record a log of
1368 the process execution, and replay it with both forward and reverse
1371 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1372 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1373 set execution-direction {forward|reverse}, for targets that support
1376 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1377 feature is available with a native GDB running on kernel version
1380 * GDB now has support for multi-byte and wide character sets on the
1381 target. Strings whose character type is wchar_t, char16_t, or
1382 char32_t are now correctly printed. GDB supports wide- and unicode-
1383 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1384 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1385 `printf'. This feature requires iconv to work properly; if your
1386 system does not have a working iconv, GDB can use GNU libiconv. See
1387 the installation instructions for more information.
1389 * GDB now supports automatic retrieval of shared library files from
1390 remote targets. To use this feature, specify a system root that begins
1391 with the `remote:' prefix, either via the `set sysroot' command or via
1392 the `--with-sysroot' configure-time option.
1394 * "info sharedlibrary" now takes an optional regex of libraries to show,
1395 and it now reports if a shared library has no debugging information.
1397 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1398 now complete on file names.
1400 * When completing in expressions, gdb will attempt to limit
1401 completions to allowable structure or union fields, where appropriate.
1402 For instance, consider:
1404 # struct example { int f1; double f2; };
1405 # struct example variable;
1408 If the user types TAB at the end of this command line, the available
1409 completions will be "f1" and "f2".
1411 * Inlined functions are now supported. They show up in backtraces, and
1412 the "step", "next", and "finish" commands handle them automatically.
1414 * GDB now supports the token-splicing (##) and stringification (#)
1415 operators when expanding macros. It also supports variable-arity
1418 * GDB now supports inspecting extra signal information, exported by
1419 the new $_siginfo convenience variable. The feature is currently
1420 implemented on linux ARM, i386 and amd64.
1422 * GDB can now display the VFP floating point registers and NEON vector
1423 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1424 can provide these registers (requires Linux 2.6.30 or later). Remote
1425 and simulator targets may also provide them.
1427 * New remote packets
1430 Search memory for a sequence of bytes.
1433 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1434 operation over reliable transport links. Use of this packet is
1435 controlled by the `set remote noack-packet' command.
1438 Kill the process with the specified process ID. Use this in preference
1439 to `k' when multiprocess protocol extensions are supported.
1442 Obtains additional operating system information
1446 Read or write additional signal information.
1448 * Removed remote protocol undocumented extension
1450 An undocumented extension to the remote protocol's `S' stop reply
1451 packet that permited the stub to pass a process id was removed.
1452 Remote servers should use the `T' stop reply packet instead.
1454 * GDB now supports multiple function calling conventions according to the
1455 DWARF-2 DW_AT_calling_convention function attribute.
1457 * The SH target utilizes the aforementioned change to distinguish between gcc
1458 and Renesas calling convention. It also adds the new CLI commands
1459 `set/show sh calling-convention'.
1461 * GDB can now read compressed debug sections, as produced by GNU gold
1462 with the --compress-debug-sections=zlib flag.
1464 * 64-bit core files are now supported on AIX.
1466 * Thread switching is now supported on Tru64.
1468 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1469 which will be allocated using malloc later in program execution.
1471 * The qXfer:libraries:read remote procotol packet now allows passing a
1472 list of section offsets.
1474 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1475 conditions handling signals delivered during attach or thread creation
1476 have also been fixed.
1478 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1479 From the user's standpoint, all unqualified instances of True and False
1480 are treated as the standard definitions, regardless of context.
1482 * GDB now parses C++ symbol and type names more flexibly. For
1485 template<typename T> class C { };
1488 GDB will now correctly handle all of:
1490 ptype C<char const *>
1491 ptype C<char const*>
1492 ptype C<const char *>
1493 ptype C<const char*>
1495 * New features in the GDB remote stub, gdbserver
1497 - The "--wrapper" command-line argument tells gdbserver to use a
1498 wrapper program to launch programs for debugging.
1500 - On PowerPC and S/390 targets, it is now possible to use a single
1501 gdbserver executable to debug both 32-bit and 64-bit programs.
1502 (This requires gdbserver itself to be built as a 64-bit executable.)
1504 - gdbserver uses the new noack protocol mode for TCP connections to
1505 reduce communications latency, if also supported and enabled in GDB.
1507 - Support for the sparc64-linux-gnu target is now included in
1510 - The amd64-linux build of gdbserver now supports debugging both
1511 32-bit and 64-bit programs.
1513 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1514 now support hardware watchpoints, and will use them automatically
1519 GDB now has support for scripting using Python. Whether this is
1520 available is determined at configure time.
1522 New GDB commands can now be written in Python.
1524 * Ada tasking support
1526 Ada tasks can now be inspected in GDB. The following commands have
1530 Print the list of Ada tasks.
1532 Print detailed information about task number N.
1534 Print the task number of the current task.
1536 Switch the context of debugging to task number N.
1538 * Support for user-defined prefixed commands. The "define" command can
1539 add new commands to existing prefixes, e.g. "target".
1541 * Multi-inferior, multi-process debugging.
1543 GDB now has generalized support for multi-inferior debugging. See
1544 "Debugging Multiple Inferiors" in the manual for more information.
1545 Although availability still depends on target support, the command
1546 set is more uniform now. The GNU/Linux specific multi-forks support
1547 has been migrated to this new framework. This implied some user
1548 visible changes; see "New commands" and also "Removed commands"
1551 * Target descriptions can now describe the target OS ABI. See the
1552 "Target Description Format" section in the user manual for more
1555 * Target descriptions can now describe "compatible" architectures
1556 to indicate that the target can execute applications for a different
1557 architecture in addition to those for the main target architecture.
1558 See the "Target Description Format" section in the user manual for
1561 * Multi-architecture debugging.
1563 GDB now includes general supports for debugging applications on
1564 hybrid systems that use more than one single processor architecture
1565 at the same time. Each such hybrid architecture still requires
1566 specific support to be added. The only hybrid architecture supported
1567 in this version of GDB is the Cell Broadband Engine.
1569 * GDB now supports integrated debugging of Cell/B.E. applications that
1570 use both the PPU and SPU architectures. To enable support for hybrid
1571 Cell/B.E. debugging, you need to configure GDB to support both the
1572 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1573 --enable-targets configure option.
1575 * Non-stop mode debugging.
1577 For some targets, GDB now supports an optional mode of operation in
1578 which you can examine stopped threads while other threads continue
1579 to execute freely. This is referred to as non-stop mode, with the
1580 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1581 section in the user manual for more information.
1583 To be able to support remote non-stop debugging, a remote stub needs
1584 to implement the non-stop mode remote protocol extensions, as
1585 described in the "Remote Non-Stop" section of the user manual. The
1586 GDB remote stub, gdbserver, has been adjusted to support these
1587 extensions on linux targets.
1589 * New commands (for set/show, see "New options" below)
1591 catch syscall [NAME(S) | NUMBER(S)]
1592 Catch system calls. Arguments, which should be names of system
1593 calls or their numbers, mean catch only those syscalls. Without
1594 arguments, every syscall will be caught. When the inferior issues
1595 any of the specified syscalls, GDB will stop and announce the system
1596 call, both when it is called and when its call returns. This
1597 feature is currently available with a native GDB running on the
1598 Linux Kernel, under the following architectures: x86, x86_64,
1599 PowerPC and PowerPC64.
1601 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1603 Search memory for a sequence of bytes.
1605 maint set python print-stack
1606 maint show python print-stack
1607 Show a stack trace when an error is encountered in a Python script.
1610 Invoke CODE by passing it to the Python interpreter.
1615 These allow macros to be defined, undefined, and listed
1619 Show operating system information about processes.
1622 List the inferiors currently under GDB's control.
1625 Switch focus to inferior number NUM.
1628 Detach from inferior number NUM.
1631 Kill inferior number NUM.
1635 set spu stop-on-load
1636 show spu stop-on-load
1637 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1639 set spu auto-flush-cache
1640 show spu auto-flush-cache
1641 Control whether to automatically flush the software-managed cache
1642 during Cell/B.E. debugging.
1644 set sh calling-convention
1645 show sh calling-convention
1646 Control the calling convention used when calling SH target functions.
1649 show debug timestamp
1650 Control display of timestamps with GDB debugging output.
1652 set disassemble-next-line
1653 show disassemble-next-line
1654 Control display of disassembled source lines or instructions when
1657 set remote noack-packet
1658 show remote noack-packet
1659 Set/show the use of remote protocol QStartNoAckMode packet. See above
1660 under "New remote packets."
1662 set remote query-attached-packet
1663 show remote query-attached-packet
1664 Control use of remote protocol `qAttached' (query-attached) packet.
1666 set remote read-siginfo-object
1667 show remote read-siginfo-object
1668 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1671 set remote write-siginfo-object
1672 show remote write-siginfo-object
1673 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1676 set remote reverse-continue
1677 show remote reverse-continue
1678 Control use of remote protocol 'bc' (reverse-continue) packet.
1680 set remote reverse-step
1681 show remote reverse-step
1682 Control use of remote protocol 'bs' (reverse-step) packet.
1684 set displaced-stepping
1685 show displaced-stepping
1686 Control displaced stepping mode. Displaced stepping is a way to
1687 single-step over breakpoints without removing them from the debuggee.
1688 Also known as "out-of-line single-stepping".
1691 show debug displaced
1692 Control display of debugging info for displaced stepping.
1694 maint set internal-error
1695 maint show internal-error
1696 Control what GDB does when an internal error is detected.
1698 maint set internal-warning
1699 maint show internal-warning
1700 Control what GDB does when an internal warning is detected.
1705 Use a wrapper program to launch programs for debugging.
1707 set multiple-symbols (all|ask|cancel)
1708 show multiple-symbols
1709 The value of this variable can be changed to adjust the debugger behavior
1710 when an expression or a breakpoint location contains an ambiguous symbol
1711 name (an overloaded function name, for instance).
1713 set breakpoint always-inserted
1714 show breakpoint always-inserted
1715 Keep breakpoints always inserted in the target, as opposed to inserting
1716 them when resuming the target, and removing them when the target stops.
1717 This option can improve debugger performance on slow remote targets.
1719 set arm fallback-mode (arm|thumb|auto)
1720 show arm fallback-mode
1721 set arm force-mode (arm|thumb|auto)
1723 These commands control how ARM GDB determines whether instructions
1724 are ARM or Thumb. The default for both settings is auto, which uses
1725 the current CPSR value for instructions without symbols; previous
1726 versions of GDB behaved as if "set arm fallback-mode arm".
1728 set disable-randomization
1729 show disable-randomization
1730 Standalone programs run with the virtual address space randomization enabled
1731 by default on some platforms. This option keeps the addresses stable across
1732 multiple debugging sessions.
1736 Control whether other threads are stopped or not when some thread hits
1741 Requests that asynchronous execution is enabled in the target, if available.
1742 In this case, it's possible to resume target in the background, and interact
1743 with GDB while the target is running. "show target-async" displays the
1744 current state of asynchronous execution of the target.
1746 set target-wide-charset
1747 show target-wide-charset
1748 The target-wide-charset is the name of the character set that GDB
1749 uses when printing characters whose type is wchar_t.
1751 set tcp auto-retry (on|off)
1753 set tcp connect-timeout
1754 show tcp connect-timeout
1755 These commands allow GDB to retry failed TCP connections to a remote stub
1756 with a specified timeout period; this is useful if the stub is launched
1757 in parallel with GDB but may not be ready to accept connections immediately.
1759 set libthread-db-search-path
1760 show libthread-db-search-path
1761 Control list of directories which GDB will search for appropriate
1764 set schedule-multiple (on|off)
1765 show schedule-multiple
1766 Allow GDB to resume all threads of all processes or only threads of
1767 the current process.
1771 Use more aggressive caching for accesses to the stack. This improves
1772 performance of remote debugging (particularly backtraces) without
1773 affecting correctness.
1775 set interactive-mode (on|off|auto)
1776 show interactive-mode
1777 Control whether GDB runs in interactive mode (on) or not (off).
1778 When in interactive mode, GDB waits for the user to answer all
1779 queries. Otherwise, GDB does not wait and assumes the default
1780 answer. When set to auto (the default), GDB determines which
1781 mode to use based on the stdin settings.
1786 For program forks, this is replaced by the new more generic `info
1787 inferiors' command. To list checkpoints, you can still use the
1788 `info checkpoints' command, which was an alias for the `info forks'
1792 Replaced by the new `inferior' command. To switch between
1793 checkpoints, you can still use the `restart' command, which was an
1794 alias for the `fork' command.
1797 This is removed, since some targets don't have a notion of
1798 processes. To switch between processes, you can still use the
1799 `inferior' command using GDB's own inferior number.
1802 For program forks, this is replaced by the new more generic `kill
1803 inferior' command. To delete a checkpoint, you can still use the
1804 `delete checkpoint' command, which was an alias for the `delete
1808 For program forks, this is replaced by the new more generic `detach
1809 inferior' command. To detach a checkpoint, you can still use the
1810 `detach checkpoint' command, which was an alias for the `detach
1813 * New native configurations
1815 x86/x86_64 Darwin i[34567]86-*-darwin*
1817 x86_64 MinGW x86_64-*-mingw*
1821 Lattice Mico32 lm32-*
1822 x86 DICOS i[34567]86-*-dicos*
1823 x86_64 DICOS x86_64-*-dicos*
1826 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1827 (mingw32ce) debugging.
1833 These commands were actually not implemented on any target.
1835 *** Changes in GDB 6.8
1837 * New native configurations
1839 NetBSD/hppa hppa*-*netbsd*
1840 Xtensa GNU/Linux xtensa*-*-linux*
1844 NetBSD/hppa hppa*-*-netbsd*
1845 Xtensa GNU/Lunux xtensa*-*-linux*
1847 * Change in command line behavior -- corefiles vs. process ids.
1849 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1850 attaching to process NUMBER fails, GDB no longer attempts to open a
1851 core file named NUMBER. Attaching to a program using the -c option
1852 is no longer supported. Instead, use the '-p' or '--pid' options.
1854 * GDB can now be built as a native debugger for debugging Windows x86
1855 (mingw32) Portable Executable (PE) programs.
1857 * Pending breakpoints no longer change their number when their address
1860 * GDB now supports breakpoints with multiple locations,
1861 including breakpoints on C++ constructors, inside C++ templates,
1862 and in inlined functions.
1864 * GDB's ability to debug optimized code has been improved. GDB more
1865 accurately identifies function bodies and lexical blocks that occupy
1866 more than one contiguous range of addresses.
1868 * Target descriptions can now describe registers for PowerPC.
1870 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1871 registers on PowerPC targets.
1873 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1874 targets even when the libthread_db library is not available.
1876 * The GDB remote stub, gdbserver, now supports the new file transfer
1877 commands (remote put, remote get, and remote delete).
1879 * The GDB remote stub, gdbserver, now supports run and attach in
1880 extended-remote mode.
1882 * hppa*64*-*-hpux11* target broken
1883 The debugger is unable to start a program and fails with the following
1884 error: "Error trying to get information about dynamic linker".
1885 The gdb-6.7 release is also affected.
1887 * GDB now supports the --enable-targets= configure option to allow
1888 building a single GDB executable that supports multiple remote
1889 target architectures.
1891 * GDB now supports debugging C and C++ programs which use the
1892 Decimal Floating Point extension. In addition, the PowerPC target
1893 now has a set of pseudo-registers to inspect decimal float values
1894 stored in two consecutive float registers.
1896 * The -break-insert MI command can optionally create pending
1899 * Improved support for debugging Ada
1900 Many improvements to the Ada language support have been made. These
1902 - Better support for Ada2005 interface types
1903 - Improved handling of arrays and slices in general
1904 - Better support for Taft-amendment types
1905 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1907 - Improved command completion in Ada
1910 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1915 set print frame-arguments (all|scalars|none)
1916 show print frame-arguments
1917 The value of this variable can be changed to control which argument
1918 values should be printed by the debugger when displaying a frame.
1923 Transfer files to and from a remote target, and delete remote files.
1930 Transfer files to and from a remote target, and delete remote files.
1932 * New remote packets
1939 Open, close, read, write, and delete files on the remote system.
1942 Attach to an existing process on the remote system, in extended-remote
1946 Run a new process on the remote system, in extended-remote mode.
1948 *** Changes in GDB 6.7
1950 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1951 bfd, libiberty and opcodes, as revealed by static analysis donated by
1952 Coverity, Inc. (http://scan.coverity.com).
1954 * When looking up multiply-defined global symbols, GDB will now prefer the
1955 symbol definition in the current shared library if it was built using the
1956 -Bsymbolic linker option.
1958 * When the Text User Interface (TUI) is not configured, GDB will now
1959 recognize the -tui command-line option and print a message that the TUI
1962 * The GDB remote stub, gdbserver, now has lower overhead for high
1963 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1965 * GDB for MIPS targets now autodetects whether a remote target provides
1966 32-bit or 64-bit register values.
1968 * Support for C++ member pointers has been improved.
1970 * GDB now understands XML target descriptions, which specify the
1971 target's overall architecture. GDB can read a description from
1972 a local file or over the remote serial protocol.
1974 * Vectors of single-byte data use a new integer type which is not
1975 automatically displayed as character or string data.
1977 * The /s format now works with the print command. It displays
1978 arrays of single-byte integers and pointers to single-byte integers
1981 * Target descriptions can now describe target-specific registers,
1982 for architectures which have implemented the support (currently
1983 only ARM, M68K, and MIPS).
1985 * GDB and the GDB remote stub, gdbserver, now support the XScale
1988 * The GDB remote stub, gdbserver, has been updated to support
1989 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1990 has been rewritten to use the standard GDB remote protocol.
1992 * GDB can now step into C++ functions which are called through thunks.
1994 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1996 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1997 layout. It also supports a TextSeg= and DataSeg= response when only
1998 segment base addresses (rather than offsets) are available.
2000 * The /i format now outputs any trailing branch delay slot instructions
2001 immediately following the last instruction within the count specified.
2003 * The GDB remote protocol "T" stop reply packet now supports a
2004 "library" response. Combined with the new "qXfer:libraries:read"
2005 packet, this response allows GDB to debug shared libraries on targets
2006 where the operating system manages the list of loaded libraries (e.g.
2007 Windows and SymbianOS).
2009 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2010 (DLLs) on Windows and Windows CE targets.
2012 * GDB now supports a faster verification that a .debug file matches its binary
2013 according to its build-id signature, if the signature is present.
2019 Enable or disable hardware flow control (RTS/CTS) on the serial port
2020 when debugging using remote targets.
2022 set mem inaccessible-by-default
2023 show mem inaccessible-by-default
2024 If the target supplies a memory map, for instance via the remote
2025 protocol's "qXfer:memory-map:read" packet, setting this variable
2026 prevents GDB from accessing memory outside the memory map. This
2027 is useful for targets with memory mapped registers or which react
2028 badly to accesses of unmapped address space.
2030 set breakpoint auto-hw
2031 show breakpoint auto-hw
2032 If the target supplies a memory map, for instance via the remote
2033 protocol's "qXfer:memory-map:read" packet, setting this variable
2034 lets GDB use hardware breakpoints automatically for memory regions
2035 where it can not use software breakpoints. This covers both the
2036 "break" command and internal breakpoints used for other commands
2037 including "next" and "finish".
2040 catch exception unhandled
2041 Stop the program execution when Ada exceptions are raised.
2044 Stop the program execution when an Ada assertion failed.
2048 Set an alternate system root for target files. This is a more
2049 general version of "set solib-absolute-prefix", which is now
2050 an alias to "set sysroot".
2053 Provide extended SPU facility status information. This set of
2054 commands is available only when debugging the Cell/B.E. SPU
2057 * New native configurations
2059 OpenBSD/sh sh*-*openbsd*
2062 unset tdesc filename
2064 Use the specified local file as an XML target description, and do
2065 not query the target for its built-in description.
2069 OpenBSD/sh sh*-*-openbsd*
2070 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2071 Toshiba Media Processor mep-elf
2073 * New remote packets
2076 Ignore the specified signals; pass them directly to the debugged program
2077 without stopping other threads or reporting them to GDB.
2079 qXfer:features:read:
2080 Read an XML target description from the target, which describes its
2085 Read or write contents of an spufs file on the target system. These
2086 packets are available only on the Cell/B.E. SPU architecture.
2088 qXfer:libraries:read:
2089 Report the loaded shared libraries. Combined with new "T" packet
2090 response, this packet allows GDB to debug shared libraries on
2091 targets where the operating system manages the list of loaded
2092 libraries (e.g. Windows and SymbianOS).
2096 Support for these obsolete configurations has been removed.
2104 i[34567]86-*-lynxos*
2105 i[34567]86-*-netware*
2106 i[34567]86-*-sco3.2v5*
2107 i[34567]86-*-sco3.2v4*
2109 i[34567]86-*-sysv4.2*
2112 i[34567]86-*-unixware2*
2113 i[34567]86-*-unixware*
2122 * Other removed features
2129 Various m68k-only ROM monitors.
2136 Various Renesas ROM monitors and debugging interfaces for SH and
2141 Support for a Macraigor serial interface to on-chip debugging.
2142 GDB does not directly support the newer parallel or USB
2147 A debug information format. The predecessor to DWARF 2 and
2148 DWARF 3, which are still supported.
2150 Support for the HP aCC compiler on HP-UX/PA-RISC
2152 SOM-encapsulated symbolic debugging information, automatic
2153 invocation of pxdb, and the aCC custom C++ ABI. This does not
2154 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2155 with aCC can still be debugged on an assembly level.
2157 MIPS ".pdr" sections
2159 A MIPS-specific format used to describe stack frame layout
2160 in debugging information.
2164 GDB could work with an older version of Guile to debug
2165 the interpreter and Scheme programs running in it.
2167 set mips stack-arg-size
2168 set mips saved-gpreg-size
2170 Use "set mips abi" to control parameter passing for MIPS.
2172 *** Changes in GDB 6.6
2177 Cell Broadband Engine SPU spu-elf
2179 * GDB can now be configured as a cross-debugger targeting native Windows
2180 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2181 running on a Windows system over TCP/IP to debug Windows programs.
2183 * The GDB remote stub, gdbserver, has been updated to support Windows and
2184 Cygwin debugging. Both single-threaded and multi-threaded programs are
2187 * The "set trust-readonly-sections" command works again. This command was
2188 broken in GDB 6.3, 6.4, and 6.5.
2190 * The "load" command now supports writing to flash memory, if the remote
2191 stub provides the required support.
2193 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2194 longer requires symbolic debug information (e.g. DWARF-2).
2199 unset substitute-path
2200 show substitute-path
2201 Manage a list of substitution rules that GDB uses to rewrite the name
2202 of the directories where the sources are located. This can be useful
2203 for instance when the sources were moved to a different location
2204 between compilation and debugging.
2208 Print each CLI command as it is executed. Each command is prefixed with
2209 a number of `+' symbols representing the nesting depth.
2210 The source command now has a `-v' option to enable the same feature.
2214 The ARM Demon monitor support (RDP protocol, "target rdp").
2216 Kernel Object Display, an embedded debugging feature which only worked with
2217 an obsolete version of Cisco IOS.
2219 The 'set download-write-size' and 'show download-write-size' commands.
2221 * New remote packets
2224 Tell a stub about GDB client features, and request remote target features.
2225 The first feature implemented is PacketSize, which allows the target to
2226 specify the size of packets it can handle - to minimize the number of
2227 packets required and improve performance when connected to a remote
2231 Fetch an OS auxilliary vector from the remote stub. This packet is a
2232 more efficient replacement for qPart:auxv:read.
2234 qXfer:memory-map:read:
2235 Fetch a memory map from the remote stub, including information about
2236 RAM, ROM, and flash memory devices.
2241 Erase and program a flash memory device.
2243 * Removed remote packets
2246 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2247 used it, and only gdbserver implemented it.
2249 *** Changes in GDB 6.5
2253 Renesas M32C/M16C m32c-elf
2255 Morpho Technologies ms1 ms1-elf
2259 init-if-undefined Initialize a convenience variable, but
2260 only if it doesn't already have a value.
2262 The following commands are presently only implemented for native GNU/Linux:
2264 checkpoint Save a snapshot of the program state.
2266 restart <n> Return the program state to a
2267 previously saved state.
2269 info checkpoints List currently saved checkpoints.
2271 delete-checkpoint <n> Delete a previously saved checkpoint.
2273 set|show detach-on-fork Tell gdb whether to detach from a newly
2274 forked process, or to keep debugging it.
2276 info forks List forks of the user program that
2277 are available to be debugged.
2279 fork <n> Switch to debugging one of several
2280 forks of the user program that are
2281 available to be debugged.
2283 delete-fork <n> Delete a fork from the list of forks
2284 that are available to be debugged (and
2285 kill the forked process).
2287 detach-fork <n> Delete a fork from the list of forks
2288 that are available to be debugged (and
2289 allow the process to continue).
2293 Morpho Technologies ms2 ms1-elf
2295 * Improved Windows host support
2297 GDB now builds as a cross debugger hosted on i686-mingw32, including
2298 native console support, and remote communications using either
2299 network sockets or serial ports.
2301 * Improved Modula-2 language support
2303 GDB can now print most types in the Modula-2 syntax. This includes:
2304 basic types, set types, record types, enumerated types, range types,
2305 pointer types and ARRAY types. Procedure var parameters are correctly
2306 printed and hexadecimal addresses and character constants are also
2307 written in the Modula-2 syntax. Best results can be obtained by using
2308 GNU Modula-2 together with the -gdwarf-2 command line option.
2312 The ARM rdi-share module.
2314 The Netware NLM debug server.
2316 *** Changes in GDB 6.4
2318 * New native configurations
2320 OpenBSD/arm arm*-*-openbsd*
2321 OpenBSD/mips64 mips64-*-openbsd*
2325 Morpho Technologies ms1 ms1-elf
2327 * New command line options
2329 --batch-silent As for --batch, but totally silent.
2330 --return-child-result The debugger will exist with the same value
2331 the child (debugged) program exited with.
2332 --eval-command COMMAND, -ex COMMAND
2333 Execute a single GDB CLI command. This may be
2334 specified multiple times and in conjunction
2335 with the --command (-x) option.
2337 * Deprecated commands removed
2339 The following commands, that were deprecated in 2000, have been
2343 set|show arm disassembly-flavor set|show arm disassembler
2344 othernames set arm disassembler
2345 set|show remotedebug set|show debug remote
2346 set|show archdebug set|show debug arch
2347 set|show eventdebug set|show debug event
2350 * New BSD user-level threads support
2352 It is now possible to debug programs using the user-level threads
2353 library on OpenBSD and FreeBSD. Currently supported (target)
2356 FreeBSD/amd64 x86_64-*-freebsd*
2357 FreeBSD/i386 i386-*-freebsd*
2358 OpenBSD/i386 i386-*-openbsd*
2360 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2361 are not yet supported.
2363 * New support for Matsushita MN10300 w/sim added
2364 (Work in progress). mn10300-elf.
2366 * REMOVED configurations and files
2368 VxWorks and the XDR protocol *-*-vxworks
2369 Motorola MCORE mcore-*-*
2370 National Semiconductor NS32000 ns32k-*-*
2372 * New "set print array-indexes" command
2374 After turning this setting "on", GDB prints the index of each element
2375 when displaying arrays. The default is "off" to preserve the previous
2378 * VAX floating point support
2380 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2382 * User-defined command support
2384 In addition to using $arg0..$arg9 for argument passing, it is now possible
2385 to use $argc to determine now many arguments have been passed. See the
2386 section on user-defined commands in the user manual for more information.
2388 *** Changes in GDB 6.3:
2390 * New command line option
2392 GDB now accepts -l followed by a number to set the timeout for remote
2395 * GDB works with GCC -feliminate-dwarf2-dups
2397 GDB now supports a more compact representation of DWARF-2 debug
2398 information using DW_FORM_ref_addr references. These are produced
2399 by GCC with the option -feliminate-dwarf2-dups and also by some
2400 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2401 to use -feliminate-dwarf2-dups.
2403 * Internationalization
2405 When supported by the host system, GDB will be built with
2406 internationalization (libintl). The task of marking up the sources is
2407 continued, we're looking forward to our first translation.
2411 Initial support for debugging programs compiled with the GNAT
2412 implementation of the Ada programming language has been integrated
2413 into GDB. In this release, support is limited to expression evaluation.
2415 * New native configurations
2417 GNU/Linux/m32r m32r-*-linux-gnu
2421 GDB's remote protocol now includes support for the 'p' packet. This
2422 packet is used to fetch individual registers from a remote inferior.
2424 * END-OF-LIFE registers[] compatibility module
2426 GDB's internal register infrastructure has been completely rewritten.
2427 The new infrastructure making possible the implementation of key new
2428 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2431 GDB 6.3 will be the last release to include the the registers[]
2432 compatibility module that allowed out-of-date configurations to
2433 continue to work. This change directly impacts the following
2443 powerpc bdm protocol
2445 Unless there is activity to revive these configurations, they will be
2446 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2448 * OBSOLETE configurations and files
2450 Configurations that have been declared obsolete in this release have
2451 been commented out. Unless there is activity to revive these
2452 configurations, the next release of GDB will have their sources
2453 permanently REMOVED.
2462 *** Changes in GDB 6.2.1:
2464 * MIPS `break main; run' gave an heuristic-fence-post warning
2466 When attempting to run even a simple program, a warning about
2467 heuristic-fence-post being hit would be reported. This problem has
2470 * MIPS IRIX 'long double' crashed GDB
2472 When examining a long double variable, GDB would get a segmentation
2473 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2474 IRIX long double values).
2478 A bug in the VAX stack code was causing problems with the "next"
2479 command. This problem has been fixed.
2481 *** Changes in GDB 6.2:
2483 * Fix for ``many threads''
2485 On GNU/Linux systems that use the NPTL threads library, a program
2486 rapidly creating and deleting threads would confuse GDB leading to the
2489 ptrace: No such process.
2490 thread_db_get_info: cannot get thread info: generic error
2492 This problem has been fixed.
2494 * "-async" and "-noasync" options removed.
2496 Support for the broken "-noasync" option has been removed (it caused
2499 * New ``start'' command.
2501 This command runs the program until the begining of the main procedure.
2503 * New BSD Kernel Data Access Library (libkvm) interface
2505 Using ``target kvm'' it is now possible to debug kernel core dumps and
2506 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2507 platforms. Currently supported (native-only) configurations are:
2509 FreeBSD/amd64 x86_64-*-freebsd*
2510 FreeBSD/i386 i?86-*-freebsd*
2511 NetBSD/i386 i?86-*-netbsd*
2512 NetBSD/m68k m68*-*-netbsd*
2513 NetBSD/sparc sparc-*-netbsd*
2514 OpenBSD/amd64 x86_64-*-openbsd*
2515 OpenBSD/i386 i?86-*-openbsd*
2516 OpenBSD/m68k m68*-openbsd*
2517 OpenBSD/sparc sparc-*-openbsd*
2519 * Signal trampoline code overhauled
2521 Many generic problems with GDB's signal handling code have been fixed.
2522 These include: backtraces through non-contiguous stacks; recognition
2523 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2524 call; backtrace through a signal trampoline; step into and out of
2525 signal handlers; and single-stepping in the signal trampoline.
2527 Please note that kernel bugs are a limiting factor here. These
2528 features have been shown to work on an s390 GNU/Linux system that
2529 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2531 * Cygwin support for DWARF 2 added.
2533 * New native configurations
2535 GNU/Linux/hppa hppa*-*-linux*
2536 OpenBSD/hppa hppa*-*-openbsd*
2537 OpenBSD/m68k m68*-*-openbsd*
2538 OpenBSD/m88k m88*-*-openbsd*
2539 OpenBSD/powerpc powerpc-*-openbsd*
2540 NetBSD/vax vax-*-netbsd*
2541 OpenBSD/vax vax-*-openbsd*
2543 * END-OF-LIFE frame compatibility module
2545 GDB's internal frame infrastructure has been completely rewritten.
2546 The new infrastructure making it possible to support key new features
2547 including DWARF 2 Call Frame Information. To aid in the task of
2548 migrating old configurations to this new infrastructure, a
2549 compatibility module, that allowed old configurations to continue to
2550 work, was also included.
2552 GDB 6.2 will be the last release to include this frame compatibility
2553 module. This change directly impacts the following configurations:
2563 Unless there is activity to revive these configurations, they will be
2564 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2566 * REMOVED configurations and files
2568 Sun 3, running SunOS 3 m68*-*-sunos3*
2569 Sun 3, running SunOS 4 m68*-*-sunos4*
2570 Sun 2, running SunOS 3 m68000-*-sunos3*
2571 Sun 2, running SunOS 4 m68000-*-sunos4*
2572 Motorola 680x0 running LynxOS m68*-*-lynxos*
2573 AT&T 3b1/Unix pc m68*-att-*
2574 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2575 decstation mips-dec-* mips-little-*
2576 riscos mips-*-riscos* mips-*-sysv*
2577 sonymips mips-sony-*
2578 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2580 *** Changes in GDB 6.1.1:
2582 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2584 The TUI (Text-mode User Interface) is now built as part of a default
2585 GDB configuration. It is enabled by either selecting the TUI with the
2586 command line option "-i=tui" or by running the separate "gdbtui"
2587 program. For more information on the TUI, see the manual "Debugging
2590 * Pending breakpoint support (also included in GDB 6.1)
2592 Support has been added to allow you to specify breakpoints in shared
2593 libraries that have not yet been loaded. If a breakpoint location
2594 cannot be found, and the "breakpoint pending" option is set to auto,
2595 GDB queries you if you wish to make the breakpoint pending on a future
2596 shared-library load. If and when GDB resolves the breakpoint symbol,
2597 the pending breakpoint is removed as one or more regular breakpoints
2600 Pending breakpoints are very useful for GCJ Java debugging.
2602 * Fixed ISO-C build problems
2604 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2605 non ISO-C code that stopped them being built using a more strict ISO-C
2606 compiler (e.g., IBM's C compiler).
2608 * Fixed build problem on IRIX 5
2610 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2611 wasn't able to compile compile on an IRIX 5 system.
2613 * Added execute permission to gdb/gdbserver/configure
2615 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2616 permission. This bug would cause configure to fail on a number of
2617 systems (Solaris, IRIX). Ref: server/519.
2619 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2621 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2622 has been updated to use constant array sizes.
2624 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2626 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2627 its generated DWARF Call Frame Info. This encoding was causing GDB to
2628 panic, that panic has been fixed. Ref: gdb/1628.
2630 * Fixed a problem when examining parameters in shared library code.
2632 When examining parameters in optimized shared library code generated
2633 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2634 not available''. GDB now correctly displays the variable's value.
2636 *** Changes in GDB 6.1:
2638 * Removed --with-mmalloc
2640 Support for the mmalloc memory manager has been removed, as it
2641 conflicted with the internal gdb byte cache.
2643 * Changes in AMD64 configurations
2645 The AMD64 target now includes the %cs and %ss registers. As a result
2646 the AMD64 remote protocol has changed; this affects the floating-point
2647 and SSE registers. If you rely on those registers for your debugging,
2648 you should upgrade gdbserver on the remote side.
2650 * Revised SPARC target
2652 The SPARC target has been completely revised, incorporating the
2653 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2654 support for LynxOS and SunOS 4 has been dropped. Calling functions
2655 from within GDB on operating systems with a non-executable stack
2656 (Solaris, OpenBSD) now works.
2660 GDB has a new C++ demangler which does a better job on the mangled
2661 names generated by current versions of g++. It also runs faster, so
2662 with this and other changes gdb should now start faster on large C++
2665 * DWARF 2 Location Expressions
2667 GDB support for location expressions has been extended to support function
2668 arguments and frame bases. Older versions of GDB could crash when they
2671 * C++ nested types and namespaces
2673 GDB's support for nested types and namespaces in C++ has been
2674 improved, especially if you use the DWARF 2 debugging format. (This
2675 is the default for recent versions of GCC on most platforms.)
2676 Specifically, if you have a class "Inner" defined within a class or
2677 namespace "Outer", then GDB realizes that the class's name is
2678 "Outer::Inner", not simply "Inner". This should greatly reduce the
2679 frequency of complaints about not finding RTTI symbols. In addition,
2680 if you are stopped at inside of a function defined within a namespace,
2681 GDB modifies its name lookup accordingly.
2683 * New native configurations
2685 NetBSD/amd64 x86_64-*-netbsd*
2686 OpenBSD/amd64 x86_64-*-openbsd*
2687 OpenBSD/alpha alpha*-*-openbsd*
2688 OpenBSD/sparc sparc-*-openbsd*
2689 OpenBSD/sparc64 sparc64-*-openbsd*
2691 * New debugging protocols
2693 M32R with SDI protocol m32r-*-elf*
2695 * "set prompt-escape-char" command deleted.
2697 The command "set prompt-escape-char" has been deleted. This command,
2698 and its very obscure effet on GDB's prompt, was never documented,
2699 tested, nor mentioned in the NEWS file.
2701 * OBSOLETE configurations and files
2703 Configurations that have been declared obsolete in this release have
2704 been commented out. Unless there is activity to revive these
2705 configurations, the next release of GDB will have their sources
2706 permanently REMOVED.
2708 Sun 3, running SunOS 3 m68*-*-sunos3*
2709 Sun 3, running SunOS 4 m68*-*-sunos4*
2710 Sun 2, running SunOS 3 m68000-*-sunos3*
2711 Sun 2, running SunOS 4 m68000-*-sunos4*
2712 Motorola 680x0 running LynxOS m68*-*-lynxos*
2713 AT&T 3b1/Unix pc m68*-att-*
2714 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2715 decstation mips-dec-* mips-little-*
2716 riscos mips-*-riscos* mips-*-sysv*
2717 sonymips mips-sony-*
2718 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2720 * REMOVED configurations and files
2722 SGI Irix-4.x mips-sgi-irix4 or iris4
2723 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2724 Z8000 simulator z8k-zilog-none or z8ksim
2725 Matsushita MN10200 w/simulator mn10200-*-*
2726 H8/500 simulator h8500-hitachi-hms or h8500hms
2727 HP/PA running BSD hppa*-*-bsd*
2728 HP/PA running OSF/1 hppa*-*-osf*
2729 HP/PA Pro target hppa*-*-pro*
2730 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2731 386BSD i[3456]86-*-bsd*
2732 Sequent family i[3456]86-sequent-sysv4*
2733 i[3456]86-sequent-sysv*
2734 i[3456]86-sequent-bsd*
2735 SPARC running LynxOS sparc-*-lynxos*
2736 SPARC running SunOS 4 sparc-*-sunos4*
2737 Tsqware Sparclet sparclet-*-*
2738 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2740 *** Changes in GDB 6.0:
2744 Support for debugging the Objective-C programming language has been
2745 integrated into GDB.
2747 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2749 DWARF 2's Call Frame Information makes available compiler generated
2750 information that more exactly describes the program's run-time stack.
2751 By using this information, GDB is able to provide more robust stack
2754 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2755 have been updated to use a new backtrace mechanism which includes
2756 DWARF 2 CFI support.
2760 GDB's remote protocol has been extended to include support for hosted
2761 file I/O (where the remote target uses GDB's file system). See GDB's
2762 remote protocol documentation for details.
2764 * All targets using the new architecture framework.
2766 All of GDB's targets have been updated to use the new internal
2767 architecture framework. The way is now open for future GDB releases
2768 to include cross-architecture native debugging support (i386 on amd64,
2771 * GNU/Linux's Thread Local Storage (TLS)
2773 GDB now includes support for for the GNU/Linux implementation of
2774 per-thread variables.
2776 * GNU/Linux's Native POSIX Thread Library (NPTL)
2778 GDB's thread code has been updated to work with either the new
2779 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2781 * Separate debug info.
2783 GDB, in conjunction with BINUTILS, now supports a mechanism for
2784 automatically loading debug information from a separate file. Instead
2785 of shipping full debug and non-debug versions of system libraries,
2786 system integrators can now instead ship just the stripped libraries
2787 and optional debug files.
2789 * DWARF 2 Location Expressions
2791 DWARF 2 Location Expressions allow the compiler to more completely
2792 describe the location of variables (even in optimized code) to the
2795 GDB now includes preliminary support for location expressions (support
2796 for DW_OP_piece is still missing).
2800 A number of long standing bugs that caused GDB to die while starting a
2801 Java application have been fixed. GDB's Java support is now
2802 considered "useable".
2804 * GNU/Linux support for fork, vfork, and exec.
2806 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2807 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2810 * GDB supports logging output to a file
2812 There are two new commands, "set logging" and "show logging", which can be
2813 used to capture GDB's output to a file.
2815 * The meaning of "detach" has changed for gdbserver
2817 The "detach" command will now resume the application, as documented. To
2818 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2821 * d10v, m68hc11 `regs' command deprecated
2823 The `info registers' command has been updated so that it displays the
2824 registers using a format identical to the old `regs' command.
2828 A new command, "maint set profile on/off", has been added. This command can
2829 be used to enable or disable profiling while running GDB, to profile a
2830 session or a set of commands. In addition there is a new configure switch,
2831 "--enable-profiling", which will cause GDB to be compiled with profiling
2832 data, for more informative profiling results.
2834 * Default MI syntax changed to "mi2".
2836 The default MI (machine interface) syntax, enabled by the command line
2837 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2838 "mi1", can be enabled by specifying the option "-i=mi1".
2840 Support for the original "mi0" syntax (included in GDB 5.0) has been
2843 Fix for gdb/192: removed extraneous space when displaying frame level.
2844 Fix for gdb/672: update changelist is now output in mi list format.
2845 Fix for gdb/702: a -var-assign that updates the value now shows up
2846 in a subsequent -var-update.
2848 * New native configurations.
2850 FreeBSD/amd64 x86_64-*-freebsd*
2852 * Multi-arched targets.
2854 HP/PA HPUX11 hppa*-*-hpux*
2855 Renesas M32R/D w/simulator m32r-*-elf*
2857 * OBSOLETE configurations and files
2859 Configurations that have been declared obsolete in this release have
2860 been commented out. Unless there is activity to revive these
2861 configurations, the next release of GDB will have their sources
2862 permanently REMOVED.
2864 Z8000 simulator z8k-zilog-none or z8ksim
2865 Matsushita MN10200 w/simulator mn10200-*-*
2866 H8/500 simulator h8500-hitachi-hms or h8500hms
2867 HP/PA running BSD hppa*-*-bsd*
2868 HP/PA running OSF/1 hppa*-*-osf*
2869 HP/PA Pro target hppa*-*-pro*
2870 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2871 Sequent family i[3456]86-sequent-sysv4*
2872 i[3456]86-sequent-sysv*
2873 i[3456]86-sequent-bsd*
2874 Tsqware Sparclet sparclet-*-*
2875 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2877 * REMOVED configurations and files
2880 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2881 IBM AIX PS/2 i[3456]86-*-aix
2882 i386 running Mach 3.0 i[3456]86-*-mach3*
2883 i386 running Mach i[3456]86-*-mach*
2884 i386 running OSF/1 i[3456]86-*osf1mk*
2885 HP/Apollo 68k Family m68*-apollo*-sysv*,
2887 m68*-hp-bsd*, m68*-hp-hpux*
2888 Argonaut Risc Chip (ARC) arc-*-*
2889 Mitsubishi D30V d30v-*-*
2890 Fujitsu FR30 fr30-*-elf*
2891 OS/9000 i[34]86-*-os9k
2892 I960 with MON960 i960-*-coff
2894 * MIPS $fp behavior changed
2896 The convenience variable $fp, for the MIPS, now consistently returns
2897 the address of the current frame's base. Previously, depending on the
2898 context, $fp could refer to either $sp or the current frame's base
2899 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2900 The GNU Source-Level Debugger''.
2902 *** Changes in GDB 5.3:
2904 * GNU/Linux shared library multi-threaded performance improved.
2906 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2907 `/proc', in preference to `ptrace' for memory reads. This may result
2908 in an improvement in the start-up time of multi-threaded, shared
2909 library applications when run under GDB. One GDB user writes: ``loads
2910 shared libs like mad''.
2912 * ``gdbserver'' now supports multi-threaded applications on some targets
2914 Support for debugging multi-threaded applications which use
2915 the GNU/Linux LinuxThreads package has been added for
2916 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2917 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2919 * GDB now supports C/C++ preprocessor macros.
2921 GDB now expands preprocessor macro invocations in C/C++ expressions,
2922 and provides various commands for showing macro definitions and how
2925 The new command `macro expand EXPRESSION' expands any macro
2926 invocations in expression, and shows the result.
2928 The new command `show macro MACRO-NAME' shows the definition of the
2929 macro named MACRO-NAME, and where it was defined.
2931 Most compilers don't include information about macros in the debugging
2932 information by default. In GCC 3.1, for example, you need to compile
2933 your program with the options `-gdwarf-2 -g3'. If the macro
2934 information is present in the executable, GDB will read it.
2936 * Multi-arched targets.
2938 DEC Alpha (partial) alpha*-*-*
2939 DEC VAX (partial) vax-*-*
2941 National Semiconductor NS32000 (partial) ns32k-*-*
2942 Motorola 68000 (partial) m68k-*-*
2943 Motorola MCORE mcore-*-*
2947 Fujitsu FRV architecture added by Red Hat frv*-*-*
2950 * New native configurations
2952 Alpha NetBSD alpha*-*-netbsd*
2953 SH NetBSD sh*-*-netbsdelf*
2954 MIPS NetBSD mips*-*-netbsd*
2955 UltraSPARC NetBSD sparc64-*-netbsd*
2957 * OBSOLETE configurations and files
2959 Configurations that have been declared obsolete in this release have
2960 been commented out. Unless there is activity to revive these
2961 configurations, the next release of GDB will have their sources
2962 permanently REMOVED.
2964 Mitsubishi D30V d30v-*-*
2965 OS/9000 i[34]86-*-os9k
2966 IBM AIX PS/2 i[3456]86-*-aix
2967 Fujitsu FR30 fr30-*-elf*
2968 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2969 Argonaut Risc Chip (ARC) arc-*-*
2970 i386 running Mach 3.0 i[3456]86-*-mach3*
2971 i386 running Mach i[3456]86-*-mach*
2972 i386 running OSF/1 i[3456]86-*osf1mk*
2973 HP/Apollo 68k Family m68*-apollo*-sysv*,
2975 m68*-hp-bsd*, m68*-hp-hpux*
2976 I960 with MON960 i960-*-coff
2978 * OBSOLETE languages
2980 CHILL, a Pascal like language used by telecommunications companies.
2982 * REMOVED configurations and files
2984 AMD 29k family via UDI a29k-amd-udi, udi29k
2985 A29K VxWorks a29k-*-vxworks
2986 AMD 29000 embedded, using EBMON a29k-none-none
2987 AMD 29000 embedded with COFF a29k-none-coff
2988 AMD 29000 embedded with a.out a29k-none-aout
2990 testsuite/gdb.hp/gdb.threads-hp/ directory
2992 * New command "set max-user-call-depth <nnn>"
2994 This command allows the user to limit the call depth of user-defined
2995 commands. The default is 1024.
2997 * Changes in FreeBSD/i386 native debugging.
2999 Support for the "generate-core-file" has been added.
3001 * New commands "dump", "append", and "restore".
3003 These commands allow data to be copied from target memory
3004 to a bfd-format or binary file (dump and append), and back
3005 from a file into memory (restore).
3007 * Improved "next/step" support on multi-processor Alpha Tru64.
3009 The previous single-step mechanism could cause unpredictable problems,
3010 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3011 of a software single-step mechanism prevents this.
3013 *** Changes in GDB 5.2.1:
3021 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3022 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3023 Fix, by Joel Brobecker imported from mainline.
3025 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3026 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3027 Fix, by Fred Fish, imported from mainline.
3029 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3030 Surprisingly enough, it works now.
3031 By Michal Ludvig, imported from mainline.
3033 i386 hardware watchpoint support:
3034 avoid misses on second run for some targets.
3035 By Pierre Muller, imported from mainline.
3037 *** Changes in GDB 5.2:
3039 * New command "set trust-readonly-sections on[off]".
3041 This command is a hint that tells gdb that read-only sections
3042 really are read-only (ie. that their contents will not change).
3043 In this mode, gdb will go to the object file rather than the
3044 target to read memory from read-only sections (such as ".text").
3045 This can be a significant performance improvement on some
3046 (notably embedded) targets.
3048 * New command "generate-core-file" (or "gcore").
3050 This new gdb command allows the user to drop a core file of the child
3051 process state at any time. So far it's been implemented only for
3052 GNU/Linux and Solaris, but should be relatively easily ported to other
3053 hosts. Argument is core file name (defaults to core.<pid>).
3055 * New command line option
3057 GDB now accepts --pid or -p followed by a process id.
3059 * Change in command line behavior -- corefiles vs. process ids.
3061 There is a subtle behavior in the way in which GDB handles
3062 command line arguments. The first non-flag argument is always
3063 a program to debug, but the second non-flag argument may either
3064 be a corefile or a process id. Previously, GDB would attempt to
3065 open the second argument as a corefile, and if that failed, would
3066 issue a superfluous error message and then attempt to attach it as
3067 a process. Now, if the second argument begins with a non-digit,
3068 it will be treated as a corefile. If it begins with a digit,
3069 GDB will attempt to attach it as a process, and if no such process
3070 is found, will then attempt to open it as a corefile.
3072 * Changes in ARM configurations.
3074 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3075 configuration is fully multi-arch.
3077 * New native configurations
3079 ARM NetBSD arm*-*-netbsd*
3080 x86 OpenBSD i[3456]86-*-openbsd*
3081 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3082 Sparc64 running FreeBSD sparc64-*-freebsd*
3086 Sanyo XStormy16 xstormy16-elf
3088 * OBSOLETE configurations and files
3090 Configurations that have been declared obsolete in this release have
3091 been commented out. Unless there is activity to revive these
3092 configurations, the next release of GDB will have their sources
3093 permanently REMOVED.
3095 AMD 29k family via UDI a29k-amd-udi, udi29k
3096 A29K VxWorks a29k-*-vxworks
3097 AMD 29000 embedded, using EBMON a29k-none-none
3098 AMD 29000 embedded with COFF a29k-none-coff
3099 AMD 29000 embedded with a.out a29k-none-aout
3101 testsuite/gdb.hp/gdb.threads-hp/ directory
3103 * REMOVED configurations and files
3105 TI TMS320C80 tic80-*-*
3107 PowerPC Solaris powerpcle-*-solaris*
3108 PowerPC Windows NT powerpcle-*-cygwin32
3109 PowerPC Netware powerpc-*-netware*
3110 Harris/CXUX m88k m88*-harris-cxux*
3111 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3112 ns32k-utek-sysv* ns32k-utek-*
3113 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3114 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3115 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3116 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3117 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3119 * Changes to command line processing
3121 The new `--args' feature can be used to specify command-line arguments
3122 for the inferior from gdb's command line.
3124 * Changes to key bindings
3126 There is a new `operate-and-get-next' function bound to `C-o'.
3128 *** Changes in GDB 5.1.1
3130 Fix compile problem on DJGPP.
3132 Fix a problem with floating-point registers on the i386 being
3135 Fix to stop GDB crashing on .debug_str debug info.
3137 Numerous documentation fixes.
3139 Numerous testsuite fixes.
3141 *** Changes in GDB 5.1:
3143 * New native configurations
3145 Alpha FreeBSD alpha*-*-freebsd*
3146 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3147 MIPS GNU/Linux mips*-*-linux*
3148 MIPS SGI Irix 6.x mips*-sgi-irix6*
3149 ia64 AIX ia64-*-aix*
3150 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3154 Motorola 68HC11 and 68HC12 m68hc11-elf
3156 UltraSparc running GNU/Linux sparc64-*-linux*
3158 * OBSOLETE configurations and files
3160 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3161 Harris/CXUX m88k m88*-harris-cxux*
3162 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3163 ns32k-utek-sysv* ns32k-utek-*
3164 TI TMS320C80 tic80-*-*
3166 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3167 PowerPC Solaris powerpcle-*-solaris*
3168 PowerPC Windows NT powerpcle-*-cygwin32
3169 PowerPC Netware powerpc-*-netware*
3170 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3171 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3172 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3173 Apple Macintosh (MPW) host N/A
3175 stuff.c (Program to stuff files into a specially prepared space in kdb)
3176 kdb-start.c (Main loop for the standalone kernel debugger)
3178 Configurations that have been declared obsolete in this release have
3179 been commented out. Unless there is activity to revive these
3180 configurations, the next release of GDB will have their sources
3181 permanently REMOVED.
3183 * REMOVED configurations and files
3185 Altos 3068 m68*-altos-*
3186 Convex c1-*-*, c2-*-*
3188 ARM RISCix arm-*-* (as host)
3192 * GDB has been converted to ISO C.
3194 GDB's source code has been converted to ISO C. In particular, the
3195 sources are fully protoized, and rely on standard headers being
3200 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3202 * The MI enabled by default.
3204 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3205 revised and enabled by default. Packages which use GDB as a debugging
3206 engine behind a UI or another front end are encouraged to switch to
3207 using the GDB/MI interface, instead of the old annotations interface
3208 which is now deprecated.
3210 * Support for debugging Pascal programs.
3212 GDB now includes support for debugging Pascal programs. The following
3213 main features are supported:
3215 - Pascal-specific data types such as sets;
3217 - automatic recognition of Pascal sources based on file-name
3220 - Pascal-style display of data types, variables, and functions;
3222 - a Pascal expression parser.
3224 However, some important features are not yet supported.
3226 - Pascal string operations are not supported at all;
3228 - there are some problems with boolean types;
3230 - Pascal type hexadecimal constants are not supported
3231 because they conflict with the internal variables format;
3233 - support for Pascal objects and classes is not full yet;
3235 - unlike Pascal, GDB is case-sensitive for symbol names.
3237 * Changes in completion.
3239 Commands such as `shell', `run' and `set args', which pass arguments
3240 to inferior programs, now complete on file names, similar to what
3241 users expect at the shell prompt.
3243 Commands which accept locations, such as `disassemble', `print',
3244 `breakpoint', `until', etc. now complete on filenames as well as
3245 program symbols. Thus, if you type "break foob TAB", and the source
3246 files linked into the programs include `foobar.c', that file name will
3247 be one of the candidates for completion. However, file names are not
3248 considered for completion after you typed a colon that delimits a file
3249 name from a name of a function in that file, as in "break foo.c:bar".
3251 `set demangle-style' completes on available demangling styles.
3253 * New platform-independent commands:
3255 It is now possible to define a post-hook for a command as well as a
3256 hook that runs before the command. For more details, see the
3257 documentation of `hookpost' in the GDB manual.
3259 * Changes in GNU/Linux native debugging.
3261 Support for debugging multi-threaded programs has been completely
3262 revised for all platforms except m68k and sparc. You can now debug as
3263 many threads as your system allows you to have.
3265 Attach/detach is supported for multi-threaded programs.
3267 Support for SSE registers was added for x86. This doesn't work for
3268 multi-threaded programs though.
3270 * Changes in MIPS configurations.
3272 Multi-arch support is enabled for all MIPS configurations.
3274 GDB can now be built as native debugger on SGI Irix 6.x systems for
3275 debugging n32 executables. (Debugging 64-bit executables is not yet
3278 * Unified support for hardware watchpoints in all x86 configurations.
3280 Most (if not all) native x86 configurations support hardware-assisted
3281 breakpoints and watchpoints in a unified manner. This support
3282 implements debug register sharing between watchpoints, which allows to
3283 put a virtually infinite number of watchpoints on the same address,
3284 and also supports watching regions up to 16 bytes with several debug
3287 The new maintenance command `maintenance show-debug-regs' toggles
3288 debugging print-outs in functions that insert, remove, and test
3289 watchpoints and hardware breakpoints.
3291 * Changes in the DJGPP native configuration.
3293 New command ``info dos sysinfo'' displays assorted information about
3294 the CPU, OS, memory, and DPMI server.
3296 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3297 display information about segment descriptors stored in GDT, LDT, and
3300 New commands ``info dos pde'' and ``info dos pte'' display entries
3301 from Page Directory and Page Tables (for now works with CWSDPMI only).
3302 New command ``info dos address-pte'' displays the Page Table entry for
3303 a given linear address.
3305 GDB can now pass command lines longer than 126 characters to the
3306 program being debugged (requires an update to the libdbg.a library
3307 which is part of the DJGPP development kit).
3309 DWARF2 debug info is now supported.
3311 It is now possible to `step' and `next' through calls to `longjmp'.
3313 * Changes in documentation.
3315 All GDB documentation was converted to GFDL, the GNU Free
3316 Documentation License.
3318 Tracepoints-related commands are now fully documented in the GDB
3321 TUI, the Text-mode User Interface, is now documented in the manual.
3323 Tracepoints-related commands are now fully documented in the GDB
3326 The "GDB Internals" manual now has an index. It also includes
3327 documentation of `ui_out' functions, GDB coding standards, x86
3328 hardware watchpoints, and memory region attributes.
3330 * GDB's version number moved to ``version.in''
3332 The Makefile variable VERSION has been replaced by the file
3333 ``version.in''. People creating GDB distributions should update the
3334 contents of this file.
3338 GUD support is now a standard part of the EMACS distribution.
3340 *** Changes in GDB 5.0:
3342 * Improved support for debugging FP programs on x86 targets
3344 Unified and much-improved support for debugging floating-point
3345 programs on all x86 targets. In particular, ``info float'' now
3346 displays the FP registers in the same format on all x86 targets, with
3347 greater level of detail.
3349 * Improvements and bugfixes in hardware-assisted watchpoints
3351 It is now possible to watch array elements, struct members, and
3352 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3353 on x86 targets no longer erroneously trigger when the address is
3356 * Improvements in the native DJGPP version of GDB
3358 The distribution now includes all the scripts and auxiliary files
3359 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3360 machines ``out of the box''.
3362 The DJGPP version can now debug programs that use signals. It is
3363 possible to catch signals that happened in the debuggee, deliver
3364 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3365 would kill the program being debugged.) Programs that hook hardware
3366 interrupts (keyboard, timer, etc.) can also be debugged.
3368 It is now possible to debug DJGPP programs that redirect their
3369 standard handles or switch them to raw (as opposed to cooked) mode, or
3370 even close them. The command ``run < foo > bar'' works as expected,
3371 and ``info terminal'' reports useful information about the debuggee's
3372 terminal, including raw/cooked mode, redirection, etc.
3374 The DJGPP version now uses termios functions for console I/O, which
3375 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3378 DOS-style file names with drive letters are now fully supported by
3381 It is now possible to debug DJGPP programs that switch their working
3382 directory. It is also possible to rerun the debuggee any number of
3383 times without restarting GDB; thus, you can use the same setup,
3384 breakpoints, etc. for many debugging sessions.
3386 * New native configurations
3388 ARM GNU/Linux arm*-*-linux*
3389 PowerPC GNU/Linux powerpc-*-linux*
3393 Motorola MCore mcore-*-*
3394 x86 VxWorks i[3456]86-*-vxworks*
3395 PowerPC VxWorks powerpc-*-vxworks*
3396 TI TMS320C80 tic80-*-*
3398 * OBSOLETE configurations
3400 Altos 3068 m68*-altos-*
3401 Convex c1-*-*, c2-*-*
3403 ARM RISCix arm-*-* (as host)
3406 Configurations that have been declared obsolete will be commented out,
3407 but the code will be left in place. If there is no activity to revive
3408 these configurations before the next release of GDB, the sources will
3409 be permanently REMOVED.
3411 * Gould support removed
3413 Support for the Gould PowerNode and NP1 has been removed.
3415 * New features for SVR4
3417 On SVR4 native platforms (such as Solaris), if you attach to a process
3418 without first loading a symbol file, GDB will now attempt to locate and
3419 load symbols from the running process's executable file.
3421 * Many C++ enhancements
3423 C++ support has been greatly improved. Overload resolution now works properly
3424 in almost all cases. RTTI support is on the way.
3426 * Remote targets can connect to a sub-program
3428 A popen(3) style serial-device has been added. This device starts a
3429 sub-process (such as a stand-alone simulator) and then communicates
3430 with that. The sub-program to run is specified using the syntax
3431 ``|<program> <args>'' vis:
3433 (gdb) set remotedebug 1
3434 (gdb) target extended-remote |mn10300-elf-sim program-args
3436 * MIPS 64 remote protocol
3438 A long standing bug in the mips64 remote protocol where by GDB
3439 expected certain 32 bit registers (ex SR) to be transfered as 32
3440 instead of 64 bits has been fixed.
3442 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3443 added to provide backward compatibility with older versions of GDB.
3445 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3447 The command ``set remotebinarydownload'' command has been replaced by
3448 ``set remote X-packet''. Other commands in ``set remote'' family
3449 include ``set remote P-packet''.
3451 * Breakpoint commands accept ranges.
3453 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3454 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3455 ``tracepoint passcount'' also accepts a range of tracepoints.
3457 * ``apropos'' command added.
3459 The ``apropos'' command searches through command names and
3460 documentation strings, printing out matches, making it much easier to
3461 try to find a command that does what you are looking for.
3465 A new machine oriented interface (MI) has been added to GDB. This
3466 interface is designed for debug environments running GDB as a separate
3467 process. This is part of the long term libGDB project. See the
3468 "GDB/MI" chapter of the GDB manual for further information. It can be
3469 enabled by configuring with:
3471 .../configure --enable-gdbmi
3473 *** Changes in GDB-4.18:
3475 * New native configurations
3477 HP-UX 10.20 hppa*-*-hpux10.20
3478 HP-UX 11.x hppa*-*-hpux11.0*
3479 M68K GNU/Linux m68*-*-linux*
3483 Fujitsu FR30 fr30-*-elf*
3484 Intel StrongARM strongarm-*-*
3485 Mitsubishi D30V d30v-*-*
3487 * OBSOLETE configurations
3489 Gould PowerNode, NP1 np1-*-*, pn-*-*
3491 Configurations that have been declared obsolete will be commented out,
3492 but the code will be left in place. If there is no activity to revive
3493 these configurations before the next release of GDB, the sources will
3494 be permanently REMOVED.
3498 As a compatibility experiment, GDB's source files buildsym.h and
3499 buildsym.c have been converted to pure standard C, no longer
3500 containing any K&R compatibility code. We believe that all systems in
3501 use today either come with a standard C compiler, or have a GCC port
3502 available. If this is not true, please report the affected
3503 configuration to bug-gdb@gnu.org immediately. See the README file for
3504 information about getting a standard C compiler if you don't have one
3509 GDB now uses readline 2.2.
3511 * set extension-language
3513 You can now control the mapping between filename extensions and source
3514 languages by using the `set extension-language' command. For instance,
3515 you can ask GDB to treat .c files as C++ by saying
3516 set extension-language .c c++
3517 The command `info extensions' lists all of the recognized extensions
3518 and their associated languages.
3520 * Setting processor type for PowerPC and RS/6000
3522 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3523 you can use the `set processor' command to specify what variant of the
3524 PowerPC family you are debugging. The command
3528 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3529 following PowerPC and RS6000 variants:
3531 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3532 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3534 403GC IBM PowerPC 403GC
3535 505 Motorola PowerPC 505
3536 860 Motorola PowerPC 860 or 850
3537 601 Motorola PowerPC 601
3538 602 Motorola PowerPC 602
3539 603 Motorola/IBM PowerPC 603 or 603e
3540 604 Motorola PowerPC 604 or 604e
3541 750 Motorola/IBM PowerPC 750 or 750
3543 At the moment, this command just tells GDB what to name the
3544 special-purpose processor registers. Since almost all the affected
3545 registers are inaccessible to user-level programs, this command is
3546 only useful for remote debugging in its present form.
3550 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3551 more extensive support for HP-UX. Added features include shared
3552 library support, kernel threads and hardware watchpoints for 11.00,
3553 support for HP's ANSI C and C++ compilers, and a compatibility mode
3554 for xdb and dbx commands.
3558 HP's donation includes the new concept of catchpoints, which is a
3559 generalization of the old catch command. On HP-UX, it is now possible
3560 to catch exec, fork, and vfork, as well as library loading.
3562 This means that the existing catch command has changed; its first
3563 argument now specifies the type of catch to be set up. See the
3564 output of "help catch" for a list of catchpoint types.
3566 * Debugging across forks
3568 On HP-UX, you can choose which process to debug when a fork() happens
3573 HP has donated a curses-based terminal user interface (TUI). To get
3574 it, build with --enable-tui. Although this can be enabled for any
3575 configuration, at present it only works for native HP debugging.
3577 * GDB remote protocol additions
3579 A new protocol packet 'X' that writes binary data is now available.
3580 Default behavior is to try 'X', then drop back to 'M' if the stub
3581 fails to respond. The settable variable `remotebinarydownload'
3582 allows explicit control over the use of 'X'.
3584 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3585 full 64-bit address. The command
3587 set remoteaddresssize 32
3589 can be used to revert to the old behaviour. For existing remote stubs
3590 the change should not be noticed, as the additional address information
3593 In order to assist in debugging stubs, you may use the maintenance
3594 command `packet' to send any text string to the stub. For instance,
3596 maint packet heythere
3598 sends the packet "$heythere#<checksum>". Note that it is very easy to
3599 disrupt a debugging session by sending the wrong packet at the wrong
3602 The compare-sections command allows you to compare section data on the
3603 target to what is in the executable file without uploading or
3604 downloading, by comparing CRC checksums.
3606 * Tracing can collect general expressions
3608 You may now collect general expressions at tracepoints. This requires
3609 further additions to the target-side stub; see tracepoint.c and
3610 doc/agentexpr.texi for further details.
3612 * mask-address variable for Mips
3614 For Mips targets, you may control the zeroing of the upper 32 bits of
3615 a 64-bit address by entering `set mask-address on'. This is mainly
3616 of interest to users of embedded R4xxx and R5xxx processors.
3618 * Higher serial baud rates
3620 GDB's serial code now allows you to specify baud rates 57600, 115200,
3621 230400, and 460800 baud. (Note that your host system may not be able
3622 to achieve all of these rates.)
3626 The i960 configuration now includes an initial implementation of a
3627 builtin simulator, contributed by Jim Wilson.
3630 *** Changes in GDB-4.17:
3632 * New native configurations
3634 Alpha GNU/Linux alpha*-*-linux*
3635 Unixware 2.x i[3456]86-unixware2*
3636 Irix 6.x mips*-sgi-irix6*
3637 PowerPC GNU/Linux powerpc-*-linux*
3638 PowerPC Solaris powerpcle-*-solaris*
3639 Sparc GNU/Linux sparc-*-linux*
3640 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3644 Argonaut Risc Chip (ARC) arc-*-*
3645 Hitachi H8/300S h8300*-*-*
3646 Matsushita MN10200 w/simulator mn10200-*-*
3647 Matsushita MN10300 w/simulator mn10300-*-*
3648 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3649 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3650 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3651 Mitsubishi D10V w/simulator d10v-*-*
3652 Mitsubishi M32R/D w/simulator m32r-*-elf*
3653 Tsqware Sparclet sparclet-*-*
3654 NEC V850 w/simulator v850-*-*
3656 * New debugging protocols
3658 ARM with RDI protocol arm*-*-*
3659 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3660 DDB and LSI variants of PMON protocol mips*-*-*
3661 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3662 PowerPC with SDS protocol powerpc{,le}-*-eabi
3663 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3667 All configurations can now understand and use the DWARF 2 debugging
3668 format. The choice is automatic, if the symbol file contains DWARF 2
3673 GDB now includes basic Java language support. This support is
3674 only useful with Java compilers that produce native machine code.
3676 * solib-absolute-prefix and solib-search-path
3678 For SunOS and SVR4 shared libraries, you may now set the prefix for
3679 loading absolute shared library symbol files, and the search path for
3680 locating non-absolute shared library symbol files.
3682 * Live range splitting
3684 GDB can now effectively debug code for which GCC has performed live
3685 range splitting as part of its optimization. See gdb/doc/LRS for
3686 more details on the expected format of the stabs information.
3690 GDB's support for the GNU Hurd, including thread debugging, has been
3691 updated to work with current versions of the Hurd.
3695 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3696 instruction set. ARM GDB automatically detects when Thumb
3697 instructions are in use, and adjusts disassembly and backtracing
3702 GDB's MIPS target configurations now handle the MIP16 16-bit
3707 GDB now includes support for overlays; if an executable has been
3708 linked such that multiple sections are based at the same address, GDB
3709 will decide which section to use for symbolic info. You can choose to
3710 control the decision manually, using overlay commands, or implement
3711 additional target-side support and use "overlay load-target" to bring
3712 in the overlay mapping. Do "help overlay" for more detail.
3716 The command "info symbol <address>" displays information about
3717 the symbol at the specified address.
3721 The standard remote protocol now includes an extension that allows
3722 asynchronous collection and display of trace data. This requires
3723 extensive support in the target-side debugging stub. Tracing mode
3724 includes a new interaction mode in GDB and new commands: see the
3725 file tracepoint.c for more details.
3729 Configurations for embedded MIPS now include a simulator contributed
3730 by Cygnus Solutions. The simulator supports the instruction sets
3731 of most MIPS variants.
3735 Sparc configurations may now include the ERC32 simulator contributed
3736 by the European Space Agency. The simulator is not built into
3737 Sparc targets by default; configure with --enable-sim to include it.
3741 For target configurations that may include multiple variants of a
3742 basic architecture (such as MIPS and SH), you may now set the
3743 architecture explicitly. "set arch" sets, "info arch" lists
3744 the possible architectures.
3746 *** Changes in GDB-4.16:
3748 * New native configurations
3750 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3751 M68K NetBSD m68k-*-netbsd*
3752 PowerPC AIX 4.x powerpc-*-aix*
3753 PowerPC MacOS powerpc-*-macos*
3754 PowerPC Windows NT powerpcle-*-cygwin32
3755 RS/6000 AIX 4.x rs6000-*-aix4*
3759 ARM with RDP protocol arm-*-*
3760 I960 with MON960 i960-*-coff
3761 MIPS VxWorks mips*-*-vxworks*
3762 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3763 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3765 Matra Sparclet sparclet-*-*
3769 The powerpc-eabi configuration now includes the PSIM simulator,
3770 contributed by Andrew Cagney, with assistance from Mike Meissner.
3771 PSIM is a very elaborate model of the PowerPC, including not only
3772 basic instruction set execution, but also details of execution unit
3773 performance and I/O hardware. See sim/ppc/README for more details.
3777 GDB now works with Solaris 2.5.
3779 * Windows 95/NT native
3781 GDB will now work as a native debugger on Windows 95 and Windows NT.
3782 To build it from source, you must use the "gnu-win32" environment,
3783 which uses a DLL to emulate enough of Unix to run the GNU tools.
3784 Further information, binaries, and sources are available at
3785 ftp.cygnus.com, under pub/gnu-win32.
3787 * dont-repeat command
3789 If a user-defined command includes the command `dont-repeat', then the
3790 command will not be repeated if the user just types return. This is
3791 useful if the command is time-consuming to run, so that accidental
3792 extra keystrokes don't run the same command many times.
3794 * Send break instead of ^C
3796 The standard remote protocol now includes an option to send a break
3797 rather than a ^C to the target in order to interrupt it. By default,
3798 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3800 * Remote protocol timeout
3802 The standard remote protocol includes a new variable `remotetimeout'
3803 that allows you to set the number of seconds before GDB gives up trying
3804 to read from the target. The default value is 2.
3806 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3808 By default GDB will automatically keep track of objects as they are
3809 loaded and unloaded by the dynamic linker. By using the command `set
3810 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3811 when shared library events occur, thus allowing you to set breakpoints
3812 in shared libraries which are explicitly loaded by the inferior.
3814 Note this feature does not work on hpux8. On hpux9 you must link
3815 /usr/lib/end.o into your program. This feature should work
3816 automatically on hpux10.
3818 * Irix 5.x hardware watchpoint support
3820 Irix 5 configurations now support the use of hardware watchpoints.
3822 * Mips protocol "SYN garbage limit"
3824 When debugging a Mips target using the `target mips' protocol, you
3825 may set the number of characters that GDB will ignore by setting
3826 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3827 every character. The default value is 1050.
3829 * Recording and replaying remote debug sessions
3831 If you set `remotelogfile' to the name of a file, gdb will write to it
3832 a recording of a remote debug session. This recording may then be
3833 replayed back to gdb using "gdbreplay". See gdbserver/README for
3834 details. This is useful when you have a problem with GDB while doing
3835 remote debugging; you can make a recording of the session and send it
3836 to someone else, who can then recreate the problem.
3838 * Speedups for remote debugging
3840 GDB includes speedups for downloading and stepping MIPS systems using
3841 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3842 and more efficient S-record downloading.
3844 * Memory use reductions and statistics collection
3846 GDB now uses less memory and reports statistics about memory usage.
3847 Try the `maint print statistics' command, for example.
3849 *** Changes in GDB-4.15:
3851 * Psymtabs for XCOFF
3853 The symbol reader for AIX GDB now uses partial symbol tables. This
3854 can greatly improve startup time, especially for large executables.
3856 * Remote targets use caching
3858 Remote targets now use a data cache to speed up communication with the
3859 remote side. The data cache could lead to incorrect results because
3860 it doesn't know about volatile variables, thus making it impossible to
3861 debug targets which use memory mapped I/O devices. `set remotecache
3862 off' turns the the data cache off.
3864 * Remote targets may have threads
3866 The standard remote protocol now includes support for multiple threads
3867 in the target system, using new protocol commands 'H' and 'T'. See
3868 gdb/remote.c for details.
3872 If GDB is configured with `--enable-netrom', then it will include
3873 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3874 acts as though it is a bank of ROM on the target board, but you can
3875 write into it over the network. GDB's support consists only of
3876 support for fast loading into the emulated ROM; to debug, you must use
3877 another protocol, such as standard remote protocol. The usual
3878 sequence is something like
3880 target nrom <netrom-hostname>
3882 target remote <netrom-hostname>:1235
3886 GDB now includes support for the Apple Macintosh, as a host only. It
3887 may be run as either an MPW tool or as a standalone application, and
3888 it can debug through the serial port. All the usual GDB commands are
3889 available, but to the target command, you must supply "serial" as the
3890 device type instead of "/dev/ttyXX". See mpw-README in the main
3891 directory for more information on how to build. The MPW configuration
3892 scripts */mpw-config.in support only a few targets, and only the
3893 mips-idt-ecoff target has been tested.
3897 GDB configuration now uses autoconf. This is not user-visible,
3898 but does simplify configuration and building.
3902 GDB now supports hpux10.
3904 *** Changes in GDB-4.14:
3906 * New native configurations
3908 x86 FreeBSD i[345]86-*-freebsd
3909 x86 NetBSD i[345]86-*-netbsd
3910 NS32k NetBSD ns32k-*-netbsd
3911 Sparc NetBSD sparc-*-netbsd
3915 A29K VxWorks a29k-*-vxworks
3916 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3917 CPU32 EST-300 emulator m68*-*-est*
3918 PowerPC ELF powerpc-*-elf
3921 * Alpha OSF/1 support for procfs
3923 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3924 possible to attach to running processes. As the mounting of the /proc
3925 filesystem is optional on the Alpha, GDB automatically determines
3926 the availability of /proc during startup. This can lead to problems
3927 if /proc is unmounted after GDB has been started.
3929 * Arguments to user-defined commands
3931 User commands may accept up to 10 arguments separated by whitespace.
3932 Arguments are accessed within the user command via $arg0..$arg9. A
3935 print $arg0 + $arg1 + $arg2
3937 To execute the command use:
3940 Defines the command "adder" which prints the sum of its three arguments.
3941 Note the arguments are text substitutions, so they may reference variables,
3942 use complex expressions, or even perform inferior function calls.
3944 * New `if' and `while' commands
3946 This makes it possible to write more sophisticated user-defined
3947 commands. Both commands take a single argument, which is the
3948 expression to evaluate, and must be followed by the commands to
3949 execute, one per line, if the expression is nonzero, the list being
3950 terminated by the word `end'. The `if' command list may include an
3951 `else' word, which causes the following commands to be executed only
3952 if the expression is zero.
3954 * Fortran source language mode
3956 GDB now includes partial support for Fortran 77. It will recognize
3957 Fortran programs and can evaluate a subset of Fortran expressions, but
3958 variables and functions may not be handled correctly. GDB will work
3959 with G77, but does not yet know much about symbols emitted by other
3962 * Better HPUX support
3964 Most debugging facilities now work on dynamic executables for HPPAs
3965 running hpux9 or later. You can attach to running dynamically linked
3966 processes, but by default the dynamic libraries will be read-only, so
3967 for instance you won't be able to put breakpoints in them. To change
3968 that behavior do the following before running the program:
3974 This will cause the libraries to be mapped private and read-write.
3975 To revert to the normal behavior, do this:
3981 You cannot set breakpoints or examine data in the library until after
3982 the library is loaded if the function/data symbols do not have
3985 GDB can now also read debug symbols produced by the HP C compiler on
3986 HPPAs (sorry, no C++, Fortran or 68k support).
3988 * Target byte order now dynamically selectable
3990 You can choose which byte order to use with a target system, via the
3991 commands "set endian big" and "set endian little", and you can see the
3992 current setting by using "show endian". You can also give the command
3993 "set endian auto", in which case GDB will use the byte order
3994 associated with the executable. Currently, only embedded MIPS
3995 configurations support dynamic selection of target byte order.
3997 * New DOS host serial code
3999 This version uses DPMI interrupts to handle buffered I/O, so you
4000 no longer need to run asynctsr when debugging boards connected to
4003 *** Changes in GDB-4.13:
4005 * New "complete" command
4007 This lists all the possible completions for the rest of the line, if it
4008 were to be given as a command itself. This is intended for use by emacs.
4010 * Trailing space optional in prompt
4012 "set prompt" no longer adds a space for you after the prompt you set. This
4013 allows you to set a prompt which ends in a space or one that does not.
4015 * Breakpoint hit counts
4017 "info break" now displays a count of the number of times the breakpoint
4018 has been hit. This is especially useful in conjunction with "ignore"; you
4019 can ignore a large number of breakpoint hits, look at the breakpoint info
4020 to see how many times the breakpoint was hit, then run again, ignoring one
4021 less than that number, and this will get you quickly to the last hit of
4024 * Ability to stop printing at NULL character
4026 "set print null-stop" will cause GDB to stop printing the characters of
4027 an array when the first NULL is encountered. This is useful when large
4028 arrays actually contain only short strings.
4030 * Shared library breakpoints
4032 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4033 breakpoints in shared libraries before the executable is run.
4035 * Hardware watchpoints
4037 There is a new hardware breakpoint for the watch command for sparclite
4038 targets. See gdb/sparclite/hw_breakpoint.note.
4040 Hardware watchpoints are also now supported under GNU/Linux.
4044 Annotations have been added. These are for use with graphical interfaces,
4045 and are still experimental. Currently only gdba.el uses these.
4047 * Improved Irix 5 support
4049 GDB now works properly with Irix 5.2.
4051 * Improved HPPA support
4053 GDB now works properly with the latest GCC and GAS.
4055 * New native configurations
4057 Sequent PTX4 i[34]86-sequent-ptx4
4058 HPPA running OSF/1 hppa*-*-osf*
4059 Atari TT running SVR4 m68*-*-sysv4*
4060 RS/6000 LynxOS rs6000-*-lynxos*
4064 OS/9000 i[34]86-*-os9k
4065 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4068 * Hitachi SH7000 and E7000-PC ICE support
4070 There is now support for communicating with the Hitachi E7000-PC ICE.
4071 This is available automatically when GDB is configured for the SH.
4075 As usual, a variety of small fixes and improvements, both generic
4076 and configuration-specific. See the ChangeLog for more detail.
4078 *** Changes in GDB-4.12:
4080 * Irix 5 is now supported
4084 GDB-4.12 on the HPPA has a number of changes which make it unable
4085 to debug the output from the currently released versions of GCC and
4086 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4087 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4088 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4091 *** Changes in GDB-4.11:
4093 * User visible changes:
4097 The "set remotedebug" option is now consistent between the mips remote
4098 target, remote targets using the gdb-specific protocol, UDI (AMD's
4099 debug protocol for the 29k) and the 88k bug monitor. It is now an
4100 integer specifying a debug level (normally 0 or 1, but 2 means more
4101 debugging info for the mips target).
4103 * DEC Alpha native support
4105 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4106 debug info, but GDB works fairly well with the DEC compiler and should
4107 work with a future GCC release. See the README file for a few
4108 Alpha-specific notes.
4110 * Preliminary thread implementation
4112 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4114 * LynxOS native and target support for 386
4116 This release has been hosted on LynxOS 2.2, and also can be configured
4117 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4120 * Improvements in C++ mangling/demangling.
4122 This release has much better g++ debugging, specifically in name
4123 mangling/demangling, virtual function calls, print virtual table,
4124 call methods, ...etc.
4126 *** Changes in GDB-4.10:
4128 * User visible changes:
4130 Remote debugging using the GDB-specific (`target remote') protocol now
4131 supports the `load' command. This is only useful if you have some
4132 other way of getting the stub to the target system, and you can put it
4133 somewhere in memory where it won't get clobbered by the download.
4135 Filename completion now works.
4137 When run under emacs mode, the "info line" command now causes the
4138 arrow to point to the line specified. Also, "info line" prints
4139 addresses in symbolic form (as well as hex).
4141 All vxworks based targets now support a user settable option, called
4142 vxworks-timeout. This option represents the number of seconds gdb
4143 should wait for responses to rpc's. You might want to use this if
4144 your vxworks target is, perhaps, a slow software simulator or happens
4145 to be on the far side of a thin network line.
4149 This release contains support for using a DEC alpha as a GDB host for
4150 cross debugging. Native alpha debugging is not supported yet.
4153 *** Changes in GDB-4.9:
4157 This is the first GDB release which is accompanied by a matching testsuite.
4158 The testsuite requires installation of dejagnu, which should be available
4159 via ftp from most sites that carry GNU software.
4163 'Cfront' style demangling has had its name changed to 'ARM' style, to
4164 emphasize that it was written from the specifications in the C++ Annotated
4165 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4166 disclaimers, it still generated too much confusion with users attempting to
4167 use gdb with AT&T cfront.
4171 GDB now uses a standard remote interface to a simulator library.
4172 So far, the library contains simulators for the Zilog Z8001/2, the
4173 Hitachi H8/300, H8/500 and Super-H.
4175 * New targets supported
4177 H8/300 simulator h8300-hitachi-hms or h8300hms
4178 H8/500 simulator h8500-hitachi-hms or h8500hms
4179 SH simulator sh-hitachi-hms or sh
4180 Z8000 simulator z8k-zilog-none or z8ksim
4181 IDT MIPS board over serial line mips-idt-ecoff
4183 Cross-debugging to GO32 targets is supported. It requires a custom
4184 version of the i386-stub.c module which is integrated with the
4185 GO32 memory extender.
4187 * New remote protocols
4189 MIPS remote debugging protocol.
4191 * New source languages supported
4193 This version includes preliminary support for Chill, a Pascal like language
4194 used by telecommunications companies. Chill support is also being integrated
4195 into the GNU compiler, but we don't know when it will be publically available.
4198 *** Changes in GDB-4.8:
4200 * HP Precision Architecture supported
4202 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4203 version of this support was available as a set of patches from the
4204 University of Utah. GDB does not support debugging of programs
4205 compiled with the HP compiler, because HP will not document their file
4206 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4207 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4209 Many problems in the preliminary version have been fixed.
4211 * Faster and better demangling
4213 We have improved template demangling and fixed numerous bugs in the GNU style
4214 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4215 character types (wchar_t) are now supported. Demangling of each symbol is now
4216 only done once, and is cached when the symbol table for a file is read in.
4217 This results in a small increase in memory usage for C programs, a moderate
4218 increase in memory usage for C++ programs, and a fantastic speedup in
4221 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4222 from the specifications in the Annotated Reference Manual, which AT&T's
4223 compiler does not actually implement.
4225 * G++ multiple inheritance compiler problem
4227 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4228 inheritance lattices was reworked to properly discover ambiguities. We
4229 recently found an example which causes this new algorithm to fail in a
4230 very subtle way, producing bad debug information for those classes.
4231 The file 'gcc.patch' (in this directory) can be applied to gcc to
4232 circumvent the problem. A future GCC release will contain a complete
4235 The previous G++ debug info problem (mentioned below for the gdb-4.7
4236 release) is fixed in gcc version 2.3.2.
4238 * Improved configure script
4240 The `configure' script will now attempt to guess your system type if
4241 you don't supply a host system type. The old scheme of supplying a
4242 host system triplet is preferable over using this. All the magic is
4243 done in the new `config.guess' script. Examine it for details.
4245 We have also brought our configure script much more in line with the FSF's
4246 version. It now supports the --with-xxx options. In particular,
4247 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4248 The resulting GDB will not be able to read arbitrary object file formats --
4249 only the format ``expected'' to be used on the configured target system.
4250 We hope to make this the default in a future release.
4252 * Documentation improvements
4254 There's new internal documentation on how to modify GDB, and how to
4255 produce clean changes to the code. We implore people to read it
4256 before submitting changes.
4258 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4259 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4260 `info' files are also provided. To build `info' files from scratch,
4261 you will need the latest `makeinfo' release, which will be available in
4262 a future texinfo-X.Y release.
4264 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4265 We're not sure exactly which versions have this problem, but it has
4266 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4267 or better. If that isn't possible, there is a patch in
4268 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4269 around this problem.
4273 GDB now supports array constants that can be used in expressions typed in by
4274 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4275 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4278 The new directory `gdb/sparclite' contains a program that demonstrates
4279 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4281 * New native hosts supported
4283 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4284 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4286 * New targets supported
4288 AMD 29k family via UDI a29k-amd-udi or udi29k
4290 * New file formats supported
4292 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4293 HPUX core files, and SCO 3.2v2 core files.
4297 Attaching to processes now works again; thanks for the many bug reports.
4299 We have also stomped on a bunch of core dumps caused by
4300 printf_filtered("%s") problems.
4302 We eliminated a copyright problem on the rpc and ptrace header files
4303 for VxWorks, which was discovered at the last minute during the 4.7
4304 release. You should now be able to build a VxWorks GDB.
4306 You can now interrupt gdb while an attached process is running. This
4307 will cause the attached process to stop, and give control back to GDB.
4309 We fixed problems caused by using too many file descriptors
4310 for reading symbols from object files and libraries. This was
4311 especially a problem for programs that used many (~100) shared
4314 The `step' command now only enters a subroutine if there is line number
4315 information for the subroutine. Otherwise it acts like the `next'
4316 command. Previously, `step' would enter subroutines if there was
4317 any debugging information about the routine. This avoids problems
4318 when using `cc -g1' on MIPS machines.
4320 * Internal improvements
4322 GDB's internal interfaces have been improved to make it easier to support
4323 debugging of multiple languages in the future.
4325 GDB now uses a common structure for symbol information internally.
4326 Minimal symbols (derived from linkage symbols in object files), partial
4327 symbols (from a quick scan of debug information), and full symbols
4328 contain a common subset of information, making it easier to write
4329 shared code that handles any of them.
4331 * New command line options
4333 We now accept --silent as an alias for --quiet.
4337 The memory-mapped-malloc library is now licensed under the GNU Library
4338 General Public License.
4340 *** Changes in GDB-4.7:
4342 * Host/native/target split
4344 GDB has had some major internal surgery to untangle the support for
4345 hosts and remote targets. Now, when you configure GDB for a remote
4346 target, it will no longer load in all of the support for debugging
4347 local programs on the host. When fully completed and tested, this will
4348 ensure that arbitrary host/target combinations are possible.
4350 The primary conceptual shift is to separate the non-portable code in
4351 GDB into three categories. Host specific code is required any time GDB
4352 is compiled on that host, regardless of the target. Target specific
4353 code relates to the peculiarities of the target, but can be compiled on
4354 any host. Native specific code is everything else: it can only be
4355 built when the host and target are the same system. Child process
4356 handling and core file support are two common `native' examples.
4358 GDB's use of /proc for controlling Unix child processes is now cleaner.
4359 It has been split out into a single module under the `target_ops' vector,
4360 plus two native-dependent functions for each system that uses /proc.
4362 * New hosts supported
4364 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4365 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4366 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4368 * New targets supported
4370 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4371 68030 and CPU32 m68030-*-*, m68332-*-*
4373 * New native hosts supported
4375 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4376 (386bsd is not well tested yet)
4377 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4379 * New file formats supported
4381 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4382 supports reading of `a.out.adobe' object files, which are an a.out
4383 format extended with minimal information about multiple sections.
4387 `show copying' is the same as the old `info copying'.
4388 `show warranty' is the same as `info warrantee'.
4389 These were renamed for consistency. The old commands continue to work.
4391 `info handle' is a new alias for `info signals'.
4393 You can now define pre-command hooks, which attach arbitrary command
4394 scripts to any command. The commands in the hook will be executed
4395 prior to the user's command. You can also create a hook which will be
4396 executed whenever the program stops. See gdb.texinfo.
4400 We now deal with Cfront style name mangling, and can even extract type
4401 info from mangled symbols. GDB can automatically figure out which
4402 symbol mangling style your C++ compiler uses.
4404 Calling of methods and virtual functions has been improved as well.
4408 The crash that occured when debugging Sun Ansi-C compiled binaries is
4409 fixed. This was due to mishandling of the extra N_SO stabs output
4412 We also finally got Ultrix 4.2 running in house, and fixed core file
4413 support, with help from a dozen people on the net.
4415 John M. Farrell discovered that the reason that single-stepping was so
4416 slow on all of the Mips based platforms (primarily SGI and DEC) was
4417 that we were trying to demangle and lookup a symbol used for internal
4418 purposes on every instruction that was being stepped through. Changing
4419 the name of that symbol so that it couldn't be mistaken for a C++
4420 mangled symbol sped things up a great deal.
4422 Rich Pixley sped up symbol lookups in general by getting much smarter
4423 about when C++ symbol mangling is necessary. This should make symbol
4424 completion (TAB on the command line) much faster. It's not as fast as
4425 we'd like, but it's significantly faster than gdb-4.6.
4429 A new user controllable variable 'call_scratch_address' can
4430 specify the location of a scratch area to be used when GDB
4431 calls a function in the target. This is necessary because the
4432 usual method of putting the scratch area on the stack does not work
4433 in systems that have separate instruction and data spaces.
4435 We integrated changes to support the 29k UDI (Universal Debugger
4436 Interface), but discovered at the last minute that we didn't have all
4437 of the appropriate copyright paperwork. We are working with AMD to
4438 resolve this, and hope to have it available soon.
4442 We have sped up the remote serial line protocol, especially for targets
4443 with lots of registers. It now supports a new `expedited status' ('T')
4444 message which can be used in place of the existing 'S' status message.
4445 This allows the remote stub to send only the registers that GDB
4446 needs to make a quick decision about single-stepping or conditional
4447 breakpoints, eliminating the need to fetch the entire register set for
4448 each instruction being stepped through.
4450 The GDB remote serial protocol now implements a write-through cache for
4451 registers, only re-reading the registers if the target has run.
4453 There is also a new remote serial stub for SPARC processors. You can
4454 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4455 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4456 processor with a serial port.
4460 Configure.in files have become much easier to read and modify. A new
4461 `table driven' format makes it more obvious what configurations are
4462 supported, and what files each one uses.
4466 There is a new opcodes library which will eventually contain all of the
4467 disassembly routines and opcode tables. At present, it only contains
4468 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4469 disassembler (binutils/objdump) to share these routines.
4471 The libiberty library is now copylefted under the GNU Library General
4472 Public License. This allows more liberal use, and was done so libg++
4473 can use it. This makes no difference to GDB, since the Library License
4474 grants all the rights from the General Public License.
4478 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4479 reference to the stabs symbol info used by the debugger. It is (as far
4480 as we know) the only published document on this fascinating topic. We
4481 encourage you to read it, compare it to the stabs information on your
4482 system, and send improvements on the document in general (to
4483 bug-gdb@prep.ai.mit.edu).
4485 And, of course, many bugs have been fixed.
4488 *** Changes in GDB-4.6:
4490 * Better support for C++ function names
4492 GDB now accepts as input the "demangled form" of C++ overloaded function
4493 names and member function names, and can do command completion on such names
4494 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4495 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4496 Make use of command completion, it is your friend.
4498 GDB also now accepts a variety of C++ mangled symbol formats. They are
4499 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4500 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4501 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4502 for the list of formats.
4504 * G++ symbol mangling problem
4506 Recent versions of gcc have a bug in how they emit debugging information for
4507 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4508 directory) can be applied to gcc to fix the problem. Alternatively, if you
4509 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4510 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4511 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4514 * New 'maintenance' command
4516 All of the commands related to hacking GDB internals have been moved out of
4517 the main command set, and now live behind the 'maintenance' command. This
4518 can also be abbreviated as 'mt'. The following changes were made:
4520 dump-me -> maintenance dump-me
4521 info all-breakpoints -> maintenance info breakpoints
4522 printmsyms -> maintenance print msyms
4523 printobjfiles -> maintenance print objfiles
4524 printpsyms -> maintenance print psymbols
4525 printsyms -> maintenance print symbols
4527 The following commands are new:
4529 maintenance demangle Call internal GDB demangler routine to
4530 demangle a C++ link name and prints the result.
4531 maintenance print type Print a type chain for a given symbol
4533 * Change to .gdbinit file processing
4535 We now read the $HOME/.gdbinit file before processing the argv arguments
4536 (e.g. reading symbol files or core files). This allows global parameters to
4537 be set, which will apply during the symbol reading. The ./.gdbinit is still
4538 read after argv processing.
4540 * New hosts supported
4542 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4544 GNU/Linux support i386-unknown-linux or linux
4546 We are also including code to support the HP/PA running BSD and HPUX. This
4547 is almost guaranteed not to work, as we didn't have time to test or build it
4548 for this release. We are including it so that the more adventurous (or
4549 masochistic) of you can play with it. We also had major problems with the
4550 fact that the compiler that we got from HP doesn't support the -g option.
4553 * New targets supported
4555 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4557 * More smarts about finding #include files
4559 GDB now remembers the compilation directory for all include files, and for
4560 all files from which C is generated (like yacc and lex sources). This
4561 greatly improves GDB's ability to find yacc/lex sources, and include files,
4562 especially if you are debugging your program from a directory different from
4563 the one that contains your sources.
4565 We also fixed a bug which caused difficulty with listing and setting
4566 breakpoints in include files which contain C code. (In the past, you had to
4567 try twice in order to list an include file that you hadn't looked at before.)
4569 * Interesting infernals change
4571 GDB now deals with arbitrary numbers of sections, where the symbols for each
4572 section must be relocated relative to that section's landing place in the
4573 target's address space. This work was needed to support ELF with embedded
4574 stabs used by Solaris-2.0.
4576 * Bug fixes (of course!)
4578 There have been loads of fixes for the following things:
4579 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4580 i960, stabs, DOS(GO32), procfs, etc...
4582 See the ChangeLog for details.
4584 *** Changes in GDB-4.5:
4586 * New machines supported (host and target)
4588 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4590 SGI Irix-4.x mips-sgi-irix4 or iris4
4592 * New malloc package
4594 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4595 Mmalloc is capable of handling mutiple heaps of memory. It is also
4596 capable of saving a heap to a file, and then mapping it back in later.
4597 This can be used to greatly speedup the startup of GDB by using a
4598 pre-parsed symbol table which lives in a mmalloc managed heap. For
4599 more details, please read mmalloc/mmalloc.texi.
4603 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4604 'help info proc' for details.
4606 * MIPS ecoff symbol table format
4608 The code that reads MIPS symbol table format is now supported on all hosts.
4609 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4612 * File name changes for MS-DOS
4614 Many files in the config directories have been renamed to make it easier to
4615 support GDB on MS-DOSe systems (which have very restrictive file name
4616 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4617 environment) is close to working but has some remaining problems. Note
4618 that debugging of DOS programs is not supported, due to limitations
4619 in the ``operating system'', but it can be used to host cross-debugging.
4621 * Cross byte order fixes
4623 Many fixes have been made to support cross debugging of Sparc and MIPS
4624 targets from hosts whose byte order differs.
4626 * New -mapped and -readnow options
4628 If memory-mapped files are available on your system through the 'mmap'
4629 system call, you can use the -mapped option on the `file' or
4630 `symbol-file' commands to cause GDB to write the symbols from your
4631 program into a reusable file. If the program you are debugging is
4632 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4633 Future GDB debugging sessions will notice the presence of this file,
4634 and will quickly map in symbol information from it, rather than reading
4635 the symbol table from the executable program. Using the '-mapped'
4636 option in a GDB `file' or `symbol-file' command has the same effect as
4637 starting GDB with the '-mapped' command-line option.
4639 You can cause GDB to read the entire symbol table immediately by using
4640 the '-readnow' option with any of the commands that load symbol table
4641 information (or on the GDB command line). This makes the command
4642 slower, but makes future operations faster.
4644 The -mapped and -readnow options are typically combined in order to
4645 build a `fred.syms' file that contains complete symbol information.
4646 A simple GDB invocation to do nothing but build a `.syms' file for future
4649 gdb -batch -nx -mapped -readnow programname
4651 The `.syms' file is specific to the host machine on which GDB is run.
4652 It holds an exact image of GDB's internal symbol table. It cannot be
4653 shared across multiple host platforms.
4655 * longjmp() handling
4657 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4658 siglongjmp() without losing control. This feature has not yet been ported to
4659 all systems. It currently works on many 386 platforms, all MIPS-based
4660 platforms (SGI, DECstation, etc), and Sun3/4.
4664 Preliminary work has been put in to support the new Solaris OS from Sun. At
4665 this time, it can control and debug processes, but it is not capable of
4670 As always, many many bug fixes. The major areas were with g++, and mipsread.
4671 People using the MIPS-based platforms should experience fewer mysterious
4672 crashes and trashed symbol tables.
4674 *** Changes in GDB-4.4:
4676 * New machines supported (host and target)
4678 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4680 BSD Reno on Vax vax-dec-bsd
4681 Ultrix on Vax vax-dec-ultrix
4683 * New machines supported (target)
4685 AMD 29000 embedded, using EBMON a29k-none-none
4689 GDB continues to improve its handling of C++. `References' work better.
4690 The demangler has also been improved, and now deals with symbols mangled as
4691 per the Annotated C++ Reference Guide.
4693 GDB also now handles `stabs' symbol information embedded in MIPS
4694 `ecoff' symbol tables. Since the ecoff format was not easily
4695 extensible to handle new languages such as C++, this appeared to be a
4696 good way to put C++ debugging info into MIPS binaries. This option
4697 will be supported in the GNU C compiler, version 2, when it is
4700 * New features for SVR4
4702 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4703 shared libraries. Debugging dynamically linked programs should present
4704 only minor differences from debugging statically linked programs.
4706 The `info proc' command will print out information about any process
4707 on an SVR4 system (including the one you are debugging). At the moment,
4708 it prints the address mappings of the process.
4710 If you bring up GDB on another SVR4 system, please send mail to
4711 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4713 * Better dynamic linking support in SunOS
4715 Reading symbols from shared libraries which contain debugging symbols
4716 now works properly. However, there remain issues such as automatic
4717 skipping of `transfer vector' code during function calls, which
4718 make it harder to debug code in a shared library, than to debug the
4719 same code linked statically.
4723 GDB is now using the latest `getopt' routines from the FSF. This
4724 version accepts the -- prefix for options with long names. GDB will
4725 continue to accept the old forms (-option and +option) as well.
4726 Various single letter abbreviations for options have been explicity
4727 added to the option table so that they won't get overshadowed in the
4728 future by other options that begin with the same letter.
4732 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4733 Many assorted bugs have been handled. Many more remain to be handled.
4734 See the various ChangeLog files (primarily in gdb and bfd) for details.
4737 *** Changes in GDB-4.3:
4739 * New machines supported (host and target)
4741 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4742 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4743 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4745 * Almost SCO Unix support
4747 We had hoped to support:
4748 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4749 (except for core file support), but we discovered very late in the release
4750 that it has problems with process groups that render gdb unusable. Sorry
4751 about that. I encourage people to fix it and post the fixes.
4753 * Preliminary ELF and DWARF support
4755 GDB can read ELF object files on System V Release 4, and can handle
4756 debugging records for C, in DWARF format, in ELF files. This support
4757 is preliminary. If you bring up GDB on another SVR4 system, please
4758 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4763 GDB now uses the latest `readline' library. One user-visible change
4764 is that two tabs will list possible command completions, which previously
4765 required typing M-? (meta-question mark, or ESC ?).
4769 The `stepi' bug that many of you noticed has been squashed.
4770 Many bugs in C++ have been handled. Many more remain to be handled.
4771 See the various ChangeLog files (primarily in gdb and bfd) for details.
4773 * State of the MIPS world (in case you wondered):
4775 GDB can understand the symbol tables emitted by the compilers
4776 supplied by most vendors of MIPS-based machines, including DEC. These
4777 symbol tables are in a format that essentially nobody else uses.
4779 Some versions of gcc come with an assembler post-processor called
4780 mips-tfile. This program is required if you want to do source-level
4781 debugging of gcc-compiled programs. I believe FSF does not ship
4782 mips-tfile with gcc version 1, but it will eventually come with gcc
4785 Debugging of g++ output remains a problem. g++ version 1.xx does not
4786 really support it at all. (If you're lucky, you should be able to get
4787 line numbers and stack traces to work, but no parameters or local
4788 variables.) With some work it should be possible to improve the
4791 When gcc version 2 is released, you will have somewhat better luck.
4792 However, even then you will get confusing results for inheritance and
4795 We will eventually provide full debugging of g++ output on
4796 DECstations. This will probably involve some kind of stabs-in-ecoff
4797 encapulation, but the details have not been worked out yet.
4800 *** Changes in GDB-4.2:
4802 * Improved configuration
4804 Only one copy of `configure' exists now, and it is not self-modifying.
4805 Porting BFD is simpler.
4809 The `step' and `next' commands now only stop at the first instruction
4810 of a source line. This prevents the multiple stops that used to occur
4811 in switch statements, for-loops, etc. `Step' continues to stop if a
4812 function that has debugging information is called within the line.
4816 Lots of small bugs fixed. More remain.
4818 * New host supported (not target)
4820 Intel 386 PC clone running Mach i386-none-mach
4823 *** Changes in GDB-4.1:
4825 * Multiple source language support
4827 GDB now has internal scaffolding to handle several source languages.
4828 It determines the type of each source file from its filename extension,
4829 and will switch expression parsing and number formatting to match the
4830 language of the function in the currently selected stack frame.
4831 You can also specifically set the language to be used, with
4832 `set language c' or `set language modula-2'.
4836 GDB now has preliminary support for the GNU Modula-2 compiler,
4837 currently under development at the State University of New York at
4838 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4839 continue through the fall of 1991 and into 1992.
4841 Other Modula-2 compilers are currently not supported, and attempting to
4842 debug programs compiled with them will likely result in an error as the
4843 symbol table is read. Feel free to work on it, though!
4845 There are hooks in GDB for strict type checking and range checking,
4846 in the `Modula-2 philosophy', but they do not currently work.
4850 GDB can now write to executable and core files (e.g. patch
4851 a variable's value). You must turn this switch on, specify
4852 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4853 by assigning a new value to a variable. Modifications take
4856 * Automatic SunOS shared library reading
4858 When you run your program, GDB automatically determines where its
4859 shared libraries (if any) have been loaded, and reads their symbols.
4860 The `share' command is no longer needed. This also works when
4861 examining core files.
4865 You can specify the number of lines that the `list' command shows.
4868 * New machines supported (host and target)
4870 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4871 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4872 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4874 * New hosts supported (not targets)
4876 IBM RT/PC: romp-ibm-aix or rtpc
4878 * New targets supported (not hosts)
4880 AMD 29000 embedded with COFF a29k-none-coff
4881 AMD 29000 embedded with a.out a29k-none-aout
4882 Ultracomputer remote kernel debug a29k-nyu-kern
4884 * New remote interfaces
4890 *** Changes in GDB-4.0:
4894 Wide output is wrapped at good places to make the output more readable.
4896 Gdb now supports cross-debugging from a host machine of one type to a
4897 target machine of another type. Communication with the target system
4898 is over serial lines. The ``target'' command handles connecting to the
4899 remote system; the ``load'' command will download a program into the
4900 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4901 also supports debugging of realtime processes running under VxWorks,
4902 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4903 stub on the target system.
4905 New CPUs supported include the AMD 29000 and Intel 960.
4907 GDB now reads object files and symbol tables via a ``binary file''
4908 library, which allows a single copy of GDB to debug programs of multiple
4909 object file types such as a.out and coff.
4911 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4912 refcard.dvi and refcard.ps are available to format it).
4915 * Control-Variable user interface simplified
4917 All variables that control the operation of the debugger can be set
4918 by the ``set'' command, and displayed by the ``show'' command.
4920 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4921 ``Show prompt'' produces the response:
4922 Gdb's prompt is new-gdb=>.
4924 What follows are the NEW set commands. The command ``help set'' will
4925 print a complete list of old and new set commands. ``help set FOO''
4926 will give a longer description of the variable FOO. ``show'' will show
4927 all of the variable descriptions and their current settings.
4929 confirm on/off: Enables warning questions for operations that are
4930 hard to recover from, e.g. rerunning the program while
4931 it is already running. Default is ON.
4933 editing on/off: Enables EMACS style command line editing
4934 of input. Previous lines can be recalled with
4935 control-P, the current line can be edited with control-B,
4936 you can search for commands with control-R, etc.
4939 history filename NAME: NAME is where the gdb command history
4940 will be stored. The default is .gdb_history,
4941 or the value of the environment variable
4944 history size N: The size, in commands, of the command history. The
4945 default is 256, or the value of the environment variable
4948 history save on/off: If this value is set to ON, the history file will
4949 be saved after exiting gdb. If set to OFF, the
4950 file will not be saved. The default is OFF.
4952 history expansion on/off: If this value is set to ON, then csh-like
4953 history expansion will be performed on
4954 command line input. The default is OFF.
4956 radix N: Sets the default radix for input and output. It can be set
4957 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4958 in the current radix, so "set radix 10" is always a no-op.
4960 height N: This integer value is the number of lines on a page. Default
4961 is 24, the current `stty rows'' setting, or the ``li#''
4962 setting from the termcap entry matching the environment
4965 width N: This integer value is the number of characters on a line.
4966 Default is 80, the current `stty cols'' setting, or the ``co#''
4967 setting from the termcap entry matching the environment
4970 Note: ``set screensize'' is obsolete. Use ``set height'' and
4971 ``set width'' instead.
4973 print address on/off: Print memory addresses in various command displays,
4974 such as stack traces and structure values. Gdb looks
4975 more ``symbolic'' if you turn this off; it looks more
4976 ``machine level'' with it on. Default is ON.
4978 print array on/off: Prettyprint arrays. New convenient format! Default
4981 print demangle on/off: Print C++ symbols in "source" form if on,
4984 print asm-demangle on/off: Same, for assembler level printouts
4987 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4990 * Support for Epoch Environment.
4992 The epoch environment is a version of Emacs v18 with windowing. One
4993 new command, ``inspect'', is identical to ``print'', except that if you
4994 are running in the epoch environment, the value is printed in its own
4998 * Support for Shared Libraries
5000 GDB can now debug programs and core files that use SunOS shared libraries.
5001 Symbols from a shared library cannot be referenced
5002 before the shared library has been linked with the program (this
5003 happens after you type ``run'' and before the function main() is entered).
5004 At any time after this linking (including when examining core files
5005 from dynamically linked programs), gdb reads the symbols from each
5006 shared library when you type the ``sharedlibrary'' command.
5007 It can be abbreviated ``share''.
5009 sharedlibrary REGEXP: Load shared object library symbols for files
5010 matching a unix regular expression. No argument
5011 indicates to load symbols for all shared libraries.
5013 info sharedlibrary: Status of loaded shared libraries.
5018 A watchpoint stops execution of a program whenever the value of an
5019 expression changes. Checking for this slows down execution
5020 tremendously whenever you are in the scope of the expression, but is
5021 quite useful for catching tough ``bit-spreader'' or pointer misuse
5022 problems. Some machines such as the 386 have hardware for doing this
5023 more quickly, and future versions of gdb will use this hardware.
5025 watch EXP: Set a watchpoint (breakpoint) for an expression.
5027 info watchpoints: Information about your watchpoints.
5029 delete N: Deletes watchpoint number N (same as breakpoints).
5030 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5031 enable N: Re-enables watchpoint number N (same as breakpoints).
5034 * C++ multiple inheritance
5036 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5039 * C++ exception handling
5041 Gdb now supports limited C++ exception handling. Besides the existing
5042 ability to breakpoint on an exception handler, gdb can breakpoint on
5043 the raising of an exception (before the stack is peeled back to the
5046 catch FOO: If there is a FOO exception handler in the dynamic scope,
5047 set a breakpoint to catch exceptions which may be raised there.
5048 Multiple exceptions (``catch foo bar baz'') may be caught.
5050 info catch: Lists all exceptions which may be caught in the
5051 current stack frame.
5054 * Minor command changes
5056 The command ``call func (arg, arg, ...)'' now acts like the print
5057 command, except it does not print or save a value if the function's result
5058 is void. This is similar to dbx usage.
5060 The ``up'' and ``down'' commands now always print the frame they end up
5061 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5062 frames without printing.
5064 * New directory command
5066 'dir' now adds directories to the FRONT of the source search path.
5067 The path starts off empty. Source files that contain debug information
5068 about the directory in which they were compiled can be found even
5069 with an empty path; Sun CC and GCC include this information. If GDB can't
5070 find your source file in the current directory, type "dir .".
5072 * Configuring GDB for compilation
5074 For normal use, type ``./configure host''. See README or gdb.texinfo
5077 GDB now handles cross debugging. If you are remotely debugging between
5078 two different machines, type ``./configure host -target=targ''.
5079 Host is the machine where GDB will run; targ is the machine
5080 where the program that you are debugging will run.