1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.4
6 * GDB now supports access to MIPS DSP registers on Linux targets.
8 * GDB now supports debugging microMIPS binaries.
10 * The "info os" command on GNU/Linux can now display information on
11 several new classes of objects managed by the operating system:
12 "info os procgroups" lists process groups
13 "info os files" lists file descriptors
14 "info os sockets" lists internet-domain sockets
15 "info os shm" lists shared-memory regions
16 "info os semaphores" lists semaphores
17 "info os msg" lists message queues
18 "info os modules" lists loaded kernel modules
20 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
21 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
22 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
23 options and inspect the probe arguments using the new $_probe_arg family
24 of convenience variables. You can obtain more information about SystemTap
25 in <http://sourceware.org/systemtap/>.
27 * GDB now supports reversible debugging on ARM, it allows you to
28 debug basic ARM and THUMB instructions, and provides
29 record/replay support.
31 * The option "symbol-reloading" has been deleted as it is no longer used.
35 ** GDB commands implemented in Python can now be put in command class
38 ** The "maint set python print-stack on|off" is now deleted.
40 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
41 apply "flag enum"-style pretty-printing to any enum.
43 ** gdb.lookup_symbol can now work when there is no current frame.
45 ** gdb.Symbol now has a 'line' attribute, holding the line number in
46 the source at which the symbol was defined.
48 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
49 method 'value'. The former indicates whether the symbol needs a
50 frame in order to compute its value, and the latter computes the
53 ** A new method 'referenced_value' on gdb.Value objects which can
54 dereference pointer as well as C++ reference values.
56 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
57 which return the global and static blocks (as gdb.Block objects),
58 of the underlying symbol table, respectively.
60 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
61 object associated with a PC value.
63 * Go language support.
64 GDB now supports debugging programs written in the Go programming
67 * GDBserver now supports stdio connections.
68 E.g. (gdb) target remote | ssh myhost gdbserver - hello
70 * The binary "gdbtui" can no longer be built or installed.
71 Use "gdb -tui" instead.
73 * GDB will now print "flag" enums specially. A flag enum is one where
74 all the enumerator values have no bits in common when pairwise
75 "and"ed. When printing a value whose type is a flag enum, GDB will
76 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
77 (gdb) print (enum E) 3
80 * The filename part of a linespec will now match trailing components
81 of a source file name. For example, "break gcc/expr.c:1000" will
82 now set a breakpoint in build/gcc/expr.c, but not
85 * The "info proc" and "generate-core-file" commands will now also
86 work on remote targets connected to GDBserver on Linux.
88 * The command "info catch" has been removed. It has been disabled
91 * The "catch exception" and "catch assert" commands now accept
92 a condition at the end of the command, much like the "break"
93 command does. For instance:
95 (gdb) catch exception Constraint_Error if Barrier = True
97 Previously, it was possible to add a condition to such catchpoints,
98 but it had to be done as a second step, after the catchpoint had been
99 created, using the "condition" command.
101 * The "info static-tracepoint-marker" command will now also work on
102 native Linux targets with in-process agent.
104 * GDB can now set breakpoints on inlined functions.
106 * The .gdb_index section has been updated to include symbols for
107 inlined functions. GDB will ignore older .gdb_index sections by
108 default, which could cause symbol files to be loaded more slowly
109 until their .gdb_index sections can be recreated. The new option
110 --use-deprecated-index-sections will cause GDB to use any older
111 .gdb_index sections it finds. This will restore performance, but
112 the ability to set breakpoints on inlined functions will be lost
113 in symbol files with older .gdb_index sections.
115 * Ada support for GDB/MI Variable Objects has been added.
117 * GDB can now support 'breakpoint always-inserted mode' in 'record'
122 ** New command -info-os is the MI equivalent of "info os".
126 ** "catch load" and "catch unload" can be used to stop when a shared
127 library is loaded or unloaded, respectively.
129 ** "enable count" can be used to auto-disable a breakpoint after
132 ** "info vtbl" can be used to show the virtual method tables for
133 C++ and Java objects.
135 ** "explore" and its sub commands "explore value" and "explore type"
136 can be used to reccursively explore values and types of
137 expressions. These commands are available only if GDB is
138 configured with '--with-python'.
140 ** "info auto-load" shows status of all kinds of auto-loaded files,
141 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
142 sequences of commands files, "info auto-load python-scripts"
143 shows status of auto-loading Python script files,
144 "info auto-load local-gdbinit" shows status of loading init file
145 (.gdbinit) from current directory and "info auto-load libthread-db" shows
146 status of inferior specific thread debugging shared library loading.
148 ** "info auto-load-scripts", "set auto-load-scripts on|off"
149 and "show auto-load-scripts" commands have been deprecated, use their
150 "info auto-load python-scripts", "set auto-load python-scripts on|off"
151 and "show auto-load python-scripts" counterparts instead.
153 ** "dprintf location,format,args..." creates a dynamic printf, which
154 is basically a breakpoint that does a printf and immediately
155 resumes your program's execution, so it is like a printf that you
156 can insert dynamically at runtime instead of at compiletime.
158 ** "set print symbol"
160 Controls whether GDB attempts to display the symbol, if any,
161 corresponding to addresses it prints. This defaults to "on", but
162 you can set it to "off" to restore GDB's previous behavior.
166 Renesas RL78 rl78-*-elf
167 HP OpenVMS ia64 ia64-hp-openvms*
169 * GDBserver supports evaluation of breakpoint conditions. When
170 support is advertised by GDBserver, GDB may be told to send the
171 breakpoint conditions in bytecode form to GDBserver. GDBserver
172 will only report the breakpoint trigger to GDB when its condition
178 show mips compression
179 Select the compressed ISA encoding used in functions that have no symbol
180 information available. The encoding can be set to either of:
183 and is updated automatically from ELF file flags if available.
185 set breakpoint condition-evaluation
186 show breakpoint condition-evaluation
187 Control whether breakpoint conditions are evaluated by GDB ("host") or by
188 GDBserver ("target"). Default option "auto" chooses the most efficient
190 This option can improve debugger efficiency depending on the speed of the
194 Disable auto-loading globally.
197 Show auto-loading setting of all kinds of auto-loaded files.
199 set auto-load gdb-scripts on|off
200 show auto-load gdb-scripts
201 Control auto-loading of GDB canned sequences of commands files.
203 set auto-load python-scripts on|off
204 show auto-load python-scripts
205 Control auto-loading of Python script files.
207 set auto-load local-gdbinit on|off
208 show auto-load local-gdbinit
209 Control loading of init file (.gdbinit) from current directory.
211 set auto-load libthread-db on|off
212 show auto-load libthread-db
213 Control auto-loading of inferior specific thread debugging shared library.
215 set auto-load scripts-directory <dir1>[:<dir2>...]
216 show auto-load scripts-directory
217 Set a list of directories from which to load auto-loaded scripts.
218 Automatically loaded Python scripts and GDB scripts are located in one
219 of the directories listed by this option.
220 The delimiter (':' above) may differ according to the host platform.
222 set auto-load safe-path <dir1>[:<dir2>...]
223 show auto-load safe-path
224 Set a list of directories from which it is safe to auto-load files.
225 The delimiter (':' above) may differ according to the host platform.
227 set debug auto-load on|off
229 Control display of debugging info for auto-loading the files above.
231 set dprintf-style gdb|call
233 Control the way in which a dynamic printf is performed; "gdb" requests
234 a GDB printf command, while "call" causes dprintf to call a function
237 set dprintf-function <expr>
238 show dprintf-function
239 set dprintf-channel <expr>
241 Set the function and optional first argument to the call when using
242 the "call" style of dynamic printf.
244 * New configure options
247 Configure default value for the 'set auto-load scripts-directory'
248 setting above. It defaults to '$debugdir:$datadir/auto-load',
249 $debugdir representing global debugging info directories (available
250 via 'show debug-file-directory') and $datadir representing GDB's data
251 directory (available via 'show data-directory').
253 --with-auto-load-safe-path
254 Configure default value for the 'set auto-load safe-path' setting
255 above. It defaults to the --with-auto-load-dir setting.
257 --without-auto-load-safe-path
258 Set 'set auto-load safe-path' to '/', effectively disabling this
263 z0/z1 conditional breakpoints extension
265 The z0/z1 breakpoint insertion packets have been extended to carry
266 a list of conditional expressions over to the remote stub depending on the
267 condition evaluation mode. The use of this extension can be controlled
268 via the "set remote conditional-breakpoints-packet" command.
272 Specify the signals which the remote stub may pass to the debugged
273 program without GDB involvement.
275 * New command line options
277 --init-command=FILE, -ix Like --command, -x but execute it
278 before loading inferior.
279 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
280 execute it before loading inferior.
282 *** Changes in GDB 7.4
284 * GDB now handles ambiguous linespecs more consistently; the existing
285 FILE:LINE support has been expanded to other types of linespecs. A
286 breakpoint will now be set on all matching locations in all
287 inferiors, and locations will be added or removed according to
290 * GDB now allows you to skip uninteresting functions and files when
291 stepping with the "skip function" and "skip file" commands.
293 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
294 and "show remote hardware-watchpoint-length-limit". These allows to
295 set or show the maximum length limit (in bytes) of a remote
296 target hardware watchpoint.
298 This allows e.g. to use "unlimited" hardware watchpoints with the
299 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
300 watchpoints are slower than real hardware watchpoints but are
301 significantly faster than gdb software watchpoints.
305 ** The register_pretty_printer function in module gdb.printing now takes
306 an optional `replace' argument. If True, the new printer replaces any
309 ** The "maint set python print-stack on|off" command has been
310 deprecated and will be deleted in GDB 7.5.
311 A new command: "set python print-stack none|full|message" has
312 replaced it. Additionally, the default for "print-stack" is
313 now "message", which just prints the error message without
316 ** A prompt substitution hook (prompt_hook) is now available to the
319 ** A new Python module, gdb.prompt has been added to the GDB Python
320 modules library. This module provides functionality for
321 escape sequences in prompts (used by set/show
322 extended-prompt). These escape sequences are replaced by their
325 ** Python commands and convenience-functions located in
326 'data-directory'/python/gdb/command and
327 'data-directory'/python/gdb/function are now automatically loaded
330 ** Blocks now provide four new attributes. global_block and
331 static_block will return the global and static blocks
332 respectively. is_static and is_global are boolean attributes
333 that indicate if the block is one of those two types.
335 ** Symbols now provide the "type" attribute, the type of the symbol.
337 ** The "gdb.breakpoint" function has been deprecated in favor of
340 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
341 of a function. This class is based on the "finish" command
342 available in the CLI.
344 ** Type objects for struct and union types now allow access to
345 the fields using standard Python dictionary (mapping) methods.
346 For example, "some_type['myfield']" now works, as does
349 ** A new event "gdb.new_objfile" has been added, triggered by loading a
352 ** A new function, "deep_items" has been added to the gdb.types
353 module in the GDB Python modules library. This function returns
354 an iterator over the fields of a struct or union type. Unlike
355 the standard Python "iteritems" method, it will recursively traverse
356 any anonymous fields.
360 ** "*stopped" events can report several new "reason"s, such as
363 ** Breakpoint changes are now notified using new async records, like
364 "=breakpoint-modified".
366 ** New command -ada-task-info.
368 * libthread-db-search-path now supports two special values: $sdir and $pdir.
369 $sdir specifies the default system locations of shared libraries.
370 $pdir specifies the directory where the libpthread used by the application
373 GDB no longer looks in $sdir and $pdir after it has searched the directories
374 mentioned in libthread-db-search-path. If you want to search those
375 directories, they must be specified in libthread-db-search-path.
376 The default value of libthread-db-search-path on GNU/Linux and Solaris
377 systems is now "$sdir:$pdir".
379 $pdir is not supported by gdbserver, it is currently ignored.
380 $sdir is supported by gdbserver.
382 * New configure option --with-iconv-bin.
383 When using the internationalization support like the one in the GNU C
384 library, GDB will invoke the "iconv" program to get a list of supported
385 character sets. If this program lives in a non-standard location, one can
386 use this option to specify where to find it.
388 * When natively debugging programs on PowerPC BookE processors running
389 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
390 watchpoints, which specify a mask in addition to an address to watch.
391 The mask specifies that some bits of an address (the bits which are
392 reset in the mask) should be ignored when matching the address accessed
393 by the inferior against the watchpoint address. See the "PowerPC Embedded"
394 section in the user manual for more details.
396 * The new option --once causes GDBserver to stop listening for connections once
397 the first connection is made. The listening port used by GDBserver will
398 become available after that.
400 * New commands "info macros" and "alias" have been added.
402 * New function parameters suffix @entry specifies value of function parameter
403 at the time the function got called. Entry values are available only since
409 "!" is now an alias of the "shell" command.
410 Note that no space is needed between "!" and SHELL COMMAND.
414 watch EXPRESSION mask MASK_VALUE
415 The watch command now supports the mask argument which allows creation
416 of masked watchpoints, if the current architecture supports this feature.
418 info auto-load-scripts [REGEXP]
419 This command was formerly named "maintenance print section-scripts".
420 It is now generally useful and is no longer a maintenance-only command.
422 info macro [-all] [--] MACRO
423 The info macro command has new options `-all' and `--'. The first for
424 printing all definitions of a macro. The second for explicitly specifying
425 the end of arguments and the beginning of the macro name in case the macro
426 name starts with a hyphen.
428 collect[/s] EXPRESSIONS
429 The tracepoint collect command now takes an optional modifier "/s"
430 that directs it to dereference pointer-to-character types and
431 collect the bytes of memory up to a zero byte. The behavior is
432 similar to what you see when you use the regular print command on a
433 string. An optional integer following the "/s" sets a bound on the
434 number of bytes that will be collected.
437 The trace start command now interprets any supplied arguments as a
438 note to be recorded with the trace run, with an effect similar to
439 setting the variable trace-notes.
442 The trace stop command now interprets any arguments as a note to be
443 mentioned along with the tstatus report that the trace was stopped
444 with a command. The effect is similar to setting the variable
447 * Tracepoints can now be enabled and disabled at any time after a trace
448 experiment has been started using the standard "enable" and "disable"
449 commands. It is now possible to start a trace experiment with no enabled
450 tracepoints; GDB will display a warning, but will allow the experiment to
451 begin, assuming that tracepoints will be enabled as needed while the trace
454 * Fast tracepoints on 32-bit x86-architectures can now be placed at
455 locations with 4-byte instructions, when they were previously
456 limited to locations with instructions of 5 bytes or longer.
462 Set the GDB prompt, and allow escape sequences to be inserted to
463 display miscellaneous information (see 'help set extended-prompt'
464 for the list of sequences). This prompt (and any information
465 accessed through the escape sequences) is updated every time the
468 set print entry-values (both|compact|default|if-needed|no|only|preferred)
469 show print entry-values
470 Set printing of frame argument values at function entry. In some cases
471 GDB can determine the value of function argument which was passed by the
472 function caller, even if the value was modified inside the called function.
474 set debug entry-values
475 show debug entry-values
476 Control display of debugging info for determining frame argument values at
477 function entry and virtual tail call frames.
479 set basenames-may-differ
480 show basenames-may-differ
481 Set whether a source file may have multiple base names.
482 (A "base name" is the name of a file with the directory part removed.
483 Example: The base name of "/home/user/hello.c" is "hello.c".)
484 If set, GDB will canonicalize file names (e.g., expand symlinks)
485 before comparing them. Canonicalization is an expensive operation,
486 but it allows the same file be known by more than one base name.
487 If not set (the default), all source files are assumed to have just
488 one base name, and gdb will do file name comparisons more efficiently.
494 Set a user name and notes for the current and any future trace runs.
495 This is useful for long-running and/or disconnected traces, to
496 inform others (or yourself) as to who is running the trace, supply
497 contact information, or otherwise explain what is going on.
500 show trace-stop-notes
501 Set a note attached to the trace run, that is displayed when the
502 trace has been stopped by a tstop command. This is useful for
503 instance as an explanation, if you are stopping a trace run that was
504 started by someone else.
510 Dynamically enable a tracepoint in a started trace experiment.
514 Dynamically disable a tracepoint in a started trace experiment.
518 Set the user and notes of the trace run.
522 Query the current status of a tracepoint.
526 Query the minimum length of instruction at which a fast tracepoint may
529 * Dcache size (number of lines) and line-size are now runtime-configurable
530 via "set dcache line" and "set dcache line-size" commands.
534 Texas Instruments TMS320C6x tic6x-*-*
538 Renesas RL78 rl78-*-elf
540 *** Changes in GDB 7.3.1
542 * The build failure for NetBSD and OpenBSD targets have now been fixed.
544 *** Changes in GDB 7.3
546 * GDB has a new command: "thread find [REGEXP]".
547 It finds the thread id whose name, target id, or thread extra info
548 matches the given regular expression.
550 * The "catch syscall" command now works on mips*-linux* targets.
552 * The -data-disassemble MI command now supports modes 2 and 3 for
553 dumping the instruction opcodes.
555 * New command line options
557 -data-directory DIR Specify DIR as the "data-directory".
558 This is mostly for testing purposes.
560 * The "maint set python auto-load on|off" command has been renamed to
561 "set auto-load-scripts on|off".
563 * GDB has a new command: "set directories".
564 It is like the "dir" command except that it replaces the
565 source path list instead of augmenting it.
567 * GDB now understands thread names.
569 On GNU/Linux, "info threads" will display the thread name as set by
570 prctl or pthread_setname_np.
572 There is also a new command, "thread name", which can be used to
573 assign a name internally for GDB to display.
576 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
577 has been integrated into GDB.
581 ** The function gdb.Write now accepts an optional keyword 'stream'.
582 This keyword, when provided, will direct the output to either
583 stdout, stderr, or GDB's logging output.
585 ** Parameters can now be be sub-classed in Python, and in particular
586 you may implement the get_set_doc and get_show_doc functions.
587 This improves how Parameter set/show documentation is processed
588 and allows for more dynamic content.
590 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
591 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
592 have an is_valid method.
594 ** Breakpoints can now be sub-classed in Python, and in particular
595 you may implement a 'stop' function that is executed each time
596 the inferior reaches that breakpoint.
598 ** New function gdb.lookup_global_symbol looks up a global symbol.
600 ** GDB values in Python are now callable if the value represents a
601 function. For example, if 'some_value' represents a function that
602 takes two integer parameters and returns a value, you can call
603 that function like so:
605 result = some_value (10,20)
607 ** Module gdb.types has been added.
608 It contains a collection of utilities for working with gdb.Types objects:
609 get_basic_type, has_field, make_enum_dict.
611 ** Module gdb.printing has been added.
612 It contains utilities for writing and registering pretty-printers.
613 New classes: PrettyPrinter, SubPrettyPrinter,
614 RegexpCollectionPrettyPrinter.
615 New function: register_pretty_printer.
617 ** New commands "info pretty-printers", "enable pretty-printer" and
618 "disable pretty-printer" have been added.
620 ** gdb.parameter("directories") is now available.
622 ** New function gdb.newest_frame returns the newest frame in the
625 ** The gdb.InferiorThread class has a new "name" attribute. This
626 holds the thread's name.
628 ** Python Support for Inferior events.
629 Python scripts can add observers to be notified of events
630 occurring in the process being debugged.
631 The following events are currently supported:
632 - gdb.events.cont Continue event.
633 - gdb.events.exited Inferior exited event.
634 - gdb.events.stop Signal received, and Breakpoint hit events.
638 ** GDB now puts template parameters in scope when debugging in an
639 instantiation. For example, if you have:
641 template<int X> int func (void) { return X; }
643 then if you step into func<5>, "print X" will show "5". This
644 feature requires proper debuginfo support from the compiler; it
645 was added to GCC 4.5.
647 ** The motion commands "next", "finish", "until", and "advance" now
648 work better when exceptions are thrown. In particular, GDB will
649 no longer lose control of the inferior; instead, the GDB will
650 stop the inferior at the point at which the exception is caught.
651 This functionality requires a change in the exception handling
652 code that was introduced in GCC 4.5.
654 * GDB now follows GCC's rules on accessing volatile objects when
655 reading or writing target state during expression evaluation.
656 One notable difference to prior behavior is that "print x = 0"
657 no longer generates a read of x; the value of the assignment is
658 now always taken directly from the value being assigned.
660 * GDB now has some support for using labels in the program's source in
661 linespecs. For instance, you can use "advance label" to continue
662 execution to a label.
664 * GDB now has support for reading and writing a new .gdb_index
665 section. This section holds a fast index of DWARF debugging
666 information and can be used to greatly speed up GDB startup and
667 operation. See the documentation for `save gdb-index' for details.
669 * The "watch" command now accepts an optional "-location" argument.
670 When used, this causes GDB to watch the memory referred to by the
671 expression. Such a watchpoint is never deleted due to it going out
674 * GDB now supports thread debugging of core dumps on GNU/Linux.
676 GDB now activates thread debugging using the libthread_db library
677 when debugging GNU/Linux core dumps, similarly to when debugging
678 live processes. As a result, when debugging a core dump file, GDB
679 is now able to display pthread_t ids of threads. For example, "info
680 threads" shows the same output as when debugging the process when it
681 was live. In earlier releases, you'd see something like this:
684 * 1 LWP 6780 main () at main.c:10
686 While now you see this:
689 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
691 It is also now possible to inspect TLS variables when debugging core
694 When debugging a core dump generated on a machine other than the one
695 used to run GDB, you may need to point GDB at the correct
696 libthread_db library with the "set libthread-db-search-path"
697 command. See the user manual for more details on this command.
699 * When natively debugging programs on PowerPC BookE processors running
700 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
701 which stop execution of the inferior whenever it executes an instruction
702 at any address within the specified range. See the "PowerPC Embedded"
703 section in the user manual for more details.
705 * New features in the GDB remote stub, GDBserver
707 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
708 and i686 LynxOS (version 5.x).
710 ** GDBserver is now supported on Blackfin Linux.
712 * New native configurations
714 ia64 HP-UX ia64-*-hpux*
718 Analog Devices, Inc. Blackfin Processor bfin-*
720 * Ada task switching is now supported on sparc-elf targets when
721 debugging a program using the Ravenscar Profile. For more information,
722 see the "Tasking Support when using the Ravenscar Profile" section
723 in the GDB user manual.
725 * Guile support was removed.
727 * New features in the GNU simulator
729 ** The --map-info flag lists all known core mappings.
731 ** CFI flashes may be simulated via the "cfi" device.
733 *** Changes in GDB 7.2
735 * Shared library support for remote targets by default
737 When GDB is configured for a generic, non-OS specific target, like
738 for example, --target=arm-eabi or one of the many *-*-elf targets,
739 GDB now queries remote stubs for loaded shared libraries using the
740 `qXfer:libraries:read' packet. Previously, shared library support
741 was always disabled for such configurations.
745 ** Argument Dependent Lookup (ADL)
747 In C++ ADL lookup directs function search to the namespaces of its
748 arguments even if the namespace has not been imported.
758 Here the compiler will search for `foo' in the namespace of 'b'
759 and find A::foo. GDB now supports this. This construct is commonly
760 used in the Standard Template Library for operators.
762 ** Improved User Defined Operator Support
764 In addition to member operators, GDB now supports lookup of operators
765 defined in a namespace and imported with a `using' directive, operators
766 defined in the global scope, operators imported implicitly from an
767 anonymous namespace, and the ADL operators mentioned in the previous
769 GDB now also supports proper overload resolution for all the previously
770 mentioned flavors of operators.
772 ** static const class members
774 Printing of static const class members that are initialized in the
775 class definition has been fixed.
777 * Windows Thread Information Block access.
779 On Windows targets, GDB now supports displaying the Windows Thread
780 Information Block (TIB) structure. This structure is visible either
781 by using the new command `info w32 thread-information-block' or, by
782 dereferencing the new convenience variable named `$_tlb', a
783 thread-specific pointer to the TIB. This feature is also supported
784 when remote debugging using GDBserver.
788 Static tracepoints are calls in the user program into a tracing
789 library. One such library is a port of the LTTng kernel tracer to
790 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
791 When debugging with GDBserver, GDB now supports combining the GDB
792 tracepoint machinery with such libraries. For example: the user can
793 use GDB to probe a static tracepoint marker (a call from the user
794 program into the tracing library) with the new "strace" command (see
795 "New commands" below). This creates a "static tracepoint" in the
796 breakpoint list, that can be manipulated with the same feature set
797 as fast and regular tracepoints. E.g., collect registers, local and
798 global variables, collect trace state variables, and define
799 tracepoint conditions. In addition, the user can collect extra
800 static tracepoint marker specific data, by collecting the new
801 $_sdata internal variable. When analyzing the trace buffer, you can
802 inspect $_sdata like any other variable available to GDB. For more
803 information, see the "Tracepoints" chapter in GDB user manual. New
804 remote packets have been defined to support static tracepoints, see
805 the "New remote packets" section below.
807 * Better reconstruction of tracepoints after disconnected tracing
809 GDB will attempt to download the original source form of tracepoint
810 definitions when starting a trace run, and then will upload these
811 upon reconnection to the target, resulting in a more accurate
812 reconstruction of the tracepoints that are in use on the target.
816 You can now exercise direct control over the ways that GDB can
817 affect your program. For instance, you can disallow the setting of
818 breakpoints, so that the program can run continuously (assuming
819 non-stop mode). In addition, the "observer" variable is available
820 to switch all of the different controls; in observer mode, GDB
821 cannot affect the target's behavior at all, which is useful for
822 tasks like diagnosing live systems in the field.
824 * The new convenience variable $_thread holds the number of the
831 Return the address of the Windows Thread Information Block of a given thread.
835 In response to several of the tracepoint packets, the target may now
836 also respond with a number of intermediate `qRelocInsn' request
837 packets before the final result packet, to have GDB handle
838 relocating an instruction to execute at a different address. This
839 is particularly useful for stubs that support fast tracepoints. GDB
840 reports support for this feature in the qSupported packet.
844 List static tracepoint markers in the target program.
848 List static tracepoint markers at a given address in the target
851 qXfer:statictrace:read
853 Read the static trace data collected (by a `collect $_sdata'
854 tracepoint action). The remote stub reports support for this packet
855 to gdb's qSupported query.
859 Send the current settings of GDB's permission flags.
863 Send part of the source (textual) form of a tracepoint definition,
864 which includes location, conditional, and action list.
866 * The source command now accepts a -s option to force searching for the
867 script in the source search path even if the script name specifies
870 * New features in the GDB remote stub, GDBserver
872 - GDBserver now support tracepoints (including fast tracepoints, and
873 static tracepoints). The feature is currently supported by the
874 i386-linux and amd64-linux builds. See the "Tracepoints support
875 in gdbserver" section in the manual for more information.
877 GDBserver JIT compiles the tracepoint's conditional agent
878 expression bytecode into native code whenever possible for low
879 overhead dynamic tracepoints conditionals. For such tracepoints,
880 an expression that examines program state is evaluated when the
881 tracepoint is reached, in order to determine whether to capture
882 trace data. If the condition is simple and false, processing the
883 tracepoint finishes very quickly and no data is gathered.
885 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
886 for static tracepoints support.
888 - GDBserver now supports x86_64 Windows 64-bit debugging.
890 * GDB now sends xmlRegisters= in qSupported packet to indicate that
891 it understands register description.
893 * The --batch flag now disables pagination and queries.
895 * X86 general purpose registers
897 GDB now supports reading/writing byte, word and double-word x86
898 general purpose registers directly. This means you can use, say,
899 $ah or $ax to refer, respectively, to the byte register AH and
900 16-bit word register AX that are actually portions of the 32-bit
901 register EAX or 64-bit register RAX.
903 * The `commands' command now accepts a range of breakpoints to modify.
904 A plain `commands' following a command that creates multiple
905 breakpoints affects all the breakpoints set by that command. This
906 applies to breakpoints set by `rbreak', and also applies when a
907 single `break' command creates multiple breakpoints (e.g.,
908 breakpoints on overloaded c++ functions).
910 * The `rbreak' command now accepts a filename specification as part of
911 its argument, limiting the functions selected by the regex to those
912 in the specified file.
914 * Support for remote debugging Windows and SymbianOS shared libraries
915 from Unix hosts has been improved. Non Windows GDB builds now can
916 understand target reported file names that follow MS-DOS based file
917 system semantics, such as file names that include drive letters and
918 use the backslash character as directory separator. This makes it
919 possible to transparently use the "set sysroot" and "set
920 solib-search-path" on Unix hosts to point as host copies of the
921 target's shared libraries. See the new command "set
922 target-file-system-kind" described below, and the "Commands to
923 specify files" section in the user manual for more information.
927 eval template, expressions...
928 Convert the values of one or more expressions under the control
929 of the string template to a command line, and call it.
931 set target-file-system-kind unix|dos-based|auto
932 show target-file-system-kind
933 Set or show the assumed file system kind for target reported file
936 save breakpoints <filename>
937 Save all current breakpoint definitions to a file suitable for use
938 in a later debugging session. To read the saved breakpoint
939 definitions, use the `source' command.
941 `save tracepoints' is a new alias for `save-tracepoints'. The latter
944 info static-tracepoint-markers
945 Display information about static tracepoint markers in the target.
947 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
948 Define a static tracepoint by probing a marker at the given
949 function, line, address, or marker ID.
953 Enable and disable observer mode.
955 set may-write-registers on|off
956 set may-write-memory on|off
957 set may-insert-breakpoints on|off
958 set may-insert-tracepoints on|off
959 set may-insert-fast-tracepoints on|off
960 set may-interrupt on|off
961 Set individual permissions for GDB effects on the target. Note that
962 some of these settings can have undesirable or surprising
963 consequences, particularly when changed in the middle of a session.
964 For instance, disabling the writing of memory can prevent
965 breakpoints from being inserted, cause single-stepping to fail, or
966 even crash your program, if you disable after breakpoints have been
967 inserted. However, GDB should not crash.
969 set record memory-query on|off
970 show record memory-query
971 Control whether to stop the inferior if memory changes caused
972 by an instruction cannot be recorded.
977 The disassemble command now supports "start,+length" form of two arguments.
981 ** GDB now provides a new directory location, called the python directory,
982 where Python scripts written for GDB can be installed. The location
983 of that directory is <data-directory>/python, where <data-directory>
984 is the GDB data directory. For more details, see section `Scripting
985 GDB using Python' in the manual.
987 ** The GDB Python API now has access to breakpoints, symbols, symbol
988 tables, program spaces, inferiors, threads and frame's code blocks.
989 Additionally, GDB Parameters can now be created from the API, and
990 manipulated via set/show in the CLI.
992 ** New functions gdb.target_charset, gdb.target_wide_charset,
993 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
995 ** New exception gdb.GdbError.
997 ** Pretty-printers are now also looked up in the current program space.
999 ** Pretty-printers can now be individually enabled and disabled.
1001 ** GDB now looks for names of Python scripts to auto-load in a
1002 special section named `.debug_gdb_scripts', in addition to looking
1003 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1005 * Tracepoint actions were unified with breakpoint commands. In particular,
1006 there are no longer differences in "info break" output for breakpoints and
1007 tracepoints and the "commands" command can be used for both tracepoints and
1008 regular breakpoints.
1012 ARM Symbian arm*-*-symbianelf*
1014 * D language support.
1015 GDB now supports debugging programs written in the D programming
1018 * GDB now supports the extended ptrace interface for PowerPC which is
1019 available since Linux kernel version 2.6.34. This automatically enables
1020 any hardware breakpoints and additional hardware watchpoints available in
1021 the processor. The old ptrace interface exposes just one hardware
1022 watchpoint and no hardware breakpoints.
1024 * GDB is now able to use the Data Value Compare (DVC) register available on
1025 embedded PowerPC processors to implement in hardware simple watchpoint
1026 conditions of the form:
1028 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1030 This works in native GDB running on Linux kernels with the extended ptrace
1031 interface mentioned above.
1033 *** Changes in GDB 7.1
1037 ** Namespace Support
1039 GDB now supports importing of namespaces in C++. This enables the
1040 user to inspect variables from imported namespaces. Support for
1041 namepace aliasing has also been added. So, if a namespace is
1042 aliased in the current scope (e.g. namepace C=A; ) the user can
1043 print variables using the alias (e.g. (gdb) print C::x).
1047 All known bugs relating to the printing of virtual base class were
1048 fixed. It is now possible to call overloaded static methods using a
1053 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1054 and reinterpret_cast<> are now handled by the C++ expression parser.
1058 Xilinx MicroBlaze microblaze-*-*
1063 Xilinx MicroBlaze microblaze
1066 * Multi-program debugging.
1068 GDB now has support for multi-program (a.k.a. multi-executable or
1069 multi-exec) debugging. This allows for debugging multiple inferiors
1070 simultaneously each running a different program under the same GDB
1071 session. See "Debugging Multiple Inferiors and Programs" in the
1072 manual for more information. This implied some user visible changes
1073 in the multi-inferior support. For example, "info inferiors" now
1074 lists inferiors that are not running yet or that have exited
1075 already. See also "New commands" and "New options" below.
1077 * New tracing features
1079 GDB's tracepoint facility now includes several new features:
1081 ** Trace state variables
1083 GDB tracepoints now include support for trace state variables, which
1084 are variables managed by the target agent during a tracing
1085 experiment. They are useful for tracepoints that trigger each
1086 other, so for instance one tracepoint can count hits in a variable,
1087 and then a second tracepoint has a condition that is true when the
1088 count reaches a particular value. Trace state variables share the
1089 $-syntax of GDB convenience variables, and can appear in both
1090 tracepoint actions and condition expressions. Use the "tvariable"
1091 command to create, and "info tvariables" to view; see "Trace State
1092 Variables" in the manual for more detail.
1096 GDB now includes an option for defining fast tracepoints, which
1097 targets may implement more efficiently, such as by installing a jump
1098 into the target agent rather than a trap instruction. The resulting
1099 speedup can be by two orders of magnitude or more, although the
1100 tradeoff is that some program locations on some target architectures
1101 might not allow fast tracepoint installation, for instance if the
1102 instruction to be replaced is shorter than the jump. To request a
1103 fast tracepoint, use the "ftrace" command, with syntax identical to
1104 the regular trace command.
1106 ** Disconnected tracing
1108 It is now possible to detach GDB from the target while it is running
1109 a trace experiment, then reconnect later to see how the experiment
1110 is going. In addition, a new variable disconnected-tracing lets you
1111 tell the target agent whether to continue running a trace if the
1112 connection is lost unexpectedly.
1116 GDB now has the ability to save the trace buffer into a file, and
1117 then use that file as a target, similarly to you can do with
1118 corefiles. You can select trace frames, print data that was
1119 collected in them, and use tstatus to display the state of the
1120 tracing run at the moment that it was saved. To create a trace
1121 file, use "tsave <filename>", and to use it, do "target tfile
1124 ** Circular trace buffer
1126 You can ask the target agent to handle the trace buffer as a
1127 circular buffer, discarding the oldest trace frames to make room for
1128 newer ones, by setting circular-trace-buffer to on. This feature may
1129 not be available for all target agents.
1134 The disassemble command, when invoked with two arguments, now requires
1135 the arguments to be comma-separated.
1138 The info variables command now displays variable definitions. Files
1139 which only declare a variable are not shown.
1142 The source command is now capable of sourcing Python scripts.
1143 This feature is dependent on the debugger being build with Python
1146 Related to this enhancement is also the introduction of a new command
1147 "set script-extension" (see below).
1149 * New commands (for set/show, see "New options" below)
1151 record save [<FILENAME>]
1152 Save a file (in core file format) containing the process record
1153 execution log for replay debugging at a later time.
1155 record restore <FILENAME>
1156 Restore the process record execution log that was saved at an
1157 earlier time, for replay debugging.
1159 add-inferior [-copies <N>] [-exec <FILENAME>]
1162 clone-inferior [-copies <N>] [ID]
1163 Make a new inferior ready to execute the same program another
1164 inferior has loaded.
1169 maint info program-spaces
1170 List the program spaces loaded into GDB.
1172 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1173 show remote interrupt-sequence
1174 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1175 as the sequence to the remote target in order to interrupt the execution.
1176 Ctrl-C is a default. Some system prefers BREAK which is high level of
1177 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1178 Magic SysRq g. It is BREAK signal and character 'g'.
1180 set remote interrupt-on-connect [on | off]
1181 show remote interrupt-on-connect
1182 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1183 remote target when gdb connects to it. This is needed when you debug
1186 set remotebreak [on | off]
1188 Deprecated. Use "set/show remote interrupt-sequence" instead.
1190 tvariable $NAME [ = EXP ]
1191 Create or modify a trace state variable.
1194 List trace state variables and their values.
1196 delete tvariable $NAME ...
1197 Delete one or more trace state variables.
1200 Evaluate the given expressions without collecting anything into the
1201 trace buffer. (Valid in tracepoint actions only.)
1203 ftrace FN / FILE:LINE / *ADDR
1204 Define a fast tracepoint at the given function, line, or address.
1206 * New expression syntax
1208 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1209 GDB now parses 0b101010 identically with 42.
1213 set follow-exec-mode new|same
1214 show follow-exec-mode
1215 Control whether GDB reuses the same inferior across an exec call or
1216 creates a new one. This is useful to be able to restart the old
1217 executable after the inferior having done an exec call.
1219 set default-collect EXPR, ...
1220 show default-collect
1221 Define a list of expressions to be collected at each tracepoint.
1222 This is a useful way to ensure essential items are not overlooked,
1223 such as registers or a critical global variable.
1225 set disconnected-tracing
1226 show disconnected-tracing
1227 If set to 1, the target is instructed to continue tracing if it
1228 loses its connection to GDB. If 0, the target is to stop tracing
1231 set circular-trace-buffer
1232 show circular-trace-buffer
1233 If set to on, the target is instructed to use a circular trace buffer
1234 and discard the oldest trace frames instead of stopping the trace due
1235 to a full trace buffer. If set to off, the trace stops when the buffer
1236 fills up. Some targets may not support this.
1238 set script-extension off|soft|strict
1239 show script-extension
1240 If set to "off", the debugger does not perform any script language
1241 recognition, and all sourced files are assumed to be GDB scripts.
1242 If set to "soft" (the default), files are sourced according to
1243 filename extension, falling back to GDB scripts if the first
1245 If set to "strict", files are sourced according to filename extension.
1247 set ada trust-PAD-over-XVS on|off
1248 show ada trust-PAD-over-XVS
1249 If off, activate a workaround against a bug in the debugging information
1250 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1251 the GCC sources for more information about the GNAT encoding and
1252 PAD types in particular). It is always safe to set this option to
1253 off, but this introduces a slight performance penalty. The default
1256 * Python API Improvements
1258 ** GDB provides the new class gdb.LazyString. This is useful in
1259 some pretty-printing cases. The new method gdb.Value.lazy_string
1260 provides a simple way to create objects of this type.
1262 ** The fields returned by gdb.Type.fields now have an
1263 `is_base_class' attribute.
1265 ** The new method gdb.Type.range returns the range of an array type.
1267 ** The new method gdb.parse_and_eval can be used to parse and
1268 evaluate an expression.
1270 * New remote packets
1273 Define a trace state variable.
1276 Get the current value of a trace state variable.
1279 Set desired tracing behavior upon disconnection.
1282 Set the trace buffer to be linear or circular.
1285 Get data about the tracepoints currently in use.
1289 Process record now works correctly with hardware watchpoints.
1291 Multiple bug fixes have been made to the mips-irix port, making it
1292 much more reliable. In particular:
1293 - Debugging threaded applications is now possible again. Previously,
1294 GDB would hang while starting the program, or while waiting for
1295 the program to stop at a breakpoint.
1296 - Attaching to a running process no longer hangs.
1297 - An error occurring while loading a core file has been fixed.
1298 - Changing the value of the PC register now works again. This fixes
1299 problems observed when using the "jump" command, or when calling
1300 a function from GDB, or even when assigning a new value to $pc.
1301 - With the "finish" and "return" commands, the return value for functions
1302 returning a small array is now correctly printed.
1303 - It is now possible to break on shared library code which gets executed
1304 during a shared library init phase (code executed while executing
1305 their .init section). Previously, the breakpoint would have no effect.
1306 - GDB is now able to backtrace through the signal handler for
1307 non-threaded programs.
1309 PIE (Position Independent Executable) programs debugging is now supported.
1310 This includes debugging execution of PIC (Position Independent Code) shared
1311 libraries although for that, it should be possible to run such libraries as an
1314 *** Changes in GDB 7.0
1316 * GDB now has an interface for JIT compilation. Applications that
1317 dynamically generate code can create symbol files in memory and register
1318 them with GDB. For users, the feature should work transparently, and
1319 for JIT developers, the interface is documented in the GDB manual in the
1320 "JIT Compilation Interface" chapter.
1322 * Tracepoints may now be conditional. The syntax is as for
1323 breakpoints; either an "if" clause appended to the "trace" command,
1324 or the "condition" command is available. GDB sends the condition to
1325 the target for evaluation using the same bytecode format as is used
1326 for tracepoint actions.
1328 * The disassemble command now supports: an optional /r modifier, print the
1329 raw instructions in hex as well as in symbolic form, and an optional /m
1330 modifier to print mixed source+assembly.
1332 * Process record and replay
1334 In a architecture environment that supports ``process record and
1335 replay'', ``process record and replay'' target can record a log of
1336 the process execution, and replay it with both forward and reverse
1339 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1340 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1341 set execution-direction {forward|reverse}, for targets that support
1344 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1345 feature is available with a native GDB running on kernel version
1348 * GDB now has support for multi-byte and wide character sets on the
1349 target. Strings whose character type is wchar_t, char16_t, or
1350 char32_t are now correctly printed. GDB supports wide- and unicode-
1351 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1352 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1353 `printf'. This feature requires iconv to work properly; if your
1354 system does not have a working iconv, GDB can use GNU libiconv. See
1355 the installation instructions for more information.
1357 * GDB now supports automatic retrieval of shared library files from
1358 remote targets. To use this feature, specify a system root that begins
1359 with the `remote:' prefix, either via the `set sysroot' command or via
1360 the `--with-sysroot' configure-time option.
1362 * "info sharedlibrary" now takes an optional regex of libraries to show,
1363 and it now reports if a shared library has no debugging information.
1365 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1366 now complete on file names.
1368 * When completing in expressions, gdb will attempt to limit
1369 completions to allowable structure or union fields, where appropriate.
1370 For instance, consider:
1372 # struct example { int f1; double f2; };
1373 # struct example variable;
1376 If the user types TAB at the end of this command line, the available
1377 completions will be "f1" and "f2".
1379 * Inlined functions are now supported. They show up in backtraces, and
1380 the "step", "next", and "finish" commands handle them automatically.
1382 * GDB now supports the token-splicing (##) and stringification (#)
1383 operators when expanding macros. It also supports variable-arity
1386 * GDB now supports inspecting extra signal information, exported by
1387 the new $_siginfo convenience variable. The feature is currently
1388 implemented on linux ARM, i386 and amd64.
1390 * GDB can now display the VFP floating point registers and NEON vector
1391 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1392 can provide these registers (requires Linux 2.6.30 or later). Remote
1393 and simulator targets may also provide them.
1395 * New remote packets
1398 Search memory for a sequence of bytes.
1401 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1402 operation over reliable transport links. Use of this packet is
1403 controlled by the `set remote noack-packet' command.
1406 Kill the process with the specified process ID. Use this in preference
1407 to `k' when multiprocess protocol extensions are supported.
1410 Obtains additional operating system information
1414 Read or write additional signal information.
1416 * Removed remote protocol undocumented extension
1418 An undocumented extension to the remote protocol's `S' stop reply
1419 packet that permited the stub to pass a process id was removed.
1420 Remote servers should use the `T' stop reply packet instead.
1422 * GDB now supports multiple function calling conventions according to the
1423 DWARF-2 DW_AT_calling_convention function attribute.
1425 * The SH target utilizes the aforementioned change to distinguish between gcc
1426 and Renesas calling convention. It also adds the new CLI commands
1427 `set/show sh calling-convention'.
1429 * GDB can now read compressed debug sections, as produced by GNU gold
1430 with the --compress-debug-sections=zlib flag.
1432 * 64-bit core files are now supported on AIX.
1434 * Thread switching is now supported on Tru64.
1436 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1437 which will be allocated using malloc later in program execution.
1439 * The qXfer:libraries:read remote procotol packet now allows passing a
1440 list of section offsets.
1442 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1443 conditions handling signals delivered during attach or thread creation
1444 have also been fixed.
1446 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1447 From the user's standpoint, all unqualified instances of True and False
1448 are treated as the standard definitions, regardless of context.
1450 * GDB now parses C++ symbol and type names more flexibly. For
1453 template<typename T> class C { };
1456 GDB will now correctly handle all of:
1458 ptype C<char const *>
1459 ptype C<char const*>
1460 ptype C<const char *>
1461 ptype C<const char*>
1463 * New features in the GDB remote stub, gdbserver
1465 - The "--wrapper" command-line argument tells gdbserver to use a
1466 wrapper program to launch programs for debugging.
1468 - On PowerPC and S/390 targets, it is now possible to use a single
1469 gdbserver executable to debug both 32-bit and 64-bit programs.
1470 (This requires gdbserver itself to be built as a 64-bit executable.)
1472 - gdbserver uses the new noack protocol mode for TCP connections to
1473 reduce communications latency, if also supported and enabled in GDB.
1475 - Support for the sparc64-linux-gnu target is now included in
1478 - The amd64-linux build of gdbserver now supports debugging both
1479 32-bit and 64-bit programs.
1481 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1482 now support hardware watchpoints, and will use them automatically
1487 GDB now has support for scripting using Python. Whether this is
1488 available is determined at configure time.
1490 New GDB commands can now be written in Python.
1492 * Ada tasking support
1494 Ada tasks can now be inspected in GDB. The following commands have
1498 Print the list of Ada tasks.
1500 Print detailed information about task number N.
1502 Print the task number of the current task.
1504 Switch the context of debugging to task number N.
1506 * Support for user-defined prefixed commands. The "define" command can
1507 add new commands to existing prefixes, e.g. "target".
1509 * Multi-inferior, multi-process debugging.
1511 GDB now has generalized support for multi-inferior debugging. See
1512 "Debugging Multiple Inferiors" in the manual for more information.
1513 Although availability still depends on target support, the command
1514 set is more uniform now. The GNU/Linux specific multi-forks support
1515 has been migrated to this new framework. This implied some user
1516 visible changes; see "New commands" and also "Removed commands"
1519 * Target descriptions can now describe the target OS ABI. See the
1520 "Target Description Format" section in the user manual for more
1523 * Target descriptions can now describe "compatible" architectures
1524 to indicate that the target can execute applications for a different
1525 architecture in addition to those for the main target architecture.
1526 See the "Target Description Format" section in the user manual for
1529 * Multi-architecture debugging.
1531 GDB now includes general supports for debugging applications on
1532 hybrid systems that use more than one single processor architecture
1533 at the same time. Each such hybrid architecture still requires
1534 specific support to be added. The only hybrid architecture supported
1535 in this version of GDB is the Cell Broadband Engine.
1537 * GDB now supports integrated debugging of Cell/B.E. applications that
1538 use both the PPU and SPU architectures. To enable support for hybrid
1539 Cell/B.E. debugging, you need to configure GDB to support both the
1540 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1541 --enable-targets configure option.
1543 * Non-stop mode debugging.
1545 For some targets, GDB now supports an optional mode of operation in
1546 which you can examine stopped threads while other threads continue
1547 to execute freely. This is referred to as non-stop mode, with the
1548 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1549 section in the user manual for more information.
1551 To be able to support remote non-stop debugging, a remote stub needs
1552 to implement the non-stop mode remote protocol extensions, as
1553 described in the "Remote Non-Stop" section of the user manual. The
1554 GDB remote stub, gdbserver, has been adjusted to support these
1555 extensions on linux targets.
1557 * New commands (for set/show, see "New options" below)
1559 catch syscall [NAME(S) | NUMBER(S)]
1560 Catch system calls. Arguments, which should be names of system
1561 calls or their numbers, mean catch only those syscalls. Without
1562 arguments, every syscall will be caught. When the inferior issues
1563 any of the specified syscalls, GDB will stop and announce the system
1564 call, both when it is called and when its call returns. This
1565 feature is currently available with a native GDB running on the
1566 Linux Kernel, under the following architectures: x86, x86_64,
1567 PowerPC and PowerPC64.
1569 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1571 Search memory for a sequence of bytes.
1573 maint set python print-stack
1574 maint show python print-stack
1575 Show a stack trace when an error is encountered in a Python script.
1578 Invoke CODE by passing it to the Python interpreter.
1583 These allow macros to be defined, undefined, and listed
1587 Show operating system information about processes.
1590 List the inferiors currently under GDB's control.
1593 Switch focus to inferior number NUM.
1596 Detach from inferior number NUM.
1599 Kill inferior number NUM.
1603 set spu stop-on-load
1604 show spu stop-on-load
1605 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1607 set spu auto-flush-cache
1608 show spu auto-flush-cache
1609 Control whether to automatically flush the software-managed cache
1610 during Cell/B.E. debugging.
1612 set sh calling-convention
1613 show sh calling-convention
1614 Control the calling convention used when calling SH target functions.
1617 show debug timestamp
1618 Control display of timestamps with GDB debugging output.
1620 set disassemble-next-line
1621 show disassemble-next-line
1622 Control display of disassembled source lines or instructions when
1625 set remote noack-packet
1626 show remote noack-packet
1627 Set/show the use of remote protocol QStartNoAckMode packet. See above
1628 under "New remote packets."
1630 set remote query-attached-packet
1631 show remote query-attached-packet
1632 Control use of remote protocol `qAttached' (query-attached) packet.
1634 set remote read-siginfo-object
1635 show remote read-siginfo-object
1636 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
1639 set remote write-siginfo-object
1640 show remote write-siginfo-object
1641 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
1644 set remote reverse-continue
1645 show remote reverse-continue
1646 Control use of remote protocol 'bc' (reverse-continue) packet.
1648 set remote reverse-step
1649 show remote reverse-step
1650 Control use of remote protocol 'bs' (reverse-step) packet.
1652 set displaced-stepping
1653 show displaced-stepping
1654 Control displaced stepping mode. Displaced stepping is a way to
1655 single-step over breakpoints without removing them from the debuggee.
1656 Also known as "out-of-line single-stepping".
1659 show debug displaced
1660 Control display of debugging info for displaced stepping.
1662 maint set internal-error
1663 maint show internal-error
1664 Control what GDB does when an internal error is detected.
1666 maint set internal-warning
1667 maint show internal-warning
1668 Control what GDB does when an internal warning is detected.
1673 Use a wrapper program to launch programs for debugging.
1675 set multiple-symbols (all|ask|cancel)
1676 show multiple-symbols
1677 The value of this variable can be changed to adjust the debugger behavior
1678 when an expression or a breakpoint location contains an ambiguous symbol
1679 name (an overloaded function name, for instance).
1681 set breakpoint always-inserted
1682 show breakpoint always-inserted
1683 Keep breakpoints always inserted in the target, as opposed to inserting
1684 them when resuming the target, and removing them when the target stops.
1685 This option can improve debugger performance on slow remote targets.
1687 set arm fallback-mode (arm|thumb|auto)
1688 show arm fallback-mode
1689 set arm force-mode (arm|thumb|auto)
1691 These commands control how ARM GDB determines whether instructions
1692 are ARM or Thumb. The default for both settings is auto, which uses
1693 the current CPSR value for instructions without symbols; previous
1694 versions of GDB behaved as if "set arm fallback-mode arm".
1696 set disable-randomization
1697 show disable-randomization
1698 Standalone programs run with the virtual address space randomization enabled
1699 by default on some platforms. This option keeps the addresses stable across
1700 multiple debugging sessions.
1704 Control whether other threads are stopped or not when some thread hits
1709 Requests that asynchronous execution is enabled in the target, if available.
1710 In this case, it's possible to resume target in the background, and interact
1711 with GDB while the target is running. "show target-async" displays the
1712 current state of asynchronous execution of the target.
1714 set target-wide-charset
1715 show target-wide-charset
1716 The target-wide-charset is the name of the character set that GDB
1717 uses when printing characters whose type is wchar_t.
1719 set tcp auto-retry (on|off)
1721 set tcp connect-timeout
1722 show tcp connect-timeout
1723 These commands allow GDB to retry failed TCP connections to a remote stub
1724 with a specified timeout period; this is useful if the stub is launched
1725 in parallel with GDB but may not be ready to accept connections immediately.
1727 set libthread-db-search-path
1728 show libthread-db-search-path
1729 Control list of directories which GDB will search for appropriate
1732 set schedule-multiple (on|off)
1733 show schedule-multiple
1734 Allow GDB to resume all threads of all processes or only threads of
1735 the current process.
1739 Use more aggressive caching for accesses to the stack. This improves
1740 performance of remote debugging (particularly backtraces) without
1741 affecting correctness.
1743 set interactive-mode (on|off|auto)
1744 show interactive-mode
1745 Control whether GDB runs in interactive mode (on) or not (off).
1746 When in interactive mode, GDB waits for the user to answer all
1747 queries. Otherwise, GDB does not wait and assumes the default
1748 answer. When set to auto (the default), GDB determines which
1749 mode to use based on the stdin settings.
1754 For program forks, this is replaced by the new more generic `info
1755 inferiors' command. To list checkpoints, you can still use the
1756 `info checkpoints' command, which was an alias for the `info forks'
1760 Replaced by the new `inferior' command. To switch between
1761 checkpoints, you can still use the `restart' command, which was an
1762 alias for the `fork' command.
1765 This is removed, since some targets don't have a notion of
1766 processes. To switch between processes, you can still use the
1767 `inferior' command using GDB's own inferior number.
1770 For program forks, this is replaced by the new more generic `kill
1771 inferior' command. To delete a checkpoint, you can still use the
1772 `delete checkpoint' command, which was an alias for the `delete
1776 For program forks, this is replaced by the new more generic `detach
1777 inferior' command. To detach a checkpoint, you can still use the
1778 `detach checkpoint' command, which was an alias for the `detach
1781 * New native configurations
1783 x86/x86_64 Darwin i[34567]86-*-darwin*
1785 x86_64 MinGW x86_64-*-mingw*
1789 Lattice Mico32 lm32-*
1790 x86 DICOS i[34567]86-*-dicos*
1791 x86_64 DICOS x86_64-*-dicos*
1794 * The GDB remote stub, gdbserver, now supports x86 Windows CE
1795 (mingw32ce) debugging.
1801 These commands were actually not implemented on any target.
1803 *** Changes in GDB 6.8
1805 * New native configurations
1807 NetBSD/hppa hppa*-*netbsd*
1808 Xtensa GNU/Linux xtensa*-*-linux*
1812 NetBSD/hppa hppa*-*-netbsd*
1813 Xtensa GNU/Lunux xtensa*-*-linux*
1815 * Change in command line behavior -- corefiles vs. process ids.
1817 When the '-p NUMBER' or '--pid NUMBER' options are used, and
1818 attaching to process NUMBER fails, GDB no longer attempts to open a
1819 core file named NUMBER. Attaching to a program using the -c option
1820 is no longer supported. Instead, use the '-p' or '--pid' options.
1822 * GDB can now be built as a native debugger for debugging Windows x86
1823 (mingw32) Portable Executable (PE) programs.
1825 * Pending breakpoints no longer change their number when their address
1828 * GDB now supports breakpoints with multiple locations,
1829 including breakpoints on C++ constructors, inside C++ templates,
1830 and in inlined functions.
1832 * GDB's ability to debug optimized code has been improved. GDB more
1833 accurately identifies function bodies and lexical blocks that occupy
1834 more than one contiguous range of addresses.
1836 * Target descriptions can now describe registers for PowerPC.
1838 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
1839 registers on PowerPC targets.
1841 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
1842 targets even when the libthread_db library is not available.
1844 * The GDB remote stub, gdbserver, now supports the new file transfer
1845 commands (remote put, remote get, and remote delete).
1847 * The GDB remote stub, gdbserver, now supports run and attach in
1848 extended-remote mode.
1850 * hppa*64*-*-hpux11* target broken
1851 The debugger is unable to start a program and fails with the following
1852 error: "Error trying to get information about dynamic linker".
1853 The gdb-6.7 release is also affected.
1855 * GDB now supports the --enable-targets= configure option to allow
1856 building a single GDB executable that supports multiple remote
1857 target architectures.
1859 * GDB now supports debugging C and C++ programs which use the
1860 Decimal Floating Point extension. In addition, the PowerPC target
1861 now has a set of pseudo-registers to inspect decimal float values
1862 stored in two consecutive float registers.
1864 * The -break-insert MI command can optionally create pending
1867 * Improved support for debugging Ada
1868 Many improvements to the Ada language support have been made. These
1870 - Better support for Ada2005 interface types
1871 - Improved handling of arrays and slices in general
1872 - Better support for Taft-amendment types
1873 - The '{type} ADDRESS' expression is now allowed on the left hand-side
1875 - Improved command completion in Ada
1878 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
1883 set print frame-arguments (all|scalars|none)
1884 show print frame-arguments
1885 The value of this variable can be changed to control which argument
1886 values should be printed by the debugger when displaying a frame.
1891 Transfer files to and from a remote target, and delete remote files.
1898 Transfer files to and from a remote target, and delete remote files.
1900 * New remote packets
1907 Open, close, read, write, and delete files on the remote system.
1910 Attach to an existing process on the remote system, in extended-remote
1914 Run a new process on the remote system, in extended-remote mode.
1916 *** Changes in GDB 6.7
1918 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
1919 bfd, libiberty and opcodes, as revealed by static analysis donated by
1920 Coverity, Inc. (http://scan.coverity.com).
1922 * When looking up multiply-defined global symbols, GDB will now prefer the
1923 symbol definition in the current shared library if it was built using the
1924 -Bsymbolic linker option.
1926 * When the Text User Interface (TUI) is not configured, GDB will now
1927 recognize the -tui command-line option and print a message that the TUI
1930 * The GDB remote stub, gdbserver, now has lower overhead for high
1931 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
1933 * GDB for MIPS targets now autodetects whether a remote target provides
1934 32-bit or 64-bit register values.
1936 * Support for C++ member pointers has been improved.
1938 * GDB now understands XML target descriptions, which specify the
1939 target's overall architecture. GDB can read a description from
1940 a local file or over the remote serial protocol.
1942 * Vectors of single-byte data use a new integer type which is not
1943 automatically displayed as character or string data.
1945 * The /s format now works with the print command. It displays
1946 arrays of single-byte integers and pointers to single-byte integers
1949 * Target descriptions can now describe target-specific registers,
1950 for architectures which have implemented the support (currently
1951 only ARM, M68K, and MIPS).
1953 * GDB and the GDB remote stub, gdbserver, now support the XScale
1956 * The GDB remote stub, gdbserver, has been updated to support
1957 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
1958 has been rewritten to use the standard GDB remote protocol.
1960 * GDB can now step into C++ functions which are called through thunks.
1962 * GDB for the Cell/B.E. SPU now supports overlay debugging.
1964 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
1965 layout. It also supports a TextSeg= and DataSeg= response when only
1966 segment base addresses (rather than offsets) are available.
1968 * The /i format now outputs any trailing branch delay slot instructions
1969 immediately following the last instruction within the count specified.
1971 * The GDB remote protocol "T" stop reply packet now supports a
1972 "library" response. Combined with the new "qXfer:libraries:read"
1973 packet, this response allows GDB to debug shared libraries on targets
1974 where the operating system manages the list of loaded libraries (e.g.
1975 Windows and SymbianOS).
1977 * The GDB remote stub, gdbserver, now supports dynamic link libraries
1978 (DLLs) on Windows and Windows CE targets.
1980 * GDB now supports a faster verification that a .debug file matches its binary
1981 according to its build-id signature, if the signature is present.
1987 Enable or disable hardware flow control (RTS/CTS) on the serial port
1988 when debugging using remote targets.
1990 set mem inaccessible-by-default
1991 show mem inaccessible-by-default
1992 If the target supplies a memory map, for instance via the remote
1993 protocol's "qXfer:memory-map:read" packet, setting this variable
1994 prevents GDB from accessing memory outside the memory map. This
1995 is useful for targets with memory mapped registers or which react
1996 badly to accesses of unmapped address space.
1998 set breakpoint auto-hw
1999 show breakpoint auto-hw
2000 If the target supplies a memory map, for instance via the remote
2001 protocol's "qXfer:memory-map:read" packet, setting this variable
2002 lets GDB use hardware breakpoints automatically for memory regions
2003 where it can not use software breakpoints. This covers both the
2004 "break" command and internal breakpoints used for other commands
2005 including "next" and "finish".
2008 catch exception unhandled
2009 Stop the program execution when Ada exceptions are raised.
2012 Stop the program execution when an Ada assertion failed.
2016 Set an alternate system root for target files. This is a more
2017 general version of "set solib-absolute-prefix", which is now
2018 an alias to "set sysroot".
2021 Provide extended SPU facility status information. This set of
2022 commands is available only when debugging the Cell/B.E. SPU
2025 * New native configurations
2027 OpenBSD/sh sh*-*openbsd*
2030 unset tdesc filename
2032 Use the specified local file as an XML target description, and do
2033 not query the target for its built-in description.
2037 OpenBSD/sh sh*-*-openbsd*
2038 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2039 Toshiba Media Processor mep-elf
2041 * New remote packets
2044 Ignore the specified signals; pass them directly to the debugged program
2045 without stopping other threads or reporting them to GDB.
2047 qXfer:features:read:
2048 Read an XML target description from the target, which describes its
2053 Read or write contents of an spufs file on the target system. These
2054 packets are available only on the Cell/B.E. SPU architecture.
2056 qXfer:libraries:read:
2057 Report the loaded shared libraries. Combined with new "T" packet
2058 response, this packet allows GDB to debug shared libraries on
2059 targets where the operating system manages the list of loaded
2060 libraries (e.g. Windows and SymbianOS).
2064 Support for these obsolete configurations has been removed.
2072 i[34567]86-*-lynxos*
2073 i[34567]86-*-netware*
2074 i[34567]86-*-sco3.2v5*
2075 i[34567]86-*-sco3.2v4*
2077 i[34567]86-*-sysv4.2*
2080 i[34567]86-*-unixware2*
2081 i[34567]86-*-unixware*
2090 * Other removed features
2097 Various m68k-only ROM monitors.
2104 Various Renesas ROM monitors and debugging interfaces for SH and
2109 Support for a Macraigor serial interface to on-chip debugging.
2110 GDB does not directly support the newer parallel or USB
2115 A debug information format. The predecessor to DWARF 2 and
2116 DWARF 3, which are still supported.
2118 Support for the HP aCC compiler on HP-UX/PA-RISC
2120 SOM-encapsulated symbolic debugging information, automatic
2121 invocation of pxdb, and the aCC custom C++ ABI. This does not
2122 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2123 with aCC can still be debugged on an assembly level.
2125 MIPS ".pdr" sections
2127 A MIPS-specific format used to describe stack frame layout
2128 in debugging information.
2132 GDB could work with an older version of Guile to debug
2133 the interpreter and Scheme programs running in it.
2135 set mips stack-arg-size
2136 set mips saved-gpreg-size
2138 Use "set mips abi" to control parameter passing for MIPS.
2140 *** Changes in GDB 6.6
2145 Cell Broadband Engine SPU spu-elf
2147 * GDB can now be configured as a cross-debugger targeting native Windows
2148 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2149 running on a Windows system over TCP/IP to debug Windows programs.
2151 * The GDB remote stub, gdbserver, has been updated to support Windows and
2152 Cygwin debugging. Both single-threaded and multi-threaded programs are
2155 * The "set trust-readonly-sections" command works again. This command was
2156 broken in GDB 6.3, 6.4, and 6.5.
2158 * The "load" command now supports writing to flash memory, if the remote
2159 stub provides the required support.
2161 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2162 longer requires symbolic debug information (e.g. DWARF-2).
2167 unset substitute-path
2168 show substitute-path
2169 Manage a list of substitution rules that GDB uses to rewrite the name
2170 of the directories where the sources are located. This can be useful
2171 for instance when the sources were moved to a different location
2172 between compilation and debugging.
2176 Print each CLI command as it is executed. Each command is prefixed with
2177 a number of `+' symbols representing the nesting depth.
2178 The source command now has a `-v' option to enable the same feature.
2182 The ARM Demon monitor support (RDP protocol, "target rdp").
2184 Kernel Object Display, an embedded debugging feature which only worked with
2185 an obsolete version of Cisco IOS.
2187 The 'set download-write-size' and 'show download-write-size' commands.
2189 * New remote packets
2192 Tell a stub about GDB client features, and request remote target features.
2193 The first feature implemented is PacketSize, which allows the target to
2194 specify the size of packets it can handle - to minimize the number of
2195 packets required and improve performance when connected to a remote
2199 Fetch an OS auxilliary vector from the remote stub. This packet is a
2200 more efficient replacement for qPart:auxv:read.
2202 qXfer:memory-map:read:
2203 Fetch a memory map from the remote stub, including information about
2204 RAM, ROM, and flash memory devices.
2209 Erase and program a flash memory device.
2211 * Removed remote packets
2214 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2215 used it, and only gdbserver implemented it.
2217 *** Changes in GDB 6.5
2221 Renesas M32C/M16C m32c-elf
2223 Morpho Technologies ms1 ms1-elf
2227 init-if-undefined Initialize a convenience variable, but
2228 only if it doesn't already have a value.
2230 The following commands are presently only implemented for native GNU/Linux:
2232 checkpoint Save a snapshot of the program state.
2234 restart <n> Return the program state to a
2235 previously saved state.
2237 info checkpoints List currently saved checkpoints.
2239 delete-checkpoint <n> Delete a previously saved checkpoint.
2241 set|show detach-on-fork Tell gdb whether to detach from a newly
2242 forked process, or to keep debugging it.
2244 info forks List forks of the user program that
2245 are available to be debugged.
2247 fork <n> Switch to debugging one of several
2248 forks of the user program that are
2249 available to be debugged.
2251 delete-fork <n> Delete a fork from the list of forks
2252 that are available to be debugged (and
2253 kill the forked process).
2255 detach-fork <n> Delete a fork from the list of forks
2256 that are available to be debugged (and
2257 allow the process to continue).
2261 Morpho Technologies ms2 ms1-elf
2263 * Improved Windows host support
2265 GDB now builds as a cross debugger hosted on i686-mingw32, including
2266 native console support, and remote communications using either
2267 network sockets or serial ports.
2269 * Improved Modula-2 language support
2271 GDB can now print most types in the Modula-2 syntax. This includes:
2272 basic types, set types, record types, enumerated types, range types,
2273 pointer types and ARRAY types. Procedure var parameters are correctly
2274 printed and hexadecimal addresses and character constants are also
2275 written in the Modula-2 syntax. Best results can be obtained by using
2276 GNU Modula-2 together with the -gdwarf-2 command line option.
2280 The ARM rdi-share module.
2282 The Netware NLM debug server.
2284 *** Changes in GDB 6.4
2286 * New native configurations
2288 OpenBSD/arm arm*-*-openbsd*
2289 OpenBSD/mips64 mips64-*-openbsd*
2293 Morpho Technologies ms1 ms1-elf
2295 * New command line options
2297 --batch-silent As for --batch, but totally silent.
2298 --return-child-result The debugger will exist with the same value
2299 the child (debugged) program exited with.
2300 --eval-command COMMAND, -ex COMMAND
2301 Execute a single GDB CLI command. This may be
2302 specified multiple times and in conjunction
2303 with the --command (-x) option.
2305 * Deprecated commands removed
2307 The following commands, that were deprecated in 2000, have been
2311 set|show arm disassembly-flavor set|show arm disassembler
2312 othernames set arm disassembler
2313 set|show remotedebug set|show debug remote
2314 set|show archdebug set|show debug arch
2315 set|show eventdebug set|show debug event
2318 * New BSD user-level threads support
2320 It is now possible to debug programs using the user-level threads
2321 library on OpenBSD and FreeBSD. Currently supported (target)
2324 FreeBSD/amd64 x86_64-*-freebsd*
2325 FreeBSD/i386 i386-*-freebsd*
2326 OpenBSD/i386 i386-*-openbsd*
2328 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2329 are not yet supported.
2331 * New support for Matsushita MN10300 w/sim added
2332 (Work in progress). mn10300-elf.
2334 * REMOVED configurations and files
2336 VxWorks and the XDR protocol *-*-vxworks
2337 Motorola MCORE mcore-*-*
2338 National Semiconductor NS32000 ns32k-*-*
2340 * New "set print array-indexes" command
2342 After turning this setting "on", GDB prints the index of each element
2343 when displaying arrays. The default is "off" to preserve the previous
2346 * VAX floating point support
2348 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2350 * User-defined command support
2352 In addition to using $arg0..$arg9 for argument passing, it is now possible
2353 to use $argc to determine now many arguments have been passed. See the
2354 section on user-defined commands in the user manual for more information.
2356 *** Changes in GDB 6.3:
2358 * New command line option
2360 GDB now accepts -l followed by a number to set the timeout for remote
2363 * GDB works with GCC -feliminate-dwarf2-dups
2365 GDB now supports a more compact representation of DWARF-2 debug
2366 information using DW_FORM_ref_addr references. These are produced
2367 by GCC with the option -feliminate-dwarf2-dups and also by some
2368 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2369 to use -feliminate-dwarf2-dups.
2371 * Internationalization
2373 When supported by the host system, GDB will be built with
2374 internationalization (libintl). The task of marking up the sources is
2375 continued, we're looking forward to our first translation.
2379 Initial support for debugging programs compiled with the GNAT
2380 implementation of the Ada programming language has been integrated
2381 into GDB. In this release, support is limited to expression evaluation.
2383 * New native configurations
2385 GNU/Linux/m32r m32r-*-linux-gnu
2389 GDB's remote protocol now includes support for the 'p' packet. This
2390 packet is used to fetch individual registers from a remote inferior.
2392 * END-OF-LIFE registers[] compatibility module
2394 GDB's internal register infrastructure has been completely rewritten.
2395 The new infrastructure making possible the implementation of key new
2396 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2399 GDB 6.3 will be the last release to include the the registers[]
2400 compatibility module that allowed out-of-date configurations to
2401 continue to work. This change directly impacts the following
2411 powerpc bdm protocol
2413 Unless there is activity to revive these configurations, they will be
2414 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2416 * OBSOLETE configurations and files
2418 Configurations that have been declared obsolete in this release have
2419 been commented out. Unless there is activity to revive these
2420 configurations, the next release of GDB will have their sources
2421 permanently REMOVED.
2430 *** Changes in GDB 6.2.1:
2432 * MIPS `break main; run' gave an heuristic-fence-post warning
2434 When attempting to run even a simple program, a warning about
2435 heuristic-fence-post being hit would be reported. This problem has
2438 * MIPS IRIX 'long double' crashed GDB
2440 When examining a long double variable, GDB would get a segmentation
2441 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2442 IRIX long double values).
2446 A bug in the VAX stack code was causing problems with the "next"
2447 command. This problem has been fixed.
2449 *** Changes in GDB 6.2:
2451 * Fix for ``many threads''
2453 On GNU/Linux systems that use the NPTL threads library, a program
2454 rapidly creating and deleting threads would confuse GDB leading to the
2457 ptrace: No such process.
2458 thread_db_get_info: cannot get thread info: generic error
2460 This problem has been fixed.
2462 * "-async" and "-noasync" options removed.
2464 Support for the broken "-noasync" option has been removed (it caused
2467 * New ``start'' command.
2469 This command runs the program until the begining of the main procedure.
2471 * New BSD Kernel Data Access Library (libkvm) interface
2473 Using ``target kvm'' it is now possible to debug kernel core dumps and
2474 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2475 platforms. Currently supported (native-only) configurations are:
2477 FreeBSD/amd64 x86_64-*-freebsd*
2478 FreeBSD/i386 i?86-*-freebsd*
2479 NetBSD/i386 i?86-*-netbsd*
2480 NetBSD/m68k m68*-*-netbsd*
2481 NetBSD/sparc sparc-*-netbsd*
2482 OpenBSD/amd64 x86_64-*-openbsd*
2483 OpenBSD/i386 i?86-*-openbsd*
2484 OpenBSD/m68k m68*-openbsd*
2485 OpenBSD/sparc sparc-*-openbsd*
2487 * Signal trampoline code overhauled
2489 Many generic problems with GDB's signal handling code have been fixed.
2490 These include: backtraces through non-contiguous stacks; recognition
2491 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2492 call; backtrace through a signal trampoline; step into and out of
2493 signal handlers; and single-stepping in the signal trampoline.
2495 Please note that kernel bugs are a limiting factor here. These
2496 features have been shown to work on an s390 GNU/Linux system that
2497 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2499 * Cygwin support for DWARF 2 added.
2501 * New native configurations
2503 GNU/Linux/hppa hppa*-*-linux*
2504 OpenBSD/hppa hppa*-*-openbsd*
2505 OpenBSD/m68k m68*-*-openbsd*
2506 OpenBSD/m88k m88*-*-openbsd*
2507 OpenBSD/powerpc powerpc-*-openbsd*
2508 NetBSD/vax vax-*-netbsd*
2509 OpenBSD/vax vax-*-openbsd*
2511 * END-OF-LIFE frame compatibility module
2513 GDB's internal frame infrastructure has been completely rewritten.
2514 The new infrastructure making it possible to support key new features
2515 including DWARF 2 Call Frame Information. To aid in the task of
2516 migrating old configurations to this new infrastructure, a
2517 compatibility module, that allowed old configurations to continue to
2518 work, was also included.
2520 GDB 6.2 will be the last release to include this frame compatibility
2521 module. This change directly impacts the following configurations:
2531 Unless there is activity to revive these configurations, they will be
2532 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2534 * REMOVED configurations and files
2536 Sun 3, running SunOS 3 m68*-*-sunos3*
2537 Sun 3, running SunOS 4 m68*-*-sunos4*
2538 Sun 2, running SunOS 3 m68000-*-sunos3*
2539 Sun 2, running SunOS 4 m68000-*-sunos4*
2540 Motorola 680x0 running LynxOS m68*-*-lynxos*
2541 AT&T 3b1/Unix pc m68*-att-*
2542 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2543 decstation mips-dec-* mips-little-*
2544 riscos mips-*-riscos* mips-*-sysv*
2545 sonymips mips-sony-*
2546 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2548 *** Changes in GDB 6.1.1:
2550 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2552 The TUI (Text-mode User Interface) is now built as part of a default
2553 GDB configuration. It is enabled by either selecting the TUI with the
2554 command line option "-i=tui" or by running the separate "gdbtui"
2555 program. For more information on the TUI, see the manual "Debugging
2558 * Pending breakpoint support (also included in GDB 6.1)
2560 Support has been added to allow you to specify breakpoints in shared
2561 libraries that have not yet been loaded. If a breakpoint location
2562 cannot be found, and the "breakpoint pending" option is set to auto,
2563 GDB queries you if you wish to make the breakpoint pending on a future
2564 shared-library load. If and when GDB resolves the breakpoint symbol,
2565 the pending breakpoint is removed as one or more regular breakpoints
2568 Pending breakpoints are very useful for GCJ Java debugging.
2570 * Fixed ISO-C build problems
2572 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2573 non ISO-C code that stopped them being built using a more strict ISO-C
2574 compiler (e.g., IBM's C compiler).
2576 * Fixed build problem on IRIX 5
2578 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2579 wasn't able to compile compile on an IRIX 5 system.
2581 * Added execute permission to gdb/gdbserver/configure
2583 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2584 permission. This bug would cause configure to fail on a number of
2585 systems (Solaris, IRIX). Ref: server/519.
2587 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2589 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2590 has been updated to use constant array sizes.
2592 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2594 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2595 its generated DWARF Call Frame Info. This encoding was causing GDB to
2596 panic, that panic has been fixed. Ref: gdb/1628.
2598 * Fixed a problem when examining parameters in shared library code.
2600 When examining parameters in optimized shared library code generated
2601 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2602 not available''. GDB now correctly displays the variable's value.
2604 *** Changes in GDB 6.1:
2606 * Removed --with-mmalloc
2608 Support for the mmalloc memory manager has been removed, as it
2609 conflicted with the internal gdb byte cache.
2611 * Changes in AMD64 configurations
2613 The AMD64 target now includes the %cs and %ss registers. As a result
2614 the AMD64 remote protocol has changed; this affects the floating-point
2615 and SSE registers. If you rely on those registers for your debugging,
2616 you should upgrade gdbserver on the remote side.
2618 * Revised SPARC target
2620 The SPARC target has been completely revised, incorporating the
2621 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
2622 support for LynxOS and SunOS 4 has been dropped. Calling functions
2623 from within GDB on operating systems with a non-executable stack
2624 (Solaris, OpenBSD) now works.
2628 GDB has a new C++ demangler which does a better job on the mangled
2629 names generated by current versions of g++. It also runs faster, so
2630 with this and other changes gdb should now start faster on large C++
2633 * DWARF 2 Location Expressions
2635 GDB support for location expressions has been extended to support function
2636 arguments and frame bases. Older versions of GDB could crash when they
2639 * C++ nested types and namespaces
2641 GDB's support for nested types and namespaces in C++ has been
2642 improved, especially if you use the DWARF 2 debugging format. (This
2643 is the default for recent versions of GCC on most platforms.)
2644 Specifically, if you have a class "Inner" defined within a class or
2645 namespace "Outer", then GDB realizes that the class's name is
2646 "Outer::Inner", not simply "Inner". This should greatly reduce the
2647 frequency of complaints about not finding RTTI symbols. In addition,
2648 if you are stopped at inside of a function defined within a namespace,
2649 GDB modifies its name lookup accordingly.
2651 * New native configurations
2653 NetBSD/amd64 x86_64-*-netbsd*
2654 OpenBSD/amd64 x86_64-*-openbsd*
2655 OpenBSD/alpha alpha*-*-openbsd*
2656 OpenBSD/sparc sparc-*-openbsd*
2657 OpenBSD/sparc64 sparc64-*-openbsd*
2659 * New debugging protocols
2661 M32R with SDI protocol m32r-*-elf*
2663 * "set prompt-escape-char" command deleted.
2665 The command "set prompt-escape-char" has been deleted. This command,
2666 and its very obscure effet on GDB's prompt, was never documented,
2667 tested, nor mentioned in the NEWS file.
2669 * OBSOLETE configurations and files
2671 Configurations that have been declared obsolete in this release have
2672 been commented out. Unless there is activity to revive these
2673 configurations, the next release of GDB will have their sources
2674 permanently REMOVED.
2676 Sun 3, running SunOS 3 m68*-*-sunos3*
2677 Sun 3, running SunOS 4 m68*-*-sunos4*
2678 Sun 2, running SunOS 3 m68000-*-sunos3*
2679 Sun 2, running SunOS 4 m68000-*-sunos4*
2680 Motorola 680x0 running LynxOS m68*-*-lynxos*
2681 AT&T 3b1/Unix pc m68*-att-*
2682 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2683 decstation mips-dec-* mips-little-*
2684 riscos mips-*-riscos* mips-*-sysv*
2685 sonymips mips-sony-*
2686 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2688 * REMOVED configurations and files
2690 SGI Irix-4.x mips-sgi-irix4 or iris4
2691 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
2692 Z8000 simulator z8k-zilog-none or z8ksim
2693 Matsushita MN10200 w/simulator mn10200-*-*
2694 H8/500 simulator h8500-hitachi-hms or h8500hms
2695 HP/PA running BSD hppa*-*-bsd*
2696 HP/PA running OSF/1 hppa*-*-osf*
2697 HP/PA Pro target hppa*-*-pro*
2698 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2699 386BSD i[3456]86-*-bsd*
2700 Sequent family i[3456]86-sequent-sysv4*
2701 i[3456]86-sequent-sysv*
2702 i[3456]86-sequent-bsd*
2703 SPARC running LynxOS sparc-*-lynxos*
2704 SPARC running SunOS 4 sparc-*-sunos4*
2705 Tsqware Sparclet sparclet-*-*
2706 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2708 *** Changes in GDB 6.0:
2712 Support for debugging the Objective-C programming language has been
2713 integrated into GDB.
2715 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
2717 DWARF 2's Call Frame Information makes available compiler generated
2718 information that more exactly describes the program's run-time stack.
2719 By using this information, GDB is able to provide more robust stack
2722 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
2723 have been updated to use a new backtrace mechanism which includes
2724 DWARF 2 CFI support.
2728 GDB's remote protocol has been extended to include support for hosted
2729 file I/O (where the remote target uses GDB's file system). See GDB's
2730 remote protocol documentation for details.
2732 * All targets using the new architecture framework.
2734 All of GDB's targets have been updated to use the new internal
2735 architecture framework. The way is now open for future GDB releases
2736 to include cross-architecture native debugging support (i386 on amd64,
2739 * GNU/Linux's Thread Local Storage (TLS)
2741 GDB now includes support for for the GNU/Linux implementation of
2742 per-thread variables.
2744 * GNU/Linux's Native POSIX Thread Library (NPTL)
2746 GDB's thread code has been updated to work with either the new
2747 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
2749 * Separate debug info.
2751 GDB, in conjunction with BINUTILS, now supports a mechanism for
2752 automatically loading debug information from a separate file. Instead
2753 of shipping full debug and non-debug versions of system libraries,
2754 system integrators can now instead ship just the stripped libraries
2755 and optional debug files.
2757 * DWARF 2 Location Expressions
2759 DWARF 2 Location Expressions allow the compiler to more completely
2760 describe the location of variables (even in optimized code) to the
2763 GDB now includes preliminary support for location expressions (support
2764 for DW_OP_piece is still missing).
2768 A number of long standing bugs that caused GDB to die while starting a
2769 Java application have been fixed. GDB's Java support is now
2770 considered "useable".
2772 * GNU/Linux support for fork, vfork, and exec.
2774 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
2775 commands are now implemented for GNU/Linux. They require a 2.5.x or later
2778 * GDB supports logging output to a file
2780 There are two new commands, "set logging" and "show logging", which can be
2781 used to capture GDB's output to a file.
2783 * The meaning of "detach" has changed for gdbserver
2785 The "detach" command will now resume the application, as documented. To
2786 disconnect from gdbserver and leave it stopped, use the new "disconnect"
2789 * d10v, m68hc11 `regs' command deprecated
2791 The `info registers' command has been updated so that it displays the
2792 registers using a format identical to the old `regs' command.
2796 A new command, "maint set profile on/off", has been added. This command can
2797 be used to enable or disable profiling while running GDB, to profile a
2798 session or a set of commands. In addition there is a new configure switch,
2799 "--enable-profiling", which will cause GDB to be compiled with profiling
2800 data, for more informative profiling results.
2802 * Default MI syntax changed to "mi2".
2804 The default MI (machine interface) syntax, enabled by the command line
2805 option "-i=mi", has been changed to "mi2". The previous MI syntax,
2806 "mi1", can be enabled by specifying the option "-i=mi1".
2808 Support for the original "mi0" syntax (included in GDB 5.0) has been
2811 Fix for gdb/192: removed extraneous space when displaying frame level.
2812 Fix for gdb/672: update changelist is now output in mi list format.
2813 Fix for gdb/702: a -var-assign that updates the value now shows up
2814 in a subsequent -var-update.
2816 * New native configurations.
2818 FreeBSD/amd64 x86_64-*-freebsd*
2820 * Multi-arched targets.
2822 HP/PA HPUX11 hppa*-*-hpux*
2823 Renesas M32R/D w/simulator m32r-*-elf*
2825 * OBSOLETE configurations and files
2827 Configurations that have been declared obsolete in this release have
2828 been commented out. Unless there is activity to revive these
2829 configurations, the next release of GDB will have their sources
2830 permanently REMOVED.
2832 Z8000 simulator z8k-zilog-none or z8ksim
2833 Matsushita MN10200 w/simulator mn10200-*-*
2834 H8/500 simulator h8500-hitachi-hms or h8500hms
2835 HP/PA running BSD hppa*-*-bsd*
2836 HP/PA running OSF/1 hppa*-*-osf*
2837 HP/PA Pro target hppa*-*-pro*
2838 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
2839 Sequent family i[3456]86-sequent-sysv4*
2840 i[3456]86-sequent-sysv*
2841 i[3456]86-sequent-bsd*
2842 Tsqware Sparclet sparclet-*-*
2843 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
2845 * REMOVED configurations and files
2848 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2849 IBM AIX PS/2 i[3456]86-*-aix
2850 i386 running Mach 3.0 i[3456]86-*-mach3*
2851 i386 running Mach i[3456]86-*-mach*
2852 i386 running OSF/1 i[3456]86-*osf1mk*
2853 HP/Apollo 68k Family m68*-apollo*-sysv*,
2855 m68*-hp-bsd*, m68*-hp-hpux*
2856 Argonaut Risc Chip (ARC) arc-*-*
2857 Mitsubishi D30V d30v-*-*
2858 Fujitsu FR30 fr30-*-elf*
2859 OS/9000 i[34]86-*-os9k
2860 I960 with MON960 i960-*-coff
2862 * MIPS $fp behavior changed
2864 The convenience variable $fp, for the MIPS, now consistently returns
2865 the address of the current frame's base. Previously, depending on the
2866 context, $fp could refer to either $sp or the current frame's base
2867 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
2868 The GNU Source-Level Debugger''.
2870 *** Changes in GDB 5.3:
2872 * GNU/Linux shared library multi-threaded performance improved.
2874 When debugging a multi-threaded application on GNU/Linux, GDB now uses
2875 `/proc', in preference to `ptrace' for memory reads. This may result
2876 in an improvement in the start-up time of multi-threaded, shared
2877 library applications when run under GDB. One GDB user writes: ``loads
2878 shared libs like mad''.
2880 * ``gdbserver'' now supports multi-threaded applications on some targets
2882 Support for debugging multi-threaded applications which use
2883 the GNU/Linux LinuxThreads package has been added for
2884 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
2885 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
2887 * GDB now supports C/C++ preprocessor macros.
2889 GDB now expands preprocessor macro invocations in C/C++ expressions,
2890 and provides various commands for showing macro definitions and how
2893 The new command `macro expand EXPRESSION' expands any macro
2894 invocations in expression, and shows the result.
2896 The new command `show macro MACRO-NAME' shows the definition of the
2897 macro named MACRO-NAME, and where it was defined.
2899 Most compilers don't include information about macros in the debugging
2900 information by default. In GCC 3.1, for example, you need to compile
2901 your program with the options `-gdwarf-2 -g3'. If the macro
2902 information is present in the executable, GDB will read it.
2904 * Multi-arched targets.
2906 DEC Alpha (partial) alpha*-*-*
2907 DEC VAX (partial) vax-*-*
2909 National Semiconductor NS32000 (partial) ns32k-*-*
2910 Motorola 68000 (partial) m68k-*-*
2911 Motorola MCORE mcore-*-*
2915 Fujitsu FRV architecture added by Red Hat frv*-*-*
2918 * New native configurations
2920 Alpha NetBSD alpha*-*-netbsd*
2921 SH NetBSD sh*-*-netbsdelf*
2922 MIPS NetBSD mips*-*-netbsd*
2923 UltraSPARC NetBSD sparc64-*-netbsd*
2925 * OBSOLETE configurations and files
2927 Configurations that have been declared obsolete in this release have
2928 been commented out. Unless there is activity to revive these
2929 configurations, the next release of GDB will have their sources
2930 permanently REMOVED.
2932 Mitsubishi D30V d30v-*-*
2933 OS/9000 i[34]86-*-os9k
2934 IBM AIX PS/2 i[3456]86-*-aix
2935 Fujitsu FR30 fr30-*-elf*
2936 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
2937 Argonaut Risc Chip (ARC) arc-*-*
2938 i386 running Mach 3.0 i[3456]86-*-mach3*
2939 i386 running Mach i[3456]86-*-mach*
2940 i386 running OSF/1 i[3456]86-*osf1mk*
2941 HP/Apollo 68k Family m68*-apollo*-sysv*,
2943 m68*-hp-bsd*, m68*-hp-hpux*
2944 I960 with MON960 i960-*-coff
2946 * OBSOLETE languages
2948 CHILL, a Pascal like language used by telecommunications companies.
2950 * REMOVED configurations and files
2952 AMD 29k family via UDI a29k-amd-udi, udi29k
2953 A29K VxWorks a29k-*-vxworks
2954 AMD 29000 embedded, using EBMON a29k-none-none
2955 AMD 29000 embedded with COFF a29k-none-coff
2956 AMD 29000 embedded with a.out a29k-none-aout
2958 testsuite/gdb.hp/gdb.threads-hp/ directory
2960 * New command "set max-user-call-depth <nnn>"
2962 This command allows the user to limit the call depth of user-defined
2963 commands. The default is 1024.
2965 * Changes in FreeBSD/i386 native debugging.
2967 Support for the "generate-core-file" has been added.
2969 * New commands "dump", "append", and "restore".
2971 These commands allow data to be copied from target memory
2972 to a bfd-format or binary file (dump and append), and back
2973 from a file into memory (restore).
2975 * Improved "next/step" support on multi-processor Alpha Tru64.
2977 The previous single-step mechanism could cause unpredictable problems,
2978 including the random appearance of SIGSEGV or SIGTRAP signals. The use
2979 of a software single-step mechanism prevents this.
2981 *** Changes in GDB 5.2.1:
2989 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
2990 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
2991 Fix, by Joel Brobecker imported from mainline.
2993 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
2994 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
2995 Fix, by Fred Fish, imported from mainline.
2997 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
2998 Surprisingly enough, it works now.
2999 By Michal Ludvig, imported from mainline.
3001 i386 hardware watchpoint support:
3002 avoid misses on second run for some targets.
3003 By Pierre Muller, imported from mainline.
3005 *** Changes in GDB 5.2:
3007 * New command "set trust-readonly-sections on[off]".
3009 This command is a hint that tells gdb that read-only sections
3010 really are read-only (ie. that their contents will not change).
3011 In this mode, gdb will go to the object file rather than the
3012 target to read memory from read-only sections (such as ".text").
3013 This can be a significant performance improvement on some
3014 (notably embedded) targets.
3016 * New command "generate-core-file" (or "gcore").
3018 This new gdb command allows the user to drop a core file of the child
3019 process state at any time. So far it's been implemented only for
3020 GNU/Linux and Solaris, but should be relatively easily ported to other
3021 hosts. Argument is core file name (defaults to core.<pid>).
3023 * New command line option
3025 GDB now accepts --pid or -p followed by a process id.
3027 * Change in command line behavior -- corefiles vs. process ids.
3029 There is a subtle behavior in the way in which GDB handles
3030 command line arguments. The first non-flag argument is always
3031 a program to debug, but the second non-flag argument may either
3032 be a corefile or a process id. Previously, GDB would attempt to
3033 open the second argument as a corefile, and if that failed, would
3034 issue a superfluous error message and then attempt to attach it as
3035 a process. Now, if the second argument begins with a non-digit,
3036 it will be treated as a corefile. If it begins with a digit,
3037 GDB will attempt to attach it as a process, and if no such process
3038 is found, will then attempt to open it as a corefile.
3040 * Changes in ARM configurations.
3042 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3043 configuration is fully multi-arch.
3045 * New native configurations
3047 ARM NetBSD arm*-*-netbsd*
3048 x86 OpenBSD i[3456]86-*-openbsd*
3049 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3050 Sparc64 running FreeBSD sparc64-*-freebsd*
3054 Sanyo XStormy16 xstormy16-elf
3056 * OBSOLETE configurations and files
3058 Configurations that have been declared obsolete in this release have
3059 been commented out. Unless there is activity to revive these
3060 configurations, the next release of GDB will have their sources
3061 permanently REMOVED.
3063 AMD 29k family via UDI a29k-amd-udi, udi29k
3064 A29K VxWorks a29k-*-vxworks
3065 AMD 29000 embedded, using EBMON a29k-none-none
3066 AMD 29000 embedded with COFF a29k-none-coff
3067 AMD 29000 embedded with a.out a29k-none-aout
3069 testsuite/gdb.hp/gdb.threads-hp/ directory
3071 * REMOVED configurations and files
3073 TI TMS320C80 tic80-*-*
3075 PowerPC Solaris powerpcle-*-solaris*
3076 PowerPC Windows NT powerpcle-*-cygwin32
3077 PowerPC Netware powerpc-*-netware*
3078 Harris/CXUX m88k m88*-harris-cxux*
3079 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3080 ns32k-utek-sysv* ns32k-utek-*
3081 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3082 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3083 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3084 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3085 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3087 * Changes to command line processing
3089 The new `--args' feature can be used to specify command-line arguments
3090 for the inferior from gdb's command line.
3092 * Changes to key bindings
3094 There is a new `operate-and-get-next' function bound to `C-o'.
3096 *** Changes in GDB 5.1.1
3098 Fix compile problem on DJGPP.
3100 Fix a problem with floating-point registers on the i386 being
3103 Fix to stop GDB crashing on .debug_str debug info.
3105 Numerous documentation fixes.
3107 Numerous testsuite fixes.
3109 *** Changes in GDB 5.1:
3111 * New native configurations
3113 Alpha FreeBSD alpha*-*-freebsd*
3114 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3115 MIPS GNU/Linux mips*-*-linux*
3116 MIPS SGI Irix 6.x mips*-sgi-irix6*
3117 ia64 AIX ia64-*-aix*
3118 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3122 Motorola 68HC11 and 68HC12 m68hc11-elf
3124 UltraSparc running GNU/Linux sparc64-*-linux*
3126 * OBSOLETE configurations and files
3128 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3129 Harris/CXUX m88k m88*-harris-cxux*
3130 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3131 ns32k-utek-sysv* ns32k-utek-*
3132 TI TMS320C80 tic80-*-*
3134 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3135 PowerPC Solaris powerpcle-*-solaris*
3136 PowerPC Windows NT powerpcle-*-cygwin32
3137 PowerPC Netware powerpc-*-netware*
3138 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3139 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3140 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3141 Apple Macintosh (MPW) host N/A
3143 stuff.c (Program to stuff files into a specially prepared space in kdb)
3144 kdb-start.c (Main loop for the standalone kernel debugger)
3146 Configurations that have been declared obsolete in this release have
3147 been commented out. Unless there is activity to revive these
3148 configurations, the next release of GDB will have their sources
3149 permanently REMOVED.
3151 * REMOVED configurations and files
3153 Altos 3068 m68*-altos-*
3154 Convex c1-*-*, c2-*-*
3156 ARM RISCix arm-*-* (as host)
3160 * GDB has been converted to ISO C.
3162 GDB's source code has been converted to ISO C. In particular, the
3163 sources are fully protoized, and rely on standard headers being
3168 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3170 * The MI enabled by default.
3172 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3173 revised and enabled by default. Packages which use GDB as a debugging
3174 engine behind a UI or another front end are encouraged to switch to
3175 using the GDB/MI interface, instead of the old annotations interface
3176 which is now deprecated.
3178 * Support for debugging Pascal programs.
3180 GDB now includes support for debugging Pascal programs. The following
3181 main features are supported:
3183 - Pascal-specific data types such as sets;
3185 - automatic recognition of Pascal sources based on file-name
3188 - Pascal-style display of data types, variables, and functions;
3190 - a Pascal expression parser.
3192 However, some important features are not yet supported.
3194 - Pascal string operations are not supported at all;
3196 - there are some problems with boolean types;
3198 - Pascal type hexadecimal constants are not supported
3199 because they conflict with the internal variables format;
3201 - support for Pascal objects and classes is not full yet;
3203 - unlike Pascal, GDB is case-sensitive for symbol names.
3205 * Changes in completion.
3207 Commands such as `shell', `run' and `set args', which pass arguments
3208 to inferior programs, now complete on file names, similar to what
3209 users expect at the shell prompt.
3211 Commands which accept locations, such as `disassemble', `print',
3212 `breakpoint', `until', etc. now complete on filenames as well as
3213 program symbols. Thus, if you type "break foob TAB", and the source
3214 files linked into the programs include `foobar.c', that file name will
3215 be one of the candidates for completion. However, file names are not
3216 considered for completion after you typed a colon that delimits a file
3217 name from a name of a function in that file, as in "break foo.c:bar".
3219 `set demangle-style' completes on available demangling styles.
3221 * New platform-independent commands:
3223 It is now possible to define a post-hook for a command as well as a
3224 hook that runs before the command. For more details, see the
3225 documentation of `hookpost' in the GDB manual.
3227 * Changes in GNU/Linux native debugging.
3229 Support for debugging multi-threaded programs has been completely
3230 revised for all platforms except m68k and sparc. You can now debug as
3231 many threads as your system allows you to have.
3233 Attach/detach is supported for multi-threaded programs.
3235 Support for SSE registers was added for x86. This doesn't work for
3236 multi-threaded programs though.
3238 * Changes in MIPS configurations.
3240 Multi-arch support is enabled for all MIPS configurations.
3242 GDB can now be built as native debugger on SGI Irix 6.x systems for
3243 debugging n32 executables. (Debugging 64-bit executables is not yet
3246 * Unified support for hardware watchpoints in all x86 configurations.
3248 Most (if not all) native x86 configurations support hardware-assisted
3249 breakpoints and watchpoints in a unified manner. This support
3250 implements debug register sharing between watchpoints, which allows to
3251 put a virtually infinite number of watchpoints on the same address,
3252 and also supports watching regions up to 16 bytes with several debug
3255 The new maintenance command `maintenance show-debug-regs' toggles
3256 debugging print-outs in functions that insert, remove, and test
3257 watchpoints and hardware breakpoints.
3259 * Changes in the DJGPP native configuration.
3261 New command ``info dos sysinfo'' displays assorted information about
3262 the CPU, OS, memory, and DPMI server.
3264 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3265 display information about segment descriptors stored in GDT, LDT, and
3268 New commands ``info dos pde'' and ``info dos pte'' display entries
3269 from Page Directory and Page Tables (for now works with CWSDPMI only).
3270 New command ``info dos address-pte'' displays the Page Table entry for
3271 a given linear address.
3273 GDB can now pass command lines longer than 126 characters to the
3274 program being debugged (requires an update to the libdbg.a library
3275 which is part of the DJGPP development kit).
3277 DWARF2 debug info is now supported.
3279 It is now possible to `step' and `next' through calls to `longjmp'.
3281 * Changes in documentation.
3283 All GDB documentation was converted to GFDL, the GNU Free
3284 Documentation License.
3286 Tracepoints-related commands are now fully documented in the GDB
3289 TUI, the Text-mode User Interface, is now documented in the manual.
3291 Tracepoints-related commands are now fully documented in the GDB
3294 The "GDB Internals" manual now has an index. It also includes
3295 documentation of `ui_out' functions, GDB coding standards, x86
3296 hardware watchpoints, and memory region attributes.
3298 * GDB's version number moved to ``version.in''
3300 The Makefile variable VERSION has been replaced by the file
3301 ``version.in''. People creating GDB distributions should update the
3302 contents of this file.
3306 GUD support is now a standard part of the EMACS distribution.
3308 *** Changes in GDB 5.0:
3310 * Improved support for debugging FP programs on x86 targets
3312 Unified and much-improved support for debugging floating-point
3313 programs on all x86 targets. In particular, ``info float'' now
3314 displays the FP registers in the same format on all x86 targets, with
3315 greater level of detail.
3317 * Improvements and bugfixes in hardware-assisted watchpoints
3319 It is now possible to watch array elements, struct members, and
3320 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3321 on x86 targets no longer erroneously trigger when the address is
3324 * Improvements in the native DJGPP version of GDB
3326 The distribution now includes all the scripts and auxiliary files
3327 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3328 machines ``out of the box''.
3330 The DJGPP version can now debug programs that use signals. It is
3331 possible to catch signals that happened in the debuggee, deliver
3332 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3333 would kill the program being debugged.) Programs that hook hardware
3334 interrupts (keyboard, timer, etc.) can also be debugged.
3336 It is now possible to debug DJGPP programs that redirect their
3337 standard handles or switch them to raw (as opposed to cooked) mode, or
3338 even close them. The command ``run < foo > bar'' works as expected,
3339 and ``info terminal'' reports useful information about the debuggee's
3340 terminal, including raw/cooked mode, redirection, etc.
3342 The DJGPP version now uses termios functions for console I/O, which
3343 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3346 DOS-style file names with drive letters are now fully supported by
3349 It is now possible to debug DJGPP programs that switch their working
3350 directory. It is also possible to rerun the debuggee any number of
3351 times without restarting GDB; thus, you can use the same setup,
3352 breakpoints, etc. for many debugging sessions.
3354 * New native configurations
3356 ARM GNU/Linux arm*-*-linux*
3357 PowerPC GNU/Linux powerpc-*-linux*
3361 Motorola MCore mcore-*-*
3362 x86 VxWorks i[3456]86-*-vxworks*
3363 PowerPC VxWorks powerpc-*-vxworks*
3364 TI TMS320C80 tic80-*-*
3366 * OBSOLETE configurations
3368 Altos 3068 m68*-altos-*
3369 Convex c1-*-*, c2-*-*
3371 ARM RISCix arm-*-* (as host)
3374 Configurations that have been declared obsolete will be commented out,
3375 but the code will be left in place. If there is no activity to revive
3376 these configurations before the next release of GDB, the sources will
3377 be permanently REMOVED.
3379 * Gould support removed
3381 Support for the Gould PowerNode and NP1 has been removed.
3383 * New features for SVR4
3385 On SVR4 native platforms (such as Solaris), if you attach to a process
3386 without first loading a symbol file, GDB will now attempt to locate and
3387 load symbols from the running process's executable file.
3389 * Many C++ enhancements
3391 C++ support has been greatly improved. Overload resolution now works properly
3392 in almost all cases. RTTI support is on the way.
3394 * Remote targets can connect to a sub-program
3396 A popen(3) style serial-device has been added. This device starts a
3397 sub-process (such as a stand-alone simulator) and then communicates
3398 with that. The sub-program to run is specified using the syntax
3399 ``|<program> <args>'' vis:
3401 (gdb) set remotedebug 1
3402 (gdb) target extended-remote |mn10300-elf-sim program-args
3404 * MIPS 64 remote protocol
3406 A long standing bug in the mips64 remote protocol where by GDB
3407 expected certain 32 bit registers (ex SR) to be transfered as 32
3408 instead of 64 bits has been fixed.
3410 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3411 added to provide backward compatibility with older versions of GDB.
3413 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3415 The command ``set remotebinarydownload'' command has been replaced by
3416 ``set remote X-packet''. Other commands in ``set remote'' family
3417 include ``set remote P-packet''.
3419 * Breakpoint commands accept ranges.
3421 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3422 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3423 ``tracepoint passcount'' also accepts a range of tracepoints.
3425 * ``apropos'' command added.
3427 The ``apropos'' command searches through command names and
3428 documentation strings, printing out matches, making it much easier to
3429 try to find a command that does what you are looking for.
3433 A new machine oriented interface (MI) has been added to GDB. This
3434 interface is designed for debug environments running GDB as a separate
3435 process. This is part of the long term libGDB project. See the
3436 "GDB/MI" chapter of the GDB manual for further information. It can be
3437 enabled by configuring with:
3439 .../configure --enable-gdbmi
3441 *** Changes in GDB-4.18:
3443 * New native configurations
3445 HP-UX 10.20 hppa*-*-hpux10.20
3446 HP-UX 11.x hppa*-*-hpux11.0*
3447 M68K GNU/Linux m68*-*-linux*
3451 Fujitsu FR30 fr30-*-elf*
3452 Intel StrongARM strongarm-*-*
3453 Mitsubishi D30V d30v-*-*
3455 * OBSOLETE configurations
3457 Gould PowerNode, NP1 np1-*-*, pn-*-*
3459 Configurations that have been declared obsolete will be commented out,
3460 but the code will be left in place. If there is no activity to revive
3461 these configurations before the next release of GDB, the sources will
3462 be permanently REMOVED.
3466 As a compatibility experiment, GDB's source files buildsym.h and
3467 buildsym.c have been converted to pure standard C, no longer
3468 containing any K&R compatibility code. We believe that all systems in
3469 use today either come with a standard C compiler, or have a GCC port
3470 available. If this is not true, please report the affected
3471 configuration to bug-gdb@gnu.org immediately. See the README file for
3472 information about getting a standard C compiler if you don't have one
3477 GDB now uses readline 2.2.
3479 * set extension-language
3481 You can now control the mapping between filename extensions and source
3482 languages by using the `set extension-language' command. For instance,
3483 you can ask GDB to treat .c files as C++ by saying
3484 set extension-language .c c++
3485 The command `info extensions' lists all of the recognized extensions
3486 and their associated languages.
3488 * Setting processor type for PowerPC and RS/6000
3490 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3491 you can use the `set processor' command to specify what variant of the
3492 PowerPC family you are debugging. The command
3496 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3497 following PowerPC and RS6000 variants:
3499 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3500 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3502 403GC IBM PowerPC 403GC
3503 505 Motorola PowerPC 505
3504 860 Motorola PowerPC 860 or 850
3505 601 Motorola PowerPC 601
3506 602 Motorola PowerPC 602
3507 603 Motorola/IBM PowerPC 603 or 603e
3508 604 Motorola PowerPC 604 or 604e
3509 750 Motorola/IBM PowerPC 750 or 750
3511 At the moment, this command just tells GDB what to name the
3512 special-purpose processor registers. Since almost all the affected
3513 registers are inaccessible to user-level programs, this command is
3514 only useful for remote debugging in its present form.
3518 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3519 more extensive support for HP-UX. Added features include shared
3520 library support, kernel threads and hardware watchpoints for 11.00,
3521 support for HP's ANSI C and C++ compilers, and a compatibility mode
3522 for xdb and dbx commands.
3526 HP's donation includes the new concept of catchpoints, which is a
3527 generalization of the old catch command. On HP-UX, it is now possible
3528 to catch exec, fork, and vfork, as well as library loading.
3530 This means that the existing catch command has changed; its first
3531 argument now specifies the type of catch to be set up. See the
3532 output of "help catch" for a list of catchpoint types.
3534 * Debugging across forks
3536 On HP-UX, you can choose which process to debug when a fork() happens
3541 HP has donated a curses-based terminal user interface (TUI). To get
3542 it, build with --enable-tui. Although this can be enabled for any
3543 configuration, at present it only works for native HP debugging.
3545 * GDB remote protocol additions
3547 A new protocol packet 'X' that writes binary data is now available.
3548 Default behavior is to try 'X', then drop back to 'M' if the stub
3549 fails to respond. The settable variable `remotebinarydownload'
3550 allows explicit control over the use of 'X'.
3552 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3553 full 64-bit address. The command
3555 set remoteaddresssize 32
3557 can be used to revert to the old behaviour. For existing remote stubs
3558 the change should not be noticed, as the additional address information
3561 In order to assist in debugging stubs, you may use the maintenance
3562 command `packet' to send any text string to the stub. For instance,
3564 maint packet heythere
3566 sends the packet "$heythere#<checksum>". Note that it is very easy to
3567 disrupt a debugging session by sending the wrong packet at the wrong
3570 The compare-sections command allows you to compare section data on the
3571 target to what is in the executable file without uploading or
3572 downloading, by comparing CRC checksums.
3574 * Tracing can collect general expressions
3576 You may now collect general expressions at tracepoints. This requires
3577 further additions to the target-side stub; see tracepoint.c and
3578 doc/agentexpr.texi for further details.
3580 * mask-address variable for Mips
3582 For Mips targets, you may control the zeroing of the upper 32 bits of
3583 a 64-bit address by entering `set mask-address on'. This is mainly
3584 of interest to users of embedded R4xxx and R5xxx processors.
3586 * Higher serial baud rates
3588 GDB's serial code now allows you to specify baud rates 57600, 115200,
3589 230400, and 460800 baud. (Note that your host system may not be able
3590 to achieve all of these rates.)
3594 The i960 configuration now includes an initial implementation of a
3595 builtin simulator, contributed by Jim Wilson.
3598 *** Changes in GDB-4.17:
3600 * New native configurations
3602 Alpha GNU/Linux alpha*-*-linux*
3603 Unixware 2.x i[3456]86-unixware2*
3604 Irix 6.x mips*-sgi-irix6*
3605 PowerPC GNU/Linux powerpc-*-linux*
3606 PowerPC Solaris powerpcle-*-solaris*
3607 Sparc GNU/Linux sparc-*-linux*
3608 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3612 Argonaut Risc Chip (ARC) arc-*-*
3613 Hitachi H8/300S h8300*-*-*
3614 Matsushita MN10200 w/simulator mn10200-*-*
3615 Matsushita MN10300 w/simulator mn10300-*-*
3616 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
3617 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
3618 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
3619 Mitsubishi D10V w/simulator d10v-*-*
3620 Mitsubishi M32R/D w/simulator m32r-*-elf*
3621 Tsqware Sparclet sparclet-*-*
3622 NEC V850 w/simulator v850-*-*
3624 * New debugging protocols
3626 ARM with RDI protocol arm*-*-*
3627 M68K with dBUG monitor m68*-*-{aout,coff,elf}
3628 DDB and LSI variants of PMON protocol mips*-*-*
3629 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
3630 PowerPC with SDS protocol powerpc{,le}-*-eabi
3631 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
3635 All configurations can now understand and use the DWARF 2 debugging
3636 format. The choice is automatic, if the symbol file contains DWARF 2
3641 GDB now includes basic Java language support. This support is
3642 only useful with Java compilers that produce native machine code.
3644 * solib-absolute-prefix and solib-search-path
3646 For SunOS and SVR4 shared libraries, you may now set the prefix for
3647 loading absolute shared library symbol files, and the search path for
3648 locating non-absolute shared library symbol files.
3650 * Live range splitting
3652 GDB can now effectively debug code for which GCC has performed live
3653 range splitting as part of its optimization. See gdb/doc/LRS for
3654 more details on the expected format of the stabs information.
3658 GDB's support for the GNU Hurd, including thread debugging, has been
3659 updated to work with current versions of the Hurd.
3663 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
3664 instruction set. ARM GDB automatically detects when Thumb
3665 instructions are in use, and adjusts disassembly and backtracing
3670 GDB's MIPS target configurations now handle the MIP16 16-bit
3675 GDB now includes support for overlays; if an executable has been
3676 linked such that multiple sections are based at the same address, GDB
3677 will decide which section to use for symbolic info. You can choose to
3678 control the decision manually, using overlay commands, or implement
3679 additional target-side support and use "overlay load-target" to bring
3680 in the overlay mapping. Do "help overlay" for more detail.
3684 The command "info symbol <address>" displays information about
3685 the symbol at the specified address.
3689 The standard remote protocol now includes an extension that allows
3690 asynchronous collection and display of trace data. This requires
3691 extensive support in the target-side debugging stub. Tracing mode
3692 includes a new interaction mode in GDB and new commands: see the
3693 file tracepoint.c for more details.
3697 Configurations for embedded MIPS now include a simulator contributed
3698 by Cygnus Solutions. The simulator supports the instruction sets
3699 of most MIPS variants.
3703 Sparc configurations may now include the ERC32 simulator contributed
3704 by the European Space Agency. The simulator is not built into
3705 Sparc targets by default; configure with --enable-sim to include it.
3709 For target configurations that may include multiple variants of a
3710 basic architecture (such as MIPS and SH), you may now set the
3711 architecture explicitly. "set arch" sets, "info arch" lists
3712 the possible architectures.
3714 *** Changes in GDB-4.16:
3716 * New native configurations
3718 Windows 95, x86 Windows NT i[345]86-*-cygwin32
3719 M68K NetBSD m68k-*-netbsd*
3720 PowerPC AIX 4.x powerpc-*-aix*
3721 PowerPC MacOS powerpc-*-macos*
3722 PowerPC Windows NT powerpcle-*-cygwin32
3723 RS/6000 AIX 4.x rs6000-*-aix4*
3727 ARM with RDP protocol arm-*-*
3728 I960 with MON960 i960-*-coff
3729 MIPS VxWorks mips*-*-vxworks*
3730 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
3731 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
3733 Matra Sparclet sparclet-*-*
3737 The powerpc-eabi configuration now includes the PSIM simulator,
3738 contributed by Andrew Cagney, with assistance from Mike Meissner.
3739 PSIM is a very elaborate model of the PowerPC, including not only
3740 basic instruction set execution, but also details of execution unit
3741 performance and I/O hardware. See sim/ppc/README for more details.
3745 GDB now works with Solaris 2.5.
3747 * Windows 95/NT native
3749 GDB will now work as a native debugger on Windows 95 and Windows NT.
3750 To build it from source, you must use the "gnu-win32" environment,
3751 which uses a DLL to emulate enough of Unix to run the GNU tools.
3752 Further information, binaries, and sources are available at
3753 ftp.cygnus.com, under pub/gnu-win32.
3755 * dont-repeat command
3757 If a user-defined command includes the command `dont-repeat', then the
3758 command will not be repeated if the user just types return. This is
3759 useful if the command is time-consuming to run, so that accidental
3760 extra keystrokes don't run the same command many times.
3762 * Send break instead of ^C
3764 The standard remote protocol now includes an option to send a break
3765 rather than a ^C to the target in order to interrupt it. By default,
3766 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
3768 * Remote protocol timeout
3770 The standard remote protocol includes a new variable `remotetimeout'
3771 that allows you to set the number of seconds before GDB gives up trying
3772 to read from the target. The default value is 2.
3774 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
3776 By default GDB will automatically keep track of objects as they are
3777 loaded and unloaded by the dynamic linker. By using the command `set
3778 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
3779 when shared library events occur, thus allowing you to set breakpoints
3780 in shared libraries which are explicitly loaded by the inferior.
3782 Note this feature does not work on hpux8. On hpux9 you must link
3783 /usr/lib/end.o into your program. This feature should work
3784 automatically on hpux10.
3786 * Irix 5.x hardware watchpoint support
3788 Irix 5 configurations now support the use of hardware watchpoints.
3790 * Mips protocol "SYN garbage limit"
3792 When debugging a Mips target using the `target mips' protocol, you
3793 may set the number of characters that GDB will ignore by setting
3794 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
3795 every character. The default value is 1050.
3797 * Recording and replaying remote debug sessions
3799 If you set `remotelogfile' to the name of a file, gdb will write to it
3800 a recording of a remote debug session. This recording may then be
3801 replayed back to gdb using "gdbreplay". See gdbserver/README for
3802 details. This is useful when you have a problem with GDB while doing
3803 remote debugging; you can make a recording of the session and send it
3804 to someone else, who can then recreate the problem.
3806 * Speedups for remote debugging
3808 GDB includes speedups for downloading and stepping MIPS systems using
3809 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
3810 and more efficient S-record downloading.
3812 * Memory use reductions and statistics collection
3814 GDB now uses less memory and reports statistics about memory usage.
3815 Try the `maint print statistics' command, for example.
3817 *** Changes in GDB-4.15:
3819 * Psymtabs for XCOFF
3821 The symbol reader for AIX GDB now uses partial symbol tables. This
3822 can greatly improve startup time, especially for large executables.
3824 * Remote targets use caching
3826 Remote targets now use a data cache to speed up communication with the
3827 remote side. The data cache could lead to incorrect results because
3828 it doesn't know about volatile variables, thus making it impossible to
3829 debug targets which use memory mapped I/O devices. `set remotecache
3830 off' turns the the data cache off.
3832 * Remote targets may have threads
3834 The standard remote protocol now includes support for multiple threads
3835 in the target system, using new protocol commands 'H' and 'T'. See
3836 gdb/remote.c for details.
3840 If GDB is configured with `--enable-netrom', then it will include
3841 support for the NetROM ROM emulator from XLNT Designs. The NetROM
3842 acts as though it is a bank of ROM on the target board, but you can
3843 write into it over the network. GDB's support consists only of
3844 support for fast loading into the emulated ROM; to debug, you must use
3845 another protocol, such as standard remote protocol. The usual
3846 sequence is something like
3848 target nrom <netrom-hostname>
3850 target remote <netrom-hostname>:1235
3854 GDB now includes support for the Apple Macintosh, as a host only. It
3855 may be run as either an MPW tool or as a standalone application, and
3856 it can debug through the serial port. All the usual GDB commands are
3857 available, but to the target command, you must supply "serial" as the
3858 device type instead of "/dev/ttyXX". See mpw-README in the main
3859 directory for more information on how to build. The MPW configuration
3860 scripts */mpw-config.in support only a few targets, and only the
3861 mips-idt-ecoff target has been tested.
3865 GDB configuration now uses autoconf. This is not user-visible,
3866 but does simplify configuration and building.
3870 GDB now supports hpux10.
3872 *** Changes in GDB-4.14:
3874 * New native configurations
3876 x86 FreeBSD i[345]86-*-freebsd
3877 x86 NetBSD i[345]86-*-netbsd
3878 NS32k NetBSD ns32k-*-netbsd
3879 Sparc NetBSD sparc-*-netbsd
3883 A29K VxWorks a29k-*-vxworks
3884 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
3885 CPU32 EST-300 emulator m68*-*-est*
3886 PowerPC ELF powerpc-*-elf
3889 * Alpha OSF/1 support for procfs
3891 GDB now supports procfs under OSF/1-2.x and higher, which makes it
3892 possible to attach to running processes. As the mounting of the /proc
3893 filesystem is optional on the Alpha, GDB automatically determines
3894 the availability of /proc during startup. This can lead to problems
3895 if /proc is unmounted after GDB has been started.
3897 * Arguments to user-defined commands
3899 User commands may accept up to 10 arguments separated by whitespace.
3900 Arguments are accessed within the user command via $arg0..$arg9. A
3903 print $arg0 + $arg1 + $arg2
3905 To execute the command use:
3908 Defines the command "adder" which prints the sum of its three arguments.
3909 Note the arguments are text substitutions, so they may reference variables,
3910 use complex expressions, or even perform inferior function calls.
3912 * New `if' and `while' commands
3914 This makes it possible to write more sophisticated user-defined
3915 commands. Both commands take a single argument, which is the
3916 expression to evaluate, and must be followed by the commands to
3917 execute, one per line, if the expression is nonzero, the list being
3918 terminated by the word `end'. The `if' command list may include an
3919 `else' word, which causes the following commands to be executed only
3920 if the expression is zero.
3922 * Fortran source language mode
3924 GDB now includes partial support for Fortran 77. It will recognize
3925 Fortran programs and can evaluate a subset of Fortran expressions, but
3926 variables and functions may not be handled correctly. GDB will work
3927 with G77, but does not yet know much about symbols emitted by other
3930 * Better HPUX support
3932 Most debugging facilities now work on dynamic executables for HPPAs
3933 running hpux9 or later. You can attach to running dynamically linked
3934 processes, but by default the dynamic libraries will be read-only, so
3935 for instance you won't be able to put breakpoints in them. To change
3936 that behavior do the following before running the program:
3942 This will cause the libraries to be mapped private and read-write.
3943 To revert to the normal behavior, do this:
3949 You cannot set breakpoints or examine data in the library until after
3950 the library is loaded if the function/data symbols do not have
3953 GDB can now also read debug symbols produced by the HP C compiler on
3954 HPPAs (sorry, no C++, Fortran or 68k support).
3956 * Target byte order now dynamically selectable
3958 You can choose which byte order to use with a target system, via the
3959 commands "set endian big" and "set endian little", and you can see the
3960 current setting by using "show endian". You can also give the command
3961 "set endian auto", in which case GDB will use the byte order
3962 associated with the executable. Currently, only embedded MIPS
3963 configurations support dynamic selection of target byte order.
3965 * New DOS host serial code
3967 This version uses DPMI interrupts to handle buffered I/O, so you
3968 no longer need to run asynctsr when debugging boards connected to
3971 *** Changes in GDB-4.13:
3973 * New "complete" command
3975 This lists all the possible completions for the rest of the line, if it
3976 were to be given as a command itself. This is intended for use by emacs.
3978 * Trailing space optional in prompt
3980 "set prompt" no longer adds a space for you after the prompt you set. This
3981 allows you to set a prompt which ends in a space or one that does not.
3983 * Breakpoint hit counts
3985 "info break" now displays a count of the number of times the breakpoint
3986 has been hit. This is especially useful in conjunction with "ignore"; you
3987 can ignore a large number of breakpoint hits, look at the breakpoint info
3988 to see how many times the breakpoint was hit, then run again, ignoring one
3989 less than that number, and this will get you quickly to the last hit of
3992 * Ability to stop printing at NULL character
3994 "set print null-stop" will cause GDB to stop printing the characters of
3995 an array when the first NULL is encountered. This is useful when large
3996 arrays actually contain only short strings.
3998 * Shared library breakpoints
4000 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4001 breakpoints in shared libraries before the executable is run.
4003 * Hardware watchpoints
4005 There is a new hardware breakpoint for the watch command for sparclite
4006 targets. See gdb/sparclite/hw_breakpoint.note.
4008 Hardware watchpoints are also now supported under GNU/Linux.
4012 Annotations have been added. These are for use with graphical interfaces,
4013 and are still experimental. Currently only gdba.el uses these.
4015 * Improved Irix 5 support
4017 GDB now works properly with Irix 5.2.
4019 * Improved HPPA support
4021 GDB now works properly with the latest GCC and GAS.
4023 * New native configurations
4025 Sequent PTX4 i[34]86-sequent-ptx4
4026 HPPA running OSF/1 hppa*-*-osf*
4027 Atari TT running SVR4 m68*-*-sysv4*
4028 RS/6000 LynxOS rs6000-*-lynxos*
4032 OS/9000 i[34]86-*-os9k
4033 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4036 * Hitachi SH7000 and E7000-PC ICE support
4038 There is now support for communicating with the Hitachi E7000-PC ICE.
4039 This is available automatically when GDB is configured for the SH.
4043 As usual, a variety of small fixes and improvements, both generic
4044 and configuration-specific. See the ChangeLog for more detail.
4046 *** Changes in GDB-4.12:
4048 * Irix 5 is now supported
4052 GDB-4.12 on the HPPA has a number of changes which make it unable
4053 to debug the output from the currently released versions of GCC and
4054 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4055 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4056 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4059 *** Changes in GDB-4.11:
4061 * User visible changes:
4065 The "set remotedebug" option is now consistent between the mips remote
4066 target, remote targets using the gdb-specific protocol, UDI (AMD's
4067 debug protocol for the 29k) and the 88k bug monitor. It is now an
4068 integer specifying a debug level (normally 0 or 1, but 2 means more
4069 debugging info for the mips target).
4071 * DEC Alpha native support
4073 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4074 debug info, but GDB works fairly well with the DEC compiler and should
4075 work with a future GCC release. See the README file for a few
4076 Alpha-specific notes.
4078 * Preliminary thread implementation
4080 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4082 * LynxOS native and target support for 386
4084 This release has been hosted on LynxOS 2.2, and also can be configured
4085 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4088 * Improvements in C++ mangling/demangling.
4090 This release has much better g++ debugging, specifically in name
4091 mangling/demangling, virtual function calls, print virtual table,
4092 call methods, ...etc.
4094 *** Changes in GDB-4.10:
4096 * User visible changes:
4098 Remote debugging using the GDB-specific (`target remote') protocol now
4099 supports the `load' command. This is only useful if you have some
4100 other way of getting the stub to the target system, and you can put it
4101 somewhere in memory where it won't get clobbered by the download.
4103 Filename completion now works.
4105 When run under emacs mode, the "info line" command now causes the
4106 arrow to point to the line specified. Also, "info line" prints
4107 addresses in symbolic form (as well as hex).
4109 All vxworks based targets now support a user settable option, called
4110 vxworks-timeout. This option represents the number of seconds gdb
4111 should wait for responses to rpc's. You might want to use this if
4112 your vxworks target is, perhaps, a slow software simulator or happens
4113 to be on the far side of a thin network line.
4117 This release contains support for using a DEC alpha as a GDB host for
4118 cross debugging. Native alpha debugging is not supported yet.
4121 *** Changes in GDB-4.9:
4125 This is the first GDB release which is accompanied by a matching testsuite.
4126 The testsuite requires installation of dejagnu, which should be available
4127 via ftp from most sites that carry GNU software.
4131 'Cfront' style demangling has had its name changed to 'ARM' style, to
4132 emphasize that it was written from the specifications in the C++ Annotated
4133 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4134 disclaimers, it still generated too much confusion with users attempting to
4135 use gdb with AT&T cfront.
4139 GDB now uses a standard remote interface to a simulator library.
4140 So far, the library contains simulators for the Zilog Z8001/2, the
4141 Hitachi H8/300, H8/500 and Super-H.
4143 * New targets supported
4145 H8/300 simulator h8300-hitachi-hms or h8300hms
4146 H8/500 simulator h8500-hitachi-hms or h8500hms
4147 SH simulator sh-hitachi-hms or sh
4148 Z8000 simulator z8k-zilog-none or z8ksim
4149 IDT MIPS board over serial line mips-idt-ecoff
4151 Cross-debugging to GO32 targets is supported. It requires a custom
4152 version of the i386-stub.c module which is integrated with the
4153 GO32 memory extender.
4155 * New remote protocols
4157 MIPS remote debugging protocol.
4159 * New source languages supported
4161 This version includes preliminary support for Chill, a Pascal like language
4162 used by telecommunications companies. Chill support is also being integrated
4163 into the GNU compiler, but we don't know when it will be publically available.
4166 *** Changes in GDB-4.8:
4168 * HP Precision Architecture supported
4170 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4171 version of this support was available as a set of patches from the
4172 University of Utah. GDB does not support debugging of programs
4173 compiled with the HP compiler, because HP will not document their file
4174 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4175 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4177 Many problems in the preliminary version have been fixed.
4179 * Faster and better demangling
4181 We have improved template demangling and fixed numerous bugs in the GNU style
4182 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4183 character types (wchar_t) are now supported. Demangling of each symbol is now
4184 only done once, and is cached when the symbol table for a file is read in.
4185 This results in a small increase in memory usage for C programs, a moderate
4186 increase in memory usage for C++ programs, and a fantastic speedup in
4189 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4190 from the specifications in the Annotated Reference Manual, which AT&T's
4191 compiler does not actually implement.
4193 * G++ multiple inheritance compiler problem
4195 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4196 inheritance lattices was reworked to properly discover ambiguities. We
4197 recently found an example which causes this new algorithm to fail in a
4198 very subtle way, producing bad debug information for those classes.
4199 The file 'gcc.patch' (in this directory) can be applied to gcc to
4200 circumvent the problem. A future GCC release will contain a complete
4203 The previous G++ debug info problem (mentioned below for the gdb-4.7
4204 release) is fixed in gcc version 2.3.2.
4206 * Improved configure script
4208 The `configure' script will now attempt to guess your system type if
4209 you don't supply a host system type. The old scheme of supplying a
4210 host system triplet is preferable over using this. All the magic is
4211 done in the new `config.guess' script. Examine it for details.
4213 We have also brought our configure script much more in line with the FSF's
4214 version. It now supports the --with-xxx options. In particular,
4215 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4216 The resulting GDB will not be able to read arbitrary object file formats --
4217 only the format ``expected'' to be used on the configured target system.
4218 We hope to make this the default in a future release.
4220 * Documentation improvements
4222 There's new internal documentation on how to modify GDB, and how to
4223 produce clean changes to the code. We implore people to read it
4224 before submitting changes.
4226 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4227 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4228 `info' files are also provided. To build `info' files from scratch,
4229 you will need the latest `makeinfo' release, which will be available in
4230 a future texinfo-X.Y release.
4232 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4233 We're not sure exactly which versions have this problem, but it has
4234 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4235 or better. If that isn't possible, there is a patch in
4236 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4237 around this problem.
4241 GDB now supports array constants that can be used in expressions typed in by
4242 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4243 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4246 The new directory `gdb/sparclite' contains a program that demonstrates
4247 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4249 * New native hosts supported
4251 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4252 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4254 * New targets supported
4256 AMD 29k family via UDI a29k-amd-udi or udi29k
4258 * New file formats supported
4260 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4261 HPUX core files, and SCO 3.2v2 core files.
4265 Attaching to processes now works again; thanks for the many bug reports.
4267 We have also stomped on a bunch of core dumps caused by
4268 printf_filtered("%s") problems.
4270 We eliminated a copyright problem on the rpc and ptrace header files
4271 for VxWorks, which was discovered at the last minute during the 4.7
4272 release. You should now be able to build a VxWorks GDB.
4274 You can now interrupt gdb while an attached process is running. This
4275 will cause the attached process to stop, and give control back to GDB.
4277 We fixed problems caused by using too many file descriptors
4278 for reading symbols from object files and libraries. This was
4279 especially a problem for programs that used many (~100) shared
4282 The `step' command now only enters a subroutine if there is line number
4283 information for the subroutine. Otherwise it acts like the `next'
4284 command. Previously, `step' would enter subroutines if there was
4285 any debugging information about the routine. This avoids problems
4286 when using `cc -g1' on MIPS machines.
4288 * Internal improvements
4290 GDB's internal interfaces have been improved to make it easier to support
4291 debugging of multiple languages in the future.
4293 GDB now uses a common structure for symbol information internally.
4294 Minimal symbols (derived from linkage symbols in object files), partial
4295 symbols (from a quick scan of debug information), and full symbols
4296 contain a common subset of information, making it easier to write
4297 shared code that handles any of them.
4299 * New command line options
4301 We now accept --silent as an alias for --quiet.
4305 The memory-mapped-malloc library is now licensed under the GNU Library
4306 General Public License.
4308 *** Changes in GDB-4.7:
4310 * Host/native/target split
4312 GDB has had some major internal surgery to untangle the support for
4313 hosts and remote targets. Now, when you configure GDB for a remote
4314 target, it will no longer load in all of the support for debugging
4315 local programs on the host. When fully completed and tested, this will
4316 ensure that arbitrary host/target combinations are possible.
4318 The primary conceptual shift is to separate the non-portable code in
4319 GDB into three categories. Host specific code is required any time GDB
4320 is compiled on that host, regardless of the target. Target specific
4321 code relates to the peculiarities of the target, but can be compiled on
4322 any host. Native specific code is everything else: it can only be
4323 built when the host and target are the same system. Child process
4324 handling and core file support are two common `native' examples.
4326 GDB's use of /proc for controlling Unix child processes is now cleaner.
4327 It has been split out into a single module under the `target_ops' vector,
4328 plus two native-dependent functions for each system that uses /proc.
4330 * New hosts supported
4332 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4333 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4334 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4336 * New targets supported
4338 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4339 68030 and CPU32 m68030-*-*, m68332-*-*
4341 * New native hosts supported
4343 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4344 (386bsd is not well tested yet)
4345 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4347 * New file formats supported
4349 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4350 supports reading of `a.out.adobe' object files, which are an a.out
4351 format extended with minimal information about multiple sections.
4355 `show copying' is the same as the old `info copying'.
4356 `show warranty' is the same as `info warrantee'.
4357 These were renamed for consistency. The old commands continue to work.
4359 `info handle' is a new alias for `info signals'.
4361 You can now define pre-command hooks, which attach arbitrary command
4362 scripts to any command. The commands in the hook will be executed
4363 prior to the user's command. You can also create a hook which will be
4364 executed whenever the program stops. See gdb.texinfo.
4368 We now deal with Cfront style name mangling, and can even extract type
4369 info from mangled symbols. GDB can automatically figure out which
4370 symbol mangling style your C++ compiler uses.
4372 Calling of methods and virtual functions has been improved as well.
4376 The crash that occured when debugging Sun Ansi-C compiled binaries is
4377 fixed. This was due to mishandling of the extra N_SO stabs output
4380 We also finally got Ultrix 4.2 running in house, and fixed core file
4381 support, with help from a dozen people on the net.
4383 John M. Farrell discovered that the reason that single-stepping was so
4384 slow on all of the Mips based platforms (primarily SGI and DEC) was
4385 that we were trying to demangle and lookup a symbol used for internal
4386 purposes on every instruction that was being stepped through. Changing
4387 the name of that symbol so that it couldn't be mistaken for a C++
4388 mangled symbol sped things up a great deal.
4390 Rich Pixley sped up symbol lookups in general by getting much smarter
4391 about when C++ symbol mangling is necessary. This should make symbol
4392 completion (TAB on the command line) much faster. It's not as fast as
4393 we'd like, but it's significantly faster than gdb-4.6.
4397 A new user controllable variable 'call_scratch_address' can
4398 specify the location of a scratch area to be used when GDB
4399 calls a function in the target. This is necessary because the
4400 usual method of putting the scratch area on the stack does not work
4401 in systems that have separate instruction and data spaces.
4403 We integrated changes to support the 29k UDI (Universal Debugger
4404 Interface), but discovered at the last minute that we didn't have all
4405 of the appropriate copyright paperwork. We are working with AMD to
4406 resolve this, and hope to have it available soon.
4410 We have sped up the remote serial line protocol, especially for targets
4411 with lots of registers. It now supports a new `expedited status' ('T')
4412 message which can be used in place of the existing 'S' status message.
4413 This allows the remote stub to send only the registers that GDB
4414 needs to make a quick decision about single-stepping or conditional
4415 breakpoints, eliminating the need to fetch the entire register set for
4416 each instruction being stepped through.
4418 The GDB remote serial protocol now implements a write-through cache for
4419 registers, only re-reading the registers if the target has run.
4421 There is also a new remote serial stub for SPARC processors. You can
4422 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4423 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4424 processor with a serial port.
4428 Configure.in files have become much easier to read and modify. A new
4429 `table driven' format makes it more obvious what configurations are
4430 supported, and what files each one uses.
4434 There is a new opcodes library which will eventually contain all of the
4435 disassembly routines and opcode tables. At present, it only contains
4436 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4437 disassembler (binutils/objdump) to share these routines.
4439 The libiberty library is now copylefted under the GNU Library General
4440 Public License. This allows more liberal use, and was done so libg++
4441 can use it. This makes no difference to GDB, since the Library License
4442 grants all the rights from the General Public License.
4446 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4447 reference to the stabs symbol info used by the debugger. It is (as far
4448 as we know) the only published document on this fascinating topic. We
4449 encourage you to read it, compare it to the stabs information on your
4450 system, and send improvements on the document in general (to
4451 bug-gdb@prep.ai.mit.edu).
4453 And, of course, many bugs have been fixed.
4456 *** Changes in GDB-4.6:
4458 * Better support for C++ function names
4460 GDB now accepts as input the "demangled form" of C++ overloaded function
4461 names and member function names, and can do command completion on such names
4462 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4463 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4464 Make use of command completion, it is your friend.
4466 GDB also now accepts a variety of C++ mangled symbol formats. They are
4467 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4468 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4469 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4470 for the list of formats.
4472 * G++ symbol mangling problem
4474 Recent versions of gcc have a bug in how they emit debugging information for
4475 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4476 directory) can be applied to gcc to fix the problem. Alternatively, if you
4477 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4478 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4479 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4482 * New 'maintenance' command
4484 All of the commands related to hacking GDB internals have been moved out of
4485 the main command set, and now live behind the 'maintenance' command. This
4486 can also be abbreviated as 'mt'. The following changes were made:
4488 dump-me -> maintenance dump-me
4489 info all-breakpoints -> maintenance info breakpoints
4490 printmsyms -> maintenance print msyms
4491 printobjfiles -> maintenance print objfiles
4492 printpsyms -> maintenance print psymbols
4493 printsyms -> maintenance print symbols
4495 The following commands are new:
4497 maintenance demangle Call internal GDB demangler routine to
4498 demangle a C++ link name and prints the result.
4499 maintenance print type Print a type chain for a given symbol
4501 * Change to .gdbinit file processing
4503 We now read the $HOME/.gdbinit file before processing the argv arguments
4504 (e.g. reading symbol files or core files). This allows global parameters to
4505 be set, which will apply during the symbol reading. The ./.gdbinit is still
4506 read after argv processing.
4508 * New hosts supported
4510 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4512 GNU/Linux support i386-unknown-linux or linux
4514 We are also including code to support the HP/PA running BSD and HPUX. This
4515 is almost guaranteed not to work, as we didn't have time to test or build it
4516 for this release. We are including it so that the more adventurous (or
4517 masochistic) of you can play with it. We also had major problems with the
4518 fact that the compiler that we got from HP doesn't support the -g option.
4521 * New targets supported
4523 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4525 * More smarts about finding #include files
4527 GDB now remembers the compilation directory for all include files, and for
4528 all files from which C is generated (like yacc and lex sources). This
4529 greatly improves GDB's ability to find yacc/lex sources, and include files,
4530 especially if you are debugging your program from a directory different from
4531 the one that contains your sources.
4533 We also fixed a bug which caused difficulty with listing and setting
4534 breakpoints in include files which contain C code. (In the past, you had to
4535 try twice in order to list an include file that you hadn't looked at before.)
4537 * Interesting infernals change
4539 GDB now deals with arbitrary numbers of sections, where the symbols for each
4540 section must be relocated relative to that section's landing place in the
4541 target's address space. This work was needed to support ELF with embedded
4542 stabs used by Solaris-2.0.
4544 * Bug fixes (of course!)
4546 There have been loads of fixes for the following things:
4547 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4548 i960, stabs, DOS(GO32), procfs, etc...
4550 See the ChangeLog for details.
4552 *** Changes in GDB-4.5:
4554 * New machines supported (host and target)
4556 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4558 SGI Irix-4.x mips-sgi-irix4 or iris4
4560 * New malloc package
4562 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4563 Mmalloc is capable of handling mutiple heaps of memory. It is also
4564 capable of saving a heap to a file, and then mapping it back in later.
4565 This can be used to greatly speedup the startup of GDB by using a
4566 pre-parsed symbol table which lives in a mmalloc managed heap. For
4567 more details, please read mmalloc/mmalloc.texi.
4571 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4572 'help info proc' for details.
4574 * MIPS ecoff symbol table format
4576 The code that reads MIPS symbol table format is now supported on all hosts.
4577 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4580 * File name changes for MS-DOS
4582 Many files in the config directories have been renamed to make it easier to
4583 support GDB on MS-DOSe systems (which have very restrictive file name
4584 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4585 environment) is close to working but has some remaining problems. Note
4586 that debugging of DOS programs is not supported, due to limitations
4587 in the ``operating system'', but it can be used to host cross-debugging.
4589 * Cross byte order fixes
4591 Many fixes have been made to support cross debugging of Sparc and MIPS
4592 targets from hosts whose byte order differs.
4594 * New -mapped and -readnow options
4596 If memory-mapped files are available on your system through the 'mmap'
4597 system call, you can use the -mapped option on the `file' or
4598 `symbol-file' commands to cause GDB to write the symbols from your
4599 program into a reusable file. If the program you are debugging is
4600 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4601 Future GDB debugging sessions will notice the presence of this file,
4602 and will quickly map in symbol information from it, rather than reading
4603 the symbol table from the executable program. Using the '-mapped'
4604 option in a GDB `file' or `symbol-file' command has the same effect as
4605 starting GDB with the '-mapped' command-line option.
4607 You can cause GDB to read the entire symbol table immediately by using
4608 the '-readnow' option with any of the commands that load symbol table
4609 information (or on the GDB command line). This makes the command
4610 slower, but makes future operations faster.
4612 The -mapped and -readnow options are typically combined in order to
4613 build a `fred.syms' file that contains complete symbol information.
4614 A simple GDB invocation to do nothing but build a `.syms' file for future
4617 gdb -batch -nx -mapped -readnow programname
4619 The `.syms' file is specific to the host machine on which GDB is run.
4620 It holds an exact image of GDB's internal symbol table. It cannot be
4621 shared across multiple host platforms.
4623 * longjmp() handling
4625 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
4626 siglongjmp() without losing control. This feature has not yet been ported to
4627 all systems. It currently works on many 386 platforms, all MIPS-based
4628 platforms (SGI, DECstation, etc), and Sun3/4.
4632 Preliminary work has been put in to support the new Solaris OS from Sun. At
4633 this time, it can control and debug processes, but it is not capable of
4638 As always, many many bug fixes. The major areas were with g++, and mipsread.
4639 People using the MIPS-based platforms should experience fewer mysterious
4640 crashes and trashed symbol tables.
4642 *** Changes in GDB-4.4:
4644 * New machines supported (host and target)
4646 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4648 BSD Reno on Vax vax-dec-bsd
4649 Ultrix on Vax vax-dec-ultrix
4651 * New machines supported (target)
4653 AMD 29000 embedded, using EBMON a29k-none-none
4657 GDB continues to improve its handling of C++. `References' work better.
4658 The demangler has also been improved, and now deals with symbols mangled as
4659 per the Annotated C++ Reference Guide.
4661 GDB also now handles `stabs' symbol information embedded in MIPS
4662 `ecoff' symbol tables. Since the ecoff format was not easily
4663 extensible to handle new languages such as C++, this appeared to be a
4664 good way to put C++ debugging info into MIPS binaries. This option
4665 will be supported in the GNU C compiler, version 2, when it is
4668 * New features for SVR4
4670 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
4671 shared libraries. Debugging dynamically linked programs should present
4672 only minor differences from debugging statically linked programs.
4674 The `info proc' command will print out information about any process
4675 on an SVR4 system (including the one you are debugging). At the moment,
4676 it prints the address mappings of the process.
4678 If you bring up GDB on another SVR4 system, please send mail to
4679 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
4681 * Better dynamic linking support in SunOS
4683 Reading symbols from shared libraries which contain debugging symbols
4684 now works properly. However, there remain issues such as automatic
4685 skipping of `transfer vector' code during function calls, which
4686 make it harder to debug code in a shared library, than to debug the
4687 same code linked statically.
4691 GDB is now using the latest `getopt' routines from the FSF. This
4692 version accepts the -- prefix for options with long names. GDB will
4693 continue to accept the old forms (-option and +option) as well.
4694 Various single letter abbreviations for options have been explicity
4695 added to the option table so that they won't get overshadowed in the
4696 future by other options that begin with the same letter.
4700 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
4701 Many assorted bugs have been handled. Many more remain to be handled.
4702 See the various ChangeLog files (primarily in gdb and bfd) for details.
4705 *** Changes in GDB-4.3:
4707 * New machines supported (host and target)
4709 Amiga 3000 running Amix m68k-cbm-svr4 or amix
4710 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
4711 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4713 * Almost SCO Unix support
4715 We had hoped to support:
4716 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
4717 (except for core file support), but we discovered very late in the release
4718 that it has problems with process groups that render gdb unusable. Sorry
4719 about that. I encourage people to fix it and post the fixes.
4721 * Preliminary ELF and DWARF support
4723 GDB can read ELF object files on System V Release 4, and can handle
4724 debugging records for C, in DWARF format, in ELF files. This support
4725 is preliminary. If you bring up GDB on another SVR4 system, please
4726 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
4731 GDB now uses the latest `readline' library. One user-visible change
4732 is that two tabs will list possible command completions, which previously
4733 required typing M-? (meta-question mark, or ESC ?).
4737 The `stepi' bug that many of you noticed has been squashed.
4738 Many bugs in C++ have been handled. Many more remain to be handled.
4739 See the various ChangeLog files (primarily in gdb and bfd) for details.
4741 * State of the MIPS world (in case you wondered):
4743 GDB can understand the symbol tables emitted by the compilers
4744 supplied by most vendors of MIPS-based machines, including DEC. These
4745 symbol tables are in a format that essentially nobody else uses.
4747 Some versions of gcc come with an assembler post-processor called
4748 mips-tfile. This program is required if you want to do source-level
4749 debugging of gcc-compiled programs. I believe FSF does not ship
4750 mips-tfile with gcc version 1, but it will eventually come with gcc
4753 Debugging of g++ output remains a problem. g++ version 1.xx does not
4754 really support it at all. (If you're lucky, you should be able to get
4755 line numbers and stack traces to work, but no parameters or local
4756 variables.) With some work it should be possible to improve the
4759 When gcc version 2 is released, you will have somewhat better luck.
4760 However, even then you will get confusing results for inheritance and
4763 We will eventually provide full debugging of g++ output on
4764 DECstations. This will probably involve some kind of stabs-in-ecoff
4765 encapulation, but the details have not been worked out yet.
4768 *** Changes in GDB-4.2:
4770 * Improved configuration
4772 Only one copy of `configure' exists now, and it is not self-modifying.
4773 Porting BFD is simpler.
4777 The `step' and `next' commands now only stop at the first instruction
4778 of a source line. This prevents the multiple stops that used to occur
4779 in switch statements, for-loops, etc. `Step' continues to stop if a
4780 function that has debugging information is called within the line.
4784 Lots of small bugs fixed. More remain.
4786 * New host supported (not target)
4788 Intel 386 PC clone running Mach i386-none-mach
4791 *** Changes in GDB-4.1:
4793 * Multiple source language support
4795 GDB now has internal scaffolding to handle several source languages.
4796 It determines the type of each source file from its filename extension,
4797 and will switch expression parsing and number formatting to match the
4798 language of the function in the currently selected stack frame.
4799 You can also specifically set the language to be used, with
4800 `set language c' or `set language modula-2'.
4804 GDB now has preliminary support for the GNU Modula-2 compiler,
4805 currently under development at the State University of New York at
4806 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
4807 continue through the fall of 1991 and into 1992.
4809 Other Modula-2 compilers are currently not supported, and attempting to
4810 debug programs compiled with them will likely result in an error as the
4811 symbol table is read. Feel free to work on it, though!
4813 There are hooks in GDB for strict type checking and range checking,
4814 in the `Modula-2 philosophy', but they do not currently work.
4818 GDB can now write to executable and core files (e.g. patch
4819 a variable's value). You must turn this switch on, specify
4820 the file ("exec foo" or "core foo"), *then* modify it, e.g.
4821 by assigning a new value to a variable. Modifications take
4824 * Automatic SunOS shared library reading
4826 When you run your program, GDB automatically determines where its
4827 shared libraries (if any) have been loaded, and reads their symbols.
4828 The `share' command is no longer needed. This also works when
4829 examining core files.
4833 You can specify the number of lines that the `list' command shows.
4836 * New machines supported (host and target)
4838 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4839 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
4840 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
4842 * New hosts supported (not targets)
4844 IBM RT/PC: romp-ibm-aix or rtpc
4846 * New targets supported (not hosts)
4848 AMD 29000 embedded with COFF a29k-none-coff
4849 AMD 29000 embedded with a.out a29k-none-aout
4850 Ultracomputer remote kernel debug a29k-nyu-kern
4852 * New remote interfaces
4858 *** Changes in GDB-4.0:
4862 Wide output is wrapped at good places to make the output more readable.
4864 Gdb now supports cross-debugging from a host machine of one type to a
4865 target machine of another type. Communication with the target system
4866 is over serial lines. The ``target'' command handles connecting to the
4867 remote system; the ``load'' command will download a program into the
4868 remote system. Serial stubs for the m68k and i386 are provided. Gdb
4869 also supports debugging of realtime processes running under VxWorks,
4870 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
4871 stub on the target system.
4873 New CPUs supported include the AMD 29000 and Intel 960.
4875 GDB now reads object files and symbol tables via a ``binary file''
4876 library, which allows a single copy of GDB to debug programs of multiple
4877 object file types such as a.out and coff.
4879 There is now a GDB reference card in "doc/refcard.tex". (Make targets
4880 refcard.dvi and refcard.ps are available to format it).
4883 * Control-Variable user interface simplified
4885 All variables that control the operation of the debugger can be set
4886 by the ``set'' command, and displayed by the ``show'' command.
4888 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
4889 ``Show prompt'' produces the response:
4890 Gdb's prompt is new-gdb=>.
4892 What follows are the NEW set commands. The command ``help set'' will
4893 print a complete list of old and new set commands. ``help set FOO''
4894 will give a longer description of the variable FOO. ``show'' will show
4895 all of the variable descriptions and their current settings.
4897 confirm on/off: Enables warning questions for operations that are
4898 hard to recover from, e.g. rerunning the program while
4899 it is already running. Default is ON.
4901 editing on/off: Enables EMACS style command line editing
4902 of input. Previous lines can be recalled with
4903 control-P, the current line can be edited with control-B,
4904 you can search for commands with control-R, etc.
4907 history filename NAME: NAME is where the gdb command history
4908 will be stored. The default is .gdb_history,
4909 or the value of the environment variable
4912 history size N: The size, in commands, of the command history. The
4913 default is 256, or the value of the environment variable
4916 history save on/off: If this value is set to ON, the history file will
4917 be saved after exiting gdb. If set to OFF, the
4918 file will not be saved. The default is OFF.
4920 history expansion on/off: If this value is set to ON, then csh-like
4921 history expansion will be performed on
4922 command line input. The default is OFF.
4924 radix N: Sets the default radix for input and output. It can be set
4925 to 8, 10, or 16. Note that the argument to "radix" is interpreted
4926 in the current radix, so "set radix 10" is always a no-op.
4928 height N: This integer value is the number of lines on a page. Default
4929 is 24, the current `stty rows'' setting, or the ``li#''
4930 setting from the termcap entry matching the environment
4933 width N: This integer value is the number of characters on a line.
4934 Default is 80, the current `stty cols'' setting, or the ``co#''
4935 setting from the termcap entry matching the environment
4938 Note: ``set screensize'' is obsolete. Use ``set height'' and
4939 ``set width'' instead.
4941 print address on/off: Print memory addresses in various command displays,
4942 such as stack traces and structure values. Gdb looks
4943 more ``symbolic'' if you turn this off; it looks more
4944 ``machine level'' with it on. Default is ON.
4946 print array on/off: Prettyprint arrays. New convenient format! Default
4949 print demangle on/off: Print C++ symbols in "source" form if on,
4952 print asm-demangle on/off: Same, for assembler level printouts
4955 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
4958 * Support for Epoch Environment.
4960 The epoch environment is a version of Emacs v18 with windowing. One
4961 new command, ``inspect'', is identical to ``print'', except that if you
4962 are running in the epoch environment, the value is printed in its own
4966 * Support for Shared Libraries
4968 GDB can now debug programs and core files that use SunOS shared libraries.
4969 Symbols from a shared library cannot be referenced
4970 before the shared library has been linked with the program (this
4971 happens after you type ``run'' and before the function main() is entered).
4972 At any time after this linking (including when examining core files
4973 from dynamically linked programs), gdb reads the symbols from each
4974 shared library when you type the ``sharedlibrary'' command.
4975 It can be abbreviated ``share''.
4977 sharedlibrary REGEXP: Load shared object library symbols for files
4978 matching a unix regular expression. No argument
4979 indicates to load symbols for all shared libraries.
4981 info sharedlibrary: Status of loaded shared libraries.
4986 A watchpoint stops execution of a program whenever the value of an
4987 expression changes. Checking for this slows down execution
4988 tremendously whenever you are in the scope of the expression, but is
4989 quite useful for catching tough ``bit-spreader'' or pointer misuse
4990 problems. Some machines such as the 386 have hardware for doing this
4991 more quickly, and future versions of gdb will use this hardware.
4993 watch EXP: Set a watchpoint (breakpoint) for an expression.
4995 info watchpoints: Information about your watchpoints.
4997 delete N: Deletes watchpoint number N (same as breakpoints).
4998 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
4999 enable N: Re-enables watchpoint number N (same as breakpoints).
5002 * C++ multiple inheritance
5004 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5007 * C++ exception handling
5009 Gdb now supports limited C++ exception handling. Besides the existing
5010 ability to breakpoint on an exception handler, gdb can breakpoint on
5011 the raising of an exception (before the stack is peeled back to the
5014 catch FOO: If there is a FOO exception handler in the dynamic scope,
5015 set a breakpoint to catch exceptions which may be raised there.
5016 Multiple exceptions (``catch foo bar baz'') may be caught.
5018 info catch: Lists all exceptions which may be caught in the
5019 current stack frame.
5022 * Minor command changes
5024 The command ``call func (arg, arg, ...)'' now acts like the print
5025 command, except it does not print or save a value if the function's result
5026 is void. This is similar to dbx usage.
5028 The ``up'' and ``down'' commands now always print the frame they end up
5029 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5030 frames without printing.
5032 * New directory command
5034 'dir' now adds directories to the FRONT of the source search path.
5035 The path starts off empty. Source files that contain debug information
5036 about the directory in which they were compiled can be found even
5037 with an empty path; Sun CC and GCC include this information. If GDB can't
5038 find your source file in the current directory, type "dir .".
5040 * Configuring GDB for compilation
5042 For normal use, type ``./configure host''. See README or gdb.texinfo
5045 GDB now handles cross debugging. If you are remotely debugging between
5046 two different machines, type ``./configure host -target=targ''.
5047 Host is the machine where GDB will run; targ is the machine
5048 where the program that you are debugging will run.